Received: 4 October 2019
Accepted: 31 January 2020
First Online: 10 February 2020
Ethics approval and consent to participate
: This study was reviewed and certified exempt from human subject’s protection procedures by the University of California, San Francisco Committee on Human Research (CHR) (# 15–15698). Participants received written information about the study, gave verbal consent and signed informed consent for photography. Verbal consent was deemed sufficient by CHR as the study met the federal regulations in 45 CFR 46.104 (Common Rule, category 2) of a minimal risk research and therefore was exempt from federal policy for the protection of human subjects.
: Not applicable.