By Christen L Bailey

New Research Could Help Trace Source of Bioterror Agents

November 6th, 2012 in BME News

By Mark Dwortzan

A bacterial cell receives several inputs from its environment, including the availability of different nutrients and the ambient temperature and pH. Based on these inputs, a bacterium controls its growth rate and molecular composition, which can be thought of as the output of the system. By combining experimental measurements and mathematical models, Paschalidis and Segre aim to gradually dcode this input-output relationship and thereby predict the output given the input or vice versa, enabling researchers to track the source of potential pathogens.

A bacterial cell receives several inputs from its environment, including the availability of different nutrients and the ambient temperature and pH. Based on these inputs, a bacterium controls its growth rate and molecular composition, which can be thought of as the output of the system. By combining experimental measurements and mathematical models, Paschalidis and Segre aim to gradually dcode this input-output relationship and thereby predict the output given the input or vice versa, enabling researchers to track the source of potential pathogens.

Through genetic manipulation or growth in the laboratory, microbes can be engineered for either harmful aims, such as anonymous anthrax attacks, or beneficial purposes, such as vaccines, fuel cells or pollution control systems. A better understanding of how the conditions in which a bacterial cell is grown impact its metabolism and biochemical composition could lead to new tools to help counter potential bioterror threats and advance the development of a wide range of peaceful applications.

Now an interdisciplinary team of systems engineers, computer scientists, microbiologists and biochemists—including Boston University researchers (Professor Yannis Paschalidis (ECE, SE) and Associate Professor Daniel Segrè (Biology, BME, Bioinformatics), as well as the University of Texas and Harvard University—seeks to establish clear links between bacterial cells’ growth conditions and their resulting composition by developing and testing advanced mathematical methods. Funded by a $7.5 million grant from the U.S. Army Research Office, the five-year project could lead to new ways to track the source of a bacterial pathogen, and to help discriminate between natural infectious outbreaks and the deliberate spread of pathogens.

Bacterial cells are typically grown in a nutrient-rich broth containing all the raw materials they need to grow and multiply. The growth medium and environmental factors particular to a lab, such as temperature or pH, constitute the growth conditions that collectively influence the metabolism and biochemical composition of a microorganism. To draw links between a bacterial cell’s growth conditions and its current composition, the researchers plan to model the cell as a system with inputs (growth conditions) and outputs (cell composition), and devise a functional mapping, or mathematical formulas, that transform inputs to outputs and vice versa.

Paschalidis plans to apply optimization techniques to produce these mappings.

“If we observe the cell composition, what can we say about the environment and growth factors impacting that composition?” he says. “The challenge in identifying the source of a bioterror attack is to solve this problem and infer the input from the output.”

Segrè, an expert in the use of mathematical models to drive biological discovery, will develop computer simulations of microbial metabolism and growth under a wide range of possible laboratory conditions. Based on these simulations and experimental measurements to validate their accuracy, Paschalidis will infer how various growth conditions impact the composition of a bacterial cell.

“The composition of the microbial cell may carry information on where it grew and how it evolved, like a hidden signature, that we will try to characterize and interpret,” Segrè observed. “If a bacterium grew under unusual circumstances, or was artificially evolved in a lab, this will likely be reflected in the cell composition.”

Four Young Scholars Named Peter Paul Professors

September 20th, 2012 in BME News

Cited for Cutting-Edge Research

By Rich Barlow

Cara Stepp, a 2012 Peter Paul Professorship recipient, in her Sargent College lab, with Alan Pacheco (ENG’12). Photo by Cydney Scott

Cara Stepp, a 2012 Peter Paul Professorship recipient, in her Sargent College lab, with Alan Pacheco (ENG’12). Photo by Cydney Scott

The simple act of swallowing is a herculean challenge for an estimated one-third of elderly Americans—stroke victims, for example—and triples their risk of death, says engineer Cara Stepp. She hopes to help these patients by having them play video games.

With their necks.

Those last two sentences aren’t typos. There’s some evidence that training the swallow-challenged with unusual tasks may foster faster motor learning than traditional therapy, says Stepp, a Sargent College assistant professor of speech, language, and hearing sciences and a College of Engineering assistant professor of biomedical engineering. “We use noninvasive measurements of your muscle activity as the control signal, so patients literally play the game using their neck. Patients watch a video game screen and activate their muscles when they want to hit a target in the game. Electrodes hooked to the patient signal the game when the patient swallows. Coordinating their muscle activity to the game exercises their throat muscles and may improve their ability to swallow.”

