Assertion: melatonin's level | /r/CapableOf | signal the body
Facets:
value: gradually
type: MANNER
value: to begin falling asleep
type: PURPOSE
Source sentences:
text: When the sun rises, melatonin levels lessen to signal the body that it is time to awaken .
text: When the sun goes down, melatonin levels begin to rise and gradually signal to the body to begin falling asleep.
text: Levels of melatonin are higher at night, signaling the body that it is time to rest.