Dr. Arul Jayaraman

Understanding how certain pathogenic bacteria strains such as E. coli cause infection in people begins with unraveling the complex “talk” between the trillions of cells living in the human gastrointestinal (GI) tract, says Arul Jayaraman, a Texas A&M University researcher who has developed an artificial system that mimics the unique bacteria-laden environment of the human GI tract.

The system is detailed this month in Lab on a Chip, a scientific journal published by the Royal Society of Chemistry, the largest organization in Europe for advancing the chemical sciences.

It represents a significant step in understanding bacterial interactions in the GI tract because it accurately simulates conditions within that area by enabling human epithelial cells to grow in balance with the naturally occurring bacteria (termed “commensal”) that reside in the GI tract.

Traditionally, growing both types of these cells simultaneously in a laboratory environment has been difficult because bacteria reproduce at a much faster rate than epithelial cells and tend to monopolize the nutrients needed by the epithelial cells, says Jayaraman, assistant professor in the Artie McFerrin Department of Chemical Engineering at Texas A&M University.

“If you try to achieve this in a cell-culture dish what happens is that you have a very nutrient-rich environment that bacteria basically thrive in, dividing rapidly,” Jayaraman says. “You can start with the same number of cells, relatively in proportion, but the bacteria will keep dividing, taking up all of the nutrients. Epithelial cells then do not get what they need. They are typically more finicky than bacterial cells. The numbers then kick in, and it is an exponential process where you will soon have millions of bacteria outnumbering epithelial cells, which will soon die.”

That doesn’t happen in Jayaraman’s model, which grows the epithelial and commensal cell colonies separately before allowing them to interact as they would in the gut. Once the two types of cells are interacting in the right balance, Jayaraman can recreate the sequence of events in a GI tract infection by introducing a foreign pathogen — in this case, enterohemorrhagic E. coli — to the cells within his model.

Previous studies have just added pathogenic bacteria into colonies of endothelial cells, but this approach does not replicate the cellular interactions and chemical signals present in the human GI tract, says Jayaraman, who holds the Ray Nesbitt Professorship at Texas A&M.

“If you really want to understand how the commensal bacteria that are in the GI tract either prevent or enhance infection, you need to have a way in which you can actually recreate the system with both components present – the commensal cells and the epithelial cells,” Jayaraman says. “To our knowledge, this is the first report describing co-culture of bacteria and epithelial cells and its application to investigate pathogen colonization and infection.”

Commensal bacteria, he explains, produce a wide range of bacterial signals, and the concentration of these signals in the GI tract is extremely high.

These signals, he adds, are given off during normal metabolic processes of the cells. While there is no evidence to suggest that they were created specifically for defensive purposes, some of these signals have evolved to act as a line of defense. Others may actually enhance a pathogen’s infectious potential, he says. For the invading pathogen, it’s a matter of “talking” to the right cells and avoiding the “wrong” ones.

It’s a game of “push and pull” that is further complicated by the fact that the strength of these signal levels varies, Jayaraman says. For example, a person may be under a lot of stress, which can cause stress hormones to be high and might in turn diminish the signals that aid in defense against a pathogen. Other times, a gastric disease might kill some of these cells that are emitting a protective signal, lowering the overall strength of the signal and making a person more susceptible to serious infection, Jayaraman notes.

So far, Jayaraman’s model has yielded some interesting findings, shedding light on the constant array of signals being emitted within the GI tract and their effects on invading pathogens. One of those findings reveals how indole, a chemical produced by commensal cells within the GI tract, acts a signal to foreign pathogens.

“Indole already has been shown as an important signal for communication between bacteria,” Jayaraman says. “We are looking at how pathogens might also be affected by indole, and we are seeing that they are indeed affected.”

Specifically, if a pathogen passes through bacteria that produce indole, the pathogen will become less infectious, Jayaraman explains. Conversely, if it passes through bacteria where there is no indole, the pathogen retains it same degree of virulence.

