1. Departments of Medicine and Physiology; Hunter Holmes McGuire Department of Veterans Affairs Medical Center; Virginia Commonwealth University School of Medicine; Richmond VA USA
2. Department of Medicine; Division of Clinical Pharmacology; Autonomic Dysfunction Center; Vanderbilt University School of Medicine; Vanderbilt University; Nashville TN USA
3. Department of Kinesiology, Health, and Nutrition; University of Texas at San Antonio; San Antonio TX USA
4. Dartmouth Hitchcock Medical Centre; Lebanon NH USA
5. Department of Physiology; Pennsylvania State University; University Park and Hershey PA USA
6. Department of Physics; Turku University; Turku Finland
7. Department of Clinical Physiology and Nuclear Medicine; South Karelia Central Hospital; Lappeenranta Finland
8. Gifu University of Medical Science; 795-1 Nagamine Ichihiraga Seki Gifu 501-3892 Japan
9. Department of Physiology; Aichi Medical University; Aichi Japan
10. DLR-Institute for Aerospace Medicine; Cologne Germany
11. Department of Medicine; University of Texas Southwestern Medical Centre at Dallas; Dallas TX USA
12. Institute for Exercise and Environmental Medicine; Texas Health Presbyterian; Hospital; Dallas TX USA
13. University of Texas Southwestern; Dallas TX USA