In the 1990s, Jeffrey M. Friedman, M.D., Ph.D., director of the Starr Center for Human Genetics at Rockefeller University, wondered why humans tend to keep their weight stable over years. “There must be some biological system that counts our calories for us,” said Friedman during his keynote speech at Student Research Day in May. His questioning led him to leptin, a hormone secreted in the blood that regulates food intake and energy expenditures. But food intake remains a complex process that is not completely understood. “We don’t know how this information is processed. We don’t know where it is processed.”

In patients who are deficient in leptin, he said, there is no signal to the hypothalamus that the body has adequate stores of fat. “This is a major medical problem,” Friedman said. “For reasons we don’t understand, obesity increases the risk for a host of diseases.”

Sixty-six students presented posters of their research and five students gave oral presentations of their award-winning theses: Jennifer Greenwold discussed doctors who wrote about the early days of the AIDS pandemic; Lauren Kernochan studied a gene linked to spinal muscular atrophy; Khoonyen Tay studied ways to reduce the overuse of antibiotics; Connor Telles investigated a potassium channel in the shark rectal gland; and Jaehyuk Choi described HIV replication in certain cells.