About the Authors

Lucy J. Colwell, Michael P. Brenner
School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts, United States of America

Corresponding Author

lcolwell@fas.harvard.edu

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Analyzed the data: LJC MPB. Wrote the paper: LJC MPB. Conceived and designed the calculations: LJC MPB.