1. Harvard Medical School, Cambridge Health Alliance, Cambridge, MA, USA;
2. NSF International, Ann Arbor, MI, USA;
3. National Institute for Public Health and the Environment (RIVM), Health Protection Center, Bilthoven, The Netherlands;
4. United States Department of Defense, Consortium for Health and Military Performance, Uniformed Services University, Bethesda, MD, USA;
5. National Institute for Public Health and the Environment (RIVM), Health Protection Center, Bilthoven, The Netherlands