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Author Foster, R.G.; Hughes, S.; Peirson, S.N.
Title (up) Circadian Photoentrainment in Mice and Humans Type Journal Article
Year 2020 Publication Biology Abbreviated Journal Biology (Basel)
Volume 9 Issue 7 Pages
Keywords Review; Animals; Human Health; circadian; entrainment; human; melanopsin (OPN4); mouse; photoreceptor
Abstract Light around twilight provides the primary entrainment signal for circadian rhythms. Here we review the mechanisms and responses of the mouse and human circadian systems to light. Both utilize a network of photosensitive retinal ganglion cells (pRGCs) expressing the photopigment melanopsin (OPN4). In both species action spectra and functional expression of OPN4 in vitro show that melanopsin has a lambdamax close to 480 nm. Anatomical findings demonstrate that there are multiple pRGC sub-types, with some evidence in mice, but little in humans, regarding their roles in regulating physiology and behavior. Studies in mice, non-human primates and humans, show that rods and cones project to and can modulate the light responses of pRGCs. Such an integration of signals enables the rods to detect dim light, the cones to detect higher light intensities and the integration of intermittent light exposure, whilst melanopsin measures bright light over extended periods of time. Although photoreceptor mechanisms are similar, sensitivity thresholds differ markedly between mice and humans. Mice can entrain to light at approximately 1 lux for a few minutes, whilst humans require light at high irradiance (>100's lux) and of a long duration (>30 min). The basis for this difference remains unclear. As our retinal light exposure is highly dynamic, and because photoreceptor interactions are complex and difficult to model, attempts to develop evidence-based lighting to enhance human circadian entrainment are very challenging. A way forward will be to define human circadian responses to artificial and natural light in the “real world” where light intensity, duration, spectral quality, time of day, light history and age can each be assessed.
Address Sleep & Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Sir William Dunn School of Pathology, Oxford Molecular Pathology Institute, South Parks Road, University of Oxford, Oxford OX1 3RF, 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 2079-7737 ISBN Medium
Area Expedition Conference
Notes PMID:32708259; PMCID:PMC7408241 Approved no
Call Number GFZ @ kyba @ Serial 3082
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Author Moore-Ede, M.; Heitmann, A.; Guttkuhn, R.
Title (up) Circadian Potency Spectrum with Extended Exposure to Polychromatic White LED Light under Workplace Conditions Type Journal Article
Year 2020 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume in press Issue Pages in press
Keywords Human Health; circadian; human; light spectrum; melatonin; spectral sensitivity
Abstract Electric light has enabled humans to conquer the night, but light exposure at night can disrupt the circadian timing system and is associated with a diverse range of health disorders. To provide adequate lighting for visual tasks without disrupting the human circadian timing system, a precise definition of circadian spectral sensitivity is required. Prior attempts to define the circadian spectral sensitivity curve have used short (</=90-min) monochromatic light exposures in dark-adapted human subjects or in vitro dark-adapted isolated retina or melanopsin. Several lines of evidence suggest that these dark-adapted circadian spectral sensitivity curves, in addition to 430- to 499-nm (blue) wavelength sensitivity, may include transient 400- to 429-nm (violet) and 500- to 560-nm (green) components mediated by cone- and rod-originated extrinsic inputs to intrinsically photosensitive retinal ganglion cells (ipRGCs), which decay over the first 2 h of extended light exposure. To test the hypothesis that the human circadian spectral sensitivity in light-adapted conditions may have a narrower, predominantly blue, sensitivity, we used 12-h continuous exposures of light-adapted healthy human subjects to 6 polychromatic white light-emitting diode (LED) light sources with diverse spectral power distributions at recommended workplace levels of illumination (540 lux) to determine their effect on the area under curve of the overnight (2000-0800 h) salivary melatonin. We derived a narrow steady-state human Circadian Potency spectral sensitivity curve with a peak at 477 nm and a full-width half-maximum of 438 to 493 nm. This light-adapted Circadian Potency spectral sensitivity permits the development of spectrally engineered LED light sources to minimize circadian disruption and address the health risks of light exposure at night in our 24/7 society, by alternating between daytime circadian stimulatory white light spectra and nocturnal circadian protective white light spectra.
Address Data Analytics Department, Circadian Technologies, Inc., Stoneham, Massachusetts
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:32539484 Approved no
Call Number GFZ @ kyba @ Serial 3010
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Author Leung, J.M.; Martinez, M.E.
