1. Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences University of British Columbia Okanagan Kelowna BC V1V 1V7 Canada
2. Department of Anesthesiology, Pharmacology, and Therapeutics Vancouver General Hospital 899 West 12th Avenue Vancouver BC V5Z 1M9 Canada
3. Neurovascular Research Laboratory, Faculty of Life Sciences and Education University of South Wales Pontypridd CF37 4BB UK
4. Department of Physiology, Faculty of Medical & Health Sciences University of Auckland Park Road Grafton Auckland 1142 New Zealand
5. School of Human Sciences (Exercise and Sport Sciences) The University of Western Australia Nedlands Western Australia 6009 Australia
6. Division of Critical Care Medicine, Department of Medicine, Vancouver General Hospital, West 12th Avenue University of British Columbia Vancouver BC V5Z 1M9 Canada
7. Human Pharmacology & Physiology Lab, Department of Anesthesiology Duke University Medical Center Durham NC 27708 USA