1. Department of Physics, I.I.T. Bombay, Mumbai 400076, India
2. Systems Biology Doctoral Training Centre, University of Oxford, Oxford OX1 3QU, UK
3. School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, UK
4. Department of Physics and Astronomy, Durham University, Durham DH1 3LE, UK
5. Department of Mathematical Sciences, Durham University, Durham DH1 3LE, UK
6. The Isaac Newton Institute of Mathematical Sciences, University of Cambridge, Cambridge CB3 0EH, UK