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Author Mortazavi, S.A.R.; Faraz, M.; Laalpour, S.; Kaveh Ahangar, A.; Eslami, J.; Zarei, S.; Mortazavi, G.; Gheisari, F.; Mortazavi, S.M.J. url  doi
openurl 
  Title Exposure to Blue Light Emitted from Smartphones in an Environment with Dim Light at Night Alters the Reaction Time of University Students Type Journal Article
  Year 2019 Publication Shiraz E-Medical Journal Abbreviated Journal Shiraz E-Med J  
  Volume In Press Issue (down) In Press Pages  
  Keywords Human Health  
  Abstract Background: Substantial evidence now indicates that exposure to visible light at night can be linked to a wide spectrum of disorders ranging from obesity to cancer. More specifically, it has been shown that exposure to short wavelengths in the blue region at night is associated with adverse health effects, such as sleep problems.

Objectives: This study aimed at investigating if exposure to blue light emitted from common smartphones in an environment with dim light at night alters human reaction time.

Methods: Visual reaction time (VRT) of 267 male and female university students were recorded using a simple blind computer-assisted VRT test, respectively. Volunteer university students, who provided their informed consent were randomly divided to two groups of control (N = 126 students) and intervention (N = 141 students). All participants were asked to go to bed at 23:00. Participants in the intervention group were asked to use their smartphones from 23:00 to 24:00 (watching a natural life documentary movie for 60 minutes), while the control group only stayed in bed under low lighting condition, i.e. dim light. Before starting the experiment and after 60 minutes of smartphone use, reaction time was recorded in both groups.

Results: The mean reaction times in the intervention and the control groups before the experiment (23:00) did not show a statistically difference (P = 0.449). The reaction time in the intervention group significantly increased from 412.64 ± 105.60 msec at 23:00 to 441.66 ± 125.78 msec at 24:00 (P = 0.0368) while in the control group, there was no statistically significant difference between the mean reaction times at 23:00 and 24:00.

Conclusions: To the best of the author’s knowledge, this is the first study, which showed that exposure to blue-rich visible light emitted from widely used smartphones increases visual reaction time, which would eventually result in a delay in human responses to different hazards. These findings indicate that people, such as night shift or on call workers, who need to react to stresses rapidly should avoid using their smartphones in a dim light at night.
 
