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Author Bará, S.
Title (up) 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 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 Xie, C.; Zhu, H.; Chen, S.; Wen, Y.; Jin, L.; Zhang, L.; Tong, J.; Shen, Y.
Title (up) Chronic retinal injury induced by white LED light with different correlated color temperatures as determined by microarray analyses of genome-wide expression patterns in mice Type Journal Article
Year 2020 Publication Journal of Photochemistry and Photobiology. B, Biology Abbreviated Journal J Photochem Photobiol B
Volume 210 Issue Pages 111977
Keywords Animals; Vision; Autophagy; Cct; Expression profile microarray; Genome-wide; Led; Retinal photoreceptor degeneration; Ubiquitin
Abstract Widely used white light-emitting diodes (LEDs) currently deliver higher levels of blue light than conventional domestic light sources. The high intensity of the blue component is the main source of concern regarding possible health risks of LED to chronic light toxicity to the retina. Therefore, we analyzed retinal injury and genome-wide changes in gene expression induced by white LED light with different correlated color temperatures (CCTs) in a mouse model. Balb/c mice (10 weeks old) were exposed to LED light with CCTs of 2954, 5624, and 7378 K, at different illuminance levels (250, 500, 1000, and 3000 lx) and for different exposure times (7, 14, and 28 days). Hematoxylin and eosin staining revealed that exposure to 7378 K light at 250 lx for 28 days resulted in a significant reduction of outer nuclear layer (ONL) nuclei, whereas 2954 K light at <3000 lx led to only a mild reduction in the number of ONL nuclei. In addition, 5624 and 7378 K light at 3000 lx resulted in a significant increase in TUNEL-positive apoptotic nuclei, which was not found at an illuminance of 1000 lx. Genome-wide expression analyses showed that, compared to a control group, there were 121 upregulated differentially expressed genes (DEGs) and 458 downregulated DEGs found in the 7378 K group, and 59 upregulated and only 4 downregulated DEGs in the 2954 K group. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the DEGs were involved in 341 GO terms and 16 related pathways for the 7378 K group and in 12 GO terms and 7 related pathways for the 2954 K group. Signal pathways related to ubiquitin potentially played an important role in light-induced retinal degeneration. Furthermore, retinal immunohistochemistry (IHC) indicated downregulation of ubiquitin and autophagy function caused by 7378 K light. Taken together, these results indicate that retinal injury in the mice induced by white LED light occurred in a CCT-dependent manner, and that light with a higher CCT was more likely to reduce ONL nuclei; however, the apoptosis pathway may not be the only mechanism involved. Based on genome-wide expression analyses and retinal IHC, the ubiquitin-mediated proteolysis signal pathway may have participated in the induction retinal degeneration.
Address Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China. Electronic address: idrshen@zju.edu.com
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 1011-1344 ISBN Medium
Area Expedition Conference
Notes PMID:32738749 Approved no
Call Number GFZ @ kyba @ Serial 3086
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Author Porcheret, K.; Wald, L.; Fritschi, L.; Gerkema, M.; Gordijn, M.; Merrrow, M.; Rajaratnam, S.M.W.; Rock, D.; Sletten, T.L.; Warman, G.; Wulff, K.; Roenneberg, T.; Foster, R.G.
Title (up) Chronotype and environmental light exposure in a student population Type Journal Article
Year 2018 Publication Chronobiology International Abbreviated Journal Chronobiol Int
Volume 35 Issue 10 Pages 1365-1374
Keywords Human Health
Abstract In humans and most other species, changes in the intensity and duration of light provide a critical set of signals for the synchronisation of the circadian system to the astronomical day. The timing of activity within the 24 h day defines an individual's chronotype, i.e. morning, intermediate or evening type. The aim of this study was to investigate the associations between environmental light exposure, due to geographical location, on the chronotype of university students. Over 6 000 university students from cities in the Northern Hemisphere (Oxford, Munich and Groningen) and Southern Hemisphere (Perth, Melbourne and Auckland) completed the Munich ChronoType Questionnaire. In parallel, light measures (daily irradiance, timing of sunrise and sunset) were compiled from satellite or ground stations at each of these locations. Our data shows that later mid-sleep point on free days (corrected for oversleep on weekends MFSsc) is associated with (i) residing further from the equator, (ii) a later sunset, (iii) spending more time outside and (iv) waking from sleep significantly after sunrise. However, surprisingly, MSFsc did not correlate with daily light intensity at the different geographical locations. Although these findings appear to contradict earlier studies suggesting that in the wider population increased light exposure is associated with an earlier chronotype, our findings are derived exclusively from a student population aged between 17 and 26 years. We therefore suggest that the age and occupation of our population increase the likelihood that these individuals will experience relatively little light exposure in the morning whilst encountering more light exposure later in the day, when light has a delaying effect upon the circadian system.
