1. Bartlett School of ArchitectureUniversity College London London WC1E 6BT UK
2. Department of Biochemical EngineeringBernard Katz BuildingUniversity College London London WC1H 0AH UK
3. Institute of Structural and Molecular BiologyUniversity College London London WC1E 6BT UK
4. M. Alexander 19 Athens 15773 Greece