When AT&T Inc. opened its Foundry product development center in Georgia Tech’s Technology Square on August 27, 2013, the company gained a prominent place in an innovation ecosystem acknowledged as a leader in fostering both technology and business innovation.
In its new location in the Centergy building on the edge of the Georgia Tech campus, the AT&T Foundry connects to the Institute’s students, research program – and dozens of early-stage technology companies being incubated through Georgia Tech’s Advanced Technology Development Center (ATDC), VentureLaband Flashpoint initiatives. Georgia Tech’s incubation and acceleration programs are rated among the top such efforts worldwide by observers such as Forbes Magazine and Stockholm-based UBI Index.
Moreover, AT&T’s new location places it close to Georgia Tech’s many faculty-student research teams, as well as a variety of business and startup support groups located in midtown Atlanta. And the Foundry is just a few floors away from other major multinational companies in the Centergy Building: the Panasonic Innovation Center and the ThyssenKrupp Elevator Americas innovation facility. NCR Corp.’s Mobile Development Team is headquartered a block away at the Biltmore on West Peachtree Street.
“When we locate a Foundry facility, our number one criterion is to be part of an ecosystem that fosters innovation – which usually occurs at the intersection of premier education, high technology and an entrepreneurial mindset – and those are all things that we found at Technology Square,” said Ralph de la Vega, president and CEO of AT&T Mobility. “When I saw the startup company incubators there, and the entrepreneurs and the high-quality technical people from Georgia Tech driving them, I knew this is where we needed to be. In fact, we’re already talking with a startup whose technology could significantly benefit our product offerings.”
In addition to Georgia Tech, the Foundry is collaborating with networking leader Cisco Systems Inc., which employs nearly 2,000 people in the metro Atlanta area. Working with Cisco, AT&T will concentrate on developing products for Digital Life, AT&T’s home security and automation service.
The team will also create new applications and services related to such focus areas as the connected car, mobility, emerging devices and AT&T U-verse. Cisco will collaborate with AT&T on projects, and will also help identify key third-party developers, startups, investors, inventors and other entrepreneurs to bring into the facility.
The $3 million total Foundry investment stems from the joint efforts of AT&T, Cisco and Georgia Tech, along with state and local involvement. The Foundry in Atlanta is only the fourth such venture for AT&T – the company has similar centers in Palo Alto, Calif.; Plano, Texas, and Tel Aviv, Israel.
The many startups found in Technology Square are largely a result of the ATDC startup accelerator, which provides coaching, connections and even office space to many young Georgia companies. ATDC’s work is aided by Flashpoint, which helps early-stage startups minimize risk and accelerate growth, and by VentureLab, which focuses on turning discoveries by Georgia Tech faculty, research staff and students into new companies.
“I think it’s widely recognized that the Technology Square innovation zone offers one of the world’s top business support infrastructures,” said Stephen Fleming, vice president and executive director of Georgia Tech’s Enterprise Innovation Institute, which oversees ATDC and VentureLab. “A critical mass has been forming around Georgia Tech based on a multi-faceted innovation environment, and companies come here because they’re attracted by that range of capabilities, not just by a single center or research team or partner.”
AT&T’s interest in coming to Technology Square was supported by Georgia Tech outreach efforts aimed at helping potential partners with insight and ease of access to the innovations, new technologies and startup ventures developed and supported by Georgia Tech. Greg King of Georgia Tech’s Strategic Partners Office worked with AT&T as it examined the Georgia Tech and Atlanta environment.
“When you look at everything we’re doing in the intersection of people and technology, the startup community, and the exciting faculty and student innovation – a Technology Square location was a great choice for AT&T, as it has been for other corporate partners like NCR, Panasonic and ThyssenKrupp,” King said. “The Institute for People and Technology, the Georgia Tech Research Institute and ATDC’s Industry Connect program that helps larger companies connect with relevant startup companies – all played a part in the selection of this area for AT&T’s Foundry.”
Making Georgia Tech accessible to potential industry partners is a top priority, said Stephen E. Cross, executive vice president for research. The Institute’s expanded outreach toward industry, which organizes more than 200 research centers and laboratories into a dozen core research areas, helps make Georgia Tech more accessible and understandable.
“Georgia Tech was founded with a mandate to foster economic development and to conduct research with relevance,” said Cross. “Our innovation ecosystem helps give Georgia businesses – and multinational partners such as AT&T and others – straightforward access to our world-class basic and applied research capabilities and our ‘One Georgia Tech’ collaborative environment.”
Panasonic Automotive Systems Company of America opened an innovation center in the Centergy Building in November 2012. Initially, Panasonic opened the facility to gain access to Georgia Tech students and to north Atlanta residents for its headquarters based in Peachtree City, Ga., said John Avery, group manager for the Panasonic Innovation Center.
But once the new innovation location was up and running, he said, it became clear that the Georgia Tech and Technology Square environment could directly benefit product development at the Automotive Systems Division, which focuses on infotainment systems, sensors, switches, power systems and other products for vehicles.
“We’re increasing our innovation focus, connecting with the startup community in midtown and participating in all the good things that are going on there – ATDC and Flashpoint and the Midtown Alliance,” he said. “There are a lot of great things happening at once, which are making midtown into a really significant location.”
Panasonic’s Centergy offices currently have space for about 40, Avery said. The center employs a number of Panasonic staffers, along with Georgia Tech students in intern and co-op roles.
Panasonic recently sponsored the Convergence Innovation Competition (CIC) for students, and plans to sponsor other student efforts such as senior Capstone Design projects. In addition, Avery said, innovation center executives plan to approach companies incubated at Georgia Tech and in the metro area about potential business opportunities with Automotive and other Panasonic divisions.
NCR opened an R&D center in the Centergy Building nearly three years ago to hire Georgia Tech students and work on mobile applications and cloud computing technologies. That effort was successful – so much so that the center soon moved to a larger space in the nearby Biltmore, which became home to the NCR Mobile Development Team.
“Our first office was in Centergy, giving us direct access to new Georgia Tech grads and interns,” said Daniel Bassett, senior director of product development in NCR’s Hospitality line of business. “From there, we needed a larger space and moved into the Biltmore, which offered us room to grow in a perfect environment. Employees love the space and it has become our number one recruiting tool as we look to bring on the next wave of software development talent.”
Today, the Mobile Development Group’s R&D center has more than 50 employees – mostly full-time – at the Biltmore location, and expects to add up to 15 new people each year, he said.
Currently, NCR is collaborating with a Georgia Tech faculty-student research team on a project involving the unstructured analysis of “big data,” massive information sets that require special computation tools. In addition, the group is engaged with several small Georgia companies through the Flashpoint accelerator, and expects to be involved in Capstone Design courses in which Georgia Tech students develop real world prototypes.
“We’re focused on building some of the best consumer facing mobile apps in the restaurant industry – and access to the skilled and highly motivated people we encounter at Georgia Tech is a critical part of our development strategy,” Bassett said.
ThyssenKrupp Elevator Americas is heavily invested in the U.S., with a manufacturing plant and research center in Tennessee. The company conducted a lengthy assessment of U.S. engineering colleges before deciding to site its innovation facility at Georgia Tech, said Thomas Felis, vice president for innovation management.
“We evaluated the scores of major U.S. engineering programs on a national basis, and considered what you might call the personality of each university,” he said. “Georgia Tech was a more hands-on school than others – which is what we were looking for. And when we also considered the infrastructure, the lab space available, and the Georgia Tech Manufacturing Institute, we decided to come here.”
Felis said that the ThyssenKrupp Elevator Innovation Center, which opened in January 2013, is already working with two Georgia Tech startup companies. The aim of the collaborations is to develop human interface improvements that could enhance elevator technology.
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]]>When scientists and engineers use the word materials, they mean any naturally occurring substance manipulated by humans to make things. Beginning with the first metals, discovered by trial and error thousands of years ago, the drive to develop materials that better serve human needs has played a central role in the rise of complex societies.
Modern researchers have moved past haphazard experimentation. Today they examine materials at every level – from the nanoscale to the visible and tangible macroscale – to understand why a material behaves as it does.
At Georgia Tech, investigators unite research capabilities with powerful new tools to develop and characterize novel materials. By pinpointing the complex physical and chemical interactions that control performance, they are creating materials with unique properties.
The White House recently stressed the economic importance of materials expertise when it launched the Materials Genome Initiative, aimed at speeding the pace with which advanced materials move from discovery to industry applications. Georgia Tech is well positioned with the Institute for Materials (IMat), established in 2013 as one of nine interdisciplinary research institutes on campus.
Interdisciplinary collaboration is a critical concept at Georgia Tech, explained David McDowell, a Regents’ Professor who is founding executive director of the new institute. Accordingly, IMat is emphasizing collaboration throughout campus and beyond.
“At Georgia Tech we have some 200 faculty who focus on materials research,” said McDowell, who is the Carter N. Paden Jr. Distinguished Chair in Metals Processing in the Woodruff School of Mechanical Engineering, with a joint appointment in the School of Materials Science and Engineering. ”They tackle a broad range of areas including materials for electronics, infrastructure, energy, environment, transportation, biotechnology, aerospace and defense. The very breadth of that research makes multidisciplinary collaboration both possible and desirable.”
The campus is home to numerous interdisciplinary materials groups – including the Materials Research Science and Engineering Center, the Center for Organic Photonics and Electronics, and the Institute for Electronics and Nanotechnology – that bring together dozens of faculty researchers to focus on core problems.
Materials research at Georgia Tech addresses every type of material, including metals, ceramics, polymers, textiles, composites, nanomaterials, bio-molecular solids – even familiar yet indispensable concrete. And cutting-edge structures that combine very different materials can offer unique capabilities – as in the case of spider silk and graphene oxide, which yield a light, flexible material stronger than steel.
“In the past, materials progress was highly empirical, based largely on trial and error,” said professor Naresh Thadhani, chair of the School of Materials Science and Engineering, which is the largest single locus of materials research at Georgia Tech, with 37 full-time faculty and 20 courtesy faculty appointments. “That approach is now widely regarded as excessively slow and costly.”
Instead, Thadhani explained, researchers are using microstructural tools, including optical and electron microscopes and neutron and X-ray scattering techniques, combined with time-resolved experimentation, mathematical and numerical modeling and computational simulations, to characterize materials. The aim is to predict how they’ll perform in real world applications, to accelerate the pace from discovery to deployment.
The ability to develop new materials for advanced manufacturing is essential to the United States, said Stephen E. Cross, executive vice president for research at Georgia Tech. In the new global economy, novel materials will be a key to the nation remaining competitive.
“From the day it opened, Georgia Tech has stressed support for industry, and interdisciplinary research is something we believe in very strongly as well,” said Cross. “I’m confident that our broad materials research capability, fostered by our Institute for Materials, can deliver innovations that will promote economic growth for both the state of Georgia and the nation.”
This article presents an overview of materials work at Georgia Tech, focusing on a few of the many innovative research projects underway.
Everyone wants to be confident that jet engines are completely dependable. Richard W. Neu, a professor in the Woodruff School of Mechanical Engineering, studies the details of exactly this issue.
With funding from the Department of Energy and several multinational corporations, Neu has focused on fatigue and fracture of metallic alloy systems for nearly two decades. He specializes in high temperature fatigue and fracture behavior – how the microstructure of highly stressed metal parts changes over time.
“We’re developing models to capture the evolution of gas turbine engine parts over time, so we can predict how that microstructure will change with operational conditions,” said Neu, who directs the Mechanical Properties Research Laboratory at Georgia Tech.
Neu and his research team are studying gas turbine engines for both aerospace use and for land-based power generation. In both cases, gases in excess of 1,400 degrees Celsius – higher than the melting point of most metals – require active cooling strategies and parts made of special alloys to survive these harsh conditions.
In such demanding environments, the high temperatures and stress always take a toll, Neu said. “Among other investigations, we’ve taken a used engine blade, in service for about three years, and compared its microstructure to an unused blade,” said Neu, who also teaches in the School of Materials Science and Engineering. “And I can tell you, they’re vastly different.”
What’s more, he said, the differences are not uniform. The microstructure of engine parts can vary dramatically depending on the combined temperature and stress cycles – meaning exactly how and when the parts encountered temperature and stress. Neu simulates these complex thermomechanical cycles in the laboratory to characterize the degradation of the material under operational conditions.
The materials that Neu tests are typically nickel-based superalloys, which are widely used in gas turbine engines. More recently, he’s been studying promising new high temperature materials such as gamma titanium aluminides, which are so lightweight that they could be revolutionary for aerospace applications.
How long a material will last in a given application is always a major concern. Preet Singh, a professor in the School of Materials Science and Engineering (MSE), is pursuing a number of studies to see how well metallic alloys stand up to various corrosive environments and stresses.
Singh and his team are looking at the performance of conventional carbon steel pipelines used to transport fuel products such as gasoline. In work sponsored by the Department of Transportation and the pipeline industry, he’s addressing the role of corrosion and stresses in the environmental degradation of steel, which can potentially lead to pipeline failure.
Among other things, he’s studying whether pipeline integrity could be affected by new biofuels.
“Biofuels such as ethanol, bio-diesel, or bio-oils like pyrolosis oil are becoming increasingly important, so there is concern about how they may affect pipeline interior surfaces,” he said. “We are examining the interactions between these chemicals and steel pipelines – studying factors including stress, internal environment and the alloy composition – to understand the possible issues and the ways to mitigate them.”
The problem is a complex one, Singh explains. The iron oxides – rust – that form when steel begins to corrode may also create a passive film that can help protect the pipeline interior from being further damaged by chemicals flowing through.
At the same time, different types of iron oxides display very different characteristics. For example, if iron oxide molecules clump rather than dispersing smoothly and continuously, or make a defective surface film, then surface protection is greatly reduced.
High flow velocities can injure protective films as well. Damage can also come from the stresses placed on steel as sequential fuel batches pressurize and then depressurize the pipeline, which causes low frequency fatigue in these structures.
Results from Singh’s research have shown that a small amount of impurities such as water, or chlorides in biofuels, can actively affect the extent and mode of corrosion in pipelines as well. Working with MSE associate professor Seung Soon Jang, Singh is studying how very small differences in the ratio of water and ethanol can have a big effect on the corrosion taking place inside a pipe.
Advanced metal alloys have become indispensable in various emerging technologies – especially where extreme conditions demand new levels of performance and lighter weight. But developing novel alloys is difficult without a thorough understanding of metal microstructure.
“We can no longer afford to depend on the element of luck in developing materials,” said Surya Kalidindi, a professor in the Woodruff School of Mechanical Engineering. “Today, interdisciplinary research has enabled us to capture materials knowledge that makes it much easier for the designer or manufacturing engineer to understand the microstructure – and this knowledge lets them deploy new technology much faster.”
In projects funded by the Department of Defense, Kalidindi and his team are researching ways to improve lightweight structural metals used in the transportation sector. The goal is to increase operating temperatures in service, which would translate to higher efficiency and major fuel savings.
But developing new alloys requires more than familiarity with the relevant metals chemistry, Kalidindi explained. The materials designer needs to understand how the crystals within a metal alloy fit together at the micron level, an interaction that has far-reaching effects on properties.
The solution is a computer database containing in-depth information on the internal makeup of many different materials, he said. The data on these properties are derived from experiments conducted by Kalidindi and many other researchers.
“In some ways you can compare this approach to a fingerprint database, where you can quickly compare a new print coming in to similar ones based on its characteristics,” he said. “We have developed techniques that allow us to represent each microstructure’s characteristics three-dimensionally, so we can look at a new material and see how it is similar to structures on which we already have detailed information.”
In two National Science Foundation-funded projects, Kalidindi is studying development of lighter weight automobile parts made of either high-strength steels or new types of magnesium alloys. Among the challenges is the need to find technologies that can reduce vehicle weight yet cost no more than current techniques.
In materials research, investigators often alter structures at or near the atomic scale to change behavior at the macroscale.
Massimo Ruzzene, a professor in the Guggenheim School of Aerospace Engineering (AE), takes a different approach. He designs metamaterials, which are artificial composite structures that combine two or more components in patterns that give them properties not found in materials derived from nature.
In a metamaterial, the geometry of the constituent parts lets it react to incoming wave energy – such as electromagnetic, sound or shock waves – in unusual ways. For example, traditional materials expand in one direction when compressed in another direction; a metamaterial could be designed to adapt to the force in a unique way, such as compressing in both directions.
“From my standpoint, structures and materials are becoming the same thing,” said Ruzzene, who directs AE’s Vibration and Wave Propagation Laboratory. “We work on what you might call atomically inspired structures. Rather than manipulating things at the molecular level, we look at molecules for design ideas – for concepts we can use at the larger scales to design artificial composite materials with geometries that give them unique properties.”
For instance, molecules at the smaller scales often realign under a stimulus, such as heat. In a metamaterial, that realignment might be imitated to improve the macroscale functioning of, say, a lattice structure that’s good at dissipating incoming energy but has poor strength.
To achieve this, researchers could add in elements – such as aluminum, rubber or simply air – which are carefully placed into the lattice geometry. These inclusions would enable the structure to change dramatically when exposed to a given type of stress, altering overall behavior and changing the directionality of incoming stress waves.
In one federally funded project, Ruzzene is developing a structure with both high stiffness and high damping – a demanding task because these properties conflict. Ruzzene and his team decided to decouple the two requirements, creating a structure that is stiff on the outside but uses resonating structures inside to damp out problem frequencies.
This approach could be useful in reducing structural fatigue caused by continual flexing in aircraft. The research team has developed an aluminum beam that fits inside an aircraft wing. The metamaterial design lets it carry a load and stiffen the wing, while also drastically reducing vibrations by means of damping in the critical range of 8 to 10 hertz.
Tests that show when a material will fail are critical to reliable engineering applications. The problem is that such tests are generally complex and expensive. They’re also time-consuming, slowing the insertion of new material designs into real world applications.
Julian J. Rimoli, an assistant professor in the Guggenheim School of Aerospace Engineering (AE), works in the field of computational solid mechanics, which investigates the behavior of any solid material – including metals, ceramics, polymers, composites and metamaterials – through advanced modeling and computational techniques. In particular, he is interested in the formulation of models that can dependably predict the life of materials in extreme environments.
“Traditionally, engineering models of degradation, wear, damage, and failure of materials are phenomenological. This phenomenological approach implies that models are formulated to fit experimental observations,” he said.
While this approach is good enough in many situations, he added, it is inherently not predictive. In addition, this approach does not provide any physical insight on why a material may have certain properties.
Rimoli specializes in the formulation of physics-based predictive multiscale models that link microstructure to mechanical behavior. His research aims to design new classes of materials that are more resistant to extreme conditions.
In one Air Force-sponsored project, Rimoli is trying to understand the leading erosion mechanisms in plasma thrust engines, which can be used to propel satellites.
His research shows that there are more erosion mechanisms than previously thought, such as mesoscale formation of inter- and intra-granular thermal cracks that play a prominent role in the premature wear of such components. These models are currently being used to tailor the microstructure of families of heterogeneous ceramic compounds to better withstand the demands of a plasma environment.
Professor Min Zhou of the Woodruff School of Mechanical Engineering (ME) studies the effects of mechanical, thermal and chemical loading on the behaviors and reliability of structural, infrastructural and functional materials, such as metals, ceramics, semiconductors and composites. One focus involves high strain rate mechanical loading, which can come from several causes, including high-speed machining, impact, penetration, and the explosion of energetic materials.
As part of a federally funded project, Zhou has built a laboratory in the Georgia Tech Manufacturing Institute to investigate how ship structures respond to the effects of underwater explosions. Using a special gas-driven gun, he generates high-pressure waves through water and uses the impulsive loads to analyze the resulting fluid-solid interactions with high-speed digital cameras and laser interferometers.
The goal is to develop new materials for ship construction. Under special consideration are sandwich structures, which are polymer-based composites that are lightweight, inexpensive and highly corrosion resistant.
But such materials must also be highly resistant to heavy weather, encounters with reefs and other threats. Using both experiments and computer simulations, Zhou is designing composite structures that could meet these requirements.
In another project, sponsored by the Army and the Department of Homeland Security, Zhou is working with ME professor David McDowell on infrastructure materials that could offer increased protection against earthquakes, as well as terrorist attacks. The team is using both large-scale experiments and computational modeling techniques to study ultra-high-performance concrete designs that use novel metal fibers for added strength.
Zhou also studies a range of issues related to materials in energy applications. In a project sponsored by the National Research Foundation of Korea, he is addressing problems surrounding the use of silicon to replace graphite in next-generation high-capacity rechargeable lithium ion batteries.
Silicon is a highly desirable replacement for traditional graphite as anodes in lithium-ion batteries, because of its much higher lithium storing capacity. However, it is more prone to mechanical failure through cracking due to large volume changes during charge and discharge. Zhou is developing models that outline approaches for improving the reliability of silicon-based anodes by taking advantage of the size dependence of coupled mechanical chemical diffusional processes in the materials.
Composites such as carbon fiber reinforced polymers are impressively light and strong, but they don’t have the track record of older materials like steel. Chuck Zhang, a professor in the Stewart School of Industrial and Systems Engineering, is working with aerospace companies to increase the quality of composite parts while lowering production costs and ensuring structural integrity long term.
“Unlike steel parts, which can be stamped, composites generally require time-consuming molding and curing processes,” Zhang said. “We are researching methods for shortening the composites’ manufacturing time while improving the quality of finished parts – and also adding a self-sensing capability that can perform structural health monitoring.”
Detecting problems and flaws during composite manufacturing and service is critical because such flaws can go unseen and lead to sudden failure. To guard against such flaws, as well as long-term structural fatigue problems, Zhang is working on novel methods for making composites with tiny built-in sensors that could monitor both the manufacturing process and composite structural integrity during service.
Conventional strain sensors – usually thin films of metal – would constitute a foreign body within the polymer composite itself, he explained. Their presence could affect integrity and lead to adverse delamination of composite layers.
Zhang uses special aerosol jet printing equipment to fabricate tiny sensors directly on composites using conductive inks comprised of carbon nanotubes, graphene or metal particles. These sensors – with feature sizes of about 10 microns – are far smaller than conventional strain sensors. They have more choices for ink materials and can be printed on substrates of various materials and shapes, which allow them to be more conformal, versatile and easily embedded. Their tiny size could let manufacturers build large numbers of them into polymer composites without disturbing structural integrity.
In other research, Zhang is working on a prosthetics-related project with Ben Wang, who is executive director of the Georgia Tech Manufacturing Institute (GTMI). The researchers are participating in the Socket Optimized for Comfort with Advanced Technology (SOCAT), a $4.4 million Department of Veterans Affairs contract led by Florida State University.
The effort addresses prosthetics shortcomings to benefit those who have lost limbs to injury or disease. The GTMI team is developing tiny printed sensor devices to monitor health- and comfort-related conditions in the socket where a patient’s limb connects to a prosthesis.
Zhang is also collaborating with researchers Xiaojuan (Judy) Song and Jud Ready of the Georgia Tech Research Institute to develop innovative sensors and photovoltaic devices.
Kimberly Kurtis, a professor in the School of Civil and Environmental Engineering, is pursuing multiple research projects involving a ubiquitous composite material: concrete.
Her research involves studies that range from chemistry and structure at the nanoscale to appraising massive structures such as dams and buildings at the macroscale.
“Our work is very multiscale, and like other materials researchers, we’re constantly trying to better define the relationship between structure and properties,” said Kurtis. “To do that, we study the broader class of all cement-based materials – not just concrete but anything that contains a mineral, non-biological cement – to link the chemistry of various cements with their structural performance.”
In one National Science Foundation (NSF)-sponsored project, Kurtis and her team studied the use of titanium dioxide nanoparticles as partial replacements for cement. They found the material significantly alters the way that the cement reacts, reducing the time it takes to cure, and potentially reducing the amount of cement needed to build a structure.
The team is also studying the role of titanium dioxide and concrete’s nanostructure in potentially reducing nitrogen oxide effects. Nitrogen oxides, a group of compounds that are major byproducts of vehicle emissions, can damage human health. Tailoring the interactions between concrete and its environment could lead to new approaches for improving air quality.
Among several other projects, Kurtis is working with NSF support to develop better statistical and probabilistic descriptors of concrete and its constituents, with a focus on nanoscale and micron-scale porosity. Concrete is heterogeneous, she explained, and its composition varies on multiple scales, from coarse aggregate to paste. Data on these related factors can be used in computer models to predict performance.
“An exciting thing about being at Georgia Tech is that you’ve always got one foot in science and one foot in practice,” Kurtis said. “You want to make sure that what you’re doing is relevant to the broader needs of society.”
At the Georgia Tech Research Institute (GTRI), a composite developed for radioactive materials surveillance is being adapted for medical imaging applications. The goal is a new technology – the transparent nanophotonic scintillator for X-ray imaging – that exposes patients to less radiation while producing higher resolution images.
The basic technology development was led by GTRI researchers Brent Wagner and Bernd Kahn with Department of Homeland Security funding. The team created a unique composite made of nanoparticles of rare earth materials dispersed evenly in a silica matrix. The glasslike material detects gamma rays by converting them to visible light via a phenomenon known as scintillation.
A similar approach is now being developed under a National Institutes of Health-funded project led by GTRI senior research engineer Zhitao Kang, a member of Wagner’s research group. Kang is using the same basic scintillator material – nanoparticles in a glass matrix – to produce a clearer image with far less light scattering than conventional X-ray imaging scintillators.
To improve the technology further, Kang and his team have been working with professor emeritus Christopher Summers of the School of Materials Science and Engineering to add a layer of photonic crystals to the scintillator’s surface. The photonic crystals – basically a pattern of tiny holes tuned to a specific light frequency – help direct light out of the scintillator and thus increase light output.
“Our scintillator – the nanoparticles in glass – gives us high resolution, while the photonic crystals increase the light collection efficiency, which means we get more light out of the X-ray,” Kang said. “These are the two properties you want – a better image, along with high efficiency so you don’t need to use so many X-rays.”
Kang pointed to an added benefit of the nanophotonic approach: GTRI’s glass-like scintillator materials could be made in large sheets, just like industrial glass. That would decrease manufacturing overhead and make the technology less costly.
Kang and his team are also collaborating with Oak Ridge National Laboratory and a German national laboratory to modify GTRI’s scintillator so that it can detect neutrons. The researchers are adding neutron-detecting materials – varieties of lithium and boron – that can absorb incoming neutron energy and convert it to light via the scintillation process.
Carbon fibers are stronger and lighter than steel, and composite materials based on carbon fiber reinforced polymers are used in an ever-expanding range of applications. The Boeing 787 aircraft employs carbon fiber materials extensively in its fuselage, wings, tail and other sections. Carbon fiber composites are utilized in civil engineering and construction, and in many consumer products.
Satish Kumar, a professor in the School of Materials Science and Engineering, leads a DARPA project to improve composite materials that are based on carbon fibers by using nanotechnology in the form of carbon nanotubes. Here he views magnified carbon fibers. (Click image for high-resolution version. Credit: Gary Meek)
Yet today’s carbon fiber materials have a long way to go before they achieve their full potential, said Satish Kumar, a professor in the School of Materials Science and Engineering. He is leading a four-year, $9.8 million project sponsored by the Defense Advanced Research Projects Agency (DARPA) to improve these materials using nanotechnology in the form of carbon nanotubes.
“It’s likely that carbon fiber materials could be about 10 times stronger than they are presently, so there is tremendous room for further improvement in their tensile and other structural properties,” Kumar said. “By using carbon nanotubes to reinforce carbon fibers, our objective is development of a next-generation carbon fiber with double the tensile strength of today’s strongest carbon fibers.”
In an advanced laboratory established for the current project, Kumar and his team are optimizing techniques for converting polymeric materials into high-strength carbon fiber, using a multi-stage process.
Untreated polymers contain carbon, hydrogen, oxygen and nitrogen, Kumar explained. They can be made into carbon fiber via a selective treatment process called pyrolysis, in which a polymer mix is gradually subjected to both heat and stretching. This treatment eliminates large quantities of hydrogen, oxygen and nitrogen, leaving an increased amount of carbon that makes the fiber stronger.
Kumar modifies this process by adding carbon nanotubes – about one percent by weight – to the polymer mixture before pyrolysis. Among the challenges is finding the best methods for dispersing the carbon nanotube solution uniformly in the polymer mix.
“If the mixing process is fully successful, the carbon nanotubes will reorient the crystals within the polymer in a uniform direction,” he said. “The altered molecular structure has the potential to make the resulting carbon fiber much stiffer and stronger.”
Carbon nanomaterial-based chemiresistors are useful for environmental monitoring and agricultural applications.
Xiaojuan (Judy) Song, a senior research scientist at the Georgia Tech Research Institute (GTRI), has developed sensing technology that uses functionalized carbon nanotubes to detect minute amounts of chemicals in ambient air. Combined with radio frequency identification (RFID) electronics, this material could be used to make low-cost sensors that give advance warning of threats.
“We are using carbon nanotubes (CNT) that have been functionalized for a particular gas or analyte, applied as a sensing film,” said Song, who is the principal investigator on the project. “Sensors based on these materials could be used in the field by the thousands to inform first responders about nearby hazards.”
Working with graduate student Christopher Valenta of the School of Electrical and Computer Engineering, Song has developed a prototype sensor array integrated with an RFID chip that is 10 centimeters square. The next step might be a prototype as small as a one centimeter square, with sensing tips that could be aerosol jet printed on paper or a flexible substrate.
The RFID-enabled CNT-based wireless sensors could also be valuable for monitoring air pollution, she said. Low-cost sensing systems that detect trace ammonia, nitrogen oxides and other targeted gases could also be fielded in large numbers for agricultural applications, such as providing information on fertilizer usage and early detection of plant disease.
Robert Speyer, a professor in the School of Materials Science and Engineering, performs extensive research on the body armor that protects U.S. troops.
He also builds it.
His Atlanta-based Georgia Tech spinoff company, Verco Materials LLC, produces ceramic armor made primarily from boron carbide. Using patented processes, Verco has for several years been producing armor for research and development, as well as for actual protective equipment. To date, Verco has received some $6 million in contracts to expand the company and its capabilities.
Verco recently started work to improve side armor plates, which are used by U.S. troops to augment the protection offered by the familiar front torso plates.
“The most important objective in ceramic body armor is to have high hardness, so that the armor will not flow out of the way of the projectile. Instead, the projectile is forced to dwell at the surface, collapsing on itself and mushrooming out as it loses its energy,” Speyer said. “Our armor is really impressive in that regard, which is allowing us to develop armor at reduced weight that still defeats armor piercing rounds.”
Verco now has two 6,000-square-feet manufacturing locations in Atlanta, not far from the Georgia Tech campus. One location includes a massive 1,700-ton press capable of making powder compacts of full torso armor plates.
Among the challenges that Verco has overcome is a need to find less expensive boron carbide powders to use in making armor plate. The team solved that problem by devising a different formulation with an even higher hardness.
“Our ballistics results are disruptively good,” Speyer said. “As we scale up, we’re focusing on the need to keep our costs competitive as well.”
Since World War I, the U.S. military has used protection equipment – including gas mask-type devices and larger filters – to protect against possible chemical agents. Krista Walton, an associate professor in the School of Chemical and Biomolecular Engineering, works to ensure that U.S. air purification technology is equal to any class of chemicals, novel or conventional.
Walton and her research team focus on designing materials that are effective against a broad class of compounds called toxic industrial chemicals (TICs). They have developed porous materials that are designed to adsorb incoming TICs, protecting personnel against their effects for extended periods of time.
“There are a number of materials that for decades have protected effectively against many different chemicals,” Walton said. “Our work centers on finding ways to enhance filtration devices, to be sure they can also handle any new air purification challenges that emerge.”
With funding from the Defense Threat Reduction Agency and the Army Research Office, Walton and her research group are developing nanostructured porous materials that can effectively capture additional toxic chemicals. The goal is to improve performance in devices that range from gas masks to filters that protect the air intake equipment used in buildings.
One of the group’s principal research efforts focuses on metal organic framework (MOF) technology. These hybrid materials, which use both inorganic and organic parts, are designed to trap specific molecules that could be hazardous.
In this approach, organic ligands – molecules that bind to metal atoms – are modified to target one specific incoming molecule but not others. Several different ligands can be mixed together to protect against a range of different chemicals.
Walton uses a variety of tools, including powder X-ray diffraction and gas adsorption analysis, to characterize the materials she develops. The aim is to pinpoint materials with the most promise, which are then selected for more extensive testing.
Natural structures can be far more complex than anything developed synthetically. Kenneth Sandhage, who is the B. Mifflin Hood Professor in the School of Materials Science and Engineering (MSE), is using tiny diatoms – a type of single-celled algae – to make unique materials with a variety of potential applications.
In nature, there are an estimated 100,000 species of diatoms, ranging from a few micrometers to several hundred micrometers in size. Each species creates a unique three-dimensional frustule, or micro-shell, out of silica, a material also used to make glass.
Once researchers identify a diatom configuration that holds promise for a specific application, that species may be allowed to reproduce in a laboratory culture. In 80 reproduction cycles, one parent diatom can produce more than a septillion daughters of similar three-dimensional structure.
“It’s massively parallel self-assembly, under precise 3-D control, that can be accomplished in a wide variety of shapes by using different diatom species,” Sandhage explained. “There’s no man-made approach that can accomplish such massively parallel 3-D assembly in such a range of complex patterns under ambient conditions.”
To make useful structures, the next step involves synthetic chemical processes, as the complex but delicate silica shell is replaced with a more desirable functional material suitable for a particular application. Sandhage and his research team have made ceramic and polymer replicas of diatom frustules composed of, for example, titanium oxide, magnesium oxide, silicon carbide, carbon, and barium titanate. They’ve also made replicas from silicon and other elements such as copper, silver, gold, platinum and other metals.
In one project, Sandhage and his team have worked with Meilin Liu, a Regents’ Professor in the School of Materials Science and Engineering, to use a diatom-derived material in polymer electrolyte membrane fuel cells. To speed up the critical oxygen reduction reaction in the fuel cell electrode, they placed a catalytic material, consisting of nanometer scale platinum particles, onto and into a conductive substrate of carbon diatom replicas.
The platinum particles lodged into the fine pores of the carbon replica cell walls, and went on to catalytically outperform standard platinum-loaded carbon black, as well as platinum-loaded carbon derived from silicon carbide.
This superior performance can be traced to the hollow, thin walled 3-D shape derived from the diatoms, Sandhage said.
The oxygen can readily move inside the tiny hollow structure, so it doesn’t have to travel far to reach the platinum buried within the thin cell walls. The result is an electrode with far better performance.
Other potential applications for diatom-derived materials include tiny sensors, fast acting drug delivery capsules, rapid water or synthetic chemical purification, anti-counterfeiting, and hierarchically patterned electrodes for other energy devices.
“Someday, it may become possible to genetically modify the diatom and basically dial in the 3-D shape that we want, which would then allow us to tailor the shape as well as the chemistry for a particular application,” Sandhage said.
Mohan Srinivasarao, a professor in the School of Materials Science and Engineering, wants to understand how the outer shells of some creatures, such as insects, create unusual optical effects such as iridescent colors. He is also investigating how those structures can be simulated to produce comparable effects.
“We are investigating nature-inspired colors and how to change those colors dynamically,” said Srinivasarao. “There are many biological systems that have liquid crystal-like structures on their bodies, and that lets them create colors by altering the frequency of the incoming light.”
The potential applications of this National Science Foundation-sponsored research are broad, he said. One involves camouflage that would vary with the background. Others might center on long lasting commercial materials that could produce a brilliant color, or a range of shifting colors, using nanostructures rather than dyes.
In explaining nanostructure-based coloring, Srinivasarao pointed to the case of a butterfly that is not green but can make itself appear so.
Green is an excellent color choice for an insect living in foliage, but it’s also a difficult color for many creatures to generate in the natural world. The butterfly in question achieves this protective hue by mixing yellow and blue wavelengths together.
In another instance, one type of beetle can produce both green and yellow by depositing chitin, a natural polymer that occurs in its exoskeleton, in the manner of a helix. The pitch of that helix – the width of one complete turn – is about 300 nanometers.
At the same time, the exoskeleton’s index of refraction – a measure of how light propagates through it – is approximately 1.5. The interaction between the pitch, the index of refraction and incoming light simulates the color green.
“There are no dyes, no pigments,” said Srinivasarao. “If you look at the 300-nanometer spacing in between these lines here on the beetle’s shell, that’s on the right order of magnitude to provide the green reflection.”
Vladimir Tsukruk, a professor in the School of Materials Science and Engineering, is studying ways to put organic and inorganic materials together to create new functionality. Specifically, he unites “soft” materials – biologically derived polymers and organics – with “hard” materials such as noble metals and other inorganic structures.
“Our approach involves developing what can be called bioinspired materials – based on examples from nature – that have unusual physical properties,” Tsukruk said. “Soft materials and hard materials have unique sets of properties, but by combining them you can get something much more intriguing.”
Tsukruk and his research team are studying ways to interface such disparate materials so that they function together productively. A host of problems – including clear mismatches in physical properties, molecular structure and other characteristics – make the work challenging, he said.
In one project, Tsukruk is combining genetically modified spider silk – one of the toughest materials in nature – with ultrathin films of graphene oxide to form a layered nanocomposite. By alternating layers of the two materials, 20 percent graphene and 80 percent silk, he aims to unite graphene’s strength with the toughness and elasticity of the silk.
A paper on this work, funded by the Air Force Office of Scientific Research, was published in April 2013 in the journal Advanced Materials. And in another study, recently published in the journal Angewandte Chemie, Tsukruk and a research team demonstrated a method for writing electrically conductive patterns on flexible silk-graphene biopaper.
Silk-graphene nanocomposites can have strength comparable to the best steel and the flexibility of conventional paper, Tsukruk said, while also offering flexibility and lighter weight. Such materials could be mass produced after certain issues are resolved, such as obtaining low-cost silks, which could be manufactured through the use of genetically modified bacteria.
A critical part of materials development involves moving technology from the laboratory to real-world applications. Jud Ready, a principal research engineer in the Georgia Tech Research Institute (GTRI), brings nanomaterials discoveries to bear on a variety of energy-related and other components, including solar cells, batteries, supercapacitors and field electron emitters.
“We research a variety of different ways to use electrons in a material, with the intention of making a useful device and then hopefully commercializing that device,” he said.
Ready and his team have developed a 3-D photovoltaic technology that uses micron-scale “towers” to capture nearly three times as much light as flat solar cells of the same materials. The technology – aimed at applications such as satellites, cell phones and military equipment where limited surface area is an issue – is now licensed to California-based Bloo Solar Inc.
The research team is presently readying another solar cell technology that could lower costs while maintaining a useful level of performance. Under this approach, the low-cost elements copper, zinc, tin and sulfur (CZTS) replace more costly elements – copper, indium, gallium and selenium (CIGS) – that have been used in photovoltaics.
“CZTS materials are virtually identical in crystal structure and manufacturing approaches to CIGS, which costs at least a thousand times more,” Ready said. “So even if CZTS efficiency is only 15 percent versus some 20 percent for CIGS, the CZTS raw material costs a penny as opposed to $10 for CIGS.”
GTRI’s CZTS technology is expected to be installed and tested on the International Space Station in December 2014. Commercial development of the technology is on the horizon as well; the researchers are working with VentureLab, a startup company incubator for Georgia Tech researchers.
A battery that costs less and lasts significantly longer in laptops, cell phones or electric cars before recharging would be welcome to both consumers and industry. Gleb Yushin, an associate professor in the School of Materials Science and Engineering, is working with battery materials that could outperform the conventional lithium ion technology common today.
Yushin and his research team are studying several chemistries that hold promise for future battery technologies. In addition to ultra-high capacity materials for lithium ion cells, the team is studying magnesium ion and aluminum ion chemistries, which can carry more charge than lithium ions, as well as sodium ion chemistry which may offer reduced cost.
The problem is, the larger the amount of charge on an ion – which is an atom or molecule that carries an electrical charge – the greater the potential barriers within the battery’s charging system. The result is that it presently takes far longer to charge and discharge batteries built around the non-lithium chemistries. The Georgia Tech researchers are working on improving these materials to reach an acceptable rate of charge and discharge.
Yushin also studies supercapacitors, which are energy storage devices that can charge up in seconds and then deliver energy quickly. He has developed composite materials that charge at the same fast rates but store far more energy – a big advantage for applications such as wind farms, certain hybrid vehicles, military activities and others.
“These are difficult problems that require long term study to solve,” Yushin said. “To do this, we are examining the fundamentals of structure and properties at the nanoscale – to learn how the microstructure of these materials and their chemistry can impact the insertion and extraction of different metal ions.”
Yushin is conducting fundamental studies of ion transport to advance his work on batteries and supercapacitors. In collaboration with Oak Ridge National Laboratory scientists, he and his team recently carried out experiments that added to the basic understanding of ion activity.
The researchers used a technique called small angle neutron scattering to directly observe how ions behave in certain microporous materials. By directing a beam of high-energy neutrons on activated carbon electrodes during supercapacitor operation, they determined how electrolyte composition affected the average ion concentrations in pores of different sizes as a function of the applied potential.
“In these experiments we gained unique information about ion adsorption in sub-nanometer pores that nobody else had obtained previously,” Yushin said. “Understanding these processes better could lead to the development of improved energy storage, as well as advances in fields such as water purification, desalination systems and biological systems.”
Faisal Alamgir, an associate professor in the School of Materials Science and Engineering, is tackling research challenges involving energy-related behaviors in applications that include batteries and solar cells.
