1. Swiss Federal Institute for Aquatic Science and Technology (EAWAG), Überlandstrasse 133, CH-8600 Dübendorf, Switzerland
2. The University of Bern, Bern, Switzerland
3. IBP, Swiss Federal Institute of Technology (ETH) Zürich, CH-8092 Zürich, Switzerland, and ENAC, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland