1. Fraunhofer FIRST, Kekuléstraße 7, 12489 Berlin, Germany, Technische Universität Berlin, Department of Computer Science, Franklinstraße 28/29, 10587 Berlin, Germany, idalab GmbH, Sophienstraße 24, 10178 Berlin, Germany, and Research Laboratories of Bayer Schering Pharma, Müllerstraße 178, 13342 Berlin, Germany