In battery-related research, Alamgir and his team are studying ways to make lithium ion batteries safer and longer-lasting. Among other things, Alamgir wants to understand and optimize the behavior of various elements within a cycling lithium ion cell.
In one important study sponsored by the National Science Foundation Materials Research Science and Engineering Center, Alamgir has investigated the role of oxygen in the creation of electrons in lithium ion batteries. Among the key issues: whether the oxygen present in battery materials is participating in the electrochemical reaction as lithium cycles in and out. If so, that could help explain why fires have occurred in some large lithium-based batteries.
Alamgir and his team used X-ray absorption spectroscopy to look inside an operating battery. The work confirmed that oxygen is indeed being created under some conditions during the charging and discharging process in a lithium ion battery.
“Now we know that fires may start inside a lithium cell even if there was no puncture in the cell – because there is oxygen participating in the reaction,” Alamgir said. “If we want to make safer batteries, we must work in a voltage range where the oxygen is not as active – which varies with temperature – or we must come up with an alternative cathode material that keeps the oxygen from participating electrochemically.”
In the area of solar cells, Alamgir is examining the use of new materials in dye-sensitized solar cells (DSSCs). This type of solar cell promises lower costs compared to more traditional techniques.
In one approach, he is studying the use of low-cost titanium dioxide instead of conventional silicon as the light-absorbing semiconductor in solar cells. By also adding certain dyes that increase light absorption, he has designed a photo-electrochemical system that could be manufactured more easily and inexpensively than today’s silicon technology.
In other work, Alamgir is looking at materials and methods that could replace or reduce the use of costly platinum, the traditional choice as a counter electrode of DSSCs, as well as electrodes in proton exchange membrane (PEM) fuel cells.
One method seeks to limit platinum’s use to ultra-thin films, consisting of only a few monolayers of the element. Alamgir has shown dimension-dependent transitions in enhancement of properties in platinum when it is restricted to layers that are only a few atoms thick.
In today’s world, there’s a pressing need to find the most energy efficient materials. Seung Soon Jang, an associate professor in the School of Materials Science and Engineering, is using computational modeling to examine the relationship between structure and properties in these materials.
“We perform first principles atomistic modeling, which means we include all the details of a material’s atoms – its hydrogen, carbon, oxygen and others – without simplifying anything,” Jang said. “We can then use that highly detailed knowledge to design new materials.”
Today’s sophisticated observational tools are used by scientists to produce reams of experimental data. Jang and his team in the Computational NanoBio Technology Laboratory utilize these big-data troves to develop useful models of materials behavior at the smallest scales, exploiting powerful computers.
At the atomic scale, Jang and his team use quantum mechanical simulations derived from computational physics and chemistry to understand the distribution of electrons, which give a particular material many of its unique properties. At a slightly larger scale, he employs molecular dynamics simulations to understand how the grouping of molecules also determines a material’s behavior.
Jang is using these techniques to tackle projects in multiple areas including semiconductors, carbon nanotubes and graphene, biomaterials, and fuel cells, batteries and solar cells.
In one recent project sponsored in part by the National Science Foundation and Department of Energy, Jang and several collaborators investigated behavior in semiconductor materials at very small scales. In particular, they studied a phenomenon that takes place when the dimensions of certain semiconducting materials are reduced to nanoscale levels: non-metallic materials unexpectedly take on metallic properties.
In another project, sponsored principally by the Department of Energy and a major automotive company, Jang is studying the performance of polymer membranes in automotive fuel cells. The aim is to find new membrane designs that will improve the material’s performance at extreme temperatures.
Zhiqun Lin, an associate professor in the School of Materials Science and Engineering, is pursuing research on solar energy conversion. To increase solar cell efficiency, he is working with nanostructured functional materials, including conjugated polymers, nanocrystals, and nanocomposites made of conjugated polymers and nanocrystals.
Nanocrystals are nanoparticles with a crystalline structure – meaning their atoms are arranged in a regular, periodic way. In a given material, their crystalline form can give them special behaviors that don’t occur at larger size scales in the same material. Lin has been concentrating on producing functional nanocrystals that will support more-efficient solar cells.
In work funded by the Air Force Office of Scientific Research, Lin recently discovered a simple and robust approach to making a wide variety of functional nanocrystals with controllable sizes, compositions and architectures – including metallic, ferroelectric, magnetic, semiconducting and luminescent nanocrystals. The new technique – described in the June 2013 issue of the journal Nature Nanotechnology – targets nanoparticles for applications where tight control over size and structure promotes desirable properties.
Lin and his team are pursuing several projects involving solar cells. One effort involves hybrid solar cells, so called because they utilize both organic and inorganic semiconductor materials.
In this approach, conjugated organic polymers are coupled with inorganic semiconducting nanocrystals. Incoming photons are absorbed in the polymer, generating electrons that are then injected into the semiconducting nanocrystals to produce current. Advantages include low cost to manufacture and toughness that could facilitate solar cell installation.
In another project, Lin is developing photovoltaic cells using abundant, low cost and environmentally friendly elements: copper, zinc, tin and sulfur. Made into functional nanocrystals that can serve as the semiconductor, these elements could replace expensive noble metals such as platinum, as well as rare earth elements that can be hard to obtain, for use as counter electrodes in high-efficiency dye-sensitized solar cells.
The use of thin films – layers with thicknesses in the nanoscale to micron-scale range – has become increasingly important in a number of technological applications. Samuel Graham, a professor in the Woodruff School of Mechanical Engineering, is focusing on methods for growing thin films, as well as studying their properties and reliability.
Such films can be used in applications that include optical coatings, batteries, solar cells, semiconductors and micro-electromechanical systems (MEMS). In addition, thin films can be used to protect other materials against degradation such as corrosion or harmful reactions with the environment.
One of Graham’s current research goals involves developing defect-free coatings using a method called atomic layer deposition (ALD), which deposits the films in a layer by layer fashion and gives unique control over film thickness and film composition. He is also researching layers that can be used to allow uniform growth of these films using ALD on virtually any material, including plastics, metals and organic electronics.
In work sponsored by the Department of Energy, Graham and his team are collaborating with professor Bernard Kippelen of the School of Electrical and Computer Engineering in the use of ALD to create barrier films that can protect flexible and organic electronics from being degraded by water vapor and oxygen in the ambient environment. They have found that materials including aluminum oxide and titanium oxide perform well in protecting the electronics underneath.
Testing these oxides includes measuring water vapor transport rates through very thin layers to gauge protection levels. Graham and his team are also looking at the use of these oxides in flexible electronics, testing how far these thin films can be bent or stretched before they develop cracks.
“One of the things we have found is that the thicker a film is, the less strain it takes to crack it, so the ultra-thin films are better,” Graham said. “That finding could benefit industry, because putting down a 20-nanometer thick film takes less time and material than producing a 50-nanometer thick film.”
Among other projects, Graham is researching the use of oxide films in the development of novel electrodes for organic electronics. The result could be more efficient and stable electrodes for organic solar cells, which is an emerging technology for future photovoltaic systems.
Antonia Antoniou, an assistant professor in the Woodruff School of Mechanical Engineering, studies the mechanics of materials at the nanoscale. She and her research team are synthesizing and studying metal foams, which are materials with nano-sized pores that behave like tiny sponges. The aim is to assess the unusual mechanical properties of these nanopore formations. Their intricate three-dimensional structure contains a large amount of surface area, along with a granular composition that offers myriad interfaces.
Such foams hold promise for applications including battery electrodes or supercapacitors, catalysts that increase chemical reactions, and tiny sensors.
Antoniou’s techniques enable structures to self-assemble at the nanoscale. She and her team start with a mixture of two or more metal elements, and then selectively use a corrosive environment to dissolve one or more of them. The result is an intricate porous network with special properties.
The researchers test the foams’ mechanical properties using a tiny probe called a nanoindenter. They also use electron microscopes to image the surface and view changes taking place at the nanoscale.
“The rules tend to change when you reach the atomic level,” Antoniou said. “Unlike a bulk alloy, these foams often have gigapascal strength, which is a very high level of strength for a metal and could enable certain challenging applications.”
Antoniou works with a variety of metals, especially platinum, copper and molybdenum. Collaborating with scientists at Georgia Tech and several other universities, she is investigating applying these foams to the needs of several industries.
In one National Science Foundation-sponsored project, the group is studying applications that could be useful to the nuclear industry. The foams’ innate strength lets them tolerate a significant amount of radiation, suggesting potential applications such as protective coatings.
“It’s important to remember that successful applications are based on understanding these materials at a fundamental level,” she said. “By synthesizing them, we exercise control over the structure, and then by testing them, we can discover unique behaviors.”
Nazanin Bassiri-Gharb, an assistant professor in the Woodruff School of Mechanical Engineering, focuses her research on thin films and nanostructures made with ferroelectric materials – which have a spontaneous electric polarization that can be reversed by applying an external electric field.
“We call ferroelectrics smart materials, because they react to many different external fields – not only mechanical but also electrical and thermal – and they lend themselves to many applications including sensors, actuators and energy harvesting,” said Bassiri-Gharb, who has a joint appointment in the School of Materials Science and Engineering. “My group is specifically trying to understand the fundamental behavior of ferroelectric materials at the very small scale.”
Bassiri-Gharb and her research team are pursuing multiple research projects related to ferroelectrics. They’re working extensively on electromechanical response in piezoelectric materials, which produce a charge when mechanically stimulated. In a Small Business Innovation Research (SBIR) project funded by the Air Force, Bassiri-Gharb is working with a company to develop large-scale production of ferroelectric nanotubes to harvest energy from human stepping motion. The challenge is to distribute the material in a network of piezoelectric islands rather than in one piece. That configuration creates pathways that allow the maximized amount of the generated electric charge to flow to collection points such as batteries or capacitors.
In a collaborative project with Oak Ridge National Laboratory, Bassiri-Gharb and her team are working on understanding multiscale coupling of mechanical, electrical and chemical properties in oxide thin films – specifically as it applies to miniaturization of energy technologies including multilayer capacitors, batteries, and fuel cell devices.
“We’ve learned a great deal from this work, including the interaction between the piezoelectric thin film and its inactive silicon substrate” she said. “Our research shows that as we drastically reduce the thickness of the silicon, the piezoelectric response gets much larger.”
Understanding how materials function at the smallest scales is key to modern materials science and engineering. David Bucknall, a professor in the School of Materials Science and Engineering, uses advanced techniques – including neutron scattering and X-ray scattering – to characterize polymers at the atomic and molecular levels.
“Using these scattering techniques, we can probe a material in situ – meaning in an application-related environment – allowing us to observe structural changes that occur during use or operation of the material,” he said. “By applying a number of complementary techniques, this allows us build up a three-dimensional understanding of the structure and gives us a picture of the complex interplay between a material’s microstructure and its efficiency or its robustness in a device.”
In the field of organic electronics, Bucknall and his team are working with colleagues in the Center for Organic Photonics and Electronics (COPE) to manipulate molecular-level surface interactions to achieve increased efficiency in organic photovoltaic materials. Neutron scattering is extremely useful in this Department of Energy-funded research, Bucknall said, because it provides one of the few methods to differentiate between the active materials in the organic photovoltaic devices, allowing determination of the interaction between the constituent materials.
Understanding this interaction between the materials allows COPE scientists to adjust the chemistry and synthesize new variations. The aim of the work is to build organic photovoltaic devices with much higher efficiencies than currently available.
Bucknall is also using X-ray scattering and neutron scattering techniques to characterize fracture and deformation mechanisms in polymer structures. In one project, he is working with a major energy company to determine the molecular origin of tear and puncture resistance in polyethylene.
In a related project, he is collaborating on a study of very high rate deformation of polymers with professor Naresh Thadhani, chair of the School of Materials Science and Engineering. The work involves propelling different polymeric materials at very high velocities at a solid block of steel and then recording the resulting shape changes in real time using high-speed imaging, spectroscopy, and interferometry techniques.
This work, Bucknall said, could lead to a deeper fundamental understanding of deformation in other polymers, such as those used in automotive vehicles and increasingly in aircraft.
The more accurately researchers can analyze a material’s structure at multiple scales – from the nanoscale to the micron scale and larger – the more fully they can explain that material’s properties and performance.
Understanding this complex relationship is a challenge. Arun Gokhale, a professor in the School of Materials Science and Engineering, uses mathematics and computer simulations to tackle such problems.
“My research focuses on how we mathematically represent a structure, how we simulate it, and how we bring that simulation into a model that explains the structure’s properties,” he said. “The microstructure of a material is almost always three-dimensional, and how those particles are distributed – how many are there, what is their size, what is their shape – dictates how it will behave.”
In one common approach, researchers obtain structural data by capturing multiple images of a microstructure. They sequentially remove very thin layers, imaging each with electron microscopes or other techniques.
This procedure produces an entire stack of sections, making possible a 3-D representation of the structure that reveals every particle, chain and cluster. By bringing geometrical and statistical processing to bear on this information, Gokhale and his team produce a features library – a mathematical description of the patterns that comprise a particular material.
The research team then uses this information to generate a computer simulation that closely represents the actual material. Using the simulation, researchers can vary the material parameters individually, allowing them to create virtual models of potential new materials.
“We can take these virtual materials, apply stress to them and see how they behave in different applications,” Gokhale said. “Simulations will never give you the exact answer – but you can narrow down the possibilities substantially.”
Gokhale has used this type of approach in multiple projects, including Department of Energy-funded research to design lighter weight vehicle components.
In materials, the secret to obtaining desirable properties often lies in understanding the extreme details. Elsa Reichmanis, a professor in the School of Chemical and Biomolecular Engineering, is working to improve the performance of organic materials by understanding the complex relationship between how they’re made and how they perform in a device.
Organic polymers – a type of plastic – offer promise as flexible, lightweight semiconductors for applications that include solar cells, sensors, displays and other electronics. For one thing, organic polymers offer the potential for lower materials costs and for less expensive and demanding manufacturing processes.
With research funding from the National Science Foundation and the U.S. Air Force, Reichmanis and her research team are studying various organic polymers – amorphous, crystalline and semi-crystalline – to understand their microstructures. The researchers are seeking to identify how each material’s structure, process and device performance attributes correlate.
“We want to be able to more rationally design materials for a particular application,” Reichmanis said. “We’re also trying to build a knowledge base of fundamental insights that can be used to develop better materials and processes.”
To achieve this, Reichmanis and her team synthesize an organic polymer material in the lab, and then characterize its microstructure at the nanoscale. Finally, they prepare tiny lab-scale devices, 50 to 100 microns in size, by applying a thin film of an organic polymer to a silicon substrate. This configuration is used for testing purposes – an actual production device would likely be made entirely of organic polymers.
The team analyzes the complete material, from nanostructure to macrostructure, to understand how all the components work together, she explained. Microstructure regions tend to vary considerably, affecting performance; in some regions molecules will line up in desirable ways, others will be amorphous, and still others will form a complex mix.
“If we want a viable commercial technology, we have to be able to repeat – controllably and on a large scale – the microstructure that we want,” she said. “Only by understanding the fundamental side of things can we really affect control on the manufacturing side.”
Christopher W. Jones is studying carbon dioxide capture, a technology with obvious potential as CO2 builds up in Earth’s atmosphere.
Jones, who is the New-Vision Professor in the School of Chemical and Biomolecular Engineering (ChBE) and Georgia Tech’s associate vice president for research, is collaborating on the challenge of carbon dioxide with several ChBE faculty: assistant professor Ryan Lively; assistant professor Yoshiaki Kawajiri; professor William Koros, Roberto C. Goizueta Chair for Excellence in Chemical Engineering; professor and David Wang Sr. Fellow Matthew Realff, and professor David Sholl, Michael E. Tennenbaum Family Chair and a Georgia Research Alliance Eminent Scholar for Energy Sustainability.
The group is working on methods by which carbon dioxide, the principal agent in climate change, can be separated from other gases and prevented from being released into the atmosphere. Together, they are working on new techniques for capturing concentrated CO2 at major sources, such as coal and natural gas fired power plants.
In collaboration with Sholl, Jones is researching an even more challenging approach that involves pulling CO2 from ambient air anywhere on the planet. Georgia Tech is a leader in this technology, which could be useful environmentally, commercially and even tactically, said Jones, who is also an adjunct professor in the School of Chemistry and Biochemistry.
“We have developed a process that can capture CO2 anywhere – and do it almost as effectively as if we were capturing it at the flue of a power plant, where it’s 300 times more concentrated,” he said. “From a climate change perspective, this allows addressing CO2 from all sources – cars, trucks, planes – anywhere it’s being produced. In addition, the military could use it as a carbon source to make synthetic fuels in the field.”
The approach used by Jones and the team is based on the use of solid oxides functionalized with amines, which are strongly basic organic compounds that bind to carbon dioxide. Georgia Tech research has shown that varying the nature of these amines on the surface of an oxide produces new materials with tunable CO2 adsorption behavior.
A company called Global Themostat LLC has licensed some of these research findings, Jones said. The company is working with Georgia Tech on scaling up the process at a pilot plant in California.
Jones and a research team are also engineering catalytic materials with important potential uses in the production of energy-related products and other chemicals. In one effort, Jones is developing solid catalysts capable of making bulk chemicals like ethanol and 1-propanol at lower costs. In another study, he is working on enantioselective catalytic reactions to enable production of specialty organic chemicals or pharmaceuticals.
For decades, transistors used in electronic devices have been growing ever smaller. Yet the amount of energy they demand has remained high – a fact obvious to anyone who’s worked with a hot laptop computer.
Eric Vogel, a professor in the School of Materials Science and Engineering, is working on a project that would help lower that energy need.
“As we move forward, the problem with silicon technology is not performance – we could actually get much more performance out of the transistors we have now,” said Vogel, who is also an adjunct professor in the School of Electrical and Computer Engineering. “The big problem is the amount of energy they need, so we’re focusing on new materials that would offer similar performance with much lower energy consumption.”
Vogel and his team are working within the Center for Low Energy Systems Technology (LEaST), one of six centers supported by STARnet, a Semiconductor Research Corp. program sponsored by the Microelectronics Advanced Research Corp. (MARCO) and DARPA.
The researchers are tackling the energy issue utilizing a variant of graphene technology. They’re using chemical vapor deposition to grow multiple thin layers of current-carrying graphene, separated by energy barriers, on a substrate.
This approach takes advantage of a technique called resonant tunneling of carriers to increase electron flow. Under this quantum mechanical concept, the wave-like behavior of an electron allows it to move readily through an energy barrier and appear on the other side in the next graphene layer. The result is increased efficiency in the energy-carrying electron flow.
Vogel and his team are working on the materials challenges involved in making these types of devices. An important issue centers on the role of the dielectric layer – the energy barrier – and how it affects electron tunneling.
One challenge involves the metal oxides used as dielectric layers, because they have defects that can hamper electron tunneling. The researchers have discovered that thinning a dielectric layer to one nanometer eliminates the tunneling difficulties.
The team is currently investigating why this happens, Vogel said. Understanding this phenomenon in depth could bring these graphene-based materials closer to real world use.
Building on basic research strengths in the materials domain, researchers at Georgia Tech are developing an innovation ecosystem that serves to translate transformative technologies into real world applications. Aligning with federal efforts such as the Materials Genome Initiative and the Advanced Manufacturing Partnership, Georgia Tech is continuing to establish productive and mutually beneficial relationships with government and industry.
John Toon also contributed to this article.
Formed by four faculty members in 2003, the Center for Organic Photonics and Electronics(COPE) performs research in a challenging but promising field: the use of organic materials to build photonic and electronic devices. These lightweight, low-cost plastics represent a new direction for a field dominated by devices based on silicon and a few other inorganic materials.
Today, COPE includes 36 Georgia Tech faculty members from seven different schools in a highly interdisciplinary approach to research, innovation and student training. Nearly 150 graduate students, undergraduates and postdoctoral researchers also work within COPE.
The center has extensive shared facilities for computing, chemical synthesis and materials characterization, along with device fabrication and testing. COPE has attracted more than $66 million in funding since its start; sponsors include the National Science Foundation, Department of Energy, Department of Agriculture, several Department of Defense agencies, the King Abdullah University of Science and Technology, the international chemical group Solvay, and numerous others.
“Once you can develop and validate organic semiconductors, you can build any solid-state device that could be made traditionally with inorganic semiconductors,” said Bernard Kippelen, a professor in the School of Electrical and Computer Engineering who is COPE’s director. “But to do all this, you need expertise that goes beyond the conventional disciplines of chemistry or physics or material science or electrical engineering.”
That, he added, is why COPE was interdisciplinary from the start. A physicist by training, Kippelen helped found the center along with three chemists – Jean-Luc Brédas, Seth Marder and Joseph Perry – who are professors in the School of Chemistry and Biochemistry. Today, COPE researchers are among the leaders in developing novel organic materials for 3-D microfabrication, photonic computing, solar cells and other applications.
Kippelen is also president of the Lafayette Institute at Georgia Tech-Lorraine in Metz, France. The Lafayette Institute, which benefits from 31 million Euros in financing from the French government, provides new opportunities for COPE in Europe due to its focus on technologies at the intersection of materials, optics, photonics, electronics and nanotechnology.
“At this point COPE, through its many different interactions, is literally part of a global network,” said Marder, a Regents’ Professor who was the center’s founding director and is now associate director. “That gives us not only a process for productive collaboration worldwide, it also provides a rich opportunity for my students to get real-world training that prepares them for a future in which research is becoming more and more interdisciplinary.”
The physical advantages of organic devices include light weight, flexibility, and puncture and shatter resistance. The manufacturing advantages include low cost; unlike conventional semiconductors, organic thin films can be processed at room temperature onto a variety of common materials using conventional large area coating and printing technologies.
When light in the form of intense laser pulses hits certain materials, it produces a range of nonlinear effects. Marder and Perry, collaborating with Brédas and Kippelen, study ways to use nonlinear optical properties to fabricate novel three-dimensional structures at the nanoscale, and also to use those materials to pursue novel applications.
In one line of investigation, they’re collaborating with research teams from Georgia Tech and other universities to study how novel materials can advance photonic computing, a technology that uses light – photons – for interconnects and some all-optical computing functions. The aim is photonic computing capabilities that could offer greatly increased speed and bandwidth, along with much lower power consumption.
Professor John Reynolds, who recently joined the School of Chemistry and Biochemistry, the School of Materials Science and Engineering, and COPE, has developed a family of polymers that are electrochromic – electrically color-changing. A thin film of these plastics can be printed or sprayed onto a substrate, such as conductive glass or plastic; applying an electrical charge can then switch them instantly from clear to a specific color. The voltage of the applied charge dictates the color intensity.
Unlike other electrochromic techniques, this technology offers memory. That means the color remains when the charge is turned off, saving power. In addition, Reynolds’ technology is unique in offering any color needed, and has been licensed by the BASF Corp.
The Georgia Tech Institute for Materials (IMat) was launched with one core mission: to foster materials-related research throughout the campus. Its June 2013 announcement came exactly two years after the White House launched its Materials Genome Initiative for Global Competitiveness.
The Materials Genome aids U.S. economic development by providing training and infrastructure to help U.S. innovators discover, develop and deploy advanced materials more quickly. The Georgia Tech move supports President Barack Obama’s call for faster movement of advanced materials from laboratory to application.
“Traditionally, it’s taken about 15 years to get a new materials discovery into an advanced product, but it only takes 18 to 36 months to design that new product on computers,” said David McDowell, IMat’s executive director and a Regents’ Professor in the Woodruff School of Mechanical Engineering. “There’s a big disconnect there, and we need to integrate materials design and development much more tightly with new product development.”
IMat is focusing on collaborative, interdisciplinary linkages to achieve new levels of cooperation. Its job involves linking materials-related research within Georgia Tech’s academic units and the Georgia Tech Research Institute (GTRI) to industry, government and academic research laboratories across the nation.
Through this collaborative network, IMat connects the expertise of investigative teams at Georgia Tech with the materials community outside, to help move research advances forward more rapidly. At the same time, it seeks to build bridges between Georgia Tech materials research and important application areas such as energy, manufacturing, nanotechnology, bioengineering and the biosciences.
IMat is one of nine Interdisciplinary Research Institutes (IRIs) under the leadership of Georgia Tech’s Executive Vice President for Research, Stephen E. Cross. Each IRI spans Georgia Tech units to bring together researchers working in a core area. In addition, the IRIs help government and industry navigate Georgia Tech’s myriad activities and connect with researchers, students and laboratory capabilities.
“The benefits of materials-based advances over the last 20 years are now a part of our everyday lives – lifesaving medical technologies, the computers and phones we can’t live without, our more efficient and safer vehicles, and much more,” said McDowell. “Materials research both discovers new materials and uses existing materials in new and enhanced ways. Our continued growth in a competitive global economy depends on performing effectively in these research areas and then applying those insights to real-world applications.”
The Georgia Tech Materials Research Science and Engineering Center (MRSEC) studies primarily epitaxial graphene, a carbon-based material that can be grown in sheets as little as one atom thick. Because it’s an excellent electrical conductor, graphene promises advances in electronics technology. If its speed potential were realized, it could facilitate new and demanding computing applications. MRSEC launched in September 2008 thanks to a six-year, $8.1 million grant from the National Science Foundation. Georgia Tech leads the center, collaborating with the University of California-Riverside, University of Michigan and several European research teams.
“Silicon has fundamental limitations in its material properties that restrict its performance,” said MRSEC director Dennis Hess, who holds the Thomas C. DeLoach Jr. Chair in the School of Chemical and Biomolecular Engineering. “Silicon will always be around in basic devices, but for high-speed devices we either have to change the type of device we make or come up with a new material – and graphene is a contender for that role.”
At Georgia Tech, Hess explained, graphene research started in 2001 when Regents’ Professor Walt de Heer of the School of Physics determined that there might be better ways to make electronic devices than using cylindrical carbon nanotubes. As a result, de Heer, who directs MRSEC’s graphene interdisciplinary research group, turned to epitaxial graphene.
In principle, an electron can move in graphene 100,000 times faster than in silicon, making possible much higher speed devices, Hess said. In practice, attempts to achieve these electron speeds in a functional graphene device have been problematic.
De Heer has successfully pioneered methods for producing high-quality layers of epitaxial graphene on the surface of silicon carbide wafers. In addition, his technique for fabricating nanoribbons of epitaxial graphene has produced structures just 15 to 40 nanometers wide that conduct current with little resistance – offering the possibility of very high electrical performance.
But challenges remain, Hess said. They include devising methods for connecting graphene devices with conventional computing architectures, including how to incorporate contacts and dielectrics into such devices, how to input and output current, and how to generate patterns in the material.
“The fact is, if graphene can be successfully developed as a device platform, it should produce major advances in computing capability,” Hess said.
Zinc oxide, a familiar material used in plastics, paints, ointments, foods and many other things, can play significantly different roles at the nanoscale. A Georgia Tech research team led by Zhong Lin Wang, a Regents’ Professor and Hightower Chair in the School of Materials Science and Engineering, uses the unique properties of zinc oxide nanostructures to generate electrical energy that can power and control electronic devices.
Wang uses nanostructures to create a piezoelectric effect. In piezoelectrics, electrical energy is produced when charge-producing structures – in this case zinc oxide nanowires – are strained or flexed by some mechanical action, even a very minor one. The action can take the form of motion from many overlooked sources, such as the flow of fluids in the human body, vibration or the flexing of fabric in a shirt.
Wang and his research group have been studying zinc oxide nanostructures since 1999. They have increased the piezoelectric output from zinc oxide nanogenerators from negligible amounts to as much as 50 volts using sophisticated engineering design.
The researchers have also developed the field of piezotronics, which uses piezoelectric properties of zinc oxide nanostructures to control charge transport in an electronic device such as a semiconductor, offering an alternative to traditional CMOS technology.
Wang has also coined the term “piezo-phototronics” to describe techniques for using zinc oxide-based nanotechnology to control electro-optical processes in such devices as light-emitting diodes (LEDs) and solar cells to produce enhanced performance.
“People have never really harnessed this energy before, but its potential can be tremendous,” said Wang, a physicist by training. “Using these nanotechnologies, it is possible to have self-powered, maintenance-free biosensors, environmental sensors, nanorobotics, micro-electromechanical systems, and even portable and wearable electronics.”
Among the energy-harvesting strategies that Wang and his team have developed are running shoes that use a polymer based nanogenerator to create a charge as the user moves. He’s also built a “power shirt” that produces energy as the wearer moves, and he has employed piezo-phototronic technology to boost the performance of LEDs.
Wang and his team have developed a sensor device that uses nanowires to convert mechanical pressure – from a signature or a fingerprint – directly into light signals that can be captured and processed optically. The research was reported in the journal Nature Photonics.
Beyond collecting signatures and fingerprints, the technique could also be used in biological imaging and micro-electromechanical (MEMS) systems. Ultimately, it could provide a new approach for human-machine interfaces.
Again using nanowires, the researchers have fabricated arrays of piezotronic transistors capable of converting mechanical motion directly into electronic controlling signals. The arrays could help give robots a more adaptive sense by making artificial skin smarter and more like human skin, allowing the skin to feel activity on the surface. The research was reported in the journal Science.
The arrays include more than 8,000 functioning piezotronic transistors, each of which can independently produce an electronic controlling signal when placed under mechanical strain. These touch-sensitive transistors – dubbed “taxels” – have sensitivity comparable to that of a human fingertip.
Branching out from zinc oxide, Wang and his team recently discovered yet another way to harvest small amounts of electricity from motion. They can now capture the electrical charge produced when two different kinds of plastic materials rub against one another.
Based on flexible polymer materials, this “triboelectric” generator could provide current from activities such as walking, offering an alternative to nanogenerators that produce current from flexing nanowires. An energy conversion efficiency of around 50 percent, providing output power density of 300 watts per square meter and 400 kilowatts per cubic meter, has been demonstrated, with the potential to harvest energy from body motion, engine vibration, wind, flowing water, raindrops and even ocean waves. Details of the discovery were reported in the journal Nano Letters.
Triboelectric generators can be made nearly transparent, so they could offer a new way to produce active sensors that might replace technology now used for touch-sensitive device displays.
Georgia Tech researchers have been working to help bridges and other coastal structures last longer, making them safer and less costly to maintain. Faculty from the School of Civil and Environmental Engineering (CEE) and the School of Materials Science and Engineering (MSE) have collaborated to develop a more robust design for a pile – a large post-like component used to support structures in water.
The goal is an improved design that could be applied to any concrete-and-steel structure that supports bridges, piers and the like. The work, sponsored by the Georgia Department of Transportation, is aimed at finding approaches that conform to a new state of Georgia directive requiring bridges and other infrastructure to last for 100 years, rather than the 40 to 50 years common today.
At a location on the Georgia coast near Savannah, a team including CEE professors Lawrence Kahn and Kimberly Kurtis and MSE professor Preet Singh examined concrete piles that had been in service for 37 years. The object was to pinpoint which environmental factors played the biggest role in the deterioration of the steel-reinforced structures.
The research team, which included several graduate students, studied what happened to the piles in the corrosive conditions like those along the seacoast.
“We saw damage that wasn’t surprising in a coastal environment, such as extensive corrosion,” Kurtis said. “But we also encountered unexpected factors, such as destruction to the piles due to attack by sulfate ions and by species of sponges that consume certain portions of the concrete.”
Working with industrial companies in Georgia and Tennessee, the team has developed a novel pile design. They’re using a more environmentally resistant type of high-performance marine concrete, which is reinforced using stainless steel rather than rust-prone carbon steel.
Singh, a corrosion expert, selected the most promising type of stainless steel from hundreds of available varieties. In a novel design move, he chose duplex-grade stainless steel for the pile’s pre-stressing strand.
The new pile formula being field-tested to measure its resistance to environmental deterioration. If successful, the design could become standard in the construction of bridges and other infrastructure throughout Georgia and elsewhere.
Research projects mentioned in this article are supported by sponsors that include the National Science Foundation (NSF), Office of Naval Research (ONR), Department of Energy (DOE), Department of Homeland Security (DHS), U.S. Air Force (USAF), Air Force Office of Scientific Research (AFOSR), U.S. Army (USA), Army Research Office (ARO), Oak Ridge National Laboratory (ORNL), Defense Threat Reduction Agency (DTRA) and the Defense Advanced Research Projects Agency (DARPA). Any opinions, findings, conclusions or recommendations expressed in this publication are those of the principal investigators and do not necessarily reflect the views of the NSF, ONR, DOE, DHS, USAF, AFOSR, USA, ARO, ORNL, DTRA or DARPA.
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]]>Ayanna Howard has a heart for children with disabilities. So when a National Science Foundation grant led to development of an input device that would allow kids with disabilities to operate tablet computers, she wanted to commercialize the technology to get it into the hands of the children.
But after talking with more than a hundred potential users of the device, she learned the real need was for a generic interface system able to connect a wide range of input devices – big button switches, joysticks, sip-and-puff straws and others – to the tablet computers. And it turned out that the market was much larger than Howard imagined, extending to adults with disabilities and potentially even persons with Alzheimer’s.
A professor in the Georgia Tech School of Electrical and Computer Engineering, Howard has now launched a company, Zyrobotics, to commercialize the device, and a prototype has already been developed. The company, run by a former graduate student, won’t be the next IBM, but it will help disabled children do what all kids want to do: play video games and interact with computers.
Assistance with refining the device came through the Innovation Corps (I-Corps™), a National Science Foundation program that helps NSF-funded researchers learn about starting up a company – and by talking to potential customers, determine whether there’s really a market for what they’ve developed.
“Without I-Corps, I wouldn’t have thought to pursue this,” said Howard, who holds the title of Motorola Foundation Professor. “They showed us how to talk about the technology in terms that the general public could understand. And I-Corps made us take a step back and ask if what we had developed was really of value to potential customers.”
A dozen Georgia Tech teams – each composed of a faculty member, entrepreneurial lead and industry mentor – have now gone through the six-week I-Corps program. About a third of them have, like Howard, revised their plans and decided to move forward with forming a company and creating a product based on the results of NSF-supported research. The program is part of a national effort to turn research discoveries into new companies and new products, supporting economic development and building understanding of what it means to be an entrepreneur.
“Through the Innovation Corps, NSF seeks to accelerate the development of new technologies, products and processes that arise from fundamental research,” said Rathindra (Babu) DasGupta, the NSF’s program director for I-Corps. “The goals of I-Corps are to spur translation of fundamental research, to encourage collaboration between academia and industry, and to train students to understand innovation and entrepreneurship.”
The program provides mentoring and funding designed to move the results of NSF-supported research through the early stages of company formation. “NSF investments strategically strengthen the nation’s innovation ecosystem by addressing the challenges inherent in the early stages of the innovation process,” DasGupta added.
Because of its long experience with forming companies from university research, in July 2012 Georgia Tech was selected to be among the first institutions to become ”nodes” teaching the I-Corps curriculum. The program is basically a boot camp that shows what it’s like to form a startup company – and ensures that there’s a real market for a fledgling company’s proposed product. About 25 teams from universities around the country participate each time the program is taught at one of the I-Corps nodes, including Georgia Tech.
“The I-Corps process is very similar to the scientific method, which scientists and engineers are familiar with,” explained Keith McGreggor, who directs the I-Corps program at Georgia Tech. “We use this process to turn fiction – what you might think is true – into fact by doing experiments and testing hypotheses in the real world with customers instead of in the laboratory.”
I-Corps puts faculty members and graduate students through a pressure cooker environment that simulates a real startup. Not everyone is cut out for entrepreneurship, McGreggor noted. Faculty members often have a skill set – collaborating with other researchers, teaching students and publishing papers – that’s different from the skills needed to produce products and services that non-researchers are willing to buy.
The centerpiece of the program is “customer discovery” in which the teams must talk with at least 100 potential customers about their proposed product. This interaction with the real world almost inevitably leads to what I-Corps calls “the pivot,” which occurs when the teams, based on the customer feedback, realize they’ve been developing a product for which there isn’t a market. In many cases, that realization leads to new, and successful, directions for the technology.
“Everyone starts out with one idea about what they want to do, and they almost always change to something else that they are also capable of doing,” McGreggor said. “It can be difficult for people to switch gears, but what’s beautiful about this program is that they do switch.”
At the end of the six weeks, the teams decide whether or not to go forward with their idea. For Georgia Tech teams, fledgling companies that emerge from the process can join VentureLab, a program that helps researchers form companies, create prototypes, bring in experienced management and obtain early-stage funding. VentureLab companies can go on to be members of the Advanced Technology Development Center (ATDC), Georgia Tech’s accelerator program that helps entrepreneurs launch and build successful companies.
Krista Walton and David Sholl used the I-Corps process to confirm the market need for metal-organic frameworks (MOFs), a new materials technology with a broad range of potential market applications. With NSF support, the researchers had developed a way to scale up the synthesis of MOFs, a class of nanomaterials, but weren’t sure what direction to take next – a classic problem for technologies that have many possible applications.
“By talking with more than 100 potential customers, we went through numerous refinements in our understanding of how we can create a sustainable business with our technology,” said Sholl, who is now chair of Georgia Tech’s School of Chemical and Biomolecular Engineering. “We saw over and over again that the issues that obsess researchers doing fundamental research and the issues that matter to customers are often not the same.”
Talking with the customers required a large investment of time, but Sholl – who is also a Georgia Research Alliance Eminent Scholar in Energy Sustainability – was pleased with the level of interest in the technology. The potential customers he and Walton interviewed also identified applications they had never considered.
As a result of the process, Sholl and Walton – an associate professor in the School of Chemical and Biomolecular Engineering – formed Inmondo Tech, and are working with several initial customers to develop a first product.
For Gregory Abowd, the benefits of I-Corps were different. A serial entrepreneur with a record of launching successful companies, Abowd felt he knew how to commercialize technology he developed that helps connect young patients with their doctors through handheld devices. But he wanted to apply I-Corps’ systematic process to starting up a new company.
“I’ve had some successful and unsuccessful startup efforts, but I really didn’t understand what were the important elements of the successful ones,” said Abowd, who is a Regents’ and Distinguished Professor in Georgia Tech’s School of Interactive Computing. “I was intrigued with the idea of being a little more structured going into this one, because I had learned there are an infinite number of ways to make mistakes in the business world.”
The company, established as L.S.Q. LLC in Georgia, will provide a way to ask questions of smartphone users at times when they aren’t actively using their handheld devices. Building on the original purpose of the technology, which was to boost interaction with children who have chronic diseases, Abowd sees many possible applications, including surveys designed for the small screens of mobile devices.
“We’ll ask questions at a point when people are interacting with their phones, but at a point of pause,” he explained. Abowd has assembled a team and is talking with potential customers. He expects to form a joint venture with a market research firm in early 2014 and develop a product quickly.
What advice do the teams give faculty members and graduate students thinking about the I-Corps opportunity?
“There is a growing network to help with commercialization, both at Georgia Tech and around the country,” noted Abowd. “A successful startup requires a lot of effort, and it’s more than a full-time job. I-Corps gives you a six-week exposure to help you determine whether this is right for you.”
I-Corps requires a large investment of time, something that can be difficult if faculty members aren’t prepared for it, Howard noted. To be successful, at least one member of the team has to be available nearly full-time during the six-week program.
“I would recommend this 100 percent, and have already talked with other faculty members about I-Corps,” she said. “This process is very different from what we normally do in research and teaching, and it has changed the way I think about what I do. It was a great experience for us.”
I-Corps teams follow a rigorous application process designed to determine whether team members are truly committed to launching and building a startup, McGreggor noted. That can be daunting.
“I-Corps simulates a startup, so it puts a lot of heat on the team to see if they are going to stay together when they get into a company,” he said. “We challenge the researchers in ways that they have probably not been challenged since they were graduate students. It is exquisitely uncomfortable for some people.”
I-Corps has also changed the way that Georgia Tech approaches startup companies. Customer discovery and early pivoting to serve the marketplace, for instance, are now at the core of Georgia Tech’s VentureLab and Flashpoint programs, which serve all researchers regardless of their funding sources, McGreggor said.
“Faculty members are forced to look into the face of a world that may not want what they have produced,” McGreggor said. “What we’ve learned is that when entrepreneurs get it wrong, it’s usually because they are building something that nobody really wants. This has really changed our approach to doing things in VentureLab.”
The I-Corps approach has also changed the role of graduate students in the startup process, and opened it more to junior faculty members. In the past, VentureLab had assumed that only tenured faculty would have the time and flexibility to commit to a startup. Now, he says, the program makes no distinction among researchers, and realizes that the graduate students involved in developing a technology may be the right team members to go forward as part of the new company. That makes creating a startup a real alternative to traditional post-graduation opportunities.
Beyond the new enterprises begun, the I-Corps program is having a larger impact on the universities whose faculty members have participated.
“Additional successes of the program have been far-reaching,” said the NSF’s DasGupta. “Faculty are taking what they learned in I-Corps about innovation and technology transfer back to their universities and training their students differently. The participation of students and post-docs in I-Corps has also had favorable impacts: they report that their employability is enhanced by their participating in I-Corps.”
The program was launched in 2011, and continues to evolve as NSF tracks the results. In addition to its teams of researchers, entrepreneurs and mentors, I-Corps is also focusing on nodes and sites to bring the concepts to a larger group of NSF researchers.
“We continue to explore ways to expand the program’s impact nationally, and at the state and local levels,” DasGupta added.
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]]>In his new post, Brand leads an IRI that unites a wide range of faculty, research centers and shared-user laboratories working in the complementary fields of electronics and nanotechnology. This combination of infrastructure and interdisciplinary research activity seeks to fortify Georgia Tech’s expertise in microsystems, advanced semiconductors, photonics and photovoltaics, electronics design, microelectronics packaging, and systems integration, while stimulating new and emerging application areas in biomedicine, energy, and nanomaterials.
