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Author Zukauskas, A.; Vaicekauskas, R.; Vitta, P. url  doi
openurl 
  Title Optimization of solid-state lamps for photobiologically friendly mesopic lighting Type Journal Article
  Year 2012 Publication Applied Optics Abbreviated Journal Appl Opt  
  Volume 51 Issue 35 Pages 8423-8432  
  Keywords Lighting Systems; Circadian Rhythm; Color; Equipment Design; Humans; Light; *Lighting; Melatonin/metabolism; Photobiology/*methods; Semiconductors; Time Factors; Vision, Ocular  
  Abstract (up) The circadian and visual-performance-based mesopic systems of photometry were applied for the optimization of the spectral power distributions (SPDs) of the solid-state sources of light for low-illuminance lighting applications. At mesopic adaptation luminances typical of outdoor lighting (0.1-2 cd/m(2)), the optimal SPDs were obtained through the minimization of the mesopic circadian action factor, which is the ratio of the circadian efficacy of radiation to mesopic luminous efficacy of radiation. For correlated color temperatures below ~3000 K, the optimized dichromatic light-emitting diodes (LEDs) are shown to pose a lower circadian hazard than high-pressure sodium lamps and common warm white LEDs; also they are potentially more efficacious and have acceptable color rendition properties under mesopic conditions.  
  Address Institute of Applied Research, Vilnius University, Sauletekio al. 9-III, Vilnius LT-10222, Lithuania. arturas.zukauskas@ff.vu.lt  
  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 0003-6935 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23262538 Approved no  
  Call Number LoNNe @ christopher.kyba @ Serial 448  
Permanent link to this record
 

 
Author Kovac, J.; Husse, J.; Oster, H. url  doi
openurl 
  Title A time to fast, a time to feast: the crosstalk between metabolism and the circadian clock Type Journal Article
  Year 2009 Publication Molecules and Cells Abbreviated Journal Mol Cells  
  Volume 28 Issue 2 Pages 75-80  
  Keywords Human Health; Animals; Biological Clocks/*physiology; CLOCK Proteins/genetics/metabolism; Circadian Rhythm/*physiology; Energy Metabolism/*physiology; Gene Expression Regulation; Homeostasis; Humans; Period Circadian Proteins/genetics/metabolism; Time Factors  
  Abstract (up) The cyclic environmental conditions brought about by the 24 h rotation of the earth have allowed the evolution of endogenous circadian clocks that control the temporal alignment of behaviour and physiology, including the uptake and processing of nutrients. Both metabolic and circadian regulatory systems are built upon a complex feedback network connecting centres of the central nervous system and different peripheral tissues. Emerging evidence suggests that circadian clock function is closely linked to metabolic homeostasis and that rhythm disruption can contribute to the development of metabolic disease. At the same time, metabolic processes feed back into the circadian clock, affecting clock gene expression and timing of behaviour. In this review, we summarize the experimental evidence for this bimodal interaction, with a focus on the molecular mechanisms mediating this exchange, and outline the implications for clock-based and metabolic diseases.  
  Address Circadian Rhythms Group, Max Planck Institute of Biophysical Chemistry, 37077, Gottingen, Germany  
  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 1016-8478 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:19714310 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 772  
Permanent link to this record
 

