1. University of Potsdam, Potsdam, Germany
2. Harvard University, Cambridge, Massachusetts, USA
3. Martin-Luther University Halle-Wittenberg, Halle, Germany
4. University of Gothenburg, Gothenburg, Sweden
5. University of Padova, Padova, Italy
6. National and Kapodistrian University of Athens, Athens, Greece
7. Norwegian Institute of Public Health, Oslo Norway
8. Wheaton College, Norton, Massachusetts, USA
9. University of Minnesota, Minneapolis, Minnesota, USA