1. Department of Mathematics, Imperial College London, London, SW7 2AZ, UK; MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK; Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics and Department of Computer Science, Freie Universität Berlin, Berlin, 14195, Germany ().
2. Department of Mathematics, Imperial College London, London, SW7 2AZ, UK ().
3. Department of Computer Science, RWTH Aachen University, Aachen, 52074, Germany ().