Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The experimental protocol. Horizontal bars indicate experimental light conditions; gray, black, and white represent dim (<50 lx), dark (0 lx), and bright (>5000 lx) lights, respectively. Arrows indicate the times of data collection; gray and white arrows indicate saliva and urine collection times, respectively. Gray triangles show the times of meals