"I view my most important task as that of enabling our faculty – maximizing their research involvement opportunities and prospects," said Brand, who was awarded the executive position after a nationwide search. "IEN's job is to help enhance interdisciplinary research at Georgia Tech, and at the same time promote industry-sponsored projects that offer opportunities to develop applications and products in electronics, nanotechnology and related fields, while accelerating new discoveries into the marketplace."
Interdisciplinary research institutes (IRIs) are inclusive units that help connect and support Georgia Tech's 200-plus research centers and laboratories. They extend across college, department and laboratory boundaries to help faculty and staff work with both industry and government on basic and applied research programs. IRIs provide critical research infrastructure, create and utilize novel research laboratories, interact with students, and collaborate with other research partners including corporations, universities and research institutes.
Each IRI is dedicated to one of Georgia Tech’s core research areas. Besides electronics and nanotechnology, Georgia Tech IRIs focus on bioengineering and bioscience; energy and sustainable infrastructure; manufacturing, trade and logistics; materials; national security; people and technology; renewable bioproducts; and robotics (see www.research.gatech.edu/institutes).
"In addition to promoting collaboration and new research, I believe IEN should be forward-looking and help define future research grand challenges," Brand said. "On the one hand, we need to react quickly and effectively to requests for research proposals coming in to us, and on the other hand, we need to be proactive by seeding concepts that can be used to generate future calls for proposals."
Brand received his Ph.D. from ETH Zurich in Switzerland in 1994. He did postdoctoral research at Georgia Tech from 1995-1997, and then returned to ETH Zurich as a lecturer and deputy director of its Physical Electronics Laboratory. He came back to Georgia Tech in 2003 as a faculty member in the School of Electrical and Computer Engineering, gaining tenure in 2007 and becoming a full professor in 2009.
"Professor Brand is committed to seeding and growing new interdisciplinary and industry-sponsored research efforts and working closely with faculty and sponsors to define an electronics and nanotechnology roadmap for the future," said Stephen E. Cross, Georgia Tech’s executive vice president for research. "In addition, he is wholeheartedly dedicated to positioning Georgia Tech as the home of the nation’s leading electronics and nanotechnology thought leaders."
As IEN's executive director, Brand oversees some 60 staff members, and shared-user research facilities that include two major buildings and more than 200 micro/nanoelectronic fabrication and characterization tools in multiple cleanrooms and laboratories (see www.ien.gatech.edu). The IEN and its associated research centers support the work of more than 200 faculty members from 10 academic schools, as well as the Georgia Tech Research Institute (GTRI).
Brand's own area of research focuses on micro-electromechanical systems, or MEMS. MEMS is a complex field that spans a number of traditional engineering disciplines including mechanical engineering, electrical engineering and chemical engineering, along with physics and chemistry. This interdisciplinary work, he said, helps him appreciate the broad spectrum of research performed under the IEN banner.
Though directing IEN will consume much of his time, Brand said, he will continue to direct a research group and expects to teach some courses as well.
"The research enabled by IEN has the potential to revolutionize medicine, help protect the environment, enhance homeland security, and provide fresh approaches in energy creation and storage," he said. "It can also improve the size, performance and effectiveness of devices and systems used in many other traditional consumer and industrial applications worldwide."
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]]>Biopharmaceutical drugs are frequently derived from discoveries made in university laboratories and licensed to biotechnology firms. Bottlenecks are well known during clinical trials, which have a high failure rate. But a new study pinpoints how much time is lost earlier in the pathway, when biotech companies give up on an invention and transfer the technology to other biotech firms for repurposing in a new disease category. Companies rarely share their basic research on an invention, which highlights what the researchers consider to be an underappreciated cost of commercialization as basic science research is then repeated, postponed, or never performed.
“The timeline for commercialization is much longer than most people think. There is so much turmoil and churn within the process,” said co-author Jerry Thursby, a professor and the Ernest Scheller, Jr. Chair in Innovation, Entrepreneurship, and Commercialization at the Scheller College of Business at the Georgia Institute of Technology.
The study was sponsored by the National Institutes of Health (NIH) and was published August 20 in the journal Science Translational Medicine.
The standard path to the marketplace for biotechnology is for universities to do most of the basic research and then license a discovery to a small biotechnology firm that advances the research. The small biotech firm will then sublicense the discovery to a large biotechnology firm that can afford to run clinical trials. The study found that basic research rarely proceeds in this straightforward path to commercialization, often zigzagging across biotech firms and research areas before a drug is finally developed.
“What these data reveal is that there’s a lot of bench to bench translational research. It’s not linear,” said Marie Thursby, a study co-author and the Hal and John Smith Chair in Entrepreneurship at the Scheller College of Business. Matthew Higgins, an associate professor of strategic management, was also a co-author of the study.
For the study, the researchers built a database of 835 patents in 342 university licenses with biotech firms. The researchers then traced the path of patents to document whether they were subsequently sublicensed to another firm for testing in a new disease category or whether the sublicense was to a large firm for clinical trials or marketing. Sublicensing often resets the development timeline in what the authors refer to as bench-to-bench translational research.
“A very large fraction of the time, an invention pops out as something else and the timeline for the discovery stage starts all over again,” said Jerry Thursby.
Of the 835 inventions studied, 27 percent appeared in a second license. The average time between invention and first license was five and a half years, and the average time between first- and second-license was three and a half years.
This time span for the upstream phase of the translation process is substantial, the study says, given that the average time from discovery to approval of new drugs (including biologics) by the U.S. Food and Drug Administration (FDA) is 13 years.
Of the first-licenses that list a stage of development, 92 percent were either at the discovery or lead molecule stages (the earliest two stages, respectively), with only 6 percent listed in clinical trials. Among the second-licenses, only 22 percent were in clinical trials or beyond.
“Nobody knew the magnitude of how much licensing changes and the stages at which they change,” said Marie Thursby. “The biotechnology industry is quite fragmented, and there are all sorts of informational problems.”
This analysis of early-stage biomedical translation suggests that stakeholders need to design policies and initiatives that enhance early translation by more efficiently driving more inventions into multiple disease pipelines.
One option might be the formation of an open-source translational research database that complements clinicaltrials.gov, where patents and licenses for fundamental biomedical research believed to be destined for eventual therapeutic use initially would be logged and shared.
“What might be a failure to a biotech firm could be a success to society as a whole,” Jerry Thursby said.
This research is supported and based on three separate subcontracts with the Office of Science Policy Analysis, Office of the Director, National Institutes of Health, under award number HHSN26320100002IC. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.
CITATION: Marie Thursby, et al., “Bench-to-Bench Bottlenecks in Translation.” (Science Translational Medicine, August 2014).
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]]>Today, Larkin’s children receive world-class medical care at her local hospital via a state-of-the-art telemedicine link to Marcus Autism Center. The recently improved telemedicine system was optimized by scientists at the Georgia Tech Research Institute (GTRI) and Cisco Systems, Inc. Marcus Autism Center’s telemedicine room is now a showcase for providers of telemedicine, where improved video capabilities and an ergonomic suite allow patients in rural Georgia to meet face-to-face with medical specialists in Atlanta.
“The accessibility to the doctors in Atlanta is the big thing,” Larkin said. “Not everyone has the means to make that kind of a drive. Telemedicine gives us access to the doctors that we normally wouldn’t have access to.”
A major goal of the telemedicine redesign is to create telepresence, clinical workflow, and diagnostic processes that can enable clinicians to identify rural children with autism spectrum disorders as early as 18 months. Today, these children are often diagnosed as late as seven years old.
GTRI’s telemedicine efforts are supported by a donation from Allen Ecker, a Georgia Tech alum and executive vice president of Scientific Atlanta.
“One of the biggest issues facing our country is both the cost of healthcare and the scarcity of healthcare providers as the demands of healthcare get larger,” Ecker said. “I think that telemedicine will address both of those problems. It reduces the cost of an appointment and it also reduces the time needed for the clinician.”
Cisco, as a provider of telemedicine equipment at Children’s Healthcare of Atlanta,also donated approximatelyhalf-a-million dollars’ worth of equipment and software toward telemedicine enhancements at both Marcus Autism Center and Children’s.
“Cisco worked hand-in-hand with us from the beginning,” said Courtney Crooks, a senior research scientist at GTRI, who is leading the project. “In a patient-provider relationship, the experience is really important. We wanted to ensure that the telepresence is at least as good as when you’re sitting in the office with a provider. Plus, we wanted to use technology to enhance the clinical workflow and capabilities of the provider, beyond what they may be able to accomplish through manual means.”
Felissa Goldstein, M.D., is the primary doctor using the improved telemedicine system at the Marcus Autism Center. Goldstein, a child and adolescent psychiatrist, is one of the most active providers of telemedicine in the state of Georgia. She uses the system for providing early screening and continuing care for children with autism spectrum disorders.
Until this past summer, Goldstein had been using a telemedicine system in her office that, among other human factors problems, had poor lighting, muffled sound, and displaced monitors which created heavily reduced eye contact.
The GTRI systems engineers applied their expertise to Goldstein’s clinical setting. They studied the best way to orient the telemedicine monitors so that the eye contact and visual connection between doctor and patient was optimized without either person having to crane their neck.
The old telemedicine system used two monitors side-by-side. The monitor on the left displayed medical records, while the monitor on the right provided a view of the patients via a webcam atop the monitor.
“I’d have to tell the family when I would start that ‘If I look away, it’s not because I’m not paying attention to you. It’s because I’m looking at your chart,’” Goldstein said.
The GTRI engineers saw that a redesign of the monitors was required; one which did not require the doctor to turn their head or shift their gaze in an obvious way.
Crooks’ team shadowed Dr. Goldstein during her appointments and developed a streamlined, ergonomic telemedicine system.Now the monitor that displays medical records is above the patient monitor. A powerful webcam sits in the space between the monitors. If Goldstein moves her gaze from the top monitor to the bottom monitor, all the patients see is a slight movement of her head. Goldstein said the improved eye-contact is the biggest advantage to the new system.
“GTRI worked with us really carefully to maximize eye contact, and I feel like it’s really adding to my ability to provide good patient care by telemedicine,” Goldstein said.
The new telemedicine system is now in a room of its own. The lighting in the larger space was designed to make Goldstein appear natural, and not dark and shadowy like in the old system. The desk and monitors are now ergonomic, and the room is soundproof.
Gone is the need for the old-fashioned webcam remote control, and in its place is an iPad which acts as the central control station for the telemedicine system. Goldstein now can tap the screen to control the camera. She can pan and zoom to follow children around the room as they play with toys, or tightly focus on the parents as they praise or discipline their children. The iPad is also enabled for capabilities such as touchpad tagging of behavioral events of interest that may occur during a session.
If Goldstein needs to note a significant event, she can flag it in the system. Later, she analyzes the data to look for trends, such as how a symptom develops over time.
Another improvement is the system’s ability to load unique settings for individual families. Goldstein can also share her screens remotely, as she does when giving lectures. This feature can also be used to share educational materials with families during session, as needed.
The new telemedicine system was transitioned over the summer of 2013. Crooks’ research team is in discussions with several other funders for ways to use the system for different clients’ needs, such as teletraining, parent education, and dependent care in the military. Those applications are still under development, but the system’s value to families with children is already changing their lives.
When Mandi Larkin arrives to her appointment at Tift Regional Medical Center with her children -- ages three, four and six -- a nurse guides them through registration and paperwork, then takes the kids’ vital signs and leads the family to the telemedicine room. When they arrive, Goldstein is already on the telemedicine video screen.
“It’s usually very prompt, and that’s something I really like,” Larkin said. “Once you get there you have your appointment time and there’s never more than a 5 minute wait.”
After her telemedicine session, Larkin is faxed a report detailing the visit. Before, she had to bring a pen and notepad to every appointment to have a record of what transpired.
Larkin said she would prefer to be with the doctor in person, but that isn’t realistic, so telemedicine is the next best thing. In some cases, telemedicine is even better than being with the doctor in person, Larkin said.
“I think the doctor gets a little bit more interaction from the kids through the screen because they more or less shut down around new people,” Larkin said. “With telemedicine, to the kids it’s just somebody on a TV screen talking to them. The doctor can see a little bit more and get a little bit more from them than if she was in the room in front of them.”
Research shows that children in rural areas, on average, aren’t diagnosed with autism spectrum disorders until age seven. Ideally, diagnosis should take place as early as 18 months so the children can benefit from proper care as early as possible. The new telemedicine system could help bring earlier diagnosis to rural children.
“We’re helping to screen a lot of children with developmental disabilities so that it’s no longer seven years until they are diagnosed,” Goldstein said. “The younger you can diagnose, the better off you are.”
Goldstein also travels to rural clinics throughout the state, where many of the families have never seen a specialist for children with developmental disabilities. Future work with the telemedicine system will convert all six of her outreach clinics to video conferencing clinics.
Overall, Children’s Healthcare of Atlanta partners with Georgia Partnership for Telehealth (GPT) to see patients at more than 30 telemedicine sites throughout the state of Georgia in a variety of specialties ranging from Cardiology to Sports Medicine. GTRI’s work with Marcus Autism Center will also be applied to other telemedicine suites at Children’s Healthcare of Atlanta.
“In collaboration with Cisco, we came up with a standard that other clinics can adopt,” Crooks said.
If enhancements to remote site systems are desired, this standard can be used to customize a suitable package that will be interoperable with the system at Marcus Autism Center. Sites may be eligible for funding for these upgrades through a variety of sources.
The work between GTRI, Cisco and Marcus is continuing with the ultimate goal of being able to perform diagnosis and therapy in the child patient's home, with the parents as the caregivers, directed by clinicians using the telemedicine system.
In the meantime, the new telemedicine system is already improving lives. Larkin has been using telemedicine for about three and a half years. To her family, it’s meant a major improvement in the quality of life.
“It’s all worth it because I get to see the doctor and I don’t have to drive three hours with my three autistic kids,” Larkin said.
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]]>Gathering and understanding this cyber-intelligence is the work of BlackForest, a new open source intelligence gathering system developed by information security specialists at the Georgia Tech Research Institute (GTRI). By using such information to create a threat picture, BlackForest complements other GTRI systems designed to help corporations, government agencies and nonprofit organizations battle increasingly-sophisticated threats to their networks.
“BlackForest is on the cutting edge of anticipating attacks that may be coming,” said Christopher Smoak, a research scientist in GTRI’s Emerging Threats and Countermeasures Division. “We gather and connect information collected from a variety of sources to draw conclusions on how people are interacting. This can drive development of a threat picture that may provide pre-attack information to organizations that may not even know they are being targeted.”
The system collects information from the public Internet, including hacker forums and other sites where malware authors and others gather. Connecting the information and relating it to past activities can let organizations know they are being targeted and help them understand the nature of the threat, allowing them to prepare for specific types of attacks. Once attacks have taken place, BlackForest can help organizations identify the source and mechanism so they can beef up their security.
Organizing distributed denial-of-service (DDoS) attacks is a good example of how the system can be helpful, Smoak noted. DDoS attacks typically involve thousands of people who use the same computer tool to flood corporate websites with so much traffic that customers can’t get through. The attacks hurt business, harm the organization’s reputation, bring down servers – and can serve as a diversion for other types of nefarious activity.
But they have to be coordinated using social media and other means to enlist supporters. BlackForest can tap into that information to provide a warning that may allow an organization to, for example, ramp up its ability to handle large volumes of traffic.
“We want to provide something that is predictive for organizations,” said Ryan Spanier, head of GTRI’s Threat Intelligence Branch. “They will know that if they see certain things happening, they may need to take action to protect their networks.”
Malware authors often post new code to advertise its availability, seek feedback from other writers and mentor others. Analyzing that code can provide advance warning of malware innovations that will need to be addressed in the future.
“If we see a tool pop up written by a person who has been an important figure in the malware community, that lets us know to begin working to mitigate the new malware that may appear down the road,” Smoak said.
Organizations also need to track what’s being made available in certain forums and websites. When a company’s intellectual property starts showing up online, that may be the first sign that a network has been compromised. Large numbers of credit card numbers, or logins and passwords, can show that a website or computer system of a retail organization has been breached.
“You have to monitor what’s out in the wild that your company or organization owns,” said Spanier. “If you have something of value, you will be attacked. Not all attacks are successful, but nearly all companies have some computers that have been compromised in one way or another. You want to find out about these as soon as possible.”
Monitoring comments on websites can also reveal what kinds of security reputations organizations may have. If the advice is to avoid a particular organization because previous attacks have failed, that can give an organization a sense that its security is good. Attackers often seek the easiest targets, Spanier noted.
Individual organizations could gather the kinds of information monitored by BlackForest, but few organizations have the resources to connect the information. GTRI customizes the system to gather information specific to each user and their industry segment.
“The average organization doesn’t have the means to crawl all of this data and put together the complex algorithms needed to identify the useful information,” Smoak explained. “Because we have the environment and the connectivity, we have what we need to obtain this information.”
By automating much of the work involved in gathering and monitoring information, BlackForest can allow human resources to be used for more challenging information security activities.
“Our goal is to have tools that will help focus the resources so that the most valuable resources are used for the more difficult issues,” said Smoak. “Right now, we tend to find all kinds of security fires the same. This will help us focus on the most important threats.”
BlackForest joins two other GTRI cyber-security systems already available. Apiary is a malware intelligence system that helps corporate and government security officials share information about the attacks they are fighting. Phalanx helps fight the spear phishing attacks that are carried out by tricking email recipients to open malware-infected attachments or follow malicious web links.
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]]>Department of Defense representatives were in attendance during a recent event where two of the low-power devices, which can change beam directions in a thousandth of a second, were demonstrated in an aircraft during flight tests held in Virginia during February 2014. One device, looking up, maintained a satellite data connection as the aircraft changed headings, banked and rolled, while the other antenna looked down to track electromagnetic emitters on the ground.
“We were able to sustain communication with the commercial satellite in flight as the aircraft changed headings dramatically,” explained Matthew Habib, a GTRI research engineer. “The antenna was changing beam directions to compensate for the aircraft headings. At the same time, we were maintaining communication with a device on the ground.”
In addition to rapidly altering its beam direction, the antenna’s frequency and polarization can also be changed by switching active components. The prototype used in this test operates from 500 to 3000 MHz with a plus or minus 60-degree hemispherical view. The latest prototypes have been able to provide gain to 6 GHz, opening more communication options to the end user. For the flight test, GTRI collaborated with SR Technologies, Inc. (SRT), a Florida company specializing in wireless engineering products. SRT provides mobile communications hardware including L-Band mobile satellite, 802.11 (WiFi), and cellular solutions.
For this effort, the A3 was matched with an SRT software defined radio focused on the L-Band mobile satellite frequency range. GTRI also collaborated with Aurora Flight Sciences to fly the antennas on their Centaur optionally piloted aircraft.
Beyond its ability to be easily reconfigured, the low power consumption and flat form make the Agile Aperture Antenna ideal for aircraft such as UAVs that have small power supplies and limited surface area for integrating antennas.
“If you have a large ship or aircraft with lots of power, you can afford to use a phased-array or other type of steerable antenna,” noted Habib. “But when you are using small vehicles, especially robotic aircraft and self-sustaining vehicles that don’t include an operator, our antenna is a great solution.”
Composed of printed circuit boards, the antenna components weigh just two or three pounds.
“It’s not just about the low power and weight,” said James Strates, also a GTRI research engineer. “The simplicity of the system, the low fabrication cost and the ability to retrofit the A3 to an existing system also make it attractive to operators.”
Beyond use on aircraft, ships and ground vehicles, the antenna concept could also find application in mobile devices, where the dynamic tunability could help cut through congestion on cellular networks, noted Ryan Westafer, a GTRI research engineer.
“A small electronically tunable antenna could provide a lot of new opportunities for mobile devices,” he said.
As configured for the flight tests, the upward-looking A3 antenna had a beam 30 degrees wide that could be shifted up to 60 degrees in either direction to maintain contact with the satellite. For the downward-looking antenna, the beam was automatically adjusted to “stare” at a point on the ground, reducing the interference from nearby emitters, Westafer explained.
Because it doesn’t require mechanically moving a metal dish, the A3 can change beam direction 120 degrees in a thousandth of a second, which gives it a significant response time advantage over gimbaled antennas.
The A3’s weight and complexity are also much less than for a phased-array antenna with similar capabilities. The A3 antenna uses just one static feed point, while a phased-array must feed and control each element separately. Because of its low power consumption, the A3 requires no cooling system.
The Agile Aperture Antenna has also been tested on a Wave Glider autonomous ocean vehicle. Together with previous testing on a moving ground vehicle, the new evaluations demonstrate the operational flexibility of the antenna, Habib said. So far, the A3 has operated successfully at temperatures as low as 10 degrees below zero Fahrenheit, and as high as 100 degrees Fahrenheit.
To track the satellite, the antenna uses an inertial measurement unit to provide information about the aircraft’s pitch, roll and yaw – as well as its longitude, latitude and altitude. That information is sent to a controller that turns elements off and on to the change the beam direction to maintain communication. Before takeoff, the researchers had programmed into the device the location of the commercial satellite with which it was communicating.
The challenge ahead is to take advantage of the antenna’s unique capabilities – and to affect the way operators place antennas onto ground, air and sea vehicles.
“This is changing the way that we think about integrating antennas onto systems to provide new solutions,” Habib said. “Users have not had these capabilities before, and we are excited to see how our partners will be able to take full advantage of this antenna.”
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]]>This is one of nature’s great laboratories. Yen and her team of scientists are conducting experiments here that are possible nowhere else. Outfitted in red parkas, they are not here to drill into frozen lakes or fly over thinning ice sheets. They spend what little daylight they have searching for tiny organisms in the frigid waters.
The scientists climb aboard the R/V Lawrence M Gould, a massive research vessel operated by the National Science Foundation (NSF). They cruise past giant icebergs and through rafts of loose ice to Palmer Deep, a location where the water is 2,000 feet (600 meters) deep. From the huge stern A-frame of the ship, they lower plankton nets into the zero-degree Celsius water and haul live animals aboard. In Antarctica, zero degrees Celsius is a pleasant day, but the recent bout of 80-knot wind gusts tells them the austral winter is on its way.
“The weather has been good,” Yen said. “We’ve gone out and have been collecting plankton all around.”
Yen, a professor of biology at the Georgia Institute of Technology in Atlanta, is on her second polar plunge. She’s an ecologist with an engineer’s eye. Her team of biologists and engineers haul each day’s catch back to the lab at Palmer Station, which provides no escape from the cold. There, the scientists study plankton swimming motion with video cameras in a room kept at zero degrees Celsius, to mimic the animals’ natural environment.
Plankton are the base of the food chain, but their environment is changing. Around the southern continent, the water temperature is stable at around zero degrees Celsius because of the Antarctic Circumpolar Current. Carbon dioxide, a potent greenhouse gas, easily dissolves in the cold water, acidifying the ocean. The acidifying oceans might be triggering a destructive chain of events underwater that could harm the food web around the world.
That’s why Yen and her team have come here, in search of a tiny organism that could be a canary in the coal mine of climate change.
The study discovered a path from simple to complex compounds amid Earth’s prebiotic soup. More than 4 billion years ago, amino acids could have been attached together, forming peptides. These peptides ultimately may have led to the proteins and enzymes necessary for life’s biochemistry, as we know it.
In the new study, scientists analyzed samples from an experiment Miller performed in 1958. To the reaction flask, Miller added a chemical that at the time wasn’t widely thought to have been available on early Earth. The reaction had successfully formed peptides, the new study found. The new study also successfully replicated the experiment and explained why the reaction works.
“It was clear that the results from this old experiment weren’t some sort of artifact. They were real,” said Jeffrey Bada, distinguished professor of marine chemistry at the Scripps Institution of Oceanography at the UC San Diego. Bada was a former student and colleague of Miller’s.
The study was supported by the Center for Chemical Evolution at the Georgia Institute of Technology, which is jointly supported by the National Science Foundation and the NASA Astrobiology Program. The study was published online June 25 in the journal Angewandte Chemie International Edition.The work was primarily a collaboration between UC San Diego and the Georgia Institute of Technology in Atlanta. Eric Parker, the study’s lead author, was an undergraduate student in Bada’s laboratory and is now a graduate student at Georgia Tech.
Jeffrey Bada was Stanley Miller’s second graduate student. The two were close and collaborated throughout Miller’s career. After Miller suffered a severe stroke in 1999, Bada inherited boxes of experimental samples from Miller’s lab. While sorting through the boxes, Bada saw “electric discharge sample” in Miller’s handwriting on the outside of one box.
“I opened it up and inside were all these other little boxes,” Bada said. “I started looking at them, and realized they were from all his original experiments; the ones he did in 1953 that he wrote the famous paper in Science on, plus a whole assortment of others related to that. It’s something that should rightfully end up in the Smithsonian.”
The boxes of unanalyzed samples had been preserved and carefully marked, down to the page number where the experiment was described in Miller’s laboratory notebooks. The researchers verified that the contents of the box of samples were from an electric discharge experiment conducted with cyanamide in 1958 when Miller was at the Department of Biochemistry at the College of Physicians and Surgeons, Columbia University.
An electric discharge experiment simulates early Earth conditions using relatively simple starting materials. The reaction is ignited by a spark, simulating lightning, which was likely very common on the early Earth.
The 1958 reaction samples were analyzed by Parker and his current mentor, Facundo M. Fernández, a professor in the School of Chemistry and Biochemistry at Georgia Tech. They conducted liquid chromatography- and mass spectrometry-based analyses and found that the reaction samples from 1958 contained peptides. Scientists from NASA’s Johnson Space Center and Goddard Space Flight Center were also involved in the analysis.
The research team then set out to replicate the experiment. Parker designed a way to do the experiment using modern equipment and confirmed that the reaction created peptides.
“What we found were some of the same products of polymerization that we found in the original samples,” Parker said. “This corroborated the data that we collected from analyzing the original samples.”
In the experiment from 1958, Stanley Miller had the idea to use the organic compound cyanamide in the reaction. Scientists had previously thought that the reaction with cyanamide would work only in acidic conditions, which likely wasn’t widely available on early Earth. The new study showed that reactive intermediates produced during the synthesis of amino acids enhanced peptide formation under the basic conditions associated with the spark discharge experiment.
“What we’ve done is shown that you don’t need acid conditions; you just need to have the intermediates involved in amino acid synthesis there, which is very reasonable,” Bada said.
Why Miller added cyanamide to the reaction will probably never be known. Bada can only speculate. In 1958, Miller was at Columbia University in New York City. Researchers at both Columbia and the close-by Rockefeller Institute were at the center of studies on how to analyze and make peptides and proteins in the lab, which had been demonstrated for the first time in 1953 (the same year that Miller published his famous origin of life paper). Perhaps while having coffee with colleagues someone suggested that cyanamide – a chemical used in the production of pharmaceuticals – might have been available on the early Earth and might help make peptides if added to Miller’s reaction.
“Everybody who would have been there and could verify this is gone, so we’re just left to scratch our heads and say ‘how’d he get this idea before anyone else,’” Bada said.
The latest study is part of an ongoing analysis of Stanley Miller’s old experiments. In 2008, the research team found samples from 1953 that showed a much more efficient synthesis than Stanley published in Science in 1953. In 2011, the researchers analyzed a 1958 experiment that used hydrogen sulfide as a gas in the electric discharge experiment. The reactions produced a more diverse array of amino acids that had been synthesized in Miller’s famous 1953 study. Eric Parker was the lead author on the 2011 study.
“It’s been an amazing opportunity to work with a piece of scientific history,” Parker said.
This research is supported by the Center for Chemical Evolution at the Georgia Institute of Technology, which is jointly supported by the National Science Foundation and the NASA Astrobiology Program under award number NSF CHE-1004570. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Eric T. Parker, et al., “A Plausible Simultaneous Synthesis of Amino Acids and Simple Peptides on the Primordial Earth.” (Angewandte Chemie, June 2014). http://dx.doi.org/10.1002/anie.201403683
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]]>“VentureLab is an outstanding business incubator that provides exceptional quality to its client companies and produces growth companies and high economic impact,” said Dhruv Bhatli, a co-founder of UBI Index. “VentureLab did really well on our global benchmark and beat numerous business incubators based at top universities. They are one of the best incubation places in the world and in North America, as evidenced by their performance on our global benchmark.”
In developing the rankings, UBI Index assessed 800 incubators worldwide from 66 countries, accepting 400 into the survey and benchmarking 300 of them. It evaluated more than 60 key performance indicators, including jobs created, incubator revenue, customers of clients, sales, revenue per client, successful graduates, survival and growth rate, partners and sponsors, survival rate of clients, funding available, venture capital and angel funding received, and the quality of active coaches and mentors available.
The UBI summary cited three high-level factors in the success of VentureLab, including an emphasis on company viability, a high quality network with investor contacts, and connections to Georgia Tech researchers for new technology development. The incubator’s companies have “a higher survival rate than the global average,” UBI said.
VentureLab helps Georgia Tech faculty, researchers and students identify opportunities for commercialization and create startup companies based on research results. Since VentureLab’s formation in 2001, it has helped launch more than 150 companies, which have raised more than $1.1 billion in outside capital. The program, based in Georgia Tech’s Enterprise Innovation Institute, is currently assisting approximately 100 startups in various stages of development.
Keith McGreggor, director of the VentureLab program, says the incubator’s success stems from its connections to both the academic and business worlds.
“We have embraced both houses,” he said. “We have embraced the academic side of the house with our educational programs, but that is informed by what we do day-to-day to create technology startups. When the people who are teaching entrepreneurship are also practicing it, that changes everything.”
He said VentureLab seeks out new research on entrepreneurship, including national best practices being taught by the National Science Foundation’s Innovation Corps (I-Corps), which helps researchers assess the commercial potential of research developments and understand the needs of entrepreneurship.
“We are able to bring this new thinking to bear on the classes that we are able to stand up on the academic side,” he added. “The entire way that entrepreneurship is taught today is different from what it was five years ago, and it will be different five years from now.”
VentureLab differs from many incubators in addressing a broad range of technologies that reflects the breadth of Georgia Tech’s research program. While computer science and Internet-based companies make up about 20 percent of the firms in the incubator, engineering-based startups in such areas as advanced materials, sensors and electronics make up a larger percentage of the incubator’s companies. VentureLab also has a significant number of biomedical device firms, reflecting the growing importance of life sciences research at Georgia Tech.
“We deal more with atoms than with bits,” McGreggor added.
Top universities in the world generally aren’t among the best at incubating new businesses, UBI said. Being an exception to that rule demonstrates the growing importance of entrepreneurship to Georgia Tech’s culture, McGreggor suggested.
“We are blessed with an evolving culture of entrepreneurship and the awareness of entrepreneurship as a career path,” he said. “The expectation for many students is that they will leave the university to do great work at a great corporation. Only recently has it become more expected and acceptable for graduates to create their own jobs by starting up a new company.”
In 2013, UBI Index ranked VentureLab second in first global survey of incubators. The 2013 survey included just 150 university-based incubators in 22 countries.
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]]>Around 4 billion years ago, the first molecules of life came together on the early Earth and formed precursors of modern proteins and RNA. Scientists studying the origin of life have been searching for clues about how these reactions happened. Some of those clues have been found in the ribosome.
The core of the ribosome is essentially the same in all living systems, while the outer regions expand and become complicated as species gain complexity. By digitally peeling back the layers of modern ribosomes in the new study, scientists were able to model the structures of primordial ribosomes.
“The history of the ribosome tells us about the origin of life,” said Loren Williams, a professor in the School of Chemistry and Biochemistry at the Georgia Institute of Technology. “We have worked out on a fine level of detail how the ribosome originated and evolved.”
The study was sponsored by the NASA Astrobiology Institute and the Center for Ribosomal Origins and Evolution at Georgia Tech. The results were published June 30 in the journal Proceedings of the National Academy of Sciences.
In biology, the genetic information stored in DNA is transcribed into mRNA, which is then shipped out of the cell nucleus. Ribosomes, in all species use mRNA as a blueprint for building all the proteins and enzymes essential to life. The ribosome’s job is called translation.
The common core of the ribosome is essentially the same in humans, yeast, bacteria and archaea – in all living systems. The Georgia Tech team has shown that as organisms evolve and become more complex, so do their ribosomes. Humans have the largest and most complex ribosomes. But the changes are on the surface – the heart of a human ribosome the same as in a bacterial ribosome.
“The translation system is the operating system of life,” Williams said. “At its core the ribosome is the same everywhere. The ribosome is universal biology.”
In the new study, Williams and Research Scientist Anton Petrov compared three-dimensional structures of ribosomes from a variety of species of varying biological complexity, including humans, yeast, bacteria and archaea. The researchers found distinct fingerprints in the ribosomes where new structures were added to the ribosomal surface without altering the pre-existing core.
Additions to the ribosome cause insertion fingerprints. Much like a botanist can carve back twigs and branches on a tree to learn about its growth and age, Petrov and Williams show how segments were continually added to the ribosome without changing the underlying structure. The research team extrapolated the process backwards in time to generate models of simple, primordial ribosomes.
“We learned some of the rules of the ribosome, that evolution can change the ribosome as long as it does not mess with its core,” Williams said. “Evolution can add things on, but it can’t change what was already there.”
For a video on the origins and evolution of the ribosome, visit: https://www.youtube.com/watch?v=ei6qGLBTsKM
This research is supported by the NASA Astrobiology Institute under award number NNA09DA78A. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.
CITATION: Anton S. Petrov, et al., “Evolution of the Ribosome at Atomic Resolution.” (June 2014, PNAS) http://www.pnas.org/cgi/doi/10.1073/pnas.1407205111
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]]>The researchers believe the process can be scaled up to inexpensively provide large membrane surface areas in compact modules. By replacing energy-intensive distillation or cryogenic techniques, these molecular sieving membranes could cut the cost of gaseous and liquid separations, reduce energy consumption – and lead to industrial processes that generate less carbon dioxide. The researchers have demonstrated that membranes produced with the new technique can separate hydrogen from hydrocarbon mixtures, and propylene from propane.
Development of the membrane fabrication methodology was described in the July 4, 2014, issue of the journal Science.
“This work opens up new ways of fabricating molecular sieving separation membranes using microscopic hollow fibers as a platform,” said Sankar Nair, a professor in the School of Chemical & Biomolecular Engineering at the Georgia Institute of Technology, and one of the paper’s co-authors. “Many of the separations that currently are done with energy-intensive techniques could one day be performed with membranes fabricated by a scaled-up version of our methodology.”
Energy-intensive separation processes are widely used in the industrial production of petro-based and bio-based fuels and chemicals, as well as a variety of other technological materials. The most common separation technique is distillation, which applies heat to chemical mixtures to drive off specific molecules according to their boiling points. Other techniques, such as crystallization, involve cooling to lower temperatures to separate the molecules from the mixtures.
In contrast, molecular sieving membranes use semipermeable materials to separate molecules from mixtures that are produced by chemical reactions or found in raw material feedstocks. The process may be driven by a pressure gradient, and relies on the membranes to preferentially pass certain molecules through their pore structures. Crystalline materials known as zeolites have been fabricated into membranes, but high membrane fabrication costs and a limited selection of materials have prevented their widespread use.
Metal-organic framework (MOF) materials offer an alternative with more benign fabrication methods and many thousands of material types available. But before MOF membranes could be used on a large scale, researchers had to find ways of producing them at low cost in large volumes.
The Georgia Tech technique for producing MOF membranes takes advantage of the large surface area that can be obtained by using large numbers of hollow fibers spun from inexpensive polymers. For instance, a one cubic meter hollow-fiber membrane module could contain as much as 10,000 square meters of membrane area.
The new fabrication process relies on a microfluidic technique for bringing the different reactants needed to form MOF membranes into contact inside the fibers. The inner diameter of the fibers may be 100 microns or less, limiting the amount of reactants present and changing the interplay of the physical and chemical forces that control membrane formation. By adjusting the flow and positioning of the reactants and their solvents, the researchers learned to control the location of the MOF membrane films, allowing their formation on the inside or outside of the fibers – and even within the structure of the fibers.
“We have combined a high-performance MOF material with a new fabrication technique to come up with a membrane that can be scaled up in an inexpensive way,” Nair explained. “A key realization behind this development is that if you want to scale up MOF membrane growth using hollow fiber modules, you have to first learn how to scale down their growth in the microscopic environments of individual hollow fibers.”
Once the researchers learned to fabricate a functional membrane using a single hollow fiber, they could simultaneously fabricate membranes in parallel on multiple hollow fibers that were pre-assembled into a module. The research reported in the journal produced membrane films made of the MOF ZIF-8 inside three fibers simultaneously. Ultimately, Nair believes large bundles of the polymer fibers could be pre-assembled into modules and then coated simultaneously with molecular sieving MOF membranes.
An important next step for the research is to develop a better microscopic understanding of the process.
“To optimize this technique and scale it up to thousands or even millions of fibers at a time, we need to dig deeper to understand how the chemical reactions and molecular transport processes leading to membrane formation can be controlled under the microscopic conditions that exist within the fibers,” Nair said.
Though the researchers have so far demonstrated the functionality of their membranes in gaseous separation processes of interest to the petrochemical industry, the membrane processing technique could have broader applications.
“The approach we have developed could open the door to a whole new class of molecular sieving, polycrystalline film membranes,” said Christopher Jones, a professor in the School of Chemical & Biomolecular Engineering and another of the paper’s co-authors. “Such membranes could revolutionize how oil and chemical companies carry out gas and liquid separations, for example, by replacing energy-intensive and expensive cryogenic distillation processes with more energy-friendly membrane separations.”
In addition to those already mentioned, the research team included first author Andrew J. Brown, a graduate student in the Georgia Tech School of Chemistry and Biochemistry. Other researchers included William J. Koros, a professor in the School of Chemical & Biomolecular Engineering; Nicholas A. Brunelli, now an assistant professor in the Department of Chemical and Biomolecular Engineering at The Ohio State University; Kiwon Eum, a graduate student in the Georgia Tech School of Chemical & Biomolecular Engineering; postdoctoral fellow Fereshteh Rashidi; and researcher J.R. Johnson, who is now at SABIC.
This work was supported by Phillips 66 Company.
CITATION: Andrew J. Brown, et al., “Interfacial Microfluidic Processing of Metal-Organic Framework Hollow Fiber Membranes, (Science 2014).
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]]>The underlying technology, known as synthetic aperture sonar (SAS), uses advanced computing and signal processing power to create fine-resolution images of the seafloor based on reflected sound waves. Thanks to the long-term vision and a series of focused efforts funded by the Office of Naval Research spanning back to the 1970s, SAS is becoming a truly robust technology. When it transitions to the fleet, the SAS will dramatically improve the Navy’s ability to carry out the mine countermeasures mission.
“The Navy wants to find sea mines,” said Daniel Cook, a GTRI senior research engineer. “There are systems that do this now, but compared to SAS, the existing technology is crude.”
The SAS research is funded by a grant from the Office of Naval Research, and is conducted in collaboration with the Applied Research Laboratory at the Pennsylvania State University. In the past year, the group has made strides in improving the ability to predict and understand sonar image quality and has published and presented their work at conferences.
Sonar systems emit sound waves and collect data on the echoes to gather information on underwater objects.
The Navy uses torpedo-shaped autonomous underwater vehicles (AUVs) to map swaths of the seafloor with sonar sensors. Perhaps the most well-known example is the Bluefin 21 used to search for Malaysian Airlines Flight 370. The AUVs zigzag back and forth in a “mowing the lawn pattern,” Cook said. These AUVs can map at a range of depths, from 100 to 6,000 meters.
SAS is a form of side scanning sonar, which sends pings to the port and starboard sides of the AUV and records the echoes. After canvassing the entire area, data accumulated by the sensor is processed into a mosaic that gives a complete picture of that area of the seafloor.
SAS has better resolution than real aperture sonar (RAS), which is currently the most widespread form of side scan sonar in use. RAS transmits pings, receives echoes and then paints a strip of pixels on a computer screen. RAS repeats this pattern until it has an image of the seafloor. This technology is readily available, and relatively cheap, but its resolution over long ranges is not good enough to suit the Navy’s mine hunting needs.
RAS sensors emit acoustic frequencies that are relatively high and are therefore quickly absorbed by the seawater. SAS uses lower frequency acoustics, which can travel farther underwater. Upgrading to SAS improves the range at which fine resolution pictures can be produced.
“RAS can give you a great looking picture but it can only see out 30 to 50 meters,” Cook said. “For the same resolution, SAS can see out to 300 meters.”
SAS does not create a line-by-line picture of the sea floor like RAS. Instead, SAS pings many times while recording the echoes on a hard drive for post-processing. Once the AUV surfaces, the hard drive is removed and the data is analyzed by computers in a complex signal processing effort. The processing converts the pings into a large, fine-resolution image of the seafloor. The commonly accepted measure for fine resolution is a pixel size of 1 inch by 1 inch, which is what SAS can achieve.
Tests of SAS in AUVs have produced fine-resolution images of sunken ships, aircraft, and pipelines. But when looking at an image of the seafloor from above, operators might have difficulty discerning the identity of simple objects. For example, certain mines have a circular cross section. When looking at a top-down image, an operator might not be able to tell the difference between a mine and a discarded tire. To discern if that circular-shaped object is a threat, operators consider the shadow that an object casts in the sonar image. A mine will cast a shadow that is easy to distinguish from those cast by clutter objects such as tires. The shadow contrast research will be used to help ensure that this distinction is as clear as possible.
