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https://www.readbyqxmd.com/read/29326985/use-of-an-autonomous-surface-vehicle-reveals-small-scale-diel-vertical-migrations-of-zooplankton-and-susceptibility-to-light-pollution-under-low-solar-irradiance
#1
Martin Ludvigsen, Jørgen Berge, Maxime Geoffroy, Jonathan H Cohen, Pedro R De La Torre, Stein M Nornes, Hanumant Singh, Asgeir J Sørensen, Malin Daase, Geir Johnsen
Light is a major cue for nearly all life on Earth. However, most of our knowledge concerning the importance of light is based on organisms' response to light during daytime, including the dusk and dawn phase. When it is dark, light is most often considered as pollution, with increasing appreciation of its negative ecological effects. Using an Autonomous Surface Vehicle fitted with a hyperspectral irradiance sensor and an acoustic profiler, we detected and quantified the behavior of zooplankton in an unpolluted light environment in the high Arctic polar night and compared the results with that from a light-polluted environment close to our research vessels...
January 2018: Science Advances
https://www.readbyqxmd.com/read/29325109/estimating-adolescent-sleep-need-using-dose-response-modelling
#2
Michelle A Short, Nathan Weber, Chelsea Reynolds, Scott Coussens, Mary A Carskadon
Study Objectives: This study will, (a) estimate the nightly sleep need of human adolescents, (b) determine the time course and severity of sleep-related deficits when sleep is reduced below this optimal quantity, and (c) determine whether sleep restriction perturbs the circadian system as well as the sleep homeostat. Methods: Thirty-four adolescents aged 15 to 17 years spent 10 days and 9 nights in the sleep laboratory. Between two baseline nights and two recovery nights with 10-hours' time in bed (TIB) per night, participants experienced either severe sleep restriction (5-hr TIB), moderate sleep restriction (7...
January 6, 2018: Sleep
https://www.readbyqxmd.com/read/29318392/relationship-between-melatonin-and-bone-resorption-rhythms-in-premenopausal-women
#3
Melissa A St Hilaire, Shadab A Rahman, Joshua J Gooley, Paula A Witt-Enderby, Steven W Lockley
Although evidence exists for a daily rhythm in bone metabolism, the contribution of factors such as melatonin levels, the light-dark cycle, and the sleep-wake cycle is difficult to differentiate given their highly correlated time courses. To examine these influences on bone resorption, we collected 48-h sequential urine samples under both ambulatory (8-h sleep:16-h wake) and constant routine (CR) (constant wake, posture, nutrition and dim light) conditions from 20 healthy premenopausal women. Urinary 6-sulphatoxymelatonin (aMT6s; ng/h) and the bone resorption marker amino-terminal cross-linked collagen I telopeptide (NTx; bone collagen equivalents nM/h) were assayed and fit by cosinor models to determine significant 24-h rhythms and acrophase...
January 9, 2018: Journal of Bone and Mineral Metabolism
https://www.readbyqxmd.com/read/29300449/alkoxybenzothiadiazole-based-fullerene-and-nonfullerene-polymer-solar-cells-with-high-shunt-resistance-for-indoor-photovoltaic-applications
#4
Song Yi Park, Yuxiang Li, Jaewon Kim, Tack Ho Lee, Bright Walker, Han Young Woo, Jin Young Kim
We synthesized three semi-crystalline polymers (PTTBTBO, PDTBTBO, and P2FDTBTBO) by modulating the intra- and intermolecular noncovalent coulombic interactions, and investigated their photovoltaic characteristics under various light intensities. Low series (Rs) and high shunt (Rsh) resistances are essential prerequisites for good device properties under standard illumination (100 mW cm-2). Considering these factors, among three polymers PDTBTBO polymer solar cells (PSCs) exhibited the most desirable characteristics, with peak power conversion efficiencies (PCE) of 7...
