1. Department of Social and Behavioral Sciences University of California, San Francisco San Francisco CA USA
2. Center for Research on Environment, Health & Population Activities Kathmandu Nepal
3. Department of Prevention and Community Health George Washington University Washington DC USA
4. Department of Health, Behavior and Society, Bloomberg School of Public Health Johns Hopkins University Baltimore MD USA
5. Department of Epidemiology and Biostatistics University of California, San Francisco San Francisco CA USA