Her work has secured Stepp one of this year’s Peter Paul Professorships, which provide $40,000 in research money annually for three years. Stepp, who has a doctorate from the Harvard-MIT Division of Health Sciences and Technology, says the funding will allow her to hire an assistant and travel to local assisted living centers to record patients.

Kathleen Corriveau, a leading expert in human development at the School of Education, is head of the Social Learning Laboratory. Photo by Vernon Doucette

Kathleen Corriveau, a leading expert in human development at the School of Education, is head of the Social Learning Laboratory. Photo by Vernon Doucette

The other Peter Paul winners are Kathleen Corriveau, a School of Education assistant professor of human development, James Uden, a College of Arts & Sciences assistant professor of classical studies, and Valentina Perissi, a School of Medicine assistant professor of biochemistry.

Corriveau’s research probes the social and cognitive influences that make children decide which adults in their lives can be trusted for reliable information. She has become a go-to source in her field, with her scholarly journal articles cited by peers almost 300 times in just the two years since she received her PhD from Harvard.

“As a junior faculty member, there are always times of self-doubt. Receiving this award gives me the confidence to know that the University believes that I can make a difference through my research,” says Corriveau. The Peter Paul grant will help fund her just-launched Social Learning Laboratory, which studies how children learn. “To learn the shape of the Earth, of the existence of germs, children often cannot rely on firsthand experience and instead have to turn to other people,” she says. “We investigate the cues children use to judge the credibility of the source, as well as how children incorporate the information into their worldview.”

Classical studies expert James Uden, a CAS assistant professor, will use the Peter Paul Professorship to further his book about the Roman satirical poet Juvenal. Photo by Vernon Doucette

Classical studies expert James Uden, a CAS assistant professor, will use the Peter Paul Professorship to further his book about the Roman satirical poet Juvenal. Photo by Vernon Doucette

Uden says his Peter Paul award will further his current project—a book about the Roman satirical poet Juvenal—and perhaps help him begin a new one. “I am becoming interested in ideas of intellectual freedom in the Roman Empire,” he says in regard to the latter. “How independent were scholars from political control? Could scholars become, in effect, critics of the society in which they lived?” Uden earned a PhD at Columbia University.

Perissi, whose doctorate is from the University of California, San Diego, is a cellular and molecular biologist studying “the role of inflammation in obesity-induced type 2 diabetes,” she says. Controlled inflammation helps the body protect itself against injury and disease, but can become harmful if chronic; studying helpful inflammation may lead to ways to keep it from running amok, she says. “I am really excited for this award, which will be critical to get our research going and obtain important preliminary data that will allow us to apply for other fundings.”

Cellular and molecular biologist Valentina Perissi in her lab at the Boston University School of Medicine. Photo by Vernon Doucette

Cellular and molecular biologist Valentina Perissi in her lab at the Boston University School of Medicine. Photo by Vernon Doucette

University trustee Peter Paul (GSM’71) created the professorships named for him in 2006 with a $1.5 million gift, later increased to $2.5 million. President Robert A. Brown and Provost Jean Morrison select recipients from those recommended by deans and department chairmen. The grants are given to promising scholars with two years or less of teaching experience and no previous professorship, who might otherwise have difficulty securing research funding.

Morrison says the grants support the “talented researchers and teachers who are at the core of a successful institution. We extend our deepest gratitude to Paul for his belief in the importance of recognizing and helping to elevate future leaders in the classroom and laboratory.” The awardees’ work “furthers BU’s distinction as a research leader and incubator of exciting new ideas.”

Doctors, Engineers Team Up to Fight Cancer

September 19th, 2012 in BME News

$9 million NIH Grant Founds BU-Based Center

By Leslie Friday

Catherine Klapperich, an ENG associate professor of biomedical engineering and of mechanical engineering and FTCC director, will lead BU's effort to fight cancer by teaming doctors with engineers. Photo by Kalman Zabarsky

Catherine Klapperich, an ENG associate professor of biomedical engineering and of mechanical engineering and FTCC director, will lead BU's effort to fight cancer by teaming doctors with engineers. Photo by Kalman Zabarsky

Imagine a world where a simple mouth swab could predict lung cancer, a blood test could warn of a recurrence of melanoma, and a rectal scan could tell if you would benefit from a colonoscopy.

