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Author Maroni, M.J.; Capri, K.M.; Cushman, A.V.; Monteiro De Pina, I.K.; Chasse, M.H.; Seggio, J.A. url  doi
openurl 
  Title Constant light alters serum hormone levels related to thyroid function in male CD-1 mice Type Journal Article
  Year 2018 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 35 Issue 10 Pages 1456-1463  
  Keywords (up) Animals  
  Abstract Disruptions to the circadian rhythm can lead to altered metabolism. Modification of thyroid function may be a reason why circadian misalignment may contribute to future metabolic disorders. We investigated whether circadian disruption through constant light (LL) can lead to variations in hormone levels associated with thyroid function. Mice were exposed to LL or a 12:12 Light:Dark (LD) cycle for 6 weeks; then glucose tolerance and thyroid hormone levels were measured at ZT 6 and ZT 18. There was day/night variation in glucose tolerance, but LL had no effect. LL reduced TSH, increased fT4, and abolished day/night variation in fT3 and leptin. These findings illustrate that LL alters thyroid-related hormones, providing evidence of a link between circadian disruption and thyroid function.  
  Address a Department of Biological Sciences , Bridgewater State University , Bridgewater , MA , 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 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29953263 Approved no  
  Call Number GFZ @ kyba @ Serial 1958  
Permanent link to this record
 

 
Author Dominoni, D.M.; de Jong, M.; Bellingham, M.; O'Shaughnessy, P.; van Oers, K.; Robinson, J.; Smith, B.; Visser, M.E.; Helm, B. url  doi
openurl 
  Title Dose-response effects of light at night on the reproductive physiology of great tits (Parus major): Integrating morphological analyses with candidate gene expression 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 in press Issue Pages in press  
  Keywords (up) Animals  
  Abstract Artificial light at night (ALAN) is increasingly recognized as a potential threat to wildlife and ecosystem health. Among the ecological effects of ALAN, changes in reproductive timing are frequently reported, but the mechanisms underlying this relationship are still poorly understood. Here, we experimentally investigated these mechanisms by assessing dose-dependent photoperiodic responses to ALAN in the great tit (Parus major). We individually exposed photosensitive male birds to one of three nocturnal light levels (0.5, 1.5, and 5 lux), or to a dark control. Subsequent histological and molecular analyses on their testes indicated a dose-dependent reproductive response to ALAN. Specifically, different stages of gonadal growth were activated after exposure to different levels of light at night. mRNA transcript levels of genes linked to the development of germ cells (stra8 and spo11) were increased under 0.5 lux compared to the dark control. The 0.5 and 1.5 lux groups showed slight increases in testis size and transcript levels associated with steroid synthesis (lhr and hsd3b1) and spermatogenesis (fshr, wt1, sox9, and cldn11), although spermatogenesis was not detected in histological analysis. In contrast, all birds under 5 lux had 10 to 30 times larger testes than birds in all other groups, with a parallel strong increase in mRNA transcript levels and clear signs of spermatogenesis. Across treatments, the volume of the testes was generally a good predictor of testicular transcript levels. Overall, our findings indicate that even small changes in nocturnal light intensity can increase, or decrease, effects on the reproductive physiology of wild organisms.  
  Address GELIFES, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands  
  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 2471-5638 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30058288 Approved no  
  Call Number GFZ @ kyba @ Serial 1964  
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Author Wilson, P.; Thums, M.; Pattiaratchi, C.; Meekan, M.; Pendoley, K.; Fisher, R.; Whiting, S. url  doi
openurl 
  Title Artificial light disrupts the nearshore dispersal of neonate flatback turtles Natator depressus Type Journal Article
  Year 2018 Publication Marine Ecology Progress Series Abbreviated Journal Mar. Ecol. Prog. Ser.  
