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Author Mouland, J.W.; Martial, F.; Watson, A.; Lucas, R.J.; Brown, T.M.
Title Cones Support Alignment to an Inconsistent World by Suppressing Mouse Circadian Responses to the Blue Colors Associated with Twilight Type Journal Article
Year 2019 Publication Current Biology Abbreviated Journal Current Biology
Volume 29 Issue 24 Pages (down) 4260-4267.e4
Keywords Animals; Circadian Rhythm; mouse models; cones
Abstract In humans, short-wavelength light evokes larger circadian responses than longer wavelengths. This reflects the fact that melanopsin, a key contributor to circadian assessments of light intensity, most efficiently captures photons around 480 nm and gives rise to the popular view that ‘‘blue’’ light exerts the strongest effects on the clock. However, in the natural world, there is often no direct correlation be- tween perceived color (as reported by the cone-based visual system) and melanopsin excitation. Accordingly, although the mammalian clock does receive cone-based chromatic signals, the influence of color on circadian responses to light remains unclear. Here, we define the nature and functional significance of chromatic influences on the mouse circadian sys- tem. Using polychromatic lighting and mice with altered cone spectral sensitivity (Opn1mwR), we generate conditions that differ in color (i.e., ratio of L- to S-cone opsin activation) while providing identical melanopsin and rod activation. When biased toward S-opsin activation (appearing ‘‘blue’’), these stimuli reliably produce weaker circadian behavioral responses than those favoring L-opsin (‘‘yellow’’). This influence of color (which is absent in animals lacking cone phototransduction; Cnga3/) aligns with natural changes in spectral composition over twilight, where decreasing solar angle is accompanied by a strong blue shift. Accordingly, we find that naturalistic color changes support circadian alignment when environmental conditions render diurnal variations in light intensity weak/ambiguous sources of timing information. Our data thus establish how color contributes to circadian entrainment in mammals and provide important new insight to inform the design of lighting environments that benefit health.
Address Centre for Biological Timing, Faculty of Biology, Medicine & Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK; timothy.brown(at)manchester.ac.uk
Corporate Author Thesis
Publisher Cell Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-9822 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2785
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Author Ayalon, I.; de Barros Marangoni, L.F.; Benichou, J.I.C.; Avisar, D.; Levy, O.
Title Red Sea corals under Artificial Light Pollution at Night (ALAN) undergo oxidative stress and photosynthetic impairment Type Journal Article
Year 2019 Publication Global Change Biology Abbreviated Journal Glob Chang Biol
Volume 25 Issue 12 Pages (down) 4194-4207
Keywords Animals; *Anthozoa; Coral Reefs; Ecosystem; Indian Ocean; Oxidative Stress; Photosynthesis; Alan; Ros; corals; light pollution; photosynthesis; physiology
Abstract Coral reefs represent the most diverse marine ecosystem on the planet, yet they are undergoing an unprecedented decline due to a combination of increasing global and local stressors. Despite the wealth of research investigating these stressors, Artificial Light Pollution at Night (ALAN) or “ecological light pollution” represents an emerging threat that has received little attention in the context of coral reefs, despite the potential of disrupting the chronobiology, physiology, behavior, and other biological processes of coral reef organisms. Scleractinian corals, the framework builders of coral reefs, depend on lunar illumination cues to synchronize their biological rhythms such as behavior, reproduction and physiology. While, light pollution (POL) may mask and lead de-synchronization of these biological rhythms process. To reveal if ALAN impacts coral physiology, we have studied two coral species, Acropora eurystoma and Pocillopora damicornis, from the Gulf of Eilat/Aqaba, Red Sea, which is undergoing urban development that has led to severe POL at night. Our two experimental design data revealed that corals exposed to ALAN face an oxidative stress condition, show lower photosynthesis performances measured by electron transport rate (ETR), as well as changes in chlorophyll and algae density parameters. Testing different lights such as Blue LED and White LED spectrum showed more extreme impact in comparison to Yellow LEDs on coral physiology. The finding of this work sheds light on the emerging threat of POL and the impacts on the biology and ecology of Scleractinian corals, and will help to formulate specific management implementations to mitigate its potentially harmful impacts.