That world is the vision of the Center for Future Technologies in Cancer Care (FTCC), founded here in July with help from a five-year, $9 million grant from the National Institute of Biomedical Imaging and Bioengineering (NIBIB) at the National Institutes of Health. The center will foster collaboration among doctors, engineers, and public health and business professionals at BU and elsewhere who hope to develop technology to diagnose, screen, and treat a variety of cancers faster, cheaper, and better than is done now.

BU is one of three recipients, with Harvard and Johns Hopkins University, of a U54 award, given by NIBIB’s Point-of-Care Technologies Research Network (POCTRN).

Catherine Klapperich, a College of Engineering associate professor of biomedical engineering and of mechanical engineering and the FTCC director, says this isn’t the first time that BU engineers and clinicians have collaborated to tackle major health problems. The FTCC effort is unique, however, in its focus on cancer care. The new center will draw expertise from programs like the W. H. Coulter Translational Partnership Program and the Boston University/Fraunhofer Alliance for Medical Devices, Instrumentation and Diagnostics and will try to develop and commercialize promising prototypes.

“Cathie understands that cancer is not a high- or middle-income country problem; it’s a global problem,” says Jonathon Simon, director of the Center for Global Health & Development and the School of Public Health Robert A. Knox Professor. “With the increasing longevity of populations in low- and middle-income countries and our ability to manage the infectious disease and maternal mortality burdens, there’s just a lot more cancer that comes about because of the age structure of populations, but also because the competing risks on what else is getting people have been diminished.”

Irving Bigio, an ENG professor of biomedical engineering and electrical and computer engineering, demonstrates how a fiber-optic probe can read tissue samples. Photo by Chitose Suzuki

Irving Bigio, an ENG professor of biomedical engineering and electrical and computer engineering, demonstrates how a fiber-optic probe can read tissue samples. Photo by Chitose Suzuki

The center’s first five seed projects focus on lung, colon, skin, and liver cancers. Avrum Spira (ENG’02), a School of Medicine professor of medicine, pathology, and bioinformatics and a pulmonologist at Boston Medical Center (BMC), has found a way to detect lung cancer at an earlier and therefore far more treatable stage than it is usually found, by studying changes in cells in the windpipes of smokers. With help from the FTCC, he hopes to develop a blood test or mouth or nose swab that could reveal a high risk of lung cancer.

Irving Bigio, an ENG professor of biomedical engineering and of electrical and computer engineering, and Satish Singh, a MED assistant professor of medicine and a BMC gastroenterologist, have teamed up to develop a prescreening tool for colon cancer, the second leading cause of death by cancer in the United States.

Doctors recommend that everyone age 50 and over have a colonoscopy at least once every 10 years, yet compliance is low, Bigio and Singh say, because people dislike the invasive nature of the procedure. Singh notes that only half of those people who undergo a colonoscopy actually have intestinal polyps, and half of those have precancerous polyps. With this in mind, Bigio developed a fiber-optic probe that uses light and a spectrometer to detect potentially cancerous polyps, and thus signal a real need for a colonoscopy. FTCC funding will advance their research, and if it’s successful, help develop a prototype that is disposable and affordable.

Klapperich herself is working with San Francisco–based Wave 80 Biosciences to develop a blood test to detect liver cancer. The researchers are designing a cartridge that would separate the nucleic acid RNA from blood or plasma samples and use isolated nucleic acid to flag liver cancer, which kills more than 20,500 yearly in the United States, according to the American Cancer Society.

Rhoda Alani, MED’s Herbert Mescon Professor and Chair of dermatology, chief of BMC’s department of dermatology, and one of four NIBIB co–principal investigators, hopes to develop a similar technology with colleagues from the University of Texas at Austin that will analyze RNA within patients’ blood samples to determine the likelihood of a recurrence of melanoma, an aggressive form of skin cancer discovered yearly in more than 76,000 people in the United States, according to American Cancer Society figures.

The center’s fifth seed project, a collaboration between MIT and Michigan State University called My LifeCloud, is a cell phone–based system aimed at empowering patients at risk for colorectal cancer—particularly the African American population, which the American Cancer Society says has the highest incidence of, and mortality rate from, colorectal cancer of all racial groups in the United States.

