19,418 research outputs found

    Tetrisation of triangular meshes and its application in shape blending

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    The As-Rigid-As-Possible (ARAP) shape deformation framework is a versatile technique for morphing, surface modelling, and mesh editing. We discuss an improvement of the ARAP framework in a few aspects: 1. Given a triangular mesh in 3D space, we introduce a method to associate a tetrahedral structure, which encodes the geometry of the original mesh. 2. We use a Lie algebra based method to interpolate local transformation, which provides better handling of rotation with large angle. 3. We propose a new error function to compile local transformations into a global piecewise linear map, which is rotation invariant and easy to minimise. We implemented a shape blender based on our algorithm and its MIT licensed source code is available online

    Evaluating Learner Perceptions of Use of Simulations for New nurses – A Collaboration Between the UT SON and the Methodist Hospital

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    The purpose of this evaluation project was to describe the integration of simulation into a nursing internship program and to help prepare new graduate nurses for patient care. Additionally, learning styles and perceptions of active learning, collaboration among peers, ways of learning, expectation of simulation, satisfaction, self-confidence, and design of simulation were examined. [See PDF for complete abstract

    Research strategies in molecular signaling of neuronal apoptosis in Alzheimer's disease

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    Dynamic consolidation problems in saturated soils solved through u-w formulation in a LME meshfree framework

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    A meshfree numerical model, based on the principle of Local Maximum Entropy (LME), including a B-bar algorithm to avoid instabilities, is applied to solve axisymmetric consolidation problems in elastic saturated soils. This numerical scheme has been previously validated for purely elastic problems without water (mono phase), as well as for steady seepage in elastic porous media. Hereinafter, an implementation of the novel numerical method in the axisymmetric configuration is proposed, and the model is validated for well known theoretical problems of consolidation in saturated soils, under both static and dynamic conditions with available analytical solutions. The solutions obtained with the new methodology are compared with a finite element commercial software for a set of examples. After validated, solutions for dynamic radial consolidation and sinks, which have not been found elsewhere in the literature, are presented as a novelty. This new numerical approach is demonstrated to be feasible for this kind of problems in porous media, particularly for high frequency, dynamic problems, for which very few results have been found in the literature in spite of their high practical importance

    Entanglement generation outside a Schwarzschild black hole and the Hawking effect

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    We examine the Hawking effect by studying the asymptotic entanglement of two mutually independent two-level atoms placed at a fixed radial distance outside a Schwarzschild black hole in the framework of open quantum systems. We treat the two-atom system as an open quantum system in a bath of fluctuating quantized massless scalar fields in vacuum and calculate the concurrence, a measurement of entanglement, of the equilibrium state of the system at large times, for the Unruh, Hartle-Hawking and Boulware vacua respectively. We find, for all three vacuum cases, that the atoms turn out to be entangled even if they are initially in a separable state as long as the system is not placed right at the even horizon. Remarkably, only in the Unruh vacuum, will the asymptotic entanglement be affected by the backscattering of the thermal radiation off the space-time curvature. The effect of the back scatterings on the asymptotic entanglement cancels in the Hartle-Hawking vacuum case.Comment: 15 pages, no figures, Revte

    Polysaccharides from wolfberry antagonizes glutamate excitotoxicity in rat cortical neurons

