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Author Hart, E.E.; Fennessy, J.; Hauenstein, S.; Ciuti, S.
Title Intensity of giraffe locomotor activity is shaped by solar and lunar zeitgebers Type Journal Article
Year 2020 Publication Behavioural Processes Abbreviated Journal Behav Processes
Volume in press Issue Pages in press
Keywords Moonlight; Animals
Abstract Natural cycles of light and darkness shift the balance of risks and gains for animals across space and time. Entrainment to photic cycles allows animals to spatiotemporally adapt their behavioural and physiological processes in line with interplaying ecological factors, such as temperature, foraging efficiency and predation risk. Until recently, our understanding of these chronobiological processes was limited by the difficulties of 24 hr observations. Technological advances in GPS biotelemetry however are now allowing us unprecedented access to long-term, fine-scale activity data. Here we use data derived from frontline technology to present the first large-scale investigation into the effects of natural fluctuations of light and darkness on the locomotor activity patterns of a threatened African mega-herbivore, the giraffe (Giraffa spp.). Using data from a remote population of Angolan giraffe (G. g. angolensis) in the northern Namib Desert, Namibia, we reveal the first full picture of giraffe chronobiology in a landscape of fear. Furthermore, we present clear evidence of the effect of moonlight on the nocturnal activity patterns of large ungulates. Our results are in line with recent research demonstrating that, rather than a fixed internal representation of time (circadian clock), many surface-dwelling ungulates have plastic activity patterns that are vulnerable to modification by external factors including light and temperature. Relatedly, we highlight important conservation management implications of rising temperatures and increasing light pollution on the chronobiology of surface-dwelling mammals.
Address Laboratory of Wildlife Ecology and Behaviour, School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
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 0376-6357 ISBN Medium
Area Expedition Conference
Notes PMID:32562740 Approved no
Call Number GFZ @ kyba @ Serial (down) 3013
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Author Moore-Ede, M.; Heitmann, A.; Guttkuhn, R.
Title Circadian Potency Spectrum with Extended Exposure to Polychromatic White LED Light under Workplace Conditions Type Journal Article
Year 2020 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume in press Issue Pages in press
Keywords Human Health; circadian; human; light spectrum; melatonin; spectral sensitivity
Abstract Electric light has enabled humans to conquer the night, but light exposure at night can disrupt the circadian timing system and is associated with a diverse range of health disorders. To provide adequate lighting for visual tasks without disrupting the human circadian timing system, a precise definition of circadian spectral sensitivity is required. Prior attempts to define the circadian spectral sensitivity curve have used short (</=90-min) monochromatic light exposures in dark-adapted human subjects or in vitro dark-adapted isolated retina or melanopsin. Several lines of evidence suggest that these dark-adapted circadian spectral sensitivity curves, in addition to 430- to 499-nm (blue) wavelength sensitivity, may include transient 400- to 429-nm (violet) and 500- to 560-nm (green) components mediated by cone- and rod-originated extrinsic inputs to intrinsically photosensitive retinal ganglion cells (ipRGCs), which decay over the first 2 h of extended light exposure. To test the hypothesis that the human circadian spectral sensitivity in light-adapted conditions may have a narrower, predominantly blue, sensitivity, we used 12-h continuous exposures of light-adapted healthy human subjects to 6 polychromatic white light-emitting diode (LED) light sources with diverse spectral power distributions at recommended workplace levels of illumination (540 lux) to determine their effect on the area under curve of the overnight (2000-0800 h) salivary melatonin. We derived a narrow steady-state human Circadian Potency spectral sensitivity curve with a peak at 477 nm and a full-width half-maximum of 438 to 493 nm. This light-adapted Circadian Potency spectral sensitivity permits the development of spectrally engineered LED light sources to minimize circadian disruption and address the health risks of light exposure at night in our 24/7 society, by alternating between daytime circadian stimulatory white light spectra and nocturnal circadian protective white light spectra.
Address Data Analytics Department, Circadian Technologies, Inc., Stoneham, Massachusetts
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 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:32539484 Approved no
Call Number GFZ @ kyba @ Serial (down) 3010
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Author de Meester, J.; Storch, T.
