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Author Brüning, A.; Kloas, W.; Preuer, T.; Hölker, F. url  doi
openurl 
  Title Influence of artificially induced light pollution on the hormone system of two common fish species, perch and roach, in a rural habitat Type Journal Article
  Year 2018 Publication Conservation Physiology Abbreviated Journal  
  Volume 6 Issue 1 Pages  
  Keywords (up) Animals  
  Abstract Almost all life on earth has adapted to natural cycles of light and dark by evolving circadian and circannual rhythms to synchronize behavioural and physiological processes with the environment. Artificial light at night (ALAN) is suspected to interfere with these rhythms. In this study we examined the influence of ALAN on nocturnal melatonin and sex steroid blood concentrations and mRNA expression of gonadotropins in the pituitary of European perch (Perca fluviatilis) and roach (Rutilus rutilus). In a rural experimental setting, fish were held in net cages in drainage channels experiencing either additional ALAN of ~15 lx at the water surface or natural light conditions at half-moon. No differences in melatonin concentrations between ALAN and natural conditions were detected. However, blood concentration of sex steroids (17β-estradiol; 11-ketotestosterone) as well as mRNA expression of gonadotropins (luteinizing hormone, follicle stimulating hormone) was reduced in both fish species. We conclude that ALAN can disturb biological rhythms in fish in urban waters. However, impacts on melatonin rhythm might have been blurred by individual differences, sampling methods and moonlight. The effect of ALAN on biomarkers of reproduction suggests a photo-labile period around the onset of gonadogenesis, including the experimental period (August). Light pollution therefore has a great potential to influence crucial life history traits with unpredictable outcome for fish population dynamics.  
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  ISSN 2051-1434 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1858  
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Author Eriksen, A.; Wabakken, P. url  doi
openurl 
  Title Activity patterns at the Arctic Circle: nocturnal eagle owls and interspecific interactions during continuous midsummer daylight Type Journal Article
  Year 2018 Publication Journal of Avian Biology Abbreviated Journal J Avian Biol  
  Volume 49 Issue 7 Pages e01781  
  Keywords (up) Animals  
  Abstract Circadian rhythms result from adaptations to biotic and abiotic environmental conditions that cycle through the day, such as light, temperature, or temporal overlap between interacting species. At high latitudes, close to or beyond the polar circles, uninterrupted midsummer daylight may pose a challenge to the circadian rhythms of otherwise nocturnal species, such as eagle owls Bubo bubo. By non‐invasive field methods, we studied eagle owl activity in light of their interactions with their main prey the water vole Arvicola amphibius, and their competitor the white‐tailed eagle Haliaeetus albicilla during continuous midsummer daylight on open, treeless islands in coastal Northern Norway. We evaluated circadian rhythms, temporal overlap, exposure, and spatial distribution. The owls maintained a nocturnal activity pattern, possibly because slightly dimmer light around midnight offered favourable hunting conditions. The eagles were active throughout the 24‐hour period as opposed to the strictly diurnal rhythm reported elsewhere, thus increasing temporal overlap and the potential for interference competition between the two avian predators. This may indicate an asymmetry, with the owls facing the highest cost of interference competition. The presence of eagles combined with constant daylight in this open landscape may make the owls vulnerable to interspecific aggression, and contrary to the available literature, eagle owls rarely exposed themselves visually during territorial calls, possibly to avoid detection by eagles. We found indications of spatial segregation between owls and eagles reflecting differences in main prey, possibly in combination with habitat‐mediated avoidance. Eagle owl vocal activity peaked in the evening before a nocturnal peak in visual observations, when owls were active hunting, consistent with the hypothesis of a dusk chorus in nocturnal bird species. The owls may have had to trade‐off between calling and foraging during the few hours around midnight when slightly dimmer light reduced the detection risk while also providing better hunting conditions.  
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  ISSN 0908-8857 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1881  
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Author Madahi, P.-G.; Ivan, O.; Adriana, B.; Diana, O.; Carolina, E. url  doi
openurl 
  Title Constant light during lactation programs circadian and metabolic systems Type Journal Article
  Year 2018 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 35 Issue 8 Pages 1153-1167  
  Keywords (up) Animals  
  Abstract Exposure to light at night is a disruptive condition for the adult circadian system, leading to arrhythmicity in nocturnal rodents. Circadian disruption is a risk factor for developing physiological and behavioral alterations, including weight gain and metabolic disease. During early stages of development, the circadian system undergoes a critical period of adjustment, and it is especially vulnerable to altered lighting conditions that may program its function, leading to long-term effects. We hypothesized that during lactation a disrupted light-dark cycle due to light at night may disrupt the circadian system and in the long term induce metabolic disorders. Here we explored in pups, short- and long-term effects of constant light (LL) during lactation. In the short term, LL caused a loss of rhythmicity and a reduction in the immunopositive cells of VIP, AVP, and PER1 in the suprachiasmatic nucleus (SCN). In the short term, the affection on the circadian clock in the pups resulted in body weight gain, loss of daily rhythms in general activity, plasma glucose and triglycerides (TG). Importantly, the DD conditions during development also induced altered daily rhythms in general activity and in the SCN. Exposure to LD conditions after lactation did not restore rhythmicity in the SCN, and the number of immunopositve cells to VIP, AVP, and PER1 remained reduced. In the long term, daily rhythmicity in general activity was restored; however, daily rhythms in glucose and TG remained disrupted, and daily mean levels of TG were significantly increased. Present results point out the programming role played by the LD cycle during early development in the function of the circadian system and on metabolism. This study points out the risk represented by exposure to an altered light-dark cycle during early stages of development. ABBREVIATIONS: AVP: arginine vasopressin peptide; CRY: cryptochrome; DD: constant darkness; DM: dorsomedial; LD: light-dark cycle; LL: constant light; NICUs: neonatal intensive care units; P: postnatal days; PER: period; S.E.M.: standard error of the mean; SCN: suprachiasmatic nucleus; TG: triglycerides; VIP: vasointestinal peptide; VL: ventrolateral; ZT: zeitgeber time.  
