106 research outputs found

    Distance Learning in Emergencies: Social and Pedagogical Relations in the Context of the COVID-19 Pandemic

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    The current study aims to investigate social and pedagogical relations during the experience of distance learning in emergencies, in the context of the spread of the Covid-19 pandemic. The study identifies the impact of the transition towards this new system in rebuilding social and pedagogical links between professors and students through a case study at Ajman University, as one of the institutions of higher education in the United Arab Emirates. The study relied on the quantitative approach and the sample of the study consisted of (730) students selected in a simple random manner. The study found that most of the sample members had advanced infrastructure that would enable them to keep up with the transition to the distance learning system, and that the level of access to electronic tools and distance learning platforms and the ability to deal with them were high. The study also found that the distance learning system increases the level of interaction, discussion and communication between students and between students and teachers, which extends beyond the lesson period, as an attempt to replace direct interaction

    Further biochemical profiling of Hypholoma fasciculare metabolome reveals its chemo-genetic diversity

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    Natural products with novel chemistry are urgently needed to battle the continued increase in microbial drug resistance. Mushroom-forming fungi are underutilized as a source of novel antibiotics in the literature due to their challenging culture preparation and genetic intractability. However, modern fungal molecular and synthetic biology tools have renewed interest in exploring mushroom fungi for novel therapeutic agents. The aims of this study were to investigate the secondary metabolites of nine basidiomycetes, screen their biological and chemical properties, and then investigate the genetic pathways associated with their production. Of the nine fungi selected, was revealed to be a highly active antagonistic species, with antimicrobial activity against three different microorganisms: , , and . Genomic comparisons and chromatographic studies were employed to characterize more than 15 biosynthetic gene clusters and resulted in the identification of 3,5-dichloromethoxy benzoic acid as a potential antibacterial compound. The biosynthetic gene cluster for this product is also predicted. This study reinforces the potential of mushroom-forming fungi as an underexplored reservoir of bioactive natural products. Access to genomic data, and chemical-based frameworks, will assist the development and application of novel molecules with applications in both the pharmaceutical and agrochemical industries

    Surface-related properties of perovskite CH3NH3PbI3 thin films by aerosol-assisted chemical vapour deposition

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    A modified three-step aerosol-assisted chemical vapour deposition process was used to grow dense and uniform CH3NH3PbI3 thin films directly on borosilicate glass. The resulting photoluminescence spectrum was blue shifted with respect to its bandgap. X-ray photoelectron spectroscopy studies confirmed non-stoichiometric lead : iodine ratios within the films, due to decomposition of the CH3NH3PbI3 layers over time into lead iodide and the release of ammonia and hydrogen iodide. The complex refractive index and dielectric function of the deposited thin films were determined by variable angle spectroscopic ellipsometry

    Understanding nanomechanical and surface ellipsometry of optical F-doped SnO2 thin films by in-line APCVD

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    In this paper, a production-type chemical vapour deposition (CVD) is utilized to deposit fluorine doped tin oxide thin films of different thicknesses and dopant levels. Deposited films showed a preferred orientation along the (200) plane of a tetragonal structure due to the formation of halogen rich polar molecules during the process. A holistic approach studying elastic modulus and hardness of resulting films by a high-throughput atmospheric-pressure CVD process is described. The hardness values determined lie between 8 - 20 GPa. For a given load, the modulus generally increased slightly with the thickness. The average elastic recovery for the coatings was found to be between 45 – 50 %. Refractive index and thickness values derived from the fitted ellipsometry data were in excellent agreement with independent calculations from transmission and reflection data

    Radiogenomics in clear cell renal cell carcinoma: Correlations between advanced CT imaging (texture analysis) and microRNAs expression

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    A relevant challenge for the improvement of clear cell renal cell carcinoma management could derive from the identification of novel molecular biomarkers that could greatly improve the diagnosis, prognosis, and treatment choice of these neoplasms. In this study, we investigate whether quantitative parameters obtained from computed tomography texture analysis (CTTA) may correlate with the expression of selected oncogenic microRNAs (miRNA). To the best of our knowledge, a possible correlation between CT texture parameters and miRNAs expression in ccRCC was not investigated yet

    Expression Profile of Nuclear Receptors along Male Mouse Nephron Segments Reveals a Link between ERRβ and Thick Ascending Limb Function

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    The nuclear receptor family orchestrates many functions related to reproduction, development, metabolism, and adaptation to the circadian cycle. The majority of these receptors are expressed in the kidney, but their exact quantitative localization in this ultrastructured organ remains poorly described, making it difficult to elucidate the renal function of these receptors. In this report, using quantitative PCR on microdissected mouse renal tubules, we established a detailed quantitative expression map of nuclear receptors along the nephron. This map can serve to identify nuclear receptors with specific localization. Thus, we unexpectedly found that the estrogen-related receptor β (ERRβ) is expressed predominantly in the thick ascending limb (TAL) and, to a much lesser extent, in the distal convoluted tubules. In vivo treatment with an ERR inverse agonist (diethylstilbestrol) showed a link between this receptor family and the expression of the Na+,K+-2Cl− cotransporter type 2 (NKCC2), and resulted in phenotype presenting some similarities with the Bartter syndrom (hypokalemia, urinary Na+ loss and volume contraction). Conversely, stimulation of ERRβ with a selective agonist (GSK4716) in a TAL cell line stimulated NKCC2 expression. All together, these results provide broad information regarding the renal expression of all members of the nuclear receptor family and have allowed us to identify a new regulator of ion transport in the TAL segments

    The incorporation of fixed cost and multilevel capacities into the discrete and continuous single source capacitated facility location problem

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    In this study we investigate the single source location problem with the presence of several possible capacities and the opening (fixed) cost of a facility that is depended on the capacity used and the area where the facility is located. Mathematical models of the problem for both the discrete and the continuous cases using the Rectilinear and Euclidean distances are produced. Our aim is to find the optimal number of open facilities, their corresponding locations, and their respective capacities alongside the assignment of the customers to the open facilities in order to minimise the total fixed and transportation costs. For relatively large problems, two solution methods are proposed namely an iterative matheuristic approach and VNS-based matheuristic technique. Dataset from the literature is adapted to assess our proposed methods. To assess the performance of the proposed solution methods, the exact method is first applied to small size instances where optimal solutions can be identified or lower and upper bounds can be recorded. Results obtained by the proposed solution methods are also reported for the larger instances
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