1. Divisions of Epidemiology and Biostatistics, University of California, Berkeley School of Public Health, Berkeley, California.
2. Department of Global Health, Milken Institute School of Public Health, The George Washington University, Washington, District of Columbia.
3. Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts.
4. Public Health Institute, Oakland, California.
5. Institute for Research in Health and Nutrition, Universidad San Francisco de Quito, Quito, Ecuador.