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The newspaper of The Johns Hopkins University March 7, 2005 | Vol. 34 No. 25
A Bridge to Exploration

PURA grants in hand, 45 undergrads move into the world of research

Whether it's conducting epidemiological studies in a remote Indian village, constructing artificial cockroach antennae or playing alongside legendary Scottish folk musicians, the axiom of learning through doing is what lies at the heart of the Provost's Undergraduate Research Awards.

On Thursday, March 10, Steven Knapp, university provost and senior vice president for academic affairs, will host the 12th annual PURA Awards ceremony, which will honor the 45 winners who conducted their projects in the summer and fall of 2004. Since 1993, about 40 students each year have received PURA grants of up to $3,000 to conduct original research, some results of which have been published in professional journals. The awards, funded through a donation from the Hodson Trust, are an important part of the university's mission and its commitment to research opportunities for undergraduates.

The Provost's Undergraduate Research Awards are open to students in each of the university's four schools with full-time undergraduates: the School of Arts and Sciences, the School of Engineering, the Peabody Conservatory and the School of Nursing.

The 2005 ceremony will be held in the Glass Pavilion at Homewood. The entire Hopkins community is invited to the event, which begins at 3 p.m. with an informal poster session allowing students to display and talk about their projects. An awards ceremony hosted by Knapp will begin at 4:30 p.m. and will be followed by a reception. PURA recipient Robert Whelan will help kick off the ceremony with a musical presentation on his look into the Shetland Islands folk tradition.

Whether their awards took them near or far, students often find the true rewards lie in the journey to discovery. This year was no different. A sampling of the winners follows.



CAN A BRIDGE BE STRUCTURAL ART? Civil engineering major Christina Terpeluk on a Bollman truss bridge in Savage, Md.

To most people, a bridge is simply an assembly that allows travelers to move safely across a river or some other expanse. But to senior Christina Terpeluk, a bridge can be a piece of structural art. To qualify, it must be a work of elegance and efficiency that showcases its designer's engineering goals in a way that appeals to the eye.
    Supported by a PURA, Terpeluk has spent months studying 19th-century American iron truss bridges, trying to determine whether they fit the definition of structural art, a concept championed by David P. Billington, a civil engineering scholar at Princeton. For her project, Terpeluk has conducted detailed studies of three types of truss bridges built more than a century ago.
    The work has required the civil engineering major to run 21st-century computer programs and pore through fragile 19th-century manuscripts. Beyond the bridges' obvious role as transportation infrastructure, Terpeluk has explored their social, economic and symbolic values, trying to determine what the bridges meant to the communities they served.
    She believes her research is opening new scholarly terrain. "There has been a lot of 'history of technology' material written about these bridges," she says. "But there is almost nothing about the connection between aesthetics and engineering in them. It surprised me how much I didn't know."
    Structural art, as opposed to fine architecture, has become an intriguing new field of study, says Sanjay R. Arwade, assistant professor of civil engineering and Terpeluk's faculty research sponsor. An architect often designs pleasing shapes independent of the structural skeleton of a building, Arwade says. But in a work of structural art — the Eiffel Tower is a prime example — the engineering is fully visible, efficiently designed and aesthetically pleasing in its own right. "A main idea," he says, "is that you should be able to look at the structure and 'read' it from an engineering standpoint."
    Terpeluk's affection for bridges dates back to her freshman year at Johns Hopkins, when an introductory class required her to build a sturdy model bridge out of spaghetti strands and glue. She enjoyed the experience so much that she promptly switched her major from general engineering to civil engineering.
    Later, after taking a course called Perspectives on the Evolution of Structures, co-taught by Arwade, Terpeluk decided to apply this standard to 19th-century American iron truss bridges. Truss bridges use a latticework of triangles to handle the forces of tension and compression when a vehicle passes over them. After a long period in which wooden bridges dominated the American landscape, 19th-century engineers began competing to design more efficient, less expensive iron truss bridges, primarily for railroads.
    Terpeluk focused on three types of bridge designs — the Whipple truss, Fink truss and Bollman truss — and studied examples built in Frederick, Md.; Hamden, N.J.; and Savage, Md. She used a computer program to conduct structural analyses of the bridges and employed traditional research tools to delve into the social, economic and symbolic background of the structures. "At the [university's] Peabody Library, I found documents from that time period focusing on bridge design," she says. "It was an awesome experience."
    In addition, while completing an internship at a London engineering firm last summer, she was able to visit a number of truss bridges in the British Isles. That enabled her to draw comparisons between British and American bridges from the same period.
    Terpeluk hopes to publish her findings in a peer-reviewed journal or present them at an engineering conference. "I've learned a lot about doing research," she says. "It's not an easy task."
    After graduating in May, she plans to attend graduate school and prepare for a career involving the restoration or rehabilitation of historic structures.
— Phil Sneiderman



