1. Department of Epidemiology; University of Alabama at Birmingham; Birmingham Alabama 35294
2. Section on Statistical Genetics, Department of Biostatistics; University of Alabama at Birmingham; Birmingham Alabama 35294
3. Department of Pediatrics; University of Colorado Anschutz Medical Campus; Aurora Colorado 80045
4. Epidemiology and Biostatistics Division, Mel and Enid Zuckerman College of Public Health; University of Arizona; Tucson Arizona 85724
5. Departments of Nutrition and Molecular Biosciences; University of California at Davis; Davis California 95616
6. Center for Alaska Native Health Research; Institute of Arctic Biology; University of Alaska at Fairbanks; Fairbanks Alaska 99775