1. University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco, California (S.K., J.I., B.E.C.)
2. Northern California Institute for Research and Education, San Francisco, California (S.S., M.V., C.D., S.R.Y.)
3. University of California, Davis, Davis, California (M.C.)
4. Columbia University, New York, New York (D.H.)