1. Cardiovascular and Mass Spectrometry Laboratories, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA (J.R.-M., J.G., G.G.D., A.H.L., N.R.M.).
2. Integrative Pharmacology and Systems Neuroscience Research Group, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain (J.R.-M.).