This paper uses a spatial regression discontinuity design to identify the health effects of the misalignment between social and biological time induced by different sunset times and the fact that social schedules are not responsive to solar cues. Exploiting the discontinuity in the timing of natural light provided by the existence of time zones, we find that being exposed to more light in the e...

BACKGROUND Injuries and deaths from road traffic crashes are one of the main public health problems throughout the world. This study aimed to identify determinants of fatality traffic accident in Iran for the twenty-span year from 1991 to 2011. METHODS A time series analysis (1991-2011) was used to examine the effects of some of the key explanatory factors (GDP per capita, number of doctors p...

Shift work generally is defined as work hours that are scheduled outside of daylight. Shift work disrupts the synchronous relationship between the body's internal clock and the environment. The disruption often results in problems such as sleep disturbances, increased accidents and injuries, and social isolation. Physiologic effects include changes in rhythms of core temperature, various hormon...

Overt 24-h rhythmicity is composed of both exogenous and endogenous components, reflecting the product of multiple (periodic) feedback loops with a core pacemaker at their center. Researchers attempting to reveal the endogenous circadian (near 24-h) component of rhythms commonly conduct their experiments under constant environmental conditions. However, even under constant environmental conditi...

Circadian rhythm sleep disorders are common in clinical practice. The disorders covered in this review are delayed sleep phase disorder, advanced sleep phase disorder, free-running, irregular sleep-wake rhythm, jet lag disorder and shift work disorder. Bright light treatment and exogenous melatonin administration are considered to be the treatments of choice for these circadian rhythm sleep dis...

OBJECTIVE Millions of adults in the United States travel abruptly across time zones each year. Nevertheless, the impact of traveling over relatively short distances (across 3 or fewer time zones) on diurnal patterning of typical physiological response patterns has yet to be studied in a large, epidemiological sample. DESIGN The current research focuses on 764 middle-aged men comparing variati...

Microbes have been catapulted into the spotlight again by recent studies showing that uniquely modern phenomena, like jet lag and artificial sweeteners, can affect health by altering the microbiome (Suez et al., 2014; Thaiss et al., 2014). However, even as the nature of our current relationship with bacteria unfolds, DNA sequencing and proteomic approaches are giving us a fascinating glimpse in...

A daily rhythm that is not in synchrony with the environmental light-dark cycle (as in jetlag and shift work) is known to affect mood and health through an as yet unresolved neural mechanism. Here, we combine Bayesian probabilistic 'cue-conflict' theory with known physiology of the biological clock of the brain, entailing the insight that, for a functional pacemaker, it is sufficient to have tw...

Cryptochrome (CRY) is a blue-light sensitive flavoprotein that functions as the primary circadian photoreceptor in Drosophila melanogaster. The mechanism by which it transmits the light signal to the core clock circuitry is not known. We conducted in vitro studies on the light-induced conformational change in CRY and its effect on protein-protein interaction and performed in vivo analysis of th...

We attempted investigate a boat model, based on the conversion of energy of surface wave into a sequence of unidirectional pulses of jet spurts, in other words model of the boat, which is thrusting by the waves field on water surface. These pulses are forming some average reactive stream from the output nozzle on the stern of boat. The suggested model provides the conversion of its oscillatory ...