text: AJA and MJR gratefully acknowledge RCUK and EPSRC, respectively, for ﬁnancial support. We 
  
  acknowledge support by the European Union via the FP6 and FP7 Marie Curie schemes [Grants 
  
  MRTN-CT-2004005728 (PATTERNS) and PITN-GA-2008-214919 (MULTIFLOW)]. 