225 research outputs found

    Inelastic nucleon contributions in (e,e)(e,e^\prime) nuclear response functions

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    We estimate the contribution of inelastic nucleon excitations to the (e,e)(e,e^\prime) inclusive cross section in the CEBAF kinematic range. Calculations are based upon parameterizations of the nucleon structure functions measured at SLAC. Nuclear binding effects are included in a vector-scalar field theory, and are assumed have a minimal effect on the nucleon excitation spectrum. We find that for q\lsim 1 GeV the elastic and inelastic nucleon contributions to the nuclear response functions are comparable, and can be separated, but with roughly a factor of two uncertainty in the latter from the extrapolation from data. In contrast, for q\rsim 2 GeV this uncertainty is greatly reduced but the elastic nucleon contribution is heavily dominated by the inelastic nucleon background.Comment: 20 pages, 7 figures available from the authors at Department of Physics and Astronomy, University of Rochester, Rochester NY 1462

    A sensorless initial rotor position's estimation for permanent magnet synchronous machines

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    Permanent magnet synchronous motors for the effective start require information about the initial position of a rotor. In this regard, most systems use position sensors, which substantially increase entirely a cost of an electrical drive [1-3]. The aim of this article is to develop a new method, allowing determining the absolute angular position of the permanent magnet synchronous motors' rotor [4,5]. With a certain voltage pulses applied to the motor, its stator is magnetized by currents leakage in the windings. This allows using a special algorithm to calculate the absolute position of the rotor without using any motor parameters [6]. Simulation results prove the simplicity and efficiency of this method for determining an initial position of the permanent magnet synchronous motors' rotor. Thus, this method can be widely used in the electrical industry

    Dependence of pp->pp pi0 near Threshold on the Spin of the Colliding Nucleons

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    A polarized internal atomic hydrogen target and a stored, polarized beam are used to measure the spin-dependent total cross section Delta_sigma_T/sigma_tot, as well as the polar integrals of the spin correlation coefficient combination A_xx-A_yy, and the analyzing power A_y for pp-> pp pi0 at four bombarding energies between 325 and 400 MeV. This experiment is made possible by the use of a cooled beam in a storage ring. The polarization observables are used to study the contribution from individual partial waves.Comment: 6 pages, 1 table, 4 figures, corrected equations 2 and

    Spin correlations in pppnπ+\vec{p}\vec{p}\to pn\pi^{+} pion production near threshold

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    A first measurement of longitudinal as well as transverse spin correlation coefficients for the reaction pppnπ+\vec{p}\vec{p}\to pn\pi^+ was made using a polarized proton target and a polarized proton beam. We report kinematically complete measurements for this reaction at 325, 350, 375 and 400 MeV beam energy. The spin correlation coefficients Axx+Ayy,AxxAyy,Azz,Axz,A_{xx}+A_{yy}, A_{xx}-A_{yy}, A_{zz}, A_{xz}, and the analyzing power Ay,A_{y}, as well as angular distributions for σ(θπ)\sigma(\theta_{\pi}) and the polarization observables Aij(θπ)A_{ij}(\theta_{\pi}) were extracted. Partial wave cross sections for dominant transition channels were obtained from a partial wave analysis that included the transitions with final state angular momenta of l1l\leq 1. The measurements of the pppnπ+{\vec{p}\vec{p}\to pn\pi^{+}} polarization observables are compared with the predictions from the J\"ulich meson exchange model. The agreement is very good at 325 MeV, but it deteriorates increasingly for the higher energies. At all energies agreement with the model is better than for the reaction ppppπ0{\vec{p}\vec{p}\to pp\pi^{0}}.Comment: Preprint, 21 pp, submitted to Phys. Rev. C. Keywords: Mesons, Polarization, Spin Correlations, Few body system

    Effect of Specific Immunoglobulin E Response and Comorbidities on Effectiveness of MP-AzeFlu in a Real-Life Study

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    Acknowledgements: We would like to thank the subjects who participated in the trial. Funding Sources: This study was supported by MEDA Pharma GmbH & Co. KG (a Mylan Company), Bad Homburg, Germany. Technical, editorial, and medical writing assistance were provided under the direction of the authors by Strategix, an affiliate of The Lynx Group, LLC. This assistance was supported by MEDA Pharma GmbH & Co. KG (a Mylan Company).Peer reviewedPublisher PD

    The Chicken Yolk Sac IgY Receptor, a Mammalian Mannose Receptor Family Member, Transcytoses IgY across Polarized Epithelial Cells

