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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 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 (up) 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 Christie, S.; Vincent, A.D.; Li, H.; Frisby, C.L.; Kentish, S.J.; O'Rielly, R.; Wittert, G.A.; Page, A.J.
Title A rotating light cycle promotes weight gain and hepatic lipid storage in mice Type Journal Article
Year 2018 Publication American Journal of Physiology. Gastrointestinal and Liver Physiology Abbreviated Journal Am J Physiol Gastrointest Liver Physiol
Volume in press Issue Pages
Keywords Animals
Abstract Processes involved in regulation of energy balance and intermediary metabolism are aligned to the light-dark cycle. Shift-work and high fat diet (HFD)-induced obesity disrupt circadian rhythmicity and are associated with increased risk of non-alcoholic fatty liver disease (NAFLD). This study aimed to determine the effect of simulating shift work on hepatic lipid accumulation in lean and HFD-mice. C57BL/6 mice fed a standard laboratory diet (SLD) or HFD for 4wks were further allocated to a normal light (NL)-cycle (lights on:0600-1800hr) or rotating light (RL)-cycle (3-days NL and 4-days reversed (lights on:1800-0600hr) repeated) for 8wks. Tissue was collected every 3hrs beginning at 0600hr. HFD-mice gained more weight than SLD-mice, and RL-mice gained more weight than NL-mice. SLD-NL and HFD-NL mice, but not RL-mice, were more active, had higher respiratory quotients and consumed/expended more energy during the dark phase compared to the light phase. Blood glucose and plasma cholesterol and triglyceride concentrations were elevated in HFD and SLD-RL compared to SLD-NL mice. Hepatic glycogen was elevated in HFD compared to SLD-mice. Hepatic triglycerides were elevated in SLD-RL and HFD-mice compared to SLD-NL. Circadian rhythmicity of hepatic acetyl-CoA carboxylase (ACACA) mRNA was phase shifted in SLD-RL and HFD-NL and lost in HFD-RL mice. Hepatic ACACA protein was reduced in SLD-RL and HFD-mice compared to SLD-NL mice. Hepatic adipose triglyceride lipase was elevated in HFD-NL compared to SLD-NL but lower in RL-mice compared to NL-mice irrespective of diet. -Conclusion: A RL-cycle model of shift-work promotes weight gain and hepatic lipid storage even in lean conditions.
Address (up) Adelaide Medical School, University of Adelaide, 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 0193-1857 ISBN Medium
Area Expedition Conference
Notes PMID:30188750 Approved no
Call Number GFZ @ kyba @ Serial 2123
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Author Hoffmann, J.; Palme, R.; Eccard, J.A.
Title Long-term dim light during nighttime changes activity patterns and space use in experimental small mammal populations Type Journal Article
Year 2018 Publication Environmental Pollution Abbreviated Journal Environ Pollut
Volume 238 Issue Pages 844-851
Keywords Animals
Abstract Artificial light at night (ALAN) is spreading worldwide and thereby is increasingly interfering with natural dark-light cycles. Meanwhile, effects of very low intensities of light pollution on animals have rarely been investigated. We explored the effects of low intensity ALAN over seven months in eight experimental bank vole (Myodes glareolus) populations in large grassland enclosures over winter and early breeding season, using LED garden lamps. Initial populations consisted of eight individuals (32 animals per hectare) in enclosures with or without ALAN. We found that bank voles under ALAN experienced changes in daily activity patterns and space use behavior, measured by automated radiotelemetry. There were no differences in survival and body mass, measured with live trapping, and none in levels of fecal glucocorticoid metabolites. Voles in the ALAN treatment showed higher activity at night during half moon, and had larger day ranges during new moon. Thus, even low levels of light pollution as experienced in remote areas or by sky glow can lead to changes in animal behavior and could have consequences for species interactions.
Address (up) Animal Ecology, University of Potsdam, Maulbeerallee 1, 14469, Potsdam, Germany
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 0269-7491 ISBN Medium
Area Expedition Conference
Notes PMID:29627754 Approved no
Call Number GFZ @ kyba @ Serial 1848
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Author Bará, S.; Escofet, J.
Title On lamps, walls, and eyes: The spectral radiance field and the evaluation of light pollution indoors Type Journal Article
Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal J of Quant Spect and Rad Trans
Volume 205 Issue Pages 267-277
Keywords Instrumentation; Light pollution; Artificial light at night; Light field; Radiance field; Radiometry; Photometry
Abstract Light plays a key role in the regulation of different physiological processes, through several visual and non-visual retinal phototransduction channels whose basic features are being unveiled by recent research. The growing body of evidence on the significance of these effects has sparked a renewed interest in the determination of the light field at the entrance pupil of the eye in indoor spaces. Since photic interactions are strongly wavelength-dependent, a significant effort is being devoted to assess the relative merits of the spectra of the different types of light sources available for use at home and in the workplace. The spectral content of the light reaching the observer eyes in indoor spaces, however, does not depend exclusively on the sources: it is partially modulated by the spectral reflectance of the walls and surrounding surfaces, through the multiple reflections of the light beams along all possible paths from the source to the observer. This modulation can modify significantly the non-visual photic inputs that would be produced by the lamps alone, and opens the way for controlling—to a certain extent—the subject's exposure to different regions of the optical spectrum. In this work we evaluate the expected magnitude of this effect and we show that, for factorizable sources, the spectral modulation can be conveniently described in terms of a set of effective filter-like functions that provide useful insights for lighting design and light pollution assessment. The radiance field also provides a suitable bridge between indoor and outdoor light pollution studies.
Address (up) Área de Óptica, Departamento de Física Aplicada, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2163
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Author Bará, S.; Rodríguez-Arós, Á.; Pérez, M.; Tosar, B.; Lima, R.; Sánchez de Miguel, A.; Zamorano, J.
Title Estimating the relative contribution of streetlights, vehicles, and residential lighting to the urban night sky brightness Type Journal Article
Year 2018 Publication Lighting Research & Technology Abbreviated Journal Lighting Res & Tech
Volume Issue October 2018 Pages
Keywords Remote Sensing; traffic; Roadway lighting
Abstract Under stable atmospheric conditions the brightness of the urban sky varies throughout the night following the time course of the anthropogenic emissions of light. Different types of artificial light sources (e.g. streetlights, residential, and vehicle lights) have specific time signatures, and this feature makes it possible to estimate the amount of brightness contributed by each of them. Our approach is based on transforming the time representation of the zenithal night sky brightness into a modal expansion in terms of the time signatures of the different sources of light. The modal coefficients, and hence the absolute and relative contributions of each type of source, can be estimated by means of a linear least squares fit. A practical method for determining the time signatures of different contributing sources is also described, based on wide-field time-lapse photometry of the urban nightscape. Our preliminary results suggest that, besides the dominant streetlight contribution, artificial light leaking out of the windows of residential buildings may account for a significant share of the time-varying part of the zenithal night sky brightness at the measurement locations, whilst the contribution of the vehicle lights seems to be significantly smaller.
Address (up) Área de Óptica, Dept. Física Aplicada, Facultade de Óptica e Optometría, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Galicia, Spain. salva.bara(at)usc.es
Corporate Author Thesis
Publisher SAGE Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-1535 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2052
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