1. Department of Nutrition, University of California, Davis, Davis, CA
2. Biological Chemistry, School of Medicine, University of California, Davis, Davis, CA
3. Gastroenterology Unit, Women's and Children's Hospital, North Adelaide, SA, Australia
4. Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA
5. R. G. D. Research, Inc., Niskayuna, New York
6. Nutritional & Health-Related Environmental Studies Section International Atomic Energy Agency, Vienna, Austria