1 Division of Pulmonary Medicine, Department of Medicine, Faculty of Medicine and Dentistry,University of Alberta, Edmonton, Alberta, Canada.
2 Neurovascular Research Laboratory, School of Kinesiology,Western University, London, Ontario, Canada.
3 Institute for Exercise and Environmental Medicine, Health Presbyterian Hospital Dallas, Dallas, Texas.
4 Internal Medicine,The University of Texas Southwestern Medical Center, Dallas, Texas.
5 Cardiovascular Health and Autonomic Regulation Laboratory, Department of Kinesiology and Physical EducationMcGill University, Montreal, Quebec, Canada.
6 Department of Physiology and PharmacologyWestern University, London, Ontario, Canada.