721 research outputs found
Prediction of anti-Alzheimerâs activity of flavonoids targeting acetylcholinesterase in silico
Introduction â 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 Alzheimerâs disease. Objective â 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 Alzheimerâs disease. Methodology â 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 Ellmanâs method. Results â 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 â Results indicated that flavonoids could be efficient inhibitors of AchE and thus, could be useful in the management of Alzheimerâs disease
Walker-Independent Features for Gait Recognition from Motion Capture Data
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 Fisherâs 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
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
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 production mechanisms at the LHC
In this note we demonstrate the use of top polarization in the study of 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 ) in the laboratory. The asymmetry is non-vanishing
even for a symmetric collider like the LHC, where a positive 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
couplings, to linear order. We study, for purposes of demonstration, the case
of a 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:
TeV and 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 GeV, being as high as for a smaller mass
of the of GeV and for the largest allowed coupling in the model, the
values being higher for the TeV option. These polarizations translate to a
deviation from the standard-model value of azimuthal asymmetry of up to about
() for () TeV LHC, whereas for the Tevatron, values as high as
are attained. For the TeV LHC with an integrated luminosity of 10
fb, these numbers translate into a sensitivity over a large
part of the range 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
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 Gâs approach
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 âwhite Britishâ 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 Gâs 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
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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