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Author Cajochen, C.; Frey, S.; Anders, D.; Spati, J.; Bues, M.; Pross, A.; Mager, R.; Wirz-Justice, A.; Stefani, O. url  doi
openurl 
  Title Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance Type Journal Article
  Year 2011 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol (1985)  
  Volume 110 Issue 5 Pages 1432-1438  
  Keywords Adult; Circadian Rhythm/*physiology/radiation effects; Cognition/*physiology/radiation effects; *Computer Terminals; Humans; Light; Lighting/*methods; Male; Photic Stimulation/*methods; Radiation Dosage; Semiconductors; *Task Performance and Analysis; Young Adult; blue light; sleep; circadian disruption  
  Abstract Many people spend an increasing amount of time in front of computer screens equipped with light-emitting diodes (LED) with a short wavelength (blue range). Thus we investigated the repercussions on melatonin (a marker of the circadian clock), alertness, and cognitive performance levels in 13 young male volunteers under controlled laboratory conditions in a balanced crossover design. A 5-h evening exposure to a white LED-backlit screen with more than twice as much 464 nm light emission {irradiance of 0,241 Watt/(steradian x m(2)) [W/(sr x m(2))], 2.1 x 10(13) photons/(cm(2) x s), in the wavelength range of 454 and 474 nm} than a white non-LED-backlit screen [irradiance of 0,099 W/(sr x m(2)), 0.7 x 10(13) photons/(cm(2) x s), in the wavelength range of 454 and 474 nm] elicited a significant suppression of the evening rise in endogenous melatonin and subjective as well as objective sleepiness, as indexed by a reduced incidence of slow eye movements and EEG low-frequency activity (1-7 Hz) in frontal brain regions. Concomitantly, sustained attention, as determined by the GO/NOGO task; working memory/attention, as assessed by “explicit timing”; and declarative memory performance in a word-learning paradigm were significantly enhanced in the LED-backlit screen compared with the non-LED condition. Screen quality and visual comfort were rated the same in both screen conditions, whereas the non-LED screen tended to be considered brighter. Our data indicate that the spectral profile of light emitted by computer screens impacts on circadian physiology, alertness, and cognitive performance levels. The challenge will be to design a computer screen with a spectral profile that can be individually programmed to add timed, essential light information to the circadian system in humans.  
  Address Centre for Chronobiology, Psychiatric Hospitals of the University of Basel, Basel, Switzerland. christian.cajochen@upkbs.ch  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0161-7567 ISBN (down) Medium  
  Area Expedition Conference  
  Notes PMID:21415172 Approved no  
  Call Number IDA @ john @ Serial 293  
Permanent link to this record
 

 
Author Bennett, S.; Alpert, M.; Kubulins, V.; Hansler, R.L. url  doi
openurl 
  Title Use of modified spectacles and light bulbs to block blue light at night may prevent postpartum depression Type Journal Article
  Year 2009 Publication Medical Hypotheses Abbreviated Journal Med Hypotheses  
  Volume 73 Issue 2 Pages 251-253  
  Keywords Depression, Postpartum/*prevention & control; *Eyeglasses; Female; Humans; *Lighting; blue light; light therapy; blue blocker  
  Abstract In 2001 it was discovered that exposing the eyes to light in the blue end of the visible spectrum suppresses the production of the sleep hormone, melatonin. New mothers need to get up during the night to care for their babies. This is the time when melatonin is normally flowing. Exposing their eyes to light can cut off the flow. It may also reset their circadian (internal) clock. On subsequent nights the melatonin may not begin flowing at the normal time making it difficult to fall asleep. Over time, disruption of the circadian rhythm plus sleep deprivation may result in depression. Women suffering postpartum depression were enrolled in a small clinical trial. Some were provided with glasses and light bulbs that block blue light. Others were equipped with glasses and light bulbs that looked colored but did not block the rays causing melatonin suppression. Those with the “real glasses” recovered somewhat more quickly than those with the placebo glasses and light bulbs. The hypothesis that should be tested in large scale clinical trials is that the risk of postpartum depression can be reduced when a new mother avoids exposing her eyes to blue light when she gets up at night to care for her baby. In the meantime, all new mothers may benefit from using glasses and light bulbs that block blue light when getting up at night to care for their babies.  
  Address Postpartum Support, International P.O. Box 60931, Santa Barbara, CA 93160, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0306-9877 ISBN (down) Medium  
  Area Expedition Conference  
  Notes PMID:19329259 Approved no  
  Call Number IDA @ john @ Serial 296  
Permanent link to this record
 

