Department of Computer Science, Bioinformatics Group, Centre for Computational Statistics and Machine Learning, University College London, Malet Place, London WC1E 6BT, UK. d.jones@cs.ucl.ac.uk|Department of Computer Science, Bioinformatics Group, Centre for Computational Statistics and Machine Learning, University College London, Malet Place, London WC1E 6BT, UK. d.jones@cs.ucl.ac.uk|Department of Computer Science, Bioinformatics Group, Centre for Computational Statistics and Machine Learning, University College London, Malet Place, London WC1E 6BT, UK. d.jones@cs.ucl.ac.uk|Department of Computer Science, Bioinformatics Group, Centre for Computational Statistics and Machine Learning, University College London, Malet Place, London WC1E 6BT, UK. d.jones@cs.ucl.ac.uk