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Artificial Light

María S Gastón, Laura C Pereyra, Marcos Vaira
Light pollution or artificial lighting at night (ALAN) is an emerging threat to biodiversity that can disrupt physiological processes and behaviors. Because ALAN stressful effects are little studied in diurnal amphibian species, we investigated if chronic ALAN exposure affects the leukocyte profile, body condition, and blood cell sizes of a diurnal toad. We hand-captured male toads of Melanophryniscus rubriventris in Angosto de Jaire (Jujuy, Argentina). We prepared blood smears from three groups of toads: "field" (toads processed in the field immediately after capture), "natural light" (toads kept in the laboratory under captivity with natural photoperiod), and "constant light" (toads kept in the laboratory under captivity with constant photoperiod/ALAN)...
October 15, 2018: Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology
Brent M DeVetter, Bruce E Bernacki, Kyle J Alvine
Technologies for directing daylight deeper within a building space are highly sought after for energy efficiency applications in order to offset artificial lighting costs and to improve workplace productivity via the use of natural light. Vertical window coatings that can perform this task by redistributing sunlight deeper into a space are especially attractive as they are significantly more straightforward to incorporate into a wide variety of architectures as well as to retrofit into existing facades as compared to roof-based skylights or bulky horizontal daylight shelf-type options...
October 15, 2018: Optics Letters
Damayanti Bagchi, V S Sharan Rathnam, Peter Lemmens, Indranil Banerjee, Samir Kumar Pal
Nanomaterials with antimicrobial properties triggered by external stimuli appear to be a promising and innovative substitute for the destruction of antibiotic-resistant superbugs as they can induce multiple disruptions in the cellular mechanism. This study demonstrates the use of squaraine (SQ) dye as the photosensitive material, activated in the near-infrared tissue-transparent therapeutic window. The dye has been covalently attached to the ZnO nanoparticle surface, forming ZnO-SQ nanohybrids. The formation of the nanohybrids is confirmed using Fourier transform infrared and other optical spectroscopic methods...
September 30, 2018: ACS Omega
Pau Santos, Juan A Martínez-Roda, Juan C Ondategui, Fernando Díaz-Doutón, Jorge A Ortiz Cazal, Meritxell Vilaseca
Current methods to measure intraocular scattering provide information on the total scattered light, which consists of the combined contributions originating from different ocular structures. In this work, we propose a technique for the objective and independent assessment of scattering caused by the cornea and the lens based on the analysis of the contrast of the third and fourth Purkinje images. The technique is preliminarily validated first by using artificial eyes with different levels of corneal and lens scattering; second, it is validated in eyes wearing customized contact lenses to simulate corneal scattering and eyes with nuclear cataracts...
October 1, 2018: Biomedical Optics Express
Giulio Simone, Dario Di Carlo Rasi, Xander de Vries, Gaël H L Heintges, Stefan C J Meskers, René A J Janssen, Gerwin H Gelinck
Photovoltaic retinal prostheses show great potential to restore sight in patients suffering from degenerative eye diseases by electrical stimulation of the surviving neurons in the retinal network. Herein, organic photodiodes (OPDs) sensitive to near-infrared (NIR) light are evaluated as photovoltaic pixels for future application in retinal prostheses. Single-junction and tandem OPDs are compared. In the latter, two nominally identical single-junction cells are processed on top of each other, effectively doubling the open-circuit voltage (V OC )...
October 15, 2018: Advanced Materials
Sander Bus, Dagmar Verbaan, Bertjan J Kerklaan, Marieke E S Sprengers, William P Vandertop, Jan Stam, Gerrit J Bouma, Pepijn van den Munckhof
PURPOSE: According to the international guidelines, acute subdural hematomas (aSDH) with a thickness of >10 mm, or causing a midline shift of >5 mm, should be surgically evacuated. However, high mortality rates in older patients resulted in ongoing controversy whether elderly patients benefit from surgery. We identified predictors of outcome in a single-centre cohort of elderly patients undergoing surgical evacuation of aSDH or subacute subdural hematoma (saSDH). MATERIALS AND METHODS: This retrospective study included all patients aged ≥65 years undergoing surgical evacuation of aSDH/saSDH from 2000 to 2015...