Address a Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences , University of Oxford , Oxford , 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 0742-0528 ISBN Medium
Area Expedition Conference
Notes PMID:29913073 Approved no
Call Number GFZ @ kyba @ Serial 1962
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Author Murphy, B.A.
Title (up) Circadian and circannual regulation in the horse: Internal timing in an elite athlete Type Journal Article
Year 2019 Publication Journal of Equine Veterinary Science Abbreviated Journal Journal of Equine Veterinary Science
Volume 76 Issue Pages 14-24
Keywords Animals; Mammals; horses
Abstract Biological rhythms evolved to provide temporal coordination across all tissues and organs and allow synchronisation of physiology with predictable environmental cycles. Most important of these are circadian and circannual rhythms, primarily regulated via photoperiod signals from the retina. Understanding the nature of physiological rhythms in horses is crucially important for equine management. Predominantly, we have removed them from exposure to their natural environmental stimuli; the seasonally changing photoperiod, continuous foraging and feeding activity, social herd interactions and the continuous low intensity exercise of a grassland dweller. These have been replaced in many cases with confined indoor housing, regimental feeding and exercise times, social isolation and exposure to lighting that is often erratic and does not come close to mimicking the spectral composition of sunlight. We have further altered seasonal timing cues through the use of artificial lighting programs that impact reproductive behaviour, breeding efficiency and the development of youngstock. Understanding how these new environmental cues (some stronger, some weaker) impact the internal physiology of the horse in the context of the natural endogenous rhythms that evolved over millennia, is key to helping to improve equine health, welfare and performance, now and into the future. This review provides an overview of the field, highlights the recent discoveries related to biological timing in horses and discusses the implications that these findings may have for the production and management of the elite equine athlete.
Address Barbara A. Murphy, School of Agriculture and Food Science, University College Dublin, Dublin 4, Ireland; Barbara.murphy(at)ucd.ie
Corporate Author Thesis
Publisher Elseverier Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0737-0806 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2257
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Author Jan Stenvers, D.; Scheer, F.A.J.L.; Schrauwen, P.; la Fleur, S.E.; Kalsbeek, A.
Title (up) Circadian clocks and insulin resistance Type Journal Article
Year 2018 Publication Nature Reviews. Endocrinology Abbreviated Journal Nat Rev Endocrinol
Volume in press Issue Pages
Keywords Human Health; Review
Abstract Insulin resistance is a main determinant in the development of type 2 diabetes mellitus and a major cause of morbidity and mortality. The circadian timing system consists of a central brain clock in the hypothalamic suprachiasmatic nucleus and various peripheral tissue clocks. The circadian timing system is responsible for the coordination of many daily processes, including the daily rhythm in human glucose metabolism. The central clock regulates food intake, energy expenditure and whole-body insulin sensitivity, and these actions are further fine-tuned by local peripheral clocks. For instance, the peripheral clock in the gut regulates glucose absorption, peripheral clocks in muscle, adipose tissue and liver regulate local insulin sensitivity, and the peripheral clock in the pancreas regulates insulin secretion. Misalignment between different components of the circadian timing system and daily rhythms of sleep-wake behaviour or food intake as a result of genetic, environmental or behavioural factors might be an important contributor to the development of insulin resistance. Specifically, clock gene mutations, exposure to artificial light-dark cycles, disturbed sleep, shift work and social jet lag are factors that might contribute to circadian disruption. Here, we review the physiological links between circadian clocks, glucose metabolism and insulin sensitivity, and present current evidence for a relationship between circadian disruption and insulin resistance. We conclude by proposing several strategies that aim to use chronobiological knowledge to improve human metabolic health.
Address Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands. a.kalsbeek@nin.knaw.nl
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 1759-5029 ISBN Medium
Area Expedition Conference
Notes PMID:30531917 Approved no
Call Number GFZ @ kyba @ Serial 2133
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