1. Department of Anthropology; Oregon State University; Corvallis Oregon
2. Epidemiology Program, College of Public Health & Human Sciences; Oregon State University; Corvallis Oregon
3. Department of Family and Community Medicine and Department of Obstetrics and Gynecology; University of New Mexico School of Medicine; Albuquerque New Mexico
4. Division of Midwifery, Department of Family Practice; University of British Columbia; Vancouver British Columbia