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Author Bará, S.
Title 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 (down) 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 Sloane, P.D.; Williams, C.S.; Mitchell, C.M.; Preisser, J.S.; Wood, W.; Barrick, A.L.; Hickman, S.E.; Gill, K.S.; Connell, B.R.; Edinger, J.; Zimmerman, S.
Title High-intensity environmental light in dementia: effect on sleep and activity Type Journal Article
Year 2007 Publication Journal of the American Geriatrics Society Abbreviated Journal J Am Geriatr Soc
Volume 55 Issue 10 Pages 1524-1533
Keywords Human Health
Abstract OBJECTIVES: To determine whether high-intensity ambient light in public areas of long-term care facilities will improve sleeping patterns and circadian rhythms of persons with dementia. DESIGN: A cluster-unit crossover intervention trial involving four conditions: morning bright light, evening bright light, all-day bright light, and minimum standard light. SETTING: The common areas of two geriatric units in a psychiatric hospital and a dementia-specific residential care facility. PARTICIPANTS: Sixty-six older adults with dementia. INTERVENTION: Ambient bright light of approximately 2,500 lux, delivered through a low-glare lighting system installed in the dining and activity areas. Participant exposure averaged 2.5 to 3.0 hours for the morning and evening interventions and 8.4 hours for the all-day intervention. MEASUREMENTS: Nighttime sleep using wrist actigraphy and daytime activity using nonobtrusive daytime observations. RESULTS: Night-time sleep increased significantly in participants exposed to morning and all-day light, with the increase most prominent in participants with severe or very severe dementia (mean increase 16 minutes (P=.008) for morning, and 14 minutes (P=.01) for all-day). Morning light produced a mean phase advance of 29 minutes (P=.02) and evening light a mean phase delay of 15 minutes (P=.06). Effects on daytime sleepiness were inconsistent, and the number of sleep bouts, mesor, amplitude, intradaily variability, and interdaily stability were not significantly different, indicating that the overall strength of day and night activity rhythms did not change significantly under any treatment condition. CONCLUSION: Bright light appears to have a modest but measurable effect on sleep in this population, and ambient light may be preferable to stationary devices such as light boxes.
Address Department of Family Medicine, School of Medicine; Cecil G.Sheps Center for Health Services Research, University of North Carolina, Chapel Hill, NC, USA. psloane@med.unc.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language (down) English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-8614 ISBN Medium
Area Expedition Conference
Notes PMID:17714459 Approved no
Call Number GFZ @ kyba @ Serial 2168
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Author Sanotra, G.S.; Lund, J.D.; Vestergaard, K.S.
Title Influence of light-dark schedules and stocking density on behaviour, risk of leg problems and occurrence of chronic fear in broilers Type Journal Article
Year 2002 Publication British Poultry Science Abbreviated Journal Br Poult Sci
Volume 43 Issue 3 Pages 344-354
Keywords Animals
Abstract 1. The aims of this study were to determine (1) the effect of light-dark schedules on the walking ability, the risk of tibial dyschondroplasia (TD) as well as the duration of tonic immobility (TI) reactions in commercial broiler flocks and (2) the effect of a daily dark period and reduced density on the behaviour of broiler chickens. 2. Experiment 1. Group 1 had a 2 to 8 h daily dark period from 2 to 26 d of age (light-dark programme A) at a stocking density of 28.4 chicks/m2. Group 2 had 8 h of darkness daily from 2 to 38 d of age (light-dark programme B) at 24 chicks/m2. The control group had 24 h continuous light at 28.4 chicks/m2. 3. Experiment 2. Behaviour was studied with and without a daily 8 h dark period and at high (30 chicks/m2) and low (18 chicks/m2) stocking densities. 4. Programme B reduced the prevalence of impaired walking ability, corresponding to gait score > 2, when compared with controls. The effect on walking ability corresponding to gait score > 0 approached significance. 5. Both light-dark programmes reduced the occurrence of TD. Programme B (combined with reduced stocking density), however, had the greater effect. 6. Both light-dark programmes reduced the duration of TI, compared with controls (mean = 426 s) Programme B resulted in a larger reduction (alpha = -156.9 s) than programme A (alpha = -117.0). 7. The proportions of chicks drinking, eating, pecking, scratching, standing and performing vertical wing-shakes increased--both when the 8 h dark period and the reduced stocking density were applied separately and in combination (experiment 2). 8. For all behaviours, except standing, the effect of the dark period was largest in broilers kept at the high stocking density (d 40).