"Predicting contrast has been a challenging problem for the sonar community," Cook said. "We have developed a compact model that allows us to compute contrast very quickly."
Improving contrast prediction can have a ripple effect in mine hunting capability. Naval officers will be better able to plan missions by predicting how good the shadows will be in a certain environment. This can lead to improved imagery, power conservation, and better performance for automatic target recognition software.
Mines are plentiful and easy to make. Some mines explode on contact. Others are more sophisticated, exploding or deploying torpedoes when their sensors detect certain acoustic, magnetic or pressure triggers. Some can destroy a ship in 200 feet of water.
“Mines are a terrible problem. They lie in wait on the seafloor, so you want to go find them with as few people in the process as possible, which is why we’re driven towards these autonomous vehicles with synthetic aperture sonar,” Cook said.
This research is supported by the Office of Naval Research under grant numbers N00014-12-1-0085 and N00014-12-1-0045. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Office of Naval Research.
CITATIONS: D. Cook, et al. “Synthetic aperture sonar contrast, in 1st International Conference and Exhibition on Underwater Acoustics,” June 2013, pp. 143–150.
Z.G. Lowe, et al. “Multipath ray tracing model for shallow water acoustics.” Proc. 11th Eur. Conf. Underwater Acoust., ECUA2012, Jul. 2012.
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]]>Marine algae fight other species of algae for nutrients and light, and, ultimately, survival. The algae that cause red tides, the algal blooms that color blue ocean waters red, carry an arsenal of molecules that disable some other algae. The incapacitated algae don’t necessarily die, but their growth grinds to a halt. This could explain part of why blooms can be maintained despite the presence of competitors.
In the new study, scientists used cutting-edge tools in an attempt to solve an old ecological mystery: Why do some algae boom and some algae bust? The research team used cultured strains of the algae that cause red tide, exposed competitor algae to its exuded chemicals, and then took a molecular inventory of the competitor algae’s growth and metabolism pathways. Red tide exposure significantly slowed the competitor algae’s growth and compromised its ability to maintain healthy cell membranes.
“Our study describes the physiological responses of competitors exposed to red tide compounds, and indicates why certain competitor species may be sensitive to these compounds while other species remain relatively resistant,” said Kelsey Poulson-Ellestad, a former graduate student at the Georgia Institute of Technology, now at Woods Hole Oceanographic Institution, and the study’s co-first author, along with Christina Jones, a Georgia Tech graduate student. “This can help us determine mechanisms that influence species composition in planktonic communities exposed to red tides, and suggests that these chemical cues could alter large-scale ecosystem phenomena, such as the funneling of material and energy through marine food webs.”
The study was sponsored by the National Science Foundation and was published June 2 in the Online Early Edition of the journal Proceedings of the National Academy of Sciences (PNAS). The work was a collaboration between Georgia Tech, the University of Washington, and the University of Birmingham in the United Kingdom.
The algae that form red tide in the Gulf of Mexico are dinoflagellates called Karenia brevis, or just Karenia by scientists. Karenia makes neurotoxins that are toxic to humans and fish. Karenia also makes small molecules that are toxic to other marine algae, which is what the new study analyzed.
“In this study we employed a global look at the metabolism of these competitors to take an unbiased approach to ask how are they being affected by these non-lethal, subtle chemicals that are released by Karenia,” said Julia Kubanek, Poulson-Ellestad’s graduate mentor and a professor in the School of Biology and the School of Chemistry and Biochemistry at Georgia Tech. “By studying both the proteins and metabolites, which interact to form metabolic pathways, we put together a picture of what’s happening inside the competitor algal cells when they’re extremely stressed.”
The research team used a combination of mass spectrometry and nuclear magnetic resonance spectroscopy to form a holistic picture of what’s happening inside the competitor algae. The study is the first time that metabolites and proteins were measured simultaneously to study ecological competition.
"A key aspect of this study was the use of high-resolution metabolomic tools based on mass spectrometry," said Facundo M. Fernández, a professor in the School of Chemistry and Biochemistry, whose lab ran the mass spectrometry analysis. "This allowed us to detect and identify metabolites affected by exposure to red tide microorganisms.”
Mass spectrometry was also used for analysis of proteins, an approach called proteomics, led by Brook Nunn at the University of Washington.
The research team discovered that red tide disrupts multiple physiological pathways in the competitor diatom Thalassiosira pseudonana. Red tide disrupted the energy metabolism and cellular protection mechanisms, inhibited their ability to regulate fluids and increased oxidative stress. T. pseudonana exposed to red tide toxins grew 85 percent slower than unexposed algae.
“This competitor that’s being affected by red tide is suffering a globally upset state,” Kubanek said. “It’s nothing like what it would be in a healthy, normal cell.”
The work shows that chemical cues in the plankton have the potential to alter large-scale ecosystem processes including primary production and nutrient cycling in the ocean.
The research team found that another competitor diatom, Asterionellopsis glacialis, which frequently co-occurs with Karenia red tides, was partially resistant to red tide, suggesting that co-occurring species may have evolved partial resistance to red tide via robust metabolic pathways.
Other work in Kubanek’s lab is examining red tide and its competition in the field to see how these interactions unfold in the wild.
“Karenia is a big mystery. It has these periodic blooms that happen most years now, but what’s shaping that cycle is unclear,” Kubanek said. “The role of competitive chemical cues in these interactions is also not well understood.”
This research is supported by the National Science Foundation under award number OCE-1060300. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.
CITATION: Kelsey L. Poulson-Ellestad, et al., “Metabolomics and proteomics reveal impacts of chemically mediated competition on marine plankton.” (June, PNAS) www.pnas.org/cgi/doi/10.1073/pnas.1402130111
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]]>AEgis Technologies, specialists in modeling and simulation, contracted GTRI’s Applied Systems Laboratory to collaborate with MDA on testing high-altitude air defense missiles. ASL is in its second phase of a multi-year project utilizing “hardware-in-the-loop” testing to enable more accurate modeling and simulation for its customer.
“Testing a missile can be very expensive,” said GTRI Senior Research Engineer and principal investigator Glenn Parker. “Additionally, because of the large number of control variables in a real exercise, it isn’t technically feasible to get complete testing coverage. High-fidelity simulation addresses many of these concerns, but even with modern processors it can take days to compute the trajectory and heat signature of a complex ballistic target.”
Hardware-in-the-loop simulations use portions of the real missile hardware, such as the seeker, with any missing pieces made up by simulated components.
“We use the missile’s actual guidance system and manipulate simulated inputs to make the hardware think it is flying,” Parker said. “By using real hardware in tests, confidence in the results is much higher than in fully simulated models. For non-reusable portions of the missile like the motor and warhead, the use of simulation models makes it possible to run thousands of test cycles without leaving the laboratory, and for less than the cost of one live test.”
With current testing models, thermal signature databases must be computed offline prior to the test, and can take up to three days for a mere fifteen minutes of simulation time. Any alteration to the parameters—altitude, weather, terrain, or even the position of the sun—requires a total re-coding of the database. Testing a missile launch from Hawaii, for example, to intercept a target at a certain distance, altitude and speed takes a long time to calculate all of the missile hardware inputs that are used in the test.
What GTRI is working on, according to Parker, will enable the simulated components to be “looped in” for real-time calculation, eliminating the need for database computation ahead of time. Using off-the-shelf NVIDIA graphics cards, the group will work to provide the seeker with simulated thermally emissive ballistic targets heated by atmospheric effects in real time. The team will be using CUDA, NVIDIA’s parallel computing architecture.
“Our goal is to calculate and provide inputs at up to 200 Hz, which means simulated measurements are sent to the seeker unit 200 times each second,” Parker said. “This will allow us to run dozens of tests in the amount of time we used to spend calculating data for a single run. Test parameters can be changed on the fly—MDA will be able to run many more ‘what if’ scenarios before fielding a defense system.”
AEgis Technologies in Huntsville is the prime contractor of the project. They will operate the Army-owned, hardware-in-the-loop test bed and generate scenarios for use in simulations.
GTRI provides the expertise in real-time computing. Prior to this, AEgis had worked indirectly with GTRI’s Electro-Optical Systems Laboratory (EOSL) on the same program, which supported ultraviolet sensor testing.
“We selected GTRI based on what I knew of EOSL’s capabilities, and their expertise in GPU technology,” said AEgis Program Manager Dennis Bunfield. “GTRI’s CUDA expertise is a great value, and their expertise in verification and validation is invaluable.”
The system will be scalable, and the plan is to take what they learn from this project and use it elsewhere in the defense industry. The thermal solver aspect of the project, for example, will be useful for any simulation requiring a real-time solution for thermal image simulation.
“I think with some enhancements to the code framework, the capabilities can be extended to generate signatures in other regions, such as UV, the visible spectrum and for LADAR,” Bunfield said. “Aside from military applications, it could be possible to use the thermal solver to commercial and manufacturing applications, such as thermal analysis simulation.”
“We’re working with AEgis Technologies to best model and simulate firing and the performance of these missiles by providing scenario inputs at the true hardware rate,” Parker said. “Our main goal—writing a massively parallel NVIDIA CUDA thermal differential equation solver—will enable faster and more effective testing of high-cost components at hardware-in-the-loop testing centers.”
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]]>Despite the great potential, however, quantum computing faces many significant challenges, including controlling the qubits and isolating them from a noisy environment. Scientists and engineers at the Georgia Tech Research Institute (GTRI) are helping address those challenges by designing, fabricating and testing new components and devices aimed at supporting international quantum computing efforts.
GTRI’s Quantum Information Systems (QIS) Branch uses individual trapped atomic ions as qubits in its research. In collaboration with university and industry partners, QIS scientists recently demonstrated two new ion traps, including one that uses a system of integrated mirrors to read data from multiple ions. The researchers also advanced concepts for integrating the electronic systems needed to control the ion traps inside the vacuum containers within which the traps operate. The research was sponsored by the Intelligence Advanced Research Projects Activity (IARPA) through the Army Research Office (ARO) and the Space and Naval Warfare Systems Command (SPAWAR).
“We have a wide interest in developing the technologies needed by the field and using those technologies to perform the science needed to make advancements in quantum computing,” said Alexa Harter, chief scientist of GTRI’s Advanced Concepts Laboratory and head of the Quantum Information Systems Branch. “These are all projects that move us farther along the path of integration and technology development.”
On its website, the Quantum Information Systems Branch displays diagrams for a dozen micro-fabricated ion traps, each with special properties, many of them intended to work with other devices also designed by the group. The planar ion traps are based on silicon VLSI technology and are both fabricated and tested at GTRI. The ion traps and other quantum components developed in GTRI are shared with collaborators and others in the community who are focused on the same goal.
“We now have a very impressive tool kit of technologies, techniques and systems that can be integrated for use by us and our collaborators,” said Curtis Volin, a GTRI principal research scientist in the Quantum Information Systems Branch. “Our ultimate objective is to understand what would be necessary to build a quantum computer.”
Among the recent accomplishments:
• In collaboration with Griffith University in Australia, researchers developed ion traps with integrated diffractive mirrors. High fidelity ion qubit measurements are performed by collecting laser-induced ion fluorescence, but the speed of these measurements is limited by the ability to collect the emitted light. Integrating micro-mirrors into the traps provides a more efficient way to measure the internal states of the ions by allowing more of the photons they produce to be collected. In conventional ion traps, there is only one large lens to collect data from a single ion.
“To advance quantum computing, not only do you need to trap the ions, but you also need to be able to control them and read information from them,” Volin explained. “With these integrated mirrors, we can look at as many qubits as we want, eliminating one of the obstacles to quantum research.”
The micro-mirror traps have been designed, fabricated and tested.
• The researchers have designed a new micro-fabricated ion trap with integrated microwave elements for manipulating the coherent states of ion chains. Directly manipulating qubits with microwave fields reduces system complexity and sensitivity to emission decoherence.
• Working with colleagues at Honeywell, the researchers developed a technique for integrating the electronics that control the ion traps into the devices so they can operate within vacuum chambers. That will allow an increase in the number of leads that control the ion trap, and facilitate efforts to scale up the systems to accommodate larger numbers of ions.
“We are taking these components to a new level of integration,” Harter said. “If you want to make quantum sensors that can be used in the field or develop a quantum computer of larger size, you will need to integrate the optics and electronics.”
The integrated electronic interface was fabricated using unique facilities at Honeywell. It replaced banks of electronic equipment, and could potentially allow thousands of leads to be connected.
Harter says GTRI’s niche is to work with both academic and industrial researchers to bring engineering approaches to the quantum physics discoveries coming out of labs around the world.
“The basic physics research being done on campuses around the country requires a lot of engineering to make advances in quantum computing,” she said. “Much of what we do is really engineering these basic systems that we want to make available to our collaborators.”
GTRI’s Quantum Information Systems Branch is composed of 15 scientists, engineers and students who investigate the physics of trapped ions, develop micro-fabricated ion traps and model quantum architectures, Harter noted. The group also has collaborations with academic scientists at Georgia Tech.
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]]>“It’s estimated that each year U.S. farmers lose 12 percent of their crops to pests and another 12 percent to diseases,” said Gary McMurray, division chief of GTRI’s Food Processing Technology Division.
To identify potential threats to crop health, farmers typically look for physical symptoms of disease, such as discolored or wilting leaves. However, in many cases, by the time these symptoms are visible, the plant is already dead or dying. And the culprit pathogen may have already spread to nearby plants, threatening the health of the entire crop.
“The key is to give farmers the ability to get early diagnostic results, which allows them to take action before it’s too late,” said McMurray.
GTRI’s micro gas chromatograph is a GC-on-chip device. Its separation column, where the gas interacts with the polymer coated on the interior walls, is about the size of a quarter, and the thermal conductive detector is about half the size of a penny. When the two are combined, the device itself is about the size of a 9-volt battery.
McMurray said the goal is to be able to fit dozens of micro GCs on a ground robot that a farmer could then use in crop fields to take samples from plant to plant and get results in minutes.
“The idea is to have the robot be a mobile chemical laboratory that provides real-time data to the farmer. The robot provides a simple way to collect the data in an unstructured environment like a farm,” said McMurray.
Because all plants and pathogens emit volatile organic compounds (VOCs), these emissions can be used as chemical markers for rapid detection. Building the micro GC was the easy part, said Jie Xu, GTRI senior research scientist. The challenge now, she explained, is correlating the VOCs emitted from plants to their health status.
“It’s relatively easy to detect VOCs, but we still have a long way to go to interpret changes in plant VOC mixtures,” said Xu.
The difficulty lies in understanding how plants react to local environmental conditions. For example, changes in temperature, humidity, and soil moisture and nutrient levels, all have an effect on VOC emissions.
To determine if the emissions are due to a pathogen, a chemical signature has to be established by studying VOCs released under these different environmental conditions.
Researchers plan to conduct field tests using a benchtop model of the micro GC in summer 2014. Working with colleagues at the USDA’s Agricultural Research Service, they will test peach trees for Peachtree Root Rot disease at the Southeastern Fruit and Tree Nut Research Laboratory in Byron, Ga. The goal is to collect air and soil samples that can be analyzed to identify the disease’s chemical signature.
McMurray said a portion of the collected samples will be retained for additional laboratory tests with a traditional GC-MS to confirm the effectiveness of the micro GC. The team will then pursue efforts to integrate it into an autonomous robotic platform for crop field sampling and VOC data analysis.
“Real-time data from sensing technologies like the micro GC, when used in conjunction with other data collected on the farm, could revolutionize the ability of farmers to identify sick plants before any physical symptoms appear,” added McMurray.
Earlier detection also means earlier intervention, which could ultimately translate into a boon for America’s farmers. “If we could cut in half the 12 percent of crop losses due to diseases, farmers could potentially realize billions of dollars more in revenue each year,” said McMurray.
In addition to agricultural applications, the micro GC could potentially be used for homeland security monitoring to detect chemical threats, such as gases in subways and dangerous explosives in vehicles.
The micro GC project is being conducted in collaboration with researchers at GTRI, Georgia Tech’s George W. Woodruff School of Mechanical Engineering and the Parker H. Petit Institute for Bioengineering and Bioscience, the Department of Plant Pathology in the University of Georgia’s College of Agricultural and Environmental Sciences, and the USDA’s Agricultural Research Service.
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]]>A new technology under development at the Georgia Institute of Technology could one day provide more efficient delivery of the bone regenerating growth factors with greater accuracy and at a lower cost.
In a recent study, researchers bound the most clinically-used growth factor with microparticles of the drug heparin at concentrations up to 1,000-fold higher than previously reported. The growth factor, called bone morphogenetic protein-2 (BMP-2), also remained bioactive after long periods of time spent bound to the microparticles.
“The net result is more efficient and spatially controlled delivery of this very potent and very valuable protein,” said Todd McDevitt, an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. McDevitt is also the director of Georgia Tech’s Stem Cell Engineering Center.
The study was sponsored by the National Institutes of Health (NIH) and the National Science Foundation (NSF). The research results were published May 28 in the online edition of the journal Biomaterials. The work was a joint effort of several labs that are part of Georgia Tech’s Petit Institute for Bioengineering and Bioscience. Marian Hettiaratchi, a graduate student in McDevitt's lab, was the paper's lead author.
“This paper is a great example of the type of collaborative interdisciplinary research success that is enabled by three independent research groups working together towards solving a significant problem,” said Robert Guldberg, executive director of the Petit Institute for Bioengineering and Bioscience. “We are very excited about the potential for the heparin microparticle technology to improve the safety and efficacy of recombinant protein delivery for tissue regeneration clinical applications.”
The research team developed a method of fabricating pure heparin microparticles from a modified heparin methacrylamide species that can be thermally cross-linked to growth factors. The technology avoids the bulky materials currently used to deliver growth factors.
Heparin is a widely used anticoagulant with chemical properties that make it ideal for binding to growth factors. The researchers found that heparin microparticles bound BMP-2 with high affinity, exceeding the maximum reported growth factor binding capacity of other heparin-containing biomaterials by greater than 1,000-fold.
Current BMP-2 delivery techniques use a collagen sponge, which releases large amounts of the drug in an initial burst. To compensate for the high initial dose, excess growth factor is loaded into the sponge, leading to non-specific and inefficient delivery of the drug. The new study reported that BMP-2 stayed tightly bound to the heparin microparticles, so it is released slowly over time. After 28 days, just 25 percent of the growth factor had been released from the microparticles.
"The microparticles developed in this work have an extremely high loading capacity for BMP-2, which represents an advantage over current technologies,” said Johnna Temenoff, an associate professor in the Coulter Department. “These microparticles can localize high concentrations of protein therapeutics in an area of tissue damage without introducing large amounts of biomaterial that may take up space and prevent new tissue formation."
BMP-2 also maintained its bioactivity as it was released from microparticles during an in vitro assay. BMP-2-loaded microparticles in physical contact with cell culture also stimulated an increase in the number of cells.
Future work in the project will be to ensure that the growth factor maintains its bioactivity in vivo when bound to the heparin microparticles.
“If we can get a more robust response by actually using less growth factor, then I think we’re on to something that can be a more efficient delivery system,” McDevitt said.
This research is supported by a Transformative Research Award from the National Institutes of Health (NIH), award number (TR01 AR062006), and the National Science Foundation (NSF), under award number DMR 1207045. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Marian H. Hettiaratchi, et al., “Heparin Microparticle Effects on Presentation and Bioactivity of Bone Morphogenetic Protein-2.” (Biomaterials, May 2014). http://dx.doi.org/10.1016/j.biomaterials.2014.05.011
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]]>A new technology under development at the Georgia Institute of Technology could one day provide more efficient delivery of the bone regenerating growth factors with greater accuracy and at a lower cost.
]]>404-385-1933
]]>Researchers found the risk signature by comparing gene expression profiles in 31 study subjects who died of cardiovascular causes against the profiles of living members of the study group. Twenty-five of the 31 deaths occurred in the group with the high-risk profile, though coronary deaths were also recorded among the lower risk members of the study group. All of the patients studied had coronary artery disease (CAD), and about one in five had suffered a heart attack prior to the study.
Researchers from the Georgia Institute of Technology, Emory University and Princeton University participated in the study, which obtained gene expression profiles from blood samples taken from patients undergoing cardiac catheterization at Emory University clinics in Atlanta. The results were published in the open-access journal Genome Medicine on May 29, 2014.
“We envision that with our gene expression-based marker, plus some biochemical markers, genotype information and family history, we could produce a tiered evaluation of people’s risks of adverse coronary events,” said Gregory Gibson, director of the Center for Integrative Genomics at Georgia Tech and one of the study’s senior authors. “This could lead to a personalized medicine approach for people recovering from heart attack or coronary artery bypass grafting.”
Coronary artery disease is the leading cause of death for both men and women in the United States. Manifested in the narrowing of blood vessels through the buildup of plaque, CAD sets the stage for heart attacks and long-term heart failure.
As many as half of Americans over the age of 50 suffer from CAD to some extent, so the researchers wondered if they could single out those with the highest risk of death. From a cohort of more than 3,000 persons known as the Emory Cardiovascular Biobank (EmCD), they selected two groups of patients for extensive gene expression analysis based on blood samples.
After following the patients for as long as five years, the researchers examined gene expression patterns in a total of 31 persons from the study group who had suffered coronary deaths. Comparing these patterns against those of other study subjects revealed a pattern in which genes affecting inflammation were up-regulated, while genes affecting T-lymphocytes were down-regulated.
The patients studied ranged in age from 51 to 73, were mostly Caucasian, and 65 percent male. Seventy percent of the subjects had significant CAD, and 18 percent were experiencing an acute myocardial infarction when blood samples were taken. Gene expression was analyzed using microarrays and two different normalization procedures to control for technical and biological covariates. Whole genome genotyping was used to support comparative genome-wide association studies of gene expression. Two phases of the study were conducted independently with the two different groups, and produced similar results.
“What’s new in this research is the recognition that this risk pathway exists and that it relates to particular aspects of immune system functions that include T-cell signaling,” said Gibson, who is also a professor in Georgia Tech’s School of Biology. “We went beyond the signature of coronary artery disease to really provide a signature for adverse outcomes in that high-risk population.”
The pattern, said Gibson, doesn’t indicate the causes of the disease. The researchers would now like to expand the study to include a larger group of patients and learn more about what causes the disease. They’d also like to know whether the risks can be reversed through diet, exercise or drug therapy.
Cardiologist Arshed Quyyumi, the paper’s other senior author, directs Emory University’s Clinical Cardiovascular Research Center and created the Biobank five years ago to facilitate cardiovascular research. He says that identifying patients at highest risk could help encourage their compliance with treatment programs, and prioritize introduction of newer therapeutics, such as cholesterol lowering medications like PCSK9 inhibitors.
“A number of patients with CAD are currently not maximally treated,” said Quyyumi, who is a professor in Emory’s School of Medicine. “In those that appear to have been prescribed adequate medication, a significant proportion of subjects are non-compliant with their medications. Thus, knowledge of a high risk genetic profile in a patient can prompt both the patient and physician to maximize currently available medications and improve patient compliance.”
Approximately 15,000 genes are expressed in human blood, but analyzing them is not as daunting as it sounds. Most of the gene expression is correlated, so there may be only a few dozen independent measurements that can be related to disease states, Gibson said. In the study, researchers identified nine “axes” that represented specific biological pathways to disease. Two of them were relevant to the high-risk profile.
Gibson believes identifying the high-risk signatures in CAD patients may lead to opportunities for improving their health.
“Our dream would be a hand-held device that would allow patients to take a droplet of blood, much like diabetics do today, and obtain an evaluation of these transcripts that they could track at home,” he said. “If we can use this information to help people adopt healthier behaviors, it will be very positive.”
In addition to those already mentioned, the co-authors include Jinhee Kim, from the Georgia Tech School of Biology; Nima Ghasemzadeh and Danny Eapen from the Emory University School of Medicine, and John Storey and Neo Christopher Chung from the Lewis-Sigler Institute at Princeton University.
CITATION: Jinhee Kim, Nima Ghasemzadeh, Danny J. Eapen, Neo Christopher Chung, John D. Storey, Arshed A. Quyyumi and Greg Gibson, “Gene expression profiles associated with acute myocardial infarction and risk of cardiovascular death.” (Genome Medicine 2014). http://genomemedicine.com/content/6/5/40.
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]]>To aid this effort, researchers from the Georgia Tech Research Institute (GTRI) are helping to improve the capabilities of the nation’s Multi-Disciplinary Intelligence (Multi-INT) system, which monitors incoming data.
A key to improving the U.S. Multi-INT system involves bringing "actionable intelligence" – information that could require immediate response – to the attention of human analysts as quickly as possible, explained Chris Kennedy, a research program analyst who leads the MINT effort in GTRI. But finding actionable intelligence is a challenge; it must be identified from myriad raw data gathered by intelligence sources, which include optical and radar sensors, communications sensors, measurements and signatures intelligence (MASINT) and others.
"The number of analysts is limited, and they can only perform a certain number of actions," said Kennedy. "So out of a huge set of information – which could involve millions of data points – you need to find the most valuable pieces to prioritize for investigation and possible action."
Accelerating the System
GTRI's work addresses two related Multi-INT challenges:
Metadata are small amounts of information that contain the key elements of a data point, which is an individual piece of data. For example, in the case of a car moving down a road, its metadata might consist of the make/model/color, location, speed and number of passengers. Those attributes are highly informative, yet much easier to transmit and process than, say, a video of the car, which would involve large amounts of data.
The GTRI approach creates metadata fields, or utilizes existing ones, thereby characterizing each data point with minimal overhead. Then only the metadata is transmitted to the main system for immediate processing; the rest of the raw data is retained in an archive in case it's needed later.
The metadata technique results in much smaller amounts of information being relayed from ISR sources to computers. That reduces processing loads, helping computers and networks keep up with incoming data. The raw data is also stored and can be examined if necessary.
"Obviously under this data-reduction approach there are information losses that could affect how our program makes decisions, which is why our system is only a tool for – and not a replacement for – the human analyst," Kennedy said.
Informing the Analyst
The second challenge – supporting human analysts – is addressed by methods that improve the system's ability to identify, compare and prioritize different types of information.
First, the gathered metadata is converted into a single uniform format. By creating one format for all incoming metadata, data points from many different sources can be more readily identified and manipulated. This uniform format is independent of the data source, so different types of ISR data can be processed together.
Then, utilizing the identity-bearing metadata tags, GTRI researchers use complex machine-learning algorithms to find and compare related pieces of information. Powerful concurrent-computing techniques allow problems to be divided up and computed on multiple processors. That helps the system perform the complex task of determining which data points have been previously associated with other data points.
Metadata approaches have been used in the past, Kennedy explained, but only for a single intelligence technology – such as a text-recognition program that identifies keywords in voice-to-text data. The GTRI approach differs because it integrates metadata from a variety of intelligence disciplines into a single technology that prioritizes corroborative relationships from multiple sources.
Under GTRI's integrated approach, one set of potentially significant signals could be quickly compared to others in the same vicinity to form an in-depth picture. For example, in a disaster relief scenario, one aircraft-mounted ISR sensor might detect information indicating abandoned vehicles. But if another sensor detected a functioning communications device in one of the vehicles, that would indicate a higher likelihood of finding a survivor, prompting a rescue reconnaissance.
The relationship found between the communications device’s signal information and the vehicle’s imagery information would be prioritized against other found relationships and displayed to the analyst on mapping software, such as GTRI’s FalconView program.
Ongoing Improvement
Recently, the MINT team began working with a GTRI group that’s involved in the ongoing development of Stinger, a Georgia Tech-produced graph-analysis software. Stinger’s capabilities could aid MINT in recording and analyzing information about long-term patterns of observed relationships – that, for instance, a type of vehicle and a specific communications device are frequently observed together by independent sensors.
This information would then be sent to an analyst through a web-based portal, giving the analyst access to alerts regarding specific kinds of relationships identified by MINT.
The MINT team is presently focused on improving the program’s capacity to process many data points quickly. They're using three primary sets of testing data involving thousands or millions of data points over lengthy time spans. The researchers' goal is to achieve real-time or near-real-time processing capability, so analysts can be alerted to abnormal information almost instantly.
"We want to get to the point where, as the latest data is coming in, it's being correlated against the data we already have," Kennedy said. "We need to able to say to the analyst, 'OK you’ve got a million data points, but look at these 10 first.' "
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]]>When the predator population becomes too large, however, the prey population often plummets, leaving too little food for the predators, whose population also then crashes. This canonical view of predator-prey relationships was first identified by mathematical biologists Alfred Lotka and Vito Volterra in the 1920s and 1930s.
But all bets are off if both the predator and prey species are evolving in even small ways, according to a new study published this week in the journal Proceedings of the National Academy of Sciences. When both species are evolving, the traditional cycle may reverse, allowing predator populations to peak before those of the prey. In fact, it may appear as if the prey are eating the predators.
Researchers at the Georgia Institute of Technology have proposed a theory to explain these co-evolutionary changes. And then, using data collected by other scientists on three predator-prey pairs – mink-muskrat, gyrfalcon-rock ptarmigan and phage-Vibrio cholerae – they show how their theory could explain unexpected population cycles.
The new theory and analysis of these co-evolution cycles could help epidemiologists predict cycles of disease and the virulence of infectious agents, and lead to a better understanding of how population cycles may affect ecosystems. The research was supported by the National Science Foundation and the Burroughs Wellcome Fund.
“Our work shows that co-evolution can yield new and unique behavior at the population scale,” explained Joshua Weitz, an associate professor in the School of Biology at Georgia Tech. “When you include evolution, the classic prey-predator dynamics have a much greater range of possible outcomes. We are not replacing the original theory, but proposing a more general model that opens the door to these new phenomena.”
Evolution is often perceived as an historical event, noted Weitz, who also has a courtesy appointment in the Georgia Tech School of Physics. But organisms are evolving continuously, with certain phenotypes becoming dominant as environmental and other conditions favor them. In organisms such as birds or small mammals, those changes can be manifested in as few as ten generations. In microbial species with brief lifespans, evolutionary changes can happen within days or weeks.
Evolutionary changes can dramatically affect relationships between species, potentially making them more vulnerable or less vulnerable. For instance, if a mutation that confers viral resistance in a species of bacteria becomes dominant, that may change the predator-prey relationship by rendering the bacteria population safe from harm. More generally, co-evolutionary cycles can arise when predator offense is costly and prey defense is effective against low offense predators.
“With predator and prey co-evolution, you can see oscillations in which there are lots of prey around even when there are many predators, or lots of predators around even when there are very few prey,” noted Michael Cortez, a postdoctoral fellow in the Weitz lab and first author of the paper.
“When prey is abundant and there are few predators, it may be because there are many defended prey – prey that the predators can’t eat,” he added. “When there are lots of predators around and few prey, it’s because the prey are very good food sources and the predators are doing quite well.”
In their paper, Weitz and Cortez simulated models in which the evolutionary process was sped up to show how their theory of co-evolution would affect predator-prey population cycles. Speeding up the process allowed them to break the cycle up into smaller segments that could be analyzed in more detail. They then used the earlier observations of the changing abundances of the three pairs of predators and prey -- leveraging data sets collected by other scientists – to show how the models would apply.
“Although the structure of the cycles in these three systems had been noted as unusual by the authors who observed them, there had been, as yet, no unified theoretical framework from which to make sense of such as radical departure from the classic signature of predator-prey interactions,” Weitz said.
Scientists have long studied how the interaction between species affects overall populations in ecosystems. Weitz and Cortez believe their new model will give scientists a broader and more complete picture of the complex process.
“This study identifies how adaptation between two species and interactions between their numbers can result in something different from what you would get if you just had the interaction between the numbers,” said Cortez. “This is something that will show up across many ecological systems. We can now explain broad trends that occur in vastly different systems using a theoretical approach, and the fact that we can identify the mechanism responsible for it is unique to our study.”
This research was supported by the National Science Foundation under Award DMS-1204401, and by the Burroughs Wellcome Fund. Any conclusions or opinions expressed are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Michael H. Cortez and Joshua S. Weitz, “Coevolution Can Reverse Predator-Prey Cycles,” (Proceedings of the National Academy of Sciences, 2014). www.pnas.org/cgi/doi/10.1073/pnas.1317693111
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]]>“What we found is that there are some cancer cells that respond to softness as opposed to stiffness,” said Michelle Dawson, an assistant professor in the School of Chemical and Biomolecular Engineering at the Georgia Institute of Technology. “Ovarian cancer cells that are highly metastatic respond to soft environments by becoming more aggressive.”
Ovarian cancer cells spread, or metastasize, by a different method than other cancer cells. Breast cancer cells, for example, break off from a solid tumor and flow through the blood until they arrest in small blood vessels. The cancer cells then penetrate the vessel surface to form a tumor. Because ovarian tumors are in the abdomen, these cancer cells are shed into the surrounding fluid and not distributed through the blood. They must be able to adhere directly to the fatty tissue that lines the gut, called the omentum, to begin forming a tumor. The new study discovered details about how ovarian cancer cells seem to prefer the mechanical properties of this soft tissue.
The study was published in a recent advance online edition of the Journal of Cell Science and was sponsored by the National Science Foundation and the Georgia Tech and Emory Center for Regenerative Medicine.
The research team, led by Daniel McGrail, a graduate student in the Dawson lab, found that ovarian cancer cells in vitro were more adherent to a layer of soft fat cells than a layer of stiffer bone cells, and that this behavior was also repeated using gels of similar rigidities.
“All the behaviors that we associate with breast cancer cells on these more rigid environments are flipped for ovarian cancer cells,” Dawson said.
After adhering to these soft surfaces, metastatic ovarian cancer cells became more aggressive. Their proliferation increased and they were less responsive to chemotherapeutics. The ovarian cancer cells were also more motile on soft surfaces, moving nearly twice as fast as on rigid surfaces.
The team also found that less aggressive cells that do not metastasize do not exhibit any of these changes.
The researchers used techniques that haven’t been traditionally used in the study of ovarian cancer. They measured the force exerted by the cells by tracking the displacement of beads in the environment around the cells. The researchers found that the metastatic cells increased their traction forces – used to generate motion – by three-fold on soft surfaces, but no such change was present in the less aggressive cells.
“We think the behavior that metastatic ovarian cancer cells exert on these soft surfaces is representative of the mechanical tropism that they have for these softer tissues in the gut,” Dawson said.
In future work, the researchers will investigate whether ovarian cancer cells have some natural inclination towards this uniquely more aggressive behavior in softer environments.
“We’re trying to find out whether there is some internal programming that leads to this aggressive behavior,” Dawson said.
This research is supported by the National Science Foundation under award number 1032527, and the Georgia Tech and Emory Center for Regenerative Medicine under award number 1411304. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Daniel J. McGrail, et al., “The malignancy of metastatic ovarian cancer cells is increased on soft matrices through a mechanosensitive Rho-ROCK pathway.” (Journal of Cell Science, 2014). http://dx.doi.org/10.1242/?jcs.144378
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]]>Ten of the 40 companies are either graduates or current members of the Advanced Technology Development Center (ATDC), Georgia Tech’s incubator for technology companies. Nine companies, including two of the ATDC firms, are headed by Georgia Tech alumni. Other companies have connections through a student founder, faculty advisor or research collaboration.
The ATDC graduates are Accelarad, Emcien Corporation, Innovolt, MessageGears and Patientco. Current ATDC companies include Azalea Health, Rigor, Sensiotec, SoftWear Automation and Springbot. The “Top 40 Innovative Technology” companies showcased their products and services at the TAG Georgia Technology Summit held in March at the Cobb Galleria Center.
“Through the accomplishments of alumni entrepreneurs, the assistance of ATDC and other connections, Georgia Tech is contributing to the state’s economy through the development of innovative technology companies,” said Stephen Fleming, Georgia Tech vice president and executive director of the Enterprise Innovation Institute which oversees the ATDC. “The companies selected by TAG demonstrate the broad-based impact Georgia Tech has on the state’s technology community.”
The 40 companies chosen for the honor were selected from among 120 applications submitted by companies from across Georgia.
“The 2014 Top 40 finalists are an elite group of innovators who represent the very best of Georgia’s technology community,” Tino Mantella, president and CEO of TAG, said in the organization’s news release on the companies. “The 2014 Top 40 finalists are shining examples of what makes our state such a hotbed for technology, and we applaud them for standing out as leaders in Georgia’s technology community.”
In addition to the ATDC incubator, Georgia Tech also operates the VentureLab program to help researchers spin off companies from the Institute’s research program. Other efforts aimed at startup companies include Flashpoint, an accelerator for technology companies, and the NSF I-Corps program, which helps faculty develop companies from research funded by the National Science Foundation.
The complete list of innovative companies is available on the TAG website. http://www.tagonline.org/news-press/tag-names-top-40-innovative-technology-companies-in-georgia-march/
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]]>The atom-thin sheet of carbon is touted not just for its electrical properties but also for its physical strength and flexibility. The bonds between carbon atoms are well known as the strongest in nature, so a perfect sheet of graphene should withstand just about anything. Reinforcing composite materials is among the material’s potential applications.
But materials scientists know perfection is hard to achieve. Researchers Jun Lou at Rice and Ting Zhu at Georgia Tech have measured the fracture toughness of imperfect graphene for the first time and found it to be somewhat brittle. While it's still very useful, graphene is really only as strong as its weakest link, which they determined to be "substantially lower" than the intrinsic strength of graphene.
“Graphene has exceptional physical properties, but to use it in real applications, we have to understand the useful strength of large-area graphene, which is controlled by the fracture toughness,” said Zhu, who is an associate professor in the Woodruff School of Mechanical Engineering at Georgia Tech.
The researchers reported in the journal Nature Communications the results of tests in which they physically pulled graphene apart to see how much force it would take. Specifically, they wanted to see if graphene follows the century-old Griffith theory that quantifies the useful strength of brittle materials.
It does, said Lou. "Remarkably, in this case, thermodynamic energy still rules," he said.
Imperfections in graphene drastically lessen its strength – with an upper limit of about 100 gigapascals (GPa) for perfect graphene previously measured by nanoindentation – according to physical testing at Rice and molecular dynamics simulations at Georgia Tech. That's important for engineers to understand as they think about using graphene for flexible electronics, composite material and other applications in which stresses on microscopic flaws could lead to failure.
The Griffith criterion developed by a British engineer during World War I describes the relationship between the size of a crack in a material and the force required to make that crack grow. Ultimately, A.A. Griffith hoped to understand why brittle materials fail.
Graphene, it turns out, is no different from the glass fibers Griffith tested.
"Everybody thinks the carbon-carbon bond is the strongest bond in nature, so the material must be very good," Lou said. "But that's not true anymore, once you have those defects. The larger the sheet, the higher the probability of defects. That's well known in the ceramic community."
A defect can be as small as an atom missing from the hexagonal lattice of graphene. But for a real-world test, the researchers had to make a defect of their own – a pre-crack – they could actually see. "We know there will be pinholes and other defects in graphene," he said. "The pre-crack overshadows those defects to become the weakest spot – so I know exactly where the fracture will happen when we pull it.
"The material resistance to the crack growth – the fracture toughness – is what we're measuring here, and that's a very important engineering property," he said.
Just setting up the experiment required several years of work to overcome technical difficulties, Lou said. To suspend it on a tiny cantilever spring stage similar to an atomic force microscopy (AFM) probe, a graphene sheet had to be clean and dry so it would adhere (via van der Waals force) to the stage without compromising the stage movement necessary for the testing. Once mounted, the researchers used a focused ion beam to cut a pre-crack less than 10 percent of the width into the microns-wide section of suspended graphene. Then they pulled the graphene in half, measuring the force required.
While the Rice team was working on the experiment, Zhu and his team performed computer simulations to understand the entire fracture process.
“We can directly simulate the whole deformation process by tracking the motion and displacement with atomic-scale resolution in fairly large samples so our results can be directly correlated with the experiment,” said Zhu. “The modeling is tightly coupled with the experiments.”
The combination of modeling and experiment provides a level of detail that allowed the researchers to better understand the fracture process – and the tradeoff between toughness and strength in the graphene. What the scientists have learned in the research points out the importance of fabricating high quality graphene sheets without defects – which could set the stage for fracture.
“Understanding the tradeoff between strength and toughness provides important insights for the future utilization of graphene in structural and functional applications,” Zhu added. “This research provides a foundational framework for further study of the mechanical properties of graphene.”
Lou said the techniques they used should work for any two-dimensional material. "It's important to understand how defects will affect the handling, processing and manufacture of these materials," he said. "Our work should open up new directions for testing the mechanical properties of 2-D materials."
Co-authors of the paper are graduate students Peng Zhang, Lulu Ma, Phillip Loya and Yongji Gong, and former graduate students Cheng Peng and Jiangnan Zhang, all at Rice; Feifei Fan and Zhi Zeng, graduate students at Georgia Tech; Zheng Liu, an assistant professor at Nanyang Technological University, Singapore, with a complimentary appointment at Rice; Pulickel Ajayan, Rice's Benjamin M. and Mary Greenwood Anderson Professor in Materials Science and Nanoengineering and of Chemistry; and Xingxiang Zhang, a professor at Tianjin Polytechnic University, China.
Lou is an associate professor of Materials Science and Nanoengineering and of Chemistry at Rice. The Welch Foundation, the National Science Foundation, the U.S. Office of Naval Research and the Korean Institute of Machinery and Materials supported the research.
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]]>The study confirms laboratory experiments showing that the behavior of reef fishes can be seriously affected by increased carbon dioxide concentrations in the ocean. The new study is the first to analyze the sensory impairment of fish from CO2 seeps, where pH is similar to what climate models forecast for surface waters by the turn of the century.
