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Author Flores, D.E.F.L.; Jannetti, M.G.; Valentinuzzi, V.S.; Oda, G.A. url  doi
openurl 
  Title Entrainment of circadian rhythms to irregular light/dark cycles: a subterranean perspective Type Journal Article
  Year 2016 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 6 Issue Pages 34264  
  Keywords (up) Animals  
  Abstract Synchronization of biological rhythms to the 24-hour day/night has long been studied with model organisms, under artificial light/dark cycles in the laboratory. The commonly used rectangular light/dark cycles, comprising hours of continuous light and darkness, may not be representative of the natural light exposure for most species, including humans. Subterranean rodents live in dark underground tunnels and offer a unique opportunity to investigate extreme mechanisms of photic entrainment in the wild. Here, we show automated field recordings of the daily light exposure patterns in a South American subterranean rodent, the tuco-tuco (Ctenomys aff. knighti ). In the laboratory, we exposed tuco-tucos to a simplified version of this natural light exposure pattern, to determine the minimum light timing information that is necessary for synchronization. As predicted from our previous studies using mathematical modeling, the activity rhythm of tuco-tucos synchronized to this mostly simplified light/dark regimen consisting of a single light pulse per day, occurring at randomly scattered times within a day length interval. Our integrated semi-natural, lab and computer simulation findings indicate that photic entrainment of circadian oscillators is robust, even in face of artificially reduced exposure and increased phase instability of the synchronizing stimuli.  
  Address Institute of Biosciences, Department of Physiology, University of Sao Paulo; Sao Paulo, Sao Paulo, 05508-900; Brazil  
  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:27698436 Approved no  
  Call Number LoNNe @ kyba @ Serial 1539  
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Author Liefting, M.; Cosijn, J.; Ellers, J. url  doi
openurl 
  Title Synergistic effect of daily temperature fluctuations and matching light-dark cycle enhances population growth and synchronizes oviposition behavior in a soil arthropod Type Journal Article
  Year 2016 Publication Journal of Insect Physiology Abbreviated Journal Journal of Insect Physiology  
  Volume 96 Issue in press Pages 108-114  
  Keywords (up) Animals  
  Abstract Some major aspects of insect life, like development time and reproduction, can benefit from fluctuating temperatures rather than a constant temperature regime. The benefit of fluctuating temperature has generally been attributed to the non-linear properties of the relationship of many life history traits with temperature. Daily temperature rise, however, usually coincide with the light phase of the photoperiodic cycle and there could be a benefit in linking daily temperature fluctuations with light and dark phases e.g. to anticipate the change in temperature. Such synergistic effects have primarily been studied in the light of activity patterns and gene expression, but have not yet been shown to extend to population dynamics and aspects of individual fitness like oviposition behavior. We therefore explored possible synergistic effects on life history traits of the springtail Orchesella cincta. We first test the primary effect of ecologically relevant temperature fluctuations of different amplitudes on population growth and total population mass. The slowest population growth was observed in the constant temperature regime treatment and the highest population growth in the regime with high amplitude fluctuations. In a second experiment, population growth and oviposition rhythm were measured under four different regimes; a constant light and temperature regime, thermoperiod only, photoperiod only and thermoperiod and photoperiod aligned as under natural conditions. The regime in which thermoperiod was aligned with photoperiod resulted in a higher population growth than could be realized by either factor alone. Also, significantly fewer eggs were laid in the constant temperature/light regime than in the other three regimes, strongly suggesting that this regime is stressful to O. cincta. Additionally, the fraction of eggs laid at night was highest in the regime with the combined temperature and light cycle. In conclusion, our results show that under these experimental conditions there is a synergistic effect of daily temperature fluctuations in combination with light/dark phases that can considerably influence important life history traits and affect behavior. Such effects are likely to be relevant under natural conditions.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-1910 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1542  
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Author Raap, T.; Casasole, G.; Costantini, D.; AbdElgawad, H.; Asard, H.; Pinxten, R.; Eens, M. url  doi
openurl 
  Title Artificial light at night affects body mass but not oxidative status in free-living nestling songbirds: an experimental study Type Journal Article
  Year 2016 Publication Scientific Reports Abbreviated Journal Sci. Rep.  
