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Author Aubé, M.; Roby, J.; Kocifaj, M.
Title Evaluating potential spectral impacts of various artificial lights on melatonin suppression, photosynthesis, and star visibility Type Journal Article
Year 2013 Publication PloS one Abbreviated Journal PLoS One
Volume 8 Issue 7 Pages e67798
Keywords Humans; *Light; Lighting/methods; Melatonin/*metabolism; Photosynthesis/*radiation effects; Plant Development/radiation effects; blue light; circadian disruption
Abstract Artificial light at night can be harmful to the environment, and interferes with fauna and flora, star visibility, and human health. To estimate the relative impact of a lighting device, its radiant power, angular photometry and detailed spectral power distribution have to be considered. In this paper we focus on the spectral power distribution. While specific spectral characteristics can be considered harmful during the night, they can be considered advantageous during the day. As an example, while blue-rich Metal Halide lamps can be problematic for human health, star visibility and vegetation photosynthesis during the night, they can be highly appropriate during the day for plant growth and light therapy. In this paper we propose three new indices to characterize lamp spectra. These indices have been designed to allow a quick estimation of the potential impact of a lamp spectrum on melatonin suppression, photosynthesis, and star visibility. We used these new indices to compare various lighting technologies objectively. We also considered the transformation of such indices according to the propagation of light into the atmosphere as a function of distance to the observer. Among other results, we found that low pressure sodium, phosphor-converted amber light emitting diodes (LED) and LED 2700 K lamps filtered with the new Ledtech's Equilib filter showed a lower or equivalent potential impact on melatonin suppression and star visibility in comparison to high pressure sodium lamps. Low pressure sodium, LED 5000 K-filtered and LED 2700 K-filtered lamps had a lower impact on photosynthesis than did high pressure sodium lamps. Finally, we propose these indices as new standards for the lighting industry to be used in characterizing their lighting technologies. We hope that their use will favor the design of new environmentally and health-friendly lighting technologies.
Address Departement de physique, Cegep de Sherbrooke, Sherbrooke, Quebec, Canada. martin.aube@cegepsherbrooke.qc.ca
Corporate Author Thesis
Publisher Place of Publication (up) 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:23861808; PMCID:PMC3702543 Approved no
Call Number IDA @ john @ Serial 282
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Author Jou, J.-H.; Hsieh, C.-Y.; Tseng, J.-R.; Peng, S.-H.; Jou, Y.-C.; Hong, J.H.; Shen, S.-M.; Tang, M.-C.; Chen, P.-C.; Lin, C.-H.
Title Candle Light-Style Organic Light-Emitting Diodes Type Journal Article
Year 2013 Publication Advanced Functional Materials Abbreviated Journal Adv. Funct. Mater.
Volume 23 Issue 21 Pages 2750-2757
Keywords organic light emitting diodes; candle light; firelight; OLED; CRI; color rendition
Abstract In response to the call for a physiologically-friendly light at night that shows low color temperature, a candle light-style organic light emitting diode (OLED) is developed with a color temperature as low as 1900 K, a color rendering index (CRI) as high as 93, and an efficacy at least two times that of incandescent bulbs. In addition, the device has a 80% resemblance in luminance spectrum to that of a candle. Most importantly, the sensationally warm candle light-style emission is driven by electricity in lieu of the energy-wasting and greenhouse gas emitting hydrocarbon-burning candles invented 5000 years ago. This candle light-style OLED may serve as a safe measure for illumination at night. Moreover, it has a high color rendering index with a decent efficiency.
Address
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616301X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 284
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Author Bedrosian, T.A. (ed)
Title Circadian Disruption by Light at Night: Implications for Mood Type Book Whole
Year 2013 Publication Abbreviated Journal
Volume Issue Pages
Keywords circadian disruption; sleep; light at night; melanopsin; mood; mental health; Mood Disorders; epigenetics; red light
Abstract Life on Earth has adapted to a consistent 24-h solar cycle. Circadian rhythms in physiology and behavior remain synchronized to the environment using light as the most potent entraining cue. During the past century, however, the widespread adoption of electric light has led to `round-the-clock’ societies. Instead of aligning with the environment, individuals follow artificial and often erratic light cycles created by social and work schedules. In particular, exposure to artificial light at night (LAN), termed “light pollution”, has become pervasive over the past 100 years. Virtually every individual living in the U.S. and Europe experiences this aberrant light exposure, and moreover about 20% of the population performs shift work. LAN may disrupt physiological timekeeping, leading to dysregulation of internal processes and misalignment between behavior and the environment. Recent evidence suggests that individuals exposed to excessive LAN, such as night shift workers, have increased risk for depressive disorders, but the biological mechanism remains unspecified. In mammals, intrinsically photosensitive retinal ganglion cells (ipRGCs) project light information to (1) the suprachiasmatic nucleus (SCN) in the hypothalamus, regulating circadian rhythms, and (2) to limbic regions, putatively regulating mood. Thus, LAN has the potential to affect both circadian timekeeping and mood. In this dissertation, I present evidence from rodent studies supporting the novel hypothesis that night-time exposure to light disrupts circadian organization and contributes to depressed mood. First, I consider the physiological and behavioral consequences associated with unnatural exposure to LAN. The effects of LAN on circadian output are considered in terms of locomotor activity, the diurnal cortisol rhythm, and diurnal clock protein expression in the brain in Chapter 2. The influence of LAN on behavior and brain plasticity is discussed, with particular focus on depressive-like behavior (Chapter 3) and effects of SSRI treatment (Chapter 4). Effects of LAN on structural plasticity and gene expression in the brain are described, with emphasis on potential correlates of the depressive-like behavior observed under LAN in Chapter 5. Given the prevalence of LAN exposure and its importance, strategies for reversing the effects are offered. Specifically, eliminating LAN quickly reverses behavioral and physiological effects of exposure as described in Chapter 5. In Chapter 6 I report that administration of a pharmacological cytokine inhibitor prevents depressive-like behaviors in LAN, implicating brain inflammation in the behavioral effect. Finally, I demonstrate in Chapter 7 that exposure to red wavelength LAN reduces the effects on brain and behavior, suggesting that LAN acts through specific retinal pathways involving melanopsin. Taken together, these studies demonstrate the consequences of LAN, but also outline potential avenues for prevention or intervention.
Address Department of Neuroscience and The Institute for Behavioral Medicine Research The Ohio State University
Corporate Author Thesis Ph.D. thesis
Publisher Place of Publication (up) Editor Bedrosian, T.A.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 323
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Author Fuller, G. (ed)
Title The Night Shift: Lighting and Nocturnal Strepsirrhine Care in Zoos Type Book Whole
Year 2013 Publication Abbreviated Journal
Volume Issue Pages
Keywords zoos; light at night; circadian disruption; strepsirrhines; primates; lorises; pottos; lighting design
Abstract Over billions of years of evolution, light from the sun, moon, and stars has provided

