Assertion: melatonin | /r/HasProperty | dark
Facets:
value: outdoors
type: LOCATION
value: outside
type: LOCATION
Source sentences:
text: It increases when it is dark outside (usually starting to increase 2 hours prior to bedtime) signaling the body that it is time to go to sleep.
text: In humans, melatonin is secreted into the blood from the pineal gland when it is dark.
text: Melatonin is a natural hormone produced by a gland in the brain at night (when it is dark outdoors).