larry Are you looking for stuff like this. https://www.sciencedirect.com/science/article/pii/S2214574515000863 randy oliver posted this one to make a differrent point but if my memory is correct, it does make the case that there is usually more then one stressor involved in failure. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4601502/ Hope some of this gets you a bit closer to where you want to go. Good luck gww *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html