Mammalian circadian rhythms are controlled by endogenous biological oscillators, including
a master clock located in the hypothalamic suprachiasmatic nuclei (SCN). Since the period …

Sleep deprivation among adolescents is epidemic. We argue that this sleep deprivation is
due in part to pubertal changes in the homeostatic and circadian regulation of sleep. These …

The circadian system actively synchronizes the temporal sequence of biological functions
with the environment. The oscillatory behavior of the system ensures that entrainment is not …

Daily rhythmicity, including timing of wakefulness and hormone secretion, is mainly
controlled by a master clock located in the suprachiasmatic nucleus (SCN) of the …

Time as an ecological niche variable or “temporal niche” can be defined in the context of the
most prominent environmental cycles, including the tidal cycle, the lunar day and month, the …

Virtually all species have developed cellular oscillations and mechanisms that synchronize
these cellular oscillations to environmental cycles. Such environmental cycles in biotic (eg …

Camera trapping allows scientists to study activity patterns of animals under natural
conditions. However, comparisons of activity patterns across seasons or latitudes can be …

What are phase-response curves (PRCs)? How can they be measured? How should they be
plotted? These questions and many other fascinating facets of PRCs are addressed in this …

This review provides an overview of the interaction between the mammalian cholinergic
system and circadian system, and its possible role in time memory. Several studies made …

Patients in an intensive care unit (ICU) may risk disruption of their circadian rhythm. In an
intervention research project a cycled lighting system was set up in an ICU room to support …