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Author Leise, T.L.; Goldberg, A.; Michael, J.; Montoya, G.; Solow, S.; Molyneux, P.; Vetrivelan, R.; Harrington, M.E.
Title Recurring circadian disruption alters circadian clock sensitivity to resetting Type Journal Article
Year 2018 Publication The European Journal of Neuroscience Abbreviated Journal Eur J Neurosci
Volume in press Issue Pages
Keywords Animals
Abstract A single phase advance of the light:dark (LD) cycle can temporarily disrupt synchrony of neural circadian rhythms within the suprachiasmatic nucleus (SCN) and between the SCN and peripheral tissues. Compounding this, modern life can involve repeated disruptive light conditions. To model chronic disruption to the circadian system, we exposed male mice to more than a month of a 20 h light cycle (LD10:10), which mice typically cannot entrain to. Control animals were housed under LD12:12. We measured locomotor activity and body temperature rhythms in vivo, and rhythms of PER2::LUC bioluminescence in SCN and peripheral tissues ex vivo. Unexpectedly, we discovered strong effects of the time of dissection on circadian phase of PER2::LUC bioluminescent rhythms, which varied across tissues. White adipose tissue was strongly reset by dissection, while thymus phase appeared independent of dissection timing. Prior light exposure impacted the SCN, resulting in strong resetting of SCN phase by dissection for mice housed under LD10:10, and weak phase shifts by time of dissection in SCN from control LD12:12 mice. These findings suggest that exposure to circadian disruption may desynchronize SCN neurons, increasing network sensitivity to perturbations. We propose that tissues with a weakened circadian network, such as the SCN under disruptive light conditions, or with little to no coupling, e.g., some peripheral tissues, will show increased resetting effects. In particular, exposure to light at inconsistent circadian times on a recurring weekly basis disrupts circadian rhythms and alters sensitivity of the SCN neural pacemaker to dissection time. This article is protected by copyright. All rights reserved.
Address (down) Neuroscience Program, Smith College, Northampton, MA, 01063, USA
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 0953-816X ISBN Medium
Area Expedition Conference
Notes PMID:30269396 Approved no
Call Number GFZ @ kyba @ Serial 2036
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Author Sharma, A.; Goyal, R.
Title Long-term exposure to constant light induces dementia, oxidative stress and promotes aggregation of sub-pathological Abeta42 in Wistar rats Type Journal Article
Year 2020 Publication Pharmacology, Biochemistry, and Behavior Abbreviated Journal Pharmacol Biochem Behav
Volume in press Issue Pages 172892
Keywords Animals; Amyloid beta; Behavior, fluoxetine, rifampicin; Oxidative stress
Abstract Constant exposure to light is prevalent in modern society where light noise, shift work, and jet lag is common. Constant light exposure disrupts circadian rhythm, induces stress and thus influences memory performance. We subjected adult male Wistar rats to a two-month exposure to constant light (LL), constant dark or normal light-dark cycles. Significant cognitive impairment and oxidative stress were observed in LL rats without a significant elevation in soluble Abeta1-42 levels. Next, we examined whether long-term exposure to constant light may accelerate dementia in a sub-pathological Abeta model of rats. Normal control rats received ACSF, AD rats received 440pmol, and sub-pathological Abeta rats (Abeta(s)) received 220pmol of human Abeta42 peptide in a single unilateral ICV administration. Sub-pathological Abeta rats exposed to constant light (LL+Abeta(s)) show significant memory deficits and oxidative damage, although not significantly different from LL rats. Additionally, constant light promoted aggregation of exogenous Abeta42 in LL+Abeta(s) rats shown by the presence of congophilic plaques. Furthermore, chronic fluoxetine treatment (5mg/kg/day) rescued rats from the behavioral deficits, oxidative damage and amyloid aggregation. Whereas, rifampicin treatment (20mg/kg/day) did not reverse the behavioral deficits or oxidative stress but rescued rats from amyloid plaque formation. It was concluded that constant light for two months induces behavioral deficits, oxidative stress, and accelerates aggregation of sub-pathological concentrations of human-Abeta42 peptides in Wistar rats, which is reversed by daily fluoxetine administration.
Address (down) Neuropharmacology Laboratory, School of Pharmaceutical Sciences, Shoolini University, Solan 173 212, Himachal Pradesh, India. Electronic address: rohitgoyal@shooliniuniversity.com
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 0091-3057 ISBN Medium
Area Expedition Conference
Notes PMID:32142744 Approved no
Call Number GFZ @ kyba @ Serial 2841
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Author Jan Stenvers, D.; Scheer, F.A.J.L.; Schrauwen, P.; la Fleur, S.E.; Kalsbeek, A.
