Department of Biology, School of Medicine, University of Patras, 26505, Rio, Patras, Greece, Institut für Automatik, ETH Zürich, 8092 Zürich, Switzerland and INRIA Grenoble-Rhône-Alpes, Montbonnot, 38334 Saint-Ismier Cedex, France Department of Biology, School of Medicine, University of Patras, 26505, Rio, Patras, Greece, Institut für Automatik, ETH Zürich, 8092 Zürich, Switzerland and INRIA Grenoble-Rhône-Alpes, Montbonnot, 38334 Saint-Ismier Cedex, France.