Title (up) Circadian Rhythms in Environmental Health Sciences Type Journal Article
Year 2020 Publication Current Environmental Health Reports Abbreviated Journal Curr Environ Health Rep
Volume in press Issue Pages
Keywords Review; Human Health; Asthma; Biomarkers; Breast cancer; Circadian rhythms; DNA methylation; Environmental health
Abstract PURPOSE OF REVIEW: This review aims to explore how circadian rhythms influence disease susceptibility and potentially modify the effect of environmental exposures. We aimed to identify biomarkers commonly used in environmental health research that have also been the subject of chronobiology studies, in order to review circadian rhythms of relevance to environmental health and determine if time-of-day is an important factor to consider in environmental health studies. Moreover, we discuss opportunities for studying how environmental exposures may interact with circadian rhythms to structure disease pathology and etiology. RECENT FINDINGS: In recent years, the study of circadian rhythms in mammals has flourished. Animal models revealed that all body tissues have circadian rhythms. In humans, circadian rhythms were also shown to exist at multiple levels of organization: molecular, cellular, and physiological processes, including responding to oxidative stress, cell trafficking, and sex hormone production, respectively. Together, these rhythms are an essential component of human physiology and can shape an individual's susceptibility and response to disease. Circadian rhythms are relatively unexplored in environmental health research. However, circadian clocks control many physiological and behavioral processes that impact exposure pathways and disease systems. We believe this review will motivate new studies of (i) the impact of exposures on circadian rhythms, (ii) how circadian rhythms modify the effect of environmental exposures, and (iii) how time-of-day impacts our ability to observe the body's response to exposure.
Address Department of Environmental Health Sciences, Columbia University, 630 West 168th Street, Room 16-421C, New York, NY, USA. mem2352@cumc.columbia.edu
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 2196-5412 ISBN Medium
Area Expedition Conference
Notes PMID:32662059 Approved no
Call Number GFZ @ kyba @ Serial 3055
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Author Puschnig, J.; Wallner, S.; Posch, T.
Title (up) Circalunar variations of the night sky brightness – an FFT perspective on the impact of light pollution Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 492 Issue 2 Pages 2622-2637
Keywords Skyglow; Moonlight
Abstract Circa-monthly activity conducted by moonlight is observed in many species on Earth. Given the vast amount of artificial light at night (ALAN) that pollutes large areas around the globe, the synchronization to the circalunar cycle is often strongly perturbed. Using 2-yr data from a network of 23 photometers (Sky Quality Meters; SQM) in Austria (latitude ∼48°), we quantify how light pollution impacts the recognition of the circalunar periodicity. We do so via frequency analysis of nightly mean sky brightnesses using Fast Fourier Transforms. A very tight linear relation between the mean zenithal night sky brightness (NSB) given in magSQMarcsec−2 and the amplitude of the circalunar signal is found, indicating that for sites with a mean zenithal NSB brighter than 16.5 magSQMarcsec−2 the lunar rhythm practically vanishes. This finding implies that the circalunar rhythm is still detectable (within the broad bandpass of the SQM) at most places around the globe, but its amplitude against the light polluted sky is strongly reduced. We find that the circalunar contrast in zenith is reduced compared to ALAN-free sites by factors of 19 in the state capital of Linz (∼200 000 inhabitants) and 13 in small towns, e.g. Freistadt and Mattighofen, with less than 10 000 inhabitants. Only two of our sites, both situated in national parks (Bodinggraben and Zöblboden), show natural circalunar amplitudes. At our urban sites, we further detect a strong seasonal signal that is linked to the amplification of anthropogenic skyglow during the winter months due to climatological conditions.
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 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2838
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Author Li, S.; Cheng, L.; Liu, X.; Mao, J.; Wu, J.; Li, M.
Title (up) City type-oriented modeling electric power consumption in China using NPP-VIIRS nighttime stable light data Type Journal Article
Year 2019 Publication Energy Abbreviated Journal Energy
Volume 189 Issue Pages 116040
Keywords Energy; Remote Sensing; China; electric power consumption; Night lights; Nighttime light; VIIRS-DNB
Abstract Accelerating urbanization has created tremendous pressure on the global environment and energy supply, making accurate estimates of energy use of great importance. Most current models for estimating electric power consumption (EPC) from nighttime light (NTL) imagery are oversimplified, ignoring influential social and economic factors. Here we propose first classifying cities by economic focus and then separately estimating each category’s EPC using NTL data. We tested this approach using statistical employment data for 198 Chinese cities, 2015 NTL data from the Visible Infrared Imaging Radiometer Suite (VIIRS), and annual electricity consumption statistics. We used cluster analysis of employment by sector to divide the cities into three types (industrial, service, and technology and education), then established a linear regression model for each city's NTL and EPC. Compared with the estimation results before city classification (R2: 0.785), the R2 of the separately modeled service cities and technology and education cities increased to 0.866 and 0.830, respectively. However, the results for industrial cities were less consistent due to their more complex energy consumption structure. In general, using classification before modeling helps reflect factors affecting the relationship between EPC and NTL, making the estimation process more reasonable and improving the accuracy of the results.
Address School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China
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 0360-5442 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2672
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