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Author Rahman, S.A.; St Hilaire, M.A.; Gronfier, C.; Chang, A.-M.; Santhi, N.; Czeisler, C.A.; Klerman, E.B.; Lockley, S.W.
Title (down) Functional decoupling of melatonin suppression and circadian phase resetting in humans Type Journal Article
Year 2018 Publication The Journal of Physiology Abbreviated Journal J Physiol
Volume 596 Issue 11 Pages 2147-2157
Keywords Human Health
Abstract KEY POINTS: There is assumed to be a monotonic association between melatonin suppression and circadian phase resetting induced by light exposure. We tested the association between melatonin suppression and phase resetting in humans. Sixteen young healthy participants received nocturnal bright light ( approximately 9500 lux) exposure of continuous or intermittent patterns, and different durations ranging from 12 min to 6.5 h. Intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression. Each and every bright light stimulus in an intermittent exposure pattern induced a similar degree of melatonin suppression, but did not appear to cause an equal magnitude of phase shift. These results suggest that phase shifts and melatonin suppression are functionally independent such that one cannot be used as a proxy measure of the other. ABSTRACT: Continuous experimental light exposures show that, in general, the conditions that produce greater melatonin suppression also produce greater phase shift, leading to the assumption that one can be used as a proxy for the other. We tested this association in 16 healthy individuals who participated in a 9-day inpatient protocol by assessing melatonin suppression and phase resetting in response to a nocturnal light exposure (LE) of different patterns: (i) dim-light control (<3 lux; n = 6) or (ii) two 12-min intermittent bright light pulses (IBL) separated by 36 min of darkness ( approximately 9500 lux; n = 10). We compared these results with historical data from additional LE patterns: (i) dim-light control (<3 lux; n = 11); (ii) single continuous bright light exposure of 12 min (n = 9), 1.0 h (n = 10) or 6.5 h (n = 6); or (iii) an IBL light pattern consisting of six 15-min pulses with 1.0 h dim-light recovery intervals between them during a total of 6.5 h (n = 7). All light exposure groups had significantly greater phase-delay shifts than the dim-light control condition (P < 0.0001). While a monotonic association between melatonin suppression and circadian phase shift was observed, intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression. Each and every IBL stimulus induced a similar degree of melatonin suppression, but did not appear to cause an equal magnitude of phase shift. These results suggest unique specificities in how light-induced phase shifts and melatonin suppression are mediated such that one cannot be used as a proxy measure of the other.
Address Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3751 ISBN Medium
Area Expedition Conference
Notes PMID:29707782 Approved no
Call Number GFZ @ kyba @ Serial 1887
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Author Schuler, L.D.; Schatz, R.; Berweger, C.D.
Title (down) From global radiance to an increased local political awareness of light pollution Type Journal Article
Year 2018 Publication Environmental Science & Policy Abbreviated Journal Environmental Science & Policy
Volume 89 Issue Pages 142-152
Keywords Remote Sensing; Public Safety; Animals
Abstract We present a novel transparent method to analyze measurements of the Suomi NPP (Suomi National Polar-orbiting Partnership) satellite in night vision, into luminous intensity and luminance on the community level, with a special focus to address light planners and non-experts, and for the first time, to further address politicians, decision-makers and law-makers, and governmental agencies. We checked the propagated efficiency of road lighting and its impact on luminous flux, and identified a waste of light emissions in the largest city of Switzerland, Zurich. We looked at security (issues like criminal acts) and found no correlation with communities’ luminous intensity. We assessed road safety (accidents) against local luminance and found no evidence of darkness being more risky when the overall distribution of illuminance on roads is considered. We screened crayfish habitats in the Canton of Zurich against local illuminance and found clear evidence of preferred darkness for the living. Based on this finding, we propose an upper limit for light immissions in the crayfish habitats. These four analyses have been chosen to demonstrate the usefulness of Suomi NPP's coverage in combination with our approach. We could apply it to ecological, social and economical topics. We hope others will follow and we can draw more attention of governments to take action to reduce the light pollution on local levels, like Langnau am Albis of Switzerland has exemplified.
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 1462-9011 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1965
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Author Gonzalez, T.J.; Lu, Y.; Boswell, M.; Boswell, W.; Medrano, G.; Walter, S.; Ellis, S.; Savage, M.; Varga, Z.M.; Lawrence, C.; Sanders, G.; Walter, R.B.
