This seems to be my week to finally "de-lurk" around here. I did a collaboration a few years back on this; it's a fascinating topic. If you're curious to learn

This seems to be my week to finally "de-lurk" around here. I did a collaboration a few years back on this; it's a fascinating topic. If you're curious to learn more and have access, check out: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WM0-4DVBH3Y-1&_user=10&_coverDate=04%2F30%2F2006&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1428132340&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b715da28a8ab603d2c951da1a5de90a1 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi... I'll see if I can dig up a summary but am on iPhone at the moment.