Institution: | a Department of Applied Mathematics, The University of Western Ontario, Middlesex College, 1151 Richmond St. N., London, Ont., Canada N6A 5B7 b Department of Physics, Brown University, Providence, RI 02912-1843, USA c COMP Center of Excellence and Department of Applied Physics, Helsinki University of Technology, P.O. Box 1100, FI-02015 TKK, Espoo, Finland d Institute of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland e MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, Denmark f Physics Department, Rutherford Building, McGill University, 3600 rue University, Montr´eal, Que., Canada H3A 2T8 |