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Author Bará, S.; Aubé, M.; Barentine, J.; Zamorano, J.
Title Magnitude to luminance conversions and visual brightness of the night sky Type Journal Article
Year (down) 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume 493 Issue 2 Pages 2429–2437
Keywords Skyglow; light pollution; atmospheric effects; techniques: photometric; methods: numerical; luminance
Abstract The visual brightness of the night sky is not a single-valued function of its brightness in other photometric bands, because the transformations between photometric systems depend on the spectral power distribution of the skyglow. We analyze the transformation between the night sky brightness in the Johnson-Cousins V band (mV, measured in magnitudes per square arcsecond, mpsas) and its visual luminance (L, in SI units cd m−2) for observers with photopic and scotopic adaptation, in terms of the spectral power distribution of the incident light. We calculate the zero-point luminances for a set of skyglow spectra recorded at different places in the world, including strongly light-polluted locations and sites with nearly pristine natural dark skies. The photopic skyglow luminance corresponding to mV = 0.00 mpsas is found to vary between 1.11–1.34 × 105 cd m−2 if mV is reported in the absolute (AB) magnitude scale, and between 1.18–1.43 × 105 cd m−2 if a Vega scale for mV is used instead. The photopic luminance for mV = 22.0 mpsas is correspondingly comprised between 176 and 213 μcd m−2 (AB), or 187 and 227 μcd m−2 (Vega). These constants tend to decrease for increasing correlated color temperatures (CCT). The photopic zero-point luminances are generally higher than the ones expected for blackbody radiation of comparable CCT. The scotopic-to-photopic luminance ratio (S/P) for our spectral dataset varies from 0.8 to 2.5. Under scotopic adaptation the dependence of the zero-point luminances with the CCT, and their values relative to blackbody radiation, are reversed with respect to photopic ones.
Address Departamento de Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia; salva.bara(at)usc.gal
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2825
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Author Ritonja, J.; McIsaac, M.A.; Sanders, E.; Kyba, C.C.M.; Grundy, A.; Cordina-Duverger, E.; Spinelli, J.J.; Aronson, K.J.
Title Outdoor light at night at residences and breast cancer risk in Canada Type Journal Article
Year (down) 2020 Publication European Journal of Epidemiology Abbreviated Journal Eur J Epidemiol
Volume in press Issue Pages
Keywords Human Health; Breast cancer; Case-control study; Circadian disruption; Light at night; Night work; Women's health
Abstract Experimental and epidemiologic studies suggest that light at night (LAN) exposure disrupts circadian rhythm, and this disruption may increase breast cancer risk. We investigated the potential association between residential outdoor LAN and breast cancer risk. A population-based case-control study was conducted in Vancouver, British Columbia and Kingston, Ontario, Canada with incident breast cancer cases, and controls frequency matched by age in the same region. This analysis was restricted to 844 cases and 905 controls who provided lifetime residential histories. Using time-weighted average duration at each home 5-20 years prior to study entry, two measures of cumulative average outdoor LAN were calculated using two satellite data sources. Logistic regression was used to estimate the relationship between outdoor LAN and breast cancer risk, considering interactions for menopausal status and night shift work. We found no association between residential outdoor LAN and breast cancer for either measure of LAN [OR comparing highest vs. lowest tertile (DNB) = 0.95, 95% CI 0.70-1.27]. We also found no association when considering interactions for menopausal status and past/current night work status. These findings were robust to changes to years of residential data considered, residential mobility, and longer exposure windows. Our findings are consistent with studies reporting that outdoor LAN has a small effect or no effect on breast cancer risk.
Address Division of Cancer Care and Epidemiology, Cancer Research Institute, Queen's University, Kingston, ON, Canada. aronson@queensu.ca
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 0393-2990 ISBN Medium
Area Expedition Conference
Notes PMID:32026169 Approved no
Call Number GFZ @ kyba @ Serial 2826
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Author Kyba, C.C.M.; Conrad, J.; Shatwell, T.
Title Lunar illuminated fraction is a poor proxy for moonlight exposure Type Journal Article
Year (down) 2020 Publication Nature Ecology & Evolution Abbreviated Journal Nat Ecol Evol
Volume 4 Issue Pages 318-319
Keywords Animals; Moonlight; Commentary
Abstract San-Jose et al. recently demonstrated that the colouration of barn owls impacts their hunting success under moonlit conditions, and therefore affects their reproductive success1. They found that near full-moon conditions, the youngest nestlings with white fathers were fed more and were likelier to survive than those with redder fathers. While the study is interesting, the percentage of the Moon that is illuminated (lunar illuminated fraction) is unfortunately a poor proxy for moonlight exposure. We suggest that lunar illluminated fraction should, in general, never be used in biological studies, as alternative variables such as horizontal illuminance better represent moonlight exposure, and therefore offer a greater chance of detecting the effects of moonlight. Here, we provide a brief explanation of how moonlight varies with season and time of night, and stress the need for greater collaboration between biologists and astronomers or physicists in such studies in the future.
