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Author Leise, T.L.; Goldberg, A.; Michael, J.; Montoya, G.; Solow, S.; Molyneux, P.; Vetrivelan, R.; Harrington, M.E.
Title Recurring circadian disruption alters circadian clock sensitivity to resetting Type Journal Article
Year 2018 Publication The European Journal of Neuroscience Abbreviated Journal Eur J Neurosci
Volume in press Issue Pages
Keywords Animals
Abstract A single phase advance of the light:dark (LD) cycle can temporarily disrupt synchrony of neural circadian rhythms within the suprachiasmatic nucleus (SCN) and between the SCN and peripheral tissues. Compounding this, modern life can involve repeated disruptive light conditions. To model chronic disruption to the circadian system, we exposed male mice to more than a month of a 20 h light cycle (LD10:10), which mice typically cannot entrain to. Control animals were housed under LD12:12. We measured locomotor activity and body temperature rhythms in vivo, and rhythms of PER2::LUC bioluminescence in SCN and peripheral tissues ex vivo. Unexpectedly, we discovered strong effects of the time of dissection on circadian phase of PER2::LUC bioluminescent rhythms, which varied across tissues. White adipose tissue was strongly reset by dissection, while thymus phase appeared independent of dissection timing. Prior light exposure impacted the SCN, resulting in strong resetting of SCN phase by dissection for mice housed under LD10:10, and weak phase shifts by time of dissection in SCN from control LD12:12 mice. These findings suggest that exposure to circadian disruption may desynchronize SCN neurons, increasing network sensitivity to perturbations. We propose that tissues with a weakened circadian network, such as the SCN under disruptive light conditions, or with little to no coupling, e.g., some peripheral tissues, will show increased resetting effects. In particular, exposure to light at inconsistent circadian times on a recurring weekly basis disrupts circadian rhythms and alters sensitivity of the SCN neural pacemaker to dissection time. This article is protected by copyright. All rights reserved.
Address Neuroscience Program, Smith College, Northampton, MA, 01063, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language (up) English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-816X ISBN Medium
Area Expedition Conference
Notes PMID:30269396 Approved no
Call Number GFZ @ kyba @ Serial 2036
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Author Kozaki, T.; Hidaka, Y.; Takakura, J.-Y.; Kusano, Y.
Title Suppression of salivary melatonin secretion under 100-Hz flickering and non-flickering blue light Type Journal Article
Year 2018 Publication Journal of Physiological Anthropology Abbreviated Journal J Physiol Anthropol
Volume 37 Issue 1 Pages 23
Keywords Human Health
Abstract BACKGROUND: Bright light at night is known to suppress melatonin secretion. Novel photoreceptors named intrinsically photosensitive retinal ganglion cells (ipRGCs) are mainly responsible for projecting dark/bright information to the suprachiasmatic nucleus and thus regulating the circadian system. However, it has been shown that the amplitude of the electroretinogram of ipRGCs is considerably lower under flickering light at 100 Hz than at 1-5 Hz, suggesting that flickering light may also affect the circadian system. Therefore, in this study, we evaluated light-induced melatonin suppression under flickering and non-flickering light. METHODS: Twelve male participants between the ages of 20 and 23 years (mean +/- S.D. = 21.6 +/- 1.5 years) were exposed to three light conditions (dim, 100-Hz flickering, and non-flickering blue light) from 1:00 A.M. to 2:30 A.M., and saliva samples were obtained just before 1:00 A.M. and at 1:15, 1:30, 2:00, and 2:30 A.M. RESULTS: A repeated measures t test with Bonferroni correction showed that at 1:15 A.M., melatonin concentrations were significantly lower following exposure to non-flickering light compared with dim light, whereas there was no significant difference between the dim and 100-Hz flickering light conditions. By contrast, after 1:30 A.M., the mean melatonin concentrations were significantly lower under both 100-Hz flickering and non-flickering light than under dim light. CONCLUSION: Although melatonin suppression rate tended to be lower under 100-Hz flickering light than under non-flickering light at the initial 15 min of the light exposure, the present study suggests that 100-Hz flickering light may have the same impact on melatonin secretion as non-flickering light.
Address Department of Health and Nutrition Sciences, Nishikyushu University, Kanzaki, Japan
Corporate Author Thesis
Publisher Place of Publication Editor
Language (up) English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1880-6791 ISBN Medium
Area Expedition Conference
Notes PMID:30340620 Approved no
Call Number GFZ @ kyba @ Serial 2039
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Author Pulgar, J.; Zeballos, D.; Vargas, J.; Aldana, M.; Manriquez, P.; Manriquez, K.; Quijon, P.A.; Widdicombe, S.; Anguita, C.; Quintanilla, D.; Duarte, C.
