1. Medical Chronobiology Laboratory, University of South Carolina, Columbia, South Carolina, USA.
2. Cancer Prevention and Control Program, Department of Epidemiology and Biostatistics, School of Public Health, University of South Carolina, Columbia, South Carolina, USA.
3. The Rhythmomtery Laboratory, College of Biological Sciences, University of Minnesota, St. Paul, Minnesota, USA.
4. Department of Physiology, Leiden University, Leiden, the Netherlands.
5. Leiden Cytology and Pathology Laboratory, Leiden, the Netherlands.