Address Seenforschung, Helmholtz-Zentrum fur Umweltforschung-UFZ, Magdeburg, 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 2397-334X ISBN Medium
Area Expedition Conference
Notes PMID:32015523 Approved no
Call Number GFZ @ kyba @ Serial 2827
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Author Yue, F.; Xia, K.; Wei, L.; Xing, L.; Wu, S.; Shi, Y.; Man, L.S.; Shui, G.; Xiang, X.; Russell, R.; Zhang, D.
Title Constant light exposure causes dysregulation of sphingolipids and promotes steatohepatitis in high-fat fed rats Type Journal Article
Year (down) 2020 Publication Journal of Gastroenterology and Hepatology Abbreviated Journal J Gastroenterol Hepatol
Volume in press Issue Pages
Keywords Animals; apoptosis; ceramide; light pollution; non-alcoholic fatty liver disease; sphingolipids
Abstract BACKGROUND AND AIM: Non-alcoholic fatty liver disease (NAFLD) is a growing public health concern worldwide. With the progression of urbanization, light pollution is becoming an inevitable risk factor for NAFLD. However, the role of light pollution on NAFLD is insufficiently understood, and the underlying mechanism remains unclear. The present study explored effects of constant light exposure on NAFLD and elucidated its related mechanisms. METHODS: Thirty-two male SD rats were divided into 4 groups (n=8 each): 1) rats on a normal diet exposed to standard light-dark cycle (ND-LD); 2) rats on a normal diet exposed to constant light (ND-LL); 3) rats on a high fat diet exposed to standard light-dark cycle (HFD-LD); 4) and rats on a high fat diet exposed to constant light (HFD-LL). After 12 weeks treatment, rats were sacrificed and pathophysiological assessments were performed. Targeted lipidomics was used to measure sphingolipids, including ceramides, glucosylceramides and lactosylceramides, sphingomyelins and sphingosine-1-phosphates in plasma and liver tissues. RESULTS: In normal chow rats, constant light exposure led to glucose abnormalities and dyslipidemia. In high-fat fed rats, constant light exposure exacerbated glucose abnormalities, dyslipidemia, insulin resistance, inflammation and aggravated steatohepatitis. Compared to HFD-LD rats, HFD-LL had decreased plasma sphingosine-1-phosphate and elevated liver concentrations of total ceramides and specific ceramide species (ceramide d18:0/24:0, ceramide d18:1/22:0, ceramide d18:1/24:0 and ceramide d18:1/24:1), and which were associated with increased hepatocyte apoptosis. CONCLUSIONS: Constant light exposure causes dysregulation of sphingolipids and promotes steatohepatitis in high-fat fed rats.
Address Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
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 0815-9319 ISBN Medium
Area Expedition Conference
Notes PMID:32027419 Approved no
Call Number GFZ @ kyba @ Serial 2829
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Author Wu, Y.; Jiang, M.; Chang, Z.; Li, Y.; Shi, K.
Title Does China's Urban Development Satisfy Zipf's Law? A Multiscale Perspective from the NPP-VIIRS Nighttime Light Data Type Journal Article
Year (down) 2020 Publication International Journal of Environmental Research and Public Health Abbreviated Journal Int J Environ Res Public Health
Volume 17 Issue 4 Pages
Keywords Remote Sensing; China; Zipf's law; multiscale analysis; nighttime lights; urban development
Abstract Currently, whether the urban development in China satisfies Zipf's law across different scales is still unclear. Thus, this study attempted to explore whether China's urban development satisfies Zipf's law across different scales from the National Polar-Orbiting Partnership's Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) nighttime light data. First, the NPP-VIIRS data were corrected. Then, based on the Zipf law model, the corrected NPP-VIIRS data were used to evaluate China's urban development at multiple scales. The results showed that the corrected NPP-VIIRS data could effectively reflect the state of urban development in China. Additionally, the Zipf index (q) values, which could express the degree of urban development, decreased from 2012 to 2018 overall in all provinces, prefectures, and counties. Since the value of q was relatively close to 1 with an R(2) value > 0.70, the development of the provinces and prefectures was close to the ideal Zipf's law state. In all counties, q > 1 with an R(2) value > 0.70, which showed that the primate county had a relatively stronger monopoly capacity. When the value of q < 1 with a continuous declination in the top 2000 counties, the top 250 prefectures, and the top 20 provinces in equilibrium, there was little difference in the scale of development at the multiscale level with an R(2) > 0.90. The results enriched our understanding of urban development in terms of Zipf's law and had valuable implications for relevant decision-makers and stakeholders.
Address Chongqing Engineering Research Centre for Remote Sensing Big Data Application, School of Geographical Sciences, Southwest University, Chongqing 400715, China
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 1660-4601 ISBN Medium
Area Expedition Conference
Notes PMID:32102480 Approved no
Call Number GFZ @ kyba @ Serial 2832
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