1. Institute of HygieneUniversity of Münster Robert-Koch-Str. 41 48149 Münster Germany
2. Interdisciplinary Center for Clinical Research (IZKF)University of Münster Domagkstr. 3 48149 Münster Germany
3. Institute of Medical Physics and BiophysicsUniversity of Münster Robert-Koch-Str. 31 48149 Münster Germany