“In a sense, the pathogen is looking for weak points in a ‘wall’ of defense,” Jayaraman says. “We believe this can be applied to several other signals. There might be signals that increase a pathogen’s infectiousness. Does it choose a location in the wall where it can pass through without decreasing its infectious potential, or does it look for a place where its infectiousness is enhanced?”

Contact: Arul Jayaraman, (979) 845-3306, arulj@tamu.edu

Written by Ryan A. Garcia, (979) 845-9237, ryan.garcia99@tamu.edu

Popularity: unranked [?]

A probe developed by members of the Department of Aerospace Engineering’s Aero-Fluids Group, in collaboration with Aeroprobe Corp., was installed in the tip of NASA’s ARES I-X test rocket.

In photos available at http://friendfeed.com/spaceastro/1b5b5a02/ares-i-x-cord-is-loose-from-5-hole-probe-launch-now, the left top picture shows the probe at the tip of the rocket.

NASA’s Ares I-X test rocket lifted off Oct. 28, at 11:30 a.m. EDT from Kennedy Space Center in Florida for a two-minute–powered flight. The flight test lasted about six minutes from its launch from the newly modified Launch Complex 39B until splashdown of the rocket’s booster stage nearly 150 miles downrange.

Courtesy of http://www.nasa.gov/mission_pages/constellation/ares/flighttests/aresIx/index.html

Popularity: unranked [?]

Dr. Shankar Bhattacharyya, professor in the Department of Electrical and Computer Engineering at Texas A&M University, will visit the City University of Hong Kong in December to deliver three lectures, “Advances in Three Term Control” in the City University’s Distinguished Lecture Series.

Dr. Shankar Bhattacharyya

The lectures cover results obtained by him and his coworkers in the field of control engineering. In October 2009 Bhattacharyya will also visit Stanford University, Santa Clara University and the University of California, Berkeley, to give lectures on the same topic. During this visit Bhattacharyya, who is also a concert artist, will give two concerts of Indian Classical Music on the Sarode in Berkeley and Stanford respectively.

Bhattacharyya, the Robert M. Kennedy Professor, joined the Texas A&M electrical and computer engineering faculty in 1980. Prior to this he was professor and head of the electrical engineering department at the Federal University in Rio de Janeiro, Brazil. His honors include being chosen as a NASA Research Fellow in 1974 and a Fellow of the Institute of Electrical and Electronics Engineers (IEEE) in 1989. Bhattacharyya won a Fulbright Lecturing Award in 1989, was chosen as a TEES Fellow in 1989 and TEES Senior Fellow in 2000, a Halliburton Professor in 1991 and won a Boeing “A.D. Welliver” Faculty Fellowship from Boeing Corporation in 1998. He has given invited lectures and short courses in the United States, Italy, Japan, Korea, Brazil, Germany, India and Mexico.

Bhattacharyya’s research focus is control theory, a field in which he has solved several fundamental synthesis and design problems, published six books and more than 200 papers. His current research is directed at developing new approaches for Computer Aided Control System Design (CACSD) for multivariable systems that will enable advanced control theory to be applied to real world systems.

http://www.ece.tamu.edu/NewsAndEvents/Newsletter/Vol11No1/news_bhattacharyya.html

Written by Deana Totzke, deana@ece.tamu.edu

Popularity: unranked [?]

The Texas Engineering Experiment Station (TEES), the research agency of Texas A&M Engineering, and Vestas Wind Systems A/S, the world’s leading supplier of wind power solutions, have signed a Memorandum of Understanding (MOU) to develop a world-class partnership for research in wind energy.

Dr. Theresa Maldonado, associate dean for strategic initiatives and director of the Energy Engineering Institute, shakes hands with Wally Lafferty, vice president and managing director, Vestas Technology R&D Americas following the signing of the Memorandum of Understanding.

The announcement of the MOU was made during a ceremony Friday (Oct. 9) when members of Vestas’ leadership visited Texas A&M and the Department of Aerospace Engineering.

