1. MedStar Research Institute, Baltimore, MD;
2. Clinical Research Branch, National Institute on Aging, Baltimore, MD;
3. Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine and
4. Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD;
5. Columbia University Joseph L. Mailman School of Public Health, Columbia University, New York, NY;
6. Laboratory of Neurogenetics and
7. Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, MD;
8. Center for Statistical Genetics, Department of Biostatistics, University of Michigan, Ann Arbor; and
9. Geriatric Unit, Azienda Sanitaria Firenze, Florence, Italy