1. Department of Chemistry, University of Oslo, Blindern, P.O.
Box 1033, Oslo N-0315, Norway
2. Laboratory of Neural Development and Optical Recording (NDEVOR), Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.
Box 1103, Oslo N-0317, Norway
3. Norwegian Center for Stem Cell Research, Oslo University Hospital, Oslo N-0317, Norway
4. Institute for Energy Technology, P.O. Box 40, Kjeller N-2027, Norway