PREDICTING HEART FAILURE: Samuel Hahn with Gordon Tomaselli, professor of medicine, and Fadi Akar, a research assistant professor in Tomaselli's lab.

Samuel Hahn, a senior majoring in biomedical engineering, has contributed to new research showing that electrical changes in the heart leading to heart failure can occur long before a patient exhibits any clinical symptoms. The initial changes can then spur a second, later phase of changes that cause lethal heart rhythm disturbances known as arrhythmias.
    The study by Hahn and Fadi G. Akar, a research assistant professor at the School of Medicine, was the first to describe the time-course and nature of electrical abnormalities occurring during the development of heart failure. A manuscript of their work has been submitted to a peer-reviewed scientific journal. The two conducted their research in the laboratory of Gordon F. Tomaselli, professor of medicine and vice chair for research in the Department of Medicine.
    "By the time most patients are diagnosed with heart failure, it's too late to really improve their condition," Akar says. "By defining the early electrical changes, we hope to identify new targets for therapy that can either reverse or, at the very least, hinder the progression of the vicious cycle of events that ultimately leads to death."
    During heart failure, the pumping action of the heart becomes inadequate, resulting in a back pressure of blood along with congestion of the lungs and liver. Nearly 5 million Americans suffer from heart failure, and more than 250,000 die annually from the condition, Hahn says. The incidence and prevalence of the disease continue to increase with the aging of the U.S. population.
    "Despite remarkable improvements in medical therapy, the prognosis of patients with heart failure remains very poor, with almost 20 percent of patients dying within one year of initial diagnosis and over 80 percent within eight years," Hahn says. "Of the deaths in patients with heart failure, up to 50 percent are sudden and unexpected, and the result of lethal arrhythmias."
    For their study, Hahn and Akar isolated samples of heart tissue about the size of a large postage stamp from dogs in various stages of heart failure. Next, using a technique called optical mapping, they stained the tissue samples with voltage- or calcium-sensitive dyes and shone a green light on the samples to excite the photosensitive dyes. The excited photosensitive dyes emitted light in different amounts depending upon the cellular voltage or calcium levels in the individual tissue samples. The emitted light was then collected by a sensitive optical detection system, converted to current and stored on a computer for analysis.
    Hahn and Akar were able to demonstrate that electrical disturbances occurred in two distinct phases relative to mechanical abnormalities. The early changes involved a delay in the timing of electrical recovery of the heart muscle following each beat, whereas the later changes involved the loss of electrical synchrony among various regions of the heart. The early electrical changes likely contributed to mechanical abnormalities of the heart, and the later changes were a consequence of the compromised mechanical function. The scientists found that both the early and late changes in the electrical properties were required to cause a lethal arrhythmia.
    "Sam was instrumental in analyzing the data and helping perform the experiments," says Akar, noting that their procedure was a two-person job: one to ensure the health of the heart tissue being studied, and a second to ensure the performance of all experimental protocols and the proper acquisition of data by the computer.
    "He's been a huge mentor for me," Hahn says of Akar. "Being an undergraduate, you still have to have direction. He's given me guidance, freedom and credit."
    Tomaselli also praised Hahn for his persistence and devotion to the project.
    "I am often hesitant to take on undergraduate students, particularly during the most rigorous parts of their programs, but I made an exception for Sam, and I am glad that I did," Tomaselli says. "Sam is the type of student who has the attributes to become a leader in biomedical research."
    After graduating in May, Hahn plans to attend medical school. "I hope to primarily be a clinical physician," he says, "but I definitely would love to have the freedom to pursue questions in medicine that I may have through research."
— Karen Blum



FIDDLING AROUND IN THE SCOTTISH ISLES: Robbie Whelan spent five weeks last summer in the Shetland Islands researching their musical folk tradition.

