Circadian Rhythms

Decay of diel patterns of swimming activity in juvenile common snook (Centropomus undecimalis) maintained in captivity

by Greg Tolley

The canonical E-box motif: A target for glucocorticoid action that drives rhythmic mouse Pai-1 transcription in vitro

by Joanne Singletary

Circadian Typology, Age, and the Alternative Five-Factor Personality Model in an Adult Women Sample

by Anna Muro

Morningness-Eveningness, Sex, and the Alternative Five Factor Model of Personality

by Anna Muro

Diurnal locus as a predictor of daytime optimum and decline in medical staff performance (Суточный локус как предиктор дневного оптимума/спада в работе медицинского персонала

by Sergei Shchebetenko

Shchebetenko, S.A., & Semyonova, P.I. (2011). Diurnal locus as a predictor of daytime optimum and decline in medical staff performance. Psychology. Journal of the Higher School of Economics, 8, 130-138. (in Russian).

The possibility of predicting performance rise/decline among medical staff during their working shift is shown in the... more The possibility of predicting performance rise/decline among medical staff during their working shift is shown in the article. Theoretical backgrounds are briefly discussed. 189 medical staff members in Perm, Russia participated in the study. A self-report 6-item Diurnal Locus Scale was invented exhibiting an acceptable internal consistency as well as its construct (CFA), discriminant (regarding Rotter’s Locus of Control Scale), and predictive validity. Diurnal locus did not correlate with participants’ gender, t(187)<1, professional status (doctor vs. paramedical personnel), t(187)=1.29, p=.2, participants’ age, r=-.05, and general internality, r=.06. Meanwhile, Diurnal Locus correlated moderately with professional internality, r=.18, p=.013, such that the higher professional internality is, more morning-oriented locus is. Of importance, diurnal locus highly significantly predicted the assessment by managers of participants performance rise/decline during their working shift, r=.52, p<.001. Finally, diurnal locus fully mediated the positive correlation between professional internal locus of control and morning performance increase/evening performance decrease, Sobel’s test, Z=.2.42, p=.03. The results and limitations are further discussed in the article.

Temporal gradient in the clock gene and cell-cycle checkpoint kinase Wee1 expression along the gut

by Matus Sotak

Hepatic, Duodenal, and Colonic Circadian Clocks Differ in their Persistence under Conditions of Constant Light and in their Entrainment by Restricted Feeding

by Matus Sotak

Circadian regulation of electrolyte absorption in the rat colon.

by Matus Sotak

Imaging of single light-responsive clock cells reveals fluctuating free-running periods

by Amanda-Jayne Carr

Light reaches the very heart of the zebrafish clock

by Amanda-Jayne Carr

Evidence for an endogenous per1-and ICER-independent seasonal timer in the hamster pituitary gland

by Amanda-Jayne Carr

Photoperiod differentially regulates circadian oscillators in central and peripheral tissues of the Syrian hamster

by Amanda-Jayne Carr

The fish watch Zebrafish: a clock in every cell

by Amanda-Jayne Carr

Zebrafish circadian clocks: cells that see light

by Amanda-Jayne Carr

The tau Mutation in the Syrian Hamster Differentially Reprograms the Circadian Clock in the SCN and Peripheral Tissues

by Amanda-Jayne Carr

Imaging of single light-responsive clock cells reveals fluctuating free-running periods

by Amanda-Jayne Carr

Oscillation, cooperativity, and intermediates in the self-repressing gene

by David Lepzelter

Biological oscillators are vital to living organisms, which use them as clocks for time-sensitive processes. However,... more Biological oscillators are vital to living organisms, which use them as clocks for time-sensitive processes. However, much is unknown about mechanisms which can give rise to coherent oscillatory behavior, with few exceptions (e.g., explicitly delayed self-repressors and simple models of specific organisms’ circadian clocks). We present what may be the simplest possible reliable gene network oscillator, a self-repressing gene. We show that binding cooperativity, which has not been considered in detail in this context, can combine with small numbers of intermediate steps to create coherent oscillation. We also note that noise blurs the line between oscillatory and non-oscillatory behavior.

Role of the CLOCK Protein In the Mammalian Circadian Mechanism

by Hugh Nguyen

Co-Authored in Science Magazine.
Accepted for publication 18 May 1998.

The mouse Clock gene encodes a bHLH-PAS protein that regulates circadian rhythms and is related to transcription... more The mouse Clock gene encodes a bHLH-PAS protein that regulates circadian rhythms and is related to transcription factors that act as heterodimers. Potential partners of CLOCK were isolated in a two-hybrid screen, and one, BMAL1, was coexpressed with CLOCK and PER1 at known circadian clock sites in brain and retina. CLOCK-BMAL1 heterodimers activated transcription from E-box elements, a type of transcription factor–binding site, found adjacent to the mouseper1 gene and from an identical E-box known to be important for per gene expression in Drosophila. Mutant CLOCK from the dominant-negative Clock allele and BMAL1 formed heterodimers that bound DNA but failed to activate transcription. Thus, CLOCK-BMAL1 heterodimers appear to drive the positive component of per transcriptional oscillations, which are thought to underlie circadian rhythmicity.

Chronobiology of dreaming (2004)

by Tore Nielsen

Seasonal and daily activity patterns of subterranean, wood-eating termite foragers

by Theodore Evans

Australian Journal of Zoology 49, 311–321

Daily and seasonal changes in foraging activity of subterranean wood-feeding termites are not well known, but their... more Daily and seasonal changes in foraging activity of subterranean wood-feeding termites are not well known, but their subterranean habit is widely assumed to reduce the effect of the weather on their behaviour. The number of foraging Coptotermes lacteus in artificial feeding stations was examined over 24-h periods during summer and winter in temperate Australia. In summer, termites foraged disparately, with greater numbers found distant from the mounds, whereas in winter termites were clustered in very high numbers near the mounds. Daily patterns were seen in forager numbers: during summer, peaks occurred in late morning and late afternoon and troughs at dawn and noon, whereas in winter a peak occurred at noon and a trough at dawn. These patterns were associated with air and soil temperatures, which indicated that daily and seasonal weather patterns do influence subterranean wood-feeding termites. The foraging pattern is discussed with respect to predator behaviour and how the pattern might be used to infer positioning of cryptic nesting termite species.