Conversely, having an extra 'strong' circadian cycle
would probably not be good.
Crew endurance is comprised of both physiological and psychological factors including quality and duration of sleep, the circadian cycle
, the emotional state, environmental stressors, diet and physical conditioning (U.
As expected, the captive colony of Jamaican fruit bats exhibited a reverse-patterned circadian cycle
complementary to the reverse-daylight pattern utilized in the Jamaican fruit bat exhibit.
People operating with a sleep debt are less efficient, and this inefficiency is most noticeable when the circadian cycle
is at its lowest ebb.
The body's circadian cycle
is a 24-hour cycle which controls functions such as body temperature, digestion and respiration and induces us to fall asleep at night and stay awake during daylight hours.
First, it may require crew members to be on duty during the part of the circadian cycle
when their performance capacity and alertness are lowest.
This difference in responses can be represented by a phase-response curve (see figure 1 for a schematic illustration of a circadian cycle
as well as a phase-response curve).
This 24-hour light-dark circadian cycle
is derived from the Latin circa ("about") and dies ("dies").
A small diurnal increment in blood pressure occurred in both groups particularly on the second day of the circadian cycle
(Figure 2), and in both there was a nocturnal fall in systolic blood pressure.
Like everyone else, sleep-deprived people are likely to function best in the mid-morning and early evening, typically the high points of the circadian cycle
The same amounts of food eaten at different times during the circadian cycle
will have different effects.
Research team members hypothesize that periods of blue light, like daylight, can help regulate the sleep-wake rhythm, which is a behavioral pattern linked to the 24-hour biochemical circadian cycle
of the hormone melatonin.