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Author Skeldon, A.C.; Phillips, A.J.K.; Dijk, D.-J.
Title The effects of self-selected light-dark cycles and social constraints on human sleep and circadian timing: a modeling approach Type Journal Article
Year 2017 Publication Scientific Reports Abbreviated Journal Sci Rep
Volume 7 Issue Pages 45158
Keywords human health, lighting
Abstract Why do we go to sleep late and struggle to wake up on time? Historically, light-dark cycles were dictated by the solar day, but now humans can extend light exposure by switching on artificial lights. We use a mathematical model incorporating effects of light, circadian rhythmicity and sleep homeostasis to provide a quantitative theoretical framework to understand effects of modern patterns of light consumption on the human circadian system. The model shows that without artificial light humans wakeup at dawn. Artificial light delays circadian rhythmicity and preferred sleep timing and compromises synchronisation to the solar day when wake-times are not enforced. When wake-times are enforced by social constraints, such as work or school, artificial light induces a mismatch between sleep timing and circadian rhythmicity ('social jet-lag'). The model implies that developmental changes in sleep homeostasis and circadian amplitude make adolescents particularly sensitive to effects of light consumption. The model predicts that ameliorating social jet-lag is more effectively achieved by reducing evening light consumption than by delaying social constraints, particularly in individuals with slow circadian clocks or when imposed wake-times occur after sunrise. These theory-informed predictions may aid design of interventions to prevent and treat circadian rhythm-sleep disorders and social jet-lag.
Address University of Surrey, Surrey Sleep Research Centre, Guildford, GU2 7XP, UK
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 2045-2322 ISBN Medium
Area Expedition Conference
Notes PMID:28345624 Approved no
Call Number (down) SU @ spitschan @ Serial 1638
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Author Swaminathan, K.; Klerman, E.B.; Phillips, A.J.K.
Title Are Individual Differences in Sleep and Circadian Timing Amplified by Use of Artificial Light Sources? Type Journal Article
Year 2017 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume Issue Pages 748730417699310
Keywords Human Health
Abstract Within the human population, there is large interindividual variability in the timing of sleep and circadian rhythms. This variability has been attributed to individual differences in sleep physiology, circadian physiology, and/or light exposure. Recent experimental evidence suggests that the latter is necessary to evoke large interindividual differences in sleep and circadian timing. We used a validated model of human sleep and circadian physiology to test the hypothesis that intrinsic differences in sleep and circadian timing are amplified by self-selected use of artificial light sources. We tested the model under 2 conditions motivated by an experimental study (Wright et al., 2013): (1) a “natural” light cycle, and (2) a “realistic” light cycle that included attenuation of light due to living indoors when natural light levels are high and use of electric light when natural light levels are low. Within these conditions, we determined the relationship between intrinsic circadian period (within the range of 23.7-24.6 h) and timing of sleep onset, sleep offset, and circadian rhythms. In addition, we simulated a work week, with fixed wake time for 5 days and free sleep times on weekends. Under both conditions, a longer intrinsic period resulted in later sleep and circadian timing. Compared to the natural condition, the realistic condition evoked more than double the variation in sleep timing across the physiological range of intrinsic circadian periods. Model predictions closely matched data from the experimental study. We found that if the intrinsic circadian period was long (>24.2 h) under the realistic condition, there was significant mismatch in sleep timing between weekdays and weekends, which is known as social jetlag. These findings indicate that individual tendencies to have very delayed schedules can be greatly amplified by self-selected modifications to the natural light/dark cycle. This has important implications for therapeutic treatment of advanced or delayed sleep phase disorders.
Address School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
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 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:28367676 Approved no
Call Number (down) SU @ spitschan @ Serial 1648
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Author Price, L.L.A.; Lyachev, A.; Khazova, M.
Title Optical performance characterization of light-logging actigraphy dosimeters Type Journal Article
Year 2017 Publication Journal of the Optical Society of America. A, Optics, Image Science, and Vision Abbreviated Journal J Opt Soc Am A Opt Image Sci Vis
Volume 34 Issue 4 Pages 545-557
Keywords Human Health, Lighting
Abstract There are several wearable products specially developed or marketed for studying sleep, circadian rhythms, and light levels. However, new recommendations relating to human physiological responses to light have changed what measurements researchers may demand. The performances of 11 light-logging dosimeters from eight manufacturers were compared. The directional and spectral sensitivities, linearity, dynamic range, and resolution were tested for seven models, and compared along with other published data. The sample mainly comprised light-logging actigraphy dosimeters wearable as badges, in accordance with measurement protocols for larger-scale field studies. A proposed standard for optical performance assessments is set out.
Address
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 1084-7529 ISBN Medium
Area Expedition Conference
Notes PMID:28375324 Approved no
Call Number (down) SU @ spitschan @ Serial 1649
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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 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 (down) NwU @ megan.albaugh @ Serial 356
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Author Wang, J., Zhang, J., Gong, L., Li, Q., Zhou, D.
Title Seismic Indirect Economic Loss Assessment and Recovery Evaluation Using Night-time Light Images – Application for Wenchuan Earthquake Type Journal Article
Year 2018 Publication Natural Hazards and Earth System Sciences Abbreviated Journal
Volume In press Issue Pages
Keywords Remote Sensing; Economics
Abstract Seismic indirect economic loss not only has a major impact on regional economic recovery policies, but also related to the economic assistance at the national level. Due to the Cross-regional economic activities and the difficulty of obtaining data, it's difficult that the indirect economic loss survey covers all economic activities. However, night-time light in an area can reflect the economic activity of the region. This paper focuses on the indirect economic losses caused by the Wenchuan earthquake in 2008 and evaluated the progress of restoration and reconstruction based on night-time light Images. First, the functional relationship between GDP and night-time light parameters was established based on the pre-earthquake data. Next, the indirect loss of the earthquake was evaluated by the night-time light attenuation in the disaster area after the earthquake. Then, the capacity recovery, which is characterized by the brightness recovery process of the light area, was evaluated. Lastly, the process of light expansion in the disaster area was analyzed to evaluate the economic expansion speed and efficiency.
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 Medium
Area Expedition Conference
Notes Approved no
Call Number (down) NC @ ehyde3 @ Serial 2064
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