Engineer, Three Other Faculty Members Receive Presidential Awards

July 13, 2002

A Duke engineer uses lightning discharges as tools to probe an under-studied region of Earth's atmosphere. A Duke chemist develops a better method to measure the stability of proteins. One Duke medical researcher studies the roles of two genes in molecular pathways that regulate the structural development of the head and face. A second works to improve the quality of life for dying patients.

All four Duke faculty were among 60 in the nation honored July 12 for their 2001 Presidential Early Career Awards for Scientists and Engineers (PECASE), a special recognition for young federally-funded investigators. Begun by President Clinton, the PECASE program provides additional recognition for a select group of researchers whose projects are deemed of greatest benefit to their funding agencies' missions.

Steven Cummer, an assistant professor of electrical and computer engineering at Duke's Pratt School of Engineering, received his PECASE in recognition of his ionosphere study proposal that received $414,000 in support from the National Science Foundation.

At an altitude between about 60 and 180 kilometers, or about 40 to 100 miles, the ionosphere is the region where air molecules become electrically charged. It also harbors the strangest manifestations of lower atmospheric weather: "sprites" and other ghostly, glowing phenomena that are linked to lightning discharges.

Cummer uses a radio receiver and antenna in Duke Forest to detect and analyze long-distance lightning discharges and associated sprites at extremely low radio frequencies that are "strongly reflected by the lower ionosphere," he said. Such detection ability makes lightning a natural probe into one of the least understood regions of the upper atmosphere, he added.

The lower ionosphere is a region too low to be studied by orbiting satellites, but too high for weather balloons, he said. The military has built gigantic low frequency radio transmitters and antennae for communications purposes that can bounce these waves off the ionosphere. But for scientific studies, scientists have mostly used rocket probes that are very localized in space and time, he said.

"But lightning is perfect because it radiates strongly at exactly the right frequencies," said Cummer. "So during a period when there are 10 different storms over the U.S. at one time, which is pretty common during the summer in particular, we can probe the ionosphere along every single one of those paths between the source and the receiver to answer important questions about the variability of the upper atmosphere."

Michael Fitzgerald, an assistant professor of chemistry, will receive a PECASE for developing and applying a quicker and more sensitive method for measuring the thermodynamic stability of proteins in their "folded" forms.

Proteins fold within their natural watery environments from stringlike molecules into complex three-dimensional shapes that enable them to do their jobs as biological catalysts and structural molecules. "They're constantly folding and unfolding, but the large majority of proteins need to be in their folded state to perform their biological function," Fitzgerald said.

"Stability measurements are a very important research tool when you're trying to understand how proteins fold," he added. And the traditional measurement methods involve time-consuming optical detection techniques that require large amounts of highly purified protein.

Fitzgerald's approach, funded by $530,000 from the National Science Foundation, uses a technique called mass spectrometry to accurately record the molecular weight of proteins under specific conditions that ultimately permit their stability to be measured.

With the new method, "we should be able to make measurements in minutes compared to hours," he said. "You only have to have very small quantities of protein. And it doesn't have to be highly purified." The analytical technique was developed in collaboration with the laboratory of Terry Oas, an associate professor of biochemistry.

John Klingensmith, an assistant professor of cell biology, was cited for his basic research in developmental biology that is contributing to the understanding of birth defects, primarily those involving the head and face. His work could lead to gene testing and therapy to prevent birth defects or possibly to new treatments for birth defects.

A developmental geneticist who specializes in the emergence of craniofacial and neural tube defects during gestation, his research in mice has led to the identification of two genes, called Chordin and Noggin, that play critical role in that emergence.

The award stems from a $1.7 million National Institutes of Health grant focusing on those two genes, which are known to regulate Bone Morphogenic Proteins (BMPs). BMPs are a family of protein signals that have potent effects on craniofacial development. BMP2 and BMP4 are thought to be particularly important in the growth of the brain, skull, pituitary gland, teeth and face. Scientists had not previously made the connection between BMP regulation and neural tube defects.

"Our primary goal is to understand the mechanisms of human birth defects," he said. "In our work on BMP signaling, I think we've made an important contribution toward explaining the mechanism of how birth defects of the head and the face occur.

"Very little is known about the molecular and genetic mechanisms that underlie these birth defects, or for that matter, normal craniofacial development. Much of our research is designed to reveal the key steps in head formation, and to elucidate the molecular basis of craniofacial birth defects."

James Tulsky, M.D., a general internist at the Durham Veterans Affairs (VA) Medical Center with a joint appointment as associate professor of medicine at the Duke University Medical Center, was nominated for a PECASE by the Department of Veteran Affairs for his research that explores the quality of life at the end of life.

The research, which was funded by two grants from the VA totaling $550,000, is designed to define the attributes of a "good" death -- one that eases the transition for the patient -- and to create a method to measure the quality of life for dying patients.

At the Durham VA Medical Center, he directs the Program on the Medical Encounter and Palliative Care. At the Duke Medical Center, he is a physician in ambulatory care and associate director of the Duke Institute on Care at the End of Life.

Tulsky and colleagues identified six possible interventions designed to improve its quality of life at the end of life -- pain and symptom management, clear decision making, preparation for death, completion, contributing to others and affirmation of the whole person.

His research has shown there is no one definition of "a good death" and that wide disagreement exists about the importance of such issues as dying at home and the use of life-sustaining treatments, Tulsky said.