The MOU is the latest step in expanding the engineering program’s capabilities in wind energy research and development, which will help propel Texas toward energy independence. For the past two years, Texas has been the top wind producer in the United States, with more than 3,953 wind-generated megawatts installed. Texas is also the first state to achieve the milestone of one gigawatt of wind installation in a single year (2007).

“Today we are sealing a world-class partnership for research in wind energy using the Vestas and TEES Partnership Collaboration Plan as our framework,” said Dr. Theresa Maldonado, associate dean for strategic initiatives and director of the Energy Engineering Institute. “As we all know, Texas will experience rapid growth in wind power over the next five years, and we are positioned to support that growth.”

TEES and Vestas previously entered into a multiyear master research agreement in June 2008 to collaborate to develop advanced wind energy technologies.

Vestas chose Texas A&M’s System Engineering Program as one of its major university partners for its new R&D center in the United States, while they selected Houston as their U.S.-based R&D headquarters.

Under the new agreement, TEES will provide academic excellence to Vestas research programs in the wind engineering field as well as make a commitment to provide academic programs that will develop Texas A&M University undergraduates and graduates into wind turbine specialists.

Vestas, meanwhile, will sponsor a director for the Wind Center of Excellence for a minimum of three years, execute internal research projects with Texas A&M staff and facilities and contribute associated funds as applicable, provide steering and technical expertise toward the development of the Wind Center of Excellence and associated curriculum and academic programs, and support TEES in bidding for external funding opportunities.

“We are committed to supporting Vestas through the objectives that are outlined in this agreement,” said Maldonado. “We are excited about the new Wind Center of Excellence. We will work aggressively to recruit an excellent director and we are also committed to working with Vestas’ technical staff to develop a new wind energy academic program.”

Written by Tim Schnettler

Popularity: unranked [?]

The Department of Electrical and Computer Engineering at Texas A&M University sponsored the university’s inaugural Nano/Micro Poster Symposium to promote multidisciplinary interaction and scientific communication among students and faculty in the field of nano/micro technology.

The Department of Electrical and Computer Engineering sponsored the inaugural Nano/Micro Poster Symposium.

The symposium started with an invited talk, “Three Dimensions of Individualized Nanomedicine,” from Dr. Mauro Ferrari, a world-renowned expert in nanomedicine. He is currently a professor and chairman of the Department of Nanomedicine and Biomedical Engineering and a professor of internal medicine, at the University of Texas Health Science Center in Houston, as well as a professor of bioengineering at Rice University and president of the Alliance for NanoHealth in Houston. This also was the inaugural talk for the newly launched monthly Texas A&M Nano/Micro Seminar Series.

Following Ferrari’s talk was a poster session, which included more than 65 posters from various disciplines, with more than 150 people from 16 departments across campus participating.

The steering committee was lead by Dr. Arum Han, assistant professor in the electrical and computer engineering department. Other committee members included: Dr. Arul Jayaraman, chemical engineering; Dr. Mike McShane, biomedical engineering; Dr. Dong Hee Son, chemistry; Dr. Winfried Teizer, physics; and Dr. Choongho Yu, mechanical engineering.

Written by Deana Totzke, deana@ece.tamu.edu

Popularity: unranked [?]

Dr. Natarajan Gautam

Associate Professor Natarajan Gautam and Assistant Professor Lewis Ntaimo, faculty members in the Department of Industrial and Systems Engineering, have been awarded a two-year, $240,000 grant by the National Science Foundation (NSF) Service Enterprise Systems program for their project “EAGER: Reducing Energy Consumption in Data Centers.”

This grant provides funding to develop models and methodologies for reducing energy consumption in data centers to the maximum extent possible without degrading the quality of service.

Dr. Lewis Ntaimo

The two researchers will integrate stochastic optimization and stochastic optimal control algorithms to determine: a) the optimal set of meta-applications for virtualization in multiple servers; b) the optimal strategy to control server speeds by dynamic voltage scaling; c) optimal rules for real time cluster sizing.

The algorithms will be developed and integrated under a unified multitime scale platform to exploit their benefits. These methodologies will be used to combine pro-active planning with real time control to reduce energy consumption, operating costs and greenhouse gas emissions from data centers.

