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Author Foster, J.J.; Kirwan, J.D.; El Jundi, B.; Smolka, J.; Khaldy, L.; Baird, E.; Byrne, M.J.; Nilsson, D.-E.; Johnsen, S.; Dacke, M. url  doi
openurl 
  Title Orienting to polarized light at night – matching lunar skylight to performance in a nocturnal beetle Type Journal Article
  Year 2019 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume 222 Issue Pt 2 Pages  
  Keywords Animals; Natural skylight  
  Abstract For polarized light to inform behaviour, the typical range of degrees of polarization observable in the animal's natural environment must be above the threshold for detection and interpretation. Here, we present the first investigation of the degree of linear polarization threshold for orientation behaviour in a nocturnal species, with specific reference to the range of degrees of polarization measured in the night sky. An effect of lunar phase on the degree of polarization of skylight was found, with smaller illuminated fractions of the moon's surface corresponding to lower degrees of polarization in the night sky. We found that the South African dung beetle Escarabaeus satyrus can orient to polarized light for a range of degrees of polarization similar to that observed in diurnal insects, reaching a lower threshold between 0.04 and 0.32, possibly as low as 0.11. For degrees of polarization lower than 0.23, as measured on a crescent moon night, orientation performance was considerably weaker than that observed for completely linearly polarized stimuli, but was nonetheless stronger than in the absence of polarized light.  
  Address Lund Vision Group, Department of Biology, Lund University, Solvegatan 35, 223 62 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 0022-0949 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30530838 Approved no  
  Call Number GFZ @ kyba @ Serial (down) 2599  
Permanent link to this record
 

 
Author Langbehn, T.; Aksnes, D.; Kaartvedt, S.; Fiksen, Ø.; Jørgensen, C. url  doi
openurl 
  Title Light comfort zone in a mesopelagic fish emerges from adaptive behaviour along a latitudinal gradient Type Journal Article
  Year 2019 Publication Marine Ecology Progress Series Abbreviated Journal Mar. Ecol. Prog. Ser.  
  Volume 623 Issue Pages 161-174  
  Keywords Animals; Moonlight  
  Abstract Throughout the oceans, small fish and other micronekton migrate between daytimedepths of several hundred meters and near-surface waters at night. These diel vertical migrationsof mesopelagic organisms structure pelagic ecosystems through trophic interactions, and are akey element in the biological carbon pump. However, depth distributions and migration ampli-tude vary greatly. Suggested proximate causes of the migration such as oxygen, temperature, andlight often correlate and therefore the causal underpinnings have remained unclear. Using meso-pelagic fishes and the Norwegian Sea as a study system, we developed a dynamic state variablemodel that finds optimal migration patterns that we validate with acoustic observations along alatitudinal gradient. The model describes predation risk and bioenergetics, and maximizes ex -pected energy surplus, a proxy for Darwinian fitness. The model allows us to disentangle the driv-ers of migration and make predictions about depth distribution and related fitness consequencesalong a latitudinal trajectory with strong gradients in environmental drivers and vertical distribu-tion of scattering layers. We show that the model-predicted vertical migration of mesopelagicfishes matches that observed along this transect. For most situations, modelled mesopelagic fishbehaviour can be well described by a light comfort zone near identical to that derived from obser-vations. By selectively keeping light or temperature constant, the model reveals that temperature,in comparison with light, has little effect on depth distribution. We find that water clarity, whichlimits how deeply light can penetrate into the ocean, structures daytime depths, while surfacelight at night controlled the depth of nocturnal ascents.  
  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 (down) 2598  
Permanent link to this record
 

