1. Research Chemist, Protein Nutrition Laboratory, ARS, USDA.
2. George Lynn Cross Research Professor, Departments of Pediatrics and Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center.
3. Professor and Vice Chairman, Department of Gynecology and Obstetrics, University of Oklahoma Health Sciences Center.
4. Assistant Professor, Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center.