1. From the Departments of Pediatrics (CLK), Medicine (CLK, KIC, and DBE), Medical Biostatistics (JYB), Rehabilitation and Movement Sciences (CLT), and Psychiatry (JAD), University of Vermont, Burlington, VT, and the Departments of Medicine and Pharmacology & Cancer Biology, Sarah W Stedman Nutrition and Metabolism Center, Duke University, Durham, NC (TRK and DMM).