. Author manuscript; available in PMC: 2015 Mar 26.
Published in final edited form as: J Theor Biol. 2014 Aug 23;363:247–261. doi: 10.1016/j.jtbi.2014.08.018
© 2014 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).