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Author Wilson IV, J.; Reid, K.J.; Braun, R.I.; Abbott, S.M.; Zee, P.C.
Title Habitual Light Exposure Relative to Circadian Timing in Delayed Sleep-Wake Phase Disorder Type Journal Article
Year 2018 Publication Sleep Abbreviated Journal
Volume in press Issue Pages
Keywords Human Health
Abstract Study Objectives

To compare melatonin timing, a well validated marker for endogenous circadian phase, and habitual light exposure patterns in adults with delayed sleep-wake phase disorder (DSWPD) and intermediate chronotype controls.

Methods

12 individuals with DSWPD (5 females, mean age 31.1) and 12 age matched controls (6 females, mean age 33.6) underwent a minimum of seven days of light and activity monitoring followed by an inpatient hospital stay, where blood was taken to assess melatonin timing (calculated as dim light melatonin onset – DLMO). Habitual light exposure patterns were then compared to a human phase response curve (PRC) to light.

Results

Relative to clock time, individuals with DSWPD had a later light exposure pattern compared to controls, but their light exposure pattern was earlier relative to DLMO. According to the human phase response curve (PRC) to light, individuals with DSWPD had less daily advancing light exposure compared to controls. The primary difference was seen in the late portion of the advancing window, in which individuals with DSWPD were exposed to fewer pulses of light of equivalent duration and intensity compared to controls.

Conclusions

Diminished advancing light exposure may play a role in the development and perpetuation of delayed sleep-wake timing in individuals with DSWPD. Enhancing light exposure during the later portion of the advancing window represents an innovative and complementary strategy that has the potential to improve the effectiveness of bright light therapy in DSWPD.
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 0161-8105 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (up) GFZ @ kyba @ Serial 1990
Permanent link to this record
 

 
Author Suh, Y.-W.; Na, K.-H.; Ahn, S.-E.; Oh, J.
Title Effect of Ambient Light Exposure on Ocular Fatigue during Sleep Type Journal Article
Year 2018 Publication Journal of Korean Medical Science Abbreviated Journal J Korean Med Sci
Volume 33 Issue 38 Pages
Keywords Human Health
Abstract Background

To investigate the influence of nocturnal ambient light on visual function and ocular fatigue.

Methods

Sixty healthy subjects (30 males and 30 females) aged 19 through 29 years with no history of ocular disease were recruited. All subjects spent 3 consecutive nights in the sleep laboratory. During the first and second nights, the subjects were not exposed to light during sleep, but during the third night, they were exposed to ambient light, measuring 5 or 10 lux at the eye level, which was randomly allocated with 30 subjects each. The visual function and ocular fatigue were assessed at 7 a.m. on the 3rd and 4th mornings, using best-corrected visual acuity, refractive error, conjunctival hyperemia, tear break-up time, maximal blinking interval, ocular surface temperature, and subjective symptoms reported on a questionnaire.

Results

Three male and three female subjects failed to complete the study (4 in the 5 lux; 2 from the 10 lux). For the entire 54 subjects, tear break-up time and maximal blinking interval decreased (P = 0.015; 0.010, respectively), and nasal and temporal conjunctival hyperemia increased significantly after sleep under any ambient light (P < 0.001; 0.021, respectively). Eye tiredness and soreness also increased (P = 0.004; 0.024, respectively). After sleep under 5 lux light, only nasal conjunctival hyperemia increased significantly (P = 0.008). After sleep under 10 lux light, nasal and temporal conjunctival hyperemia, eye tiredness, soreness, difficulty in focusing, and ocular discomfort increased significantly (P < 0.05).

Conclusion

Nocturnal ambient light exposure increases ocular fatigue. Avoiding ambient light during sleep could be recommended to prevent ocular fatigue.
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 1011-8934 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (up) GFZ @ kyba @ Serial 1991
Permanent link to this record
 

 
Author Taylor, G.; Davies, W.J.
Title The Control Of Leaf Growth Of Betula And Acer By Photoenvironment Type Journal Article
Year 1985 Publication New Phytologist Abbreviated Journal New Phytol
Volume 101 Issue 2 Pages 259-268
Keywords Plants
Abstract Leaf extension of one‐year‐old seedlings of silver birch (Betula pendula Roth.) and sycamore (Acer pseudoplatanus L.), was measured using linear variable transducers (LVDTs) interfaced to a microcomputer. Birch and sycamore seedlings exhibited contrasting patterns of leaf extension during a diurnal cycle with a 16 h photoperiod. Birch leaves grew more rapidly when illuminated; growth during the photoperiod was approximately doubled when compared with growth in the dark. Mean relative growth rates ±SE at ‘lights‐on + 3 h’ and ‘lights‐off + 5 h’ were 0.0136 ± 0.0016 and 0.0066 ± 0.0005 h−1 respectively. In direct contrast, growth of sycamore leaves was increased when leaves were darkened; mean relative growth rates + SE at ‘lights‐on+3 h’ and ‘lights‐off + 5 h’ were 0.0056 ± 0.0005 and 0.0094 ± 0.0008 h‐1 respectively.