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    In mammals the transfer of passive immunity from mother to young is mediated by the MHC-related receptor FcRn, which transports maternal IgG across epithelial cell barriers. In birds, maternal IgY in egg yolk is transferred across the yolk sac to passively immunize chicks during gestation and early independent life. The chicken yolk sac IgY receptor (FcRY) is the ortholog of the mammalian phospholipase A2 receptor, a mannose receptor family member, rather than an FcRn or MHC homolog. FcRn and FcRY both exhibit ligand binding at the acidic pH of endosomes and ligand release at the slightly basic pH of blood. Here we show that FcRY expressed in polarized mammalian epithelial cells functioned in endocytosis, bidirectional transcytosis, and recycling of chicken FcY/IgY. Confocal immunofluorescence studies demonstrated that IgY binding and endocytosis occurred at acidic but not basic pH, mimicking pH-dependent uptake of IgG by FcRn. Colocalization studies showed FcRY-mediated internalization via clathrin-coated pits and transport involving early and recycling endosomes. Disruption of microtubules partially inhibited apical-to-basolateral and basolateral-to-apical transcytosis, but not recycling, suggesting the use of different trafficking machinery. Our results represent the first cell biological evidence of functional equivalence between FcRY and FcRn and provide an intriguing example of how evolution can give rise to systems in which similar biological requirements in different species are satisfied utilizing distinct protein folds

    Dynamical coupled channel calculation of pion and omega meson production

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    A dynamical coupled channel approach is used to study π\pi and ω\omega--meson production induced by pions and photons scattering from the proton. Six intermediate channels including πN\pi N, ηN\eta N, πΔ\pi\Delta, σN\sigma N, ρN\rho N and ωN\omega N are employed to describe unpolarized and polarized data. Bare parameters in an effective hadronic Lagrangian are determined in a fit to data for πNπN\pi N \to \pi N, γNπN\gamma N \to \pi N, πpωn\pi^- p \to \omega n, and γpωp\gamma p \to \omega p reactions at center-of-mass energies from threshold to W<2.0W < 2.0 GeV. The TT matrix determined in these fits is used to calculate the photon beam asymmetry for ω\omega-meson production and the ωNωN\omega N \to\omega N total cross section and ωN\omega N scattering lengths.Comment: 26 pages, 18 figures, submitted to Phys. Rev. C; corrected typos, added references, minor revisions, same results/fig

    Pion Excess, Nuclear Correlations, and the Interpretation of (p,n\vec p, \vec n) Spin Transfer Experiments

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    Conventional theories of nuclear interactions predict a net increase in the distribution of virtual pions in nuclei relative to free nucleons. Analysis of data from several nuclear experiments has led to claims of evidence against such a pion excess. These conclusions are usually based on a collective theory (RPA) of the pions, which may be inadequate. The issue is the energy dependence of the nuclear response, which differs for theories with strong NN correlations from the RPA predictions. In the present paper, information about the energy dependence is extracted from sum rules, which are calculated for such a correlated, noncollective nuclear theory. The results lead to much reduced sensitivity of nuclear reactions to the correlations that are responsible for the pion excess. The primary example is (p,n)(\vec p,\vec n) spin transfer, for which the expected effects are found to be smaller than the experimental uncertainties. The analysis has consequences for Deep Inelastic Scattering (DIS) experiments as well.Comment: 16 pages, LaTeX, no figures, submitted to Phys. Rev.

    Distorted wave impulse approximation analysis for spin observables in nucleon quasi-elastic scattering and enhancement of the spin-longitudinal response

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    We present a formalism of distorted wave impulse approximation (DWIA) for analyzing spin observables in nucleon inelastic and charge exchange reactions leading to the continuum. It utilizes response functions calculated by the continuum random phase approximation (RPA), which include the effective mass, the spreading widths and the \Delta degrees of freedom. The Fermi motion is treated by the optimal factorization, and the non-locality of the nucleon-nucleon t-matrix by an averaged reaction plane approximation. By using the formalism we calculated the spin-longitudinal and the spin-transverse cross sections, ID_q and ID_p, of 12C, 40Ca (\vec{p},\vec{n}) at 494 and 346 MeV. The calculation reasonably reproduced the observed ID_q, which is consistent with the predicted enhancement of the spin-longitudinal response function R_L. However, the observed ID_p is much larger than the calculated one, which was consistent with neither the predicted quenching nor the spin-transverse response function R_T obtained by the (e,e') scattering. The Landau-Migdal parameter g'_N\Delta for the N\Delta transition interaction and the effective mass at the nuclear center m^*(r=0) are treated as adjustable parameters. The present analysis indicates that the smaller g'_{N\Delta}(\approx 0.3) and m^*(0) \approx 0.7 m are preferable. We also investigate the validity of the plane wave impulse approximation (PWIA) with the effective nucleon number approximation for the absorption, by means of which R_L and R_T have conventionally been extracted.Comment: RevTex 3, 29 pages, 2 tables, 8 figure
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