[1] UCL, Dept Phys & Astron, London, England
[2] UCL, Inst Phys Living Syst, London, England
[3] Northeastern Univ, Dept Phys, Boston, MA 02115 USA
[4] Yale Univ, Dept Biomed Engn, New Haven, CT USA
[5] Yale Univ, Syst Biol Inst, West Haven, CT USA
[6] Yale Univ, Dept Phys, New Haven, CT USA