  Volume 600 Issue Pages 179-192  
  Keywords (up) Animals  
  Abstract After emerging from nests, neonate sea turtles entering the water are thought to orientate away from shore using wave cues to guide them out to sea. Artificial light may interfere with this process, but the relative importance of natural and anthropogenic cues to the dispersal of hatchlings is unknown. Here, we used acoustic telemetry to track the movement of flatback turtle (Natator depressus) hatchlings dispersing through nearshore waters. Turtles dispersed in the presence and absence of artificial light through a receiver array where a range of oceanographic variables were measured. Turtle tracks were analysed using a full subsets Generalised Additive Mixed Model approach to identify the most important cues influencing the bearing, variance in bearing (a measure of the ability to orientate directly), rate of travel and time spent in the array. Artificial light reduced their swim speed by up to 30%, increased the amount of time spent in nearshore waters (by 50–150%) and increased the variance in bearing (100–180% more variable), regardless of oceanographic conditions. Under ambient conditions, ocean currents affected the bearing of hatchlings as they left the shore, but when light was present, this effect was diminished, showing turtles actively swam against currents in their attempts to move towards light. After accounting for the effects of currents on hatchlings dispersing under ambient conditions, turtles swam offshore by moving perpendicular to the coastline and did not appear to orient into incident wave direction. Overall, light disrupted the dispersal of hatchlings causing them to linger, become disoriented in the near shore and expend energy swimming against ocean currents.  
  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 0171-8630 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1967  
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Author Kumar, J.; Malik, S.; Bhardwaj, S.K.; Rani, S. url  doi
openurl 
  Title Bright light at night alters the perception of daylength in Indian weaver bird (Ploceus philippinus) 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 488-496  
  Keywords (up) Animals  
  Abstract The brighter nights have posed new challenges to the wild species by affecting their temporal physiology. The present study on Indian weaver bird (Ploceus philippinus) investigated if exposure to bright light at different phases of night affects their clock-mediated daily functions. Birds were placed individually in specially designed activity cages under short days and long nights (8L:16D; L = 100 lux, D < 0.1 lux) for approximately 3 weeks (19 days). Thereafter, they were divided into four groups (n = 6-9), and given approximately 2 lux light either for the entire night (ZT 08-24; zeitgeber time 0 = time of light on; pattern A) or for 4 hr (pattern B), placed in 16 hr night such that its onset coincides with the onset of night (early night group, ZT 08-12), its end with the end of night (late night group, ZT 20-24), or the night was interrupted in the middle (midnight group, ZT 14-18). The results showed that bright light in entire night induced early onset of day activity and fragmented rest at night, however, if given at different phases of night, it made the days longer by delaying end (early night group) or advancing onset of daily activity (late night group). It also suppressed the melatonin levels and increased body temperature. These results suggest that bright light at night alters the perception of daylength and affects the underlying physiology. The findings may be useful in adopting a strategy for use of night light without disturbing species fitness in their environment.  
  Address Department of Zoology, University of Lucknow, Lucknow, India  
  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 2471-5638 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30043408 Approved no  
  Call Number GFZ @ kyba @ Serial 1971  
Permanent link to this record
 

 
Author Konkal, P.; Ganesh, C.B. url  doi
openurl 
  Title Exposure to low or high light intensity affects pituitary-testicular activity in the fish Oreochromis mossambicus Type Journal Article
  Year 2018 Publication Aquaculture Abbreviated Journal Aquaculture  
  Volume 497 Issue Pages 109-116  
  Keywords (up) Animals  
  Abstract Light is an important factor for the successful reproduction of most fish. In this investigation, effect of different light intensities on pituitary-testis axis was studied for a period of 21 days, under normal photoperiodic regime in the tilapia Oreochromis mossambicus. The mean numbers of spermatogonia (Sg), primary spermatocytes (Ps), secondary spermatocytes (Ss), early spermatids (Est) and late spermatids (Lst) did not show significant difference between fish exposed to moderate light intensity (MLI) and initial controls or controls, whereas the mean numbers of Sg were significantly lower in fish exposed to low light intensity (LLI) compared to those of initial controls, controls and MLI groups. However, the mean numbers of Ps, Ss, Est and Lst were significantly lower in fish exposed to LLI and high light intensity (HLI) compared to those of other experimental groups. Furthermore, in the pituitary gland, weakly immunoreactive luteinizing hormone (LH) secreting cells were observed in the proximal pars distalis (PPD) region in fish exposed to LLI and HLI in contrast to the intense immunolabelling of these cells in initial controls, controls and MLI groups. The androgen receptors showed diminished immunoreactivity in the Sertoli cells along the seminiferous lobules of the testis in fish exposed to LLI and HLI, whereas the strongly immunoreactive androgen receptors were observed in the Sertoli cells in initial controls, controls and MLI groups. Taken together, these results indicate that long-term exposure to low or high light intensity light suppresses spermatogenetic process and that this inhibition is due to reduced secretory activity of LH cells in the pituitary gland and androgen secretion in the testis of the fish O. mossambicus.  
  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 0044-8486 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1974  
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