Sleep complaints are consistently cited as the most prominent health and well-being problem in Arctic and Antarctic expeditions, without clear evidence to identify the causal mechanisms. The present investigation aimed at studying sleep and determining circadian regulation and mood during a 4-mo Antarctic summer expedition. All data collection was performed during the continuous illumination of...

Experimental fasting has been shown to alter the sleep-wakefulness pattern in various species. As fasting during Ramadan is distinct from experimental fasting, the physiological and behavioural changes occurring during Ramadan fasting may differ from those occurring during experimental fasting. There has been increased interest in recent years in sleep changes and daytime sleepiness during Rama...

Endogenous biological clocks enable living species to acquire some independence in relation to time. They improve the efficiency of biological systems, by allowing them to anticipate future constraints on major physiological systems and cell energy metabolism. The temporal organization of a given biological function can be impaired in its coordination with astronomical time or with other biolog...

Circadian rhythms (approximately 24h) are widely characterized at molecular level and their generation is acknowledged to originate from oscillations in expression of several clock genes and from regulation of their protein products. While general entrainment of organisms to environmental light-dark cycles is mainly achieved through the master clock of the suprachiasmatic nucleus in mammals, th...

Diurnal variation in body composition in relation to chronobiological parameters was analyzed in 27 healthy students (22-29 years) four times over one day from 5:35 to 0:15 h. Body composition was determined by multifrequency bioimpedance analysis at fixed frequencies (1, 5, 50, 100 kHz). Resistance (R) and reactance (Xc) were measured. Total, extra and intracellular body water (TBW, ECW, ICW),...

A major question in chronobiology focuses around the "Bünning hypothesis" which implicates the circadian clock in photoperiodic (day-length) measurement and is supported in some systems (e.g. plants) but disputed in others. Here, we used the seasonally-regulated thermotolerance of Drosophila melanogaster to test the role of various clock genes in day-length measurement. In Drosophila, freezing ...

Valerio Pazienza,* Cristoforo Pomara,* Francesco Cappello, Raffaele Calogero, Matteo Carrara, Gianluigi Mazzoccoli,* and Manlio Vinciguerra* Division of Gastroenterology, Department of Medical Sciences, IRCCS Scientific Institute “Casa Sollievo della Sofferenza,” San Giovanni Rotondo, Italy; Department of Anatomy, University of Malta, Msida, Malta; Department of Forensic Pathology, University o...