1. Berkeley School of Public HealthUniversity of California Berkeley California USA
2. San Francisco School of Medicine, Epidemiology & BiostatisticsUniversity of California San Francisco California USA
3. Instituto Nacional de Salud Pública Cuernavaca Morelos Mexico
4. Center for Research in Mathematics (CIMAT) Aguascalientes Aguascalientes Mexico
5. Yale School of Public Health New Haven Connecticut USA