Title Circadian clocks and insulin resistance Type Journal Article
Year 2018 Publication Nature Reviews. Endocrinology Abbreviated Journal Nat Rev Endocrinol
Volume in press Issue Pages
Keywords Human Health; Review
Abstract Insulin resistance is a main determinant in the development of type 2 diabetes mellitus and a major cause of morbidity and mortality. The circadian timing system consists of a central brain clock in the hypothalamic suprachiasmatic nucleus and various peripheral tissue clocks. The circadian timing system is responsible for the coordination of many daily processes, including the daily rhythm in human glucose metabolism. The central clock regulates food intake, energy expenditure and whole-body insulin sensitivity, and these actions are further fine-tuned by local peripheral clocks. For instance, the peripheral clock in the gut regulates glucose absorption, peripheral clocks in muscle, adipose tissue and liver regulate local insulin sensitivity, and the peripheral clock in the pancreas regulates insulin secretion. Misalignment between different components of the circadian timing system and daily rhythms of sleep-wake behaviour or food intake as a result of genetic, environmental or behavioural factors might be an important contributor to the development of insulin resistance. Specifically, clock gene mutations, exposure to artificial light-dark cycles, disturbed sleep, shift work and social jet lag are factors that might contribute to circadian disruption. Here, we review the physiological links between circadian clocks, glucose metabolism and insulin sensitivity, and present current evidence for a relationship between circadian disruption and insulin resistance. We conclude by proposing several strategies that aim to use chronobiological knowledge to improve human metabolic health.
Address (down) Netherlands Institute for Neuroscience (NIN), Royal Dutch Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands. a.kalsbeek@nin.knaw.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 1759-5029 ISBN Medium
Area Expedition Conference
Notes PMID:30531917 Approved no
Call Number GFZ @ kyba @ Serial 2133
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Author Aboushelib, M.F.; Abozaid, A.A.; Nawar, S.; Hendy, Y.H.M.; Morcos, A.B.
Title Preliminary site selection for an observatory in the Egyptian Eastern Desert Type Journal Article
Year 2019 Publication Astrophysics and Space Science Abbreviated Journal Astrophys Space Sci
Volume 364 Issue 10 Pages 163
Keywords Skyglow; Astronomy; Observatory; Egypt; Africa; Sky Quality Meter
Abstract This work aims for choosing preliminary sites that can be candidates for a new astronomical observatory that will replace the Kottamia observatory. The candidate sites have been selected to be investigated after proposing a few criteria. Concerning light pollution and elevation of the sites as the main factors, we chose the candidate sites depending on the zenith sky brightness and the elevation. The night sky brightness has been measured using a Sky Quality Meter at different altitude degrees and the values of the zenith sky brightness were compared to those of different observatory sites. Our night sky brightness observations were found to be in agreement with the satellite’s data and comparable to those of dark sites, with average values of 22.07, 22.03, 21.57 and 21.58 magSQM/arcsec2. We also have obtained the Aerosol Optical Depth (AOD) and extinction coefficient due to the aerosol for the candidate sites using satellite data (Terra/MODIS).
Address (down) National Research Institute of Astronomy and Geophysics, Helwan, Cairo, Egypt; m.f.aboushelib(at)nriag.sci.eg
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-640X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2690
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Author Yeh, C.; Perez, A.; Driscoll, A.; Azzari, G.; Tang, Z.; Lobell, D.; Ermon, S.; Burke, M.
Title Using publicly available satellite imagery and deep learning to understand economic well-being in Africa Type Journal Article
Year 2020 Publication Nature Communications Abbreviated Journal Nat Commun
Volume 11 Issue 1 Pages 2583
Keywords Remote Sensing
Abstract Accurate and comprehensive measurements of economic well-being are fundamental inputs into both research and policy, but such measures are unavailable at a local level in many parts of the world. Here we train deep learning models to predict survey-based estimates of asset wealth across ~ 20,000 African villages from publicly-available multispectral satellite imagery. Models can explain 70% of the variation in ground-measured village wealth in countries where the model was not trained, outperforming previous benchmarks from high-resolution imagery, and comparison with independent wealth measurements from censuses suggests that errors in satellite estimates are comparable to errors in existing ground data. Satellite-based estimates can also explain up to 50% of the variation in district-aggregated changes in wealth over time, with daytime imagery particularly useful in this task. We demonstrate the utility of satellite-based estimates for research and policy, and demonstrate their scalability by creating a wealth map for Africa's most populous country.
Address (down) National Bureau of Economic Research, 1050 Massachusetts Avenue, Cambridge, MA, 02138-5398, USA. mburke@stanford.edu
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 2041-1723 ISBN Medium
Area Expedition Conference
Notes PMID:32444658 Approved no
Call Number GFZ @ kyba @ Serial 2939
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