History major Robbie Whelan describes the Shetland Islands as a melting pot of folk tradition. In its fiddle tunes and dance reels, he says, you can hear the influences of Irish, American, Scottish, Scandinavian and seemingly every Anglo culture in the world. But when the tunes reach these shores, located off the northern coast of Scotland, they become "Shetlandized."
    "The folk songs composed here are defined by a spooky, northern feel," Whelan says. "They're lively, but hard to dance to — although somehow people manage it. You know a Shetland tune when you hear it."
    Whelan, a junior, spent five weeks in the Shetland Islands and two weeks in eastern Scotland researching his PURA project, titled "Han' Me Doon Da Fiddle: Making Links Between the Ethnomusicology and Historical Memory of the Shetland Isles." The project's title was taken from one of folk legend Tom Anderson's collected musical works, known as the bible of the Shetland fiddler.
    An avid fan of folk music and an accomplished player, Whelan was in a traditional Irish band in high school that landed a place in a national competition in Ireland. He says his parents instilled in him a love of folk, in particular the traditional music of Ireland and Scotland.
    The Shetlands, known for their ponies and archaeological sites, consist of about 100 islands, 29 of which are inhabited. They were occupied by Norse invaders and colonists after the late ninth century and were annexed by Scotland in 1472. Whelan spent his days there primarily in town archives looking for publications penned by folk culture groups. He also read scores of letters and newspaper articles, trying to make the case that Shetland folk music is part of the native peoples' greater identity in historical terms.
    A Writing Seminars minor and the co-arts editor of The Johns Hopkins News-Letter, Whelan interviewed several of the islands' elder statesmen of folk: men like Peerie Willie Johnson and Eric Isbister, who has lived on the Shetlands' Foula Island all his life. Whelan was also fortunate enough to play alongside some of the islands' young musicians at various seaside pubs. At the March 10 PURA ceremony, Whelan will bring photos of some of these performers, along with a CD featuring excerpts of the 70 hours of music he recorded while on the Shetlands.
    For those five weeks, Whelan says he felt a bit like Sir Walter Scott, referring to the Scottish novelist and poet. In fact, he says as much in an essay he wrote upon his return to Baltimore.
    "Where he [Walter Scott] was searching for material to titillate the 19th-century upper classes, I was searching for fiddle music, its history and its meaning in the modern world," he wrote. "Our adventures took us to the same windswept cliffs and beaches, teeming with sea birds, the same ancient forts, or brochs, and something like the same firesides in tiny island croft-houses, with tea kettles hanging from the ceilings and fiddle tunes ringing off of the walls."
    Susan Weiss, who was Whelan's sponsor and his professor in a medieval and Renaissance course at Peabody, says that what struck her about Whelan's work was how he took his interest in Irish pub music and Shetland fiddling and transformed it into an experience that drew together many other interests and abilities.
    "And by preparing himself in the techniques of ethnography before he left for the Shetland Isles, he arrived better able to take advantage of the many opportunities to interview, record and play together with local musicians of all ages," says Weiss, a musicologist at Peabody. "His colorful account reveals someone whose attitude toward research and investigation has developed in ways that might not have been possible had he not been afforded the opportunity provided by the PURA."
— Greg Rienzi



TRIBAL HEALTH: Hari Prabhakar, seen here in Tamil Nadu, India, studied the success of the Tribal Health Initiative that brings low-cost care to remote communities.

