About the Authors

Katy Ashe

kashe@stanford.edu

Affiliation Department of Civil and Environmental Engineering, Stanford University, Stanford, California, United States of America

Competing Interests

The author has declared that no competing interests exist.

Author Contributions

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