[1] Univ Leicester, Sch Comp & Math Sci, Leicester, Leics, England
[2] Univ Kent, Sch Comp, Canterbury, Kent, England
[3] Univ Chinese Acad Sci, Inst Comp Technol, Beijing, Peoples R China
[4] West Virginia Univ, Dept Chem & Biomed Engn, Morgantown, WV 26506 USA
[5] West Virginia Univ, Rockefeller Neurosci Inst, Morgantown, WV 26506 USA
[6] Univ Leeds, Sch Comp, Leeds, W Yorkshire, England