[1] Univ Manchester, Sch Biol Sci, Manchester M13 9PT, Lancs, England
[2] UMIST, Michael Barber Ctr Mass Spectrometry, Dept Chem, Manchester M60 1QD, Lancs, England
[3] Univ Aberdeen, Inst Med Sci, Aberdeen AB25 2ZD, Scotland
[4] Univ Exeter, Sch Biol Sci, Washington Singer Labs, Exeter EX4 4QG, Devon, England
[5] Univ Manchester, Dept Comp Sci, Manchester M13 9PL, Lancs, England