"These results verify our laboratory findings," said Danielle Dixson, an assistant professor in the School of Biology at the Georgia Institute of Technology in Atlanta. "There's no difference between the fish treated with CO2 in the lab in tests for chemical senses versus the fish we caught and tested from the CO2 reef."
The research was published in the April 13 Advance Online Publication of the journal Nature Climate Change. Philip Munday, from James Cook University in Australia, was the study's lead author. The work was supported by the Australian Institute for Marine Science, a Grant for Research and Exploration by the National Geographic Society, and the ARC Centre of Excellence for Coral Reef Studies.
The pH of normal ocean surface water is around 8.14. The new study examined fish from so-called bubble reefs at a natural CO2 seep in Papua New Guinea, where the pH is 7.8 on average. With today's greenhouse gas emissions, climate models forecast pH 7.8 for ocean surface waters by 2100, according to theIntergovernmental Panel on Climate Change (IPCC).
"We were able to test long-term realistic effects in this environment," Dixson said. "One problem with ocean acidification research is that it's all laboratory based, or you're testing something that's going to happen in a 100 years with fish that are from the present day, which is not actually accurate."
Previous research had led to speculation that ocean acidification might not harm fish if they could buffer their tissues in acidified water by changing their bicarbonate levels. Munday and Dixson were the first to show that fishes' sensory systems are impaired under ocean acidification conditions in the laboratory.
"They can smell but they can't distinguish between chemical cues," Dixson said.
Carbon dioxide released into the atmosphere is absorbed into ocean waters, where it dissolves and lowers the pH of the water. Acidic waters affect fish behavior by disrupting a specific receptor in the nervous system, called GABAA, which is present in most marine organisms with a nervous system. When GABAA stops working, neurons stop firing properly.
Coral reef habitat studies have found that CO2-induced behavioral changes, similar to those observed in the new study, increase mortality from predation by more than fivefold in newly settled fish.
Fish can smell a fish that eats another fish and will avoid water containing the scent. In Dixson's laboratory experiments, control fish given the choice between swimming in normal water or water spiked with the smell of a predator will choose the normal water. But fish raised in water acidified with carbon dioxide will choose to spend time in the predator-scented water.
Juvenile fish living at the carbon dioxide seep and brought onto a boat for behavior testing had nearly the identical predator sensing impairment as juvenile fish reared at similar CO2 levels in the lab, the new study found.
The fish from the bubble reef were also bolder. In one experiment, the team measured how far the fish roamed from a shelter and then created a disturbance to send the fish back to the shelter. Fish from the CO2 seep emerged from the shelter at least six times sooner than the control fish after the disturbance.
Despite the dramatic effects of high CO2 on fish behaviors, relatively few differences in species richness, species composition and relative abundances of fish were found between the CO2 seep and the control reef.
"The fish are metabolically the same between the control reef and the CO2 reef," Dixson said. "At this point, we have only seen effects on their behavior."
The researchers did find that the number of large predatory fishes was lower at the CO2 seep compared to the control reef, which could offset the increased risk of mortality due to the fishes' abnormal behavior, the researchers said.
In future work, the research team will test if fish could adapt or acclimate to acidic waters. They will first determine if the fish born at the bubble reef are the ones living there as adults, or if baby fish from the control reef are swimming to the bubble reef.
"Whether or not this sensory effect is happening generationally is something that we don't know," Dixson said.
The results do show that what Dixson and colleagues found in the lab matches with what is seen in the field.
"It's a step in the right direction in terms of answering ocean acidification problems." Dixson said. "The alternative is just to wait 100 years. At least now we might prepare for what might be happening."
This research is supported by the Australian Institute for Marine Science, a Grant for Research and Exploration by the National Geographic Society, and the ARC Centre of Excellence for Coral Reef Studies. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Philip L. Munday, et al., "Behavioural impairment in reef fishes caused by ocean acidification at CO2 seeps." (Nature Climate Change, April 2014). http://dx.doi.org/10.1038/NCLIMATE2195
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]]>The study confirms laboratory experiments showing that the behavior of reef fishes can be seriously affected by increased carbon dioxide concentrations in the ocean. The new study is the first to analyze the sensory impairment of fish from CO2 seeps, where pH is similar to what climate models forecast for surface waters by the turn of the century.
]]>404-385-1933
]]>A core technological hurdle in this field involves the electrical power requirements of computing hardware. Although a human brain functions on a mere 20 watts of electrical energy, a digital computer that could approximate human cognitive abilities would require tens of thousands of integrated circuits (chips) and a hundred thousand watts of electricity or more – levels that exceed practical limits.
The Georgia Tech roadmap proposes a solution based on analog computing techniques, which require far less electrical power than traditional digital computing. The more efficient analog approach would help solve the daunting cooling and cost problems that presently make digital neuromorphic hardware systems impractical.
"To simulate the human brain, the eventual goal would be large-scale neuromorphic systems that could offer a great deal of computational power, robustness and performance," said Jennifer Hasler, a professor in the Georgia Tech School of Electrical and Computer Engineering (ECE), who is a pioneer in using analog techniques for neuromorphic computing. "A configurable analog-digital system can be expected to have a power efficiency improvement of up to 10,000 times compared to an all-digital system."
Hasler and a former student recently published a detailed plan that describes the development of computer systems capable of human-like cognition. The paper, "Finding a Roadmap to Achieve Large Neuromorphic Hardware Systems" by Hasler and Bo Marr, was published in the September 2013 edition of the journal Frontiers in Neuroscience.
"To my knowledge, this is the first time a detailed neuromorphic roadmap has been attempted," said Hasler. "We describe specific computational techniques could offer real progress in neuromorphic systems."
Unlike digital computing, in which computers can address many different applications by processing different software programs, analog circuits have traditionally been hard-wired to address a single application. For example, cell phones use energy-efficient analog circuits for a number of specific functions, including capturing the user's voice, amplifying incoming voice signals, and controlling battery power.
Because analog devices do not have to process binary codes as digital computers do, their performance can be both faster and much less power hungry. Yet traditional analog circuits are limited because they're built for a specific application, such as processing signals or controlling power. They don't have the flexibility of digital devices that can process software, and they're vulnerable to signal disturbance issues, or noise.
In recent years, Hasler has developed a new approach to analog computing, in which silicon-based analog integrated circuits take over many of the functions now performed by familiar digital integrated circuits. These analog chips can be quickly reconfigured to provide a range of processing capabilities, in a manner that resembles conventional digital techniques in some ways.
Over the last several years, Hasler and her research group have developed devices called field programmable analog arrays (FPAA). Like field programmable gate arrays (FPGA), which are digital integrated circuits that are ubiquitous in modern computing, the FPAA can be reconfigured after it's manufactured – hence the phrase "field-programmable."
Hasler and Marr's 29-page paper traces a development process that could lead to the goal of reproducing human-brain complexity. The researchers investigate in detail a number of intermediate steps that would build on one another, helping researchers advance the technology sequentially.
For example, the researchers discuss ways to scale energy efficiency, performance and size in order to eventually achieve large-scale neuromorphic systems. The authors also address how the implementation and the application space of neuromorphic systems can be expected to evolve over time.
"A major concept here is that we have to first build smaller systems capable of a simple representation of one layer of human brain cortex," Hasler said. "When that system has been successfully demonstrated, we can then replicate it in ways that increase its complexity and performance."
Among neuromorphic computing's major hurdles are the communication issues involved in networking integrated circuits in ways that could replicate human cognition. In their paper, Hasler and Marr emphasize local interconnectivity to reduce complexity. Moreover, they argue it's possible to achieve these capabilities via purely silicon-based techniques, without relying on novel devices that are based on other approaches.
Commenting on the recent publication, Alice C. Parker, a professor of electrical engineering at the University of Southern California, said, "Professor Hasler's technology roadmap is the first deep analysis of the prospects for large scale neuromorphic intelligent systems, clearly providing practical guidance for such systems, with a nearer-term perspective than our whole-brain emulation predictions. Her expertise in analog circuits, technology and device models positions her to provide this unique perspective on neuromorphic circuits."
Eugenio Culurciello, an associate professor of biomedical engineering at Purdue University, commented, "I find this paper to be a very accurate description of the field of neuromorphic data processing systems. Hasler's devices provide some of the best performance per unit power I have ever seen and are surely on the roadmap for one of the major technologies of the future."
Said Hasler: "In this study, we conclude that useful neural computation machines based on biological principles – and potentially at the size of the human brain -- seems technically within our grasp. We think that it's more a question of gathering the right research teams and finding the funding for research and development than of any insurmountable technical barriers."
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]]>In a universe with tens of billions of galaxies, how would we see it? What would such a beacon look like? And how would we distinguish it from other bright, monumental intergalactic events, such as supernovas?
"Black holes by themselves do not emit light," said Tamara Bogdanovic, an assistant professor of physics at the Georgia Institute of Technology. "Our best chance to discover them in distant galaxies is if they interact with the stars and gas that are around them."
In recent decades, with improved telescopes and observational techniques designed to repeatedly survey the vast numbers of galaxies in the sky, scientists noticed that some galaxies that previously looked inactive would suddenly light up at their very center.
"This flare of light was found to have a characteristic behavior as a function of time. It starts very bright and its luminosity then decreases in time in a particular way," she explained. "Astronomers have identified those as galaxies where a central black hole just disrupted and 'ate' a star. It's like a black hole putting up a sign that says 'Here I am.'"
Using a mix of theoretical and computer-based approaches, Bogdanovic tries to predict the dynamics of events such as the black-hole-devouring-star scenario described above, also known as a "tidal disruption." Such events would have a distinct signature to someone analyzing data from a ground-based or space-based observatory.
Using National Science Foundation-funded supercomputers at the Texas Advanced Computing Center (Stampede) and the National Institute for Computational Sciences (Kraken), Bogdanovic and her collaborators recently simulated the dynamics of these super powerful forces and charted their behavior using numerical models.
Tidal disruptions are relatively rare cosmic occurrences. Astrophysicists have calculated that a Milky Way-like galaxy stages the disruption of a star only once in about 10,000 years. The luminous flare of light, on the other hand, can fade away in only a few years. Because it is such a challenge to pinpoint tidal disruptions in the sky, astronomical surveys that monitor vast numbers of galaxies simultaneously are crucial.
Huge difference
So far, only a few dozen of these characteristic flare signatures have been observed and deemed "candidates" for tidal disruptions. But with data from PanSTARRS, Galex, the Palomar Transient Factory and other upcoming astronomical surveys becoming available to scientists, Bogdanovic believes this situation will change dramatically.
"As opposed to a few dozen that have been found over the past 10 years, now imagine hundreds per year--that's a huge difference!" she said. "It means that we will be able to build a varied sample of stars of different types being disrupted by supermassive black holes."
With hundreds of such events to explore, astrophysicists' understanding of black holes and the stars around them would advance by leaps and bounds, helping determine some key aspects of galactic physics.
"A diversity in the type of disrupted stars tells us something about the makeup of the star clusters in the centers of galaxies," Bodganovic said. "It may give us an idea about how many main sequence stars, how many red giants, or white dwarf stars are there on average."
Tidal disruptions also tell us something about the population and properties of supermassive black holes that are doing the disrupting.
"We use these observations as a window of opportunity to learn important things about the black holes and their host galaxies," she continued. "Once the tidal disruption flare dims below some threshold luminosity that can be seen in observations, the window closes for that particular galaxy."
Role of supercomputer
In a recent paper submitted to the Astrophysical Journal, Bogdanovic, working with Roseanne Cheng (Center for Relativistic Astrophysics at Georgia Tech) and Pau Amaro-Seoane (Albert Einstein Institute in Potsdam, Germany), considered the tidal disruption of a red giant star by a supermassive black hole using computer modeling.
The paper comes on the heels of the discovery of a tidal disruption event in which a black hole disrupted a helium-rich stellar core, thought to be a remnant of a red giant star, named PS1-10jh, 2.7 billion light years from Earth.
The sequence of events they described aims to explain some unusual aspects of the observational signatures associated with this event, such as the absence of the hydrogen emission lines from the spectrum of PS1-10jh.
As a follow-up to this theoretical study, the team has been running simulations on Kraken and Stampede, as well as the Georgia Tech's high performance computing clusters. The simulations reconstruct the chain of events by which a stellar core, similar to the remnant of a tidally disrupted red giant star, might evolve under the gravitational tides of a massive black hole.
"Calculating the messy interplay between hydrodynamics and gravity is feasible on a human timescale only with a supercomputer," Cheng said. "Because we have control over this virtual experiment and can repeat it, fast forward, or rewind as needed, we can examine the tidal disruption process from many perspectives. This in turn allows us to determine and quantify the most important physical processes at play."
The research shows how supercomputer simulations complement and constrain theory and observation.
"There are many situations in astrophysics where we cannot get insight into a sequence of events that played out without simulations. We cannot stand next to the black hole and look at how it accretes gas. So we use simulations to learn about these distant and extreme environments," Bogdanovic said.
One of Bogdanovic's goals is to use the knowledge gained from simulations to decode the signatures of observed tidal disruption events.
"The most recent data on tidal disruption events is already outpacing theoretical understanding and calling for the development of a new generation of models," she explained. "The new, better quality data indicates that there is a great diversity among the tidal disruption candidates. This is contrary to our perception, based on earlier epochs of observation, that they are a relatively uniform class of events. We have yet to understand what causes these differences in observational appearance, and computer simulations are guaranteed to be an important part of this journey."
-- Written by Aaron Dubrow of the National Science Foundation.
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]]>To detect the fake drugs, researchers at the Georgia Institute of Technology developed a sophisticated approach using mass spectrometry to quickly assess suspected counterfeit drugs and then characterize their chemical composition. The study’s results highlight a growing concern for women’s health in developing nations.
“A woman who does not want to get pregnant and takes these emergency contraceptives will get pregnant,” said Facundo M. Fernández, a professor in the School of Chemistry and Biochemistry, whose lab investigated the contraceptives.
The study was sponsored by the ACT Consortium through a grant from the Bill and Melinda Gates Foundation. The study was published April 18 in the journal PLOS ONE.
Drugs are considered fake or falsified when someone makes a pirate copy of copies a patented drug, with criminal intent. Recent research has found that falsified drugs are a major problem in developing countries. Falsified emergency contraceptives have been reported in Nigeria, Ghana, Kenya, Angola, South America and even the United States. Fake drug manufacturers will copy everything from the pill to the package.
Just as concerning as counterfeit medications are other poor quality medications, such as degraded or substandard drugs. Degraded drugs were once good quality, but lost their efficacy over time, for example after prolonged exposure to the sun in an open air market.
Substandard drugs are made by an approved factory, but they don’t contain the right active ingredient, contain less active ingredient than they should, or might not dissolve properly. These pills either result from factory error or negligence.
Falsified drugs are the most worrisome, because they may not contain the expected active ingredient, or they may contain the wrong ingredients, including toxic compounds.
In the survey of emergency contraceptives from Peru, the researchers found that seven of the 25 batches analyzed had inadequate release of the active ingredient (levonorgestrel). One batch had no detectable level of the active ingredient.
“We detected that the active ingredient was not there in one batch, instead those samples had a drug called sulfamethoxazole,” Fernandez said. “It’s a very common antibiotic. It can cause serious adverse reactions in some patients.”
For the study, samples of emergency contraceptives were purchased at 15 pharmacies and distributors in Lima, Peru, with 60 tables purchased per sample. Tablets were collected from 25 different product batches encompassing 20 brands labeled as manufactured in nine countries (Argentina, Chile, China, Colombia, Hungary, India, Pakistan, Peru and Uruguay).
Analyzing these samples is time consuming and costly with standard tools, so Fernandez’s lab developed a method for a quick screen to identify problematic pills. The first-pass screen then allows the researchers to focus a sophisticated analysis on drugs that are suspected fakes. The drugs that pass the screen will still be closely analyzed, but after the suspected fakes.
Fernandez’s lab used a tool called ambient mass spectrometry. Scientists in the lab grasp a tablet with a pair of tweezers and swing it front of the instrument to get a real-time signature of the tablet’s chemical composition.
“Very quickly we pick out which ones are the problems,” Fernandez said.
Their analysis is a tiered-approach. First they look for the presence and identity of the active ingredient. Then they look to see if the right amount is present. Then they test if the pill properly dissolves. Many sophisticated fake pills might pass all these tests, so the scientists also look at the filler in the pills, known as the excipients, such as lactose and cellulose.
“Many fakes are very sophisticated. They have the right active ingredient and they may even have the right amount, but the excipients or coatings may not be the right ones,” Fernandez said.
His students have processed thousands of samples and can spot many fake pills before performing the analysis.
“They touch it a bit with their nails and they try to cut into it and they know it’s like a rock, just way too hard,” Fernandez said. “The tablets are sometimes so hard that they won’t dissolve. That’s something that you pick up pretty quickly.”
Fernandez’s lab is working to make these mass spectrometry tools portable so that researchers might be able to do these analyses in the field.
“You really want to catch these fakes early, at the customs level or at the distribution center level,” Fernandez said. “You don’t want to wait for this to get to the pharmacy or for somebody to report it.”
This research is supported by the Bill and Melinda Gates Foundation. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.
CITATION: María Eugenia Monge, et al., “A Tiered Analytical Approach for Investigating Poor Quality Emergency Contraceptives.” (PLOS ONE, April 2014) http://dx.plos.org/10.1371/journal.pone.0095353
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]]>Georgia Tech is one of only six universities – Carnegie Mellon University, North Carolina State University, Purdue University, Stanford University and the University of Utah are the others – to be included in both the 2014 and 2002 versions of the report.
“One of the more heartening aspects of the Georgia Tech story is that the institution has largely stayed true to the aspirations of the founders back in the 19th century,” the Innovation U 2.0 report says. “Those aspirations were to develop a first class technological university, one that combined excellence in academic education with a hand ‘in the shop,’ and one that enabled Georgia to create a modern economy.”
The report goes on to note that Georgia Tech’s vision is more than just aspiration.
“All of those things have been achieved and the bar continues to be raised as its impact is felt throughout the world,” the report continues. “Georgia Tech is one of the great American stories [of how] sustained inspired leadership, diligence in execution, and an ever-expanding vision and culture can accomplish amazing things.”
Innovation U 2.0 quotes from Georgia Tech’s strategic plan, which was approved in 2010, and cites examples of how it has been implemented:
The Enterprise Innovation Institute (EI2), home to the majority of Georgia Tech’s economic development and business assistance programs, gets special attention in the report.
“The programs are quite diverse in terms of clients or participants, physical and organizational location, and collectively they encompass a continuum that extends from early technology and venture development to established firms with significant history,” it says of EI2. “These programs leverage a mix of state, federal, and private sector funding to enhance economic development in the state of Georgia. Conceptually, the programs and clients are all united by the emphases on innovation and entrepreneurship, and the structure enables program leadership to share best practices and policies across the heterogeneous mix.”
Summing up EI2, Innovation U 2.0 concludes: “Among the cases in this volume, [Georgia Tech's EI2] is probably the most novel organizational solution to the inherent diversity of activities that fall under the labels of innovation and entrepreneurship, and one that seems to have enough authority to give it a fair trial.”
Technology Square was under construction when the 2002 Innovation U report was done. The 2014 version notes the impact of the midtown development, which is home to not only EI2, but also the Scheller College of Business, Georgia Tech Professional Education, Georgia Tech Hotel and Conference Center, Technology Square Research Building, and Barnes & Noble Georgia Tech Bookstore.
“Technology Square can be seen as an intentional design effort by Georgia Tech to foster inter-sector engagement by creating a mixed-use district,” says the report. “Technology Square is still only 10 years old. It is early and the aspiration is that this area will evolve into a high tech bazaar with a large variety and number of entities involved.”
Innovation U 2.0 was produced by Louis G. Tornatzky, who recently retired from California Polytechnic State University, and by Elaine C. Rideout of North Carolina State University. The complete report is available online at (www.innovation-u.com).
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]]>The current design integrates nanotechnology and radio-frequency identification (RFID) capabilities into a small working prototype. An array of sensors uses carbon nanotubes and other nanomaterials to detect specific chemicals, while an RFID integrated circuit informs users about the presence and concentrations of those vapors at a safe distance wirelessly.
Because it is based on programmable digital technology, the RFID component can provide greater security, reliability and range – and much smaller size – than earlier sensor designs based on non-programmable analog technology. The present GTRI prototype is 10 centimeters square, but further designs are expected to squeeze a multiple-sensor array and an RFID chip into a one-millimeter-square device printable on paper or on flexible, durable substrates such as liquid crystal polymer.
“Production of these devices promises to become so inexpensive that they could be used by the thousands in the field to look for telltale chemicals such as ammonia, which is associated with explosives," said Xiaojuan (Judy) Song, a GTRI senior research scientist who is principal investigator on the project. "This remote capability would inform soldiers or first responders about numerous hazards before they encountered them."
Wireless sensors could also be valuable for identifying and understanding air pollution, she said. Inexpensive sensors that detect ammonia and nitrogen oxides (NOx) could be fielded in large numbers, giving scientists increased knowledge of the location and intensity of pollutants.
The availability of such chips might also help companies detect food spoilage. And healthcare facilities could benefit, as the presence of telltale chemicals informed caregivers of patient conditions and needs.
The present prototype contains three sensors along with an RFID chip. Future devices for field use might contain a much larger number of sensors based on various nanomaterials – including carbon nanotubes, graphene and molybdenum disulfide – depending on the types of chemicals to be detected.
"In general, having an extensive sensing array is the best approach," Song said. "For real-world applications, a variety of sensors offers better functionality, because they can work together to produce a more detailed and reliable picture of the chemical environment."
The RFID component in the GTRI device makes use of the 5.8 gigahertz (GHz) radio frequency, one of several radio bands reserved for industrial, scientific and medical (ISM) purposes. The GTRI component is believed to be the first RFID system that exploits this frequency.
The advantage of 5.8 GHz technology is that it will let RFID tags be made extremely small – in the area of one centimeter square, said Christopher Valenta, a GTRI research engineer who is co-principal investigator on the project. He explained that the digital transmission of data from RFID-based sensors does a much better job than earlier analog techniques based on interpretation of radio-frequency waveforms.
Specifically, digital signaling with 5.8 GHz RFID offers:
The GTRI team is currently gearing up to design a very small, 5.8 GHz RFID component. After fabrication and testing, the chip could be manufactured in large numbers inexpensively.
"It might take $400,000 to design and fabricate that first RFID chip, but all the subsequent copies might cost only a few pennies," said Valenta, who is a Ph.D. candidate in the School of Electrical and Computer Engineering.
The GTRI team successfully tested its prototype sensing system in a demonstration designed to resemble an airport checkpoint. The sensor array detected the targeted chemical despite emersion in a complex chemical environment, and the RFID component was able to transmit the sensors' readings.
The present GTRI prototype is semi-passive, so it requires power from an incoming signal beam in order to send data back to a remote reading device. However, future sensing devices might exploit ambient energy from solar or vibrational sources that would let them work at longer ranges with greater sensitivity.
The team is continuing to work on the important task of developing pattern recognition software that will support effective functioning of the sensor array.
"The prototype 5.8 GHz wireless sensing system promises to be flexible and highly scalable," Valenta said. "An advanced design might include an array of 10 or more different sensors, with electronics that could utilize those sensors to perform 25 different jobs, and yet still be tiny, robust and inexpensive."
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]]>Computational and experimental studies show that the superlattice structures, which are self-assembled from smaller clusters of silver nanoparticles and organic protecting molecules, form in layers with the hydrogen bonds between their components serving as “hinges” to facilitate the rotation. Movement of the “gears” is related to another unusual property of the material: increased pressure on the superlattice softens it, allowing subsequent compression to be done with significantly less force.
Materials containing the gear-like nanoparticles – each composed of nearly 500 atoms – might be useful for molecular-scale switching, sensing and even energy absorption. The complex superlattice structure is believed to be among the largest solids ever mapped in detail using a combined X-ray and computational techniques.
“As we squeeze on this material, it gets softer and softer and suddenly experiences a dramatic change,” said Uzi Landman, a Regents’ and F.E. Callaway professor in the School of Physics at the Georgia Institute of Technology. “When we look at the orientation of the microscopic structure of the crystal in the region of this transition, we see that something very unusual happens. The structures start to rotate with respect to one another, creating a molecular machine with some of the smallest moving elements ever observed.”
The gears rotate as much as 23 degrees, and return to their original position when the pressure is released. Gears in alternating layers move in opposite directions, said Landman, who is director of the Center for Computational Materials Science at Georgia Tech.
Supported by the Air Force Office of Scientific Research and the Office of Basic Energy Sciences in the Department of Energy, the research was reported April 6 in the journal Nature Materials. Researchers from Georgia Tech and the University of Toledo collaborated on the project.
The research studied superlattice structures composed of clusters with cores of 44 silver atoms each. The silver clusters are protected by 30 ligand molecules of an organic material – mercaptobenzoic acid (p-MBA) – that includes an acid group. The organic molecules are attached to the silver by sulfur atoms.
“It’s not the individual atoms that form the superlattice,” explained Landman. “You actually make the larger structure from clusters that are already crystallized. You can make an ordered array from those.”
In solution, the clusters assemble themselves into the larger superlattice, guided by the hydrogen bonds, which can only form between the p-MBA molecules at certain angles.
“The self-assembly process is guided by the desire to form hydrogen bonds,” Landman explained. “These bonds are directional and cannot vary significantly, which restricts the orientation that the molecules can have.”
The superlattice was studied first using quantum-mechanical molecular dynamics simulations conducted in Landman’s lab. The system was also studied experimentally by a research group headed by Terry Bigioni, an associate professor in the Department of Chemistry and Biochemistry at the University of Toledo.
The unusual behavior occurred as the superlattice was being compressed using hydrostatic techniques. After the structure had been compressed by about six percent of its volume, the pressure required for additional compression suddenly dropped significantly. The researchers discovered that the drop occurred when the nanocrystal components rotated, layer-by-layer, in opposite directions.
Just as the hydrogen bonds direct how the superlattice structure is formed, so also do they guide how the structure moves under pressure.
“The hydrogen bond likes to have directionality in its orientation,” Landman explained. “When you press on the superlattice, it wants to maintain the hydrogen bonds. In the process of trying to maintain the hydrogen bonds, all the organic ligands bend the silver cores in one layer one way, and those in the next layer bend and rotate the other way.”
When the nanoclusters move, the structure pivots about the hydrogen bonds, which act as “molecular hinges” to allow the rotation. The compression is possible at all, Landman noted, because the crystalline structure has about half of its space open.
The movement of the silver nanocrystallites could allow the superlattice material to serve as an energy-absorbing structure, converting force to mechanical motion. By changing the conductive properties of the silver superlattice, compressing the material could also allow it be used as molecular-scale sensors and switches.
The combined experimental and computation study makes the silver superlattice one of the most thoroughly studied materials in the world.
“We now have complete control over a unique material that by its composition has a diversity of molecules,” Landman said. “It has metal, it has organic materials and it has a stiff metallic core surrounded by a soft material.”
For the future, the researchers plan additional experiments to learn more about the unique properties of the superlattice system. The unique system shows how unusual properties can arise when nanometer-scale systems are combined with many other small-scale units.
“We make the small particles, and they are different because small is different,” said Landman. “When you put them together, having more of them is different because that allows them to behave collectively, and that collective activity makes the difference.”
In addition to those already mentioned, Georgia Tech co-authors included research scientist Bokwon Yoon – the paper’s first author – and senior research scientists W.David Luedtke, Robert Barnett and Jianping Gao. Co-authors from the University of Toledo include Anil Desireddy and Brian E. Conn.
This research was supported by the Air Force Office of Scientific Research (AFOSR), and by the Office of Basic Energy Sciences of the U.S. Department of Energy (DOE) under Contract FG05-86ER45234. Any conclusions or opinions expressed are those of the authors and do not necessarily represent the official views of the AFOSR or the DOE.
CITATION: Bokwon Yoon, et al., “Hydrogen-bonded structure and mechanical chiral response of a silver nanoparticle superlattice.” (Nature Materials, 2014). http://dx.doi.org/ 10.1038/NMAT3923.
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]]>Researchers have shown that a process called DNA methylation can shield duplicate genes from being removed from the genome during natural selection. The redundant genes survive and are shaped by evolution over time, giving birth to new cellular functions.
“This is the first study to show explicitly how the processes of DNA methylation and duplicate gene evolution are related,” said Soojin Yi, an associate professor in the School of Biology and the Parker H. Petit Institute for Bioengineering and Bioscience at the Georgia Institute of Technology.
The study was sponsored by the National Science Foundation (NSF) and was scheduled to be published the week of April 7 in the Online Early Edition of the journal Proceedings of the National Academy of Sciences (PNAS).
At least half of the genes in the human genome are duplicates. Duplicate genes are not only redundant, but they can be bad for cells. Most duplicate genes accumulate mutations at high rates, which increases the chance that the extra gene copies will become inactive and lost over time due to natural selection.
The new study found that soon after some duplicate genes form, small hydrocarbons called methyl groups attach to a duplicate gene’s regulatory region and block the gene from turning on.
When a gene is methylated, it is shielded from natural selection, which allows the gene to hang around in the genome long enough for evolution to find a new use for it. Some young duplicate genes are silenced by methylation almost immediately after being formed, the study found.
“What we have done is the first step in the process to show that young gene duplicates seems to be heavily methylated,” Yi said.
The study showed that the average level of DNA methylation on the duplicate gene regulatory region is significantly negatively correlated with evolutionary time. So, younger duplicate genes have high levels of DNA methylation.
For about three-quarters of the duplicate gene pairs studied, the gene in a pair that was more methylated was always more methylated across all 10 human tissues studied, said Thomas Keller, a post-doctoral fellow at Georgia Tech and the study’s first author.
“For the tissues that we examined, there was remarkable consistency in methylation when we looked at duplicate gene pairs,” Keller said.
The computational study constructed a dataset of all human gene duplicates by comparing each sequence against every other sequence in the human genome. DNA methylation data was then obtained for the 10 different human tissues. The researchers used computer models to analyze the links between DNA methylation and gene duplication.
The human brain is one example of a tissue for which gene duplication has been particularly important for its evolution. In future studies, the researchers will examine the link between epigenetic evolution and human brain evolution.
This research is supported by the National Science Foundation (NSF) under award numbers BCS-1317195 and MCB-0950896. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.
CITATION: Thomas E. Keller, et al., “DNA Methylation and Evolution of Duplicate Genes.” (PNAS, April 2014). http://www.dx.doi.org/10.1073/pnas.1321420111
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]]>These T-cells use a complex process to recognize the foreign pathogens and diseased cells. In a paper published this week in the journal Cell, researchers add a new level of understanding to that process by describing how the T-cell receptors (TCR) use mechanical contact – the forces involved in their binding to the antigens – to make decisions about whether or not the cells they encounter are threats.
“This is the first systematic study of how T-cell recognition is affected by mechanical force, and it shows that forces play an important role in the functions of T-cells,” said Cheng Zhu, a Regents’ professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “We think that mechanical force plays a role in almost every step of T-cell biology.”
The researchers, who were supported by the National Institutes of Health, made their discoveries using a tiny sensor based on a single red blood cell, and a new technique for detecting calcium ions emitted by the T-cells as part of the signaling process. They independently studied the binding of antigens to more than a hundred individual T-cells, measuring the forces involved in the binding and the lifetimes of the bonds. That information was then correlated to the calcium signaling they observed.
Among the findings, the researchers learned that interactions between the TCRs and agonist peptide-major histocompatibility complexes (MHC) form catch bonds that become stronger with the application of additional force to initiate intracellular signaling. Less active MHC complexes form slip bonds that weaken with force and don’t initiate signaling. Overall, they found that the signaling outcome of an interaction between an antigen and a TCR depends on the magnitude, duration, frequency and timing of the force application.
“Force adds another dimension to interactions with T-cells,” Zhu explained. “Antigens that have a bond lifetime that is prolonged by force would have a higher likelihood of triggering signaling. Repeat engagements and lifetime accumulations play a role, and the decision to signal is usually made based on the accumulation of actions, not a single action.”
He compared the force component of T-cell activation to multiple steps needed to enter a person’s office inside a secured building. A key card and a personal identification number may first be necessary to enter the building, while an ordinary key might then be needed to get into a specific office. Requiring both recognition of an antigen and specific level of mechanical force may help the T-cell avoid activating when it shouldn’t, Zhu said.
Zhu compared the accumulation of bonds to the punches that a boxer sustains during a fight. A rare very hard single punch, or a series of lesser blows over a short period of time, can both lead to a knockout. But a series of light blows over a longer time may have no effect, Zhu said.
Researchers already have other examples of how mechanical force can affect the operation of cellular systems. For instance, mechanical stress created by blood flow acting on the endothelial cells that line blood vessel walls plays a role in the disease atherosclerosis. Force is also necessary for proper bone growth and healing. That mechanical forces would also play a role in the immune system therefore isn’t surprising, Zhu said.
“We now have a broader recognition that the physical environment and mechanical environment regulate many of the biological phenomena in the body,” he said. “When you exert a force on the TCR bonds, some of them dissociate faster, while others come off more slowly. This has an effect on the response of the T-cell receptor.”
In their experiments, Zhu and collaborators Baoyu Liu, Wei Chen and Brian Evavold used a biomembrane force probe to measure the strength and longevity of bonds between T cells and antigens. The probe consists, in part, of a red blood cell aspirated to a micropipette. Attached to the red blood cell is a bead on which researchers place the antigen under study. Using a delicate mechanism that precisely controls motion, the bead is then moved into contact with a T-cell receptor, allowing binding to take place.
To test the strength of bond formed between an antigen and the TCR, the researchers apply piconewton forces to separate the bead holding the antigen from the TCR. The red blood cell acts as a spring, stretching and allowing a measurement of the forces that must be applied to separate the TCR and antigen. The technique, which requires motion control at the nanometer scale, allows measurement of binding between the antigen and a single TCR.
To assess the impact of the binding on intracellular signaling, the researchers inject a dye into the cells that fluoresces when exposed to the calcium signaling ions. Detecting the fluorescence allowed the researchers to know when the mechanical force triggered T-cell signaling.
“We can directly look at kinetics and signaling at the same time,” explained Liu, a research scientist in the Coulter Department and co-first author of the paper. “We can observe the signaling directly induced by TCR interactions.”
As a next step, Zhu’s team would like to explore the effects of force on development of T-cells using the new experimental techniques. Evidence suggests that the forces to which the cells are exposed while they are in a juvenile stage may affect the fates of their development.
This research was supported by the National Institute of Allergy and Infectious Diseases (NIAID) and the National Institute of General Medical Sciences (NIGMS), both part of National Institutes of Health, through awards AI38282 and GM096187. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
CITATION: Baoyu Liu, Wei Chen, Brian D. Evavold and Cheng Zhu, “Accumulation of Dynamic Catch Bonds between TCR and Agonist Peptide-MHC Triggers T-Cell Signaling, “ (Cell 2014).
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]]>In a proof-of-concept study, scientists selected a region for analysis on round or irregularly-shaped objects using a 3-D camera on a robotic arm, which mapped the 3-dimentional coordinates of the sample’s surface. The scientists programmed the robotic arm to poke the sample with an acupuncture needle. The needle collected a small amount of material that the robot deposited in a nearby mass spectrometer, which is a powerful tool for determining a substance’s chemical composition.
“You see the object on a monitor and then you can point and click and take a sample from a particular spot and the robot will go there,” said Facundo Fernandez, a professor in the School of Chemistry and Biochemistry, whose lab led the study. “We’re using an acupuncture needle that will touch very carefully on the surface of the object and then the robot will turn around and put the material inside of a high resolution mass spectrometer.”
The research was published online February 28 in the journal Analyst, a publication of the Royal Society of Chemistry. The research will be featured on the cover of an upcoming print issue. The work was supported by a National Science Foundation (NSF) Major Research Instrumentation Program (MRI) grant and by the National Science Foundation (NSF) and NASA Astrobiology Program, under the NSF Center for Chemical Evolution.
Mass spectrometry is a powerful tool for analyzing surface chemistry or for identifying biological samples. It’s widely used in research labs across many disciplines, but samples for analysis typically have to be cleaned, carefully prepared, and in the case of rocks, cut into thin, flat samples. The new robotic system is the first report of a 3-D mass spectrometry native surface imaging experiment.
“Other people have used an acupuncture needle to poke a sample and then put that in mass spec, but nobody has tried to do a systematic, three-dimensional surface experiment,” Fernandez said. “We are trying to push the limits.”
To show that the system was capable of probing a three-dimensional object, the researchers imprinted ink patterns on the surfaces of polystyrene spheres. The team then used the robotic arm to model the surfaces, probe specific regions, and see if samples collected were sufficient for mass spectrometry analysis. The researchers were able to detect inks of different colors and create a 3-D image of the object with sufficient sensitivity for their proof-of-principle setup, Fernandez said.
The research was the result of collaboration between Fernandez’s group, which specializes in mass spectrometry, and Henrik Christensen’s robotics group in the College of Computing. Christensen is the KUKA Chair of Robotics and a Distinguished Professor of Computing. He is also the executive director of the Institute for Robotics and Intelligent Machines (IRIM) at Georgia Tech.
“The initial findings of this study mark a significant step toward using robots for three-dimensional surface experiments on geological material,” Christensen said. “We are using the repeatability and accuracy of robots to achieve new capabilities that have numerous applications in biomedical areas such as dermatology.”
“It doesn’t happen very often that a group in mass spectrometry will have a very talented robotics group next to them,” Fernandez said. “If we tried to learn the robotics on our own it could take us a decade, but for them it’s something that’s not that difficult.”
Christensen’s team loaned a Kuka KR5 sixx R650 robot to Fernandez’s lab for the study. Afterwards, Fernandez’s lab purchased their own robot from Universal Robots. They have also upgraded to a new mass spectrometer capable of resolution nearly eight times higher than the one used in the study. They will soon begin replicating early Earth chemistry on rocks and analyzing the reaction products with their robotic sampling system.
“We really want to look at rocks,” Fernandez said. “We want to do reactions on rocks and granites and meteorites and then see what can be produced on the surface.”
The technology could also be applied to other research fields, Fernandez said. For example, the robot-mass spec combo might be useful to dermatologists who often probe lesions on the skin, which have distinct molecular signatures depending on if the lesion is a tumor or normal skin tissue.
This research is supported by the American Recovery and Reinvestment Act (ARRA) under the National Science Foundation (NSF) Major Research Instrumentation Program (MRI) (Grant number 0923179), and by the NSF and NASA Astrobiology Program under the NSF Center for Chemical Evolution (CHE-1004579). Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Rachel V. Bennett, et al., “Robotic Plasma Probe Ionization Mass Spectrometry (RoPPI-MS) of Non-Planar Surfaces.” (Analyst, February 2014) http://dx.doi.org/10.1039/c4an00277f
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]]>By inserting enzymes from trees into the bacterium, first author and Georgia Tech graduate student Stephen Sarria, working under the guidance of assistant professor Pamela Peralta-Yahya, boosted pinene production six-fold over earlier bioengineering efforts. Though a more dramatic improvement will be needed before pinene dimers can compete with petroleum-based JP-10, the scientists believe they have identified the major obstacles that must be overcome to reach that goal.
Funded by Georgia Tech startup funds awarded to Peralta-Yahya’s lab and by the U.S. Department of Energy’s Office of Science, the research was reported February 27, 2014, in the journal ACS Synthetic Biology.
“We have made a sustainable precursor to a tactical fuel with a high energy density,” said Peralta-Yahya, an assistant professor in the School of Chemistry and Biochemistry and the School of Chemical and Biomolecular Engineering at Georgia Tech. “We are concentrating on making a ‘drop-in’ fuel that looks just like what is being produced from petroleum and can fit into existing distribution systems.”
Fuels with high energy densities are important in applications where minimizing fuel weight is important. The gasoline used to power automobiles and the diesel used mainly in trucks both contain less energy per liter than the JP-10. The molecular arrangement of JP-10, which includes multiple strained rings of carbon atoms, accounts for its higher energy density.
The amount of JP-10 that can be extracted from each barrel of oil is limited, and sources of potentially comparable compounds such as trees can’t provide much help. The limited supply drives the price of JP-10 to around $25 per gallon. That price point gives researchers working on a biofuel alternative a real advantage over scientists working on replacing gasoline and diesel.
“If you are trying to make an alternative to gasoline, you are competing against $3 per gallon,” Peralta-Yahya noted. “That requires a long optimization process. Our process will be competitive with $25 per gallon in a much shorter time.”
While much research has gone into producing ethanol and bio-diesel fuels, comparatively little work has been done on replacements for the high-energy JP-10.
Peralta-Yahya and collaborators set out to improve on previous efforts by studying alternative enzymes that could be inserted into the E. coli bacterium. They settled on two classes of enzymes – three pinene synthases (PS) and three geranyl diphosphate synthases (GPPS) – and experimented to see which combinations produced the best results.
Their results were much better than earlier efforts, but the researchers were puzzled because for a different hydrocarbon, similar enzymes produced more fuel per liter. So they tried an additional step to improve their efficiency. They placed the two enzymes adjacent to one another in the E. coli cells, ensuring that molecules produced by one enzyme would immediately contact the other. That boosted their production to 32 milligrams per liter – much better than earlier efforts, but still not competitive with petroleum-based JP-10.
Peralta-Yahya believes the problem now lies with built-in process inhibitions that will be more challenging to address.
“We found that the enzyme was being inhibited by the substrate, and that the inhibition was concentration-dependent,” she said. “Now we need either an enzyme that is not inhibited at high substrate concentrations, or we need a pathway that is able to maintain low substrate concentrations throughout the run. Both of these are difficult, but not insurmountable, problems.”
