1. Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (P.F.-M., D.L.R., J.J., J.T.).
2. Laboratory of Autonomic Regulation of the Cardiovascular System, Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia (E.L.).
3. Chair of Aerospace Medicine, University of Cologne, Germany (J.J.).
4. Institute of Clinical Chemistry, Hannover Medical School, Germany (R.L.).
5. SK3/Biomedical Research and Environmental Sciences Division, Human Health and Performance Directorate, National Aeronautics and Space Administration Johnson Space Center, Houston, TX (S.M.S.).
6. Department of Nutrition and Food Science, University of Bonn, Germany (M.H.).