Dr. Ann Aschengrau received her doctorate in epidemiology from Harvard School of Public Health in 1987 and joined the faculty of Boston University School of Public Health shortly thereafter. She is currently Professor of Epidemiology and Director of the Master of Science Degree Program in Epidemiology. For the past 15 years, she has taught introductory epidemiology to masters level students. Her research focuses on the environmental determinants of disease, including childhood lead poisoning, cancer, and disorders of reproduction and child development Dr. George R. Seage, III received his doctorate from Boston University School of Public Health in 1992. For over a decade, he served as the AIDS epidemiologist for the city of Boston and as a faculty member at Boston University School of Public Health. For 7 years he directed the U.S. HIV Prevention Trials Network. He is currently Associate Professor of Epidemiology at Harvard School of Public Health, and Director of the Interdisciplinary Concentration in Infectious Disease Epidemiology. For the past 13 years, he has taught courses in HIV epidemiology to masters and doctoral students. His research has focused on the biological and behavioral determinants of HIV-1 transmission and their application to HIV-1 prevention trials, particularly those involving vaccines and microbicidal agentsAschengrau, Ann is the author of 'Essentials of Epidemiology in Public Health', published 2003 under ISBN 9780763725372 and ISBN 0763725374.