When leaves of birch and sycamore were darkened, increased leaf turgor was measured in both species, but only in sycamore was this higher night‐time turgor associated with a higher rate of leaf growth.

Cell wall extensibility (WEX), an indication of the ability of cell walls to loosen and extend irreversibly, and cell surface pH were assessed in darkened and illuminated leaves of both species. An increase in WEX was measured when birch leaves were illuminated (P≤ 0.001) and this was accompanied by a decline in cell surface pH (P≤ 0.001). However, when leaves of sycamore were illuminated, WEX declined (P≤ 005) and cell surface pH increased (P≤ 0.001).

The ability of these species to survive beneath a woodland canopy is discussed in relation to the cellular factors controlling their leaf growth.
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 0028-646X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (up) GFZ @ kyba @ Serial 1992
Permanent link to this record
 

 
Author Zhao, N.; Cao, G.; Zhang, W.; Samson, E.L.
Title Tweets or nighttime lights: Comparison for preeminence in estimating socioeconomic factors Type Journal Article
Year 2018 Publication ISPRS Journal of Photogrammetry and Remote Sensing Abbreviated Journal ISPRS Journal of Photogrammetry and Remote Sensing
Volume 146 Issue Pages 1-10
Keywords Remote Sensing
Abstract Nighttime lights (NTL) imagery is one of the most commonly used tools to quantitatively study socioeconomic systems over large areas. In this study we aim to use location-based social media big data to challenge the primacy of NTL imagery on estimating socioeconomic factors. Geo-tagged tweets posted in the contiguous United States in 2013 were retrieved to produce a tweet image with the same spatial resolution of the NTL imagery (i.e., 0.00833° × 0.00833°). Sum tweet (the total number of tweets) and sum light (summed DN value of the NTL image) of each state or county were obtained from the tweets and the NTL images, respectively, to estimate three important socioeconomic factors: personal income, electric power consumption, and fossil fuel carbon dioxide emissions. Results show that sum tweet is a better measure of personal income and electric power consumption while carbon dioxide emissions can be more accurately estimated by sum light. We further exploited that African-Americans adults are more likely than White seniors to post geotagged tweets in the US, yet did not find any significant correlations between proportions of the subpopulations and the estimation accuracy of the socioeconomic factors. Existence of saturated pixels and blooming effects and failure to remove gas flaring reduce quality of NTL imagery in estimating socioeconomic factors, however, such problems are nonexistent in the tweet images. This study reveals that the number of geo-tagged tweets has great potential to be deemed as a substitute of brightness of NTL to assess socioeconomic factors over large geographic areas.
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 0924-2716 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (up) GFZ @ kyba @ Serial 1994
Permanent link to this record
 

 
Author Ma, T.
Title Multi-Level Relationships between Satellite-Derived Nighttime Lighting Signals and Social Media–Derived Human Population Dynamics Type Journal Article
Year 2018 Publication Remote Sensing Abbreviated Journal Remote Sensing
Volume 10 Issue 7 Pages 1128
Keywords Remote Sensing
Abstract Satellite-based measurements of the artificial nighttime light brightness (NTL) have been extensively used for studying urbanization and socioeconomic dynamics in a temporally consistent and spatially explicit manner. The increasing availability of geo-located big data detailing human population dynamics provides a good opportunity to explore the association between anthropogenic nocturnal luminosity and corresponding human activities, especially at fine time/space scales. In this study, we used Visible Infrared Imaging Radiometer Suite (VIIRS) day/night band (DNB)–derived nighttime light images and the gridded number of location requests (NLR) from China’s largest social media platform to investigate the quantitative relationship between nighttime light radiances and human population dynamics across China at four levels: the provincial, city, county, and pixel levels. Our results show that the linear relationship between the NTL and NLR might vary with the observation level and magnitude. The dispersion between the two variables likely increases with the observation scale, especially at the pixel level. The effect of spatial autocorrelation and other socioeconomic factors on the relationship should be taken into account for nighttime light-based measurements of human activities. Furthermore, the bivariate relationship between the NTL and NLR was employed to generate a partition of human settlements based on the combined features of nighttime lights and human population dynamics. Cross-regional comparisons of the partitioned results indicate a diverse co-distribution of the NTL and NLR across various types of human settlements, which could be related to the city size/form and urbanization level. Our findings may provide new insights into the multi-level responses of nighttime light signals to human activity and the potential application of nighttime light data in association with geo-located big data for investigating the spatial patterns of human settlement.
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 2072-4292 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (up) GFZ @ kyba @ Serial 1996
Permanent link to this record