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Author Fonken, L.K.; Bedrosian, T.A.; Zhang, N.; Weil, Z.M.; DeVries, A.C.; Nelson, R.J.
Title Dim light at night impairs recovery from global cerebral ischemia Type Journal Article
Year 2019 Publication Experimental Neurology Abbreviated Journal Exp Neurol
Volume (up) in press Issue Pages
Keywords Animals
Abstract Nighttime lighting is one of the great conveniences of modernization; however, there is mounting evidence that inopportune light exposure can disrupt physiological and behavioral functions. Hospital patients may be particularly vulnerable to the consequences of light at night due to their compromised physiological state. Cardiac arrest/cardiopulmonary resuscitation (CA) was used to test the hypothesis in mice that exposure to dim light at night impairs central nervous system (CNS) recovery from a major pathological insult. Mice exposed to dim light at night (5lx) had higher mortality in the week following cardiac arrest compared to mice housed in dark nights (0lx). Neuronal damage was significantly greater in surviving mice exposed to dim light at night after CA versus those housed in dark nights. Dim light at night may have elevated neuronal damage by amplifying pro-inflammatory pathways in the CNS; Iba1 immunoreactivity (an indication of microglia activation) and pro-inflammatory cytokine expression were elevated in mice exposed to dim light at night post-CA. Furthermore, selective inhibition of IL-1beta or TNFalpha ameliorated damage in mice exposed to dim light at night. The effects of light at night on CA outcomes were also prevented by using a wavelength of nighttime light that has minimal impact on the endogenous circadian clock, suggesting that replacing broad-spectrum nighttime light with specific circadian-inert wavelengths could be protective. Together, these data indicate that exposure to dim light at night after global cerebral ischemia increases neuroinflammation, in turn exacerbating neurological damage and potential for mortality.
Address Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, 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 0014-4886 ISBN Medium
Area Expedition Conference
Notes PMID:30822422 Approved no
Call Number GFZ @ kyba @ Serial 2235
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Author Nagare, R.; Rea, M.S.; Plitnick, B.; Figueiro, M.G.
Title Nocturnal Melatonin Suppression by Adolescents and Adults for Different Levels, Spectra, and Durations of Light Exposure Type Journal Article
Year 2019 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume (up) in press Issue Pages
Keywords Human Health; Physiology
Abstract The human circadian system is primarily regulated by the 24-h LD cycle incident on the retina, and nocturnal melatonin suppression is a primary outcome measure for characterizing the biological clock's response to those light exposures. A limited amount of data related to the combined effects of light level, spectrum, and exposure duration on nocturnal melatonin suppression has impeded the development of circadian-effective lighting recommendations and light-treatment methods. The study's primary goal was to measure nocturnal melatonin suppression for a wide range of light levels (40 to 1000 lux), 2 white light spectra (2700 K and 6500 K), and an extended range of nighttime light exposure durations (0.5 to 3.0 h). The study's second purpose was to examine whether differences existed between adolescents' and adults' circadian sensitivity to these lighting characteristics. The third purpose was to provide an estimate of the absolute threshold for the impact of light on acute melatonin suppression. Eighteen adolescents (age range, 13 to 18 years) and 23 adults (age range, 24 to 55 years) participated in the study. Results showed significant main effects of light level, spectrum, and exposure duration on melatonin suppression. Moreover, the data also showed that the relative suppressing effect of light on melatonin diminishes with increasing exposure duration for both age groups and both spectra. The present results do not corroborate our hypothesis that adolescents exhibit greater circadian sensitivity to short-wavelength radiation compared with adults. As for threshold, it takes longer to observe significant melatonin suppression at lower CS levels than at higher CS levels. Dose-response curves (amount and duration) for both white-light spectra and both age groups can guide lighting recommendations when considering circadian-effective light in applications such as offices, schools, residences, and healthcare facilities.
Address Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, 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 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:30803301 Approved no
Call Number GFZ @ kyba @ Serial 2237
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Author Nagare, R.; Rea, M.S.; Plitnick, B.; Figueiro, M.G.
Title Effect of White Light Devoid of “Cyan” Spectrum Radiation on Nighttime Melatonin Suppression Over a 1-h Exposure Duration Type Journal Article
Year 2019 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume (up) in press Issue Pages
Keywords Human Health
Abstract The intrinsically photosensitive retinal ganglion cells are the main conduit of the light signal emanating from the retina to the biological clock located in the suprachiasmatic nuclei of the hypothalamus. Lighting manufacturers are developing white light sources that are devoid of wavelengths around 480 nm (“cyan gap”) to reduce their impact on the circadian system. The present study was designed to investigate whether exposure to a “cyan-gap,” 3000 K white light source, spectrally tuned to reduce radiant power between 475 and 495 nm (reducing stimulation of the melanopsin-containing photoreceptor), would suppress melatonin less than a conventional 3000 K light source. The study's 2 phases employed a within-subjects experimental design involving the same 16 adult participants. In Phase 1, participants were exposed for 1 h to 3 experimental conditions over the course of 3 consecutive weeks: 1) dim light control (<5 lux at the eyes); 2) 800 lux at the eyes of a 3000 K light source; and 3) 800 lux at the eyes of a 3000 K, “cyan-gap” modified (3000 K mod) light source. The same protocol was repeated in Phase 2, but light levels were reduced to 400 lux at the eyes. As hypothesized, there were significant main effects of light level ( F1,12 = 9.1, p < 0.05, etap(2) = 0.43) and exposure duration ( F1,12 = 47.7, p < 0.05, etap(2) = 0.80) but there was no significant main effect of spectrum ( F1,12 = 0.16, p > 0.05, etap(2) = 0.01). There were no significant interactions with spectrum. Contrary to our model predictions, our results showed that short-term exposures (</= 1 h) to “cyan-gap” light sources suppressed melatonin similarly to conventional light sources of the same CCT and photopic illuminance at the eyes.