January 4, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29299909/chromatic-titanium-photoanode-for-dye-sensitized-solar-cells-under-rear-illumination
#5
Chih-Hsiang Huang, Yu-Wen Chen, Chih-Ming Chen
Titanium (Ti) has high potential in many practical applications such as biomedicine, architecture, aviation, and energy. In this study, we demonstrate an innovative application of dye-sensitized solar cell (DSSC) based on Ti photoanode that can be integrated into the roof engineering of large-scale architectures. A chromatic Ti foil produced by anodizing oxidation (coloring) technology (AOT) is an attractive roof material for large-scale architecture, showing a colorful appearance due to the formation of a reflective TiO2 thin layer on both surfaces of Ti...
January 4, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29294967/perpetration-and-experience-of-intimate-partner-violence-among-residents-in-bariga-local-community-development-area-lagos-state-nigeria
#6
Emeka Eugene Dim, Oluseyi Ogunye
The occurrence of aggressive behavior in intimate relationships carries serious mental and physical health consequences for the victims and children exposed to such events. Studies have been devoted toward understanding the nature and prevalence of the phenomenon; however, there has been a paucity of empirical investigation into the complexities and nuances of the subject matter, and this study seeks to address one of such complexities. This study examines the dynamics of intimate partner violence (IPV) within the context of perpetration and victimization among residents in Bariga Local Community Development Area in Lagos State, Nigeria...
October 1, 2017: Journal of Interpersonal Violence
https://www.readbyqxmd.com/read/29276475/evolution-development-and-function-of-vertebrate-cone-oil-droplets
#7
REVIEW
Matthew B Toomey, Joseph C Corbo
To distinguish colors, the nervous system must compare the activity of distinct subtypes of photoreceptors that are maximally sensitive to different portions of the light spectrum. In vertebrates, a variety of adaptations have arisen to refine the spectral sensitivity of cone photoreceptors and improve color vision. In this review article, we focus on one such adaptation, the oil droplet, a unique optical organelle found within the inner segment of cone photoreceptors of a diverse array of vertebrate species, from fish to mammals...
2017: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/29251803/light-modulates-hippocampal-function-and-spatial-learning-in-a-diurnal-rodent-species-a-study-using-male-nile-grass-rat-arvicanthis-niloticus
#8
Joel E Soler, Alfred J Robison, Antonio A Núñez, Lily Yan
The effects of light on cognitive function have been well-documented in human studies, with brighter illumination improving cognitive performance in school children, healthy adults and patients in early stages of dementia. However, the underlying neural mechanisms are not well understood. The present study examined how ambient light affects hippocampal function using the diurnal Nile grass rats (Arvicanthis niloticus) as the animal model. Grass rats were housed in either a 12:12hr bright light-dark (brLD, 1000 lux) or dim light-dark (dimLD, 50 lux) cycle...
December 18, 2017: Hippocampus
https://www.readbyqxmd.com/read/29217689/dopamine-dependent-sensitization-of-rod-bipolar-cells-by-gaba-is-conveyed-through-wide-field-amacrine-cells
#9
Amanda M Travis, Stephanie J Heflin, Arlene A Hirano, Nicholas C Brecha, Vadim Y Arshavsky
Vertebrate retina has the remarkable ability to support visual function under conditions of limited illumination, including processing signals evoked by single photons. Dim light vision is regulated by several adaptive mechanisms. The mechanism explored in this study is responsible for increasing the light sensitivity and operational range of rod bipolar cells, the retinal neurons operating immediately downstream of rod photoreceptors. This sensitization is achieved through the sustained dopamine-dependent GABA release from other retinal neurons...
December 6, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29217196/short-term-exposure-to-dim-light-at-night-disrupts-rhythmic-behaviors-and-causes-neurodegeneration-in-fly-models-of-tauopathy-and-alzheimer-s-disease
#10
Mari Kim, Manivannan Subramanian, Yun-Ho Cho, Gye-Hyeong Kim, Eunil Lee, Joong-Jean Park
The accumulation and aggregation of phosphorylated tau proteins in the brain are the hallmarks for the onset of Alzheimer's disease (AD). In addition, disruptions in circadian rhythms (CRs) with altered sleep-wake cycles, dysregulation of locomotion, and increased memory defects have been reported in patients with AD. Drosophila flies that have an overexpression of human tau protein in neurons exhibit most of the symptoms of human patients with AD, including locomotion defects and neurodegeneration. Using the fly model for tauopathy/AD, we investigated the effects of an exposure to dim light at night on AD symptoms...
