Title: Identifying sources variation and the flow of information in biochemical networks Authors: Clive G. Bowsher and Peter S. Swain Abstract: Stochasticity is present in most biological systems. In order to make a good assessment of their environment, cells need to clearly distinguish information from noise. A recent paper by Bowsher and Swain provides a mathematical description of how different sources of variation in the biological inputs affect the output. This decomposition of variance offers some guidelines on how to design experiments that can successfully measure each component. Bowsher and Swain also use the concept of "inverse ecology" in order to estimate what input distribution optimizes the informational content of the signal, therefore determining what the system might expect from its environment. Link: http://www.pnas.org/content/early/2012/04/20/1119407109.abstract