209 research outputs found
How to report light exposure in human chronobiology and sleep research experiments (Spitschan, Stefani, Blattner, Gronfier, Lockley & Lucas)
No full textSupplementary information for the article "How to report light exposure in human chronobiology and sleep research experiments" by Spitschan, Stefani, Blattner, Gronfier, Lockley & Lucas
Unen kansanterveydellinen ja yhteiskunnallinen merkitys
No full textFrancesco P. Cappuccio, Michelle A. Miller ja Steven W. Lockley (toim.).
Sleep, Health and Society. From Aetiology to Public Health.
Oxford University Press, Oxford 2010, 488 s
Light-driven model for identifying indicators of non-visual health potential in the built environment
No full textThis thesis introduces a new approach to characterize and evaluate ocular light exposure based on the discovery of novel blue light-sensitive photoreceptors in the human eye. These photoreceptors are the primary mediators of 'non-visual' responses impacting human health, from resetting the circadian clock to directly alerting the brain. In recent years, studies have found that light at short-wavelengths is more effective than light at longer wavelengths at inducing and suppressing a range of 'non-visual' responses. Although it has been recommended that we approximate the spectral sensitivity of these novel photoreceptors with an action spectra peaking near 490 nm, the optimal approach for quantifying non-visual spectral effectiveness is yet unknown. These novel photoreceptors, in addition being photoreceptors themselves, receive inputs from the classical photoreceptors (rods and cones) that in return affect the overall spectral sensitivity of the non-visual system as it changes with lighting conditions. Due to this time-varying spectral sensitivity and the relatively slow temporal processing, the relation between dynamic external light stimuli and the magnitude of non-visual responses cannot be explained with a single function or a simple threshold value. To better understand these non-linear and unknown relations, this thesis aims to develop a novel computational method, based on recent findings about the 'non-visual' - also called non-image-forming - effects of light on human health. A dynamic wavelength-dependent model framework is proposed to evaluate the non-visual health potential of light. This novel approach integrates the spectral effectiveness of irradiation and accommodates time-varying spectral sensitivity functions. These time series of light quantities serve as inputs for the light-driven model, which accounts for light intensity, duration, history, and timing of light exposure. By quantifying light in terms of spectral effectiveness and temporal dynamics, different light exposure patterns can be ranked in terms of its potential to have an impact on human health. The final objective of this thesis is to support the design of healthier buildings by applying evidence-based lighting criteria, which can then inform architectural design through a simulation-based approach. Incorporating non-visual effects into a building simulation workflow requires a good approximation of daylight spectra as it varies with sun position and sky type. Performance predictions must also account for occupant behavior and scheduling, which brings us to the question: How can we apply such a method to make informed decisions about our built environment? The integration of the proposed model into a functional simulation workflow is demonstrated using an architectural case study but first the non-visual spectral effectiveness of light will be evaluated under varying sky conditions to analyze the model output sensitivity to input accuracy. The model and its application to the built environment will then be investigated using multiple view directions and by considering occupant behavior and scheduling to make an immersive prediction within a space. This novel computational approach can be seen as a first step towards human-centric lighting application, simulating an occupant's light consumption to evaluate non-visual health potential that can support decision-making in the built environment.LIPI
Ocular measures of sleepiness are increased in night shift workers undergoing a simulated night shift near the peak time of the 6-sulfatoxymelatonin rhythm
