1. From the Boston University School of Medicine (R.A.S., M.L.A., N.G.F., J.J.), Boston University School of Public Health (Y.T., B.M.), Brigham and Women’s Hospital (M.E.S.), Harvard Medical School (M.E.S.), and the Veterans Affairs Boston Healthcare System (M.E.S.) — all in Boston; Mayo Clinic Arizona, Scottsdale (C.H.A., D.W.D.), Banner Alzheimer’s Institute, Phoenix (K.C., J.L., D.D.G., E.M.R.), and Arizona State University, Tempe (D.M.) — all in Arizona; and Avid Radiopharmaceuticals, Philadelphia (M.N...