 
Author Semeniuk, Kent (ed) pdf  url
openurl 
  Title Gazing Up: An Exploration of Municipal Night Lighting Practices Amongst Six Canadian Municipalities Type Manuscript
  Year 2014 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords light pollution; public policy; Canada; outdoor lighting; municipal  
  Abstract Light pollution is broadly defined as the unnecessary illumination of the nocturnal environment. Light pollution is a pervasive phenomena shown to have harmful consequences for both the biotic and abiotic components of an ecosystem. While some municipalities have begun to address the environmental and economic costs of light pollution, most have not. The goal of this study was to investigate current municipal night lighting practices for six selected Canadian municipalities with the aim of determining their policies and practices for night lighting. Semi-structured interviews with key informants were conducted and analyzed using a mixed methods approach that included a thorough literature review. The results indicate that rising energy costs, aging infrastructure and the lighting industry are driving the majority of changes taking place in adapting municipalities while most municipalities remain content with status quo. The research conducted led to guideline improvements for municipal night lighting in today’s municipalities.  
  Address School of Environmental Design and Rural Development, University of Guelph  
  Corporate Author Thesis Master's thesis  
  Publisher University of Guelph Place of Publication Guelph, Ontario Editor Semeniuk, Kent  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN (down) Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 305  
Permanent link to this record
 

 
Author Fotios, S.; Yang, B.; Uttley, J. url  openurl
  Title Observing other pedestrians: Investigating the typical distance and duration of fixation Type Journal Article
  Year 2014 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technologying Res & Tech  
  Volume 47 Issue 5 Pages 548-564  
  Keywords traffic safety; pedestrians; roadway lighting; visibility; light at night  
  Abstract After dark, road lighting should enhance the visual component of pedestrians’ interpersonal judgements such as evaluating the intent of others. Investigation of lighting effects requires better understanding of the nature of this task as expressed by the typical distance at which the judgement is made (and hence visual size) and the duration of observation, which in past studies have been arbitrary. Better understanding will help with interpretation of the significance of lighting characteristics such as illuminance and light spectrum. Conclusions of comfort distance in past studies are not consistent and hence this article presents new data determined using eye-tracking. We propose that further work on interpersonal judgements should examine the effects of lighting at a distance of 15 m with an observation duration of 500 ms.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN (down) Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 309  
Permanent link to this record
 

 
Author Liu, X.Y.; Luo, M.R.; Li, H. url  openurl
  Title A study of atmosphere perceptions in a living room Type Journal Article
  Year 2014 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology  
  Volume 47 Issue 5 Pages 581-594  
  Keywords lighting; indoor lighting; perception; Chinese; Dutch; aesthetics  
  Abstract An experiment has been carried out to investigate the effect of lighting on the perception of atmosphere in a living room, using three types of light sources: halogen, fluorescent and LED lamps. In a psychophysical experiment, 29 native Chinese observers assessed eight lighting conditions having different luminances and correlated colour temperatures. For each condition, 71 scales were employed using the categorical judgment method. Factor analysis identified two underlying dimensions: liveliness and cosiness. This agrees with those found by Vogels who used Dutch observers to assess atmosphere perception. Both observer groups also agreed that an increase of luminance would make the room more lively. However, there were also some disagreements such as a higher CCT source would make the room more lively for Chinese observers but less lively for Dutch observers.  
  Address State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou, China  
  Corporate Author Thesis  
  Publisher SAGE Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN (down) Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 310  
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