1. Mathematics Institute, University of Warwick, Coventry, UK
2. School of Life Sciences, University of Warwick, Coventry, UK
3. Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research, University of Warwick, Coventry, UK
4. Institute of Applied Statistics, Johannes Kepler Universität, Linz, Austria
5. Department of Statistics, University of Warwick, Coventry, UK