Hari Prabhakar's PURA grant helped him learn more about the health care gap facing tribal people in his parents' homeland, India. Last summer, he traveled to Tamil Nadu — the state in which his parents grew up — to study the success of the Tribal Health Initiative, started in 1993 to provide low-cost medical care to remote tribal communities.
    The social, political and economic constraints of the caste system make it difficult for tribal citizens to gain access to allopathic health services in the rural areas of their inhabitance, Prabhakar says.
    "People in tribes are below the bottom ranks of the caste system," he says, adding that the disparity between tribal treatments and those offered by modern medicine are a cultural hurdle.
    Ten percent of India's population is affected, but it's a problem that isn't widely recognized, he says. An annual traveler to India, Prabhakar wasn't aware of the situation until he came across a profile in the Indian version of Reader's Digest of the two doctors who created THI. Inspired by their work, Prabhakar wrote to the doctors to ask if he could visit them to study their program. He planned a three-month clinical study of THI from an epidemiological perspective, tracking infant mortality, genetic disorders, gastrointestinal disorders and tuberculosis. He found that those numbers have improved thanks to THI's presence.
    The results of the THI infectious diseases study will be published by the National Medical Journal of India.
    While Prabhakar was concentrating on the relative appearance and magnitude of those four health issues, he also noticed that the rate of sickle-cell anemia among tribal people was unexpectedly high. This turn led Prabhakar to co-author a paper about managing the disease that has been accepted for publication by the Medical Anthropology Quarterly and which was presented on Feb. 6 at the Sickle-Cell Anemia Conference in Wayanad, India, hosted by the Indian Council of Medical Research and the Swami Vivekananda Medical Institute.
    That Prabhakar discovered something outside his intended path isn't surprising to his PURA adviser, Veena Das, chair of the Anthropology Department.
    "What has impressed me most about Hari is his intellectual curiosity along with the ability to work in very difficult circumstances and to organize interventions in an effective manner," Das says. "He is able to learn in new environments, and though he sees complexity, he is not paralyzed by it."
    To supplement his epidemiological study, the physicians invited Prabhakar to travel with them to remote villages and observe their treatment of tribal people. Prabhakar's fluency in Tamil, the predominant language of the region, was a welcome surprise to the patients.
    "The tribal populations of the area are people very grateful and accepting of the health care interventions that are offered to them by external sources," says Prabhakar, a sophomore majoring in public health and the Writing Seminars.
    Writing in an e-mail from India, Regi and Lalitha George, the couple who started the Tribal Health Initiative, said, "Hari is a young and very enthusiastic budding doc — very concerned about the tribals. It is difficult to find young people like him who are sensitive to the underprivileged."
— Amy Cowles



DEPRESSION AND HIGH-RISK BEHAVIORS: Janet Kuramoto, a public health studies major, conducted research in the field of HIV/AIDS and injection drug use.

Janet Kuramoto said that she often found herself "starting from scratch" when it came to her research project.
    A junior public health studies major, Kuramoto conducted research in the field of HIV/AIDS and injection drug use. Specifically, Kuramoto studied the association between depressive symptoms and HIV-related risk behavior. She worked from HIV-prevention studies and surveys conducted by the lab of Carl Latkin, as associate professor in the Department of Health Policy and Management at the Bloomberg School of Public Health.
    Kuramoto says that from Latkin's data she was able to find a significant relationship between the display of depressive symptoms and high-risk behavior, such as injection drug use, among urban poor.
    The journey to her conclusions, however, was far from straightforward.
    "I wasn't really familiar at all with the area of injection drug use, and this was the first time I was doing serious research," she says. "I had to learn a lot about research methods. These were things I went over in class, but when I actually had to implement them, I realized I still had a lot to learn."
    Kuramoto says that her mentors were able to help her turn corners and lead her away from blind alleys with constructive feedback, whether through face-to-face meetings or e-mail queries.
    "Dr. Latkin and my other mentors were really helpful, guiding me through my statistical analysis," she says. "Often I thought I had something, but when it came down to it, I had to start from scratch. There are so many variables and limitations to consider when doing this kind of analysis, you cannot simply make an assertion."
    Hope Gilbert, one of Kuramoto's mentors and a research scientist in the School of Public Health, says that the young student has produced "stellar" statistical work.
    "The most exciting thing that Janet has achieved with this study was to show statistical differences between the gender-specific models that she developed to assess the relationships of HIV [and] drug risk behaviors," Gilbert says. "She has done great work to address gaps in the literature that surround gender differences and injection drug use behaviors."
    Gilbert says that Kuramoto gave 100 percent to the project and challenged herself to step outside the box and address new issues in the field of HIV/AIDS research among injection drug users.
    "Janet is already an amazing researcher," she says. "I knew when she proposed her project that she was going to be an exceptional student, and she has far surpassed my goals for her this year. She has explored many different models and biostatistical methods that are used in advanced public health research, and I am extremely proud of her and of the work that she has done on this project. I have no doubts that one day, Janet will make great contributions to the public health field in her professional career."
— Greg Rienzi



LEARNING FROM COCKROACHES: Owen Loh, working with Brett Kutscher and Noah Cowan, created an antenna that lets a robot move easily in dangerous locations.

