1. Friends Research Institute, Inc., Los Angeles, California, USA.
2. Department of Public Health, Rongxiang Xu College of Health & Human Services, California State University, Los Angeles, Los Angeles, California, USA.
3. Department of Family Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA.
4. Center for HIV Identification, Prevention and Treatment Services, Department of Family Medicine, University of California, Los Angeles, Los Angeles, California, USA.