Rhoda Alani, MED's Herbert Mescon Professor and Chair of dermatology and chief of BMC's dermatology department, hopes blood samples are the key to early detection of a melanoma recurrence. Photo by Vernon Doucette

Rhoda Alani, MED's Herbert Mescon Professor and Chair of dermatology and chief of BMC's dermatology department, hopes blood samples are the key to early detection of a melanoma recurrence. Photo by Vernon Doucette

Over the five-year NIBIB grant period, Klapperich says the center will encourage several new proposals, weed out a few, and provide funding for an annual summer innovation fellowship to transition lab research to a working prototype.

The grant will also allow another NIBIB co–principal investigator, Bennett Goldberg, a CAS professor of physics, an ENG professor of biomedical engineering, and director of the Center for Nanoscience and Nanobiotechnology, to lead training workshops and informal meetings at BU and around the country for students, clinicians, and faculty interested in an interdisciplinary approach to tackling cancer.

The other two NIBIB co–principal investigators are David Seldin, a MED professor of medicine and microbiology and BMC’s chief of hematology-oncology, and Arthur Rosenthal, an ENG professor of biomedical engineering and director of the Coulter Translational Partnership Program.

Franklin Huang, a fellow in the department of medical oncology at the Dana-Farber Cancer Institute, will guide the public health side of the center’s pursuits, determining population needs and assessing which advances might have the greatest impact. “One criterion for screening technology,” says the CGHD’s Simon, “is that the movement forward of science should to the greatest extent possible benefit the largest numbers of people.”

Klapperich echoes Simon’s objective to do the greatest good. As engineers, she says, she and her colleagues could sit around and “impress each other with the stuff that we made,” or they could apply their expertise in ways that will do the greatest good.

Morgan Named 2012 Distinguished Faculty Fellow

September 18th, 2012 in BME News

By Mark Dwortzan

Associate Professor Elise Morgan (BME, ME)

Associate Professor Elise Morgan (BME, ME)

Since joining the College of Engineering faculty in 2003, Associate Professor Elise Morgan (BME, ME) has worked to advance our understanding of the role of the mechanical function of tissues and organs in skeletal health, repair and development, with the ultimate goal of pinpointing causes and treatments for osteoporosis, osteoarthritis, poor bone healing, and other diseases and conditions. Based on her research achievements in biomechanics, Morgan was named the College’s 2012 Distinguished Faculty Fellow, an award recognizing mid-career faculty members for significant contributions to their field.

Morgan, who holds a joint appointment in the BME Department, will receive $20,000 per year for the next five years to support her research.

“I am excited and honored to be receiving this award, particularly considering the outstanding caliber of the current and former Fellows,” she said. “The funds provided by this award will allow my research group to make important headway in new areas of biomechanics and regenerative medicine.”

As director of the Orthopaedic and Developmental Biomechanics Laboratory, Morgan studies the interplay among the mechanical behavior, structure and biological function of tissues. Drawing on methods from engineering mechanics, materials science, and cell and molecular biology, and combining experimentation and computational modeling, Morgan’s lab investigates how mechanical factors contribute to the development, adaptation, failure and regeneration of bone and cartilage. Current projects include the use of mechanical stimulation to promote bone regeneration, the biomechanics of spine fractures and bone healing, and non-invasive diagnostics of bone healing.

A new CT scanning technique developed by Morgan allows researchers to see where and how much cartilage (shown in blue) has formed relative to the bone shaft (red). The new technique also identifies other soft tissue (yellow) that surrounds the bone fracture.

A new CT scanning technique developed by Morgan allows researchers to see where and how much cartilage (shown in blue) has formed relative to the bone shaft (red). The new technique also identifies other soft tissue (yellow) that surrounds the bone fracture.

Since earning her PhD in mechanical engineering in 2002 at the University of California, Berkeley, Morgan has received a Ruth L. Kirschstein National Research Service Award for Senior Fellows from the National Institutes of Health, a Young Investigator Research Award from the International Osteoporosis Foundation and Servier Research Group, and an Early Career Research Excellence Award from the College of Engineering.

A member of the American Society of Mechanical Engineers, Orthopaedic Research Society, American Society of Bone and Mineral Research, and American Society of Engineering Education, she has published more than four dozen peer-reviewed articles in major biomedical journals and has delivered more than 30 seminars and invited talks—many at international scientific meetings. She is also the co-founder of a successful outreach program, Summer Pathways, which engages high school girls in a weeklong sequence of activities in science, engineering and math.

In receiving this year’s Distinguished Faculty Fellow award, Morgan joins past recipients Associate Professor Kamil Ekinci (ME), Professor Mark Grinstaff (BME, MSE), Associate Professor Joyce Wong (BME, MSE) and Professor Xin Zhang (ME, MSE).

