1. Medical Physics Program, College of Medicine, University of Florida, Gainesville, FL
2. Department of Radiology, Johns Hopkins University, Baltimore, MD
3. Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokaimura, Japan
4. Department of Statistics, Radiation Effects Research Foundation, Hiroshima, Japan
5. Consultant, San Diego, CA
6. Nuclear Science Research Institute, Japan Atomic Energy Agency, Tokaimura, Japan
7. George W. Woodruff School of Mechanical Eng., Georgia Institute of Technology, Atlanta, GA
8. National Cancer Institute, National Institutes of Health, Rockville, MD
9. J. Crayton Pruitt Family Department of Biomedical Eng., University of Florida, Gainesville, FL USA.