|   | 
Details
   web
Records
Author Bará, S.; Nievas, M.; Sanchez de Miguel, A.; Zamorano, J.
Title Zernike analysis of all-sky night brightness maps Type Journal Article
Year 2014 Publication Applied Optics Abbreviated Journal Appl Opt
Volume 53 Issue 12 Pages (down) 2677-2686
Keywords modeling; light at night; light pollution; all-sky; Zernike polynomials; image decomposition; sky brightness
Abstract All-sky night brightness maps (calibrated images of the night sky with hemispherical field-of-view (FOV) taken at standard photometric bands) provide useful data to assess the light pollution levels at any ground site. We show that these maps can be efficiently described and analyzed using Zernike circle polynomials. The relevant image information can be compressed into a low-dimensional coefficients vector, giving an analytical expression for the sky brightness and alleviating the effects of noise. Moreover, the Zernike expansions allow us to quantify in a straightforward way the average and zenithal sky brightness and its variation across the FOV, providing a convenient framework to study the time course of these magnitudes. We apply this framework to analyze the results of a one-year campaign of night sky brightness measurements made at the UCM observatory in Madrid.
Address Área de Óptica, Dept. de Física Aplicada, Fac. de Física, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain
Corporate Author Thesis
Publisher Optical Society of America Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6935 ISBN Medium
Area Expedition Conference
Notes PMID:24787595 Approved no
Call Number IDA @ john @ Serial 318
Permanent link to this record
 

 
Author Baekelandt, S.; Milla, S.; Cornet, V.; Flamion, E.; Ledore, Y.; Redivo, B.; Antipine, S.; Mandiki, S.N.M.; Houndji, A.; El Kertaoui, N.; Kestemont, P.
Title Seasonal simulated photoperiods influence melatonin release and immune markers of pike perch Sander lucioperca Type Journal Article
Year 2020 Publication Scientific Reports Abbreviated Journal Sci Rep
Volume 10 Issue 1 Pages (down) 2650
Keywords Animals
Abstract Melatonin is considered as the time-keeping hormone acting on important physiological functions of teleosts. While the influence of melatonin on reproduction and development is well described, its potential role on immune functions has little been considered. In order to better define an immune modulation by the melatonin hormone, we hypothesized that natural variations of photoperiod and subsequent changes in melatonin release profile may act on immune status of pikeperch. Therefore, we investigated during 70 days the effects of two photoperiod regimes simulating the fall and spring in western Europe, on pikeperch physiological and immune responses. Samples were collected at 04:00 and 15:00 at days 1, 37 and 70. Growth, plasma melatonin levels, innate immune markers and expression of immune-relevant genes in head kidney tissue were assessed. While growth and stress level were not affected by the seasonal simulated photoperiods, nocturnal levels of plasma melatonin were photoperiod-dependent. Innate immune markers, including lysozyme, complement, peroxidase and phagocytic activities, were stimulated by the fall-simulated photoperiod and a significant correlation was made with plasma melatonin. In addition to bring the first evidence of changes in fish immunocompetence related to photoperiod, our results provide an additional indication supporting the immunomodulatory action of melatonin in teleosts.
Address Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur, Rue de Bruxelles 61, Namur, B-5000, Belgium
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 2045-2322 ISBN Medium
Area Expedition Conference
Notes PMID:32060347; PMCID:PMC7021833 Approved no
Call Number GFZ @ kyba @ Serial 2942
Permanent link to this record
 

 
Author Davies, T.W.; Bennie, J.; Cruse, D.; Blumgart, D.; Inger, R.; Gaston, K.J.
Title Multiple night-time light-emitting diode lighting strategies impact grassland invertebrate assemblages Type Journal Article
Year 2017 Publication Global Change Biology Abbreviated Journal Glob Chang Biol
Volume 23 Issue 7 Pages (down) 2641-2648
Keywords Ecology; grasslands; LED
Abstract White light-emitting diodes (LEDs) are rapidly replacing conventional outdoor lighting technologies around the world. Despite rising concerns over their impact on the environment and human health, the flexibility of LEDs has been advocated as a means of mitigating the ecological impacts of globally widespread outdoor night-time lighting through spectral manipulation, dimming and switching lights off during periods of low demand. We conducted a three-year field experiment in which each of these lighting strategies was simulated in a previously artificial light naive grassland ecosystem. White LEDs both increased the total abundance and changed the assemblage composition of adult spiders and beetles. Dimming LEDs by 50% or manipulating their spectra to reduce ecologically damaging wavelengths partially reduced the number of commoner species affected from seven to four. A combination of dimming by 50% and switching lights off between midnight and 04:00 am showed the most promise for reducing the ecological costs of LEDs, but the abundances of two otherwise common species were still affected. The environmental consequences of using alternative lighting technologies are increasingly well established. These results suggest that while management strategies using LEDs can be an effective means of reducing the number of taxa affected, averting the ecological impacts of night-time lighting may ultimately require avoiding its use altogether.
Address Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
Corporate Author Thesis
Publisher Wiley Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1354-1013 ISBN Medium
Area Expedition Conference
Notes PMID:28139040 Approved no
Call Number LoNNe @ kyba @ Serial 1634
Permanent link to this record
 