No full textStudy Objectives: The study examined the relationship between the circadian rhythm of 6-sulphatoxymelatonin (aMT6s) and ocular measures of sleepiness and neurobehavioral performance in shift workers undergoing a simulated night shift. Methods: Twenty-two shift workers (mean age 33.4, SD 11.8 years) were tested at approximately the beginning (20:00) and the end (05:55) of a simulated night shift in the laboratory. At the time point corresponding to the end of the simulated shift, 14 participants were classified as being within range of 6-sulphatoxymelatonin (aMT6s) acrophase— defined as 3 hours before or after aMT6s peak—and 8 were classified as outside aMT6s acrophase range. Participants completed the Karolinska Sleepiness Scale (KSS) and the auditory psychomotor vigilance task (aPVT). Waking electroencephalography (EEG) was recorded and infrared reflectance oculography was used to collect ocular measures of sleepiness: positive and negative amplitude/velocity ratio (PosAVR, NegAVR), mean blink total duration (BTD), the percentage of eye closure (%TEC), and a composite score of sleepiness levels (Johns Drowsiness Scale; JDS). Results: Participants who were tested within aMT6s acrophase range displayed higher levels of sleepiness on ocular measures (%TEC, BTD, PosAVR, JDS), objective sleepiness (EEG delta power frequency band), subjective ratings of sleepiness, and neurobehavioral performance, compared to those who were outside aMT6s acrophase range. Conclusions: The study demonstrated that objective ocular measures of sleepiness are sensitive to circadian rhythm misalignment in shift workers. Citation: Ftouni S, Sletten TL, Nicholas CL, Kennaway DJ, Lockley SW, Rajaratnam SM. Ocular measures of sleepiness are increased in night shift workers undergoing a simulated night shift near the peak time of the 6-sulfatoxymelatonin rhythm. J Clin Sleep Med 2015;11(10):1131–1141.Suzanne Ftouni, Tracey L. Sletten, Christian L. Nicholas, David J. Kennaway, Steven W. Lockley, Shantha M.W. Rajaratna
Mit Rewolucji Amerykańskiej a heroiczny wizerunek Tadeusza Kościuszki w amerykańskiej prasie w okresie Wczesnej Republiki
No full textThe article offers an analysis of the representations of Tadeusz Kościuszko in early American newspapers (1776-1820). The study shows that the American press presented Kościuszko as a heroic figure, significant in the making of America as a nation through his participation in the War of Independence. Kościuszko was not initially recognized as an important military leader of the Revolution, but he was re-discovered as an American hero after he had distinguished himself as the leader of the 1794 uprising in Poland. The mythologization of Kościuszko consisted in interpreting his life as a struggle for liberty, equality, and republicanism, the values which laid at the foundation of America as a nation.Artykuł stanowi analizę wizerunku Tadeusza Kościuszki we wczesnej prasie amerykańskiej (1776-1820). Wyniki badań wskazują, że prasa amerykańska przedstawiała Kościuszkę jako bohatera, postać ważną dla procesu tworzenia się (powstawania) Ameryki poprzez jego udział w Rewolucji Amerykańskiej. Początkowo Kościuszko nie był uznawany za wojskowego przywódcę Rewolucji, ale został okrzyknięty bohaterem amerykańskim po tym jak wsławił się jako przywódca powstania z 1794 roku w Polsce. Mitologizacja Kościuszki polegała na przedstawianiu jego życia jako walki o wolność, równość i republikanizm, wartości które leżały u podwalin amerykańskiego narodu.Work on this article was supported by the grant from the National Science Centre Poland (NCN) no. 2015/19/B/HS/01941. The author wishes to express gratitude to Prof. Tim Lockley and the Department of History, University of Warwick, UK for assistance in carrying out this research.Uniwersytet Marii Curie-Skłodowskiej w LublinieEarly American Newspapers, Series 1, 1690-1876, Readex America’s Historical Newspapers [Online]. Available at:http://0-infoweb.newsbank.com.pugwash.lib.warwick.ac.uk//Blakemore, Steven, Literature, Intertextuality, and the American Revolution: from Common Sense to “Rip Van Winkle”, Lanham 2014.Campbell, Joseph, The Hero with a Thousand Faces, Princeton 1949.Cavender, Gray, and Sarah Prior, Constructing the Military Hero, “International Journal of Criminology and Sociology”, vol. 2 (2013).Clark, Charles E., The Public Prints: The Newspaper in Anglo-American Culture, 1665-1740, New York 1994.Copeland, David A., Colonial American Newspapers: Character and Content, Newark 1997.Dierks, Konstantin, In My Power : Letter Writing and Communications in Early America, Philadelphia 2011.Habermas Jürgen, The Structural Transformation of the Public Sphere: An Inquiry into a Category of Bourgeois Society, Cambridge 1989.Haiman, Miecislaus, Kosciuszko in the American Revolution, New York 1975.Humphrey, Carol Sue, The Press of the Young Republic, 1783-1833, Westport 1996.Kajencki, Francis C., Thaddeus Kosciuszko: Military Engineer of the American Revolution, El Paso 1998.Klapp, Orrin, Heroes, Villains and Fools as Agents of Social Control, “American Sociological Review” 19(1954), http://dx.doi.org/10.2307/2088173.Kozłowski, W.M., Kościuszko w West-Point, „Przegląd Historyczny”, vol. 10 (1910).Leder, Lawrence H., The Role of Newspapers in Early America: “In Defense of