To be competitive, the researchers will have to boost their production of pinene 26-fold. Peralta-Yahya says that’s within the range of possibilities for bioengineering the E. coli.
“Even though we are still in the milligrams per liter level, because the product we are trying to make is so much more expensive than diesel or gasoline means that we are relatively closer,” she said.
Theoretically, it may be possible to produce pinene at a cost lower than that of petroleum-based sources. If that can be done – and if the resulting bio-fuel operates well in these applications – that could open the door for lighter and more powerful engines fueled by increased supplies of high-energy fuels. Pinene dimers, which result from the dimerization of pinene, have already been shown to have an energy density similar to that of JP-10.
Co-authors from the Joint BioEnergy Institute included Betty Wong, Hector Garcia Martin and Professor Jay D. Keasling, co-corresponding author of the paper.
CITATION: Stephen Sarria, et al., “Microbial Synthesis of Pinene,” (ACS Synthetic Biology, 2014). (http://dx.doi.org/10.1021/sb4001382).
This work was started at the DOE Joint BioEnergy Institute (JBEI) and finished at the Georgia Institute of Technology. The work at JBEI was funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research through contract DE-AC02-05CH11231 between Lawrence Berkeley National Laboratory and the U.S. Department of Energy. The work at the Georgia Institute of Technology was funded by startup funds awarded to the Peralta-Yahya laboratory. Any opinions expressed are those of the authors and do not necessarily represent the official views of the DOE.
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]]>The new thermal interface material could be used to draw heat away from electronic devices in servers, automobiles, high-brightness LEDs and certain mobile devices. The material is fabricated on heat sinks and heat spreaders and adheres well to devices, potentially avoiding the reliability challenges caused by differential expansion in other thermally-conducting materials.
“Thermal management schemes can get more complicated as devices get smaller,” said Baratunde Cola, an assistant professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. “A material like this, which could also offer higher reliability, could be attractive for addressing thermal management issues. This material could ultimately allow us to design electronic systems in different ways.”
The research, which was supported by the National Science Foundation, was reported March 30 in the advance online publication of the journal Nature Nanotechnology. The project involved researchers from the Georgia Institute of Technology, University of Texas at Austin, and the Raytheon Company. Virendra Singh, a research scientist in the Woodruff School, and Thomas Bougher, a Ph.D. student in the Woodruff School, are the paper’s co-first authors.
Amorphous polymer materials are poor thermal conductors because their disordered state limits the transfer of heat-conducting phonons. That transfer can be improved by creating aligned crystalline structures in the polymers, but those structures – formed through a fiber drawing processes – can leave the material brittle and easily fractured as devices expand and contract during heating and cooling cycles.
The new interface material is produced from a conjugated polymer, polythiophene, in which aligned polymer chains in nanofibers facilitate the transfer of phonons – but without the brittleness associated with crystalline structures, Cola explained. Formation of the nanofibers produces an amorphous material with thermal conductivity of up to 4.4 watts per meter Kelvin at room temperature.
The material has been tested up to 200 degrees Celsius, a temperature that could make it useful for applications in vehicles. Solder materials have been used for thermal interfaces between chips and heat sinks, but may not be reliable when operated close to their reflow temperatures.
“Polymers aren’t typically thought of for these applications because they normally degrade at such a low temperature,” Cola explained. “But these conjugated polymers are already used in solar cells and electronic devices, and can also work as thermal materials. We are taking advantage of the fact that they have a higher thermal stability because the bonding is stronger than in typical polymers.”
The structures are grown in a multi-step process that begins with an alumina template containing tiny pores covered by an electrolyte containing monomer precursors. When an electrical potential is applied to the template, electrodes at the base of each pore attract the monomers and begin forming hollow nanofibers. The amount of current applied and the growth time control the length of the fibers and the thickness of their walls, while the pore size controls the diameter. Fiber diameters range from 18 to 300 nanometers, depending on the pore template.
After formation of the monomer chains, the nanofibers are cross-linked with an electropolymerization process, and the template removed. The resulting structure can be attached to electronic devices through the application of a liquid such as water or a solvent, which spreads the fibers and creates adhesion through capillary action and van der Waals forces.
“With the electrochemical polymerization processing approach that we took, we were able to align the chains of the polymer, and the template appears to prevent the chains from folding into crystals so the material remained amorphous,” Cola explained. “Even though our material is amorphous from a crystalline standpoint, the polymer chains are highly aligned – about 40 percent in some of our samples.”
Though the technique still requires further development and is not fully understood theoretically, Cola believes it could be scaled up for manufacturing and commercialization. The new material could allow reliable thermal interfaces as thin as three microns – compared to as much as 50 to 75 microns with conventional materials.
“There are some challenges with our solution, but the process is inherently scalable in a fashion similar to electroplating,” he said. “This material is well known for its other applications, but ours is a different use.”
Engineers have been searching for an improved thermal interface material that could help remove heat from electronic devices. The problem of removing heat has worsened as devices have gotten both smaller and more powerful.
Rather than pursue materials because of their high thermal conductivity, Cola and his collaborators investigated materials that could provide higher levels of contact in the interface. That’s because in some of the best thermal interface materials, less than one percent of the material was actually making contact.
“I stopped thinking so much about the thermal conductivity of the materials and started thinking about what kinds of materials make really good contact in an interface,” Cola said. He decided to pursue polythiophene materials after reading a paper describing a “gecko foot” application in which the material provided an estimated 80 percent contact.
Samples of the material have been tested to 200 degrees Celsius through 80 thermal cycles without any detectable difference in performance. While further work will be necessary to understand the mechanism, Cola believes the robustness results from adhesion of the polymer rather than a bonding.
“We can have contact without a permanent bond being formed,” he said. “It’s not permanent, so it has a built-in stress accommodation. It slides along and lets the stress from thermal cycling relax out.”
In addition to those already mentioned, co-authors of the paper included Professor Kenneth Sandhage, Research Scientist Ye Cai, Assistant Professor Asegun Henry and graduate assistant Wei Lv of Georgia Tech; Prof. Li Shi, Annie Weathers, Kedong Bi, Micheal T. Pettes and Sally McMenamin in the Department of Mechanical Engineering at the University of Texas at Austin; and Daniel P. Resler, Todd Gattuso and David Altman of the Raytheon Company.
A patent application has been filed on the material. Cola has formed a startup company, Carbice Nanotechnologies, to commercialize thermal interface technologies. It is a member of Georgia Tech’s VentureLab program.
This research was supported by the National Science Foundation (NSF) through award CBET-113071, a seed grant from the Georgia Tech Center for Organic Photonics and Electronics and an NSF-IGERT graduate fellowship. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the NSF.
CITATION: Virendra Singh, et al., “High thermal conductivity of chain-oriented amorphous polythiophene,” (Nature Nanotechnology, 2014). http://www.dx.doi.org/10.1038/nnano.2014.44
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]]>The study is the first to examine how aspirin and another heart attack prevention drug respond to a variety of mechanical blood flow forces in healthy and diseased arteries. Patients’ blood was tested in a patent-pending microfluidic device with narrow passageways to simulate the coronary arteries. The data are consistent with clinical findings showing that physiology has a major influence on the effectiveness of drugs used for heart attack prevention.
The researchers believe that a benchtop diagnostic device like the one used in this study could save lives by preventing heart attacks and help lower healthcare costs by giving physicians better guidance on how drugs may affect individual patients.
“Doctors have many drug options and it is difficult for them to determine how well each of those options is going to work for a patient,” said Melissa Li, who was a graduate student at the Georgia Institute of Technology at the time of the study. “This study is the first time that a prototype benchtop diagnostic device has tried to address this problem using varying shear rates and patient dosing and tried to make it more personalized.”
The study was sponsored by the American Heart Association, a Wallace H. Coulter Foundation Translational Grant and by a fellowship from the Technological Innovation: Generating Economic Results (TI:GER) program at Georgia Tech. The study was published in a recent edition of the journal PLOS ONE.
About 10 percent of the U.S. population takes drugs every day because they are at risk of a heart attack. When a patient comes to a hospital with heart disease, doctors have multiple treatment options, all with different routes of action, time scales and prices.
“For a patient being prescribed anti-thrombotic drugs who is at risk for a heart attack, we can draw a small amount of their blood and quickly push a little bit through this device, and based on that information, tell them to take a certain amount of a certain drug. That’s where we’re going with this project,” said Craig Forest, an assistant professor of bioengineering in the George W. Woodruff School of Mechanical Engineering at Georgia Tech. Forest’s lab led the study in collaboration with David Ku, a medical doctor and mechanical engineering professor at Georgia Tech. Ku is the Lawrence P. Huang Chair Professor of Engineering Entrepreneurship and a Regents' Professor of Mechanical Engineering.
For the current study, researchers used the diagnostic device to examine two treatments for potential heart attacks: aspirin and a class of drugs called GPIIb/IIIa-inhibitors. GPIIb/IIIa-inhibitors are generally given to patients with a high risk for a heart attack, and these drugs can be expensive. The study found that the two drugs have very different effects on blood clotting.
When arteries are constricted, such as in patients with atherosclerosis, blood must squeeze through narrow passages. That pressurized flow induces a mechanical force called shear. Under high shear rates in arteries— blood flowing through a narrow opening — blood is more likely to clot. When blood is forced to squeeze through a small opening, platelets hook together, forming a clot.
To show how these drugs affect clotting at high and normal shear rates, blood samples were drawn from patients over several days. The scientists added the two drugs at different doses to those blood samples and ran them through a microfluidic device. The microfluidic device has four channels that mimic the coronary arteries, allowing researchers to study clotting under a variety of conditions.
“What we found is that with lower shear rates, such as found in normal arteries, aspirin was fairly effective at stopping platelets from clumping up with each other,” said Li, who is now a postdoctoral fellow at the University of Washington. “At higher shear rates, aspirin was not as effective at preventing these clots.”
The researchers found that under high shear rates, clots still formed in the presence of aspirin, but that the clots became unstable and broke off the simulated artery walls.
Li said that their evidence suggests that aspirin should be fairly effective for most people at preventing heart attacks, but not as effective at preventing heart attacks in patients with atherosclerosis. This study can help identify which individuals can be helped, and which cannot.
The current study would need to be replicated in a large, controlled study before this device can be moved to the clinic or hospital.
“This finding is something that’s been echoed in the literature by physicians who would find that a number of patients who would take aspirin were not receiving any clinical benefit,” Li said. “This is an explanation mechanically of why that might occur.”
That phenomenon has been called aspirin resistance, which is a catchall term for when patients don’t respond to aspirin for unknown reasons.
“What we showed is a good explanation for the conditions under which aspirin resistance occurs and one that matches up with what other people have found,” Li said.
GPIIb/IIIa-inhibitors were effective at preventing blood clots across all shear rates tested, the study found, suggesting that these drugs would be effective for people whether they had atherosclerosis. Clinical evidence also supports this finding, Li said.
The researchers used a statistical method known as the Cox-Hazard analysis, performed by bioengineering graduate student Nathan Hotaling. The analysis is commonly used by doctors to determine if drugs are safe for a patient. Using this analysis in a prototype benchtop diagnostic device is a unique approach and showed that, statistically, the research findings were significant.
“These microfluidic devices are so cheap and require so little blood that it could become possible for someone to use this in a disposable, rapid way,” said Forest.
This research is supported by the American Heart Association (10GRNT4430029), a Wallace H. Coulter Foundation Translational Grant and by a fellowship from the Technological Innovation Generating Economic Results (TI:GER) program at Georgia Tech. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Melissa Li, et al., “Microfluidic Thrombosis under Multiple Shear Rates and Antiplatelet Therapy Doses,” (PLOS ONE, January 2014). (http://dx.doi.org/10.1371/journal.pone.0082493).
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]]>A new study found that neural circuits in the brain rapidly multitask between detecting and discriminating sensory input, such as headlights in the distance. That’s different from how electronic circuits work, where one circuit performs a very specific task. The brain, the study found, is wired in way that allows a single pathway to perform multiple tasks.
“We showed that circuits in the brain change or adapt from situations when you need to detect something versus when you need to discriminate fine details,” said Garrett Stanley, an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, whose lab performed the research. “One of the things the brain is good at is doing multiple things. Engineers have trouble with that.”
The research findings were published online in the journal NEURON on March 5. The research was funded by the National Institutes of Health (NIH) and the National Science Foundation (NSF).
“Every day we are bombarded with sensations and the brain automatically chooses which ones to detect. This study may help scientists answer fundamental questions about how neurological disorders may disrupt the brain circuits that make those choices,” said Jim Gnadt, Ph.D., program director at the National Institute of Neurological Disorders and Stroke, part of NIH. “Insights into sensory perception may help design new therapies, including prosthetic devices for amputees that recreate human touch.”
The distance at which a person can discern two headlights from a single light is controlled by the acuity of the body’s sensory pathway. For decades neuroscientists have assumed that the level of one’s acuity is controlled by the distance between areas in the brain that are triggered by the sensory input. If these two areas of the brain closely overlap, then two sensory inputs — two headlights in the distance — will appear as one, the thinking went. The new study, for the first time, used animal models and optical imaging to directly assess how acuity is controlled in the brain, and how acuity can adapt to the task at hand. One neuronal circuit can do different things and do them in a robust way, the study found.
“The general problem that is not well understood is how information about the outside world makes its way into our brain, into these patterns of electrical activity that ultimately let us perceive the outside world,” Stanley said. “This paper squarely goes after that link between what the brain is doing, how it’s activated and what that means for perception.”
Sensory information is encoded in the brain, much like gene sequences in DNA code for some physical representation. The brain has corresponding codes for when the visual pathway detects an object, like a coffee cup. There’s a representation in the brain to transform that input into sensation.
Researchers had yet to adequately quantify the link between discerning whether an object exists and discriminating finer details about what that object is, Stanley said.
“Surprisingly, we don’t understand neural coding problems very well, either in normal physiology or in disease states,” Stanley said. “I think it’s great to be an engineer that works on this because engineers tend to love and think about very complicated systems.”
To learn about the details of the brain’s acuity, the researchers studied an animal with a high level of acuity — the rat. Rats are nocturnal animals that use their whiskers to sense the outside world. Their whiskers are arranged in rows, and chunks of brain tissue correspond to those individual whiskers. That’s similar to how a human’s body surface is mapped onto the brain surface. When a rat’s whisker touches something, a specific part of the brain becomes activated. When a person’s finger touches something, a specific part of the brain becomes activated.
“When we image the brain, we can move a whisker on the side of the face and on the opposite side of the brain there’s a little hotspot that you can image in real time,” Stanley said.
The researchers deflected rats’ whiskers and then used optical imaging technology to observe the areas of the brain that were activated and measured the overlap between those areas. Rats were also trained to perform a specific task depending on which whisker was deflected.
The researchers found that pathways in the brain have the ability to switch between doing different kinds of tasks, such as detecting a sensory input and deciding what to do with that information.
“Same circuit, same cells, but doing something different in two different contexts,” Stanley said.
When engineers want a circuit to do something, they build a circuit specific for that task. When they want a circuit to do something else, they build a different circuit. But in the brain, a pathway adaptively changes between being good at detecting something to being good at discriminating something, the study showed.
“As an engineer, I can’t design a circuit that would do that,” Stanley said. “This is where the brain jumps out and says, ‘I’m better than you are at this.’”
Learning more about how circuits in the brain multitask could lead to a better understanding of disease, therapeutic applications or to potentially improving how the brain functions. Stanley said that down the road engineers might be able to experimentally manipulate brain circuits to perform a desired task.
“Can we make individuals better at doing something? Can we have them detect things more rapidly or discriminate between things with better acuity?” Stanley said. “Using modern techniques, we believe that we can actually influence the circuit and have it selectively grab one kind of information from the outside world versus another.”
This research is supported by the National Institutes of Health (NIH) under award number R01NS48285, and by the National Science Foundation (NSF) Collaborative Research in Computational Neuroscience (CRCNS) program under award number IOS-1131948. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Douglas Ollerenshaw, et al., “The adaptive trade-off between detection and discrimination in cortical representations and behavior,” (NEURON, March 2014). (http://dx.doi.org/10.1016/j.neuron.2014.01.025).
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]]>The app pulls GPS data from buses and trains and provides real-time arrival and departure data on users’ smartphones, computers or on large video displays in stores or public areas. The app was integrated into Atlanta’s transit network by Georgia Tech researchers last year, and the app’s developers plan to add bus data for Georgia Regional Transportation Authority (GRTA) Xpress, Cobb Community Transit (CCT), Gwinnett County Transit, the Atlantic Station shuttle, other local university systems, and other systems equipped with GPS tracking. (Download and try the app by clicking here)
“This app helps people who want the information before they get to the train station or bus stop,” said Kari Watkins, an assistant professor in the School of Civil and Environmental Engineering at Georgia Tech. “For bus and shuttle stops where there is no sign for next arrivals this app is the rider’s only source of information.”
OneBusAway is free to download and has information on transit systems in Atlanta, Seattle and Tampa. The app automatically recognizes which city the user is in, and captures data from the local transit source. The coding for the transit-tracking app was used to develop New York City’s MTA Bus Time.
The app gathers real-time location data by tapping GPS units already installed on buses and trains. Recently, MARTA made their GPS data publicly available so that software developers might use it to build apps and other tools to improve the rider experience. Riders can search OneBusAway for nearby train and bus stops and receive up-to-the-minute arrival and departure information.
MARTA also has a real-time transit-tracking app that provides information exclusively for its bus and train network.
“One of our priorities is improving the overall customer experience through the use of technology,” said Keith T. Parker, MARTA’s CEO. “That’s why we launched the On-the-Go mobile app providing real-time train and bus arrivals. We’re also excited to work with OneBusAway, and the metro Atlanta tech community, in developing solutions that will help retain and attract transit riders.”
OneBusAway’s ability to combine data on multiple transit agencies in the Atlanta region might be one way to attract riders, by helping them transfer more easily between transit systems.
“The goal is to make OneBusAway multiagency, multiregional and multimodal,” said Watkins, who co-founded the app while at the University of Washington in Seattle and is known on Twitter as @transitmom.
The Atlanta version of the app is run by Watkins’ research group, the Urban Transportation Information Lab. It has been developed by students Tushar Humbe, from the School of Computer Science, and Landon Reed, from the School of Civil and Environmental Engineering.
The program is funded by Georgia Tech’s Institute for People and Technology (IPaT), Georgia Tech’s Graphics, Visualization, and Usability (GVU) Center, the National Center for Transportation Systems Productivity and Management and a U.S. Department of Transportation Eisenhower Fellowship.
The idea behind the app is to take a lot of the guesswork out of riding public transportation. When riders are still at their desks, at home or in a coffee shop, they can open the app on their smartphone or computer, search for nearby transit options, and know exactly how many minutes they have until the next bus or train arrives.
Watkins and Candace Brakewood, a PhD student with Watkins’ group, are launching a new study in April that seeks to quantify how real-time transit information affects ridership through studies in Atlanta and New York City.
Prior studies from Watkins and colleagues of the OneBusAway app in Seattle and Tampa found that the app’s users have a more favorable view of transit, feel safer on transit, spend less time waiting on buses and trains and report riding transit more.
OneBusAway utilizes open-source software, so enterprising transit riders can suggest tweaks to the app or develop their own transit-arrival signs. On the web, OneBusAway features a mode that is compatible with large displays, so that businesses near transit can display real-time information for patrons wishing to ride a bus or train.
Someday, Watkins envisions, transit riders will have an app that knows their route to work, what time they want to arrive, and sends alerts if a bus or train is going to be early or late.
“It gives back some of the power you give away as a transit rider,” Watkins said.
Watkins is a Georgia Tech alumna (CE 97) and was recently named to Mass Transit Magazine’s 40 Under 40 list. Her Cycle Atlanta and OneBusAway apps have been making the rounds in local and national media for the ways they could change how people commute. She’s also been an expert source for transportation stories by NPR and The Atlantic Cities.
“We’re all figuring out how we can optimize what we have and make better use of the space that exists,” Watkins said. “Even those who aren’t environmentally minded recognize the congestion and space issues and are tired of it. We have to make all our modes function better, which includes providing better information.”
Download the free apps for Android, iPhone and Windows Phone or visit atlanta.onebusaway.org for more information.
This research is supported by the National Center for Transportation Systems Productivity and Management, a U.S. Department of Transportation’s (DOT) Research and Innovative Technology Administration (RITA) University Transportation Center. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.
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]]>Arrays of the tweezers could be combined to study multiple molecules and cells simultaneously, providing a high-throughput capability for assessing the effects of mechanical forces on a broad scale. Details of the devices, which were developed by researchers at the Georgia Institute of Technology and Emory University in Atlanta, were published February 19, 2014, in the journal Technology.
“Our lab has been very interested in mechanical-chemical switches in the extracellular matrix, but we currently have a difficult time interrogating these mechanisms and discovering how they work in vivo,” said Thomas Barker, an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “This device could help biologists and biomedical engineers answer questions that cannot be answered right now.”
For example, a cell that’s binding the extracellular matrix may bind with one receptor while the matrix is being stretched, and a different receptor when it’s not under stress. Those binding differences could drive changes in cell phenotype and affect processes such as cell differentiation. But they are now difficult to study.
“Having a device like this will allow us to interrogate what the specific binding sites are and what the specific binding triggers are,” Barker explained. “Right now, we know very little about this area when it comes to protein biochemistry.”
Scientists have been able to study how single cells or proteins are affected by mechanical forces, but their activity can vary considerably from cell-to-cell and among molecules. The new tweezers, which are built using nanolithography, can facilitate studying thousands or more cells and proteins in aggregate. The researchers are currently testing prototype 15 by 15 arrays which they believe could be scaled up.
“For me, it’s not sufficient to pull and hold onto a single protein,” said Barker. “I have to pull and hold onto tens of thousands of proteins to really use the technologies we have to develop molecular probes.”
At the center of the tweezers are 2.8- micron polystyrene microbeads that contain superparamagnetic nanoparticles. The tiny beads are engineered to adhere to a sample being studied. That sample is attached to a bead on one side, and to a magnetic pad on the other. The magnet draws the bead toward it, while an electrophoretic force created by current flowing through a gold wiring pattern pushes the bead away.
“The device simultaneously pushes and pulls on the same particle,” Barker explained. “This allows us to hold the sample at a very specific position above the magnet.”
Because the forces can be varied, the tweezers can be used to study structures of widely different size scales, from protein molecules to cells – a size difference of approximately a thousand times, noted Wilbur Lam, an assistant professor in the Coulter Department. Absolute forces in the nano-Newton range applied by the two sources overcome the much smaller effects of Brownian motion and thermal energy, allowing the tweezers to hold the cells or molecules without constant adjustment.
“We are basically leveraging microchip technology that has been developed by electrical and mechanical engineers,” Lam noted. “We are able to leverage these very tiny features that enable us to create a very sharp electrical field on one end against an opposing short magnetic field. Because there are two ways of controlling it, we have tight resolution and can get to many different scales.”
As a proof of principle for the system, the researchers demonstrated its ability to distinguish between antigen binding to loaded magnetic beads coated with different antibodies. When a sufficient upward force is applied, non-specific antibody coated beads are displaced from the antigen-coated device surface, while beads coated with the specific antibody are more strongly attracted to the surface and retained on it.
Barker and Lam began working together on the tweezers three years ago when they realized they had similar interests in studying the effects of mechanical action on different biological systems.
“We shouldn’t be surprised that biology can be dictated by physical parameters,” Lam explained. “Everything has to obey the laws of physics, and mechanics gets to the heart of that.”
Lam’s interest is at the cellular scale, specifically in blood cells.
“Blood cells also respond differently, biologically, when you squeeze them and when you stretch them,” he said. “For instance, we have learned that mechanics has a lot to do with atherosclerosis, but the systems we currently have for studying this mechanism can only look at single-cell events. If you can look at many cells at once, you get a much better statistical view of what’s happening.”
Barker’s interests, however, are at the molecular level.
“We are primarily interested in evolving antibodies that are capable of distinguishing different force-mediated conformations of proteins,” he explained. “We have a specific protein that we are interested in, but this technique could be applied to any proteins that are suspected to have these force-activated changes in their biochemical activity.”
While the tweezers meet the specific experimental needs of Lam and Barker, the researchers hope to find other applications. The tweezers were developed in collaboration with graduate student Lizhi Cao and post-doctoral fellow Zhengchun Peng.
“Because of the scale we are able to examine – both molecular and cellular – I think this will have a lot of applications both in protein molecular engineering and biotechnology,” Lam said. “This could be a useful way for people to screen relevant molecules because there currently aren’t good ways to do that.”
Beyond biological systems, the device could be used in materials development, microelectronics and even sensing.
“This ability to detect discrete binding and unbinding events between molecular species is of high interest right now,” Barker added. “Biosensor applications come out of this naturally.”
CITATION: Lizhi Cao, et al., “A combined magnetophoresis/dielectrophoresis based microbead array as a high-throughput biomolecular tweezers,” (Technology 2014). http://dx.doi.org/10.1142/S2339547814500058
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]]>Although these operating speeds were achieved at extremely cold temperatures, the research suggests that record speeds at room temperature aren't far off, said professor John D. Cressler, who led the research for Georgia Tech. Information about the research was published in February 2014, by IEEE Electron Device Letters.
"The transistor we tested was a conservative design, and the results indicate that there is significant potential to achieve similar speeds at room temperature – which would enable potentially world changing progress in high data rate wireless and wired communications, as well as signal processing, imaging, sensing and radar applications," said Cressler, who hold the Schlumberger Chair in electronics in the Georgia Tech School of Electrical and Computer Engineering. "Moreover, I believe that these results also indicate that the goal of breaking the so called ‘terahertz barrier’ – meaning, achieving terahertz speeds in a robust and manufacturable silicon-germanium transistor – is within reach."
Meanwhile, Cressler added, the tested transistor itself could be practical as is for certain cold-temperature applications. In particular, it could be used in its present form for demanding electronics applications in outer space, where temperatures can be extremely low.
IHP, a research center funded by the German government, designed and fabricated the device, a heterojunction bipolar transistor (HBT) made from a nanoscale SiGe alloy embedded within a silicon transistor. Cressler and his Georgia Tech team, including graduate students Partha S. Chakraborty, Adilson S. Cardoso and Brian R. Wier, performed the exacting work of analyzing, testing and evaluating the novel transistor.
“The record low temperature results show the potential for further increasing the transistor speed toward terahertz (THz) at room temperature. This could help enable applications of Si-based technologies in areas in which compound semiconductor technologies are dominant today. At IHP, B. Heinemann, H. Rücker, and A. Fox supported by the whole technology team working to develop the next THz transistor generation,” according to Bernd Tillack, who is leading the technology department at IHP in Frankfurt (Oder), Germany.
Silicon, a material used in the manufacture of most modern microchips, is not competitive with other materials when it comes to the extremely high performance levels needed for certain types of emerging wireless and wired communications, signal processing, radar and other applications. Certain highly specialized and costly materials – such as indium phosphide, gallium arsenide and gallium nitride – presently dominate these highly demanding application areas.
But silicon-germanium changes this situation. In SiGe technology, small amounts of germanium are introduced into silicon wafers at the atomic scale during the standard manufacturing process, boosting performance substantially.
The result is cutting-edge silicon germanium devices such as the IHP Microelectronics 800 GHz transistor. Such designs combine SiGe's extremely high performance with silicon's traditional advantages – low cost, high yield, smaller size and high levels of integration and manufacturability – making silicon with added germanium highly competitive with the other materials.
Cressler and his team demonstrated the 800 GHz transistor speed at 4.3 Kelvins (452 degrees below zero, Fahrenheit). This transistor has a breakdown voltage of 1.7 V, a value which is adequate for most intended applications.
The 800 GHz transistor was manufactured using IHP’s 130-nanometer BiCMOS process, which has a cost advantage compared with today’s highly-scaled CMOS technologies. This 130 nm SiGe BiCMOS process is offered by IHP in a multi-project wafer foundry service.
The Georgia Tech team used liquid helium to achieve the extremely low cryogenic temperatures of 4.3 Kelvins in achieving the observed 798 GHz speeds. "When we tested the IHP 800 GHz transistor at room temperature during our evaluation, it operated at 417 GHz," Cressler said. "At that speed, it's already faster than 98 percent of all the transistors available right now."
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]]>What’s more, the new version will enable Apple iOS and Google Android mobile devices to run the software. Previously, the software worked only on Windows-based desktop and laptop computers. The Chemical Companion Decision Support System can be downloaded at (www.chemicalcompanion.org).
Although Chemical Companion originally targeted first responders in fire and rescue departments, today forensic teams and bomb squads also use it. Funded by the U.S. federal government’s Technical Support Working Group, U.S. Marine Corps Systems Command and Australia’s Department of the Prime Minister and Cabinet (now managed by the country’s Defence Science and Technology Organisation), the software is free to the military, law enforcement and fire departments. More than 1,200 active accounts are registered at ChemicalCompanion.org, with users in the United States, Australia, Canada, the United Kingdom, the Netherlands and Israel.
Whether the hazmat scene is due to a gas explosion, chemical spill, terrorist incident or bomb threat, the Chemical Companion helps mitigate risk. For example, a bomb squad can use it to determine potential scene blast, fragmentation and personnel standoff distances. It helps first responders decide how to decontaminate the scene and provide medical aid to victims. It also helps them determine what kind of protective equipment they need to wear and how long they can stay in a hot zone.
From E-reader to Integrated Toolkit
“When we first introduced the Chemical Companion, it functioned as an information portal with basic e-reader functionality that enabled first responders to access information without lugging a dozen or more books around with them,” said Gisele Bennett, director of the Georgia Tech Research Institute’s (GTRI) Electro-Optical Systems Lab and Chemical Companion’s principal investigator.
By entering details about a substance’s physical appearance or victims’ medical symptoms, the software allowed users to identify unknown chemicals at a hazmat scene and obtain information about their effects. “Today, however, Chemical Companion is more than just an information resource,” she said. “It has become a sophisticated decision-support system.”
Indeed, in the last two years, GTRI researchers have been developing a series of unique tools to enhance the Chemical Companion’s capabilities. These include, for example:
The respiratory protection tool – Released in August 2012, the respiratory protection tool takes users through a series of questions about environmental conditions and hazardous materials that may be present at a hazmat scene. The final screen delivers a recommendation on what type of respiratory protection is required. Respiratory protection comes in many forms, ranging from a half-face mask to a self-contained breathing apparatus (SCBA).
“Selection of the right equipment for a given environment can be confusing, so most first responders default to an SCBA which is heavy and restrictive,” explained Heyward Adams, a GTRI research scientist who serves as technical lead on the project. “The Chemical Companion’s respiratory protection tool allows users to determine the appropriate equipment to wear – providing full protection from the airborne threats with the minimum amount of equipment.”
The detection tool – First responders carry a variety of detector devices to help determine what chemical, biological and radiological threats may be present at a hazmat scene. The Chemical Companion’s detection tool augments the performance of these detectors by:
Taking measurements at a hazmat scene is no easy task, Adams said, noting that different detectors deliver readouts in different formats, such as a series of bars, parts per million or a color. “Unless you’re an expert in chemistry, these readouts are not easy to decipher,” he observed. “The Chemical Companion’s detection tool helps you know how to interpret the results and what to do with that information.”
Currently the Chemical Companion has more than 19 tools that have either launched or are being tested. Many of these tools complement each other, prompting researchers to investigate their integration. “The output of one tool could be the input for another,” Adams said. “Yet users might not realize that, so we’re creating links to make overlaps more intuitive.”
Users Drive New Features
Working closely with users has been critical to the Chemical Companion’s success.
In addition to rigorous testing and user trials before any new release, GTRI researchers host an annual workshop for users. This week-long event is instrumental in collecting feedback about the software’s structure and usability – whether it’s for developing a brand new tool or improving an existing feature.
“The workshops allow us to go through calculations of situations with different user groups,” said Bennett. “A forensics officer will approach a scene very differently than a first-responder or a firefighter.”
With that in mind, GTRI researchers have developed user preferences for three different audiences, along with country preferences that automatically populate national standards and units of measurement for the United States and Australia.
Another recent development sparked by the annual workshops is a tool for generating reports. Introduced in 2012, Chemical Companion’s Report Builder exports a PDF file that includes situational information, calculations and outputs performed by the software – even custom notes. “In some cases, this file becomes the actual after-action report that users turn in to their departments,” said Adams.
Beyond the Hazmat Scene
Because the Chemical Companion’s tools comprise multiple screens posing various questions and considerations, it has become an important training tool, points out Michael Logan, chief superintendent and scientific branch director of the Queensland Fire and Rescue Service in Brisbane, Australia. “It assists exercise writers with both the construction and accuracy of training scenarios,” explained Logan, who provides GTRI with research data and serves as a subject matter expert.
The tool also helps with emergency pre-planning, Logan said, explaining that the Chemical Companion can help estimate resources required or the effects of actions on an incident. “It enables users to challenge assumptions about incidents and the approaches that might be adopted to manage the emergencies.”
“The Chemical Companion’s combination of information and tools in one easy-to-use package makes a huge difference to users,” he continued. “It provides confidence to first responders about their safety and the communities they serve – as well as their actions. The software delivers consistent results no matter what the experience or expertise of the user during a very stressful time.”
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]]>To help coordinate a rapid response to pandemics, a professor at the Georgia Institute of Technology in Atlanta has designed software that combines biological data on the pandemic with demographic data of the at-risk population so that health officials can develop a game plan to limit the pandemic’s spread. The software also combs social media sites for real-time information on the pandemic and activities of the population.
Eva Lee, director of the Center for Operations Research in Medicine and HealthCare at the H. Milton Stewart School of Industrial and Systems Engineering at the Georgia Institute of Technology in Atlanta, talked about her emergency response software at the 2014 AAAS annual meeting in Chicago.
“We have developed a real-time system that will gather the demographics of the region that is being affected, and also pick up on-the-ground-data about who is available and doing what, and about movement of the affected population,” Lee said. “Our work is the first to take demographic information and real-time population behavior and interlace it with the biological information to come up with a decision that health officials can actually use.”
Lee chaired the panel titled “Emergency Response and Community Resilience via Engineering and Computational Advances.”
Lee shared her experience helping federal officials respond to the H1N1 flu in 2009, as well as her experience planning an emergency response to a potential anthrax outbreak. Lee was also involved in coordinating a response to the 2010 earthquake in Haiti, and the decontamination and health screening effort in Japan after the 2011 Fukushima radiological disaster.
Other speakers on the panel include Ronald Eguchi of ImageCat Inc. in Long Beach, Calif, who talked about inventory data capture tools to assess risk from natural disasters. Yasuaki Sakamoto, of Stevens Institute of Technology in Hoboken, N.J., spoke about improving social media for disaster response.
Emergency responders to a pandemic must quickly gather information on the biological agent to assess the characteristics of the pandemic and decide which treatment would be most effective. They also collect data on the risk factors of the individuals in the pandemic, such as the severity of patient’s sickness, and if children or pregnant women are infected.
“The big challenge in a pandemic is how do you use all of this information to determine the best strategy that will give you the minimum number of total infections and mortality rate,” Lee said.
Information from Lee’s systems approach allows health official to determine where to allocate medical resources and personnel in the best way so that operations will be most successful. Through the software developed in her lab at Georgia Tech, officials can determine, for example, how much vaccine to give at-risk populations and how much to give to the general populations to limit the spread of infection and mortality. Officials can also map where to set up medical sites to avoid traffic gridlock and worsening the pandemic as infected patients converge on treatment sites.
“We can do a real-time optimization to tell you exactly what are the sites that you should set up and who should be going where,” Lee said.
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]]>The study found little or no overlap in the most prominent genetic malfunction associated with each individual patient’s disease compared to malfunctions shared among the group of cancer patients as a whole.
“This paper argues for the importance of personalized medicine, where we treat each person by looking for the etiology of the disease in patients individually,” said John McDonald, a professor in the School of Biology at the Georgia Institute of Technology in Atlanta. “The findings have ramifications on how we might best optimize cancer treatments as we enter the era of targeted gene therapy.”
The research was published February 11 online in the journal PANCREAS and was funded by the Georgia Tech Foundation and the St. Joseph’s Mercy Foundation.
In the study, researchers collected cancer and normal tissue samples from four patients with pancreatic cancer and also analyzed data from eight other pancreatic cancer patients that had been previously reported in the scientific literature by a separate research group.
McDonald’s team compiled a list of the most aberrantly expressed genes in the cancer tissues isolated from these patients relative to adjacent normal pancreatic tissue.
The study found that collectively 287 genes displayed significant differences in expression in the cancers vs normal tissues. Twenty-two cellular pathways were enriched in cancer samples, with more than half related to the body’s immune response. The researchers ran statistical analyses to determine if the genes most significantly abnormally expressed on an individual patient basis were the same as those identified as most abnormally expressed across the entire group of patients.
The researchers found that the molecular profile of each individual cancer patient was unique in terms of the most significantly disrupted genes and pathways.
“If you’re dealing with a disease like cancer that can be arrived at by multiple pathways, it makes sense that you’re not going to find that each patient has taken the same path,” McDonald said.
Although the researchers found that some genes that were commonly disrupted in all or most of the patients examined, these genes were not among the most significantly disrupted in any individual patient.
“By and large, there appears to be a lot of individuality in terms of the molecular basis of pancreatic cancer,” said McDonald, who also serves as the director of the Integrated Cancer Research Center and as the chief scientific officer of the Ovarian Cancer Institute.
Though the study is small, it raises questions about the validity of pinpointing the most important gene or pathway underlying a disease by pooling data from multiple patients, McDonald said. He favors individual profiling as the preferred method for initiating treatment.
The cost of a molecular profiling analysis to transcribe the DNA sequences of exons — the parts of the genome that carry instructions for proteins — is about $2,000 (exons account for about two percent of a cell’s total DNA). That’s about half the cost of this analysis five years ago, McDonald said, and a $1,000 molecular profiling analysis might not be far off.
“As costs continue to come down, personalized molecular profiling will be carried out on more cancer patients,” McDonald said.
Yet cost isn’t the only limiting factor, McDonald said. Scientists and doctors have to shift their paradigm on how they use molecular profiling to treat cancer.
“Are you going to believe what you see for one patient or are you going to say, ‘I can’t interpret that data until I group it together with 100 other patients and find what’s in common among them,’” McDonald said. “For any given individual patient there may be mutant genes or aberrant expression patterns that are vitally important for that person’s cancer that aren’t present in other patients’ cancers.”
Future work in McDonald’s lab will see if this pattern of individuality is repeated in larger studies and in patients with different cancers. The group is currently working on a genomic profiling analysis of patients with ovarian and lung cancers.
“If there are multiple paths, then maybe individual patients are getting cancer from alternative routes,” McDonald said. “If that’s the case, we should do personalized profiling on each patient before we make judgments on the treatment for that patient.”
Loukia Lili, of Georgia Tech’s Integrated Cancer Research Center, School of Biology, and Parker H. Petit Institute of Bioengineering and Biosciences, was the study’s first author. Co-authors included Lilya Matyunina and DeEtte Walker of Georgia Tech, and George Daneker, MD, of the Cancer Treatment Centers of America SE Regional Facility in Newnan, Ga.
This research is supported by the Georgia Tech Foundation and the St. Joseph’s Mercy Foundation. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Loukia N. Lili, et al., “Evidence for the Importance of Personalized Molecular Profiling in Pancreatic Cancer,” (PANCREAS, February 2014). (http://dx.doi.org/10.1097/MPA.0000000000000020).
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]]>The research, which involved nearly 100 people recruited in the metropolitan Atlanta area, found that test subjects could successfully apply a prototype vaccine patch to themselves. That suggests the self-administration of vaccines with microneedle patches may one day be feasible, potentially reducing administration costs and relieving an annual burden on health care professionals.
The study also suggested that the use of vaccine patches might increase the rate at which the population is vaccinated against influenza. After comparing simulated vaccine administration using a patch and by conventional injection, the percentage of test subjects who said they’d be vaccinated grew from 46 percent to 65 percent.
“Our dream is that each year there would be flu vaccine patches available in stores or sent by mail for people to self-administer,” said Mark Prausnitz, a Regent’s professor in the School of Chemical and Biomolecular Engineering at the Georgia Institute of Technology. “People could take them home and apply them to the whole family. We want to get more people vaccinated, and we want to relieve health care professionals from the burden of giving these millions of vaccinations.”
The research on patient acceptance of vaccine patch immunization was published online February 11, 2014, by the journal Vaccine and will appear in a later edition of the print journal. In addition to Georgia Tech researchers, the project also included scientists from Emory University and the Centers for Disease Control and Prevention (CDC). Research into the use of microneedle patches for influenza vaccination has been supported by the National Institutes of Health (NIH).
The study is believed to be the first published report of a head-to-head comparison between microneedle patches and traditional intramuscular injection for the administration of vaccines in human subjects. The patches consisted of arrays of 50 microscopic needles about as tall as the thickness of a few hairs. When used for vaccination, the patches would be pressed painlessly onto a person’s forearm to carry vaccine into the outer layers of skin, where they would prompt an immune reaction from the body.
The 91 study subjects, who had no previous experience with microneedle patches, were given brief instructions on applying the patches to themselves. Each volunteer applied three patches, had a fourth patch applied by a member of the research team, and received an injection of saline with a conventional hypodermic needle. Neither the patches nor the hypodermic needle actually carried a vaccine, and the study did not assess the efficacy of using microneedle patches for vaccinations in humans.
