1. Departments of Preventive Medicine (M.L.C., G.B., M.I.G.), Los Angeles, California 90089
2. Department of Pediatrics (M.J.W.), Los Angeles County and University of Southern California Medical Center, Los Angeles, California 90033
3. Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging (T.T.-K.H.), Tufts University, Boston, Massachusetts 02111
4. Keck School of Medicine, Department of Biokinesiology and Physical Therapy (G.Q.S.), University of Southern California, Los Angeles, California 90089
5. Physiology and Biophysics (M.I.G.), Los Angeles, California 90089