December 4, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/29206864/high-visual-acuity-revealed-in-dogs
#11
Olle Lind, Ida Milton, Elin Andersson, Per Jensen, Lina S V Roth
Humans have selectively bred and used dogs over a period of thousands of years, and more recently the dog has become an important model animal for studies in ethology, cognition and genetics. These broad interests warrant careful descriptions of the senses of dogs. Still there is little known about dog vision, especially what dogs can discriminate in different light conditions. We trained and tested whippets, pugs, and a Shetland sheepdog in a two-choice discrimination set-up and show that dogs can discriminate patterns with spatial frequencies between 5...
2017: PloS One
https://www.readbyqxmd.com/read/29198969/validation-of-a-touchscreen-psychomotor-vigilance-task
#12
Lucia Arsintescu, Kenji H Kato, Patrick F Cravalho, Nathan H Feick, Leland S Stone, Erin E Flynn-Evans
OBJECTIVE: The purpose of this study was to compare a psychomotor vigilance task developed for use on touchscreen devices with the original PVT-192 in conditions of acute sleep loss and circadian desynchronization. BACKGROUND: The Psychomotor Vigilance Task (PVT) is considered the gold standard fatigue detection test and is used frequently in fatigue research. With the rapid development of new technologies it is essential to develop a PVT available on different platforms such as touchscreen devices...
November 30, 2017: Accident; Analysis and Prevention
https://www.readbyqxmd.com/read/29198295/the-effect-of-systematic-light-exposure-on-sleep-in-a-mixed-group-of-fatigued-cancer-survivors
#13
Lisa M Wu, Ali Amidi, Heiddis Valdimarsdottir, Sonia Ancoli-Israel, Lianqi Liu, Gary Winkel, Emily E Byrne, Ana Vallejo Sefair, Alejandro Vega, Katrin Bovbjerg, William H Redd
STUDY OBJECTIVES: Sleep disturbances are commonly reported by cancer survivors. Systematic light exposure using bright light has been used to improve sleep in other populations. In this secondary data analysis, the effect of morning administration of bright light on sleep and sleep quality was examined in a mixed group of fatigued cancer survivors. METHODS: Forty-four cancer survivors screened for cancer-related fatigue were randomized to either a bright white light or a comparison dim red light condition...
November 29, 2017: Journal of Clinical Sleep Medicine: JCSM: Official Publication of the American Academy of Sleep Medicine
https://www.readbyqxmd.com/read/29187620/ocellar-structure-is-driven-by-the-mode-of-locomotion-and-activity-time-in-myrmecia-ants
#14
Ajay Narendra, Willi A Ribi
Insects have exquisitely adapted their compound eyes to suit the ambient light intensity in the different temporal niches they occupy. In addition to the compound eye, most flying insects have simple eyes known as ocelli, which assist in flight stabilisation, horizon detection and orientation. Among ants, typically the flying alates have ocelli while the pedestrian workers lack this structure. The Australian ant genus Myrmecia is one of the few ant genera in which both workers and alates have three ocellar lenses...
December 1, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/29182469/semistructured-observation-of-population-based-eye-screening-in-the-netherlands
#15
Frea Sloot, Aya Sami, Hatice Karaman, Mari Gutter, Janine Benjamins, Trijntje Sjoerdsma, Huibert Jan Simonsz
BACKGROUND: In the Netherlands, youth-healthcare (YHC) physicians screen children 7 times for vision disorders between the ages of 1 and 60 months. Examination consists of inspection of the external structures of the eye, fundus red reflex, Hirschberg test, pupillary reflexes, cover-uncover test, alternating-cover test, eye motility, monocular pursuit, and, from 36 months onwards, visual acuity (VA). We observed how well these tests are done. METHODS: Screening test performance was assessed with semistructured observations...
