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Author Scheuermaier, K.; Munch, M.; Ronda, J.M.; Duffy, J.F. url  doi
openurl 
  Title Improved cognitive morning performance in healthy older adults following blue-enriched light exposure on the previous evening Type Journal Article
  Year 2018 Publication Behavioural Brain Research Abbreviated Journal Behav Brain Res  
  Volume (down) 348 Issue Pages 267-275  
  Keywords Human Health  
  Abstract OBJECTIVES: Exposure to light can have acute alerting and circadian phase-shifting effects. This study investigated the effects of evening exposure to blue-enriched polychromatic white (BEL) vs. polychromatic white light (WL) on sleep inertia dissipation the following morning in older adults. METHODS: Ten healthy older adults (average age=63.3 yrs; 6F) participated in a 13-day study comprising three baseline days, an initial circadian phase assessment, four days with 2-h evening light exposures, a post light exposure circadian phase assessment and three recovery days. Participants were randomized to either BEL or WL of the same irradiance for the four evening light exposures. On the next mornings at 2, 12, 22 and 32min after each wake time, the participants completed a 90-s digit-symbol substitution test (DSST) to assess working memory, and objective alertness was assessed using a wake EEG recording. DSST and power density from the wake EEG recordings were compared between the two groups. RESULTS: DSST performance improved with time awake (p<0.0001) and across study days in both light exposure groups (p<0.0001). There was no main effect of group, although we observed a significant day x group interaction (p=0.0004), whereby participants exposed to BEL performed significantly better on the first two mornings after light exposures than participants in WL (post-hoc, p<0.05). On those days, the BEL group showed higher EEG activity in some of the frequency bins in the sigma and beta range (p<0.05) on the wake EEG. CONCLUSION: Exposure to blue-enriched white light in the evening significantly improved DSST performance the following morning when compared to polychromatic white light. This was associated with a higher level of objective alertness on the wake EEG, but not with changes in sleep or circadian timing.  
  Address Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Boston, MA, United States; Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States  
  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 0166-4328 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29684473 Approved no  
  Call Number GFZ @ kyba @ Serial 1899  
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Author Souman, J.L.; Tinga, A.M.; Te Pas, S.F.; van Ee, R.; Vlaskamp, B.N.S. url  doi
openurl 
  Title Acute alerting effects of light: a systematic literature review Type Journal Article
  Year 2018 Publication Behavioural Brain Research Abbreviated Journal Behav Brain Res  
  Volume (down) 337 Issue Pages 228-239  
  Keywords Human Health  
  Abstract Periodic, well timed exposure to light is important for our health and wellbeing. Light, in particular in the blue part of the spectrum, is thought to affect alertness both indirectly, by modifying circadian rhythms, and directly, giving rise to acute effects. We performed a systematic review of empirical studies on direct, acute effects of light on alertness to evaluate the reliability of these effects and to assess to what extent they depend on other factors, such as time of day, exposure duration and sleep pressure. In total, we identified 74 studies in which either light intensity, spectral distribution, or both were manipulated, and the effects on behavioral measures of alertness were evaluated, either subjectively or measured in performance tasks. The results show that increasing the intensity or the color temperature of polychromatic white light in general has been found to increase subjective ratings of alertness, though a substantial proportion of these studies failed to find significant effects. There is little evidence in the literature that these subjective alerting effects of light also translate into improvements on performance measures of alertness. For monochromatic or narrowband light exposure, some studies have shown improvement in reaction time tasks with exposure to blue light, but generally this was not accompanied by changes in subjective alertness. Thus, the alerting effects of light are far less clear than often suggested. We suggest that in future studies more attention should be paid to other factors that may influence the effects of light, such as chronotype, circadian phase, homeostatic state and prior light history.  
  Address Philips Research (Department Brain, Behavior & Cognition), Eindhoven, 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 0166-4328 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:28912014 Approved no  
  Call Number LoNNe @ kyba @ Serial 1727  
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Author Bharti, N.; Tatem, A.J.; Ferrari, M.J.; Grais, R.F.; Djibo, A.; Grenfell, B.T. url  doi
openurl 
  Title Explaining seasonal fluctuations of measles in Niger using nighttime lights imagery Type Journal Article
  Year 2011 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume (down) 334 Issue 6061 Pages 1424-1427  
  Keywords Remote Sensing; Human Health; Cities; Emigration and Immigration; Epidemics; *Epidemiologic Methods; Humans; Light; Measles/*epidemiology/transmission; Niger/epidemiology; *Population Density; Remote Sensing Technology; *Seasons; Spacecraft  
  Abstract Measles epidemics in West Africa cause a significant proportion of vaccine-preventable childhood mortality. Epidemics are strongly seasonal, but the drivers of these fluctuations are poorly understood, which limits the predictability of outbreaks and the dynamic response to immunization. We show that measles seasonality can be explained by spatiotemporal changes in population density, which we measure by quantifying anthropogenic light from satellite imagery. We find that measles transmission and population density are highly correlated for three cities in Niger. With dynamic epidemic models, we demonstrate that measures of population density are essential for predicting epidemic progression at the city level and improving intervention strategies. In addition to epidemiological applications, the ability to measure fine-scale changes in population density has implications for public health, crisis management, and economic development.  