Densmore Shares DARPA Grant to Design New Synthetic Biology Assembly Line

September 18th, 2012 in BME News

By Mark Dwortzan

Assistant Professor Douglas Densmore (BME, ECE)

Assistant Professor Douglas Densmore (BME, ECE)

Today’s synthetic biologists tend to work in silos, developing novel, biologically engineered materials and devices on dedicated platforms through sophisticated, trial-and-error experiments. As a result, new biologically manufactured products often require more than seven years to build and tens to hundreds of millions of dollars to finance. But a new, more universal synthetic biology platform is emerging that promises to dramatically accelerate the process, enabling on-demand production of new materials and devices, from biofuels to wound sealants, at a much lower cost.

In pursuit of this vision, the Defense Advanced Research Projects Agency (DARPA) has awarded a $3.6 million, 30-month grant to Assistant Professor Douglas Densmore (BME, ECE) and collaborators at MIT, University of California-San Francisco and Pivot Bio (a biotech startup) to help establish a “living foundry” where researchers can access, design, assemble and test synthetic genetic systems composed of hundreds of DNA parts. The new project is administered by DARPA’s Living Foundries Program, which seeks to create an engineering framework for biology that speeds production and reduces its costs by a factor of ten while radically expanding the complexity of systems that can be engineered.

The research team’s proposed method consists of three sequential tasks. The first is to create a library of more than 10,000 modular DNA parts, derived from bacteria, that would serve as biological building blocks.

The team’s second challenge is to develop an automated process to systematically assemble and use these parts to perform specific biological functions, from processing nitrogen to producing antimalarial drugs.

Informed by databases of DNA sequence information and equipped with an extensive library of DNA parts, the MIT team will build gene clusters with the potential to produce corrosion-resistant chemicals called siderophores, and test the resulting siderophores to see how well they work. Densmore will then analyze the DNA used to create the siderophores to determine rules that distinguish gene clusters that work well from those that don't, and use those rules to hypothesize how to take known gene clusters and produce better ones.

Informed by databases of DNA sequence information and equipped with an extensive library of DNA parts, the MIT team will build gene clusters with the potential to produce corrosion-resistant chemicals called siderophores, and test the resulting siderophores to see how well they work. Densmore will then analyze the DNA used to create the siderophores to determine rules that distinguish gene clusters that work well from those that don't, and use those rules to hypothesize how to take known gene clusters and produce better ones.

Densmore will be deeply involved in the third task, which is to apply this process to the production of siderophores, chemicals that bind to metal surfaces and form a protective layer to prevent corrosion, a widespread and costly (an estimated $23 billion per year) problem faced by the Department of Defense, which must operate in some of the most corrosively aggressive environments on the planet. Siderophores could be sprayed on ships, planes and other military vehicles and equipment to prolong their operational lifetimes.

“Our goal is to engineer bacteria that can create siderophore compounds in a more tuned, engineered way so that they are better performing, cheaper to manufacture and faster to produce” said Densmore, who holds a joint appointment in the BME Department. “To accomplish that goal, I will use the Eugene programming language my group has developed to create new gene clusters with machine learning techniques that use rules to bias new designs away from past failures and toward future successes.”

“Doug’s software and background in electrical engineering is critical in managing the design process and extracting actionable information from the data,” said Christopher Voigt, an associate professor of biological engineering at MIT and the project’s principal investigator.

Once the collaborators identify the gene clusters they believe will perform the best, Densmore will synthesize them using liquid-handling robots at BU.

“We envision an automated process in which people send us materials they want to design, we learn from them and improve them, and then we build new ones,” said Densmore. “If our living foundry is really streamlined, robots will test each new material and teach themselves how to build the next one.”

Xue Han Receives NIH Director’s New Innovator Award

September 14th, 2012 in BME News

By Mark Dwortzan

Assistant Professor Xue Han (BME)

Assistant Professor Xue Han (BME)

Assistant Professor Xue Han (BME) has received a 2012 National Institutes of Health (NIH) Director’s New Innovator Award, which supports exceptionally creative, early-career researchers pursuing highly innovative projects with the potential to transform their field of endeavor and bring about improved health outcomes. Chosen from hundreds of applicants from across the U.S., Han and 50 other award recipients were announced at the eighth annual NIH Director’s Pioneer Award Symposium on September 13.

