1. SISSA (Scuola Internazionale Superiore di Studi Avanzati), via Bonomea 265, 34136 Trieste, Italy
2. Weibel Scientific A/S, 3450 Allerød, Denmark
3. Matematica, Università di Trieste, Via A. Valerio 12/1, 34127 Trieste, Italy
4. Institute for Geometry and Physics (IGAP), Trieste, Italy
5. INFN, Sezione di Trieste, Trieste, Italy
6. Norwegian University of Science and Technology, Department of Mathematical Sciences, Trondheim, Norway