Can a robot learn to navigate like a cockroach? To help researchers find out if a mechanical device can mimic the pesky insect's behavior, mechanical engineering major Owen Loh has built a flexible, sensor-laden antenna. Like a cockroach's own wriggly appendage, the artificial antenna sends signals to a wheeled robot's electronic brain, enabling the machine to scurry along walls, turn corners and avoid obstacles.
    The work is important because most robotic vehicles that are sent into dangerous locations rely on artificial vision or sonar systems to find a safe path. But robotic eyes don't operate well in low light, and sonar systems can be confused by polished surfaces. As an alternative, Noah J. Cowan, an assistant professor of mechanical engineering, is turning to the sense of touch, drawing inspiration from bugs that move quite skillfully through dark rooms with varied surfaces.
    The key, Cowan says, is the cockroach's antennae, which touch adjacent walls and alert the insect to obstacles. As a postdoctoral fellow at the University of California, Berkeley, Cowan collaborated with researchers at Stanford University to build a crude antenna to show that a moving machine could use the same technique. After joining the faculty at Johns Hopkins, he assigned Loh to build a more complex antenna to permit more advanced experiments with a cockroach-inspired robot.
    In fall 2003, Loh began studying cockroach biology and working up designs for a robot antenna based on the insect model. "I liked the idea of combining biology and robotics," he says.
    As a junior last spring, Loh received a PURA that would allow him to continue this work in Cowan's lab during the summer. At summer's end, when the lab team quickly needed an antenna for critical robotic experiments, Loh assembled a simple but effective prototype in less than a week.
    These experiments resulted in a peer-reviewed paper that has been accepted for presentation in April at the International Conference on Robotics and Automation in Barcelona, Spain. Loh, who is listed as second author on the paper, plans to attend with Cowan and other members of the lab team.
    In recent months, Loh has fabricated a more advanced version of the antenna. This model is made of cast urethane, a flexible rubberlike substance, encased in a clear plastic sheath. Embedded in the urethane are six strain gauges — sensors that change resistance as they are bent. "We've calibrated the antenna so that certain voltages correspond to certain bending angles that occur as the antenna touches the wall or some other object," Loh says.
    This data is fed to the robotic's controller, enabling it to sense its position in relation to the wall and to maneuver around obstacles. When the antenna signals that the robot is veering too close to the wall, the controller steers it away.
    The newer version of the antenna is being tested by Brett Kutscher, a former PURA recipient, who recently finished his master's degree thesis in Cowan's lab. Cowan believes the cockroach-inspired antennae being developed by his team could eventually provide a new generation of robots with an enhanced ability to move safely through dark and hazardous locations, such as smoke-filled rooms strewn with debris.
    He says Loh provided crucial assistance. "Owen brought a set of skills to that lab that none of us had," Cowan says. "I'm more of an abstract and theoretical researcher. Owen is very good at making things with his hands."
— Phil Sneiderman



UNDERSTANDING VISUAL INFORMATION: Chinyere Ogbonna, holding sign, and Melanie Palomares conducted experiments under sponsor Barbara Landau, standing.

