1. Department of Behavioral Sciences and Health Education, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
2. Center for AIDS Research, Emory University, GA 30322, Atlanta, USA
3. College of Public Health, University of Kentucky, Lexington, KY 40536-0003, USA
4. Department of Psychiatry, Brown University, Providence, RI 02912, USA
5. Department of Psychology, University of Illinois at Chicago, Chicago, IL 60607, USA