Title Optimized Performance Parameters for Nighttime Multispectral Satellite Imagery to Analyze Lightings in Urban Areas Type Journal Article
Year 2020 Publication Sensors (Basel, Switzerland) Abbreviated Journal Sensors (Basel)
Volume 20 Issue 11 Pages
Keywords Instrumentation; Remote Sensing; high spatial resolution; lighting parameter; lighting type classification; multispectral band optimization; nighttime remote sensing; satellite image simulation; urban area
Abstract Contrary to its daytime counterpart, nighttime visible and near infrared (VIS/NIR) satellite imagery is limited in both spectral and spatial resolution. Nevertheless, the relevance of such systems is unquestioned with applications to, e.g., examine urban areas, derive light pollution, and estimate energy consumption. To determine optimal spectral bands together with required radiometric and spatial resolution, at-sensor radiances are simulated based on combinations of lamp spectra with typical luminances according to lighting standards, surface reflectances, and radiative transfers for the consideration of atmospheric effects. Various band combinations are evaluated for their ability to differentiate between lighting types and to estimate the important lighting parameters: efficacy to produce visible light, percentage of emissions attributable to the blue part of the spectrum, and assessment of the perceived color of radiation sources. The selected bands are located in the green, blue, yellow-orange, near infrared, and red parts of the spectrum and include one panchromatic band. However, these nighttime bands tailored to artificial light emissions differ significantly from the typical daytime bands focusing on surface reflectances. Compared to existing or proposed nighttime or daytime satellites, the recommended characteristics improve, e.g., classification of lighting types by >10%. The simulations illustrate the feasible improvements in nocturnal VIS/NIR remote sensing which will lead to advanced applications.
Address German Aerospace Center (DLR), Earth Observation Center (EOC), Munchener Str. 20, 82234 Wessling, 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 1424-8220 ISBN Medium
Area Expedition Conference
Notes PMID:32532117 Approved no
Call Number GFZ @ kyba @ Serial (down) 3006
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Author Hey, M.H.; DiBiase, E.; Roach, D.A.; Carr, D.E.; Haynes, K.J.
Title Interactions between artificial light at night, soil moisture, and plant density affect the growth of a perennial wildflower Type Journal Article
Year 2020 Publication Oecologia Abbreviated Journal Oecologia
Volume in press Issue Pages
Keywords Plants; Community ecology; Light pollution; Milkweed; Precipitation; Sensory pollution
Abstract Artificial light at night (ALAN) has been shown to alter aspects of plant growth, but we are not aware of any studies that have examined whether the effects of ALAN on plants depend upon the backdrop of variation in other abiotic factors that plants encounter in field populations. We conducted a field experiment to investigate whether ALAN affects the growth and anti-herbivore defenses of common milkweed, Asclepias syriaca, and whether the effects of ALAN are influenced by plant density or soil moisture content. Artificial light at night, soil moisture, and plant density were manipulated according to a split-plot factorial design. Although increasing soil moisture by watering had no significant effects on latex exudation, attributes of plant growth generally responded positively to watering. The basal stem diameter (BSD) and height of plants were affected by ALAN x soil moisture interactions. For both of these variables, the positive effects of ALAN were greater for plants that were not watered than for plants that were. Basal stem diameter was also affected by an ALAN x plant density interaction, and the positive effect of ALAN on BSD was greater in the low-density treatment than in the high-density treatment. Our results demonstrate that the effects of ALAN on plant growth can be altered by soil moisture and plant density. Consequently, the effects of ALAN on plants in nature may not be consistent with existing frameworks that do not account for critical abiotic variables such as water availability or biotic interactions between plants such as competition.
Address Blandy Experimental Farm, University of Virginia, 400 Blandy Farm Lane, Boyce, VA, 22620, USA
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 0029-8549 ISBN Medium
Area Expedition Conference
Notes PMID:32533357 Approved no
Call Number GFZ @ kyba @ Serial (down) 3003
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Author Kolláth, Z.; Cool, A.; Jechow, A.; Kolláth, K.; Száz, D.; Tong, K.P.
Title Introducing the Dark Sky Unit for multi-spectral measurement of the night sky quality with commercial digital cameras Type Journal Article
Year 2020 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume Issue Pages 107162
Keywords Measurement; skyglow; light pollution; Radiometry
Abstract Multi-spectral imaging radiometry of the night sky provides essential information on light pollution (skyglow) and sky quality. However, due to the different spectral sensitivity of the devices used for light pollution measurement, the comparison of different surveys is not always trivial. In addition to the differences between measurement approaches, there is a strong variation in natural sky radiance due to the changes of airglow. Thus, especially at dark locations, the classical measurement methods (such as Sky Quality Meters) fail to provide consistent results. In this paper, we show how to make better use of the multi-spectral capabilities of commercial digital cameras and show their application for airglow analysis. We further recommend a novel sky quality metric the ”Dark Sky Unit”, based on an easily usable and SI traceable unit. This unit is a natural choice for consistent, digital camera-based measurements. We also present our camera system calibration methodology for use with the introduced metrics.
Address ELTE BDPK, Szombathely, Department of Physics, Hungary; zkollath(at)gmail.com
Corporate Author Thesis
Publisher Elsever Place of Publication Elsevier 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 (down) 2998
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