Address Department of Animal Science and Animal Health, Division of Ethology and Health, Royal Veterinary and Agricultural University, Groennegaardsvej 8, DK-1870 Frederiksberg C, Copenhagen, Denmark. sgs@kvl.dk
Corporate Author Thesis
Publisher Place of Publication Editor
Language (down) English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0007-1668 ISBN Medium
Area Expedition Conference
Notes PMID:12195793 Approved no
Call Number GFZ @ kyba @ Serial 2169
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Author Manríquez, P.H.; Jara, M.E.; Diaz, M.I.; Quijón, P.A.; Widdicombe, S.; Pulgar, J.; Manríquez, K.; Quintanilla-Ahumada, D.; Duarte, C.
Title Artificial light pollution influences behavioral and physiological traits in a keystone predator species, Concholepas concholepas Type Journal Article
Year 2019 Publication Science of The Total Environment Abbreviated Journal Science of The Total Environment
Volume 661 Issue Pages 543-552
Keywords Animals; Concholepas concholepas; sea snails; mollusks; Muricidae
Abstract Artificial Light At Night (ALAN) is an increasing global problem that, despite being widely recognized in terrestrial systems, has been studied much less in marine habitats. In this study we investigated the effect of ALAN on behavioral and physiological traits of Concholepas concholepas, an important keystone species of the south-eastern Pacific coast. We used juveniles collected in intertidal habitats that had not previously been exposed to ALAN. In the laboratory we exposed them to two treatments: darkness and white LED (Lighting Emitting Diodes) to test for the impacts of ALAN on prey-searching behavior, self-righting time and metabolism. In the field, the distribution of juveniles was observed during daylight-hours to determine whether C. concholepas preferred shaded or illuminated microhabitats. Moreover, we compared the abundance of juveniles collected during day- and night-time hours. The laboratory experiments demonstrated that juveniles of C. concholepas seek out and choose their prey more efficiently in darkened areas. White LED illuminated conditions increased righting times and metabolism. Field surveys indicated that, during daylight hours, juveniles were more abundant in shaded micro-habitats than in illuminated ones. However, during darkness hours, individuals were not seen to aggregate in any particular microhabitats. We conclude that the exposure to ALAN might disrupt important behavioral and physiological traits of small juveniles in this species which, as a mechanism to avoid visual predators, are mainly active at night. It follows that ALAN in coastal areas might modify the entire community structure of intertidal habitats by altering the behavior of this keystone species.
Address Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile; atriciohmanriquez(at)gmail.com
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language (down) English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0048-9697 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2173
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Author Franklin, M.; Chau, K.; Cushing, L.J.; Johnston, J.
Title Characterizing flaring from unconventional oil and gas operations in south Texas using satellite observations Type Journal Article
Year 2019 Publication Environmental Science & Technology Abbreviated Journal Environ Sci Technol
Volume 53 Issue 4 Pages 2220-2228
Keywords Remote Sensing; petroleum; Texas; United States; VIIRS-DNB; Eagle Ford Shale; flaring; oil and gas
Abstract Over the past decade, increases in high-volume hydraulic fracturing for oil and gas extraction in the United States have raised concerns with residents living near wells. Flaring, or the combustion of petroleum products into the open atmosphere, is a common practice associated with oil and gas exploration and production, and has been under-examined as a potential source of exposure. We leveraged data from the Visible Infrared Imaging Spectroradiometer (VIIRS) Nightfire satellite product to characterize the extent of flaring in the Eagle Ford Shale region of south Texas, one of the most productive in the nation. Spatiotemporal hierarchical clustering identified flaring sources, and a regression-based approach combining VIIRS information with reported estimates of vented and flared gas from the Railroad Commission of Texas enabled estimation of flared gas volume at each flare. We identified 43,887 distinct oil and gas flares in the study region from 2012-2016, with a peak in activity in 2014 and an estimated 4.5 billion cubic meters of total gas volume flared over the study period. A comparison with well permit data indicated the majority of flares were associated with oil-producing (82%) and horizontally-drilled (92%) wells. Of the 49 counties in the region, 5 accounted for 71% of the total flaring. Our results suggest flaring may be a significant environmental exposure in parts of this region.
Address Department of Preventive Medicine, University of Southern California, Los Angeles California 90032, United States; meredith.franklin(at)usc.edu
Corporate Author Thesis
Publisher ACS Place of Publication Editor
Language (down) English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-936X ISBN Medium
Area Expedition Conference
Notes PMID:30657671 Approved no
Call Number GFZ @ kyba @ Serial 2175
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