Dr John Singleton, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, Tel: 01865 272236, Fax: 01865 272400, Email:
[email protected]. Leave of absence Aug 2000- Aug 2001: National High Magnetic Field Laboratory, Los Alamos National Laboratory, Mail Stop E536, Los Alamos, NM 87545, USA, Tel: +1 505 665 3857, Fax: +1 505 665 4311, Email:
[email protected]