The award, which provides up to $1.5 million in funding for five years, will support Han’s efforts to develop a novel method to study the functions of biomolecules in the brain. The method, which uses nanoscale robots to safely probe a variety of molecules, peptides and proteins in intact brains with pulses of visible light, could open up new frontiers in basic molecular and systems neuroscience, drug development and side effect assessment.

“I am thrilled to receive this award,” said Han. “It will provide tremendous support for my research.”

Han develops and applies high-precision genetic, molecular, optical and electrical tools and other nanotechnologies to study neural circuits in the brain. By using light to momentarily activate or silence individual brain cells, she and her research team seek to identify connections between neural circuit dynamics and behavioral phenomena such as movement, attention, memory and decision-making. Establishing such connections could improve our understanding of cognitive functioning and lead to new treatments to Parkinson’s disease, schizophrenia, attention deficit disorders and other neurological diseases.

Han was also recognized recently as a Pew Scholar in the Biomedical Sciences, Sloan Research Fellow and Peter Paul Fellow.

BME Graduate Student Wins Prestigious Fellowship

August 22nd, 2012 in BME News

By Mark Dwortzan

BME graduate student Darash Desai

BME graduate student Darash Desai

The U.S. Pharmacopeial (USP) Convention has selected BME graduate student Darash Desai as a USP Research Fellow, awarding him one of three $50,000 fellowships for the 2012-13 academic year.

The first College of Engineering student to receive this honor, Desai is the main developer of PharmaCheck, a low-cost, portable, robust, comprehensive diagnostic device that he and his PhD advisor, Associate Professor Muhammad Zaman (BME), are advancing to enable local health authorities to screen for substandard or counterfeit anti-malarials, antibiotics and other essential medicines. The need for such a device is particularly acute in the developing world, where counterfeit and substandard drugs are commonplace, leading to thousands of preventable deaths.

“We were thrilled to receive the award, which will go a long way in providing resources not only to complete development of the device, but also to leverage expertise in the area of counterfeit and substandard medicines screening,” said Desai, whose research involves a collaborative effort with the USP and the U.S. Agency for International Development (USAID).

“The award is a testament to the fact that there is a broader appeal and appreciation for this technology that is shared by not just people in development circles but also among the most prestigious pharmaceutical and pharmacopeial communities,” said Zaman.

Founded in 1820, the USP is a scientific nonprofit organization that sets standards for the identity, strength, quality and purity of medicines, food ingredients and dietary supplements manufactured, distributed and consumed worldwide—standards enforceable in the U.S. by the Food and Drug Administration, and relied upon in more than 140 countries.

Who Said That?

August 21st, 2012 in BME News

BME Researchers Probe Common, Age-Related Hearing Problem

By Mark Dwortzan

Selective attention is the auditory system's ability to distinguish among multiple sound sources in noisy environments. Degraded selective attention compromises middle-aged and older individuals' ability to decipher who said what, leading some to avoid social gatherings and stay home. Professor Barbara Shinn-Cunningham (BME) (at table) is shown with young members of her lab engaged in multiple conversations.

Selective attention is the auditory system's ability to distinguish among multiple sound sources in noisy environments. Degraded selective attention compromises middle-aged and older individuals' ability to decipher who said what, leading some to avoid social gatherings and stay home. Professor Barbara Shinn-Cunningham (BME) (at table) is shown with young members of her lab engaged in multiple conversations.

The older you get, the harder it gets to communicate at restaurants, parties and other common social settings where sound reverberates, but ordinary hearing loss is not the primary reason. According to a new College of Engineering study funded by the National Institutes of Health, the main culprit is selective attention, the auditory system’s ability to distinguish among multiple sound sources in noisy environments. Degraded selective attention compromises middle-aged and older individuals’ ability to decipher who said what, leading many seniors to avoid social gatherings and stay home.

The study’s authors—Professor Barbara Shinn-Cunningham (BME), Dorea Ruggles (BME PhD’12) and BME PhD student Hari Bharadwaj—reported their findings in the June 21 online edition of Current Biology.

Having shown in a previous study that one’s auditory sensitivity threshold—the decibel level below which one cannot detect sounds—does not predict how well one can pinpoint sound sources, the researchers set up this study to establish a clear link between age and selective attention capability.

