1. Department of Anthropology, University of Michigan, Ann Arbor, Michigan;
2. Departments of Anthropology and Health/Behavioral Sciences, University of Colorado Denver, Denver, Colorado;
3. Department of Medicine, University of Colorado Denver, Aurora, Colorado;
4. Department of Biology, Western State Colorado University, Gunnison, Colorado;
5. Instituto Boliviano de Biología de Altura, La Paz, Bolivia;
6. Altitude Research Center, Department of Emergency Medicine, University of Colorado Denver, Aurora, Colorado;
7. Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania; and
8. Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, Colorado