This article is not available on Brunel University Research Archive in its post-print (final draft version) until June 2008.

If you wish to obtain a copy of the paper please contact Dr Thomas Owens at Thomas.Owens@brunel.ac.uk


Publisher:  	Oxford University Press
Pre-print:	tick   author can archive pre-print (ie pre-refereeing)
Post-print:	tick   subject to Restrictions below, author can archive post-print (ie final draft post-refereeing)
Restrictions:	

    * 12 month embargo on science, technology, medicine articles
    * 24 month embargo on arts and humanities articles