Their Own Liberty, “Huntington Library Quarterly”, vol. 30 (1966).Linenthal, Edward Tabor, Changing Images of the Warrior Hero in America: A History of Popular Symbolism, New York 1982.Mugridge, Ian, Myth-Making and History, “The International History Review”, vol. 5 (1983).Micińska Magdalena, The Myth of Tadeusz Kościuszko in the Polish Mind (1794-1997), “European Review of History - Revue européenne d’Histoire”, vol. 5 (1998), 191-196.Nash, Gary and Graham Russell Hodges, Friends of Liberty: A Tale of Three Patriots, Two Revolutions, and the Betrayal that Divided a Nation: Thomas Jefferson, Thaddeus Kosciuszko, and Agrippa Hull, New York 2008.Newman, Simon, Parades and the Politics of the Street: Festive Culture in the Early American Republic, Philadelphia 1997.Pula, James S., Thaddeus Kościuszko: The Purest Son of Liberty, New York 1999.Ramsey, David, History of the American Revolution, 2 vols, Philadelphia 1789.Shields David S., Civil Tongues and Polite Letters in British America, Williamsburg 1997.Schlesinger Arthur M., Prelude to Independence: The Newspaper War on Britain, 1764-1776, New York 1958.Slotkin, Richard, Regeneration Through Violence: The Mythology of the American Frontier, 1600-1860, Middletown 1973.Storozynski Alex, The Peasant Prince: Thaddeus Kosciuszko and the Age of Revolution, New York 2010.Torsella, Joseph M., American National Identity, 1750-1790: Samples from the Popular Press, “The Pennsylvania Magazine of History and Biography”, vol. 112 (1988).Thompson Peter, Rum Punch and Revolution: Taverngoing and Public Life in Eighteenth-Century Philadelphia, Philadelphia 1998.Tyler, Moses C., The Literary History of the American Revolution: 1763–1863, New York 1957.Zapatka, Francis E. “Kościuszko in Early American Literature”, Polish American Studies, vol. 47 (1990).15536
Randomised controlled trial of the efficacy of a blue-enriched light intervention to improve alertness and performance in night shift workers
No full textObjectives: Night workers often experience high levels of sleepiness due to misalignment of the sleep-wake cycle from the circadian pacemaker, in addition to acute and chronic sleep loss. Exposure to light, in particular short wavelength light, can improve alertness and neurobehavioural performance. This randomised controlled trial examined the efficacy of blue-enriched polychromatic light to improve alertness and neurobehavioural performance in night workers. Design: Participants were 71 night shift workers (42 males; 32.8±10.5 years) who worked at least 6 hours between 22:00 and 08:00 hours. Sleep-wake logs and wrist actigraphy were collected for 1–3 weeks, followed by 48-hour urine collection to measure the circadian 6-sulphatoxymelatonin (aMT6s) rhythm. On the night following at least two consecutive night shifts, workers attended a simulated night shift in the laboratory which included subjective and objective assessments of sleepiness and performance. Workers were randomly assigned for exposure to one of two treatment conditions from 23:00 hours to 07:00 hours: blue-enriched white light (17 000 K, 89 lux; n=36) or standard white light (4000 K, 84 lux; n=35). Results: Subjective and objective sleepiness increased during the night shift in both light conditions (p<0.05, ηp 2=0.06–0.31), but no significant effects of light condition were observed. The 17 000 K light, however, did improve subjective sleepiness relative to the 4000 K condition when light exposure coincided with the time of the aMT6s peak (p<0.05, d=0.41–0.60). Conclusion: This study suggests that, while blue-enriched light has potential to improve subjective sleepiness in night shift workers, further research is needed in the selection of light properties to maximise the benefits. Trial registration: number The Australian New Zealand Clinical Trials Registry ACTRN12610000097044 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=320845&isReview=true).Tracey L Sletten, Suzanne Ftouni, Christian L Nicholas, Michelle Magee, Ronald R Grunstein, Sally Ferguson, David J Kennaway, Darren O, Brien, Steven W Lockley, Shantha M W Rajaratna
The spectral sensitivity of human circadian phase resetting and melatonin suppression to light changes dynamically with light duration
No full textData supporting "St Hilaire MA, Amundadottir ML, Rahman SA, Rajaratnam SMW, Ruger M, Brainard GC, Czeisler CA, Andersen M, Gooley JJ, Lockley SW. The spectral sensitivity of human circadian phase resetting and melatonin suppression to light changes dynamically with light duration. Under revie
Timed Melatonin Treatment for Delayed Sleep Phase Syndrome: The Importance of Knowing Circadian Phase
No full textOverview of the Circadian Timekeeping System and Diagnostic Tools for Circadian Rhythm Sleep Disorders
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