Chinyere Ogbonna, a senior majoring in behavioral biology, is playing an important role in discovering how genetic differences may influence how human beings process and understand visual information.
    Her original research, focusing on how the brains of people with a rare genetic disorder called Williams syndrome perceive visual illusions, was supported by her PURA.
    Ogbonna recognized that people with Williams syndrome were so spatially impaired that they could not copy simple patterns as well as the average 6-year-old. Working with Melanie Palomares, a graduate student in the Department of Psychological and Brain Sciences, Ogbonna hypothesized that this was because those with the disorder simply didn't see the pattern accurately.
    Working under sponsor Barbara Landau, the Dick and Lydia Todd Professor in the Department of Cognitive Science, Ogbonna and Palomares decided to test this hypothesis using something called "visual illusions": simple pen and ink illustrations that attempt to "trick" the viewer's brain into, for instance, thinking one line is longer than the other. According to the researchers, such illusions are crucial evidence that the normal visual brain sees the world by automatically putting together parts to make an understandable "whole."
    With Palomares' help, Ogbonna showed her visual illusion cards to several groups of normal people: 3- to 4-year-olds; 5- to 6-year-olds; 7- to 10-year-olds and adults. She also showed them to people with Williams syndrome who were between the ages of 10 and 41, with the average being 19 years old.
    "We found that when normal people saw parallel lines of equal length that are surrounded by 'railroad tracks' — tilted perpendicular lines — the visual part of their brain tricked them into thinking that the parallel lines were not equal in length," Ogbonna says.
    Surprisingly, they found that those with Williams syndrome reacted the same way.
    "We were amazed that people with Williams syndrome tested just like normal adults, which is not what we expected, based on previous studies of people with this genetic disorder," Ogbonna says.
    Landau, who has studied Williams syndrome for years, calls Ogbonna and Palomares' results nothing less than "brilliant."
    "The idea of using visual illusions as the test was just an amazing idea," Landau says. "And the result was very striking and clear. People with Williams syndrome are severely impaired spatially. They cannot drive a car. They are moderately retarded. The fact that they perform on these tasks the same way that normal, average people do is remarkable, and has the potential to tell us a great deal about how we process and understand visual information. Both Ogbonna and Palomares are brilliant young scientists, with all of the creativity and motivation needed to be successful in life. It's really been a privilege to work with both of them."
— Lisa De Nike



HEART RESEARCH TIMES TWO: Biomedical engineering majors Guarav Gupta and Chris Gregg conducted separate studies in the lab of Dan Berkowitz.

