1. From the Robarts Research Institute (D.P.I.C., R.L.E., S.S., F.G., J.S.H.B., A.J.M., G.P.), Department of Medical Biophysics (D.P.I.C., R.L.E., G.P.), Graduate Program in Biomedical Engineering (F.G., J.S.H.B., A.J.M.), and Department of Medicine, Division of Respirology (D.G.M.), Western University, University of Western Ontario, 1151 Richmond St N, London, ON, Canada N6A 5B7; and Firestone Institute for Respiratory Health, McMaster University, Hamilton, ON, Canada (S.S., P.N., G.P.).