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Author Hansen, M.J.; Cocherell, D.E.; Cooke, S.J.; Patrick, P.H.; Sills, M.; Fangue, N.A. url  doi
openurl 
  Title Behavioural guidance of Chinook salmon smolts: the variable effects of LED spectral wavelength and strobing frequency Type Journal Article
  Year 2018 Publication Conservation Physiology Abbreviated Journal  
  Volume 6 Issue 1 Pages  
  Keywords Animals  
  Abstract Exploiting species-specific behavioural responses of fish to light is an increasingly promising technique to reduce the entrainment or impingement of fish that results from the diversion of water for human activities, such as hydropower or irrigation. Whilst there is some evidence that white light can be an effective deterrent for Chinook salmon smolts, the results have been mixed. There is a need to test the response of fish to different spectra and strobing frequencies to improve deterrent performance. We tested the movement and spatial response of groups of four fish to combinations of light-emitting diode (LED) spectra (red, green, blue and white light) during the day and night, and strobing frequencies (constant and 2Hz) during the day, using innovative LED technology intended as a behavioural guidance device for use in the field. Whilst strobing did not alter fish behaviour when compared to constant light, the red light had a repulsive effect during the day, with fish under this treatment spending significantly less time in the half of the arena closest to the behavioural guidance device compared to both the control and blue light. Importantly, this effect disappeared at night, where there were no differences in movement and space use found between spectra. There was some evidence of a potential attractive response of fish to the blue and green light during the day. Under these light treatments, fish spent the highest amount of time closest to the behavioural guidance device. Further tests manipulating the light intensity in the different spectra are needed to verify the mechanistic determinants of the observed behaviours. Results are discussed in reference to the known spectral sensitivities of the cone and rod photopigments in these fish, and further experiments are suggested to better relate the work to mitigating the effects on fish of infrastructure used for hydropower and irrigation.  
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  Series Volume Series Issue Edition  
  ISSN 2051-1434 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1947  
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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 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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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2051-1434 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1858  
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Author Girard, M.B.; Kasumovic, M.M.; Elias, D.O. url  doi
openurl 
  Title The role of red coloration and song in peacock spider courtship: insights into complex signaling systems Type Journal Article
  Year 2018 Publication Behavioral Ecology Abbreviated Journal  
  Volume in press Issue Pages  
  Keywords Animals  
  Abstract Research on animal signaling enhances our understanding of links between sensory processing, decision making, behavior, and evolution. Studies of sexually-selected signals may be particularly informative as mate choice provides access to decision patterns in the way that courtship leads to an easily observable behavioral output in choosers, i.e., mating. Male peacock spiders have some of the most elaborate and varied courtship displays known among animals. Particularly striking to human observers is the diversity of red, orange, and yellow ornaments that males exhibit across the genus. The primary objective of our research was to investigate how these visual ornaments interact with vibratory songs to affect female mating behavior of one species, Maratus volans. Accordingly, we conducted mating trials under a series of experimentally manipulated vibratory and lighting conditions. Contrary to expectation, chromatic characteristics of longer wavelength ornaments are not driving female mate choice decisions, despite their extensive presence on male fans. Instead, our results suggest that contrast is important to females. Additionally, we found that vibratory signals were not necessary and did not increase mating rates. Our study demonstrates the intricacies inherent in complex signaling systems.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1045-2249 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2027  
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Author Obayashi, K.; Saeki, K.; Kurumatani, N. url  doi
openurl 
  Title Obayashi et al. Respond to “Light at Night Predicts Depression—What Next?” Type Journal Article
  Year 2018 Publication American Journal of Epidemiology Abbreviated Journal  
  Volume 187 Issue 3 Pages 439-440  
  Keywords Commentary; Human Health  
  Abstract Our research includes some strengths and limitations. The most important strength is objective measurement of light at night (LAN) intensity using a bedside light meter. Most previous studies evaluating the association between LAN and health outcomes have assessed indoor LAN levels using a self-reported questionnaire or outdoor LAN levels using satellite data; however, self-reported indoor LAN levels has not yet been validated with objective measurement and outdoor LAN levels are surrogates for an individual LAN exposure. The second strength of our study includes its longitudinal design using multivariable methods to adjust for confounders, which indicated LAN exposure may be a cause of the incidence of depressive symptoms. Indeed, the depressive score evaluated by questionnaires may be above or below the cut-off value over the short term; therefore, a long-term study considering such unstable outcomes should be conducted. In the current study, LAN exposure was measured for only two nights; thus, an amplitude of LAN intensity has been focused. However, multiple measurements over time in the future study would allow an analysis of fluctuations in LAN exposure, which might be important for circadian physiology.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0002-9262 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1717  
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Author Hasler, B.P. url  doi
openurl 
  Title Commentary on Bedroom Light Exposure at Night and the Incidence of Depressive Symptoms: A Longitudinal Study of the HEIJOKYO Cohort (Obayashi et al) Type Journal Article
  Year 2018 Publication American Journal of Epidemiology Abbreviated Journal  
  Volume 187 Issue 3 Pages 435-438  
  Keywords Commentary; Human Health  
  Abstract In modern society, we are increasingly disconnected from natural light/dark cycles and beset by round-the-clock exposure to artificial light. Light has powerful effects on physical and mental health, in part via the circadian system, and thus the timing of light exposure dictates whether it is helpful or harmful. In their compelling paper, Obayashi and colleagues offer evidence that light at night can prospectively predict an elevated incidence of depressive symptoms in older adults. Strengths of the study include the longitudinal design and direct, objective assessment of light levels, as well as accounting for multiple plausible confounders during analyses. Follow-up studies should address the study's limitations, including reliance on a global self-report of sleep quality and a two-night assessment of light exposure that may not reliably represent typical light exposure. In addition, experimental studies including physiological circadian measures will be necessary to determine if the light effects on depression are mediated through the circadian system or are so-called “direct” effects of light. In any case, these exciting findings could inform novel new approaches to preventing depressive disorders in older adults.  
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  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 0002-9262 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1716  
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