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  ISSN 1735-1391 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2534  
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Author Pike, R; Berry, R openurl 
  Title A Bright Future for the Night Sky Type Magazine Article
  Year 1978 Publication Sky and Telescope Abbreviated Journal  
  Volume 55 Issue (down) February Pages 126  
  Keywords Skyglow  
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  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1549  
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Author Clanton, N.; Gibbons, R.; Garcia, J.; Barber, M. url  doi
openurl 
  Title Seattle LED Adaptive Lighting Study Type Report
  Year 2014 Publication Northwest Energy Efficiency Alliance Abbreviated Journal NEEA  
  Volume Issue (down) E14-286 Pages  
  Keywords Public Safety; Lighting; Planning; Vision  
  Abstract The Northwest Energy Efficiency Alliance (NEEA) and the City of Seattle partnered to evaluate the future of solid state street lighting in the Pacific Northwest with a two-night demonstration in Seattle's Ballard neighborhood in March 2012. The study evaluates the effectiveness of LED streetlights on nighttime driver object detection visibility as function of light source spectral distribution (color temperature in degrees K) and light distribution. Clanton & Associates and VTTI also evaluated adaptive lighting (tuning of streetlights during periods of reduced vehicular and pedestrian activity) at three levels: one hundred percent of full light output, fifty percent of full light output, and twenty-five percent of full light output. The study, led by Clanton & Associates, Continuum Industries, and the VTTI, built upon previous visual performance studies conducted in Anchorage, Alaska; San Diego, California; and San Jose, California. The use of LED technology for city street lighting is becoming more widespread. While these lights are primarily touted for their energy efficiency, the combination of LEDs with advanced control technology, changes to lighting criteria, and a better understanding of human mesopic (low light level) visibility creates an enormous potential for energy savings and improved motorist and pedestrian visibility and safety. Data from these tests support the following statements: LED luminaires with a correlated color temperature of 4100K provide the highest detection distance, including statistically significantly better detection distance when compared to HPS luminaires of higher wattage. The non-uniformity of the lighting on the roadway surface provides a visibility enhancement and greater contrast for visibility. Contrast of objects, both positive and negative, is a better indicator of visibility than is average luminance level. Dimming the LED luminaires to fifty percent of IES RP-8 levels did not significantly reduce object detection distance in dry pavement conditions. Participants perceived dimming of sidewalks as less acceptable than dimming to the same level on the roadway. Asymmetric lighting did reduce glare and performed similarly to the symmetric lighting at the same color temperature (4100K).  
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  Language English Summary Language English Original Title  
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  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1763  
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Author Kyba, C.C.M.; Ruhtz, T.; Fischer, J.; Hölker, F. url  doi
openurl 
  Title Lunar skylight polarization signal polluted by urban lighting Type Journal Article
  Year 2011 Publication Journal of Geophysical Research: Atmospheres Abbreviated Journal J. Geophys. Res.  
  Volume 116 Issue (down) D24 Pages  
  Keywords aeroecology; ecological light pollution; light pollution; moonlight; nocturnal navigation; polarized light  
  Abstract On clear moonlit nights, a band of highly polarized light stretches across the sky at a 90 degree angle from the moon, and it was recently demonstrated that nocturnal organisms are able to navigate based on it. Urban skyglow is believed to be almost unpolarized, and is therefore expected to dilute this unique partially linearly polarized signal. We found that urban skyglow has a greater than expected degree of linear polarization (p = 8.6 ± 0.3%), and confirmed that its presence diminishes the natural lunar polarization signal. We also observed that the degree of linear polarization can be reduced as the moon rises, due to the misalignment between the polarization angles of the skyglow and scattered moonlight. Under near ideal observing conditions, we found that the lunar polarization signal was clearly visible (p = 29.2 ± 0.8%) at a site with minimal light pollution 28 km from Berlin's center, but was reduced (p = 11.3 ± 0.3%) within the city itself. Daytime measurements indicate that without skyglow pwould likely be in excess of 50%. These results indicate that nocturnal animal navigation systems based on perceiving polarized scattered moonlight likely fail to operate properly in highly light-polluted areas, and that future light pollution models must take polarization into account.  
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  ISSN 0148-0227 ISBN Medium  
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  Notes Approved no  
  Call Number IDA @ john @ Serial 21  
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Author Li, C.; Li, G.; Zhu, Y.; Ge, Y.; Kung, H.-te; Wu, Y. url  doi
openurl 
  Title A likelihood-based spatial statistical transformation model (LBSSTM) of regional economic development using DMSP/OLS time series and nighttime light imagery Type Journal Article
  Year 2017 Publication Spatial Statistics Abbreviated Journal Spatial Statistics  
  Volume 21 Issue (down) B Pages 421-439  
  Keywords Remote Sensing  
  Abstract In a regional economy, the central city of a metropolitan area has a radiative effect and an accumulative effect on its surrounding cities. Considering the limitations of traditional data sources (e.g., its subjectivity) and the advantages of nighttime light data, including its objectivity, availability and cyclicity, this paper proposes a likelihood spatial statistical transformation model (LBSSTM) to invert for the gross domestic product (GDP) of the surrounding cities, using time series of Sum of Lights (SOL) data covering the central city and taking advantage of the economic and spatial association between the central city and the surrounding cities within a metropolitan area and the correlation between SOL and GDP. The Wuhan Metropolitan Area is chosen to verify the model using time series analysis and exploratory spatial data analysis (ESDA). The experimental results show the feasibility of the proposed LBSSTM. The prediction accuracy of our model is verified by cross-validation using data from 1998, 2004 and 2011, based on the 3σ rule. This model can quantitatively express the agglomeration and diffusion effect of the central city and reveal the spatial pattern of this effect. The results of this work are potentially useful in making spatio-temporal economic projections and filling in missing data from some regions, as well as gaining a deeper quantitative and spatio-temporal understanding of the laws underlying regional economic development.  
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  Series Volume Series Issue Edition  
  ISSN 2211-6753 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1644  
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