1. From the University of Western Ontario (B.D.M., T.-Y.L.), London, ON; Robarts Research Institute (B.D.M., T.-Y.L.) London, ON; Lawson Health Research Institute (B.D.M., T.-Y.L.), London, ON; London Health Sciences Centre (D.H.L., I.B.G., V.B., D.P., V.H., R.C.), London, ON; Sunnybrook Health Sciences Centre (A.J.F., D.J.S., S.E.B., R.I.A., S.S.), Toronto, ON; Foothills Medical Centre (S.B.C., A.M.D.), Calgary, AB; and Ottawa Health Research Institute (M.J.H., M.G.), Ottawa, ON.