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Author Cajochen, C.; Frey, S.; Anders, D.; Spati, J.; Bues, M.; Pross, A.; Mager, R.; Wirz-Justice, A.; Stefani, O.
Title Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance Type Journal Article
Year 2011 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol (1985)
Volume (down) 110 Issue 5 Pages 1432-1438
Keywords Adult; Circadian Rhythm/*physiology/radiation effects; Cognition/*physiology/radiation effects; *Computer Terminals; Humans; Light; Lighting/*methods; Male; Photic Stimulation/*methods; Radiation Dosage; Semiconductors; *Task Performance and Analysis; Young Adult; blue light; sleep; circadian disruption
Abstract Many people spend an increasing amount of time in front of computer screens equipped with light-emitting diodes (LED) with a short wavelength (blue range). Thus we investigated the repercussions on melatonin (a marker of the circadian clock), alertness, and cognitive performance levels in 13 young male volunteers under controlled laboratory conditions in a balanced crossover design. A 5-h evening exposure to a white LED-backlit screen with more than twice as much 464 nm light emission {irradiance of 0,241 Watt/(steradian x m(2)) [W/(sr x m(2))], 2.1 x 10(13) photons/(cm(2) x s), in the wavelength range of 454 and 474 nm} than a white non-LED-backlit screen [irradiance of 0,099 W/(sr x m(2)), 0.7 x 10(13) photons/(cm(2) x s), in the wavelength range of 454 and 474 nm] elicited a significant suppression of the evening rise in endogenous melatonin and subjective as well as objective sleepiness, as indexed by a reduced incidence of slow eye movements and EEG low-frequency activity (1-7 Hz) in frontal brain regions. Concomitantly, sustained attention, as determined by the GO/NOGO task; working memory/attention, as assessed by “explicit timing”; and declarative memory performance in a word-learning paradigm were significantly enhanced in the LED-backlit screen compared with the non-LED condition. Screen quality and visual comfort were rated the same in both screen conditions, whereas the non-LED screen tended to be considered brighter. Our data indicate that the spectral profile of light emitted by computer screens impacts on circadian physiology, alertness, and cognitive performance levels. The challenge will be to design a computer screen with a spectral profile that can be individually programmed to add timed, essential light information to the circadian system in humans.
Address Centre for Chronobiology, Psychiatric Hospitals of the University of Basel, Basel, Switzerland. christian.cajochen@upkbs.ch
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 0161-7567 ISBN Medium
Area Expedition Conference
Notes PMID:21415172 Approved no
Call Number IDA @ john @ Serial 293
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Author Srinivasan, V.; Spence, D.W.; Pandi-Perumal, S.R.; Trakht, I.; Esquifino, A.I.; Cardinali, D.P.; Maestroni, G.J.
Title Melatonin, environmental light, and breast cancer Type Journal Article
Year 2008 Publication Breast Cancer Research and Treatment Abbreviated Journal Breast Cancer Res Treat
Volume (down) 108 Issue 3 Pages 339-350
Keywords Human Health; Breast Neoplasms/*etiology/*physiopathology; Circadian Rhythm/physiology; Female; Humans; Light; Lighting/*adverse effects; Melatonin/*physiology; Occupational Exposure/adverse effects
Abstract Although many factors have been suggested as causes for breast cancer, the increased incidence of the disease seen in women working in night shifts led to the hypothesis that the suppression of melatonin by light or melatonin deficiency plays a major role in cancer development. Studies on the 7,12-dimethylbenz[a]anthracene and N-methyl-N-nitrosourea experimental models of human breast cancer indicate that melatonin is effective in reducing cancer development. In vitro studies in MCF-7 human breast cancer cell line have shown that melatonin exerts its anticarcinogenic actions through a variety of mechanisms, and that it is most effective in estrogen receptor (ER) alpha-positive breast cancer cells. Melatonin suppresses ER gene, modulates several estrogen dependent regulatory proteins and pro-oncogenes, inhibits cell proliferation, and impairs the metastatic capacity of MCF-7 human breast cancer cells. The anticarcinogenic action on MCF-7 cells has been demonstrated at the physiological concentrations of melatonin attained at night, suggesting thereby that melatonin acts like an endogenous antiestrogen. Melatonin also decreases the formation of estrogens from androgens via aromatase inhibition. Circulating melatonin levels are abnormally low in ER-positive breast cancer patients thereby supporting the melatonin hypothesis for breast cancer in shift working women. It has been postulated that enhanced endogenous melatonin secretion is responsible for the beneficial effects of meditation as a form of psychosocial intervention that helps breast cancer patients.
