1. Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, North Carolina
2. Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
3. Department of Genetics, Washington University School of Medicine in St Louis, St Louis, Missouri
4. Department of Epidemiology, University of Southern Denmark, Odense, Denmark
5. Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
6. Department of Genetics, Washington University in St Louis, St Louis, Missouri
7. University of Washington, Seattle, Washington
8. Medical Center, Boston University, Boston, Massachusetts
9. Department of Sociology, University of Pennsylvania, Philadelphia, Pennsylvania