721 research outputs found

    Prediction of anti-Alzheimer’s activity of flavonoids targeting acetylcholinesterase in silico

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    Introduction – Prenylated and pyrano-flavonoids of the genus Artocarpus J. R. Forster & G. Forster are well known for their acetylcholinesterase (AchE) inhibitory, anticholinergic, antiinflammatory, antimicrobial, antioxidant, antiproliferative and tyrosinase inhibitory activities. Some of these compounds have also been shown to be effective against Alzheimer’s disease. Objective – The aim of the in silico study was to establish protocols to predict the most effective flavonoid from prenylated and pyrano-flavonoid classes for AchE inhibition linking to the potential treatment of Alzheimer’s disease. Methodology – Three flavonoids isolated from Artocarpus anisophyllus Miq. were selected for the study. With these compounds, Lipinski filter, ADME/Tox screening, molecular docking and QSAR were performed in silico. In vitro activity was evaluated by bioactivity staining based on the Ellman’s method. Results – In the Lipinski filter and ADME/Tox screening, all test compounds produced positive results, but in the target fishing, only one flavonoid could successfully target AchE. Molecular docking was performed on this flavonoid, and this compound gained the score as -13.5762. From the QSAR analysis the IC50 was found to be 1659.59 nM. Again, 100 derivatives were generated from the parent compound and docking was performed. The derivative number 20 was the best scorer i.e., -31.6392 and IC50 was predicted as 6.025 nM. Conclusion – Results indicated that flavonoids could be efficient inhibitors of AchE and thus, could be useful in the management of Alzheimer’s disease

    Walker-Independent Features for Gait Recognition from Motion Capture Data

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    MoCap-based human identification, as a pattern recognition discipline, can be optimized using a machine learning approach. Yet in some applications such as video surveillance new identities can appear on the fly and labeled data for all encountered people may not always be available. This work introduces the concept of learning walker-independent gait features directly from raw joint coordinates by a modification of the Fisher’s Linear Discriminant Analysis with Maximum Margin Criterion. Our new approach shows not only that these features can discriminate different people than who they are learned on, but also that the number of learning identities can be much smaller than the number of walkers encountered in the real operation

    Probing anomalous tbW couplings in single-top production using top polarization at the Large Hadron Collider

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    We study the sensitivity of the Large Hadron Collider (LHC) to anomalous tbW couplings in single-top production in association with a W^- boson followed by semileptonic decay of the top. We calculate top polarization and the effects of these anomalous couplings to it at two centre-of-mass (cm) energies of 7 TeV and 14 TeV. As a measure of top polarization, we look at various laboratory frame distributions of its decay products, viz., lepton angular and energy distributions and b-quark angular distributions, without requiring reconstruction of the rest frame of the top, and study the effect of anomalous couplings on these distributions. We construct certain asymmetries to study the sensitivity of these distributions to anomalous tbW couplings. We find that 1\sigma limits on real and imaginary parts of the dominant anomalous coupling Ref_{2R} which may be obtained by utilizing these asymmetries at the LHC with cm energy of 14 TeV and an integrated luminosity of 10 fb^{-1} will be significantly better than the expectations from direct measurements of cross sections and some other variables at the LHC and over an order of magnitude better than the indirect limits.Comment: 25 pages, 34 figure

    Higgs production as a probe of anomalous top couplings

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    The LHC may be currently seeing the first hints of the Higgs boson. The dominant production mode for the Higgs at the LHC involves a top-quark loop. An accurate measurement of Higgs production cross-sections and decay widths can thus be used to obtain limits on anomalous top couplings. We find that such an exercise could potentially yield constraints that are stronger than those derived from low-energy observables as well as direct bounds expected from the top pair-production process.Comment: Version published in JHE

    On measurement of top polarization as a probe of ttˉt \bar t production mechanisms at the LHC

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    In this note we demonstrate the use of top polarization in the study of ttˉt \bar t resonances at the LHC, in the possible case where the dynamics implies a non-zero top polarization. As a probe of top polarization we construct an asymmetry in the decay-lepton azimuthal angle distribution (corresponding to the sign of cos⁡ϕℓ\cos\phi_\ell) in the laboratory. The asymmetry is non-vanishing even for a symmetric collider like the LHC, where a positive zz axis is not uniquely defined. The angular distribution of the leptons has the advantage of being a faithful top-spin analyzer, unaffected by possible anomalous tbWtbW couplings, to linear order. We study, for purposes of demonstration, the case of a Z′Z' as might exist in the little Higgs models. We identify kinematic cuts which ensure that our asymmetry reflects the polarization in sign and magnitude. We investigate possibilities at the LHC with two energy options: s=14\sqrt{s} = 14 TeV and s=7\sqrt{s} = 7 TeV, as well as at the Tevatron. At the LHC the model predicts net top quark polarization of the order of a few per cent for MZ′≃1200M_{Z'} \simeq 1200 GeV, being as high as 1010 % for a smaller mass of the Z′Z' of 700700 GeV and for the largest allowed coupling in the model, the values being higher for the 77 TeV option. These polarizations translate to a deviation from the standard-model value of azimuthal asymmetry of up to about 44% (77%) for 1414 (77) TeV LHC, whereas for the Tevatron, values as high as 1212% are attained. For the 1414 TeV LHC with an integrated luminosity of 10 fb−1^{-1}, these numbers translate into a 3σ3 \sigma sensitivity over a large part of the range 500≲MZ′≲1500500 \lesssim M_{Z'} \lesssim 1500 GeV.Comment: 28 page, LaTeX, requires JHEP style file, 12 figures. Typos corrected and references adde

    Flavour Structure of R-violating Neutralino Decays at the LHC

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    We study signatures of R-parity violation in the production of supersymmetric particles at the LHC, and the subsequent decay of the lightest neutralino being the end product of a supersymmetric cascade decay. In doing so, we pay particular attention to the possible flavour structure of the operators, and how one may discriminate between different possibilities. A neutralino LSP would couple to all quarks and leptons and a comparative study of its decays provides an optimal channel for the simultaneous study of all 45 R-violating operators. By studying the expected signals from all these operators, we demonstrate the ability to understand whether more than one coupling dominates, and to map the experimental signatures to operator hierarchies that can then be compared against theoretical models of flavour. Detailed comparisons with backgrounds, including those from MSSM cascade decays are made, using the PYTHIA event simulator.Comment: 47 pages, 22 figures; v2 matches JHEP versio

    Improving prevention, monitoring and management of diabetes among ethnic minorities: contextualizing the six G’s approach

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    Objective: People from Black, Asian and Minority Ethnic (BAME) groups are known to have an increased risk of devel-oping diabetes and face greater barriers to accessing healthcare resources compared to their ‘white British’ counter-parts. The extent of these barriers varies by demographics and different socioeconomic circumstances that people find themselves in. The purpose of this paper is to present and discuss a new framework to understand, disentangle and tackle these barriers so that improvements in the effectiveness of diabetes interventions for BAME communities can be achieved. Results: The main mediators of lifestyle behavioural change are gender, generation, geography, genes, God/religion, and gaps in knowledge and economic resources. Dietary and cultural practices of these individuals significantly vary according to gender, generation, geographical origin and religion. Recognition of these factors is essential in increas-ing knowledge of healthy eating, engagement in physical activity and utilisation of healthcare services. Use of the six G’s framework alongside a community centred approach is crucial in developing and implementing culturally sensi-tive interventions for diabetes prevention and management in BAME communities. This could improve their health outcomes and overall wellbeing

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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