The researchers evaluated how well the volunteers were able to self-administer the microneedle patches. After the subjects pressed the patches into their skin, the researchers applied a dye to highlight the tiny holes made by the microneedles. By photographing the administration sites and counting the number of holes, they were able to assess the accuracy of the application.
“We found that everyone was capable of administering a microneedle patch appropriately, though not everyone did on the first try,” Prausnitz said.
Some of the subjects used an applicator that made a clicking sound when sufficient force was applied to the patch. Use of that feedback device improved the ability of subjects to correctly apply patches and virtually eliminated administration mistakes.
During the study, the volunteers were asked if they planned to receive a flu vaccination in the next year and if their intent to be vaccinated would change if it could be done with the patch. The percentage saying they’d be vaccinated jumped from 46 to 65 percent when the patch was an option.
“If this holds for the population as a whole, that would have a tremendous impact on preventing disease and the cost associated with both influenza and the vaccination process,” said Paula Frew, an assistant professor in the Emory University School of Medicine and a co-author of the study.
Interviewing the test subjects found strong support for self-administration of the flu vaccine.
“In addition to the preference for the vaccine patch, we found that a large majority of the people willing to be vaccinated would choose to self-administer the vaccine,” said James Norman, the study’s first author, who was a Georgia Tech graduate student when the research was conducted.
Study participants were asked to assess the pain associated with administering the patch and receiving the intramuscular injection. On a scale of one to 100, they rated the patches 1.5 on average, while the injection was rated 15.
Less than half the U.S. population receives vaccination against influenza each year. Several thousand Americans die of complications from the flu each year, and as many as 200,000 are hospitalized. Increasing the immunization rate could cut the deaths, hospitalizations and costs associated with the disease, Prausnitz noted.
Use of a vaccine patch could potentially also reduce the cost of vaccination programs. For influenza, the cost of storing and administering the vaccine – along with patient time to visit a clinic – accounts for as much as three-quarters of the total cost. If microneedle vaccine patches could be produced for about the same cost as current flu vaccines, self-administration could provide significant cost savings to the nation’s health care system.
Animal studies have shown that microneedle patches are at least as good as conventional intramuscular injections at conferring immunity to influenza. Prausnitz and his research team plan to begin a Phase 1 clinical study of the vaccine patches in humans during the spring of 2015. If that study shows promise, it could lead to larger studies and development of commercial patch manufacture.
If all goes well, the vaccine patch could be available within five years. Prausnitz expects it to be administered first by health care professionals before being made available for self-administration.
In addition to those already named, the study also involved Martin I. Meltzer, senior health economist with the CDC, and two Georgia Tech researchers: Jaya M. Arya and Maxine A. McClain.
Mark Prausnitz is an inventor on patents that have been licensed to companies developing microneedle-based products, is a paid advisor to companies developing microneedle-based products, and is a founder/shareholder of companies developing microneedle-based products. This potential conflict of interest has been disclosed and is managed by Georgia Tech and Emory University.
Research on the use of microneedle patches for influenza vaccination has been supported by the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health (NIH/NIBIB), under award R01EB006369. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
CITATION: James J. Norman, et al., “Microneedle Patches: Usability and Acceptability for Self-Vaccination Against Influenza,” (Vaccine, 2014). (http://dx.doi.org/10.1016/j.vaccine.2014.01.076)
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]]>The Georgia ImmunoEngineering Consortium (GIEC) will bring together engineers, physicians, chemists, physicists, computational scientists, immunologists and clinical investigators to better understand how the immune system works and how to precisely modulate it to target challenging diseases.
The research teams will focus on cancer, infectious diseases, autoimmune and inflammatory disorders (diabetes, lupus, multiple sclerosis, arthritis, fibrosis, asthma, inflammatory bowel disease, etc.), and areas of regenerative medicine including transplantation, bone and cartilage repair, and treatments for spinal cord injuries.
“The immune system and its multi-faceted role in human health and disease form the cornerstone of medical research, says Ignacio Sanz, MD, co-chair of the consortium steering committee. Sanz is Mason I. Lowance Chair of Allergy and Immunology and director of the Lowance Center of Human Immunology at Emory, director of rheumatology in the Department of Medicine in Emory School of Medicine, and a Georgia Research Alliance Eminent Scholar.
“This consortium not only combines the expertise of researchers throughout a variety of disciplines focused on the human immune response, but also reflects an increasing focus on engineering technologies and informatics in improving the diagnosis and treatment of challenging diseases.”
“By joining our immense strengths in immunology and bioengineering, we aspire to become an international leader in immunoengineering science; develop new technologies for prevention, rapid diagnosis, and treatment of immune-related disorders and train the next generation of physicians and engineers in this cutting edge research,” says Krishnendu Roy, PhD, co-chair of the consortium steering committee, director of the Center for ImmunoEngineering in the Parker H. Petit Institute for Bioengineering and Bioscience at Georgia Tech and Carol Ann and David D. Flanagan professor of biomedical engineering in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
Immunoengineering is the application of engineering tools and principles to better understand and monitor our immune system in health and in diseases. This knowledge is then used to develop more effective vaccines and therapies against a wide range of diseases like cancer, HIV, diabetes, multiple sclerosis, arthritis etc. and also to improve tissue regeneration, wound healing and transplantation, explain Sanz and Roy.
“Game-changing innovation and world-class scholarship occur at the boundaries of fields of study where collaborators bring different perspectives to challenging problems,” says Stephen E. Cross, executive vice president for research at Georgia Tech. “This is the essence of the successful 17-year partnership between engineering and science at Georgia Tech, and medical science and clinical practice at Emory.”
Existing centers and departments that will collaborate within the new consortium include the Center for ImmunoEngineering at Georgia Tech as well as the Emory Vaccine Center, Lowance Center for Human Immunology, Departments of Medicine, Microbiology and Immunology, Hematology and Oncology, and Pathology and Laboratory Medicine in Emory School of Medicine, the Emory-Children’s Pediatric Research Center, and Winship Cancer Institute, among others.
The consortium has partnered with the Georgia Research Alliance (GRA), a nonprofit organization that expands research and commercialization capacity in Georgia’s universities to launch new companies, create high-value jobs and transform lives.
“The Georgia ImmunoEngineering Consortium is a unique academic collaboration that represents strong opportunities to align our state’s extensive university research base with targeted life sciences industry development in Georgia,” says C. Michael Cassidy, GRA president and CEO. “GRA looks forward to seeing the new discoveries and commercial opportunities that result from this partnership.”
The consortium will also collaborate with research partners at the Centers for Disease Control and Prevention (CDC) and partners at various colleges and universities around Georgia, the United States, and around the world.
“Using engineering approaches to help unlock the biology of the immune system opens the door for exciting new discoveries that can alter human disease,” says David S. Stephens MD, vice president for research in Emory’s Woodruff Health Sciences Center, chair of the Department of Medicine in Emory University School of Medicine, and a member of the consortium steering committee.
Additional members of the steering committee from Georgia Tech include M.G. Finn and Susan Thomas, and from Emory include Rafi Ahmed and Edmund K. (Ned) Waller.
A symposium will celebrate the consortium launch:
Georgia ImmunoEngineering Symposium:
Feb. 28, 2014, 7 a.m. – 5 p.m.
Emory Conference Center
For more information about the consortium, please view the website.
- Holly Korschun, Emory University
]]>Research News
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]]>Research reported this week shows that electrical resistance in nanoribbons of epitaxial graphene changes in discrete steps following quantum mechanical principles. The research shows that the graphene nanoribbons act more like optical waveguides or quantum dots, allowing electrons to flow smoothly along the edges of the material. In ordinary conductors such as copper, resistance increases in proportion to the length as electrons encounter more and more impurities while moving through the conductor.
The ballistic transport properties, similar to those observed in cylindrical carbon nanotubes, exceed theoretical conductance predictions for graphene by a factor of 10. The properties were measured in graphene nanoribbons approximately 40 nanometers wide that had been grown on the edges of three-dimensional structures etched into silicon carbide wafers.
“This work shows that we can control graphene electrons in very different ways because the properties are really exceptional,” said Walt de Heer, a Regent’s professor in the School of Physics at the Georgia Institute of Technology. “This could result in a new class of coherent electronic devices based on room temperature ballistic transport in graphene. Such devices would be very different from what we make today in silicon.”
The research, which was supported by the National Science Foundation, the Air Force Office of Scientific Research and the W.M. Keck Foundation, was reported February 5 in the journal Nature. The research was done through a collaboration of scientists from Georgia Tech in the United States, Leibniz Universität Hannover in Germany, the Centre National de la Recherche Scientifique (CNRS) in France and Oak Ridge National Laboratory – supported by the Department of Energy – in the United States.
For nearly a decade, researchers have been trying to use the unique properties of graphene to create electronic devices that operate much like existing silicon semiconductor chips. But those efforts have met with limited success because graphene – a lattice of carbon atoms that can be made as little as one layer thick – cannot be easily given the electronic bandgap that such devices need to operate.
De Heer argues that researchers should stop trying to use graphene like silicon, and instead use its unique electron transport properties to design new types of electronic devices that could allow ultra-fast computing – based on a new approach to switching. Electrons in the graphene nanoribbons can move tens or hundreds of microns without scattering.
“This constant resistance is related to one of the fundamental constants of physics, the conductance quantum,” de Heer said. “The resistance of this channel does not depend on temperature, and it does not depend on the amount of current you are putting through it.”
What does disrupt the flow of electrons, however, is measuring the resistance with an electrical probe. The measurements showed that touching the nanoribbons with a single probe doubles the resistance; touching it with two probes triples the resistance.
“The electrons hit the probe and scatter,” explained de Heer. “It’s a lot like a stream in which water is flowing nicely until you put rocks in the way. We have done systematic studies to show that when you touch the nanoribbons with a probe, you introduce a method for the electrons to scatter, and that changes the resistance.”
The nanoribbons are grown epitaxially on silicon carbon wafers into which patterns have been etched using standard microelectronics fabrication techniques. When the wafers are heated to approximately 1,000 degrees Celsius, silicon is preferentially driven off along the edges, forming graphene nanoribbons whose structure is determined by the pattern of the three-dimensional surface. Once grown, the nanoribbons require no further processing.
The advantage of fabricating graphene nanoribbons this way is that it produces edges that are perfectly smooth, annealed by the fabrication process. The smooth edges allow electrons to flow through the nanoribbons without disruption. If traditional etching techniques are used to cut nanoribbons from graphene sheets, the resulting edges are too rough to allow ballistic transport.
“It seems that the current is primarily flowing on the edges,” de Heer said. “There are other electrons in the bulk portion of the nanoribbons, but they do not interact with the electrons flowing at the edges.”
The electrons on the edge flow more like photons in optical fiber, helping them avoid scattering. “These electrons are really behaving more like light,” he said. “It is like light going through an optical fiber. Because of the way the fiber is made, the light transmits without scattering.”
The researchers measured ballistic conductance in the graphene nanoribbons for up to 16 microns. Electron mobility measurements surpassing one million correspond to a sheet resistance of one ohm per square that is two orders of magnitude lower than what is observed in two-dimensional graphene – and ten times smaller than the best theoretical predictions for graphene.
“This should enable a new way of doing electronics,” de Heer said. “We are already able to steer these electrons and we can switch them using rudimentary means. We can put a roadblock, and then open it up again. New kinds of switches for this material are now on the horizon.”
Theoretical explanations for what the researchers have measured are incomplete. De Heer speculates that the graphene nanoribbons may be producing a new type of electronic transport similar to what is observed in superconductors.
“There is a lot of fundamental physics that needs to be done to understand what we are seeing,” he added. “We believe this shows that there is a real possibility for a new type of graphene-based electronics.”
Georgia Tech researchers have pioneered graphene-based electronics since 2001, for which they hold a patent, filed in 2003. The technique involves etching patterns into electronics-grade silicon carbide wafers, then heating the wafers to drive off silicon, leaving patterns of graphene.
In addition to de Heer, the paper’s authors included Jens Baringhaus, Frederik Edler and Christoph Tegenkamp from the Institut für Festkörperphysik, Leibniz Universität, Hannover in Germany; Edward Conrad, Ming Ruan and Zhigang Jiang from the School of Physics at Georgia Tech; Claire Berger from Georgia Tech and Institut Néel at the Centre National de la Recherche Scientifique (CNRS) in France; Antonio Tejeda and Muriel Sicot from the Institut Jean Lamour, Universite de Nancy, Centre National de la Recherche Scientifique (CNRS) in France; An-Ping Li from the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory, and Amina Taleb-Ibrahimi from the CNRS Synchotron SOLEIL in France.
This research was supported by the National Science Foundation (NSF) Materials Research Science and Engineering Center (MRSEC) at Georgia Tech through award DMR-0820382; the Air Force Office of Scientific Research (AFOSR); the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy, and the Partner University Fund from the Embassy of France. Any conclusions or recommendations are those of the authors and do not necessarily represent the official views of the NSF, DOE or AFOSR.
CITATION: Jens Baringhaus, et al., “Exceptional ballistic transport in epitaxial graphene nanoribbons,” (Nature 2013). (http://dx.doi.org/10.1038/nature12952).
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]]>As part of the acquisition, the 10 staff and management team members of the Computer-Aided Structural Engineering Center (CASE Center) at Georgia Tech have joined Intergraph. Developed by the CASE Center within the School of Civil and Environmental Engineering, GT STRUDL integrates graphical modeling, frame and finite element linear and nonlinear static and dynamic analysis, structural frame design, graphical analysis and design result display and structural database management all into a menu-driven information processing system.
GT STRUDL is widely used in a variety of industries such as nuclear power and nuclear defense industries, conventional power generation, general plant structures, offshore structures, marine applications, general civil engineering and infrastructure structures. GT STRUDL is currently used by thousands of structural engineers in engineering enterprises, government agencies and universities in more than 40 countries throughout the world.
In the United States nuclear industry, for instance, GT STRUDL is widely used by major companies in the design, maintenance and upgrading of safety-critical structures such as turbine buildings, boiler buildings, equipment support structures, pipe support systems and other related civil engineering structures.
Intergraph, based in Huntsville, Ala., will provide current GT STRUDL licensees with uninterrupted support, maintenance and software upgrades as part of their maintenance agreements.
“With the acquisition of GT STRUDL and its skilled and experienced R&D team, Intergraph gains a successful and well-established structural analysis and design program, heavily focused on the growing global nuclear power, general plant design, and offshore industry markets,” said Gerhard Sallinger, president of Intergraph Process, Power & Marine. Intergraph (www.intergraph.com) is part of Hexagon (www.hexagon.com), a leading global provider of design, measurement and visualization technologies
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]]>Instead of invading new areas, the migrating cells latch onto the specially-designed nanofibers and follow them to a location – potentially outside the brain – where they can be captured and killed. Using this technique, researchers can partially move tumors from inoperable locations to more accessible ones. Though it won’t eliminate the cancer, the new technique reduced the size of brain tumors in animal models, suggesting that this form of brain cancer might one day be treated more like a chronic disease.
“We have designed a polymer thin film nanofiber that mimics the structure of nerves and blood vessels that brain tumor cells normally use to invade other parts of the brain,” explained Ravi Bellamkonda, lead investigator and chair of the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “The cancer cells normally latch onto these natural structures and ride them like a monorail to other parts of the brain. By providing an attractive alternative fiber, we can efficiently move the tumors along a different path to a destination that we choose.”
Details of the technique were reported February 16 in the journal Nature Materials. The research was supported by the National Cancer Institute (NCI), part of the National Institutes of Health; by Atlanta-based Ian’s Friends Foundation, and by the Georgia Research Alliance. In addition to the Coulter Department of Biomedical Engineering, the research team included Children’s Healthcare of Atlanta and Emory University.
Treating the Glioblastoma multiforme cancer, also known as GBM, is difficult because the aggressive and invasive cancer often develops in parts of the brain where surgeons are reluctant to operate. Even if the primary tumor can be removed, however, it has often spread to other locations before being diagnosed.
New drugs are being developed to attack GBM, but the Atlanta-based researchers decided to take a more engineering approach. Anjana Jain, who is the first author of this GBM study, is now an assistant professor in the Department of Biomedical Engineering at Worcester Polytechnic Institute in Massachusetts. As a Georgia Tech graduate student, Jain worked on biomaterials for spinal cord regeneration. Then, as a postdoctoral fellow in the Bellamkonda lab, she saw the opportunity to apply her graduate work to develop potential new treatment modalities for GBM.
“The signaling pathways we were trying to activate to repair the spinal cord were the same pathways researchers would like to inactivate for glioblastomas,” said Jain. “Moving into cancer applications was a natural progression, one that held great interest because of the human toll of the disease.”
Tumor cells typically invade healthy tissue by secreting enzymes that allow the invasion to take place, she explained. That activity requires a significant amount of energy from the cancer cells.
“Our idea was to give the tumor cells a path of least resistance, one that resembles the natural structures in the brain, but is attractive because it does not require the cancer cells to expend any more energy,” she explained.
Experimentally, the researchers created fibers made from polycaprolactone (PCL) polymer surrounded by a polyurethane carrier. The fibers, whose surface simulates the contours of nerves and blood vessels that the cancer cells normally follow, were implanted into the brains of rats in which a human GBM tumor was growing. The fibers, just half the diameter of a human hair, served as tumor guides, leading the migrating cells to a “tumor collector” gel containing the drug cyclopamine, which is toxic to cancer cells. For comparison, the researchers also implanted fibers containing no PCL or an untextured PCL film in other rat brains, and left some rats untreated. The tumor collector gel was located physically outside the brain.
After 18 days, the researchers found that compared to other rats, tumor sizes were substantially reduced in animals that had received the PCL nanofiber implants near the tumors. Tumor cells had moved the entire length of all fibers into the collector gel outside the brain.
While eradicating a cancer would always be the ideal treatment, Bellamkonda said, the new technique might be able to control the growth of inoperable cancers, allowing patients to live normal lives despite the disease.
“If we can provide cancer an escape valve of these fibers, that may provide a way of maintaining slow-growing tumors such that, while they may be inoperable, people could live with the cancers because they are not growing,” he said. “Perhaps with ideas like this, we may be able to live with cancer just as we live with diabetes or high blood pressure.”
Before the technique can be used in humans, however, it will have to undergo extensive testing and be approved by the FDA – a process that can take as much as ten years. Among the next steps are to evaluate the technique with other forms of brain cancer, and other types of cancer that can be difficult to remove.
Treating brain cancer with nanofibers could be preferable to existing drug and radiation techniques, Bellamkonda said.
“One attraction about the approach is that it is purely a device,” he explained. “There are no drugs entering the blood stream and circulating in the brain to harm healthy cells. Treating these cancers with minimally-invasive films could be a lot less dangerous than deploying pharmaceutical chemicals.”
Seed funding for early research to verify the potential for the technique was sponsored by Ian’s Friends Foundation, an Atlanta-based organization that supports research into childhood brain cancers.
"We couldn't be more thrilled with the progress that Georgia Tech and Professor Bellamkonda's lab have made in helping find a solution for children with both inoperable brain tumors and for those suffering with tumors in more invasive areas,” said Phil Yagoda, one of the organization’s founders. “With this research team’s dedication and vision, this exciting and exceptional work is now closer to reality. By enabling the movement of an inoperable tumor to an operable spot, this work could give hope to all the children and parents of those children fighting their greatest fight, the battle for their lives."
In addition to those already mentioned, the research team included Barunashish Brahma from the Department of Neurosurgery at Children’s Healthcare of Atlanta; Tobey MacDonald from the Department of Pediatrics at Emory University School of Medicine, and Martha Betancur, Gaurangkuma Patel, Chandra Valmikinathan, Vivek Mukhatyar, Ajit Vakharia and S. Balakrishna Pai from the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
This research was supported by the National Cancer Institute of the National Institutes of Health (NIH) through EUREKA award number R01-CA153229. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the NIH.
CITATION: Anjana Jain, et al., “Guiding intracortical brain tumour cells to an extracortical cytotoxic hydrogel using aligned polymeric nanofibres,” (Nature Materials, 2014). (http://dx.doi.org/10.1038/nmat3878).
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]]>Now, researchers at the Georgia Institute of Technology have developed a new type of low-temperature fuel cell that directly converts biomass to electricity with assistance from a catalyst activated by solar or thermal energy. The hybrid fuel cell can use a wide variety of biomass sources, including starch, cellulose, lignin – and even switchgrass, powdered wood, algae and waste from poultry processing.
The device could be used in small-scale units to provide electricity for developing nations, as well as for larger facilities to provide power where significant quantities of biomass are available.
“We have developed a new method that can handle the biomass at room temperature, and the type of biomass that can be used is not restricted – the process can handle nearly any type of biomass,” said Yulin Deng, a professor in Georgia Tech’s School of Chemical and Biomolecular Engineering and the Institute of Paper Science and Technology (IPST). “This is a very generic approach to utilizing many kinds of biomass and organic waste to produce electrical power without the need for purification of the starting materials.”
The new solar-induced direct biomass-to-electricity hybrid fuel cell was described February 7, 2014, in the journal Nature Communications.
The challenge for biomass fuel cells is that the carbon-carbon bonds of the biomass – a natural polymer – cannot be easily broken down by conventional catalysts, including expensive precious metals, Deng noted. To overcome that challenge, scientists have developed microbial fuel cells in which microbes or enzymes break down the biomass. But that process has many drawbacks: power output from such cells is limited, microbes or enzymes can only selectively break down certain types of biomass, and the microbial system can be deactivated by many factors.
Deng and his research team got around those challenges by altering the chemistry to allow an outside energy source to activate the fuel cell’s oxidation-reduction reaction.
In the new system, the biomass is ground up and mixed with a polyoxometalate (POM) catalyst in solution and then exposed to light from the sun – or heat. A photochemical and thermochemical catalyst, POM functions as both an oxidation agent and a charge carrier. POM oxidizes the biomass under photo or thermal irradiation, and delivers the charges from the biomass to the fuel cell’s anode. The electrons are then transported to the cathode, where they are finally oxidized by oxygen through an external circuit to produce electricity.
“If you mix the biomass and catalyst at room temperature, they will not react,” said Deng. “But when you expose them to light or heat, the reaction begins. The POM introduces an intermediate step because biomass cannot be directly accessed by oxygen.”
The system provides major advantages, including combining the photochemical and solar-thermal biomass degradation in a single chemical process, leading to high solar conversion and effective biomass degradation. It also does not use expensive noble metals as anode catalysts because the fuel oxidation reactions are catalyzed by the POM in solution. Finally, because the POM is chemically stable, the hybrid fuel cell can use unpurified polymeric biomass without concern for poisoning noble metal anodes.
The system can use soluble biomass, or organic materials suspended in a liquid. In experiments, the fuel cell operated for as long as 20 hours, indicating that the POM catalyst can be re-used without further treatment.
In their paper, the researchers reported a maximum power density of 0.72 milliwatts per square centimeter, which is nearly 100 times higher than cellulose-based microbial fuel cells, and near that of the best microbial fuel cells. Deng believes the output can be increased five to ten times when the process is optimized.
“I believe this type of fuel cell could have an energy output similar to that of methanol fuel cells in the future,” he said. “To optimize the system, we need to have a better understanding of the chemical processes involved and how to improve them.”
The researchers also need to compare operation of the system with solar energy and other forms of input energy, such as waste heat from other processes. Beyond the ability to directly use biomass as a fuel, the new cell also offers advantages in sustainability – and potentially lower cost compared to other fuel cell types.
“We can use sustainable materials without any chemical pollution,” Deng said. “Solar energy and biomass are two important sustainable energy sources available to the world today. Our system would use them together to produce electricity while reducing dependence on fossil fuels.”
In addition to Deng, the research team included Wei Liu, Wei Mu, Mengjie Liu, Xiaodan Zhang and Hongli Cai, all from the School of Chemical and Biomolecular Engineering or the Institute of Paper Science and Technology at Georgia Tech.
CITATION: Wei Liu, et al., “Solar-induced direct biomass-to-electricity hybrid fuel cell using polyoxometalates as photocatalyst and charge carrier,” (Nature Communications, 2014). (http://www.dx.doi.org/10.1038/ncomms4208).
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]]>The device integrates ultrasound transducers with processing electronics on a single 1.4 millimeter silicon chip. On-chip processing of signals allows data from more than a hundred elements on the device to be transmitted using just 13 tiny cables, permitting it to easily travel through circuitous blood vessels. The forward-looking images produced by the device would provide significantly more information than existing cross-sectional ultrasound.
Researchers have developed and tested a prototype able to provide image data at 60 frames per second, and plan next to conduct animal studies that could lead to commercialization of the device.
“Our device will allow doctors to see the whole volume that is in front of them within a blood vessel,” said F. Levent Degertekin, a professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. “This will give cardiologists the equivalent of a flashlight so they can see blockages ahead of them in occluded arteries. It has the potential for reducing the amount of surgery that must be done to clear these vessels.”
Details of the research were published online in the February 2014 issue of the journal IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. Research leading to the device development was supported by the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health.
“If you’re a doctor, you want to see what is going on inside the arteries and inside the heart, but most of the devices being used for this today provide only cross-sectional images,” Degertekin explained. “If you have an artery that is totally blocked, for example, you need a system that tells you what’s in front of you. You need to see the front, back and sidewalls altogether. That kind of information is basically not available at this time.”
The single chip device combines capacitive micromachined ultrasonic transducer (CMUT) arrays with front-end CMOS electronics technology to provide three-dimensional intravascular ultrasound (IVUS) and intracardiac echography (ICE) images. The dual-ring array includes 56 ultrasound transmit elements and 48 receive elements. When assembled, the donut-shaped array is just 1.5 millimeters in diameter, with a 430-micron center hole to accommodate a guide wire.
Power-saving circuitry in the array shuts down sensors when they are not needed, allowing the device to operate with just 20 milliwatts of power, reducing the amount of heat generated inside the body. The ultrasound transducers operate at a frequency of 20 megahertz (MHz).
Imaging devices operating within blood vessels can provide higher resolution images than devices used from outside the body because they can operate at higher frequencies. But operating inside blood vessels requires devices that are small and flexible enough to travel through the circulatory system. They must also be able to operate in blood.
Doing that requires a large number of elements to transmit and receive the ultrasound information. Transmitting data from these elements to external processing equipment could require many cable connections, potentially limiting the device’s ability to be threaded inside the body.
Degertekin and his collaborators addressed that challenge by miniaturizing the elements and carrying out some of the processing on the probe itself, allowing them to obtain what they believe are clinically-useful images with only 13 cables.
“You want the most compact and flexible catheter possible,” Degertekin explained. “We could not do that without integrating the electronics and the imaging array on the same chip.”
Based on their prototype, the researchers expect to conduct animal trials to demonstrate the device’s potential applications. They ultimately expect to license the technology to an established medical diagnostic firm to conduct the clinical trials necessary to obtain FDA approval.
For the future, Degertekin hopes to develop a version of the device that could guide interventions in the heart under magnetic resonance imaging (MRI). Other plans include further reducing the size of the device to place it on a 400-micron diameter guide wire.
In addition to Degertekin, the research team included Jennifer Hasler, a professor in the Georgia Tech School of Electrical and Computer Engineering; Mustafa Karaman, a professor at Istanbul Technical University; Coskun Tekes, a postdoctoral fellow in the Woodruff School of Mechanical Engineering; Gokce Gurun and Jaime Zahorian, recent graduates of Georgia Tech’s School of Electrical and Computer Engineering, and Georgia Tech Ph.D. students Toby Xu and Sarp Satir.
This research was supported by award number R01EB010070 from the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health (NIH). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIBIB or NIH.
CITATION: Gokce Gurun, et al., “Single-Chip CMUT-on-CMOS Front-end System for Real-Time Volumetric IVUS and ICE Imaging,” (IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2014). (http://dx.doi.org/10.1109/TUFFC.2014.6722610).
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]]>What ensued that day was a cascade of failures throughout the northeastern United States and southeastern Canada. In all, 50 million customers lost power for up to two days. For many, this blackout served as a wake-up call to the fragility of the electric energy grid.
More than 10 years later, our electric power system continues to be challenged. In the United States, 149 power outages affecting at least 50,000 customers occurred between 2000 and 2004, a number which grew to 349 between 2005 and 2009. In 2012, the prolonged power outages in New York and New Jersey caused by Hurricane Sandy once again demonstrated the system’s vulnerability.
The demands of our digital society are increasing. What’s more, our need to accommodate renewable energy generation is rising, and threats to infrastructure security and concerns over global climate change are growing. To help address these concerns, Georgia Tech is conducting research that crosses many disciplines, including electrical and computer engineering, public policy, mechanical engineering and information security.
Revolutionizing the Delivery of Electricity
The electricity grid is a large, complex system of power generation, transmission and distribution. High-voltage transmission lines carry power from large power plants to load centers hundreds of miles away. Next, lower-voltage distribution systems draw electricity from the transmission lines and distribute it to individual customers.
This long-standing electricity paradigm is phasing out as advancements to the grid essentially make it “smarter.” Smart grids are equipped with advanced sensing, communication, and control systems that will allow unprecedented interaction between electricity providers and consumers. The smart grid will integrate renewable energy sources and allow a new class of utility customers to be both providers and consumers of power.
Georgia Tech: Advancing the Smart Grid
The potential of the smart grid is enormous: improved energy efficiency, optimization of power supply and demand, and greater transparency into power consumption.
Georgia Tech researchers across several disciplines are helping to advance the smart grid by developing technologies, creating methodologies and analyzing policies.
Thwarting Blackouts
A phenomenon called a “voltage collapse” can cause a blackout when electricity demands reach a critical level, even if there is sufficient power generation to meet the demand. The Northeast Blackout of 2003 led utilities and the government to team up to install a phasor network throughout the United States.
By placing phasor measurement units at critical points in the network, operators can assess system stress. Miroslav Begovic, a professor in the School of Electrical and Computer Engineering, helped to develop a methodology that uses the data collected from phasor measurement units. System operators can quickly assess the state of the power system and determine in real time whether it is in danger of a blackout.
Integrating Renewable Energy Sources
Wind, sun, water, wood, organic waste, and geothermal energy generated about 12 percent of the electricity in the United States in 2012.
Georgia Tech’s School of Electrical and Computer Engineering, H. Milton Stewart School of Industrial and Systems Engineering, Strategic Energy Institute, and School of Mechanical Engineering are working together to allow expansion of this percentage. Researcher teams are developing a more distributed and flexible control architecture that supports high levels of renewable energy generation and storage. In addition, they are studying market mechanisms that balance supply and demand in the presence of these energy sources.
This new architecture is based on the emerging concept of “prosumers” — a combination of the words “consumer” and “producer” — which are economically motivated small-scale energy ecosystems that can consume, produce and store electricity. For example, prosumers could include homeowners who consume electricity from the grid while also producing power onsite from solar panels on their homes’ roofts that feeds back into the grid.
Analyzing Energy Policies
In recent years, several U.S. states, the federal government and other countries have adopted or are considering laws, regulations, programs, and requirements aimed at improving power systems.
Researchers from Georgia Tech’s Sam Nunn School of International Affairs and School of Economics are analyzing and recommending policies that promote the path toward the next generation of the electric utility grid.
Securing Utilities from Cyber Attacks
In addition to asset management concerns, utilities are also worried about cyber threats. A National Research Council report warned that a coordinated strike on the electric grid could have devastating effects on the American economy. Georgia Tech researchers have helped secure and protect devices throughout U.S. government and corporate networks for years.
To help prevent cyber attacks, the Georgia Tech Research Institute, National Electric Energy Testing, Research and Applications Center and the Strategic Energy Institute are working with experts in smart grid technology to develop tools that can detect weaknesses.
What’s Next?
Technical, regulatory and financial obstacles have slowed its worldwide adoption, and it is estimated to take decades for the entire grid renovation. Georgia Tech researchers continue their development of this transformative technology and the smart grid momentum is growing. In fact, smart grid technology is already a reality in several U.S. cities.
Learn More About the Smart Grid:
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]]>In the research, microchips were coated with a thin layer of endothelial cells, which make up the interior surface of blood vessels. In healthy blood vessels, endothelial cells act as a barrier to keep foreign objects out of the bloodstream. But at sites prone to atherosclerosis, the endothelial barrier breaks down, allowing things to move in and out of arteries that shouldn’t.
In a new study, nanoparticles were able to cross the endothelial cell layer on the microchip under conditions that mimic the permeable layer in atherosclerosis. The results on the microfluidic device correlated well with nanoparticle accumulation in the arteries of an animal model with atherosclerosis, demonstrating the device’s capability to help screen nanoparticles and optimize their design.
“It’s a simple model — a microchip, not cell culture dish — which means that a simple endothelialized microchip with microelectrodes can show some yet important prediction of what’s happening in a large animal model,” said YongTae (Tony) Kim, an assistant professor in bioengineering in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology.
The research was published in January online in the journal Proceedings of the National Academy of Sciences. This work represents a multidisciplinary effort of researchers that are collaborating within the Program of Excellence in Nanotechnology funded by the National Heart, Lung, and Blood Institute, the National Institutes of Health (NIH). The team includes researchers at the David H. Koch Institute for Integrative Cancer Research at MIT, the Icahn School of Medicine at Mount Sinai, the Academic Medical Center in Amsterdam, Kyushu Institute of Technology in Japan, and the Boston University School of Medicine and Harvard Medical School.
Kim began the work as his post-doctoral fellow at the Massachusetts Institute of Technology (MIT) in the lab of Robert Langer.
“This is a wonderful example of developing a novel nanotechnology approach to address an important medical problem,” said Robert Langer, the David H. Koch Institute Professor at Massachusetts Institute of Technology, who is renowned for his work in tissue engineering and drug delivery.
Kim and Langer teamed up with researchers from Icahn School of Medicine at Mount Sinai in New York. Mark Lobatto, co-lead author works in the laboratories of Willem Mulder, an expert in cardiovascular nanomedicine and Zahi Fayad, the director of Mount Sinai’s Translational and Molecular Imaging Institute.
“The work represents a unique integration of microfluidic technology, cardiovascular nanomedicine, vascular biology and in vivo imaging. We now better understand how nanoparticle targeting in atherosclerosis works.” Lobatto says.
The researchers hope that their microchip can accelerate the nanomedicine development process by better predicting therapeutic nanoparticles’ performance in larger animal models, such as rabbits. Such a complimentary in vitro model would save time and money and require fewer animals.
Few nanoparticle-based drug delivery systems, compared to proposed studies, have been approved by the U.S. Food and Drug Administration, Kim said. The entire process developing one nanomedicine platform can take 15 years to go from idea to synthesis to testing in vitro to testing in vivo to approval.
“That’s a frustrating process,” Kim said. “Often what works in cell culture dishes doesn’t work in animal models.”
To help speed up nanomedicine research by improving the predictive capabilities of in vitro testing, Kim and colleagues designed their microchip to mimic what’s going on in the body better than what is currently possible through routine cell culture.
“In the future, we can make microchips that are much more similar to what’s going on in animal models, or even human beings, compared to the conventional cell culture dish studies,” Kim said.
On their microchip, scientists can control the permeability of the endothelial cell layer by altering the rate of blood flow across the cells or by introducing a chemical that is released by the body during inflammation. The researchers discovered that the permeability of the cells on the microchip correlated well with the permeability of microvessels in a large animal model of atherosclerosis.
The microchips allows for precise control of the mechanical and chemical environment around the living cells. By using the microchip, the researchers can create physiologically relevant conditions to cells by altering the rate of blood flow across the cells or by introducing a chemical that is released by the body during inflammation.
Kim said that while this microchip-based system offers better predictability than current cell culture experiments, it won’t replace the need for the animal studies, which provide a relatively more complete picture of how well a particular nanomedicine might work in humans.
“This is better than an in vitro dish experiment, but it’s not going to perfectly replicate what’s going on inside the body in near future,” Kim said. “It will help make this whole process faster and save a number of animals.”
This research is supported by the National Heart, Lung, and Blood Institute as a Program of Excellence in Nanotechnology Award (HHSN268201000045C), the National Cancer Institute (NCI) (CA151884); the David H. Koch Prostate Cancer Foundation Award in Nanotherapeutics, and the National Institutes of Health (NIH) (R01 EB009638 and R01CA155432). Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: YongTae Kim, et al., “Probing nanoparticle translocation across the permeable endothelium in experimental atherosclerosis,” (PNAS, January 2014). (http://dx.doi.org/10.1073/pnas.1322725111).
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]]>A team from the Georgia Tech Research Institute (GTRI) has produced an advanced web-based tool that lets physically separated participants collaborate on model-based systems engineering projects. Known as the Framework for Assessing Cost and Technology (FACT), the program utilizes open-source software components to allow users to visualize a system's potential expense alongside its performance, reliability and other factors.
The research is sponsored by the U.S. Marine Corps Systems Command (MCSC). The work was most recently reported in March in the Proceedings of the 11th Conference on Systems Engineering Research.
The FACT tool enables users to pull all aspects of a project into a single modeling and simulation process, explained Tommer Ender, a GTRI senior research engineer who co-leads the effort.
"The FACT framework lets multiple users work together online to create entire systems, including complex technology systems," Ender said. "All they need is access to a web browser."
FACT's features include:
FACT is currently in use at the GTRI field office in Quantico, Va., located on the Quantico Marine Corps Base. There, senior research engineers Jim Bertoglio and Ron Smith are working with Marine Corps personnel to maximize the software's effectiveness.
Inside the GTRI facility, a dedicated conference room with six large high definition screens provides highly reconfigurable work areas. The screens function individually or together, while notes handwritten on a linked screen can instantly become electronic text that supports the online collaboration.
Modeling Multiple Factors
Modeling and simulation software, Ender explained, has traditionally been used to address performance issues. For instance, M&S tools allow researchers to investigate the capabilities of air or ground vehicles, or radar systems' effectiveness against hostile action.
"These tools do an excellent job of answering the 'how fast, how well' questions, but we rarely see them working in either collaborative or cost-aware environments," he said.
With FACT, online users can take advantage of a technique called trade-space analysis, which allows them to juggle performance, cost and other factors, said Daniel Browne, a research engineer who leads the project for GTRI. For example, users examining vehicle convoy logistics could investigate the complex interrelationship of vehicles, personnel, supplies and cost to pinpoint optimal combinations.
"We can select parameters for each component down to the desired level of detail, and then experiment with trade-offs at the attribute level," Browne said. "Suppose I use FACT to adjust the number of convoy personnel per HUMVEE to increase fuel efficiency. I can then turn around and look at how that change affects the number of convoys I can field, and what the ultimate cost savings is."
FACT's collaborative capabilities include security and usability functions that are highly configurable, he said. If, for instance, a given user is responsible only for budgetary considerations, administrators could limit that person to just the model's cost portions.
Users can create entire technical models outside the FACT framework, and then introduce those models into the collaborative arena for team-wide consideration. In all cases, administrators can go back and trace each part of the work, including where it came from and what happened after it came into the system.
A Multi-Project Tool
Ender stressed the point that FACT's modeling capabilities can be applied to many different types of projects. The GTRI development team has already used it to address systems engineering questions relating to ships, satellites and ground vehicles.
"In the past, it's been very challenging to re-use modeling and simulation tools," he said. "You could build a big beautiful tool for a customer, but when the customer came in with a different problem, you had to start again from scratch."
A major factor in FACT's portability is that its building blocks are both flexible and familiar. They're based on open-source software standards and recognized approaches to systems engineering processes.
For instance, the FACT toolkit utilizes the Systems Modeling Language (SysML), an open-source modeling language widely used in systems engineering applications. SysML supports design, analysis and validation of many different kinds of systems development.
The FACT tool itself will likely be limited to military use, Browne said. But software frameworks similar to FACT offer promise for future applications that could support both academic and commercial systems engineering needs.
"The ultimate goal is to have a reusable model-based systems engineering tool in hand, available for a wide range of customer needs," he said. "Having such a tool lets us spend our time and effort improving the quality of the domain-specific information that goes into the model itself, rather than having to reinvent the modeling tool we're using."
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]]>Understanding the controls on and the stability of this ocean circulation system could help scientists better assess this system’s vulnerability to future climate change.
These major iceberg surges are known as Heinrich events. While the study found evidence that some Heinrich events had a major impact on the system of ocean currents that transfer heat from the Southern to the Northern Hemisphere (Atlantic Meridional Overturning Circulation, or AMOC), the study found little evidence of major changes to the AMOC for two of the Heinrich Events that occurred earlier, at the height of the last ice age, at about 24,000 and 31,000 years ago.
“That’s surprising, you would expect to see disruption for all of the Heinrich events,” said Jean Lynch-Stieglitz, a professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology in Atlanta, and the study’s lead author. “We just didn’t see any indication that anything out of the ordinary was going on during those previous Heinrich events.”
The study was published January 12 in the journal Nature Geoscience and was supported by the National Science Foundation (NSF). One of the paper’s co-authors, L. Gene Henry, was an undergraduate at Georgia Tech during the research project.
The study’s findings suggest that the broader climate changes seen at the time of the Heinrich events — changes in precipitation at lower latitudes, for example — may not be linked in a direct, simple way to the AMOC.
To examine the impact of Heinrich events on this ocean circulation, the researchers travelled to the Florida Straits, where they took sediment cores from the ocean floor. They analyzed the fossilized shells of a bottom dwelling single celled organisms (foraminifera) for specific oxygen and carbon isotope ratios. These isotopes provide valuable information about the properties of the seawater in the Florida Straits at the time when these small shells were formed over the past 35,000 years.
“Surprisingly, it’s been very, very difficult to get good records of the past variability of the overturning circulation on these time scales,” Lynch-Stieglitz said.
