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Author Stone, J.E.; Phillips, A.J.K.; Ftouni, S.; Magee, M.; Howard, M.; Lockley, S.W.; Sletten, T.L.; Anderson, C.; Rajaratnam, S.M.W.; Postnova, S.
Title Generalizability of A Neural Network Model for Circadian Phase Prediction in Real-World Conditions Type Journal Article
Year 2019 Publication Scientific Reports Abbreviated Journal Sci Rep
Volume 9 Issue 1 Pages (down) 11001
Keywords Human Health; Instrumentation
Abstract A neural network model was previously developed to predict melatonin rhythms accurately from blue light and skin temperature recordings in individuals on a fixed sleep schedule. This study aimed to test the generalizability of the model to other sleep schedules, including rotating shift work. Ambulatory wrist blue light irradiance and skin temperature data were collected in 16 healthy individuals on fixed and habitual sleep schedules, and 28 rotating shift workers. Artificial neural network models were trained to predict the circadian rhythm of (i) salivary melatonin on a fixed sleep schedule; (ii) urinary aMT6s on both fixed and habitual sleep schedules, including shift workers on a diurnal schedule; and (iii) urinary aMT6s in rotating shift workers on a night shift schedule. To determine predicted circadian phase, center of gravity of the fitted bimodal skewed baseline cosine curve was used for melatonin, and acrophase of the cosine curve for aMT6s. On a fixed sleep schedule, the model predicted melatonin phase to within +/- 1 hour in 67% and +/- 1.5 hours in 100% of participants, with mean absolute error of 41 +/- 32 minutes. On diurnal schedules, including shift workers, the model predicted aMT6s acrophase to within +/- 1 hour in 66% and +/- 2 hours in 87% of participants, with mean absolute error of 63 +/- 67 minutes. On night shift schedules, the model predicted aMT6s acrophase to within +/- 1 hour in 42% and +/- 2 hours in 53% of participants, with mean absolute error of 143 +/- 155 minutes. Prediction accuracy was similar when using either 1 (wrist) or 11 skin temperature sensor inputs. These findings demonstrate that the model can predict circadian timing to within +/- 2 hours for the vast majority of individuals on diurnal schedules, using blue light and a single temperature sensor. However, this approach did not generalize to night shift conditions.
Address School of Physics, University of Sydney, Sydney, New South Wales, Australia
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 2045-2322 ISBN Medium
Area Expedition Conference
Notes PMID:31358781; PMCID:PMC6662750 Approved no
Call Number GFZ @ kyba @ Serial 2667
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Author den Outer, P.; Lolkema, D.; Haaima, M.; van der Hoff, R.; Spoelstra, H.; Schmidt, W.
Title Intercomparisons of nine sky brightness detectors Type Journal Article
Year 2011 Publication Sensors (Basel, Switzerland) Abbreviated Journal Sensors (Basel)
Volume 11 Issue 10 Pages (down) 9603-9612
Keywords Calibration; Darkness; *Extraterrestrial Environment; Humans; Light; Luminescent Measurements; Netherlands; *Optical Phenomena; Optics and Photonics/*instrumentation/*methods; Sky Quality Meter; artificial lighting; intercalibration; intercomparison; light pollution; night sky brightness
Abstract Nine Sky Quality Meters (SQMs) have been intercompared during a night time measurement campaign held in the Netherlands in April 2011. Since then the nine SQMs have been distributed across The Netherlands and form the Dutch network for monitoring night sky brightness. The goal of the intercomparison was to infer mutual calibration factors and obtain insight into the variability of the SQMs under different meteorological situations. An ensemble average is built from the individual measurements and used as a reference to infer the mutual calibration factors. Data required additional synchronization prior to the calibration determination, because the effect of moving clouds combined with small misalignments emerges as time jitter in the measurements. Initial scatter of the individual instruments lies between +/-14%. Individual night time sums range from -16% to +20%. Intercalibration reduces this to 0.5%, and -7% to +9%, respectively. During the campaign the smallest luminance measured was 0.657 +/- 0.003 mcd/m(2) on 12 April, and the largest value was 5.94 +/- 0.03 mcd/m(2) on 2 April. During both occurrences interfering circumstances like snow cover or moonlight were absent.
Address National Institute for Public Health and the Environment, A. van Leeuwenhoeklaan 9, 3720 BA Bilthoven, The Netherlands. peter.den.outer@rivm.nl
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 1424-8220 ISBN Medium