 
Author Santhi, N.; Thorne, H.C.; van der Veen, D.R.; Johnsen, S.; Mills, S.L.; Hommes, V.; Schlangen, L.J.M.; Archer, S.N.; Dijk, D.-J. url  doi
openurl 
  Title The spectral composition of evening light and individual differences in the suppression of melatonin and delay of sleep in humans Type Journal Article
  Year 2012 Publication Journal of Pineal Research Abbreviated Journal J Pineal Res  
  Volume 53 Issue 1 Pages 47-59  
  Keywords Human Health; Adult; *Circadian Clocks; Cross-Sectional Studies; Electroencephalography; Female; Humans; Male; Melatonin/*metabolism; Photic Stimulation; *Photoperiod; Rod Opsins/*metabolism; *Sleep; *Sleep Disorders, Circadian Rhythm/etiology/metabolism/physiopathology; Time Factors  
  Abstract (up) The effect of light on circadian rhythms and sleep is mediated by a multi-component photoreceptive system of rods, cones and melanopsin-expressing intrinsically photosensitive retinal ganglion cells. The intensity and spectral sensitivity characteristics of this system are to be fully determined. Whether the intensity and spectral composition of light exposure at home in the evening is such that it delays circadian rhythms and sleep also remains to be established. We monitored light exposure at home during 6-8wk and assessed light effects on sleep and circadian rhythms in the laboratory. Twenty-two women and men (23.1+/-4.7yr) participated in a six-way, cross-over design using polychromatic light conditions relevant to the light exposure at home, but with reduced, intermediate or enhanced efficacy with respect to the photopic and melanopsin systems. The evening rise of melatonin, sleepiness and EEG-assessed sleep onset varied significantly (P<0.01) across the light conditions, and these effects appeared to be largely mediated by the melanopsin, rather than the photopic system. Moreover, there were individual differences in the sensitivity to the disruptive effect of light on melatonin, which were robust against experimental manipulations (intra-class correlation=0.44). The data show that light at home in the evening affects circadian physiology and imply that the spectral composition of artificial light can be modified to minimize this disruptive effect on sleep and circadian rhythms. These findings have implications for our understanding of the contribution of artificial light exposure to sleep and circadian rhythm disorders such as delayed sleep phase disorder.  
  Address Surrey Sleep Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK. n.santhi@surrey.ac.uk  
  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 0742-3098 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22017511 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 802  
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Author Rockhill, A.P.; DePerno, C.S.; Powell, R.A. url  doi
openurl 
  Title The effect of illumination and time of day on movements of bobcats (Lynx rufus) Type Journal Article
  Year 2013 Publication PloS one Abbreviated Journal PLoS One  
  Volume 8 Issue 7 Pages e69213  
  Keywords Animals; Female; *Lighting; Lynx/*physiology; Male; Moon; Movement/*physiology; North Carolina; Time Factors; Wetlands  
  Abstract (up) Understanding behavioral changes of prey and predators based on lunar illumination provides insight into important life history, behavioral ecology, and survival information. The objectives of this research were to determine if bobcat movement rates differed by period of day (dark, moon, crepuscular, day), lunar illumination (<10%, 10 – <50%, 50 – <90%, >90%), and moon phase (new, full). Bobcats had high movement rates during crepuscular and day periods and low movement rates during dark periods with highest nighttime rates at 10-<50% lunar illumination. Bobcats had highest movement rates during daytime when nighttime illumination was low (new moon) and higher movement rates during nighttime when lunar illumination was high (full moon). The behaviors we observed are consistent with prey availability being affected by light level and by limited vision by bobcats during darkness.  
  Address Fisheries, Wildlife, and Conservation Biology, North Carolina State University, Raleigh, North Carolina, USA. aimee_rockhill@ncsu.edu  
  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 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23861963; PMCID:PMC3704646 Approved no  
  Call Number IDA @ john @ Serial 84  
Permanent link to this record
 

 
Author Kujanik, S.; Mikulecky, M. url  doi
openurl 
  Title Circadian and ultradian extrasystole rhythms in healthy individuals at elevated versus lowland altitudes Type Journal Article
  Year 2010 Publication International Journal of Biometeorology Abbreviated Journal Int J Biometeorol  
  Volume 54 Issue 5 Pages 531-538  
  Keywords Human Health; Acclimatization/physiology; Aged; *Altitude; Anoxia/etiology; Cardiac Complexes, Premature/*physiopathology; Circadian Rhythm/*physiology; Electrocardiography, Ambulatory; Heart Rate/*physiology; Humans; Male; Middle Aged; Reference Values; Time Factors  
  Abstract (up) We defined chronobiologic norms for supraventricular and ventricular single extrasystoles (SV and VE, respectively) in healthy older males in lowland areas. The study was extended to higher altitudes, where hypobaric hypoxia was expected to increase extrasystole frequency, while perhaps not changing rhythmicity. In healthy men (lowland n = 37, altitude n = 22), aged 49-72 years, mean numbers of SVs and VEs were counted over a 24-h period. Cosinor regression was used to test the 24-h rhythm and its 2nd-10th harmonics. The resulting approximating function for either extrasystole type includes its point, 95% confidence interval of the mean, and 95% tolerance for single measurement estimates. Separate hourly differences (delta) between altitude and lowland (n = 59) were also analysed. Hourly means were significantly higher in the mountains versus lowland, by +0.8 beats/h on average for SVs, and by +0.9 beats/h for VEs. A relatively rich chronogram for VEs in mountains versus lowland exists. Delta VEs clearly display a 24-h component and its 2nd, 3rd, 4th and 7th harmonics. This results in significantly higher accumulation of VEs around 8.00 a.m., 11.00 a.m. and 3.00 p.m. in the mountains. The increase in extrasystole occurrence in the mountains is probably caused by higher hypobaric hypoxia and resulting sympathetic drive. Healthy men at elevated altitudes show circadian and several ultradian rhythms of single VEs dependent on the hypoxia level. This new methodological approach--evaluating the differences between two locations using delta values--promises to provide deeper insight into the occurrence of premature beats.  
  Address Dept of Physiology, Faculty of Medicine, Pavol Jozef Safarik University, Trieda SNP 1, 040 66 Kosice, Slovak Republic. stefan.kujanik@upjs.sk  
  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 0020-7128 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:20195873 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 774  
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