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    Glutamate excitotoxicity is involved in many neurodegenerative diseases including Alzheimer's disease (AD). Attenuation of glutamate toxicity is one of the therapeutic strategies for AD. Wolfberry (Lycium barbarum) is a common ingredient in oriental cuisines. A number of studies suggest that wolfberry has anti-aging properties. In recent years, there is a trend of using dried Wolfberry as food supplement and health product in UK and North America. Previously, we have demonstrated that a fraction of polysaccharide from Wolfberry (LBA) provided remarkable neuroprotective effects against beta-amyloid peptide-induced cytotoxicity in primary cultures of rat cortical neurons. To investigate whether LBA can protect neurons from other pathological factors such as glutamate found in Alzheimer brain, we examined whether it can prevent neurotoxicity elicited by glutamate in primary cultured neurons. The glutamate-induced cell death as detected by lactate dehydrogenase assay and caspase-3-like activity assay was significantly reduced by LBA at concentrations ranging from 10 to 500 μg/ml. Protective effects of LBA were comparable to memantine, a non-competitive NMDA receptor antagonist. LBA provided neuroprotection even 1 h after exposure to glutamate. In addition to glutamate, LBA attenuated N-methyl-d-aspartate (NMDA)-induced neuronal damage. To further explore whether LBA might function as antioxidant, we used hydrogen peroxide (H2O2) as oxidative stress inducer in this study. LBA could not attenuate the toxicity of H2O2. Furthermore, LBA did not attenuate glutamate-induced oxidation by using NBT assay. Western blot analysis indicated that glutamate-induced phosphorylation of c-jun N-terminal kinase (JNK) was reduced by treatment with LBA. Taken together, LBA exerted significant neuroprotective effects on cultured cortical neurons exposed to glutamate. © 2009 Springer Science+Business Media, LLC.postprin

    Meshfree numerical schemes applied to seepage problems through earth dams

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    Modelling seepage along with the mechanical responses of deformable Earth Dams under transient conditions is a challenging task, since both coupling between different phases, and computation of free-surface variables are involved. In the present work, we take on the meshfree numerical schemes to establish a framework for solving coupled, transient problems for unconfined seepage through Earth Dams. The equations of Biot are formulated in displacement (or u − w formulation) assuming an elastic solid skeleton. Shape functions based on the principle of Maximum Entropy are implemented for the meshfree framework. The free surface location and its evolution in time, is obtained by interpolation of pore water pressures through the domain. Applications to benchmark problems are compared with available results in the literature. The preliminary simulations for steady flow conditions show promising results

    Neuroprotective effects of minocycline on double-stranded RNA-induced neurotoxicity in cultured cortical neurons

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    1. Minocycline, memantine,and glycoconjugate were assessed for their ability to protect cultured primary cortical neurons against double-stranded RNA-induced neurotoxicity. 2. Minocycline but not memantine or glycoconjugate protected cultured cells and warrants further investigation.published_or_final_versio

    Systematic review recommends the European Organization for Research and Treatment of Cancer colorectal cancer–specific module for measuring quality of life in colorectal cancer patients

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    Objectives: To critically appraise the measurement properties of standardized health-related quality of life (HRQOL) instruments for colorectal cancer (CRC) patients and to provide recommendations on the choice of HRQOL instruments. Study Design and Setting: Systematic review of English language literature published between January 1985 and May 2014 identified through a database search of PubMed, Web of Science, Embase, and Ovid MEDLINE. HRQOL instruments were rated on methodological quality and overall levels of evidence using a Consensus-based Standards for the selection of health Measurement Instrument checklist. Results: Internal consistency and hypothesis testing were evaluated most frequently in 63 studies identified. The Functional Assessment of Cancer Therapy-Colorectal (FACT-C) was the most extensively evaluated. The highest number of positive ratings in the overall level of evidence was found in the CRC-specific quality of life questionnaire module (QLQ-CR38) in European Organization for Research and Treatment of Cancer (EORTC) module, followed by the Memorial Sloan Kettering Cancer Center Bowel instrument, FACT-C, and Quick-FLIC. The EORTC QLQ-CR38 had the most positive ratings on measurement property and was recommended. Conclusion: The EORTC QLQ-CR38 was recommended to assess HRQOL in patients with CRC, regardless of disease stage and primary tumor site.postprin

    Supersymmetric Higgs Yukawa Couplings to Bottom Quarks at next-to-next-to-leading Order

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    The effective bottom Yukawa couplings are analyzed for the minimal supersymmetric extension of the Standard Model at two-loop accuracy within SUSY-QCD. They include the resummation of the dominant corrections for large values of tg(beta). In particular the two-loop SUSY-QCD corrections to the leading SUSY-QCD and top-induced SUSY-electroweak contributions are addressed. The residual theoretical uncertainties range at the per-cent level.Comment: 25 pages, 9 figures, added comments and references, typos corrected, results unchanged, published versio
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