|   | 
Details
   web
Records
Author Kayaba, M.; Iwayama, K.; Ogata, H.; Seya, Y.; Tokuyama, K.; Satoh, M.
Title Drowsiness and low energy metabolism in the following morning induced by nocturnal blue light exposure Type Journal Article
Year 2013 Publication Sleep Medicine Abbreviated Journal Sleep Medicine
Volume 14 Issue Pages e166-e167
Keywords blue light; light exposure; light at night; circadian disruption; drowsiness; melatonin; metabolism; sleep
Abstract Introduction

Evening light exposure debilitates the circadian rhythm and elicits sleep disturbance. Blue light peak wavelengths, around 460 nm, suppress melatonin secretion via the non-image-forming system. The effects of nocturnal blue light exposure on sleep have been reported to be specific but rather small (Münch, 2008). This study was designed to assess the effect of nocturnal blue light exposure on sleep and energy metabolism until noon the next day.

Materials and methods

Nine healthy male volunteers aged between 21 and 25 participated in this study which had a balanced cross-over design with intrasubject comparisons. After 2 h dark adaptation, the subjects were exposed to blue light or no light for 2 h. The peak wavelength of the blue LED was 465 nm, and the horizontal irradiance of the blue light at the height of eye was at 7.02fÊW/cm2. Sleep was recorded polysomnographically, and energy metabolism was measured with a whole body indirect calorimeter.

Results

There were no significant differences in sleep architecture and energy metabolism during the night. However, dozing (stages 1 and 2) was significantly higher (26.0 < 29.4 vs 6.3 < 8.1 min, P < 0.05), and energy expenditure, O2 consumption, CO2 production and the thermic effect of food (increase in energy expenditure after breakfast) were significantly lower the following morning in the blue light exposure subjects.

Conclusion

Contrary to our expectation, sleep architecture and energy metabolism during sleep were not affected by evening exposure to blue light. It might be due to our milder intervention by which subjects in a sitting position did not gaze at the light source set on the ceiling, while the subjects in previous studies directly received brighter light via custom built goggles (Cajochen, 2005; Münch, 2008) or gazed at a light source under the influence of mydriatic agents to dilate pupils (Brainard, 2001). New findings of the present study were that dozing (stages 1 and 2) was significantly increased, and energy metabolism was significantly lower the following morning in blue light exposed subjects. This suggests that modulation of the circadian rhythm is affected by nocturnal blue light exposure and the effect continues in the following daytime even if the intervention was mild.
Address University of Tsukuba, Graduate School of Comprehensive Human Sciences, Japan
Corporate Author Thesis
Publisher Place of Publication Editor
Language (up) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1389-9457 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 349
Permanent link to this record
 

 
Author Lin, Y.; Liu, Y.; Sun, Y.; Zhu, X.; Lai, J.; Heynderickx, I.
Title Model predicting discomfort glare caused by LED road lights Type Journal Article
Year 2014 Publication Optics Express Abbreviated Journal Opt. Express
Volume 22 Issue 15 Pages 18056
Keywords LED; LED lighting; glare; road safety; traffic
Abstract To model discomfort glare from LED road lighting, the effect of four key variables on perceived glare was explored. These variables were: the average glare source luminance (Lg), the background luminance (Lb), the solid angle of the glare source from the perspective of the viewer; and the angle between the glare source and the line of sight. Based on these four variables 72 different light conditions were simulated in a scaled experimental set-up. Participants were requested to judge the perceived discomfort glare of these light conditions using the deBoer rating scale. All four variables and some of their interactions had indeed a significant effect on the deBoer rating. Based on these findings, we developed a model, and tested its general applicability in various verification experiments, including laboratory conditions as well as real road conditions. This verification proved the validity of the model with a correlation between measured and predicted values as high as 0.87 and a residual deviation of about 1 unit on the deBoer rating scale. These results filled the gap in estimating discomfort glare of LED road lighting and clarified similarities of and differences in discomfort glare between LED and traditional light sources.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language (up) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1094-4087 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 351
Permanent link to this record
 