organisms with reliable information about the passage of time. Photic cues entrain

the circadian system, allowing animals to perform behaviors critical for survival and

reproduction at optimal times. Modern artificial lighting has drastically altered

environmental light cues. Evidence is accumulating that exposure to light at night

(particularly blue wavelengths) from computer screens, urban light pollution, or as

an occupational hazard of night-shift work has major implications for human health.

Nocturnal animals are the shift workers of zoos; they are generally housed on

reversed light cycles so that daytime visitors can observe their active behaviors. As a

result, they are exposed to artificial light throughout their subjective night. The goal

of this investigation was to examine critically the care of nocturnal strepsirrhine

primates in North American zoos, focusing on lorises (Loris and Nycticebus spp.) and pottos (Perodicticus potto). The general hypothesis was that exhibit lighting design affects activity patterns and circadian physiology in nocturnal strepsirrhines. The

first specific aim was to assess the status of these populations. A multi-institutional husbandry survey revealed little consensus among zoos in lighting design, with both red and blue light commonly used for nocturnal illumination. A review of medical records also revealed high rates of neonate mortality. The second aim was to

develop methods for measuring the effects of exhibit lighting on behavior and

health. The use of actigraphy for automated activity monitoring was explored.

Methods were also developed for measuring salivary melatonin and cortisol as

indicators of circadian disruption. Finally, a multi-institutional study was conducted

comparing behavioral and endocrine responses to red and blue dark phase lighting.

These results showed greater activity levels in strepsirrhines housed under red light than blue. Salivary melatonin concentrations in pottos suggested that blue light

suppressed nocturnal melatonin production at higher intensities, but evidence for

circadian disruption was equivocal. These results add to the growing body of

evidence on the detrimental effects of blue light at night and are a step towards

empirical recommendations for nocturnal lighting design in zoos.
Address Department of Biology, Case Western Reserve University
Corporate Author Thesis Ph.D. thesis
Publisher Place of Publication (up) Editor Fuller, G.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 327
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Author Gil-de-Castro, A.; Moreno-Munoz, A.; Larsson, A.; de la Rosa, J.; Bollen, M.
Title LED street lighting: A power quality comparison among street light technologies Type Journal Article
Year 2013 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology
Volume 45 Issue 6 Pages 710-728
Keywords LED; LED lighting; high-pressure sodium; HPS; outdoor lighting; lighting technology
Abstract High-pressure sodium lamps are currently the main lamps used in public lighting. However, the possibility of using high-power light emitting diode (LEDs) for street lighting is growing continuously due to their greater energy efficiency, robustness, long life and light control. The aim of this paper is to study the power quality of high-power lighting networks based on LED and high-pressure sodium lamps. Both electromagnetic and dimmable electronic ballasts, which can dim the lamp output smoothly and uniformly, have been used connected to high-pressure sodium lamps. High-pressure sodium lamps connected to electronic equipment have been tested with different arc power levels using dimming on a 230 V power supply. The study presented in this paper is completely based on measurements, including harmonic currents in the frequency range up to 150 kHz for all the technologies. The main results show a broadband spectrum in LED lamps which confirms other research in fluorescent lamps powered by high-frequency ballasts. Results also indicate a decrease in the harmonic value with increasing harmonic order, and a decrease in the harmonic value at half load (60%) compared with full load (100%). Although total harmonic distortion of the current is lower with high-pressure sodium lamps connected to electronic rather than electromagnetic ballasts, LED lamps achieved the lowest total harmonic distortion of current.
Address Department of Computer Architecture, Electronics and Electronic Technology, University of Cordoba, Cordoba, Spain
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-1535 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 333
Permanent link to this record