October 13, 2018: British Journal of Neurosurgery
Henrico Badaoui Strazzi Sahyon, Afonso Chimanski, Humberto Naoyuki Yoshimura, Paulo Henrique Dos Santos
STATEMENT OF PROBLEM: The color stability and mechanical properties of luting agents influence the esthetics and longevity of ceramic restorations. However, studies evaluating the color changes and mechanical properties of luting agents under ceramic laminates activated by using different methods are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the effects of different modes of photoactivation on the nanohardness and elastic modulus of resin cements and dental adhesives and on the color stability of ceramic laminate veneers...
October 2018: Journal of Prosthetic Dentistry
Rachel A Daut, Matthew J Hartsock, Angela C Tomczik, Linda R Watkins, Robert L Spencer, Steven F Maier, Laura K Fonken
In modern 24-h society, circadian disruption is pervasive, arising from night shift work, air travel across multiple time zones, irregular sleep schedules, and exposure to artificial light at night. Disruption of the circadian system is associated with many adverse health consequences, including mood disorders. Here we investigate whether inducing circadian misalignment using a phase advance protocol interferes with the ability to cope with a stressor, thereby increasing susceptibility to the negative consequences of stress...
October 9, 2018: Behavioural Brain Research
Leena Tähkämö, Timo Partonen, Anu-Katriina Pesonen
Light is necessary for life, and artificial light improves visual performance and safety, but there is an increasing concern of the potential health and environmental impacts of light. Findings from a number of studies suggest that mistimed light exposure disrupts the circadian rhythm in humans, potentially causing further health impacts. However, a variety of methods has been applied in individual experimental studies of light-induced circadian impacts, including definition of light exposure and outcomes. Thus, a systematic review is needed to synthesize the results...
October 12, 2018: Chronobiology International
C Reche, M Viana, X Querol, C Corcellas, D Barceló, E Eljarrat
Levels of particle-phase legacy polybrominated diphenyl ethers (PBDEs), and novel brominated and chlorinated flame retardants, such as decabromodiphenyl ethane (DBDPE) and Dechlorane Plus (DP), were measured in ambient outdoor air, indoor workplace air and indoor dust, in different locations across Spain. PBDE concentrations were generally higher in outdoor ambient air samples than in indoor air, ranging between 1.18 and 28.6 pg m-3 , while DP was the main flame retardant (FR) in indoor air (2.90-42.6 pg m-3 )...
February 1, 2019: Science of the Total Environment
H X Zhu, X Q Liu, M D Hu, M M Lei, Z Chen, S J Ying, J N Yu, Z C Dai, Z D Shi
Hungarian White geese are regarded as good producers of meat, eggs, and feathers, but specific lighting schedules are required to improve their egg-laying performance. This study reveals the neuroendocrine regulatory mechanisms that govern the reproductive activities and egg-laying performances of Hungarian White geese. The results indicated that increasing the daily photoperiod from a short 8 h period to either 11 h or 14 h initiated reproduction. Egg-laying rates increased faster in the 14 h group, peaking (48...
October 3, 2018: Theriogenology
Olivier Kaisin, Eva Gazagne, Tommaso Savini, Marie-Claude Huynen, Fany Brotcorne
Bird egg predation is widespread in non-human primates. Although nest predation is often described as opportunistic, little is known about foraging strategies and nest detection in primates. Since it is the prevalent cause of nest failure in the tropics, birds select nest sites within specific microhabitats and use different nest types to increase nesting success. Identifying the nests targeted by the northern pigtailed macaques (Macaca leonina), an omnivorous cercopithecine species, and known nest predator, will shine light on nest foraging strategies in primates...
October 11, 2018: American Journal of Primatology
Maggie C Evans, Greg M Anderson
Optimal fertility in humans and animals relies on the availability of sufficient metabolic fuels, information about which is communicated to the brain via levels of the hormones leptin and insulin. The circadian clock system is also critical; this input is particularly evident in the precise timing of the female-specific surge of GnRH and LH secretion that triggers ovulation on the following day. Chronodisruption or metabolic imbalance can both impair reproductive activity, and these two disruptions exacerbate each other, such that they often occur simultaneously...
October 9, 2018: Endocrinology
Joseph Marlow, Simon K Davy, Abdul Haris, James J Bell
Watershed-based pollution is a common form of coral reef degradation. Affected reefs are often highly turbid, where light-limitation confines the distribution of photosynthetic benthic taxa and the capacity for photoacclimation is important for survival. We investigated low light photoacclimation in a Symbiodinium-hosting bioeroding sponge using in situ PAM fluorometry. Cliona aff. viridis was artificially shaded (70 & 95% ambient light reduction) on a low turbidity Indonesian reef for 25 days, with a subsequent 14-day recovery period...
