1. Grand Forks Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, P.O. Box 9034, Grand Forks, North Dakota 58203-9034; Department of Experimental Pathology, Roswell Park Cancer Institute, Buffalo, New York 14263-0001; Department of Fruit and Vegetable Science, Cornell University, Ithaca, New York 14853; Department of Animal and Range Science, North Dakota State University, Fargo, North Dakota 58105; and Department of Environmental and Molecular Toxicology, Oregon...