scholarly journals Activity and light exposure patterns in flight crew

2003 ◽  
Author(s):  
Raymond Lawrence Oyung
Keyword(s):  
Light Exposure ◽  
Flight Crew ◽  
Exposure Patterns

scholarly journals Telling the Seasons Underground: The Circadian Clock and Ambient Temperature Shape Light Exposure and Photoperiodism in a Subterranean Rodent

2021 ◽  
Vol 12 ◽  
Author(s):  
Danilo E. F. L. Flôres ◽  
Milene G. Jannetti ◽  
Giovane C. Improta ◽  
Patricia Tachinardi ◽  
Veronica S. Valentinuzzi ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Laboratory Experiments ◽  
Light Exposure ◽  
Seasonal Patterns ◽  
Subterranean Rodents ◽  
Subterranean Rodent ◽  
Lighting Conditions ◽  
Oscillatory Structure ◽  
Exposure Patterns ◽  
Living Organisms

Living organisms anticipate the seasons by tracking the proportion of light and darkness hours within a day—photoperiod. The limits of photoperiod measurement can be investigated in the subterranean rodents tuco-tucos (Ctenomys aff. knighti), which inhabit dark underground tunnels. Their exposure to light is sporadic and, remarkably, results from their own behavior of surface emergence. Thus, we investigated the endogenous and exogenous regulation of this behavior and its consequences to photoperiod measurement. In the field, animals carrying biologgers displayed seasonal patterns of daily surface emergence, exogenously modulated by temperature. In the laboratory, experiments with constant lighting conditions revealed the endogenous regulation of seasonal activity by the circadian clock, which has a multi-oscillatory structure. Finally, mathematical modeling corroborated that tuco-tuco’s light exposure across the seasons is sufficient for photoperiod encoding. Together, our results elucidate the interrelationship between the circadian clock and temperature in shaping seasonal light exposure patterns that convey photoperiod information in an extreme photic environment.

Association of time outdoors and patterns of light exposure with myopia in children

2021 ◽  
pp. bjophthalmol-2021-318918
Author(s):  
Mijie Li ◽  
Carla Lanca ◽  
Chuen-Seng Tan ◽  
Li-Lian Foo ◽  
Chen-Hsin Sun ◽  
...  
Keyword(s):  
Light Exposure ◽  
Total Duration ◽  
Growing Up ◽  
Spherical Equivalent ◽  
Outdoor Activities ◽  
Light Levels ◽  
Exposure Patterns ◽  
Activity Diary ◽  
Generalised Estimating Equations ◽  
Multiethnic Children

Background/aimsTo evaluate the association of reported time outdoors and light exposure patterns with myopia among children aged 9 years from the Growing Up in Singapore Towards Healthy Outcomes birth cohort.MethodsWe assessed reported time outdoors (min/day), light exposure patterns and outdoor activities of children aged 9 years (n=483) with a questionnaire, the FitSight watch and a 7-day activity diary. Light levels, the duration, timing and frequency of light exposure were assessed. Cycloplegic spherical equivalent (SE), myopia (SE≤−0.5 D) and axial length (AL) of paired eyes were analysed using generalised estimating equations.ResultsIn this study, 483 (966 eyes) multiethnic children (50.0% boys, 59.8% Chinese, 42.2% myopic) were included. Reported time outdoors (mean±SD) was 100±93 min/day, and average light levels were 458±228 lux. Of the total duration children spent at light levels of ≥1000 lux (37±19 min/day), 76% were spent below 5000 lux. Peak light exposure occurred at mid-day. Children had 1.7±1.0 light exposure episodes/day. Common outdoor activities were walks, neighbourhood play and swimming. Greater reported time outdoors was associated with lower odds of myopia (OR=0.82, 95% CI 0.70 to 0.95/hour increase daily; p=0.009). Light levels, timing and frequency of light exposures were not associated with myopia, SE or AL (p>0.05).ConclusionReported time outdoors, light levels and number of light exposure episodes were low among Singaporean children aged 9 years. Reported time outdoors was protective against myopia but not light levels or specific light measures. A multipronged approach to increase time outdoors is recommended in the combat against the myopia epidemic.

