category c1 Refereed Journal Article pt.20/5/11. Not checked in Sherpa, 24/06/11 RD. White in Sherpa, Author's Pre-print: archiving status unclear, and Author's Post-print: subject to 12 months Restrictions (embargo), author can archive post-print (ie final draft post-refereeing), author cannot archive publisher's version/PDF. 03.11-11-MMM. Author initiated, author has sent Post-Print, Requested Permission, 17.12.13-MMM. Permission rec'd, 9.1.14-MMM. Supporting documentation added to dark upload - HD 30/5/18