About the Authors

Jennifer C. Duke

jduke@rti.org

Affiliation RTI International, Research Triangle Park, NC, United States of America

Tesfa N. Alexander

Affiliation Center for Tobacco Products, U.S. Food and Drug Administration, Silver Spring, MD, United States of America

Xiaoquan Zhao

Affiliations Center for Tobacco Products, U.S. Food and Drug Administration, Silver Spring, MD, United States of America, Department of Communication, George Mason University, Fairfax, VA, United States of America

Janine C. Delahanty

Affiliation Center for Tobacco Products, U.S. Food and Drug Administration, Silver Spring, MD, United States of America

Jane A. Allen

Affiliation RTI International, Research Triangle Park, NC, United States of America

Anna J. MacMonegle

Affiliation RTI International, Research Triangle Park, NC, United States of America

Matthew C. Farrelly

Affiliation RTI International, Research Triangle Park, NC, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: J. Duke JAA MCF. Performed the experiments: J. Duke JAA MCF. Analyzed the data: J. Duke AJM. Wrote the paper: J. Duke TNA XZ J. Delahanty JAA AJM MCF.