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Author Dacke, M.; Byrne, M.J.; Baird, E.; Scholtz, C.H.; Warrant, E.J. url  doi
openurl 
  Title How dim is dim? Precision of the celestial compass in moonlight and sunlight Type Journal Article
  Year 2011 Publication Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences Abbreviated Journal Philos Trans R Soc Lond B Biol Sci  
  Volume (down) 366 Issue 1565 Pages 697-702  
  Keywords Animals; Beetles/*physiology; Behavior, Animal; *Moon; *Sunlight; Video Recording  
  Abstract Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim--and the polarization pattern too weak--to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision.  
  Address Department of Biology, University of Lund, Helgonavagen 3, 223 62 Lund, Sweden. marie.dacke@cob.lu.se  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0962-8436 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:21282173; PMCID:PMC3049003 Approved no  
  Call Number IDA @ john @ Serial 34  
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Author Xavier Kerola, D. url  doi
openurl 
  Title Modelling artificial night-sky brightness with a polarized multiple scattering radiative transfer computer code: Modelling artificial night-sky brightness Type Journal Article
  Year 2006 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal  
  Volume (down) 365 Issue 4 Pages 1295-1299  
  Keywords Skyglow; modeling; radiative transfer; Gauss-Seidel; light pollution; Garstang model  
  Abstract As part of an ongoing investigation of radiative effects produced by hazy atmospheres, computational procedures have been developed for use in determining the brightening of the night sky as a result of urban illumination. The downwardly and upwardly directed radiances of multiply scattered light from an offending metropolitan source are computed by a straightforward Gauss-Seidel (G-S) iterative technique applied directly to the integrated form of Chandrasekhar's vectorized radiative transfer equation. Initial benchmark night-sky brightness tests of the present G-S model using fully consistent optical emission and extinction input parameters yield very encouraging results when compared with the double scattering treatment of Garstang, the only full-fledged previously available model.  
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  Series Editor Series Title Abbreviated Series Title  
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  ISSN 0035-8711 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 278  
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Author Datta, S.; Samanta, D.; Tiwary, B.; Chaudhuri, A.G.; Chakrabarti, N. url  doi
openurl 
  Title Sex and estrous cycle dependent changes in locomotor activity, anxiety and memory performance in aged mice after exposure of light at night Type Journal Article
  Year 2019 Publication Behavioural Brain Research Abbreviated Journal Behav Brain Res  
  Volume (down) 365 Issue Pages 198-209  
  Keywords Animals; mouse models; locomotor activities  
  Abstract Light-at-night (LAN) can affect mammalian behaviour. But, the effects of LAN on aged rodents remain undefined yet. In the present investigation, aged Swiss Albino mice, habituated in regular light-dark cycle, were exposed to bright-light-pulse (1-hr) at night on the day of study followed by experimentations for assessment of locomotor activities in the open field, anxiety in the elevated plus maze and short-term memory for novel object recognition (NOR) in the habituated field. Under without-bright-light exposure, (a) aged proestrous females showed greater locomotor activities and less anxiety than in aged diestrous females, (b) aged males showed locomotor activities and anxiety level similar to aged diestrous females and aged proestrous females respectively and (c) all animals failed to retain in object discrimination memory. LAN exposure exhibited the continual failure of such retention of memory while animals showed free and spontaneous exploration with thigmotactic behaviour having no object bias and/or phobia, but time stay in objects by animals altered variably among sexes and stages of estrous cycle. Overall, the LAN caused (a) diminution in locomotor activities, rise in anxiety and failure of memory for recognition of both familiar and novel objects in aged proestrous females, (b) hyperlocomotor activities and reduction in anxiety in both males and diestrous females with the failure of memory for recognition of novel objects only in aged males while diestrous females showed enhanced exploration time to both objects during NOR. Thus, nocturnal behaviour of aged mice varies with sex and estrous cycle and light acts differentially on them.  
  Address University of Calcutta, Department of Physiology, 92, APC Road, Kolkata, 700009, West Bengal, India. Electronic address: ncphysiolcu@gmail.com  
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  Series Volume Series Issue Edition  
  ISSN 0166-4328 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30853396 Approved no  
  Call Number GFZ @ kyba @ Serial 2259  
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Author Shlesinger, T.; Loya, Y. url  doi
openurl 
  Title Breakdown in spawning synchrony: A silent threat to coral persistence Type Journal Article
  Year 2019 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume (down) 365 Issue 6457 Pages 1002-1007  
  Keywords Animals; Coral  
  Abstract The impacts of human and natural disturbances on coral reefs are typically quantified through visible damage (e.g., reduced coral coverage as a result of bleaching events), but changes in environmental conditions may also cause damage in less visible ways. Despite the current paradigm, which suggests consistent, highly synchronized spawning events, corals that reproduce by broadcast spawning are particularly vulnerable because their reproductive phenology is governed by environmental cues. Here, we quantify coral spawning intensity during four annual reproductive seasons, alongside laboratory analyses at the polyp, colony, and population levels, and we demonstrate that, compared with historical data, several species from the Red Sea have lost their reproductive synchrony. Ultimately, such a synchrony breakdown reduces the probability of successful fertilization, leading to a dearth of new recruits, which may drive aging populations to extinction.  
  Address School of Zoology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel  
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  Series Volume Series Issue Edition  
  ISSN 0036-8075 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:31488683 Approved no  
  Call Number GFZ @ kyba @ Serial 2673  
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Author Wiltschko, W.; Munro, U.; Ford, H.; Wiltschko, R. url  doi
openurl 
  Title Red light disrupts magnetic orientation of migratory birds Type Journal Article
  Year 1993 Publication Nature Abbreviated Journal Nature  
  Volume (down) 364 Issue 6437 Pages 525-527  
  Keywords magnetoreception; birds; animals  
  Abstract The transduction mechanisms and the neurophysiological basis of magnetoreception in birds are still largely unexplained, even though the role of the magnetic compass in the orientation of birds is fairly well understood. The discussion on magnetoreception in birds and terrestrial vertebrates focuses mainly on two mechanisms: small particles of magnetite and biochemical bi-radical reactions of excited macromolecules. When the bi-radical hypothesis was first proposed, magnetic resonance phenomena in the retina were suggested as the primary processes, which led to the question of whether magnetoreception was light-dependent. Homing experiments and electrophysiological evidence from pigeons have produced evidence consistent with such a mechanism. An effect of the spectral composition of light on magnetic compass orientation in amphibians has recently been described: under blue light of 450 nm and below, newts oriented as they did under the full spectrum, whereas they showed a roughly 90° counterclockwise shift when tested under wavelengths at or above 500 nm. Here we report the first orientation tests on migratory birds under light of different wavelengths; the results suggest a light-dependent process that appears to differ from that reported in newts.  
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  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 58  
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