  Volume 6 Issue Pages 35626  
  Keywords (up) Animals  
  Abstract Artificial light at night (ALAN), termed light pollution, is an increasingly important anthropogenic environmental pressure on wildlife. Exposure to unnatural lighting environments may have profound effects on animal physiology, particularly during early life. Here, we experimentally investigated for the first time the impact of ALAN on body mass and oxidative status during development, using nestlings of a free-living songbird, the great tit (Parus major), an important model species. Body mass and blood oxidative status were determined at baseline (=13 days after hatching) and again after a two night exposure to ALAN. Because it is very difficult to generalise the oxidative status from one or two measures we relied on a multi-biomarker approach. We determined multiple metrics of both antioxidant defences and oxidative damage: molecular antioxidants GSH, GSSG; antioxidant enzymes GPX, SOD, CAT; total non-enzymatic antioxidant capacity and damage markers protein carbonyls and TBARS. Light exposed nestlings showed no increase in body mass, in contrast to unexposed individuals. None of the metrics of oxidative status were affected. Nonetheless, our study provides experimental field evidence that ALAN may negatively affect free-living nestlings’ development and hence may have adverse consequences lasting throughout adulthood.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1543  
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Author Foster, J.G.; Algera, D.A.; Brownscombe, J.W.; Zolderdo, A.J.; Cooke, S.J. url  doi
openurl 
  Title Consequences of Different Types of Littoral Zone Light Pollution on the Parental Care Behaviour of a Freshwater Teleost Fish Type Journal Article
  Year 2016 Publication Water, Air, & Soil Pollution Abbreviated Journal Water Air Soil Pollut  
  Volume 227 Issue 11 Pages  
  Keywords (up) Animals  
  Abstract Ecological light pollution occurs when artificial lights disrupt the natural regimes of individual organisms or their ecosystems. Increasing development of shoreline habitats leads to increased light pollution (e.g., from cottages, docks, automobile traffic), which could impact the ecology of littoral zones of lakes and rivers. Smallmouth bass (Micropterus dolomieu) engage in sole paternal care, guarding their nest continually, day and night, to protect their developing offspring. Any alterations to their behaviour—either directly because of the response to light or indirectly due to changes in nest predator activity and associated response of the bass—could lead to increased energetic demands for fish that have a fixed energy budget and ultimately reduce reproductive success. To examine this issue, tri-axial accelerometer biologgers were externally attached to nesting smallmouth bass during the egg stage to determine whether light pollution (i.e., dock lights with low levels of continuous light and spotlights with high intensity irregular light simulating automobile traffic) altered behaviour of nesting males relative to control fish. Our study revealed that both types of light pollution increased overall bass activity level compared with the control group. The intermittent light treatment group had the highest activity and exhibited large fluctuations between night and day activity levels. Fish in the continual light treatment group displayed statistically higher activity than the control fish but showed limited fluctuations between day and night activity levels. Our results suggest that continuous or intermittent light sources, common in shoreline habitats that have been developed, have the potential to alter the behaviour and thus energy use of nest-guarding fish. This study contributes to the growing body of literature on the ecological consequences of light pollution in aquatic ecosystems.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0049-6979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kyba @ Serial 1545  
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Author Jan Stenvers, D.; van Dorp, R.; Foppen, E.; Mendoza, J.; Opperhuizen, A.-L.; Fliers, E.; Bisschop, P.H.; Meijer, J.H.; Kalsbeek, A.; Deboer, T. url  doi
openurl 
  Title Dim light at night disturbs the daily sleep-wake cycle in the rat Type Journal Article
  Year 2016 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 6 Issue Pages 35662  
  Keywords (up) Animals  
  Abstract Exposure to light at night (LAN) is associated with insomnia in humans. Light provides the main input to the master clock in the hypothalamic suprachiasmatic nucleus (SCN) that coordinates the sleep-wake cycle. We aimed to develop a rodent model for the effects of LAN on sleep. Therefore, we exposed male Wistar rats to either a 12 h light (150-200lux):12 h dark (LD) schedule or a 12 h light (150-200 lux):12 h dim white light (5 lux) (LDim) schedule. LDim acutely decreased the amplitude of daily rhythms of REM and NREM sleep, with a further decrease over the following days. LDim diminished the rhythms of 1) the circadian 16-19 Hz frequency domain within the NREM sleep EEG, and 2) SCN clock gene expression. LDim also induced internal desynchronization in locomotor activity by introducing a free running rhythm with a period of ~25 h next to the entrained 24 h rhythm. LDim did not affect body weight or glucose tolerance. In conclusion, we introduce the first rodent model for disturbed circadian control of sleep due to LAN. We show that internal desynchronization is possible in a 24 h L:D cycle which suggests that a similar desynchronization may explain the association between LAN and human insomnia.  
  Address Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, 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 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:27762290 Approved no  
  Call Number LoNNe @ kyba @ Serial 1547  
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