Address Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
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 1354-1013 ISBN Medium
Area Expedition Conference
Notes PMID:31512309; PMCID:PMC6900201 Approved no
Call Number GFZ @ kyba @ Serial 2809
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Author Bará, S.
Title Characterizing the zenithal night sky brightness in large territories: how many samples per square kilometre are needed? Type Journal Article
Year 2017 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 473 Issue 3 Pages (down) 4164-4173
Keywords Instrumentation; atmospheric effects; light pollution; numerical methods; photometry
Abstract A recurring question arises when trying to characterize, by means of measurements or theoretical calculations, the zenithal night sky brightness throughout a large territory: how many samples per square kilometre are needed? The optimum sampling distance should allow reconstructing, with sufficient accuracy, the continuous zenithal brightness map across the whole region, whilst at the same time avoiding unnecessary and redundant oversampling. This paper attempts to provide some tentative answers to this issue, using two complementary tools: the luminance structure function and the Nyquist–Shannon spatial sampling theorem. The analysis of several regions of the world, based on the data from the New world atlas of artificial night sky brightness, suggests that, as a rule of thumb, about one measurement per square kilometre could be sufficient for determining the zenithal night sky brightness of artificial origin at any point in a region to within ±0.1 magV arcsec–2 (in the root-mean-square sense) of its true value in the Johnson–Cousins V band. The exact reconstruction of the zenithal night sky brightness maps from samples taken at the Nyquist rate seems to be considerably more demanding.
Address 1Departamento de Física Aplicada, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es
Corporate Author Thesis
Publisher Oxford Academic Place of Publication Editor
Language English Summary Language English 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 IDA @ john @ Serial 2164
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Author Eather, R.H.
Title DMSP calibration Type Journal Article
Year 1979 Publication Journal of Geophysical Research: Space Physics Abbreviated Journal J. Geophys. Res.
Volume 84 Issue A8 Pages (down) 4134-4144
Keywords Remote Sensing
Abstract Although DMSP satellite data are widely used, there has been no reliable absolute calibration. Coordinated data with ground‐based photometers allow a calibration curve of film density versus 4728 N2+ intensity to be derived. The DMSP satellites (5C series) record airglow and can detect auroral forms of intensities ≥50 R of 4278 N2+. It is estimated that the 5D series satellites are capable of detecting auroras with ∼25 R of 4278 N2+.
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 0148-0227 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2385
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Author Bará, S.; Tilve, V.; Nievas, M.; Sanchez de Miguel, A.; Zamorano, J.
Title Zernike power spectra of clear and cloudy light-polluted urban night skies Type Journal Article
Year 2015 Publication Applied Optics Abbreviated Journal Appl. Opt.
Volume 54 Issue 13 Pages (down) 4120-4129
Keywords Skyglow; artificial ligh at night; light pollution; Zernike; power spectrum; atmospheric optics; imaging systems; image analysis
Abstract The Zernike power spectra of the all-sky night brightness distributions of clear and cloudy nights are computed using a modal projection approach. The results obtained in the B, V and R Johnson-Cousins' photometric bands during a one-year campaign of observations at a light-polluted urban site show that these spectra can be described by simple power laws with exponents close to -3 for clear nights and -2 for cloudy ones. The second-moment matrices of the Zernike coefficients show relevant correlations between modes. The multiplicative role of the cloud cover, that contributes to a significant increase of the brightness of the urban night sky in comparison with the values obtained in clear nights, is described in the Zernike space.
Address Area de Optica, Dept. Fisica Aplicada. Facultade de Fisica / Facultade de Optica e Optometría Universidade de Santiago de Compostela Campus Sur, E-15782 Santiago de Compostela, Galicia, Spain; salva.bara@usc.es
Corporate Author Thesis
Publisher Optical Society of America Place of Publication Editor
Language English Summary Language English 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 1156
Permanent link to this record