Address Department of Physiology, School of Medical Sciences, University Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
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 0167-6806 ISBN Medium
Area Expedition Conference
Notes PMID:17541739 Approved no
Call Number LoNNe @ kagoburian @ Serial 815
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Author Ebbensgaard, C.L.
Title Making sense of diodes and sodium: Vision, visuality and the everyday experience of infrastructural change Type Journal Article
Year 2019 Publication Geoforum Abbreviated Journal Geoforum
Volume (down) 103 Issue Pages 95-104
Keywords Lighting; visual sensorium; United Kingdom
Abstract The recognition of vision as a powerful register for organising urban space locates lighting technologies at the heart of urban experience. Recently, scholars have established that lighting technologies shape not just what we see but how we see, drawing attention towards light as that ‘with which we see’. This article shifts attention from the role of lighting in shaping what and how people see, to how people make sense of changes to their visual sensorium—from what lighting infrastructures do to what is done with them. By following older residents living in the London Borough of Newham along routine travels on foot at night, I demonstrate how they make sense of the Council’s initiative to upgrade their 19,500 street-lamps with Light Emitting Diodes. I demonstrate how such infrastructural change exposes an uneven geographical distribution of and access to light and darkness with potentially detrimental consequences for the formation of public life after dark. Recognising how light infrastructures are reframed through everyday life, I demonstrate how LEDs do not necessarily produce their desired effects and how light clutter and light bleed might contribute to producing nocturnal atmospheres where people feel safe and confident. Broadening the understanding of how different technologies and light sources are important for the formation of inclusive nocturnal publics the article sets out a ‘politics of visibility’ that recognises the role of lighting in creating visibility for and of residents.
Address Queen Mary University of London, 329 Mile End Road, London E1 4NS, United Kingdom; c.l.ebbensgaard(at)qmul.ac.uk
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0016-7185 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2360
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Author Lockwood, G.W.; Thompson, D.T.; Floyd, R.D.
Title Sky glow and outdoor lighting trends since 1976 at the Lowell Observatory Type Journal Article
Year 1990 Publication Publications of the Astronomical Society of the Pacific Abbreviated Journal PASP
Volume (down) 102 Issue Pages 481
Keywords Skyglow; Lighting
Abstract Urban sky-glow (light pollution) trends, recorded photoelectrically in intermediate-band b (472 nm) and y (551 nm) filters at the original site of the Lowell Observatory on Mars Hill near downtown Flagstaff, Arizona, reflect not just the population growth of the surrounding city but also some ameliorating effects of lighting controls and a changing mix of outdoor lighting sources. Since 1976 the sky brightness increased in b but has been virtually constant in y. New ordinances limit lighting growth near observatories and require monochromatic low-pressure sodium luminaires for most applications.
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 0004-6280 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 3026
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Author Łopuszyńska, A.; Bartyna-Zielińska, M.; Kaźmierczak, B.; Jadwiszczak, P.; Kutyłowska, M.; Miller, U.
Title Lighting of urban green areas – the case of Grabiszyn Park in Wrocław. Searching for the balance between light and darkness through social and technical issues Type Journal Article
Year 2019 Publication E3S Web of Conferences Abbreviated Journal E3S Web Conf.
Volume (down) 100 Issue Pages 00049
Keywords Society; Lighting
Abstract Illuminating the urban green spaces could lead to conflicts of spatial, technical and social nature. This relatively new, though already global, problem is expected to grow bigger with the further increase of urban areas artificial brightness. The case of Grabiszyn Park in Wrocław is an example of how difficult it is to find a balance between big-city lights and a natural darkness. The situation is even more difficult if the light is not legally recognized as a significant source of air pollution and direct nuisance at the legal level. The aim of the paper is to recognize the broader perspective of urban greenery lighting issues, global recommendations basis and the local awareness. The authors also made an attempt to analyze and assess the project implementation, as well as to characterize the components of the quality of an urban green areas lighting.
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 2267-1242 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2603
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