http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371% 2Fjournal.pcbi.1000216 When Noam Kaplan was in Leuven, he mentioned they were having difficulty getting their paper in one of the Nature journals. I wonder if this is that paper? Tom -- Tom Michoel <http://www.psb.ugent.be/~tomic/>