1. Department of International Health, Rollins School of Public Health of Emory University, 1518 Clifton Road NE, Atlanta, Georgia 30322
2. Department of Environmental and Industrial Health, University of Michigan School of Public Health, 109 Observatory Street, M1530 SPH I, Ann Arbor, Michigan 48109-2029
3. Department of Anthropology, University of Michigan, 300 North Ingalls, North Ingalls Building, 10th Level, Ann Arbor, Michigan 48109-0406
4. Department of Biostatistics, Rollins School of Public Health of Emory University, 1518 Clifton Road NE, Atlanta, Georgia 30322