Title (down) Fluorescent light exposure incites acute and prolonged immune responses in Zebrafish (Danio rerio) skin Type Journal Article
Year 2018 Publication Comparative Biochemistry and Physiology. Toxicology & Pharmacology : CBP Abbreviated Journal Comp Biochem Physiol C Toxicol Pharmacol
Volume 208 Issue Pages 87-95
Keywords Animals
Abstract Artificial light produces an emission spectrum that is considerably different than the solar spectrum. Artificial light has been shown to affect various behavior and physiological processes in vertebrates. However, there exists a paucity of data regarding the molecular genetic effects of artificial light exposure. Previous studies showed that one of the commonly used fluorescent light source (FL; 4100K or “cool white”) can affect signaling pathways related to maintenance of circadian rhythm, cell cycle progression, chromosome segregation, and DNA repair/recombination in the skin of male Xiphophorus maculatus. These observations raise questions concerning the kinetics of the FL induced gene expression response, and which biological functions become modulated at various times after light exposure. To address these questions, we exposed zebrafish to 4100K FL and utilized RNASeq to assess gene expression changes in skin at various times (1 to 12h) after FL exposure. We found 4100K FL incites a robust early (1-2h) transcriptional response, followed by a more protracted late response (i.e., 4-12h). The early transcriptional response involves genes associated with cell migration/infiltration and cell proliferation as part of an overall increase in immune function and inflammation. The protracted late transcriptional response occurs within gene sets predicted to maintain and perpetuate the inflammatory response, as well as suppression of lipid, xenobiotic, and melatonin metabolism.
Address Xiphophorus Genetic Stock Center, Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA. Electronic address: RWalter@txstate.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 1532-0456 ISBN Medium
Area Expedition Conference
Notes PMID:28965927 Approved no
Call Number LoNNe @ kyba @ Serial 1740
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Author Bharti, N.; Tatem, A.J.
Title (down) Fluctuations in anthropogenic nighttime lights from satellite imagery for five cities in Niger and Nigeria Type Journal Article
Year 2018 Publication Scientific Data Abbreviated Journal Sci Data
Volume 5 Issue Pages 180256
Keywords Remote Sensing
Abstract Dynamic measures of human populations are critical for global health management but are often overlooked, largely because they are difficult to quantify. Measuring human population dynamics can be prohibitively expensive in under-resourced communities. Satellite imagery can provide measurements of human populations, past and present, to complement public health analyses and interventions. We used anthropogenic illumination from publicly accessible, serial satellite nighttime images as a quantifiable proxy for seasonal population variation in five urban areas in Niger and Nigeria. We identified population fluxes as the mechanistic driver of regional seasonal measles outbreaks. Our data showed 1) urban illumination fluctuated seasonally, 2) corresponding population fluctuations were sufficient to drive seasonal measles outbreaks, and 3) overlooking these fluctuations during vaccination activities resulted in below-target coverage levels, incapable of halting transmission of the virus. We designed immunization solutions capable of achieving above-target coverage of both resident and mobile populations. Here, we provide detailed data on brightness from 2000-2005 for 5 cities in Niger and Nigeria and detailed methodology for application to other populations.
Address WorldPop, Department of Geography and Environment, University of Southampton; Flowminder Foundation, Southampton, SO17 1BJ, 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 2052-4463 ISBN Medium
Area Expedition Conference
Notes PMID:30422123; PMCID:PMC6233255 Approved no
Call Number GFZ @ kyba @ Serial 2769
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Author Petržala, J.
Title (down) Feasibility of inverse problem solution for determination of city emission function from night sky radiance measurements Type Journal Article
Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 213 Issue Pages 86-94
Keywords Skyglow
Abstract The knowledge of the emission function of a city is crucial for simulation of sky glow in its vicinity. The indirect methods to achieve this function from radiances measured over a part of the sky have been recently developed. In principle, such methods represent an ill-posed inverse problem. This paper deals with the theoretical feasibility study of various approaches to solving of given inverse problem. Particularly, it means testing of fitness of various stabilizing functionals within the Tikhonov’s regularization. Further, the L-curve and generalized cross validation methods were investigated as indicators of an optimal regularization parameter. At first, we created the theoretical model for calculation of a sky spectral radiance in the form of a functional of an emission spectral radiance. Consequently, all the mentioned approaches were examined in numerical experiments with synthetical data generated for the fictitious city and loaded by random errors. The results demonstrate that the second order Tikhonov’s regularization method together with regularization parameter choice by the L-curve maximum curvature criterion provide solutions which are in good agreement with the supposed model emission functions.
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 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1868
Permanent link to this record