area of research is aimed at understanding relationships to water resources in the United States and Mexico. That research includes risk perceptions of water-borne disease and ecosystem service protection. Over the years, she also has studied public participation and organizational change within the U.S. Department of Agriculture Forest Service. Dr. Halvorsen received her Ph.D. from the University of Washington.

Jason D. Hill is an assistant professor in the Department of Bioproducts and Biosystems Engineering at the University of Minnesota. His research interests include the technological, environmental, economic, and social aspects of sustainable bioenergy production from current and next-generation feedstocks. His work on the life-cycle impacts of transportation biofuels has been published in the journals Science and the Proceedings of the National Academy of Sciences of the United States of America. His current research focuses on the effects that the expanding global biofuel industry is having on climate change, land use, biodiversity, and human health. Dr. Hill has testified before U.S. Senate committees on the use of diverse prairie biomass for biofuel production and on the greenhouse-gas implications of ethanol and biodiesel. He has also performed independent analysis for the National Renewable Energy Laboratory, NRC, and the U.S. Environmental Protection Agency. Dr. Hill served on the NRC Steering Committee on Expanding Biofuel Production: Sustainability and Transition to Advanced Biofuels. Dr. Hill received his Ph.D. in plant biological sciences from the University of Minnesota.

Stephen R. Kaffka is director of the California Biomass Collaborative and extension specialist in the Department of Plant Sciences at the University of California, Davis. He is chair of the BioEnergy Work Group for the University of California’s Division of Agriculture and Natural Resources. From 2003 to 2007, he was director of the Long Term Research on Agricultural Systems Project, in which he led the development of current and new projects focusing on sustainable agriculture. His commodity assignments include sugar and oilseed crops. Since joining the university in 1992, he has also carried out research on water quality and agriculture in the Upper Klamath Basin, and the reuse of saline drainage water for crop, forage, energy biomass feedstocks, and livestock production in salt-affected areas of the San Joaquin Valley. He participates on several advisory committees for the California Energy Commission and California Air Resources Board, including the Bioenergy Interagency Work Group as an ex officio member. He has received meritorious service awards from the American Society of Sugar Beet Technologists and the Soil and Water Conservation Society. He is past president of the California chapter of the American Society of Agronomy and past section leader for the American Society of Agronomy’s division on environmental quality. He holds a Ph.D. in agronomy from Cornell University.

Kirk C. Klasing is a professor of animal nutrition in the Department of Animal Science at the University of California, Davis. His research into the impact of nutrition on immunochemistry and disease resistance encompasses three interrelated areas. He examines the impact of an immune response against infectious diseases on growth and reproduction. He is interested in identifying the cytokines and hormones that the immune system releases in order to direct nutritional resources towards defense instead of growth and reproduction. Dr. Klasing strives to quantify the nutritional costs of these immune defenses, and investigates the impact of an animal’s diet on the immune response. He also explores the diverse nutritional and immune strategies of carnivorous, nectarivorous, herbivorous, and granivorous animals. Dr. Klasing has served on several NRC committees, including the Committee on Minerals and Toxic Substances in Diets and Water for Animals as chair and