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Author Komada, Y.; Aoki, K.; Gohshi, S.; Ichioka, H.; Shibata, S. url  doi
openurl 
  Title Effects of television luminance and wavelength at habitual bedtime on melatonin and cortisol secretion in humans: Blue light and melatonin secretion Type Journal Article
  Year 2015 Publication Sleep and Biological Rhythms Abbreviated Journal Sleep and Biological Rhythms  
  Volume 13 Issue 4 Pages 316–322  
  Keywords Human Health  
  Abstract The aim of this study was to examine the effect of exposure to different types of television displays at habitual bedtime on human melatonin and cortisol secretion. Thirteen male participants (mean age: 22.7 ± 0.85 years) were tested over three nights in one baseline and two experimental sessions. Participants were instructed to watch a movie on four different luminance- and wavelength-controlled television displays: normal luminance (450 candela [cd]/m2) or high luminance (1200 cd/m2) and normal blue light or half blue light. Salivary melatonin and cortisol levels were measured at two time points before and after television viewing. There was no significant difference in cortisol secretion due to the different displays. Melatonin suppression was significantly lower following the exposure to the half-blue light display compared with the normal blue light display. These results suggest that the use of half-blue light displays during night time may prevent circadian rhythm dysfunction.  
  Address  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1446-9235 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ christopher.kyba @ Serial 1149  
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Author Kavcic, P.; Rojc, B.; Dolenc-Groselj, L.; Claustrat, B.; Fujs, K.; Poljak, M. url  doi
openurl 
  Title The impact of sleep deprivation and nighttime light exposure on clock gene expression in humans Type Journal Article
  Year 2011 Publication Croatian Medical Journal Abbreviated Journal Croat Med J  
  Volume 52 Issue 5 Pages 594-603  
  Keywords genomics; epigenetics; hPer2; hBmal1; clock genes; gene expression; biology; human health  
  Abstract Aim

To examine the effect of acute sleep deprivation under light conditions on the expression of two key clock genes, hPer2 and hBmal1, in peripheral blood mononuclear cells (PBMC) and on plasma melatonin and cortisol levels.

Methods

Blood samples were drawn from 6 healthy individuals at 4-hour intervals for three consecutive nights, including a night of total sleep deprivation (second night). The study was conducted in April-June 2006 at the University Medical Centre Ljubljana.

Results

We found a significant diurnal variation in hPer2 and hBmal1 expression levels under baseline (P < 0.001, F = 19.7, df = 30 for hPer2 and P < 0.001, F = 17.6, df = 30 for hBmal1) and sleep-deprived conditions (P < 0.001, F = 9.2, df = 30 for hPer2 and P < 0.001, F = 13.2, df = 30 for hBmal1). Statistical analysis with the single cosinor method revealed circadian variation of hPer2 under baseline and of hBmal1 under baseline and sleep-deprived conditions. The peak expression of hPer2 was at 13:55 ± 1:15 hours under baseline conditions and of hBmal1 at 16:08 ± 1:18 hours under baseline and at 17:13 ± 1:35 hours under sleep-deprived conditions. Individual cosinor analysis of hPer2 revealed a loss of circadian rhythm in 3 participants and a phase shift in 2 participants under sleep-deprived conditions. The plasma melatonin and cortisol rhythms confirmed a conventional alignment of the central circadian pacemaker to the habitual sleep/wake schedule.

Conclusion

Our results suggest that 40-hour acute sleep deprivation under light conditions may affect the expression of hPer2 in PBMCs.
 
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0353-9504 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 135  
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Author Reiter, R.; Tan, D.; SanchezBarcelo, E.; Mediavilla, M.; Gitto, E.; Korkmaz, A. url  doi
openurl 
  Title Circadian mechanisms in the regulation of melatonin synthesis: disruption with light at night and the pathophysiological consequences Type Journal Article
  Year 2011 Publication Journal of Experimental and Integrative Medicine Abbreviated Journal J Exp Integr Med  
  Volume 1 Issue 1 Pages 13  
  Keywords Human Health  
  Abstract In the past two decades, the results of a number of epidemiological studies have uncovered an association between excessive light exposure at night and the prevalence of cancer. Whereas the evidence supporting this link is strongest between nighttime light and female breast and male prostate cancer, the frequency of other tumor types may also be elevated. Individuals who have the highest reported increase in cancer are chronic night shift workers and flight attendants who routinely fly across numerous time zones.