 
Author Puschnig, J.; Wallner, S.; Posch, T.
Title Circalunar variations of the night sky brightness – an FFT perspective on the impact of light pollution Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 492 Issue 2 Pages (down) 2622-2637
Keywords Skyglow; Moonlight
Abstract Circa-monthly activity conducted by moonlight is observed in many species on Earth. Given the vast amount of artificial light at night (ALAN) that pollutes large areas around the globe, the synchronization to the circalunar cycle is often strongly perturbed. Using 2-yr data from a network of 23 photometers (Sky Quality Meters; SQM) in Austria (latitude ∼48°), we quantify how light pollution impacts the recognition of the circalunar periodicity. We do so via frequency analysis of nightly mean sky brightnesses using Fast Fourier Transforms. A very tight linear relation between the mean zenithal night sky brightness (NSB) given in magSQMarcsec−2 and the amplitude of the circalunar signal is found, indicating that for sites with a mean zenithal NSB brighter than 16.5 magSQMarcsec−2 the lunar rhythm practically vanishes. This finding implies that the circalunar rhythm is still detectable (within the broad bandpass of the SQM) at most places around the globe, but its amplitude against the light polluted sky is strongly reduced. We find that the circalunar contrast in zenith is reduced compared to ALAN-free sites by factors of 19 in the state capital of Linz (∼200 000 inhabitants) and 13 in small towns, e.g. Freistadt and Mattighofen, with less than 10 000 inhabitants. Only two of our sites, both situated in national parks (Bodinggraben and Zöblboden), show natural circalunar amplitudes. At our urban sites, we further detect a strong seasonal signal that is linked to the amplification of anthropogenic skyglow during the winter months due to climatological conditions.
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 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2838
Permanent link to this record
 

 
Author Singhal, R. K., Kumar, V., Kumar, M., & Bose, B.
Title Responses of different light intensities and continue light during dark period on rice (Oryza sativa L.) seed germination and seedling development Type Journal Article
Year 2019 Publication Journal of Pharmacognosy and Phytochemistry Abbreviated Journal
Volume 8 Issue 4 Pages (down) 2602-2609
Keywords Plants
Abstract Temperature, humidity and moisture content are the important abiotic component regulating seedling establishment in plants including rice. Light factor intensity and duration are also important environmental factors regulating rice growth and development. In the growth and development of rice crop germination followed by seedling establishment is the foremost and very important growth stages. Light component such as intensity, direction and duration are the regulating factor for several physiological, biochemical and molecular processes in plants. To consider these facts, in the present piece of work rice seed of HUR-105 grown under different light regimes, from T1 (2000 lux for 12 h during day time + 12 h dark period) (lower light intensity), T2 (4000 lux for 12 h during day time+ 12 h dark period), T3 (6000 lux for 12 h during day time + 12 h dark period) (moderate), T4 (9000 lux for 12 h during day time + 12 h dark period) (optimum) and to T5 (9000 lux for 12h during day time + 200 lux for 12 h during night time). Germination, seedling growth and biochemical parameters were observed at different time intervals. It was observed that germination %, germination index (GI), germination rate index (GRI), coefficient of velocity of germination (CVG), mean germination rate (MGR), seedling vigour (SV), α-amylase activity and soluble sugar content significantly reduced in both the treatments T1 and T5. Further, the mean time germination and insoluble sugar content were increased in T1 and T5 treatment. The present experiment concluded that both lower light intensity (T1) and addition of low light during dark period (considered as night light pollution) causes stress condition and reduce germination and seedling establishment potential of rice crop.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ intern @ Serial 2738
Permanent link to this record