Title Endogenous cycles, activity patterns and energy expenditure of an intertidal fish is modified by artificial light pollution at night (ALAN) Type Journal Article
Year 2018 Publication Environmental Pollution (Barking, Essex : 1987) Abbreviated Journal Environ Pollut
Volume 244 Issue Pages 361-366
Keywords Animals
Abstract The increase of global light emissions in recent years has highlighted the need for urgent evaluation of their impacts on the behaviour, ecology and physiology of organisms. Numerous species exhibit daily cycles or strong scototaxic behaviours that could potentially be influenced if natural lighting conditions or cycles are disrupted. Artificial Light Pollution at Night (ALAN) stands for situations where artificial light alters natural light-dark cycles, as well as light intensities and wavelengths. ALAN is increasingly recognized as a potential threat to biodiversity, mainly because a growing number of studies are demonstrating its influence on animal behaviour, migration, reproduction and biological interactions. Most of these studies have focused on terrestrial organisms and ecosystems with studies on the effects of ALAN on marine ecosystems being more occasional. However, with the increasing human use and development of the coastal zone, organisms that inhabit shallow coastal or intertidal systems could be at increasing risk from ALAN. In this study we measured the levels of artificial light intensity in the field and used these levels to conduct experimental trials to determine the impact of ALAN on an intertidal fish. Specifically, we measured ALAN effects on physiological performance (oxygen consumption) and behaviour (activity patterns) of “Baunco” the rockfish Girella laevifrons, one of the most abundant and ecologically important intertidal fish in the Southeastern Pacific littoral. Our results indicated that individuals exposed to ALAN exhibited increased oxygen consumption and activity when compared with control animals. Moreover, those fish exposed to ALAN stopped displaying the natural (circatidal and circadian) activity cycles that were observed in control fish throughout the experiment. These changes in physiological function and behaviour could have serious implications for the long-term sustainability of fish populations and indirect impacts on intertidal communities in areas affected by ALAN.
Address Departamento de Ecologia & Biodiversidad, Facultad de Ciencia de la Vida, Universidad Andres Bello, Chile; Center for the Study of Multiple-Drivers on Marine Socio-Ecological Systems (MUSELS), Universidad de Concepcion, Concepcion, Chile
Corporate Author Thesis
Publisher Place of Publication Editor
Language (up) 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:30352350 Approved no
Call Number GFZ @ kyba @ Serial 2043
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Author Gaston, M.S.; Pereyra, L.C.; Vaira, M.
Title Artificial light at night and captivity induces differential effects on leukocyte profile, body condition, and erythrocyte size of a diurnal toad Type Journal Article
Year 2018 Publication Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology Abbreviated Journal J Exp Zool A Ecol Integr Physiol
Volume in press Issue Pages
Keywords Animals; Amphibians; Toads
Abstract Light pollution or artificial lighting at night (ALAN) is an emerging threat to biodiversity that can disrupt physiological processes and behaviors. Because ALAN stressful effects are little studied in diurnal amphibian species, we investigated if chronic ALAN exposure affects the leukocyte profile, body condition, and blood cell sizes of a diurnal toad. We hand-captured male toads of Melanophryniscus rubriventris in Angosto de Jaire (Jujuy, Argentina). We prepared blood smears from three groups of toads: “field” (toads processed in the field immediately after capture), “natural light” (toads kept in the laboratory under captivity with natural photoperiod), and “constant light” (toads kept in the laboratory under captivity with constant photoperiod/ALAN). We significantly observed higher neutrophil proportions and neutrophils to lymphocytes ratio in toads under constant light treatment. In addition, we observed significantly better body condition and higher erythrocyte size in field toads compared with captive toads. In summary, ALAN can trigger a leukocyte response to stress in males of the diurnal toad M. rubriventris. In addition, captivity can affect the body condition and erythrocyte size of these toads.
Address Instituto de Ecorregiones Andinas (INECOA), Universidad Nacional de Jujuy, CONICET, San Salvador de Jujuy, Argentina
Corporate Author Thesis
Publisher Place of Publication Editor
Language (up) English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2471-5638 ISBN Medium
Area Expedition Conference
Notes PMID:30320969 Approved no
Call Number GFZ @ kyba @ Serial 2049
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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 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 (up) 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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