1. Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
2. Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska, USA
3. Biostatistics and Computational Biology Branch, NIEHS, Research Triangle Park, North Carolina, USA
4. Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, Maryland, USA