  Address a Facultad de Medicina , Universidad Nacional Autonoma de Mexico, UNAM , Mexico City , Mexico  
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  Series Volume Series Issue Edition  
  ISSN 0742-0528 ISBN Medium  
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  Notes PMID:29688088 Approved no  
  Call Number GFZ @ kyba @ Serial 1884  
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Author McLay, L.K.; Nagarajan-Radha, V.; Green, M.P.; Jones, T.M. url  doi
openurl 
  Title Dim artificial light at night affects mating, reproductive output, and reactive oxygen species in Drosophila melanogaster Type Journal Article
  Year 2018 Publication Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology Abbreviated Journal J Exp Zool A Ecol Integr Physiol  
  Volume 329 Issue 8-9 Pages 419-428  
  Keywords (up) Animals  
  Abstract Humans are lighting the night-time environment with ever increasing extent and intensity, resulting in a variety of negative ecological effects in individuals and populations. Effects of light at night on reproductive fitness traits are demonstrated across taxa however, the mechanisms underlying these effects are largely untested. One possible mechanism is that light at night may result in perturbed reactive oxygen species (ROS) and oxidative stress levels. Here, we reared Drosophila melanogaster under either dim (10 lx) light or no light (0 lx) at night for three generations and then compared mating and lifetime oviposition patterns. In a second experiment, we explored whether exposure to light at night treatments resulted in variation in ROS levels in the heads and ovaries of six, 23- and 36-day-old females. We demonstrate that dim light at night affects mating and reproductive output: 10 lx flies courted for longer prior to mating, and female oviposition patterns differed to 0 lx females. ROS levels were lower in the ovaries but not heads, of 10 lx compared with 0 lx females. We suggest that reduced ROS levels may reflect changes in ovarian physiology and cell signaling, which may be related to the differences observed in oviposition patterns. Taken together, our results indicate negative consequences for invertebrates under more stressful, urban, lit conditions and further investigation into the mechanisms driving these changes is warranted to manage invertebrate communities in a brighter future.  
  Address School of BioSciences, Faculty of Science, The University of Melbourne, Melbourne, Victoria, Australia  
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  Series Volume Series Issue Edition  
  ISSN 2471-5638 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29733537 Approved no  
  Call Number GFZ @ kyba @ Serial 1889  
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Author Borck, P.C.; Batista, T.M.; Vettorazzi, J.F.; Soares, G.M.; Lubaczeuski, C.; Guan, D.; Boschero, A.C.; Vieira, E.; Lazar, M.A.; Carneiro, E.M. url  doi
openurl 
  Title Nighttime light exposure enhances Rev-erbalpha-targeting microRNAs and contributes to hepatic steatosis Type Journal Article
  Year 2018 Publication Metabolism: Clinical and Experimental Abbreviated Journal Metabolism  
  Volume 85 Issue Pages 250-258  
  Keywords (up) Animals  
  Abstract OBJECTIVE: The exposure to artificial light at night (ALAN) disrupts the biological rhythms and has been associated with the development of metabolic syndrome. MicroRNAs (miRNAs) display a critical role in fine-tuning the circadian system and energy metabolism. In this study, we aimed to assess whether altered miRNAs expression in the liver underlies metabolic disorders caused by disrupted biological rhythms. RESULTS: We found that C3H/HePas mice exposed to ALAN developed obesity, and hepatic steatosis, which was paralleled by decreased expression of Rev-erbalpha and up-regulation of its lipogenic targets ACL and FAS in liver. Furthermore, the expression of Rev-erbalpha-targeting miRNAs, miR-140-5p, 185-5p, 326-5p and 328-5p were increased in this group. Consistently, overexpression of these miRNAs in primary hepatocytes reduced Rev-erbalpha expression at the mRNA and protein levels. Importantly, overexpression of Rev-erbalpha-targeting miRNAs increased mRNA levels of Acly and Fasn. CONCLUSION: Thus, altered miRNA profile is an important mechanism underlying the disruption of the peripheral clock caused by exposure to ALAN, which could lead to hepatic steatosis.  
  Address Obesity and Comorbidities Research Center, Institute of Biology, University of Campinas/UNICAMP, Campinas, SP, Brazil; Department of Structural and Functional Biology, Institute of Biology, University of Campinas/UNICAMP, Campinas, SP, Brazil  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0026-0495 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29751019 Approved no  
  Call Number GFZ @ kyba @ Serial 1891  
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