Area Expedition Conference
Notes PMID:22163715; PMCID:PMC3231263 Approved no
Call Number IDA @ john @ Serial 196
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Author den Outer, P.; Lolkema, D.; Haaima, M.; van der Hoff, R.; Spoelstra, H.; Schmidt, W.
Title Stability of the Nine Sky Quality Meters in the Dutch Night Sky Brightness Monitoring Network Type Journal Article
Year 2015 Publication Sensors Abbreviated Journal Sensors
Volume 15 Issue 4 Pages (down) 9466-9480
Keywords Instrumentation
Abstract
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 1424-8220 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 1157
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Author Miller, S.; Straka, W.; Mills, S.; Elvidge, C.; Lee, T.; Solbrig, J.; Walther, A.; Heidinger, A.; Weiss, S.
Title Illuminating the Capabilities of the Suomi National Polar-Orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band Type Journal Article
Year 2013 Publication Remote Sensing Abbreviated Journal Remote Sensing
Volume 5 Issue 12 Pages (down) 6717-6766
Keywords Instrumentation; satellite imagery; nighttime visible/near-infrared; moonlight
Abstract Daytime measurements of reflected sunlight in the visible spectrum have been a staple of Earth-viewing radiometers since the advent of the environmental satellite platform. At night, these same optical-spectrum sensors have traditionally been limited to thermal infrared emission, which contains relatively poor information content for many important weather and climate parameters. These deficiencies have limited our ability to characterize the full diurnal behavior and processes of parameters relevant to improved monitoring, understanding and modeling of weather and climate processes. Visible-spectrum light information does exist during the nighttime hours, originating from a wide variety of sources, but its detection requires specialized technology. Such measurements have existed, in a limited way, on USA Department of Defense satellites, but the Suomi National Polar-orbiting Partnership (NPP) satellite, which carries a new Day/Night Band (DNB) radiometer, offers the first quantitative measurements of nocturnal visible and near-infrared light. Here, we demonstrate the expanded potential for nocturnal low-light visible applications enabled by the DNB. Via a combination of terrestrial and extraterrestrial light sources, such observations are always available—expanding many current existing applications while enabling entirely new capabilities. These novel low-light measurements open doors to a wealth of new interdisciplinary research topics while lighting a pathway toward the optimized design of follow-on satellite based low light visible sensors.
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 LoNNe @ christopher.kyba @ Serial 468
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Author Voigt, L.P.; Reynolds, K.; Mehryar, M.; Chan, W.S.; Kostelecky, N.; Pastores, S.M.; Halpern, N.A.
Title Monitoring sound and light continuously in an intensive care unit patient room: A pilot study Type Journal Article
Year 2016 Publication Journal of Critical Care Abbreviated Journal Journal of Critical Care
Volume 38 Issue 21 Pages (down) 5952-5961
Keywords Instrumentation; Human Health
Abstract Purpose

To determine the feasibility of continuous recording of sound and light in the intensive care unit (ICU).

Materials and Methods

Four one-hour baseline scenarios in an empty ICU patient room by day and night (doors open or closed and maximal or minimal lighting) and two daytime scenarios simulating a stable and unstable patient (quiet or loud devices and staff) were conducted. Sound and light levels were continuously recorded using a commercially available multisensor monitor and transmitted via the hospital's network to a cloud-based data storage and management system.

Results

The empty ICU room was loud with similar mean sound levels for the day and night simulations of 45–46 dBA. Mean levels for maximal lighting during day and night ranged from 1306–1812 lux and mean levels for minimum lighting were 1–3 lux. The mean sound levels for the stable and unstable patient simulations were 61 and 81 dBA, respectively. The mean light levels were 349 lux for the stable patient and 1947 lux for the unstable patient.

Conclusions

Combined sound and light can be continuously and easily monitored in the ICU setting. Incorporating sound and light monitors in ICU rooms may promote an enhanced patient and staff centered healing environment.
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 0883-9441 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1614
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