Exposure to light at night increases alertness, but light at night (especially short-wavelength light) also disrupts nocturnal physiology. Such disruption is thought to underlie medical problems for which shiftworkers have increased risk. In 33 male subjects we investigated whether short-wavelength attenuated polychromatic white light (<530 nm filtered out) at night preserves dim light melatoni...

Light traps have been used widely to sample insect abundance and diversity, but their performance for sampling scarab beetles in tropical forests based on light source type and sampling hours throughout the night has not been evaluated. The efficiency of mercury-vapour lamps, cool white light and ultraviolet light sources in attracting Dynastinae, Melolonthinae and Rutelinae scarab beetles, and...

There are three mechanisms that may contribute to the health, performance, and safety problems associated with night-shift work: (1) circadian misalignment between the internal circadian clock and activities such as work, sleep, and eating, (2) chronic, partial sleep deprivation, and (3) melatonin suppression by light at night. The typical countermeasures, such as caffeine, naps, and melatonin ...

Hospitalized elders frequently experience disturbed sleep related to environmental factors. To determine relationships between sleep and environmental noise and light, a descriptive exploratory study was conducted with 48 hospitalized older adults. Participants aged 70 years or older were monitored for sleep via wrist actigraphy, and noise and light levels were measured the first night of hospi...

A thought experiment places Henry Ford and Thomas Alva Edison in a modern regulatory environment. In a utopian occupational world devoid of night-shifts or artificial light, Ford wants to experiment with "working through the night". To support Ford's project, Edison offers his patented electric lamps to "turn nights into days". An ethics committee [EC] does not approve the night-work experiment...

Circadian systems are entrained and phase shifted by light. In Drosophila, the model of light-mediated phase shifting begins with photon capture by CRYPTOCHROME (CRY) followed by rapid TIMELESS (TIM) degradation. In this study, we focused on phase delays and assayed TIM degradation within individual brain clock neurons in response to light pulses in the early night. Surprisingly, there was no d...

Change in day length is an important cue for reproductive activation in seasonally breeding animals to ensure that the timing of greatest maternal investment (e.g. lactation in mammals) coincides with favourable environmental conditions (e.g. peak productivity). However, artificial light at night has the potential to interfere with the perception of such natural cues. Following a 5-year study o...

Night-time light imagery stands unique amongst remote sensing data sources as it offers a uniquely ‘human’ view of the Earth’s surface. The presence of lighting across the globe is almost entirely due to some form of human activity be it settlements, shipping fleets, gas flaring or fires associated with swidden agriculture. This extensively illustrated guide introduces users to the types of nig...