  Address Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA. nbharti@princeton.edu  
  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 0036-8075 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22158822; PMCID:PMC3891598 Approved no  
  Call Number GFZ @ kyba @ Serial 2770  
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Author Czeisler, C.A.; Shanahan, T.L.; Klerman, E.B.; Martens, H.; Brotman, D.J.; Emens, J.S.; Klein, T.; Rizzo, J.F. 3rd url  doi
openurl 
  Title Suppression of melatonin secretion in some blind patients by exposure to bright light Type Journal Article
  Year 1995 Publication The New England Journal of Medicine Abbreviated Journal N Engl J Med  
  Volume (down) 332 Issue 1 Pages 6-11  
  Keywords Human Health; Adolescent; Adult; Aged; Blindness/etiology/*physiopathology; Circadian Rhythm; Female; Humans; *Light; Male; Melatonin/blood/*secretion; Middle Aged; Photic Stimulation; Sleep Initiation and Maintenance Disorders/physiopathology; Visual Perception  
  Abstract BACKGROUND: Complete blindness generally results in the loss of synchronization of circadian rhythms to the 24-hour day and in recurrent insomnia. However, some blind patients maintain circadian entrainment. We undertook this study to determine whether some blind patients' eyes convey sufficient photic information to entrain the hypothalamic circadian pacemaker and suppress melatonin secretion, despite an apparently complete loss of visual function. METHODS: We evaluated the input of light to the circadian pacemaker by testing the ability of bright light to decrease plasma melatonin concentrations in 11 blind patients with no conscious perception of light and in 6 normal subjects. We also evaluated circadian entrainment over time in the blind patients. RESULTS: Plasma melatonin concentrations decreased during exposure to bright light in three sightless patients by an average (+/- SD) of 69 +/- 21 percent and in the normal subjects by an average of 66 +/- 15 percent. When two of these blind patients were tested with their eyes covered during exposure to light, plasma melatonin did not decrease. The three blind patients reported no difficulty sleeping and maintained apparent circadian entrainment to the 24-hour day. Plasma melatonin concentrations did not decrease during exposure to bright light in seven of the remaining blind patients; in the eighth, plasma melatonin was undetectable. These eight patients reported a history of insomnia, and in four the circadian temperature rhythm was not entrained to the 24-hour day. CONCLUSIONS: The visual subsystem that mediates light-induced suppression of melatonin secretion remains functionally intact in some sightless patients. The absence of photic input to the circadian system thus constitutes a distinct form of blindness, associated with periodic insomnia, that afflicts most but not all patients with no conscious perception of light.  
  Address Department of Medicine, Harvard Medical School, Boston, MA 02115  
  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 0028-4793 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:7990870 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 732  
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Author Middleton, B.; Stone, B.M.; Arendt, J. url  doi
openurl 
  Title Human circadian phase in 12:12 h, 200:<8 lux and 1000:<8 lux light-dark cycles, without scheduled sleep or activity Type Journal Article
  Year 2002 Publication Neuroscience Letters Abbreviated Journal Neuroscience Letters  
  Volume (down) 329 Issue 1 Pages 41-44  
  Keywords Human Health  
  Abstract The light levels required to maintain human circadian phase in the absence of other strong time cues are not defined. We investigated circadian phase in two groups of men, living in partial temporal isolation, exposed to 12 h:12 h light:dark cycles of: (A) 200:<8 lux, broad spectrum white light for 14 days; and (B) 1000:<8lux for 14 days. The rhythm variables measured were urinary 6-sulphatoxymelatonin, rectal temperature, activity and rest (actigraphy and sleep logs). In 200:<8 lux four/six individuals showed phase delays. Exposure to 1000:<8 lux appeared to maintain synchronisation of rest-activity to 24 h, but with a significant overall phase advance of 0.81 h in temperature. These observations suggest that domestic intensity light does not maintain phase without scheduled sleep/activity, possibly due to indirect effects on behaviour influencing light exposure.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3940 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2247  
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