Address Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, 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 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:30821188 Approved no
Call Number GFZ @ kyba @ Serial 2240
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Author Viera-Perez, M.; Hernandez-Calvento, L.; Hesp, P.A.; Santana-Del Pino, A.
Title Effects of artificial light on flowering of foredune vegetation Type Journal Article
Year 2019 Publication Ecology Abbreviated Journal Ecology
Volume (up) in press Issue Pages
Keywords Plants
Abstract The impact of ecological light pollution involves alteration of periods of natural light, a fact that has proven effects on ecosystems. Few studies have focused on the impact of this pollution on wild plant species, and none on coastal dune plants. Many coastal dunes and their plants are adjacent to tourist areas, and these might be affected by light pollution. Such is the case of the Natural Reserve Dunas de Maspalomas (Gran Canaria), where some individuals of the plant species Traganum moquinii, located in the El Ingles beach foredune zone, are affected by light pollution. This study examines the effect of light pollution on the flowering process, and by extension the reproductive cycle of these plants. Plants located closer to high artificial illumination sources receive ~2120 hours per year of intense light more than plants located furthest from those artificial lighting sources. Parts of the plants of Traganum moquinii exposed directly to the artificial light show a significant decrease in the production of flowers, compared to the parts in plants in shade, and to the plants more distant from artificial lights. In consequence, plants exposed more directly to artificial light have a lower potential for seed reproduction. The spectrum of artificial light also affects the plants, and light between 600 and 700 nm primarily affects the reproductive cycle of the Traganum moquinii species. The implications for the ecological and geomorphological functioning of the dune system are discussed, because this species plays a decisive role in the formation of foredune zones and nebkhas in arid dune systems. This article is protected by copyright. All rights reserved.
Address Departamento de Matematicas, Universidad de Las Palmas de Gran Canaria, 35017, Las Palmas de Gran Canaria, Spain
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 0012-9658 ISBN Medium
Area Expedition Conference
Notes PMID:30825328 Approved no
Call Number GFZ @ kyba @ Serial 2244
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Author Hoglund, J.; Mitkus, M.; Olsson, P.; Lind, O.; Drews, A.; Bloch, N.I.; Kelber, A.; Strandh, M.
Title Owls lack UV-sensitive cone opsin and red oil droplets, but see UV light at night: retinal transcriptomes and ocular media transmittance Type Journal Article
Year 2019 Publication Vision Research Abbreviated Journal Vision Res
Volume (up) in press Issue Pages
Keywords Animals; Vision
Abstract Most diurnal birds have cone-dominated retinae and tetrachromatic colour vision based on ultra-violet/violet-sensitive UV/V cones expressing short wavelength-sensitive opsin 1 (SWS1), S cones expressing short wavelength-sensitive opsin 2 (SWS2), M cones expressing medium wavelength-sensitive opsin (RH2) and L cones expressing long wavelength-sensitive opsin (LWS). Double cones (D) express LWS but do not contribute to colour vision. Each cone is equipped with an oil droplet, transparent in UV/V cones, but pigmented by carotenoids: galloxanthin in S, zeaxanthin in M, astaxanthin in L and a mixture in D cones. Owls (Strigiformes) are crepuscular or nocturnal birds with rod-dominated retinae and optical adaptations for high sensitivity. For eight species, the absence of functional SWS1 opsin has recently been documented, functional RH2 opsin was absent in three of these. Here we confirm the absence of SWS1 transcripts for the Long-eared owl (Asio otus) and demonstrate its absence for the Short-eared owl (Asio flammeus), Tawny owl (Strix aluco) and Boreal owl (Aegolius funereus). All four species had transcripts of RH2, albeit with low expression. All four species express all enzymes needed to produce galloxanthin, but lack CYP2J19 expression required to produce astaxanthin from dietary precursors. We also present ocular media transmittance of the Eurasian eagle owl (Bubo bubo) and Short-eared owl and predict spectral sensitivities of all photoreceptors of the Tawny owl. We conclude that owls, despite lacking UV/V cones, can detect UV light. This increases the sensitivity of their rod vision allowing them, for instance, to see UV-reflecting feathers as brighter signals at night.
Address Department of Biology, Lund University, Lund, Sweden
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 0042-6989 ISBN Medium
Area Expedition Conference
Notes PMID:30825468 Approved no
Call Number GFZ @ kyba @ Serial 2245
Permanent link to this record