1 From the Department of Biomedical Sciences, University of Minnesota Medical School Duluth (J.S.G., J.F.R.); and Department of Human Physiology, University of Oregon, Eugene (J.S.G., H.E.G.). jgilbert@d.umn.edu.
2 From the Department of Biomedical Sciences, University of Minnesota Medical School Duluth (J.S.G., J.F.R.); and Department of Human Physiology, University of Oregon, Eugene (J.S.G., H.E.G.).