154 research outputs found
Semileptonic decays in Lattice QCD : a feasibility study and first results
We compute the decays and with finite
masses for the and quarks. We first discuss the spectral properties of
both the meson as a function of its momentum and of the and
at rest. We compute the theoretical formulae leading to the decay
amplitudes from the three-point and two-point correlators. We then compute the
amplitudes at zero recoil of which turns out not to be
vanishing contrary to what happens in the heavy quark limit. This opens a
possibility to get a better agreement with experiment. To improve the continuum
limit we have added a set of data with smaller lattice spacing. The vanishes at zero recoil and we show a convincing signal but only
slightly more than 1 sigma from 0. In order to reach quantitatively significant
results, we plan to fully exploit smaller lattice spacings as well as another
lattice regularization.Comment: 31 pages with 15 figures ; sections 5 and 6 revised and update
Unknown Health States Recognition With Collective Decision Based Deep Learning Networks In Predictive Maintenance Applications
At present, decision making solutions developed based on deep learning (DL)
models have received extensive attention in predictive maintenance (PM)
applications along with the rapid improvement of computing power. Relying on
the superior properties of shared weights and spatial pooling, Convolutional
Neural Network (CNN) can learn effective representations of health states from
industrial data. Many developed CNN-based schemes, such as advanced CNNs that
introduce residual learning and multi-scale learning, have shown good
performance in health state recognition tasks under the assumption that all the
classes are known. However, these schemes have no ability to deal with new
abnormal samples that belong to state classes not part of the training set. In
this paper, a collective decision framework for different CNNs is proposed. It
is based on a One-vs-Rest network (OVRN) to simultaneously achieve
classification of known and unknown health states. OVRN learn state-specific
discriminative features and enhance the ability to reject new abnormal samples
incorporated to different CNNs. According to the validation results on the
public dataset of Tennessee Eastman Process (TEP), the proposed CNN-based
decision schemes incorporating OVRN have outstanding recognition ability for
samples of unknown heath states, while maintaining satisfactory accuracy on
known states. The results show that the new DL framework outperforms
conventional CNNs, and the one based on residual and multi-scale learning has
the best overall performance
Determination of the moments of the proton charge density
A global analysis of proton electric form factor experimental data from
Rosenbluth separation and low squared four-momentum transfer experiments is
discussed for the evaluation of the spatial moments of the proton charge
density based on the recently published integral method \cite{Hob20}. Specific
attention is paid to the evaluation of the systematic errors of the method,
particularly the sensitivity to the choice of the mathematical expression of
the form factor fitting function. Within this comprehensive analysis of proton
electric form factor data, the moments of the proton charge density are
determined for integer order moments, particularly: =0.682(02)(11)~fm, =0.797(10)(58)~fm, and =1.02(05)(31)~fm. This analysis leads to the
proton charge radius 0.8459(12)(76)~fm once relativistic
effects are taken into account.Comment: 10 pages, 3 figure
Beam Charge Asymmetries for Deeply Virtual Compton Scattering on the Proton at CLAS12
The parameterization of the nucleon structure through Generalized Parton
Distributions (GPDs) shed a new light on the nucleon internal dynamics. For its
direct interpretation, Deeply Virtual Compton Scattering (DVCS) is the golden
channel for GPDs investigation. The DVCS process interferes with the
Bethe-Heitler (BH) mechanism to constitute the leading order amplitude of the
process. The study of the reaction with polarized
positron and electron beams gives a complete set of unique observables to
unravel the different contributions to the cross section. This
separates the different reaction amplitudes, providing a direct access to their
real and imaginary parts which procures crucial constraints on the model
dependences and associated systematic uncertainties on GPDs extraction. The
real part of the BH-DVCS interference amplitude is particularly sensitive to
the -term which parameterizes the Gravitational Form Factors of the nucleon.
The separation of the imaginary parts of the interference and DVCS amplitudes
provides insights on possible higher-twist effects. We propose to measure the
unpolarized and polarized Beam Charge Asymmetries (BCAs) of the process on an unpolarized hydrogen target with {\tt
CLAS12}, using polarized positron and electron beams at 10.6~GeV. The azimuthal
and -dependences of the unpolarized and polarized BCAs will be measured over
a large phase space using a 100 day run with a luminosity of
0.66cms.Comment: Proposal to the Jefferson Lab Program Advisory Committee (PAC51
Evaluation of the genotoxic and antigenotoxic potential of Melissa officinalis in mice
Melissa officinalis (L.) (Lamiaceae), a plant known as the lemon balm, is native to the east Mediterranean region and west Asia. Also found in tropical countries, such as Brazil, where it is popularly known as âerva-cidreiraâ or âmelissaâ, it is widely used in aqueous- or alcoholic-extract form in the treatment of various disorders. The aim was to investigate in vivo its antigenotoxicity and antimutagenicity, as well as its genotoxic/mutagenic potential through comet and micronucleus assaying. CF-1 male mice were treated with ethanolic (Mo-EE) (250 or 500 mg/kg) or aqueous (Mo-AE) (100 mg/kg) solutions of an M. officinalis extract for 2 weeks, prior to treatment with saline or Methyl methanesulfonate (MMS) doses by intraperitoneal injection. Irrespective of the doses, no genotoxic or mutagenic effects were observed in blood and bone-marrow samples. Although Mo-EE exerted an antigenotoxic effect on the blood cells of mice treated with the alkylating agent (MMS) in all the doses, this was not so with Mo-AE. Micronucleus testing revealed the protector effect of Mo-EE, but only when administered at the highest dose. The implication that an ethanolic extract of M. officinalis has antigenotoxic/antimutagenic properties is an indication of its medicinal relevance
Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study
Background
Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study.
Methods
We analysed cross-sectional data from 28â823 adults (â„40â
years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1â
s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income.
Results
Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for â„20â
years were more likely to have chronic cough (OR 1.52, 95% CI 1.19â1.94), wheeze (OR 1.37, 95% CI 1.16â1.63) and dyspnoea (OR 1.83, 95% CI 1.53â2.20), but not lower FVC (ÎČ=0.02â
L, 95% CI â0.02â0.06â
L) or lower FEV1/FVC (ÎČ=0.04%, 95% CI â0.49â0.58%). Some findings differed by sex and gross national income.
Conclusion
At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio
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