Toward that end, they equipped 22 listeners aged approximately 21 to 55—all with normal auditory sensitivity thresholds—with headphones simulating three competing speakers with the same voice, positioned 15 degrees to the left of the subject, directly in front, and 15 degrees to the right. As the competing speakers enunciated sequences of digits (1, 2, 3, etc.), subjects were asked to report the numbers they heard from the source positioned in front of them. They completed the test in three simulated auditory environments: a pristine, echo-free chamber without walls; a normal room with ordinary walls; and an extremely reverberant space, akin to a tiled bathroom.

When switching from the pristine to the normal environment to execute this task, the oldest subjects showed the greatest decline in selective attention. In the extremely reverberant space, most picked numbers randomly.

“Selective attention differences between younger and older subjects only showed up in real-world environments in which sound reverberates off walls,” said Shinn-Cunningham. “The spatial cues in sound in a real room are very different than what most people experience in an echo-free room.”

In echo-free environments, the brain relies primarily on low-frequency sound waves to estimate where the sound is coming from, but in natural settings with reverberant noise, low-frequency sound signals get distorted before they reach the auditory system. Whereas younger listeners can interpret mid-to-high-frequency sound signals to pinpoint sound sources in reverberant environments, middle-aged listeners are less able to process these signals due to age-related physiological changes in the auditory brainstem, Shinn-Cunningham speculates.

“Common hearing aids are not designed to amplify high-frequency sound because it’s not critical to understanding speech content,” she observes. “Providing this capability may help older individuals to direct their attention in in social situations that would otherwise be daunting.”

BME Graduate Students Take Top Prizes at BU Translational Research Symposium

August 21st, 2012 in BME News

By Mark Dwortzan

BME graduate student Kyle Allison (center) and his first prize-winning poster at Boston University's third annual Translational Research Symposium.

BME graduate student Kyle Allison (center) and his first prize-winning poster at Boston University's third annual Translational Research Symposium.

PhD students in the Biomedical Engineering Department received all three poster session awards at Boston University’s third annual Translational Research Symposium, a gathering of researchers from across the campus who are engaged in efforts to transform innovative biomedical concepts into practical health care applications. Organized by the BU Clinical and Translational Science Institute (BU CTSI) and held at the BU Metcalf Trustees Center, the daylong symposium featured talks by BU College of Engineering and BU School of Medicine (BUSM) faculty and posters by 52 BU graduate students and postdoctoral fellows focused on clinically relevant biomedical research.

Honored for their exceptional scientific posters by a panel of nine judges representing the College of Engineering, School of Medicine, School of Public Health and other BU administrative units, BME graduate students Kyle Allison, Ben Lakin and Kevin McHugh (tied with Charles Dumont, MD, BUSM Sections of Pulmonary and Computational Biomedicine, Department of Medicine) received first ($1,000), second ($500) and third ($250) prizes, respectively.

“The BME Department should be proud of their students’ accomplishments,” said BU CTSI Director and Associate Provost for Translational Research David M. Center, M.D. “The winners were chosen based on the quality of the science and its translational applicability.”

Allison, Lakin and McHugh were first authors on posters involving collaborations with researchers at BU, Harvard Medical School, Boston Children’s Hospital, Beth Israel Deaconess Medical Center and the Charles Stark Draper Laboratory.

Allison and his collaborators—Professor James J. Collins (BME, MSE, SE) and Research Associate Mark Brynildsen (BME)—submitted a poster on the novel strategy they developed to eradicate antibiotic resistant bacterial infection. Combining a class of antibiotics called aminoglycosides with simple sugars, such as glucose, mannitol and fructose, the researchers showed they were able to kill a variety of such bacteria, and improve chronic urinary tract infection in a mouse model.

Lakin and his research team—including Professor Mark W. Grinstaff (BME, MSE)—submitted their poster on an interdisciplinary study that provides experimental evidence predicting that a novel contrast agent can be injected locally during a CT scan to monitor changes in the biomechanical properties of cartilage. Their study could lead to improved diagnostics for osteoarthritis, the most common joint disorder, and for monitoring the impact of treatment on the disease.

McHugh and his research partners’ poster described a porous film they created that can be implanted in the eye to treat age-related macular degeneration disease, the leading cause of blindness in old age in the developed world. The film, which stimulates regeneration of tissue in the treatment area, shows great promise not only to treat macular degeneration but also to generate new tissues to reverse other degenerative diseases.

The symposium featured talks by BUSM and College of Engineering faculty members, including keynote speaker Collins, who spoke on “Translational Network Biology: Synthetic Biology, Systems Biology and Microbial Threats;” Assistant Professor Tyrone Porter (ME) on “Stimuli-Responsive Nanoparticles for Drug and Gene Delivery;” and Assistant Professor Douglas Densmore (ECE) on “Automatically Specifying, Designing, and Assembling Biological Systems.”

