1. Department of Public Health, San Diego State University, Joint Doctoral Program in Public Health, San Diego, California, USA.
2. Department of Pediatrics, University of California, San Diego, La Jolla, California, USA.
3. Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, California, USA.
4. School of Public Health, San Diego State University, San Diego, California, USA.
5. Department of Psychology, San Diego State University, San Diego, California, USA.
6. Division of Preventive Medicine, University of California San Diego, La Jolla, California, USA.