Previous studies have examined the influence of Heinrich events on the AMOC, but the results have been conflicting. Most of the previous studies examined carbon isotopes in deep water foraminifera. Lynch-Stieglitz’s team used a new approach to the problem by examining the upper part of the overturning circulation. The research team also used computer models to show the sensitivity of the seawater properties at these shallower depths to changes in ocean circulation.
“Understanding the controls on and the stability of this circulation system will ultimately help scientists to better assess the AMOC’s vulnerability to future climate change,” Lynch-Stieglitz said.
This research is supported by the National Science Foundation (NSF) under award number OCE-0096472, OCE-0648258, and OCE-1102743. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the NSF.
CITATION: Jean Lynch-Stieglitz, et al., "Muted change in Atlantic overturning circulation over some glacial-aged Heinrich Events," (Nature Geoscience, January 2014). (http://dx.doi.org/10.1038/NGEO2045).
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]]>But after talking with more than a hundred potential users of the device, she learned the real need was for a generic interface system able to connect a wide range of input devices – big button switches, joysticks, sip-and-puff straws and others – to the tablet computers. And it turned out that the market was much larger than Howard imagined, extending to adults with disabilities and potentially even persons with Alzheimer’s.
A professor in the Georgia Tech School of Electrical and Computer Engineering, Howard has now launched a company, Zyrobotics, to commercialize the device, and a prototype has already been developed. The company, run by a former graduate student, won’t be the next IBM, but it will help disabled children do what all kids want to do: play video games and interact with computers.
Assistance with refining the device came through the Innovation Corps (I-Corps™), a National Science Foundation program that helps NSF-funded researchers learn about starting up a company – and by talking to potential customers, determine whether there’s really a market for what they’ve developed.
“Without I-Corps, I wouldn’t have thought to pursue this,” said Howard, who holds the title of Motorola Foundation Professor. “They showed us how to talk about the technology in terms that the general public could understand. And I-Corps made us take a step back and ask if what we had developed was really of value to potential customers.”
I-Corps Innovation
A dozen Georgia Tech teams – each composed of a faculty member, entrepreneurial lead and industry mentor – have now gone through the six-week I-Corps program. About a third of them have, like Howard, revised their plans and decided to move forward with forming a company and creating a product based on the results of NSF-supported research. The program is part of a national effort to turn research discoveries into new companies and new products, supporting economic development and building understanding of what it means to be an entrepreneur.
“Through the Innovation Corps, NSF seeks to accelerate the development of new technologies, products and processes that arise from fundamental research,” said Rathindra (Babu) DasGupta, the NSF’s program director for I-Corps. “The goals of I-Corps are to spur translation of fundamental research, to encourage collaboration between academia and industry, and to train students to understand innovation and entrepreneurship.”
The program provides mentoring and funding designed to move the results of NSF-supported research through the early stages of company formation. “NSF investments strategically strengthen the nation’s innovation ecosystem by addressing the challenges inherent in the early stages of the innovation process,” DasGupta added.
I-Corps at Georgia Tech
Because of its long experience with forming companies from university research, in July 2012 Georgia Tech was selected to be among the first institutions to become ”nodes” teaching the I-Corps curriculum. The program is basically a boot camp that shows what it’s like to form a startup company – and ensures that there’s a real market for a fledgling company’s proposed product. About 25 teams from universities around the country participate each time the program is taught at one of the I-Corps nodes, including Georgia Tech.
“The I-Corps process is very similar to the scientific method, which scientists and engineers are familiar with,” explained Keith McGreggor, who directs the I-Corps program at Georgia Tech. “We use this process to turn fiction – what you might think is true – into fact by doing experiments and testing hypotheses in the real world with customers instead of in the laboratory.”
I-Corps puts faculty members and graduate students through a pressure cooker environment that simulates a real startup. Not everyone is cut out for entrepreneurship, McGreggor noted. Faculty members often have a skill set – collaborating with other researchers, teaching students and publishing papers – that’s different from the skills needed to produce products and services that non-researchers are willing to buy.
The centerpiece of the program is “customer discovery” in which the teams must talk with at least 100 potential customers about their proposed product. This interaction with the real world almost inevitably leads to what I-Corps calls “the pivot,” which occurs when the teams, based on the customer feedback, realize they’ve been developing a product for which there isn’t a market. In many cases, that realization leads to new, and successful, directions for the technology.
“Everyone starts out with one idea about what they want to do, and they almost always change to something else that they are also capable of doing,” McGreggor said. “It can be difficult for people to switch gears, but what’s beautiful about this program is that they do switch.”
At the end of the six weeks, the teams decide whether or not to go forward with their idea. For Georgia Tech teams, fledgling companies that emerge from the process can join VentureLab, a program that helps researchers form companies, create prototypes, bring in experienced management and obtain early-stage funding. VentureLab companies can go on to be members of the Advanced Technology Development Center (ATDC), Georgia Tech’s accelerator program that helps entrepreneurs launch and build successful companies.
Marketing MOFs
Krista Walton and David Sholl used the I-Corps process to confirm the market need for metal-organic frameworks (MOFs), a new materials technology with a broad range of potential market applications. With NSF support, the researchers had developed a way to scale up the synthesis of MOFs, a class of nanomaterials, but weren’t sure what direction to take next – a classic problem for technologies that have many possible applications.
“By talking with more than 100 potential customers, we went through numerous refinements in our understanding of how we can create a sustainable business with our technology,” said Sholl, who is now chair of Georgia Tech’s School of Chemical and Biomolecular Engineering. “We saw over and over again that the issues that obsess researchers doing fundamental research and the issues that matter to customers are often not the same.”
Talking with the customers required a large investment of time, but Sholl – who is also a Georgia Research Alliance Eminent Scholar in Energy Sustainability – was pleased with the level of interest in the technology. The potential customers he and Walton interviewed also identified applications they had never considered.
As a result of the process, Sholl and Walton – an associate professor in the School of Chemical and Biomolecular Engineering – formed Inmondo Tech, and are working with several initial customers to develop a first product.
Smartphone Questions
For Gregory Abowd, the benefits of I-Corps were different. A serial entrepreneur with a record of launching successful companies, Abowd felt he knew how to commercialize technology he developed that helps connect young patients with their doctors through handheld devices. But he wanted to apply I-Corps’ systematic process to starting up a new company.
“I’ve had some successful and unsuccessful startup efforts, but I really didn’t understand what were the important elements of the successful ones,” said Abowd, who is a Regents’ and Distinguished Professor in Georgia Tech’s School of Interactive Computing. “I was intrigued with the idea of being a little more structured going into this one, because I had learned there are an infinite number of ways to make mistakes in the business world.”
The company, established as L.S.Q. LLC in Georgia, will provide a way to ask questions of smartphone users at times when they aren’t actively using their handheld devices. Building on the original purpose of the technology, which was to boost interaction with children who have chronic diseases, Abowd sees many possible applications, including surveys designed for the small screens of mobile devices.
“We’ll ask questions at a point when people are interacting with their phones, but at a point of pause,” he explained. Abowd has assembled a team and is talking with potential customers. He expects to form a joint venture with a market research firm in early 2014 and develop a product quickly.
Advice to Others
What advice do the teams give faculty members and graduate students thinking about the I-Corps opportunity?
“There is a growing network to help with commercialization, both at Georgia Tech and around the country,” noted Abowd. “A successful startup requires a lot of effort, and it’s more than a full-time job. I-Corps gives you a six-week exposure to help you determine whether this is right for you.”
I-Corps requires a large investment of time, something that can be difficult if faculty members aren’t prepared for it, Howard noted. To be successful, at least one member of the team has to be available nearly full-time during the six-week program.
“I would recommend this 100 percent, and have already talked with other faculty members about I-Corps,” she said. “This process is very different from what we normally do in research and teaching, and it has changed the way I think about what I do. It was a great experience for us.”
I-Corps teams follow a rigorous application process designed to determine whether team members are truly committed to launching and building a startup, McGreggor noted. That can be daunting.
“I-Corps simulates a startup, so it puts a lot of heat on the team to see if they are going to stay together when they get into a company,” he said. “We challenge the researchers in ways that they have probably not been challenged since they were graduate students. It is exquisitely uncomfortable for some people.”
Broader Impacts
I-Corps has also changed the way that Georgia Tech approaches startup companies. Customer discovery and early pivoting to serve the marketplace, for instance, are now at the core of Georgia Tech’s VentureLab and Flashpoint programs, which serve all researchers regardless of their funding sources, McGreggor said.
“Faculty members are forced to look into the face of a world that may not want what they have produced,” McGreggor said. “What we’ve learned is that when entrepreneurs get it wrong, it’s usually because they are building something that nobody really wants. This has really changed our approach to doing things in VentureLab.”
The I-Corps approach has also changed the role of graduate students in the startup process, and opened it more to junior faculty members. In the past, VentureLab had assumed that only tenured faculty would have the time and flexibility to commit to a startup. Now, he says, the program makes no distinction among researchers, and realizes that the graduate students involved in developing a technology may be the right team members to go forward as part of the new company. That makes creating a startup a real alternative to traditional post-graduation opportunities.
Beyond the new enterprises begun, the I-Corps program is having a larger impact on the universities whose faculty members have participated.
“Additional successes of the program have been far-reaching,” said the NSF’s DasGupta. “Faculty are taking what they learned in I-Corps about innovation and technology transfer back to their universities and training their students differently. The participation of students and post-docs in I-Corps has also had favorable impacts: they report that their employability is enhanced by their participating in I-Corps.”
The program was launched in 2011, and continues to evolve as NSF tracks the results. In addition to its teams of researchers, entrepreneurs and mentors, I-Corps is also focusing on nodes and sites to bring the concepts to a larger group of NSF researchers.
“We continue to explore ways to expand the program’s impact nationally, and at the state and local levels,” DasGupta added.
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]]>Glaucoma is a group of diseases that can damage the eye’s optic nerve and cause vision loss and blindness. Elevated eye pressure is the main risk factor for optic nerve damage.
Researchers have implicated a mutant form of a protein called myocilin as a possible root cause of this increased eye pressure. Mutant myocilin is toxic to the cells in the part of the eye that regulates pressure. These genetically inherited mutants of myocilin clump together in the front of the eye, preventing fluid flow out of the eye, which then raises eye pressure. This cascade of events can lead to early onset-glaucoma, which affects several million people from childhood to age 35.
To find molecules that bind to mutant myocilin and block its aggregation, researchers designed a simple, high-throughput assay and then screened a library of compounds. They identified two molecules with potential for future drug development to treat early onset glaucoma.
“These are really the first potential drug targets for glaucoma,” said Raquel Lieberman, an associate professor in the School of Chemistry and Biochemistry at the Georgia Institute of Technology in Atlanta, whose lab led the research.
Lieberman presented her findings on January 20 at the Society for Laboratory Automation and Screening conference in San Diego, Calif.
The study was published on Nov. 26, 2013, in the journal ACS Chemical Biology. The National Institutes of Health and the Pew Scholar in Biomedical Sciences program provided support for the research. The work was a collaboration involving Georgia Tech, Emory University and the University of South Florida.
At the heart of the study was an assay that Lieberman’s lab created to take advantage of the fundamental principles of ligand binding. In their assay, mutant myocilin is mixed with a fluorescent compound that emits more light when the protein is unwound. When a molecule from the library screen binds to myocilin, the pair becomes highly stable – tightly wound – and the fluorescent light emitted decreases. By measuring fluorescence, researchers were able to identify molecules that bound tightly to mutant myocilin.
The researchers then added these molecules to cultured human cells that were making the toxic aggregating myocilin. Treating the cells with the newly identified molecules blocked the aggregation and caused the mutated version of myocilin to be released from the cells, reducing toxicity.
“We found two molecules from that initial screen that bound to our protein and also inhibited the aggregation,” Lieberman said. “When we saw that these compounds inhibited aggregation then we knew we were onto something good because aggregation underlies the pathogenesis of this form of glaucoma.”
In a separate study, Lieberman’s lab characterized the toxic myocilin aggregates. That study was published in December 2013 in the Journal of Molecular Biology. The study found that myocilin aggregates are similar to the protein deposits called amyloid, which are responsible for Alzheimer’s disease and other neurodegenerative diseases.
“In Alzheimer’s disease, the deposits are extracellular and kill neurons. In glaucoma the aggregates are not directly killing neurons in the retina to cause vision loss, but they are cytotoxic in the pressure-regulating region of the eye,” Lieberman said. “It’s parallel to all these other amyloids that are out there in neurodegenerative disease.”
The researchers are now focusing on mapping the structure of myocilin to learn more about what myocilin does and why it is in the eye in the first place.
“The underlying problem with myocilin is that for 14 years it has been studied and still nobody really knows what its biological role is inside the eye,” Lieberman said.
This research is supported by the National Institutes of Health (NIH) under award numbers RO1EY021205 and RO1NS073899, and the Pew Scholar in Biomedical Sciences program. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.
CITATION: Susan D. Orwig, et al., "Ligands for glaucoma-associated myocilin discovered by a generic binding assay," (ACS Chemical Biology, November 2013). (http://dx.doi.org/10.1021/cb4007776).
CITATION: Shannon E. Hill, et al., “The glaucoma-associated olfactomedin domain of myocilin forms polymorphic fibrils that are constrained by partial unfolding and peptide sequence,” (Journal of Molecular Biology, December 2013). (http://dx.doi.org/10.1016/j.jmb.2013.12.002).
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]]>Researchers examining the chemical warfare taking place on Fijian coral reefs have found that one species of seaweed increases its production of noxious anti-coral compounds when placed into contact with reef-building corals. But as it competes chemically with the corals, the seaweed grows more slowly and becomes more attractive to herbivorous fish, which boost their consumption of the skirmishing seaweed by 80 percent.
This appears to be the first demonstration that seaweeds can boost their chemical defenses in response to competition with corals. However, determining whether such responses are common or rare awaits additional studies with a broader range of seaweeds and corals.
The research, sponsored by the National Science Foundation and the National Institutes of Health, was published January 8, 2014, in the journal Proceedings of the Royal Society B.
“The important takeaway is that competition between corals and seaweeds can cause dramatic changes in seaweed physiology, both in terms of their growth and their defense,” said Douglas Rasher, who was a graduate student at the Georgia Institute of Technology when the research was conducted. “These changes have potentially cascading effects throughout the rest of the reef community.”
Rasher, now a postdoctoral research associate at the Darling Marine Center at the University of Maine, conducted the research in collaboration with Mark Hay, a professor in the Georgia Tech School of Biology. Hay and Rasher have used coral reefs as field laboratories, studying the chemical signaling that occurs during coral-seaweed competition, and evaluating how herbivorous fish affect the interactions – and long-term health of reefs.
“We previously found that chemical warfare is fairly common among seaweeds and corals, and that several seaweed species are particularly harmful to corals,” Rasher said. “This research explored the degree to which seaweed allelopathy – chemical warfare – is dynamic, how it changes in response to competition, and also whether competition changes the efficacy of other seaweed defenses used against herbivores.”
The findings may also challenge the popular notion that plants cannot change rapidly and strategically in response to their environments.
“We tend to think of plants as being fixed in their behavior,” said Hay. “In fact, plants such as these seaweeds assess their environment continuously, altering biochemically what they are doing as they compete with the coral. These algae somehow sense what is happening and respond accordingly. They may appear passive, but they are really the tricky chemical assassins of coral reefs.”
For this study, Rasher and Hay selected two seaweed species, one (Galaxaura filamentosa) known for its toxicity to corals, and the other (Sargassum polycystum), which does not chemically damage corals. They fragmented pieces of a common coral, Porites cylindrica, glued them into cement cones and placed them on a rack on a reef located in the shallow ocean off the Fiji Islands. The fragments were allowed to grow in the racks for two years.
At the start of the experiment, the researchers took half of the coral samples and dipped them into bleach to kill the living organisms, leaving only the calcium carbonate skeletons. The skeletons served as the control group for the experiments that followed.
The researchers collected samples from both species of seaweed, and split each sample in two. One half of each sample was assigned to a treatment group, while the other half went to the control group. The treatment group was placed into contact with living corals, while the control group was placed into contact with coral skeletons.
The seaweeds were then allowed to interact with the corals and coral skeletons for eight days. After that, a portion of each sample was removed and chemical compounds extracted from them and embedded into small gel strips that were then adhered to other living corals to assess the toxicity of the compounds. The researchers repeated the experiment, placing entire seaweeds in contact with corals to determine if the plants displayed the same effect.
“We saw that Galaxaura, the chemically rich seaweed and the species we knew was allelopathic, had up-regulated its chemistry to become more potent – nearly twice as damaging – when it was in contact with the living coral, compared to those individuals that had only been in contact with the coral skeletons,” Rasher said.
None of the extracts from the Sargassum damaged the corals.
Until this point, the seaweeds and corals had been protected from herbivorous fishes. The next step was to place seaweed samples – both those that had competed with the living coral and those that hadn’t – onto nylon ropes in a location accessible to fish. The researchers created 15 pairs of these samples and placed them at different reef locations.
“We saw that for the non-allelopathic seaweed, Sargassum, fishes didn’t differentiate – they consumed both the treatment and control seaweeds at equal rates,” Rasher said. “But given the option to choose between treatment and control Galaxaura, fishes consumed 80 percent more of the seaweed portions that had been in contact with a living coral.”
The researchers don’t know all the factors that may have made the chemically noxious seaweed more palatable to the fish. However, those seaweed portions that had been competing with coral had less effective chemical defenses against fish. When the researchers took extracts from treatment seaweed and control seaweed and applied them to a palatable seaweed species not previously used in the experiment, fish preferred the seaweed coated with extracts from the portions that had been competing with corals, indicating that competition had compromised the seaweed’s chemical defenses against herbivores.
For the future, the researchers want to study chemical defenses in other seaweeds to determine if what they’ve seen is common among tropical seaweeds that engage in chemical warfare. For now, they don’t know if the chemical defenses evolved to compete with coral or perhaps for another reason, such as fighting off harmful microbes.
The fact that corals may cause seaweeds to up-regulate their anti-coral defenses could help explain why coral reefs rarely bounce back once they begin a decline and become dominated by seaweeds. The research also demonstrates the importance of studying broad interactions among numerous species within complex communities like coral reefs.
“These kinds of interactions show a mechanism that, once the reef begins to crash, could help maintain that decline,” Hay said. “There may be insights here that we could use to better manage, and hopefully restore, some of these systems. We are also hoping that what we learn may bleed over into other systems.”
This research was supported by the National Science Foundation (NSF) under award (OCE-0929119), by the National Institutes of Health (NIH) under award (U01-TW007401), and by the Teasley Endowment to Georgia Tech. The conclusions or recommendations contained in this news release are those of the authors and do not necessarily represent the official positions of the NSF or NIH.
CITATION: Douglas B. Rasher and Mark E. Hay, “Competition induces allelopathy but suppresses growth and anti-herbivore defense in a chemically rich seaweed,” (Proceedings of the Royal Society B, January 2014). http://dx.doi.org/10.1098/rspb.2013.2615
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]]>Molecular chlorine, from sea salt released by melting sea ice, reacts with sunlight to produce chlorine atoms. These chlorine atoms are highly reactive and can oxidize many constituents of the atmosphere including methane and elemental mercury, as well activate bromine chemistry, which is an even stronger oxidant of elemental mercury. Oxidized mercury is more reactive and can be deposited to the Arctic ecosystem.
The study is the first time that molecular chlorine has been measured in the Arctic, and the first time that scientists have documented such high levels of molecular chlorine in the atmosphere.
“No one expected there to be this level of chlorine in Barrow or in polar regions,” said Greg Huey, a professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology in Atlanta.
The study was published January 12 in the journal Nature Geoscience and was supported by the National Science Foundation (NSF), part of the international multidisciplinary OASIS program.
The researchers directly measured molecular chlorine levels in the Arctic in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. At first the scientists were skeptical of their data, so they spent several years running other experiments to ensure their findings were accurate.
The level of molecular chlorine above Barrow was measured as high as 400 parts per trillion, which is a high concentration considering that chlorine atoms are short –lived in the atmosphere because they are strong oxidants and are highly reactive with other atmospheric chemicals.
Molecular chlorine concentrations peaked in the early morning and late afternoon, and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone may be required for molecular chlorine formation.
Previous Arctic studies have documented high levels of oxidized mercury in Barrow and other polar regions. The major source of elemental mercury in the Arctic regions is coal-burning plants around the world. In the spring in Barrow, ozone and elemental mercury are often depleted from the atmosphere when halogens — chlorine and bromine — are released into the air from melting sea ice.
“Molecular chlorine is so reactive that it’s going to have a very strong influence on atmospheric chemistry,” Huey said.
Chlorine atoms are the dominant oxidant in Barrow, the study found. The area is part of a region with otherwise low levels of oxidants in the atmosphere, due to the lack of water vapor and ozone, which are the major precursors to making oxidants in many urban areas.
In Barrow, snow-covered ice pack extends in every directly except inland. The ultimate source of the molecular chlorine is the sodium chloride in sea salt, Huey said, most likely from the snow-covered ice pack. How the sea salt is transformed into molecular chlorine is unknown.
“We don’t really know the mechanism. It’s a mystery to us right now,” Huey said. “But the sea ice is changing dramatically, so we’re in a time where we have absolutely no predictive power over what’s going to happen to this chemistry. We’re really in the dark about the chlorine.”
Scientists do know that sea ice is rapidly changing, Huey said. The sea ice that lasts from one winter to the next winter is decreasing. This has created a larger area of melted ice, and more ice that comes and goes with the seasons. This seasonal variation in ice could release more molecular chlorine into the atmosphere.
“There is definite climate change happening in the Arctic,” Huey said. “That’s changing the nature of the ice, changing the volume of the ice, changing the surface area and changing the chemistry of the ice.”
This research is supported by the National Science Foundation under award number ATM-0807702, ARC-0806437 and ARC-0732556. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the NSF.
CITATION: Jin Liao, et al., "High levels of molecular chlorine n the Arctic atmosphere," (Nature Geoscience, January 2014). (http://dx.doi.org/10.1038/NGEO2046).
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]]>The trick is to identify when such attacks are underway.
The Department of Energy has awarded the Georgia Tech Research Institute (GTRI) $1.7 million to help detect cyber attacks on our nation’s utility companies.
By partnering with the Georgia Tech School of Electrical and Computer Engineering’s National Electric Energy Testing, Research and Applications Center (NEETRAC) and the Strategic Energy Institute (SEI), GTRI will work together with experts in smart grid technology to develop protocols and tools to detect such attacks.
“Utilities and energy delivery systems are unique in several ways,” said GTRI researcher Seth Walters, one of the principal investigators on the project. “They provide distribution over a large geographic area and are composed of disparate components which must work together as the system’s operating state evolves. Relevant security technologies need to work within the bandwidth limitations of these systems in order to see broad adoption and they need to account for the varying security profiles of the components within these power systems.”
To detect adversarial manipulation of the power grid, the cyber security tool suite will consist of advanced modeling and simulation technologies and a network of advanced security sensors capable of acting to protect the power system in real-time on the basis of this modeling and simulation.
Rather than attempting to identify the source of an attack, the system will evaluate the content of information sent to the power system.
“It is impossible to predict what a clever cyber attacker can devise in the future,” said A.P. “Sakis” Meliopoulos, a Georgia Power Distinguished Professor in the School of Electrical and Computer Engineering (ECE), who is part of the team. “A command to the control and operation infrastructure of the system can be evaluated on the basis of its content and the effect on the power system.”
The system will build on past Georgia Tech research into the monitoring, protection, control and operation of electric power utilities and their automation infrastructure, as well as work on information security. Georgia Tech’s power system control and automation laboratory will be used to develop methods to detect intrusion and malicious commands before the system is field demonstrated in an actual utility environment.
“This project is particularly exciting as it integrates GTRI’s cyber security expertise, with the expertise in grid and electrical power of NEETRAC and ECE,” said SEI Executive Director Tim Lieuwen. “A key piece of our energy strategy is promoting certain signature energy areas where Georgia Tech combines unique breadth and depth into best of class capabilities – the area of electrical power is one of those, and this project further demonstrates Georgia Tech’s commitment to this space.”
The project will consist of three phases, which include research and development, test and validation at Georgia Tech, and technology demonstration at operational utility sites with the assistance of multiple utility company partners.
“GTRI’s expertise in systems engineering and cyber security will be a great advantage for execution on this award,” Walters said. “We also have the singular advantage in being able to collaborate with professors from Georgia Tech. The School of Electrical and Computer Engineering was instrumental in bringing emerging research ideas to the proposal narrative.”
GTRI worked with Meliopoulos, ECE Associate Professor Santiago Grijalva and NEETRAC engineer Carson Day, who are experts in power grid and smart grid technology, and Raheem Beyah, an ECE associate professor and an expert in cyber security.
“My group, the Communications Assurance and Performance [CAP] Group, will work with GTRI researchers to develop, test and deploy a context-aware network-based intrusion detection system [NIDS],” Beyah said. “Working with a power grid simulator, the NIDS will have the ability to prevent network packets containing application-layer commands that render the power grid unstable from entering the network.”
A Georgia Power Distinguished Professor and SEI Associate Director, Grijalva will integrate a cyber-power co-simulator where numerous cyber-attack mechanisms can be simulated, including their effects in the physical power infrastructure. He will also develop real-time decision-making algorithms that evaluate the impact of potential cyber-induced power infrastructure malfunction.
“The proposed cybersecurity system is complex, so a disciplined approach to delivering a system of systems which embodies this complexity will be required,” Walters said. “Furthermore, as part of research and development, we will be working to ensure that the tool suite, as conceptualized by the team, remains relevant to current and emerging industry needs.”
Andrew Howard, who heads GTRI’s research on emerging threats and countermeasures, noted that this is a unique part of this proposal. “This proposal isn’t just about the research,” Howard said. “In addition to the extensive modeling and simulation, it’s also about developing a commercialization plan for other utilities to benefit.”
The research described in this news release is supported by the Department of Energy under contract number DE-OE0000673. Any findings or opinions expressed are those of the authors and do not necessarily represent the official views of the Department of Energy.
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]]>To help answer those questions, researchers, policy-makers and R&D directors study patent maps, which provide a visual representation of where universities, companies and other organizations are protecting intellectual property produced by their research. But finding real trends in these maps can be difficult because categories with large numbers of patents – pharmaceuticals, for instance – are usually treated the same as areas with few patents.
Now, a new patent mapping system that considers how patents cite one another may help researchers better understand the relationships between technologies – and how they may come together to spur disruptive new areas of innovation. The system, which also categorizes patents in a new way, was produced by a team of researchers from three universities and an Atlanta-based producer of data-mining software.
“What we are trying to do is forecast innovation pathways,” said Alan Porter, professor emeritus in the School of Public Policy and the School of Industrial and Systems Engineering at the Georgia Institute of Technology and the project’s principal investigator. “We take data on research and development, such as publications and patents, and we try to elicit some intelligence to help us gain a sense for where things are headed.”
Patent maps for major corporations can show where those firms plan to diversify, or conversely, where their technological weaknesses are. Looking at a nation’s patent map might also suggest areas where R&D should be expanded to support new areas of innovation, or to fill gaps that may hinder economic growth, he said.
Innovation often occurs at the intersection of major technology sectors, noted Jan Youtie, director of policy research services in Georgia Tech’s Enterprise Innovation Institute. Studying the relationships between different areas can help suggest where the innovation is occurring and what technologies are fueling it. Patent maps can also show how certain disciplines evolve.
“You can see where the portfolio is, and how it is changing,” explained Youtie, who is also an adjunct associate professor in the Georgia Tech School of Public Policy. “In the case of nanotechnology, for example, you can see that most of the patents are in materials and physics, though over time the number of patents in the bio-nano area is growing.”
The patent mapping research, which was supported by the National Science Foundation, will be described in a paper to be published in an upcoming issue of the Journal of the American Society for Information Science and Technology (JASIST). In addition to Youtie and Porter, the research was conducted by former Georgia Tech graduate student Luciano Kay, now a postdoctoral scholar at the Center for Nanotechnology in Society at the University of California Santa Barbara.
“The goal for this research was to create a new type of global patent map that was not tied into existing patent classification systems,” Kay said. “We also wanted an approach that would classify patents into categories or clusters in a graphical representation of interrelated technologies even though they may be located in different sections and levels of the standard patent classification.”
The International Patent Classification (IPC) system is based on a hierarchy of eight top-level classes such as “human necessity” and “electricity.” Patent applications are further classified into 600 or so sub-classes beneath the top-level classes.
Critics note that the IPC brings together technologies such as drugs and hats under the “human necessity” class -- technologies that are not really closely related. The system also puts technologies that are closely related – pharmaceuticals and organic chemistry, for instance – into different classes.
The new Patent Overlay Mapping system does away with this hierarchy, and instead considers the similarity between technologies by noting connections between patents – which ones are cited by other patents.
“We completely disaggregated the patient classification system and looked at all the categories with at least a thousand patents,” Youtie explained. “We think our map gets closer to measuring the ideas of technological similarity and distance.”
Maps produced by the system provide visual information relating the distances between technologies. The maps can also highlight the density of patenting activity, showing where investments are being made. And they can show gaps where future R&D investments may be needed to provide connections between related technologies.
The researchers produced a series of patent maps by applying their new system to 760,000 patent records filed in the European Patent Office between 2000 and 2006. The data came from the PatStat database, and was analyzed using a variety of tools, including the VantagePoint software developed by Search Technology of Norcross, along with Georgia Tech and Intelligent Information Services Corporation.
One surprise in the work was the interdisciplinary nature of many of the 35 patent factors the researchers identified. For instance, the classification “vehicles” included six of the eight sections defined by the IPC system. Only five of the 35 factors were confined to a single section, Youtie said.
Because the researchers adopted a new classification system, other researchers wanting to follow their approach will have use a thesaurus that translates existing IPC classes to the new system. That conversion system is available online.
In addition to those already mentioned, the research team also included Ismael Rafols of Universitat Politecnica de Valencia in Spain and Nils Newman of Intelligent Information Services Corp.
This research was supported by the National Science Foundation (NSF) through the Center for Nanotechnology in Society at Arizona State University (Award No. 0531194) and NSF Award No. 1064146. The research was also undertaken in collaboration with the Center for Nanotechnology in Society, University of California Santa Barbara (NSF Awards No. 0938099 and No. 0531184). The findings and observations contained in this paper are those of the authors and do not necessarily reflect the views of the NSF.
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]]>The C-MAX Solar Energi Concept is a first-of-its-kind hybrid electric vehicle with the potential to free drivers of their dependence on the electric grid. Instead of recharging its battery from an electrical outlet, C-MAX Solar Energi Concept harnesses the power of the sun by parking under a special concentrator that acts like a magnifying glass, directing intensified rays from the sun onto solar panels on the parked vehicle’s roof below.
The result is a car that takes a day’s worth of sunlight to deliver the same performance as Ford’s conventional C-MAX Energi plug-in hybrid, which gets combined miles per gallon gasoline equivalent (MPGe), with EPA-estimated 108 city/92 highway/100 combined MPGe.
“Ford didn’t just want to build an electric car, but a plug-in hybrid electric car that actually uses green electricity,” said Bert Bras, a professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology in Atlanta. “Just putting photovoltaic cells onto a car is not going to do it, so they reached out to us to help progress the concentrator idea.”
The car is continuing its media tour this week at the North American International Auto Show in Detroit. The concept car is a Ford-led collaborative project with Georgia Tech and San Jose, Calif.-based SunPower Corp.
Ford and SunPower co-developed the solar panel-based roof specifically for C-MAX Solar Energi Concept. Because of the time that would be needed for conventional solar panels to absorb enough energy to fully charge the vehicle, Ford turned to Prof. Bras’ Sustainable Design and Manufacturing lab at Georgia Tech for ways to amplify the sun light to make a solar-powered hybrid feasible for daily use.
His lab helped develop a car port type solar concentrator that uses lenses similar to what lighthouses use to amplify a small light. Special Fresnel lenses in the car-port direct sunlight to the solar panels on the vehicle’s roof, so the concentrator acts “like a magnifying glass, but it’s squished,” Bras said. Grooves in the thin glass reflect the sunlight down to the car, boosting sunlight’s impact by a factor of eight.
The patent-pending system tracks the sun as it moves from east to west, drawing enough power from the sun daily to equal an 8 kilowatt hour battery charge. The car's self-parking features can automatically move the car to keep the sunlight focused on the rooftop panels. Bras’s lab modeled the size and dimensions of the concentrator needed to get to 8 kWh per day. That charge is possible in the concept car, but much work remains before this off-the-grid car can hit the streets.
“There is more work to do, but the basic principle, can you charge a car with 8 kilowatt hours per day using pure sunlight? Yes, you can,” Bras said. “The next step will be to test it in practical situations.”
By using renewable power, Ford estimates that the C-MAX Solar Energi Concept will reduce the annual greenhouse gas emissions (GHG) from a typical car owner by four metric tons.
Internal Ford data suggests the sun could power up to 75 percent of all trips made by an average driver in a solar hybrid vehicle. This could be especially important in places where the electric grid is underdeveloped, unreliable, expensive and dirty.
“We like to do these concepts that push the boundaries, like Ford does also,” Bras said. “They want to boost sustainability and get off of the electricity power grid. That’s what we’re really after.”
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]]>Scientists studying grasslands in Oklahoma have discovered that an increase of 2 degrees Celsius in the air temperature above the soil creates significant changes to the microbial ecosystem underground. Compared to a control group with no warming, plants in the warmer plots grew faster and higher, which put more carbon into the soil as the plants senesce. The microbial ecosystem responded by altering its DNA to enhance the ability to handle the excess carbon.
“What we conclude from this study is the warming has an effect on the soil ecosystem,” said Kostas Konstantinidis, an assistant professor who holds the Carlton S. Wilder Chair in Environmental Engineering at the Georgia Institute of Technology. “It does appear that the microbes change genetically to take advantage of the opportunity given to them.”
The study was published online Dec. 27, 2013, in the journal Applied and Environmental Microbiology. The research was sponsored by the Department of Energy, and involved collaboration with several universities, including the University of Oklahoma.
The findings are the culmination of a 10-year study that seeks to understand how the most intricate ecosystem in nature — soil — will respond to climate change.
A single gram of soil is home to a billion bacterial cells, representing at least 4,000 different species. In comparison, the human gut is home to at least 10 times fewer different species of bacteria. Scientists have little idea what microbes in the soil do, how they do it, or how they respond to changes in their environment, Konstantinidis said. This limits the predictive capabilities of climate models.
“In models of climate change it is a black box what happens to the carbon in soil,” Konstantinidis said. “One reasons that models of climate change have such big room for variation is because we don’t understand the microbial activities that control carbon in the soil.”
Complicating matters, 99.9 percent of the microbes in the soil cannot be grown in the lab, so scientists must study them where they live. The molecular and genomic techniques to do so are a specialty of the Konstantinidis lab. (More on the Konstantinidis lab)
The researchers traveled to the Kessler Farm Field Laboratory in McClain County, Oklahoma, where they conducted their study on grassland soils, which had been abandoned for agriculture use for more than 20 years. The scientists warmed plots of soil with radiators set a few feet above the ground for 10 consecutive years. They warmed these plots 2 degrees Celsius, which many climate models forecast as the global temperature increase over the next 50 years.
The researchers took samples of the plants, measured the carbon content and the number of microbes in the soil, and documented any changes in the warm plots versus the control plots. The team also extracted DNA from the soil and identified the genetic composition and changes of the microbes living there.
The plants in the warm plots grew better and higher. As the plants started senescing at theend of the season, their higher biomass led to more carbon in the soil. However, the microbial communities had increased their rate of respiration, which converted soil organic carbon to carbon dioxide (CO2), so the total carbon in the warm and control soils was similar.
The microbial communities in the warm soils had undergone significant changes during the decade of the experiment, which facilitated their higher respiration rate. For instance, the study of the DNA of the microbes revealed found that the microbial communities of the warm plots had more genes related to carbon respiration than the microbes in the control plots.
“That was consistent with the idea that the additional carbon from the plants was all respired and converted to CO2,” Konstantinidis said. “We saw that the warmed microbial community was more efficient in eating up the plant-derived soil carbon and making it CO2.”
The research team plans to do similar studies in other agricultural soils and in colder areas, such as Alaska tundra permafrost ecosystems, where there is more organic carbon in the soil.
“There are complex interactions between plants and microbes and we need to understand them better to have a more predictive understanding of what’s going on,” Konstantinidis said. “This is the first study trying to do that, but we are not close to the complete understanding yet.”
This research is supported by the Department of Energy under award number DE-SC0004601.Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the DOE.
CITATION: Chengwei Luo, et al., "Soil microbial community responses to a decade of warming as revealed by comparative metagenomics," (Applied and Environmental Microbiology, January 2013). (http://dx.doi.org/10.1128/AEM.03712-13).
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A $2.9 million cooperative agreement with the Georgia Institute of Technology will advance that goal by developing information that military resource planners can use to optimize energy consumption depending on mission needs and local conditions. By developing, evaluating and integrating dynamic modeling and simulation tools for this task, the researchers will help the DoD meet energy needs while reducing liquid fuel consumption and logistics support.
The four-year project is part of the Consortium for Optimally Resource-Secure Outposts (CORSO), a first-of-its-kind research consortium involving academia, industry and government laboratories.
“Our role is to develop physics-based simulation approaches for a number of promising technologies that support heating, ventilation and air conditioning needs at these forward operating bases,” said Yogendra Joshi, a professor in Georgia Tech’s George W. Woodruff School of Mechanical Engineering and the project’s principal investigator. “These applications are the largest non-propulsion consumers of liquid fuels, though we will also look at other uses of energy.”
Supported by the DoD’s Operational Energy Capabilities Improvement Fund through the Office of Naval Research (ONR), the project will also involve researchers at the National Renewable Energy Laboratory (NREL), Oak Ridge National Laboratory (ORNL), DoD laboratories, and a number of companies that are producing energy-related technologies. The consortium won’t be developing new hardware, but will instead focus on how best to integrate existing technologies – including renewables where they meet other mission criteria.
“Better energy options make our forces more flexible and adaptive in combat,” said Sharon E. Burke, Assistant Secretary of Defense for Operational Energy Plans and Programs. “Tapping academia and the national labs will give us access to a greater range of expertise in this dynamic area.”
Forward operating bases are typically located in remote areas far from reliable power grids. To carry out military missions and support the personnel there, U.S. Marines in Afghanistan consume 200,000 gallons of fuel per day, Sea Power Magazine recently reported. Air conditioning in the summer months can consume as much as 60 percent of a base’s fuel.
The consortium will focus a broad range of expertise on addressing these energy needs.
“This is a unique collaboration between the Department of Defense and the Georgia Institute of Technology to develop modeling approaches to enhance the operational effectiveness and resource security of expeditionary outposts by reducing battlefield fuel consumption,” said Mark S. Spector, program officer in the Ship Systems and Engineering Division of the Office of Naval Research (ONR). “A key aspect of the Georgia Tech consortium will be their engagement with innovators who have not previously worked directly with the government. This effort is a critical piece of a larger effort led by the Office of Naval Research in partnership with the Department of Energy’s Office of Energy Efficiency & Renewable Energy to determine the optimal balance of energy resources in an operational environment.”
Beyond heating, ventilation and air-conditioning, the bases typically need power for weapons systems. Those systems often require large amounts of energy for short periods of time, while the HVAC needs are more consistent over time. Fresh water production and waste disposal also require energy.
In optimizing the energy use, the researchers will have to take into account unique aspects of the forward operating bases. Wind turbines, for example, might be attractive from an energy perspective in certain locations, but could attract unwanted attention. Highly efficient HVAC systems use less energy, but might be more difficult to transport because of their weight.
“The key issue is that these bases are off-grid, so you have to be able to store energy and supply it when needed,” Joshi noted. “There is a lot of good work going on in terms of technologies that are already in the commercial world that might be useful in these unique conditions.”
At Georgia Tech, the research team will include four faculty members from the College of Engineering. In addition to Joshi, who specializes in energy efficiency, they include:
Among the technologies that will be studied are ground-coupled heat pumps. These devices take advantage of relatively constant subsurface temperatures to provide heating and cooling. Because they take advantage of natural differences between surface and subsurface conditions, they can be more efficient than the liquid-fueled HVAC systems the military has used.
The team will also examine renewables, such as solar, and how they could be integrated with other energy sources. Information about these energy sources will be integrated into large-scale system models already developed by NREL, Joshi said.
Beyond academic and national lab resources, the consortium will identify and collaborate with companies that are developing energy technologies that may help the DoD reach its goals. In particular, the consortium is seeking innovative ideas from small businesses and non-traditional defense contractors.
“We will find companies that have really compelling technologies for these outposts and we will then be able to provide test data on their technologies,” Joshi explained. “The companies will also help with validating the models we develop.”
The project will also include an educational component to share energy optimization information with DoD planners and engineers through curriculum being developed by the Naval Postgraduate School. Technology transfer could also use short-term MOOCs, which would reduce the need for DoD personnel to travel to centralized classes.
While the primary goal will be improved support for military bases, the project could also benefit large-scale humanitarian relief missions, which also must operate without grid electricity. Ultimately, reducing the energy required to operate remote bases could impact the way future missions are carried out.
“Optimizing energy consumption in these forward bases is an issue that could have major impacts going forward,” Joshi said. “The mix of technologies that could be useful will shift and the overall approaches will shift. That’s the kind of exciting research and development framework that we intend to bring to bear on this challenge.”
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