 
Author Dunnett, O,
Title Contested landscapes: the moral geographies of light pollution in Britain Type Journal Article
Year 2014 Publication Cultural Geographies Abbreviated Journal Cultural Geographies
Volume 22 Issue 4 Pages 619-636
Keywords Light pollution; geography; darkness; moral geographies; urbanization
Abstract This paper considers the concept of light pollution and its connections to moral geographies of landscape in Britain. The paper aims to provide a greater understanding of light pollution in the present day, where the issue connects to policy debates about energy efficiency, crime, health, ecology and night time aesthetics, whilst also engaging with new areas of research in cultural geography. The main sources of investigation are the Campaign to Protect Rural England and the British Astronomical Association’s Campaign for Dark Skies (est. 1990). Using interviews, archival and textual analysis, the paper examines this anti-light-pollution lobby, looking at the lead-up to the formation of the Campaign as well as its ongoing influence. A moral geography of light pollution is identified, drawing on two interconnected discourses – a notion of the ‘astronomical sublime’ and the problem of urbanization. Whilst the former is often invoked, both through visual and linguistic means, by anti-light pollution campaigners, the latter is characterized as a threat to clear night skies, echoing earlier protests against urban sprawl. Complementing a growing area of research, the geographies of light and darkness, this paper considers the light pollution lobby as a way of investigating the fundamental relationship between humankind and the cosmos in the modern age.
Address School of Geography, Archaeology and Palaeoecology, Elmwood Avenue, Belfast BT7 1NN, UK
Corporate Author Thesis
Publisher SAGE Place of Publication Editor
Language (up) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 353
Permanent link to this record
 

 
Author Gallaway, T.
Title On Light Pollution, Passive Pleasures, and the Instrumental Value of Beauty Type Journal Article
Year 2010 Publication Journal of Economic Issues Abbreviated Journal Journal of Economic Issues
Volume 44 Issue 1 Pages 71-88
Keywords ecomonics; skyglow
Abstract The night sky is a unique and exquisitely valuable cultural asset that is being lost to humanity. Light pollution obscures the heavens, interferes with wildlife, and wastes billions of dollars in energy annually. Light pollution can be easily mitigated, but unfortunately, it has gone largely unnoticed as a preventable environmental problem. This paper examines light pollution as well as the value of the night sky. The paper focuses on society's disregard for the loss of a cultural asset that has been a part of art, science, and culture for as long as these things have existed. It argues that the blame lies largely in an inability to articulate adequately the value of natural beauty. It is further argued that such beauty has instrumental value, and the explicit recognition of this value is an important step toward preserving the night sky and other objects of natural beauty.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language (up) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-3624 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number NwU @ megan.albaugh @ Serial 356
Permanent link to this record
 

 
Author Posudin, Y.
Title Measurement of Light Pollution Type Book Chapter
Year 2014 Publication Methods of Measuring Environmental Parameters Abbreviated Journal
Volume Chapter 33 Issue Pages
Keywords Bortle scale; digital photography; light pollution; portable spectrophotometer; sky quality meter; SQM
Abstract Digital photography is based on the conversion of light by sensitive matrix (array of electronic photodetectors) to capture the image which is then digitized and stored as a computer file for further processing and printing. The spectral sensitivity of the cameras is in good agreement with the spectrum of action of the photosensitive hormone melatonin. Digital photography can be used to quantify light pollution acting on the physiology of living organisms. The chapter discusses the principles of spectrophotometry. A portable spectrophotometer for the measurement of light pollution is proposed by Cinzano. It consists of a cooled CCD camera and a small spectrographic head which is equipped with a De Amici prism composed of two external crown prisms and an inner Flint prism. Sky quality meter (SQM) is a portable photometer for measuring sky brightness and for light pollution monitoring. This device collects the light from a wide solid angle.
Address Department of Physics, National University of Life and Environmental Sciences, Ukraine
Corporate Author Thesis
Publisher John Wiley & Sons, Inc. Place of Publication Editor
Language (up) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 359
Permanent link to this record