About the Authors

Jason D Barbour

To whom correspondence should be addressed. E-mail: jbarbour@php.ucsf.edu

Uma Sriram
Stacy J Caillier
Jay A Levy
Frederick M Hecht
Jorge R Oksenberg

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

JDB, JAL, FMH, and JRO designed the study. US, SJC, and JRO performed experiments. JDB analyzed the data. US, SJC, FMH, and JRO contributed reagents or tools. JDB, JAL, FMH, and JRO wrote the paper.