Prevalence of sleep disturbance among Chinese healthcare professionals increases Eastward-caution with position in time zone.

We analyze data of the prevalence of sleep disturbance among Chinese healthcare professionals and maintain that they increase Eastward, refining previous results. We suggest that position in time zone is a valid explanatory metric only after daily rhythms have been uniformed. On a more general note, this finding suggest that daylight saving time might help reduce sleep disturbance.

Sample size bias in the empirical assessment of the acute risks associated with daylight saving time transitions.

The assessment of the acute impact of daylight saving time (DST) transitions is a question of great interest for an understanding of the benefits and inconveniences of a practice that is now under public scrutiny in Europe and America. Here, we report a thorough analysis of a record of 13 well-known research studies that reported increased risks associated with DST transitions in health issues - acute myocardial infarction, ischemic strokes and trauma admissions - and in societal issues - accidents, traffic accidents and fatal motor vehicle accidents. We found that a five percent increase of the risks suffices to understand the reported increased risks associated with the spring transition.

A chronobiological evaluation of the risks of canceling daylight saving time.

The long-term impact of seasonal regulation of clocks (Daylight Saving Time) is analyzed showing that it helped to mitigate the advance of the phase of human activity during the twentieth century and the exposure to the hours of the dawn in winter. The increased risks induced by circadian misalignment around transition dates are balanced by a better alignment of social clocks to the natural day in summer and in winter.

Traffic accident increase attributed to Daylight Saving Time doubled after Energy Policy Act.

Martín-Olalla argues that an important factor in the association between motor vehicle fatalities and the switch to Daylight Saving Time is the timing of the switch, which in the US changed with the Energy Policy Act of 2005.

The long term impact of Daylight Saving Time regulations in daily life at several circles of latitude.

We analyze large scale (N ~ 10000) time use surveys in United States, Spain, Italy, France and Great Britain to ascertain seasonal variations in the sleep/wake cycle and the labor cycle after daylight saving time regulations have stood up for at least forty years. That is, not the usual search for the impact of the biannual transitions, but a search for how industrialized societies have answered to DST regulations at different circles of latitude. Results show that the labor cycle is equally distributed through seasons if measured in local time.

Publisher Correction: Seasonal synchronization of sleep timing in industrial and pre-industrial societies.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Seasonal synchronization of sleep timing in industrial and pre-industrial societies.

Artificial light has reshaped human sleep/wake cycle in industrial societies and raised concern on the misalignment of this cycle relative to the light and dark cycle. This manuscript contrasts sleep timing in extratropical, industrial societies (data from eight national time use surveys in countries with Daylight Saving Time -DST- regulations) and Subtropical, pre-industrial societies with and without access to artificial light (data from nine locations coming from seven previous reports) against the cycle of light and dark. Within the two process model of sleep, results show sleep onset and sleep offset keep bound to each other by the homeostatic process.

Latitudinal trends in human primary activities: characterizing the winter day as a synchronizer.

This work analyzes time use surveys from 19 countries (17 European and 2 American) in the middle latitude (38-61 degree) accounting for 45% of world population in this range. Time marks for primary activities are contrasted against light/dark conditions. The analysis reveals winter sunrise synchronizes labor start time below 54 degree, occurring within winter civil twilight.

Avalanche correlations in the martensitic transition of a Cu-Zn-Al shape memory alloy: analysis of acoustic emission and calorimetry.

The existence of temporal correlations during the intermittent dynamics of a thermally driven structural phase transition is studied in a Cu-Zn-Al alloy. The sequence of avalanches is observed by means of two techniques: acoustic emission and high sensitivity calorimetry. Both methods reveal the existence of event clustering in a way that is equivalent to the Omori correlations between aftershocks in earthquakes as are commonly used in seismology.