About the Authors

Steve E. Bellan

sbellan@berkeley.edu

Affiliation Department of Environmental Science, Policy and Management, University of California, Berkeley, California, United States of America

Competing Interests

The author has declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: SEB. Performed the experiments: SEB. Analyzed the data: SEB. Contributed reagents/materials/analysis tools: SEB. Wrote the paper: SEB.