1. Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Schuster Building, Oxford Road, Manchester M13 9PL, U.K.
2. Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
3. Unilever Research
and Development Port Sunlight Laboratory, Quarry Road East, Bebington, Wirral CH63 3JW, U.K.
4. STFC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K.