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Author (up) Bapary, M.A.J.; Takano, J.-I.; Soma, S.; Sankai, T.
Title Effect of blue LED light and antioxidants potential in a somatic cell Type Journal Article
Year 2019 Publication Cell Biology International Abbreviated Journal Cell Biol Int
Volume in press Issue Pages
Keywords Cells; Biology
Abstract Light is an indispensable part of routine laboratory works in which conventional light is generally used. Light-emitting diodes (LEDs) have come to replace the conventional light thus could be a potent target in biomedical studies. Since blue light is a major component of visible light wavelength, in this study, using a somatic cell from African green monkey kidney, we assessed the possible consequences of blue spectra of LED light in future animal experiments and proposed a potent mitigation against light induced damages. COS-7 cells were exposed to blue LED light (450 nm) and the growth and DNA damage were assessed at different exposure times. A higher suppression in cell growth and viability was observed under a longer period of blue LED light exposure. The number of apoptotic cells increased as light exposure time was prolonged. Reactive oxygen species generation was also elevated in accordance to the extension of light exposure times. A comparison to dark-maintained cells revealed that the upregulation of ROS by blue LED light plays a significant role in causing cellular dysfunction in DNA in a time-dependent manner. In turn, antioxidant treatment has shown to improve the cell growth and viability under blue LED light conditions. This indicates that antioxidants are potential against blue LED light-induced somatic cell damage. It is expected that this study will contribute to the understanding of the basic mechanism of somatic cell death under visible light and to maximize the beneficial use of LED light in future animal experiments. This article is protected by copyright. All rights reserved.
Address Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Japan
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 1065-6995 ISBN Medium
Area Expedition Conference
Notes PMID:30958611 Approved no
Call Number GFZ @ kyba @ Serial 2328
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Author (up) Bará, S.
Title Black-body luminance and magnitudes per square arcsecond in the Johnson-Cousins BVR photometric bands Type Journal Article
Year 2019 Publication Photonics Letters of Poland Abbreviated Journal Photon. Lett. Pl.
Volume 11 Issue 3 Pages 63
Keywords Skyglow; night sky brightness; luminance; photometric
Abstract A relevant amount of light pollution studies deal with the unwanted visual effects of artificial light at night, including the anthropogenic luminance of the sky that hinders the observation of the celestial bodies which are a main target of ground-based astrophysical research, and a key asset of the intangible heritage of humankind. Most quantitative measurements and numerical models, however, evaluate the anthropogenic sky radiance in any of the standard Johnson-Cousins UBVRI photometric bands, generally in the V one. Since the Johnson-Cousins V band is not identical with the visual CIE V-lambda used to assess luminance, the conversion between these two photometric systems turns out to be spectrum-dependent. Given its interest for practical applications, in this Letter we provide the framework to perform this conversion and the transformation constants for black-body spectra of different absolute temperatures.
Address Dept. Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia
Corporate Author Thesis
Publisher Photonics Society of Poland Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2080-2242 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2685
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Author (up) Bará, S.
Title Variations on a classical theme: On the formal relationship between magnitudes per square arcsecond and luminance Type Journal Article
Year 2017 Publication International Journal of Sustainable Lighting Abbreviated Journal Intl J of Sustainable Lighting
Volume 19 Issue 2 Pages 77
Keywords Instrumentation; skyglow; luminance; magnitude; sky brigthness; photometry
Abstract The formal link between magnitudes per square arcsecond and luminance is discussed in this paper. Directly related to the human visual system, luminance is defined in terms of the spectral radiance of the source, weighted by the CIE V(l) luminous efficiency function, and scaled by the 683 lm/W luminous efficacy constant. In consequence, any exact and spectrum-independent relationship between luminance and magnitudes per square arcsecond requires that the last ones be measured precisely in the CIE V(l) band. The luminance value corresponding to mVC=0 (zero-point of the CIE V(l) magnitude scale) depends on the reference source chosen for the definition of the magnitude system. Using absolute AB magnitudes, the zero point luminance of the CIE V(l) photometric band is 10.96 x 104 cd·m-2.
Address Departamento de Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2586-1247 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2162
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Author (up) 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 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 (up) Bará, S.
Title Anthropogenic disruption of the night sky darkness in urban and rural areas Type Journal Article
Year 2016 Publication Royal Society Open Science Abbreviated Journal R. Soc. open sci.
Volume 3 Issue 10 Pages 160541
Keywords Skyglow
Abstract The growing emissions of artificial light to the atmosphere are producing, among other effects, a significant increase of the night sky brightness (NSB) above its expected natural values. A permanent sensor network has been deployed in Galicia (northwest of Iberian peninsula) to monitor the anthropogenic disruption of the night sky darkness in a countrywide area. The network is composed of 14 detectors integrated in automated weather stations of MeteoGalicia, the Galician public meteorological agency. Zenithal NSB readings are taken every minute and the results are openly available in real time for researchers, interested stakeholders and the public at large through a dedicated website. The measurements allow one to assess the extent of the loss of the natural night in urban, periurban, transition and dark rural sites, as well as its daily and monthly time courses. Two metrics are introduced here to characterize the disruption of the night darkness across the year: the significant magnitude (m1/3) and the moonlight modulation factor (γ). The significant magnitude shows that in clear and moonless nights the zenithal night sky in the analysed urban settings is typically 14–23 times brighter than expected from a nominal natural dark sky. This factor lies in the range 7–8 in periurban sites, 1.6–2.5 in transition regions and 0.8–1.6 in rural and mountain dark sky places. The presence of clouds in urban areas strongly enhances the amount of scattered light, easily reaching amplification factors in excess of 25, in comparison with the light scattered in the same places under clear sky conditions. The periodic NSB modulation due to the Moon, still clearly visible in transition and rural places, is barely notable at periurban locations and is practically lost at urban sites.
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 2054-5703 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1544
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