October 2018: Marine Pollution Bulletin
Marziyeh Ghaeidamini, Ali Nemati Kharat, Thomas Haertlé, Faizan Ahmad, Ali Akbar Saboury
In this manuscript, we propose an impressive and facile strategy to improve protein refolding using solid phase artificial molecular chaperones consisting of the surface-functionalized magnetic nanoparticles. Specifically, mono-tosyl-β-cyclodextrin (Ts-β-CD) connected to the surface of 3-aminopropyltriethoxysilane (APES) - modified magnetic nanoparticles (APES-MNPs), is immobilized on the Sepharose surface to promote interaction with exposed hydrophobic surfaces of partially folded (intermediates) and unfolded states of proteins...
October 9, 2018: Journal of Physical Chemistry. B
Hossam Hamdy
The complexity of medical education and healthcare systems is a 'wicked problem'. Change will be a continuous iteration between evaluation and revaluation. Medicine is a social science. It is about people, societies and human interaction and communication. Medical College of the future should be developed in the light of social constructivism theories. Students from year one, day one, should be embedded in the work environment. Academic Healthcare Systems will be the norm not the exceptional. The training of students will be in all healthcare related facilities in the community...
October 9, 2018: Medical Teacher
Peijun Guo, Wei Huang, Constantinos C Stoumpos, Lingling Mao, Jue Gong, Li Zeng, Benjamin T Diroll, Yi Xia, Xuedan Ma, David J Gosztola, Tao Xu, John B Ketterson, Michael J Bedzyk, Antonio Facchetti, Tobin J Marks, Mercouri G Kanatzidis, Richard D Schaller
Excitations of free electrons and optical phonons are known to permit access to the negative real part of relative permittivities (ϵ^{'}<0) that yield strong light-matter interactions. However, negative ϵ^{'} arising from excitons has been much less explored. Via development of a dielectric-coating based technique described herein, we report fundamental optical properties of two-dimensional hybrid perovskites (2DHPs), composed of alternating layers of inorganic and organic sublattices. Low members of 2DHPs (N=1 and N=2) exhibit negative ϵ^{'} stemming from the large exciton binding energy and sizable oscillator strength...
September 21, 2018: Physical Review Letters
Shuang Meng, Aimin Duan, Jiadan Xue, Xuming Zheng, Yanying Zhao
The microsolvation and photophysics of 3-amino-1,2,4-triazole (3AT) after excitation to the light-absorbing S2(nπ*) state were studied by using resonance Raman spectroscopy and single component artificial force-induced reaction (SC-AFIR) in a global reaction route mapping (GRRM) strategy. The vibrational spectra were assigned on the basis of experimental data and density functional theory (DFT) calculations. The A-band resonance Raman spectra of 3AT were measured to probe the excited state structural dynamics in the Franck-Condon region...
October 8, 2018: Journal of Physical Chemistry. A
Haiyang Jia, Lei Kai, Michael Heymann, Daniela A García-Soriano, Tobias Härtel, Petra Schwille
Reconstituting functional modules of biological systems in vitro is an important yet challenging goal of bottom-up synthetic biology, in particular with respect to their precise spatiotemporal regulation. One of the most desirable external control parameters for the engineering of biological systems is visible light, owing to its specificity and ease of defined application in space and time. Here we engineered the PhyB-PIF6 system to spatiotemporally target proteins by light onto model membranes and thus sequentially guide protein pattern formation and structural assembly in vitro from the bottom up...
October 8, 2018: Nano Letters
Matt R K Zeale, Emma L Stone, Emma Zeale, William J Browne, Stephen Harris, Gareth Jones
The rapid global spread of artificial light at night is causing unprecedented disruption to ecosystems. In otherwise dark environments, street lights restrict the use of major flight routes by some bats, including the threatened lesser horseshoe bat Rhinolophus hipposideros, and may disrupt foraging. Using radio tracking, we examined the response of individual female R. hipposideros to experimental street lights placed on hedgerows used as major flight routes. Hedgerows were illuminated on one side over four nights using lights with different emission spectra, while the opposite side of the hedge was not illuminated...
October 4, 2018: Global Change Biology
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