 
Author Stone, J.E.; Phillips, A.J.K.; Ftouni, S.; Magee, M.; Howard, M.; Lockley, S.W.; Sletten, T.L.; Anderson, C.; Rajaratnam, S.M.W.; Postnova, S. url  doi
openurl 
  Title Generalizability of A Neural Network Model for Circadian Phase Prediction in Real-World Conditions Type Journal Article
  Year 2019 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 9 Issue 1 Pages 11001  
  Keywords Human Health  
  Abstract A neural network model was previously developed to predict melatonin rhythms accurately from blue light and skin temperature recordings in individuals on a fixed sleep schedule. This study aimed to test the generalizability of the model to other sleep schedules, including rotating shift work. Ambulatory wrist blue light irradiance and skin temperature data were collected in 16 healthy individuals on fixed and habitual sleep schedules, and 28 rotating shift workers. Artificial neural network models were trained to predict the circadian rhythm of (i) salivary melatonin on a fixed sleep schedule; (ii) urinary aMT6s on both fixed and habitual sleep schedules, including shift workers on a diurnal schedule; and (iii) urinary aMT6s in rotating shift workers on a night shift schedule. To determine predicted circadian phase, center of gravity of the fitted bimodal skewed baseline cosine curve was used for melatonin, and acrophase of the cosine curve for aMT6s. On a fixed sleep schedule, the model predicted melatonin phase to within +/- 1 hour in 67% and +/- 1.5 hours in 100% of participants, with mean absolute error of 41 +/- 32 minutes. On diurnal schedules, including shift workers, the model predicted aMT6s acrophase to within +/- 1 hour in 66% and +/- 2 hours in 87% of participants, with mean absolute error of 63 +/- 67 minutes. On night shift schedules, the model predicted aMT6s acrophase to within +/- 1 hour in 42% and +/- 2 hours in 53% of participants, with mean absolute error of 143 +/- 155 minutes. Prediction accuracy was similar when using either 1 (wrist) or 11 skin temperature sensor inputs. These findings demonstrate that the model can predict circadian timing to within +/- 2 hours for the vast majority of individuals on diurnal schedules, using blue light and a single temperature sensor. However, this approach did not generalize to night shift conditions.  
  Address School of Physics, University of Sydney, Sydney, New South Wales, Australia  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:31358781; PMCID:PMC6662750 Approved no  
  Call Number GFZ @ kyba @ Serial (down) 2597  
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Author Kim, K.‐N.; Sin, U.‐C.; Jo, Y.‐C.; Huang, Z.‐J.; Hassan, A.; Huang, Q.‐Y.; Lei, C.‐L. url  doi
openurl 
  Title Influence of green light at night on Juvenile hormone in the oriental armywormMythimna separata(Lepidoptera: Noctuidae) Type Journal Article
  Year 2019 Publication Physiological Entomology Abbreviated Journal Physiol. Entomol.  
  Volume in press Issue Pages  
  Keywords Animals  
  Abstract The oriental armyworm Mythimna separata is an agricultural insect pest in Eastern Asia. Mythimna separata moths have a high phototactic response to green (520 nm) light. The biological characteristics of insects living under light of a specific wavelength at night can change and, accordingly, Juvenile hormone (JH) levels may be influenced by this light. The present study evaluates changes in the total JH levels at different developmental stages (larvae, pupae and adults) of M. separata reared under green light with different exposure periods at night (or dark period). The results show that, when the exposure time per day of the green light at night is extended, the JH levels in the final‐instar larvae (22 days) and older age pupae (8 days) are significantly reduced, and the JH levels in earlier age pupae (4 days) and adults (3, 6 and 9 days) are significantly increased, compared with groups not exposed to green light. Additionally, the JH level of male moths significantly differs from that of the female moths. We suggest that the JH level of M. separata insects could be regulated by the green light at night (or dark period). The findings of the present study will help to explain the relationship between the light environment and biological characteristics in nocturnal moths.  
  Address  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0307-6962 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial (down) 2596  
Permanent link to this record
 

 
Author Spitschan, M.; Cajochen, C. url  doi
openurl 
  Title Binocular facilitation in light-mediated melatonin suppression? Type Journal Article
  Year 2019 Publication Journal of Pineal Research Abbreviated Journal J Pineal Res  
  Volume in press Issue Pages  
  Keywords Human Health  
  Abstract Astronomers and pilots have known for a long time that closing one eye can preserve vision in that eye while going from dark to light and back. Recently, it was reported that viewing a smartphone monocularly in an otherwise dark room can lead to transient, but strong reductions in retinal sensitivity in that eye (Alim-Marvasti, Bi, Mahroo, Barbur, & Plant, 2016). But seeing detail is not the only function that is mediated by the retina. Here, we address the question whether light exposure to one eye only (monocular) has tangible effects on the suppression of melatonin by light, relative to both eyes open (binocular). This article is protected by copyright. All rights reserved.  
  Address Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Basel, Switzerland  
  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 0742-3098 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:31361918 Approved no  
  Call Number GFZ @ kyba @ Serial (down) 2595  
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