Gaurav Gupta and Chris Gregg, biomedical engineering majors working in the lab of a medical researcher, are conducting separate studies that could lead to improved treatments for heart disease.
    Gupta, a sophomore, has found that mice deficient in the "anti-aging" gene klotho are a good model for age-related blood vessel stiffening. Gregg, a senior, has discovered a signaling pathway through which cells regulate the heart's ability to contract. Both PURA-funded projects were conducted in the lab of Dan E. Berkowitz, an associate professor of anesthesiology and critical care medicine in the School of Medicine with a secondary appointment in Biomedical Engineering.
    Berkowitz praised both Gupta and Gregg for their diligence and drive. "They were the ones always coming to me, asking if I'd seen a recent journal article or suggesting what their next studies should be," he says. "Of all the students I've mentored, the ones that are motivated, resourceful and take the most initiative are the ones that succeed. My role is to focus their energy, like a lens."
    Gupta, who has worked in Berkowitz's lab since his freshman year, says he likes its congenial atmosphere. With several undergraduates working there, he says, the students learn from each other, becoming experts in specific laboratory techniques.
    Gupta studied the cardiovascular biology of aging. In the aging cardiovascular system, abnormal dilating signals sent by the chemical nitric oxide, as released by the endothelial cells lining blood vessels, contribute to increased risk of heart disease. Among the effects of impaired endothelial function is an increase in vascular stiffness, or arteriosclerosis, a contributor to cardiac-related death.
    To study this phenomenon, Gupta compared normal mice to a population of mice bred to be deficient in klotho, a gene with "anti-aging" properties. The latter mice exhibit a syndrome resembling human aging, including vascular stiffness.
    Gupta took blood vessels from the mice and sectioned them into rings. He then suspended the rings between two tiny stirrups attached to a machine that measured how tightly the vessels constricted and recorded the information on a computer. He then applied different chemical agents to the rings. He observed a weak response to acetylcholine, a natural chemical responsible for muscle contraction, indicating that the endothelial cells were not working properly and that the signal pathway for nitric oxide was altered. The appearance of blood vessels in the klotho-deficient mice was consistent with human aging.
    The research could help identify therapeutic targets for the treatment of age-related dysfunction of the endothelial cells lining the walls of blood vessels — a major determinant of vascular disease, Gupta says.
    "By discovering the pathway interactions in age-related endothelial dysfunction, anti-aging therapies can be developed for the cardiovascular system," Gupta says. "Not only does this research open new doors for drug therapy, but it also will allow for further research into the interaction of cholesterol and vascular stiffness in conditions such as atherosclerosis and coronary artery disease."
    Gupta plans to build on this work by evaluating the ability of other medications, such as statins or cholesterol-lowering drugs, to improve vascular stiffening. He is applying for funding from the Howard Hughes Medical Institute.
    Gregg, the lab's other PURA recipient, studied the heart's beta adrenergic receptors. These chemical messengers are critical for intervening in responses to physical activity or stress. The receptors also respond to drugs used to modulate functions such as heart rate. Disregulation of these receptors and related signaling pathways is associated with congestive heart failure.
    Initially, Gregg studied the ability of the beta-3 receptor to regulate overstimulation to the heart. He applied to mouse blood vessels an enzyme solution that released individual heart cells that still functioned as if they were part of a whole organ. He then exposed the cells to fluorescent dyes that would reveal under a high-powered microscope the amount of calcium being released during each heart beat — a readout of the cells' response to stimuli. Next, he applied to the cells agents that either stimulate or inhibit specific proteins to disrupt signal pathways involved in contraction.
    Along the way, he found a pathway related to the beta-2 receptor whereby stimuli regulate the heart's ability to contract. The knowledge could eventually lead to better treatments for heart failure, Berkowitz says.
    Gregg presented his research results March 6 at the American College of Cardiology's annual meeting in Orlando, Fla., and is submitting a manuscript of his work to a peer-reviewed heart journal.
    "He has really become an integral member of our lab effort and has continued to inspire and train other students," Berkowitz says of Gregg.
    "It was a great overall experience," says Gregg. "I think I was really lucky, and I learned a lot." After graduating in May, Gregg plans to enter a doctoral research program.
    Gregg and Gupta also pursued other areas of interest while working in the lab. As a side project, Gregg wrote a software program that integrated his data in a new way to look at the relationship of calcium release and contraction length in heart cells. Ion Optix Corp., manufacturer of one of the instruments used in his study, is adapting the software for its own use. And Gupta's laboratory techniques to prepare blood vessels and examine their function helped cardiology faculty member Kaiko Irani complete his work characterizing the vascular appearance of a mouse deficient in a protein called redox-factor 1. For his efforts, Gupta was second author on a paper published in Circulation Research last year.
— Karen Blum



A ROLY-POLY SURPRISE: Katarina Juhaszova, working with Katalin Szlavecz, unearthed new findings about isopods.

Katarina Juhaszova is playing an important part in ascertaining the role that terrestrial isopods — bugs commonly known as pillbugs, sowbugs and roly-polys — play in the recycling of nutrients in forest ecosystems.
    Juhaszova's original research, focusing on the effect that several species of isopods have on soil nutrients, has been funded with support from a PURA.
    Knowing that isopods are not native to the mid-Atlantic region (they were brought to America during European colonization), Juhaszova wondered what effect — if any — the small creatures were having on the nutritional composition of forest soil, which, over time, can lead to changes in the forests' plant and animal composition.
    Working under the guidance of sponsor Katalin Szlavecz, professor in the Morton K. Blaustein Department of Earth and Planetary Sciences, Juhaszova ventured into local forests, where she studied the impact that six species of isopods had on the rate at which leaf litter, which provides food for the creatures, disappeared. In laboratory experiments, she also examined how the isopods' feeding activity alters the soil's organic content and nitrogen availability.
    What she learned surprised her.
    "We found that instead of depleting the nutrients in the soil, which is what has happened with some invasive species, the isopods actually are having the opposite effect," Juhaszova says. "Their droppings produce a good source of carbon for the microbes there, promoting their growth."
    Szlavecz calls her student's results "certainly interesting and worth investigating further."
    "We know that a sudden influx of non-native detritivores (creatures that eat leaf litter and other detritus) is likely to change the nutrient availability of forests over time, and not always for the better," Szlavecz says. "That's the case with earthworms; though they promote the decomposition of organic nitrogen, they do it at a rate that is so high that eventually nitrogen can be lost from the forests. What we are getting from Katy's research is that isopods have the opposite effect. Though it would be far-fetched and pompous for us to draw some big conclusions regarding the whole ecosystem level process based on Katy's data, it certainly is worth further scrutiny."
— Lisa De Nike



TESTING TISSUE ENGINEERING TECHNIQUE: Athar Malik supports Jennifer Elisseeff's efforts to repair cartilage and bone.