November 28, 2017: Strabismus
https://www.readbyqxmd.com/read/29180667/rods-progressively-escape-saturation-to-drive-visual-responses-in-daylight-conditions
#16
Alexandra Tikidji-Hamburyan, Katja Reinhard, Riccardo Storchi, Johannes Dietter, Hartwig Seitter, Katherine E Davis, Saad Idrees, Marion Mutter, Lauren Walmsley, Robert A Bedford, Marius Ueffing, Petri Ala-Laurila, Timothy M Brown, Robert J Lucas, Thomas A Münch
Rod and cone photoreceptors support vision across large light intensity ranges. Rods, active under dim illumination, are thought to saturate at higher (photopic) irradiances. The extent of rod saturation is not well defined; some studies report rod activity well into the photopic range. Using electrophysiological recordings from retina and dorsal lateral geniculate nucleus of cone-deficient and visually intact mice, we describe stimulus and physiological factors that influence photopic rod-driven responses...
November 27, 2017: Nature Communications
https://www.readbyqxmd.com/read/29176713/rapid-resetting-of-human-peripheral-clocks-by-phototherapy-during-simulated-night-shift-work
#17
Marc Cuesta, Philippe Boudreau, Nicolas Cermakian, Diane B Boivin
A majority of night shift workers have their circadian rhythms misaligned to their atypical schedule. While bright light exposure at night is known to reset the human central circadian clock, the behavior of peripheral clocks under conditions of shift work is more elusive. The aim of the present study was to quantify the resetting effects of bright light exposure on both central (plasma cortisol and melatonin) and peripheral clocks markers (clock gene expression in peripheral blood mononuclear cells, PBMCs) in subjects living at night...
November 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29166586/the-broad-spectrum-of-human-natural-killer-cell-diversity
#18
REVIEW
Aharon G Freud, Bethany L Mundy-Bosse, Jianhua Yu, Michael A Caligiuri
Natural killer (NK) cells provide protection against infectious pathogens and cancer. For decades it has been appreciated that two major NK cell subsets (CD56bright and CD56dim) exist in humans and have distinct anatomical localization patterns, phenotypes, and functions in immunity. In light of this traditional NK cell dichotomy, it is now clear that the spectrum of human NK cell diversity is much broader than originally appreciated as a result of variegated surface receptor, intracellular signaling molecule, and transcription factor expression; tissue-specific imprinting; and foreign antigen exposure...
November 21, 2017: Immunity
https://www.readbyqxmd.com/read/29161162/patient-perceived-and-laboratory-measured-halos-associated-with-diffractive-bifocal-and-trifocal-intraocular-lenses
#19
Francisco Alba-Bueno, Nuria Garzón, Fidel Vega, Francisco Poyales, María S Millán
PURPOSE: To examine and assess the halos generated in distance vision by multifocal intraocular lenses (IOLs) using both in vitro objective and in vivo subjective methods. SETTING: The objective method was carried out in the optics laboratory of the Applied Optics and Image Processing Group (Universitat Politècnica de Catalunya -Barcelona). The psychophysical and subjective methods were carried out in the Instituto de Oftalmología Avanzada Madrid Innova Ocular...
November 21, 2017: Current Eye Research
https://www.readbyqxmd.com/read/29152732/in-home-salivary-melatonin-collection-methodology-for-children-and-adolescents
#20
Belinda N Mandrell, Yvonne Avent, Breya Walker, Megan Loew, Brooklee Lightsey Tynes, Valerie McLaughlin Crabtree
In-home salivary collection quality and adherence to a prescribed collection methodology for evaluation of dim light melatonin onset (DLMO) is unknown in children. Primary aims of this study were to 1) describe a novel family centered methodology for in-home salivary collection; 2) determine the acceptance and feasibility of this methodology; 3) measure adherence to collection instructions; and 4) identify patterns between participants' age and quality of samples collected. After receiving instructional handouts from the study team, families utilized in-home salivary melatonin collection...
November 20, 2017: Developmental Psychobiology
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