1. The Prevention and Research Center, The Weinberg Center for Women's Health and Medicine, Mercy Medical Center, Baltimore, Maryland.
2. Department of Epidemiology and Public Health, University of Maryland, Baltimore, Maryland.
3. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
4. Johns Hopkins University School of Medicine, Baltimore, Maryland.
5. Department of Comparative Biosciences, University of Illinois, Urbana, Illinois.