In a tissue engineering lab where researchers are making new materials to repair injured knees, noses and other body parts, senior Athar Malik is performing critical experiments to determine whether this promising technique is damaging cells.
    Malik, a biomedical engineering major, is conducting a study to determine if DNA in cells is being harmed by a chemical reaction that occurs during the tissue engineering process. His experiments in the laboratory of Jennifer Elisseeff, an assistant professor of biomedical engineering, have been supported by a PURA.
    Elisseeff has been guiding efforts to repair injured cartilage and bone without major surgery by injecting a liquid filled with cells that should promote the growth of healthy new tissue. When a special light is shone on it, this liquid hardens into a gel that holds the therapeutic cells in place. But before this material, called a photopolymerizable hydrogel, is used in humans, Elisseeff wants to be sure the chemical reaction used to harden the liquid is not damaging the helpful cells being injected into the body. "Our studies so far lead us to believe that the process is safe," Elisseeff says. "But we want to be as certain as possible. If we do find cell damage and can figure out how it occurs, we can try to correct the problems before moving forward."
    To look for signs of DNA damage to the treatment cells, Elisseeff turned to Malik, who has worked in her lab since his freshman year. He has contributed to the ongoing hydrogel research, receiving credit on three peer-reviewed journal papers, including one in which he was listed as a lead author. In a letter of support for Malik's PURA, Elisseeff cited his rapid progress in learning laboratory techniques, along with his "outstanding work ethic, dedication and intelligence."
    Malik says he had never taken part in formal lab research before arriving at Johns Hopkins. "One of the main reasons I joined this lab was to begin applying some of the things I'd learned in high school and in my classes here," he says.
    For his current project, Malik fills the chambers of a multiwell plate with a nutrient solution, then adds some of the adult goat stem cells that are being used in Elisseeff's injury repair project. After the cells have had time to thrive, Malik adds a photoinitiator, the chemical used to trigger the chemical reaction that hardens a hydrogel. He next exposes the wells to ultraviolet light for varying periods, setting off the chemical reaction.
    "Our goal is to see if this reaction has damaged the cells," Malik says.
    To find out, he extracts DNA strands from the cells and uses a lab test to determine their length. Shorter strands indicate they have been cut — a sign of damage. "If we see that the DNA has been damaged, we try to look at it in further detail to find out specifically what has caused the damage and what can be done to prevent it," he says.
    After finishing his analysis of the data, Malik hopes to publish his findings in yet another peer-reviewed journal article. "I feel very fortunate to have had the opportunity to work and have an active role in Professor Elisseeff's lab," Malik says. "When I first joined, she paired me with older members of the lab so that I could learn from their experience. Now, I'm helping some of the younger students."
    Outside the lab, Malik serves as president of Tau Beta Pi, the engineering honor society, and works as a residence hall adviser. Last year, he received an honorable mention in USA Today's All-USA Academic Team program. After graduation in May, he hopes to enter a rigorous M.D.-Ph.D. graduate program. "I would like to both practice medicine and conduct biomedical research," he says.
— Phil Sneiderman


The 12th Annual PURA Ceremony
Check out their results —

To recognize the recipients of the 2004 Provost's Undergraduate Research Awards, an event will be held from 3 to 6 p.m. on Thursday in Homewood's Glass Pavilion.

A poster session in which students will have an opportunity to display the results of their research begins at 3 p.m.

At the 4:30 p.m. recognition ceremony hosted by Steven Knapp, provost and senior vice president for academic affairs, Theodore Poehler, vice provost for research and chair of the selection committee, will introduce the honorees, and Provost Knapp will present the students' certificates. Also on the agenda is a presentation by junior Robert Whelan, whose summer research involved the music of the Shetland Isles. A reception will follow.

The entire Johns Hopkins community is invited.


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