1. Health and Kinesiology; University of Texas at San Antonio; San Antonio; TX; USA
2. Department of Medicine; Division of Clinical Pharmacology; Autonomic Dysfunction Center; Vanderbilt University; Nashville; TN; USA
3. Internal Medicine; University of Texas Southwestern Medical Center at Dallas; Dallas; TX; USA
4. The Pennsylvania State University; University Park and Hershey; PA; USA
5. Dartmouth Hitchcock Medical Center; Lebanon; NH; USA
6. DLR-Institute for Aerospace Medicine; Cologne; Germany
7. Department of Physics; Turku University; Turku; Finland
8. Department of Clinical Physiology and Nuclear Medicine; South Karelia Central Hospital; Lappeenranta; Finland