Distinguished Professor, ACADEMIC APPOINTMENTS AND PROFESSIONAL EXPERIENCE: Research Assistant, Oxford University, 1966; Research Associate, Harvard University, 1967; Associate Research Officer, National Research Council of Canada, 1968-73; Associate Professor, University of Guelph, Canada, 1973-77; Professor, University of Guelph, Canada, 1977-81; Distinguished Professor, Veterinary Physiology & Pharmacology, Texas A&M University, 1981-present; Chester J. Reed Chair in Toxicology, 1983; Senior Scientist, Institute of Occupational & Environmental Medicine, Texas A&M University. 1983-present; Distinguished Professor, Texas A&M University, 1984-Present; Adjunct Professor, University of Guelph, 1985-Present; Sid Kyle Chair in Toxicology, Texas A&M University, 1992; Director, Center for Environmental and Genetic Medicine, institute of Biosciences & Technology Texas A&M Health Science Center, 2002-present.