There are at least two obvious physiological consequences of nighttime light exposure, i.e., a reduction in circulating melatonin levels and disruption of the circadian system (chronodisruption). Both these perturbations in experimental animals aggravate tumor growth. Melatonin has a long investigative history in terms of its ability to stymie the growth of many tumor types. Likewise, in the last decade chronodisruption has been unequivocally linked to a variety of abnormal metabolic conditions including excessive tumor growth.

This brief review summarizes the processes by which light after darkness onset impedes melatonin production and disturbs circadian rhythms. The survey also reviews the evidence associating the ostensible danger of excessive nighttime light pollution to cancer risk. If an elevated tumor frequency is definitively proven to be a consequence of light at night and/or chronodisruption, it seems likely that cancer will not be the exclusive pathophysiological change associated with the rampant light pollution characteristic of modern societies.
 
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1309-4572 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 137  
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Author Lin, J.B.; Gerratt, B.W.; Bassi, C.J.; Apte, R.S. url  doi
openurl 
  Title Short-Wavelength Light-Blocking Eyeglasses Attenuate Symptoms of Eye Fatigue Type Journal Article
  Year 2017 Publication Investigative Ophthalmology & Visual Science Abbreviated Journal Invest Ophthalmol Vis Sci  
  Volume 58 Issue 1 Pages 442-447  
  Keywords Human Health  
  Abstract Purpose: The purpose of this study was to determine whether subjects who wear short wavelength-blocking eyeglasses during computer tasks exhibit less visual fatigue and report fewer symptoms of visual discomfort than subjects wearing eyeglasses with clear lenses. Methods: A total of 36 healthy subjects (20 male; 16 female) was randomized to wearing no-block, low-blocking, or high-blocking eyeglasses while performing a 2-hour computer task. A masked grader measured critical flicker fusion frequency (CFF) as a metric of eye fatigue and evaluated symptoms of eye strain with a 15-item questionnaire before and after computer use. Results: We found that the change in CFF after the computer task was significantly more positive (i.e., less eye fatigue) in the high-block versus the no-block (P = 0.027) and low-block (P = 0.008) groups. Moreover, random assignment to the high-block group but not to the low-block group predicted a more positive change in CFF (i.e., less eye fatigue) following the computer task (adjusted beta = 2.310; P = 0.002). Additionally, subjects wearing high-blocking eyeglasses reported significantly less feeling pain around/inside the eye (P = 0.0063), less feeling that the eyes were heavy (P = 0.0189), and less feeling that the eyes were itchy (P = 0.0043) following the computer task, when compared to subjects not wearing high-blocking lenses. Conclusions: Our results support the hypothesis that short-wavelength light-blocking eyeglasses may reduce eye strain associated with computer use based on a physiologic correlate of eye fatigue and on subjects' reporting of symptoms typically associated with eye strain.  
  Address Department of Ophthalmology & Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States 4Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States 5Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States  
  Corporate Author Thesis (up)  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0146-0404 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:28118668 Approved no  
  Call Number LoNNe @ kyba @ Serial 1629  
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Author Kretschmer, V.; Schmidt, K.-H.; Griefahn, B. url  doi
openurl 
  Title Bright light effects on working memory, sustained attention and concentration of elderly night shift workers Type Journal Article
  Year 2012 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology  
  Volume 44 Issue 3 Pages 316-333  
  Keywords shift work; light at night; light exposure; memory; concentration; human health  
  Abstract Night shift workers show a decline in performance during working time. Due to demographic change, the labour market requires more elderly people to work at night. Ageing is accompanied by a decrease in cognitive abilities, in the capabilities of the visual system and in coping with night work from the age of 40 onwards. This investigation focuses on the effects of bright light exposure on the working memory, concentration and sustained attention of elderly persons during three consecutive night shifts. After statistical control for neuroticism and intelligence as covariates, the results demonstrate that exposure to bright light at night reduces error rates for a working memory task and a concentration performance task but performance on a sustained attention task is completely unaffected.  
  Address  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1477-1535 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 147  
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