1. National Institutes of Health; National Center for Complementary and Integrative Health; 10 Center Drive Bethesda MD USA 20892
2. National Institutes of Health; National Institute of Nursing Research; 10 Center Drive Bethesda MD USA 20892
3. University of Duisburg-Essen; Department of Internal and Integrative Medicine, Kliniken Essen-Mitte, Faculty of Medicine; Am Deimelsberg 34 a Essen Germany D-45276
4. University of Würzburg; Department of Neurology; Würzburg Germany 97080
5. University of Oxford; Pain Research and Nuffield Department of Clinical Neurosciences (Nuffield Division of Anaesthetics); Churchill Hospital Oxford UK OX3 7LJ
6. Technische Universität München; Department of Psychosomatic Medicine and Psychotherapy; Langerstr. 3 München Germany D-81675