Submitted by Katherine Edwards, kedwards@tamu.edu

Popularity: unranked [?]

Dr. Lewis Ntaimo

Dr. Lewis Ntaimo, assistant professor in the Department of Industrial and Systems Engineering at Texas A&M University, and research collaborators at Georgia State University, University of Oklahoma and Oak Ridge National Laboratory have been awarded a $1,000,000 four-year grant by the National Science Foundation’s Cyber-enabled Discovery and Innovation (CDI) program for their project “Collaborative Research: CDI-Type II — Integrated Weather and Wildfire Simulation and Optimization for Wildfire Management.”

Wildfires cause great destruction including the loss of life and damage to property, infrastructure and the environment. The complexity of wildfire management arises from the uncertain dynamic interactions and dependencies among multiple system components. These include highly dynamic and nonlinear wildfire behaviors, weather conditions, and firefighting resource management.

In previous research, these components have been largely treated in isolation in their own fields. To achieve effective wildfire management, decision-making support tools that integrate all these components as a whole are needed. The objective of this project is to develop new models and computation methods that integrate weather prediction, wildfire simulation, data assimilation and stochastic optimization for effective wildfire response management.

The project makes two key paradigm-shifting advances in wildfire modeling and management: 1) coupled weather and wildfire modeling and data assimilation for two-way interactive dynamic weather-wildfire prediction, and 2) Integrated wildfire simulation and stochastic optimization for wildfire containment. The project focuses on computational thinking for understanding the complexity in the natural systems of weather and wildfire behavior, and in the man-made system of firefighting resources management.

Due to the stochastic and multiscale nature of the problem data associated with these systems, the project also involves data assimilation and parallel/distributed computational methods for robust weather and wildfire behavior predictions.

Collaborating with Ntaimo on this project are Dr. Xiaolin Hu from Georgia State University (lead), Dr. Ming Xue and Dr. Yang Hong from the University of Oklahoma, and Dr. James Nutaro of Oak Ridge National Laboratory.

Ntaimo’s portion of the research project will be conducted through the Texas Engineering Experiment Station (TEES) with a funding of $220,000. Ntaimo will collaborate with the Texas Forest Service in College Station to develop new decision models for wildfire emergency response planning.

TEES is the engineering research agency of the State of Texas and a member of The Texas A&M University System.

Popularity: unranked [?]

An old man walks down the stairs in his home. Suddenly, he trips and falls. No one is home to help him. But soon he hears the reassuring clanging of approaching sirens. The surveillance system installed in his home worked: It alerted emergency services, and now, help is on the way.

Dr. Deepa Kundur

Surveillance systems that monitor an environment can be quite useful and are becoming increasingly common. Arrays of strategically placed cameras and sensors can monitor an area and convey information to a node or “sink.” These systems, called distributed multimedia sensor networks (DMSNs), are being used in homes with older people, hospitals and geriatric facilities to monitor activities, spot gait irregularities, and signal that someone has collapsed.

These systems could also be useful in warzones. Once deployed, these networks could transmit important information about enemy location and activities, which could help military personnel strategize better.

But engineering complex surveillance systems that smarten up the environment is tricky. There are security, efficiency and privacy issues to consider. Tackling these issues is Dr. Deepa Kundur, an associate professor at Texas A&M’s Department of Electrical and Computer Engineering. She is analyzing lightweight algorithms that could help improve DMSNs.

Kundur said that directional communications using free space optics is one technology currently being considered for advanced surveillance because of its high data capacity suitable for real-time video communications. One major problem facing directional communications for DMSNs is ensuring connectivity of such networks.

“The sensors use lasers to ‘talk’ with each other,” Kundur said. “To get the message across clearly, they need to be lined up correctly, which can be a housekeeping challenge. Think of a television remote. If you use it to change channels from the wrong angle, it doesn’t work.”

