1. Department of Medicine, Morehouse School of Medicine, Atlanta, GA
2. University of Pittsburgh School of Medicine, Pittsburgh, PA
3. Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco CA
4. Research Institute, California Pacific Medical Center, San Francisco, CA
5. Department of Aging and Geriatric Research, College of Medicine, University of Florida, Gainesville, FL
6. Department of Preventive Medicine, University of Tennessee, Memphis, TN
7. Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Bethesda, MD