Funded by the National Institutes of Health, the BU CTSI seeks to speed the translation of medical innovations that improve the diagnosis and treatment of diseases and to share these innovations with other university-based clinical and translational science programs.

Introducing the 2012 Lutchen Fellows

August 21st, 2012 in BME News

By Mark Dwortzan

The Lutchen Distinguished Fellowship Program supports up to 10 undergraduate research projects each summer. Nine of this year's 10 Lutchen Fellows are shown here with Dean Kenneth R. Lutchen: Catherine Chan-Tse (EE'13), Hyung Jin (Peter) Sun (ME'13), Alberto Purwada (BME'13), Ajay Rajshakar (BME'14), Veronica Faller (BME'13), Robert Lebourdais (BME'14), Gabriel Begun (CE'14), Angela Lai (BME'14) and Thomas Howe (ME'13).

The Lutchen Distinguished Fellowship Program supports up to 10 undergraduate research projects each summer. Nine of this year's 10 Lutchen Fellows are shown here with Dean Kenneth R. Lutchen: Catherine Chan-Tse (EE'13), Hyung Jin (Peter) Sun (ME'13), Alberto Purwada (BME'13), Ajay Rajshakar (BME'14), Veronica Faller (BME'13), Robert Lebourdais (BME'14), Gabriel Begun (CE'14), Angela Lai (BME'14) and Thomas Howe (ME'13).

Ten rising juniors and seniors are pursuing research with societal impact this summer as winners of this year’s Kenneth R. Lutchen Distinguished Fellowships. Drawing on their engineering knowledge and skills to improve society, their work could lead to advances in everything from energy harvesting to heart disease diagnostics.

“The application process this year was very competitive, with many more applicants with compelling projects than we could support,” said Sol Eisenberg, associate dean for Undergraduate Programs. Each fellow must maintain a minimum 3.0 grade point average and choose a research project working with an engineering faculty mentor.

Five of the 2012 Lutchen Fellows are pursuing projects focused on improving our understanding of biological processes and identifying potential treatments for specific illnesses. Taking aim at cardiovascular disease, Alberto Purwada (BME’13) is investigating how smooth muscle cell behavior within blood vessels is altered by changes in the local environment during the progression of atherosclerosis, and Hyung Jin Sun (ME’13) is studying mechanisms behind the stiffening of blood vessels.

Veronica Faller (BME’13) is probing protein-protein interactions that scientists suspect are involved in controlling the metabolism of the bacterium that causes tuberculosis, possibly prolonging its survival in human hosts. Ajay Rajshakar (BME’14) is conducting experiments on bovine lung behavior, with the ultimate goal of identifying new pathways to treat asthma and other respiratory diseases. Catherine Chan-Tse (EE’13) is using a specialized microscope to track fluorescent-tagged molecules. Tracking of proteins and other biomolecules could enable new insights and treatments for cardiac, brain and other diseases.

Two Lutchen fellows are contributing to the development of advanced healthcare technology. Angela Lai (BME’14) is exploring the development of a credit card-sized, microfluidic chip that could be used as a point-of-care diagnostic test for the sexually transmitted disease gonorrhea. Robert Lebourdais (BME’14) is mathematically modeling processes that impact the performance of Professor Edward Damiano (BME) and his team’s software-controlled artificial pancreas, which automatically administers insulin and glucagon to maintain desirable blood sugar levels in people with diabetes.

Finally, three Lutchen Fellow projects entail automating or analyzing complex processes. Gabriel Begun (CE’14) is working on a hardware and software system that combines video and audio to detect certain objects, such as an approaching human being, with greater accuracy than systems that rely on video or audio signals alone. Thomas Howe (ME’13) is modeling and optimizing a miniature energy harvesting system that would mechanically attach to your cell phone or other electronic device and charge the battery as you walk. Lisa Rooker (EE’14) is investigating interactions between a class of low frequency electromagnetic waves and plasma in the ionosphere above Gakona, Alaska. Rooker’s research could lead to a better understanding of the ionosphere and enhanced radio communications and surveillance systems.

The Lutchen Distinguished Fellowship program has been funded since 2010 by annual donations of $100,000 from an anonymous alumnus of the College’s Biomedical Engineering program.