scholarly journals Light Exposure Patterns in Healthy Older and Young Adults

2010 ◽  
Vol 25 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Karine Scheuermaier ◽  
Alison M. Laffan ◽  
Jeanne F. Duffy
Keyword(s):  
Young Adults ◽  
Light Exposure ◽  
Exposure Patterns

scholarly journals Light exposure patterns and sleep in children

2019 ◽  
Vol 3 ◽  
pp. 170-171
Author(s):  
Huss A ◽  
van Wel L ◽  
Bogaards L ◽  
Vrijkotte T ◽  
Vermeulen R
Keyword(s):  
Light Exposure ◽  
Exposure Patterns

scholarly journals Exploring light exposure of hospital nurses working rapidly rotating shifts in relation to sleepiness and sleep

2021 ◽  
Vol 2042 (1) ◽  
pp. 012111
Author(s):  
Mariëlle P.J. Aarts ◽  
Steffen L. Hartmeyer ◽  
Kars Morsink ◽  
Helianthe S.M. Kort
Keyword(s):  
Visual Inspection ◽  
Intervention Studies ◽  
Light Exposure ◽  
Hospital Nurses ◽  
Negative Effects ◽  
Limited Sample ◽  
Circadian Phase ◽  
Exposure Patterns ◽  
The Individual ◽  
Careful Manipulation

Abstract Nightshift work can negatively impact sleep, performance, and health. Careful manipulation of light exposure patterns can help reduce these negative effects but is challenging in conditions of rapidly rotating shiftwork and due to individual differences. As chronotype is related to shiftwork tolerance, we explored patterns of sleep, sleepiness, and light exposure during the first day of nightshift work between earlier and later chronotypes, based on data from an observational field study among rapidly rotating hospital nurses. Due to the limited sample size, only descriptive analyses and visual inspection were conducted. In line with findings of lower shiftwork tolerance, earlier chronotypes (N=6) seemed to be sleepier during work and sleep less than later types (N=7). Differences were also observed in light exposure patterns, revealing potential for light exposure interventions, and suggesting a contribution to shiftwork tolerance. For future intervention studies in aiming to identify a light exposure strategy, our findings highlight the importance of investigating light exposure relative to the individual circadian phase.

What determines our light exposure patterns and how do we quantify them?

2019 ◽  
Vol 64 ◽  
pp. S355
Author(s):  
A. Skeldon ◽  
N. Santhi ◽  
T. Shochat ◽  
S. Flavell ◽  
D.-J. Dijk
Keyword(s):  
Light Exposure ◽  
Exposure Patterns

scholarly journals Quantifying light exposure patterns in young adult students

2013 ◽  
Vol 60 (14) ◽  
pp. 1200-1208 ◽  
Author(s):  
Amanda A. Alvarez ◽  
Christine F. Wildsoet
Keyword(s):  
Young Adult ◽  
Adult Students ◽  
Light Exposure ◽  
Exposure Patterns

scholarly journals Measuring Incident Light on Grape Clusters Using Photosensitive Paper and Image Analysis

1995 ◽  
Vol 120 (2) ◽  
pp. 235-240 ◽  
Author(s):  
Steven F. Price ◽  
Marc L. Schuette ◽  
Elizabeth Tassie
Keyword(s):  
Image Analysis ◽  
Light Exposure ◽  
Spectral Response ◽  
Incident Light ◽  
Light Distribution ◽  
Ecological Studies ◽  
Plant Canopies ◽  
Exposure Patterns ◽  
Average Irradiance ◽  
Individual Paper

Digital imaging and analysis was used to quantify and characterize the light exposure patterns of photosensitive paper tubes placed in representative cluster positions in two grape (Vitis vinifera L.) canopies: a minimally pruned and a vertically trained canopy. Blue pixel values of the captured images had a negative correlation with the log of irradiance from an integrating quantum sensor (r2 = 0.9308). The spectral response of the photosensitive paper was not measured. Histograms of incident light distribution on individual paper tubes were developed using imaging software. Histograms were able to quantify the distribution of incident light on individual tubes and were clearly related to the tube's exposure in the canopy. Average population curves of pixel light distribution of 20 tubes in each canopy were able to differentiate the typical cluster light environment in the two canopies. Tubes in the minimally pruned canopy had a larger proportion of their surface exposed to irradiances > 50 μmol·s-1·m-2 and 65% higher average irradiance than the vertical canopy. Image analysis of photosensitive paper appears to be a workable method to record the distribution ofincident light in plant canopies and may have utility in a range of ecological studies.

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