1. Red Blood Cell Group, Institute of Veterinary Physiology, University of Zurich, 8057 Zurich, Switzerland
2. Theoretical Medicine and Biosciences, Campus of Saarland University Hospital, Saarland University, 66424 Homburg, Germany
3. Dynamics of Fluids, Experimental Physics, Saarland University, 66123 Saarbrücken, Germany