Another hurdle is keeping the network powered. The sensors handle large amounts of data, which can include visual and audio components. Communicating such complex data requires a lot of power, making it necessary to keep the sensors plugged in. This, in turn, leads to mounds of wires cluttering up the environment. The challenge lies in developing sensors that communicate wirelessly, without dropping messages and ensuring that the battery life is sufficiently long.

Ensuring privacy is another concern.

“We don’t want these systems to just gather data. We need them to gather it and then selectively transmit only the relevant parts. If someone falls down, emergency services do not need to know what the person was wearing when he or she fell. The angle of the fall and the person’s fallen position are more important,” Kundur said.

By transmitting only relevant information, the volume of data being communicated is reduced, thereby speeding up transmission.

Protecting DMSNs from attacks is another focus of her research. The lightweight algorithms she studies are also useful in this aspect of security. Kundur measures the probability with which these algorithms can detect attacks and distinguish them from false alarms.

Kundur said she hopes that understanding the limits and suitability of lightweight algorithms will help provide a framework for enhancing their performance with sensors.

“Security translates into safety, but efficiency is important too” Kundur said. “Achieving that crucial balance between security and efficiency is what will help improve DSMNs.”

Written by Marissa Doshi

Popularity: unranked [?]

Taylor Sugg, an undergraduate student in the Artie McFerrin Department of Chemical Engineering at Texas A&M University, has been awarded first place in the Undergraduate Summer Research Grants (USRG) poster competition for his entry, “Constructing a Thermally Stable Hepatitis C Population through a Synthetic Evolution Approach.”

Sugg, a resident of College Station, participated in the competition as part of the Department of Chemical Engineering Research Experience for Undergraduates (REU) program, a National Science Foundation-sponsored initiative that offers undergraduate students from Texas A&M as well as other colleges and universities the opportunity to participate in ongoing research with faculty members during a 10-week period in the summer.

Each summer, chemical engineering-REU students participate in the final USRG poster session, competing with students from other programs throughout the Dwight Look College of Engineering. Sugg, who is supervised by Assistant Professor Zhilei Chen, received top honors for his submission.

USRG is a summer undergraduate research program organized by the Dwight Look College of Engineering at Texas A&M.

Written by Ryan Garcia, ryan.garcia99@tamu.edu

Popularity: unranked [?]

Dr. Jaime Grunlan, right, with Dasarayong Kim, a master's student in Dr. Choongho Yu's research group.

Dr. Choongho Yu and Dr. Jaime Grunlan, assistant professors in the Department of Mechanical Engineering at Texas A&M University, have begun a four-year, $662,897 program with the Air Force Office of Scientific Research to develop polymer composites that can convert heat into electricity.

The project, “Energy Harvesting: Thermoelectric Waste Heat Recovery Using Polymer Nanocomposites,” is part of a larger Air Force initiative to explore the use of alternative energy sources.

The materials Yu and Grunlan are developing will be capable of converting waste heat (such as heat from jet exhaust and body heat) into useful electricity.

Dr. Choongho Yu

“The human body alone could potentially produce enough heat through normal everyday motions to power a cell phone if someone was wearing a shirt made of our thermoelectric composite,” Grunlan said.

Dr. Jaime Grunlan

Of particular interest is the use of these devices in military operations. Small, portable thermoelectric devices could supply power to sensors for detecting chemical or biological weapons, or to cell phones used by soldiers in the field. The thermoelectric devices can be attached to military uniforms to utilize body heat for power generation. And as the devices can also be used for heating or cooling, thermoelectric-equipped uniforms could maintain a comfortable temperature in severe environments.

“All currently used thermoelectrics are semiconductors, so our development of polymer-based materials is novel,” Grunlan said. “State-of-the-art thermoelectric materials are based on bismuth telluride, which is relatively toxic and contains some of the rarest elements on earth. So the ability to make polymer thermoelectrics would transform our ability to convert waste heat into electricity that could be used to power cell phones, electronic switches, etc.”

Submitted by Dr. Jaime Grunlan, jgrunlan@tamu.edu

Popularity: unranked [?]