496 research outputs found

    Current Approaches in Arabic IR: A Survey

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    Arabic information retrieval is a popular area of research. This paper presents the current state-of-the-art in Arabic Information Retreival (IR) approaches. Moreover, it provides general guidance for open research areas and future directions

    MeshfreeFlowNet: A Physics-Constrained Deep Continuous Space-Time Super-Resolution Framework

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    We propose MeshfreeFlowNet, a novel deep learning-based super-resolution framework to generate continuous (grid-free) spatio-temporal solutions from the low-resolution inputs. While being computationally efficient, MeshfreeFlowNet accurately recovers the fine-scale quantities of interest. MeshfreeFlowNet allows for: (i) the output to be sampled at all spatio-temporal resolutions, (ii) a set of Partial Differential Equation (PDE) constraints to be imposed, and (iii) training on fixed-size inputs on arbitrarily sized spatio-temporal domains owing to its fully convolutional encoder. We empirically study the performance of MeshfreeFlowNet on the task of super-resolution of turbulent flows in the Rayleigh-Benard convection problem. Across a diverse set of evaluation metrics, we show that MeshfreeFlowNet significantly outperforms existing baselines. Furthermore, we provide a large scale implementation of MeshfreeFlowNet and show that it efficiently scales across large clusters, achieving 96.80% scaling efficiency on up to 128 GPUs and a training time of less than 4 minutes. We provide an open-source implementation of our method that supports arbitrary combinations of PDE constraints

    Multilevel Inverter by using Switching Capacitor in PV Grid

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    Abstract: In this paper, we are using multilevel inverter by using switching capacitor for PV grid. Now a day's multilevel inverters have become more popular over the years in electric high power application with the promise of less disturbances and the possibility to function at lower switching frequencies than ordinary two-level inverters. So by cascading multilevel inverter the output voltage will be increases. By using multilevel inverter the cost will be less. It will be required less space. Modulation strategies, component comparison and solutions to the multilevel voltage source balancing problem will also be presented in this work. By using the multilevel inverter we can reduce the total harmonic distraction compare to the other sources in PV grid for DC to AC converter. The proposed method is simulated in Matlab Simulink

    Metabolic changes of salicylic acid-elicited Catharanthus roseus cell suspension cultures monitored by NMR-based metabolomics

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    The effect of salicylic acid (SA) on the metabolic profile of Catharanthus roseus suspension cells throughout a time course (0, 6, 12, 24, 48 and 72 h after treatment) was investigated using NMR spectroscopy and multivariate data analysis. When compared to control cell lines, SA-treated cells showed a high level of sugars (glucose and sucrose) up to 48 h after treatment, followed by a dynamic change in amino acids, phenylpropanoids, and tryptamine. Additionally, one compound—2,5-dihydroxybenzoic-5-O-glucoside—was detected solely in SA-treated cells

    Metabolome-wide association study on ABCA7 indicates a role of ceramide metabolism in Alzheimer's disease.

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    Genome-wide association studies (GWASs) have identified genetic loci associated with the risk of Alzheimer's disease (AD), but the molecular mechanisms by which they confer risk are largely unknown. We conducted a metabolome-wide association study (MWAS) of AD-associated loci from GWASs using untargeted metabolic profiling (metabolomics) by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS). We identified an association of lactosylceramides (LacCer) with AD-related single-nucleotide polymorphisms (SNPs) in ABCA7 (P = 5.0 × 10-5 to 1.3 × 10-44). We showed that plasma LacCer concentrations are associated with cognitive performance and genetically modified levels of LacCer are associated with AD risk. We then showed that concentrations of sphingomyelins, ceramides, and hexosylceramides were altered in brain tissue from Abca7 knockout mice, compared with wild type (WT) (P = 0.049-1.4 × 10-5), but not in a mouse model of amyloidosis. Furthermore, activation of microglia increases intracellular concentrations of hexosylceramides in part through induction in the expression of sphingosine kinase, an enzyme with a high control coefficient for sphingolipid and ceramide synthesis. Our work suggests that the risk for AD arising from functional variations in ABCA7 is mediated at least in part through ceramides. Modulation of their metabolism or downstream signaling may offer new therapeutic opportunities for AD
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