Division for Simulation of Biological Systems, WSI/ZBIT, Eberhard Karls University Tübingen Sand 14, D-72076 Tübingen, Germany. hoeglund@informatik.uni-guebingen.de|Division for Simulation of Biological Systems, WSI/ZBIT, Eberhard Karls University Tübingen Sand 14, D-72076 Tübingen, Germany. hoeglund@informatik.uni-guebingen.de|Division for Simulation of Biological Systems, WSI/ZBIT, Eberhard Karls University Tübingen Sand 14, D-72076 Tübingen, Germany. hoeglund@informatik.uni-guebingen.de|Division for Simulation of Biological Systems, WSI/ZBIT, Eberhard Karls University Tübingen Sand 14, D-72076 Tübingen, Germany. hoeglund@informatik.uni-guebingen.de|Division for Simulation of Biological Systems, WSI/ZBIT, Eberhard Karls University Tübingen Sand 14, D-72076 Tübingen, Germany. hoeglund@informatik.uni-guebingen.de