CNMS USER RESEARCH

Fluctuations and Correlations in Physical and Biological Nanosystems

Michael L. Simpson and Peter T. Cummings
Center for Nanophase Materials Science, Oak Ridge National Laboratory

When components at one level (atoms, molecules, nanostructures, etc) are coupled together to form higher-level — mesoscale — structures, new collective phenomena emerge. Optimizing such systems requires embracing stochastic fluctuations in a manner similar to that found in nature. E.g., homeostasis - regulation of a cell’s internal environment to maintain stability and function at the mesoscale (i.e., cell) in the face of an unpredictable environment - is maintained even though there is considerable noise at the nanoscale (protein, RNA, molecular motor). A recent ACS Nano Perspective paper1 describes the CNMS theme research vision that focuses on understanding how ‘nanoscale noise’ is used by biology to enable ‘mesoscale stability’.

An intriguing hypothesis of the paper is the existence of a ‘conservation of stochasticity’ at the mesoscale, which asserts that noise cannot be avoided, but may be distributed unequally among the components in a way that enables adaptive responses to unpredictable external perturbations. An example taken from a recent CNMS publication2 illustrates this unequal distribution by showing that noise in yeast is preferentially distributed to a class of proteins that specifically respond to environmental fluctuations, suggesting that fluctuations in nanoscale components enable a mesoscale response to unpredictable external fluctuations. The vision of the CNMS theme research is to use such biological lessons to realize synthetic mesoscale systems.

Credit:

This research was supported by the Center for Nanophase Materials Sciences at the Oak Ridge National Laboratory, by the Office of Basic Energy Sciences, U. S. Department of Energy. The research was published as a Perspective paper as Simpson, M. L., and P. T. Cummings (2011), “Fluctuations and Correlations in Physical and Biological Nanosystems: The Tale Is in the Tails,” ACS Nano, 5(4), April 2011. DOI: 10.1021/nn201011m


  1. Simpson, M. L., and P. T. Cummings (2011), “Fluctuations and Correlations in Physical and Biological Nanosystems: The Tale Is in the Tails,” ACS Nano, 5(4), April 2011.
  2. Dar, R. D., D. K. Karig, J. F. Cooke, C. D. Cox, and M. L. Simpson (2010), “Distribution and regulation of stochasticity and plasticity in Saccharomyces cerevisiae,” Chaos 20, 037106-1-8.