1. From the Bruno Balke Biodynamics Laboratory, Department of Kinesiology, University of Wisconsin-Madison (J.N.B., K.B.M.); and Department of Anesthesiology (J.N.B., K.R.M., M.J.J.), College of Medicine and Science (R.E.H.), Department of Physiology and Biomedical Engineering (M.J., V.M.M.), Heath Science Research, Division of Epidemiology and Biostatistics (B.D.L., K.R.B.), and Department of Surgery (V.M.M.), Mayo Clinic, Rochester, MN.