A bottom-mounted upward-facing 38-kHz echo sounder was deployed at ~400 m and cabled to shore in Masfjorden (~60°52'N, ~5°24'E), Norway. The scattering layers seen during autumn (September-October) 2008 were identified by trawling. Glacier lanternfish (Benthosema glaciale) were mainly distributed below ~200 m and displayed three different diel behavioral strategies: normal diel vertical migrati...

Efferent nerves coursing from the brain to the lateral eye of the horseshoe crab, Limulus polyphemus, increase its nighttime sensitivity to light. They release octopamine, which produces a categorical increase of photoreceptor response duration in vitro. Analogous in vivo timing effects on the electroretinogram (ERG) were demonstrated when octopamine was infiltrated into the eye of an otherwise...

Our aim was to investigate how circadian adaptation to night shift work affects psychomotor performance, sleep, subjective alertness and mood, melatonin levels, and heart rate variability (HRV). Fifteen healthy police officers on patrol working rotating shifts participated to a bright light intervention study with 2 participants studied under two conditions. The participants entered the laborat...

Red light running is estimated to account for 900 intersection crash fatalities annually. Two principal methods used to reduce red light running involve lengthening the duration of yellow change intervals and automated red light enforcement. The present study evaluated the incremental effects on red light running of first lengthening yellow signal timing, followed by the introduction of red lig...

A number of investigators have reported on the diurnal rhythm of locomotion in cockroaches, which shows a very similar picture in the different species. It is well documented that the releasing factor is a change from light to darkness (Gunn, 1940; Harker, 1956; de Roberts, i960). The rhythm persists under constant conditions, and this so-called free-running rhythm is remarkably temperature-ind...

AIM Shift workers may be at risk of different diseases. In order to assess cardiometabolic risk in shift workers, a cross-sectional study was performed among active workers. METHODS A total of 481 workers (121 men, 360 women) were investigated; most of them were employees in light industry (58.2%) or in public services (23.9%). Past medical history was recorded and physical examination was pe...

Intensive care units provide specialised care for critically ill patients around the clock. However, intensive care unit patients have disrupted circadian rhythms. Furthermore, disrupted circadian rhythms are associated with worse outcome. As light is the most powerful 're-setter' of circadian rhythm, we measured light intensity on intensive care unit. Light intensity was low compared to daylig...

BACKGROUND It is believed that the severely disturbed night-time sleep architecture after surgery is associated with increased cardiovascular morbidity with rebound of rapid eye movement (REM). The daytime sleep pattern of patients after major general surgery has not been investigated before. We decided to study the circadian distribution of sleep phases before and after surgery. METHODS Elev...