945 research outputs found

    Pronoun in Abel Matthieu’s linguistic concept (1520? - 1572?)

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    The aim of the article is to describe the system of pronouns in the linguistic concept of Abel Matthieu (1520? - 1572?), a French humanist, legal adviser and author of the treatise "Devis de la langue francoyse" (1559, 1560, 1572

    Unrolled three-operator splitting for parameter-map learning in Low Dose X-ray CT reconstruction

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    We propose a method for fast and automatic estimation of spatially dependent regularization maps for total variation-based (TV) tomography reconstruction. The estimation is based on two distinct sub-networks, with the first sub-network estimating the regularization parameter-map from the input data while the second one unrolling T iterations of the Primal-Dual Three-Operator Splitting (PD3O) algorithm. The latter approximately solves the corresponding TV-minimization problem incorporating the previously estimated regularization parameter-map. The overall network is then trained end-to-end in a supervised learning fashion using pairs of clean-corrupted data but crucially without the need of having access to labels for the optimal regularization parameter-maps

    Learning Regularization Parameter-Maps for Variational Image Reconstruction Using Deep Neural Networks and Algorithm Unrolling

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    We introduce a method for the fast estimation of data-adapted, spatially and temporally dependent regularization parameter-maps for variational image reconstruction, focusing on total variation (TV) minimization. The proposed approach is inspired by recent developments in algorithm unrolling using deep neural networks (NNs) and relies on two distinct subnetworks. The first subnetwork estimates the regularization parameter-map from the input data. The second subnetwork unrolls iterations of an iterative algorithm which approximately solves the corresponding TV-minimization problem incorporating the previously estimated regularization parameter-map. The overall network is then trained end-to-end in a supervised learning fashion using pairs of clean and corrupted data but crucially without the need for access to labels for the optimal regularization parameter-maps. We first prove consistency of the unrolled scheme by showing that the unrolled minimizing energy functional used for the supervised learning -converges, as tends to infinity, to the corresponding functional that incorporates the exact solution map of the TV-minimization problem. Then, we apply and evaluate the proposed method on a variety of large-scale and dynamic imaging problems with retrospectively simulated measurement data for which the automatic computation of such regularization parameters has been so far challenging using the state-of-the-art methods: a 2D dynamic cardiac magnetic resonance imaging (MRI) reconstruction problem, a quantitative brain MRI reconstruction problem, a low-dose computed tomography problem, and a dynamic image denoising problem. The proposed method consistently improves the TV reconstructions using scalar regularization parameters, and the obtained regularization parameter-maps adapt well to imaging problems and data by leading to the preservation of detailed features. Although the choice of the regularization parameter-maps is data-driven and based on NNs, the subsequent reconstruction algorithm is interpretable since it inherits the properties (e.g., convergence guarantees) of the iterative reconstruction method from which the network is implicitly defined

    Prospects of combined antihypertensive-psychocorrective therapy in women with arterial hypertension and anxiety-depressive disorders: clinical randomized placebo uncontrolled trial

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    Background. Anxiety-depressive disorders (ADD) afflict almost half of patients with arterial hypertension (AH). AH aggravation by psychoemotional disorders causes a more severe illness and rapid target organ injury, particularly, the increased arterial stiffness and central aortic pressure (CAP). However, the prospects of combined antihypertensive-antidepressant treatments in AH-ADD patients remain largely unexplored.Objectives. The effect assessment in combined antihypertensive-psychocorrective therapy on circadian blood pressure (BP), vascular stiffness and CAP, anxiety and depression in women with AH and ADD.Methods. The study enrolled 60 AH-ADD women randomised between two cohorts. Cohort 1 received a fixed combination of valsartan and hydrochlorothiazide, bisoprolol and sertraline antidepressant; cohort 2 only had same combined AH therapy. Past 24 weeks of trial, all patients had a general clinical examination and daily blood pressure monitoring (DBPM) with BpLab Vasotens (Petr Telegin Ltd., Russia) and control of daily BP, CAP and vascular stiffness. The psychometric HADS and CES-D scales were used along with psychiatric counselling.Results. Past four weeks of treatment, the target blood pressure (TBP) was revealed in 60 and 36.7% patients, and in 90 and 66.6% — past eight weeks in cohorts 1 and 2, respectively. Cohort 1 vs. 2 required a lower valsartan dose to attain TBP. Past six months, both cohorts showed improved main DBPM values reflecting vascular stiffness and CAP. However, a statistical decrease in nocturnal central and peripheral BP, as well as improved BP variability and vascular stiffness were registered at antidepressant use. A normalised daily BP profile was significantly more frequent in cohort 1. In addition, sertraline had a significant ADD-reductive impact.Conclusion. An antidepressant-combined conventional AH therapy in AH-ADD women facilitated a faster TBP achievement at lower AH agent doses and the significantly improved DBPM (nocturnal specifically), arterial stiffness and CAP values. A sertraline treatment improved the psychoemotional patient state

    GEANT4 : a simulation toolkit

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    Abstract Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics. PACS: 07.05.Tp; 13; 2

    Search for R-parity Violating Supersymmetry in Dimuon and Four-Jets Channel

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    We present results of a search for R-parity-violating decay of the neutralino chi_1^0, taken to be the Lightest Supersymmetric Particle. It is assumed that this decay proceeds through one of the lepton-number violating couplings lambda-prime_2jk (j=1,2; k=1,2,3). This search is based on 77.5 pb-1 of data, collected by the D0 experiment at the Fermilab Tevatron in ppbar collisions at a center of mass energy of 1.8 TeV in 1992-1995.Comment: 10 pages, 3 figure

    Measurement of Semileptonic Branching Fractions of B Mesons to Narrow D** States

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    Using the data accumulated in 2002-2004 with the DO detector in proton-antiproton collisions at the Fermilab Tevatron collider with centre-of-mass energy 1.96 TeV, the branching fractions of the decays B -> \bar{D}_1^0(2420) \mu^+ \nu_\mu X and B -> \bar{D}_2^{*0}(2460) \mu^+ \nu_\mu X and their ratio have been measured: BR(\bar{b}->B) \cdot BR(B-> \bar{D}_1^0 \mu^+ \nu_\mu X) \cdot BR(\bar{D}_1^0 -> D*- pi+) = (0.087+-0.007(stat)+-0.014(syst))%; BR(\bar{b}->B)\cdot BR(B->D_2^{*0} \mu^+ \nu_\mu X) \cdot BR(\bar{D}_2^{*0} -> D*- \pi^+) = (0.035+-0.007(stat)+-0.008(syst))%; and (BR(B -> \bar{D}_2^{*0} \mu^+ \nu_\mu X)BR(D2*0->D*- pi+)) / (BR(B -> \bar{D}_1^{0} \mu^+ \nu_\mu X)\cdot BR(\bar{D}_1^{0}->D*- \pi^+)) = 0.39+-0.09(stat)+-0.12(syst), where the charge conjugated states are always implied.Comment: submitted to Phys. Rev. Let

    Search for right-handed W bosons in top quark decay

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    We present a measurement of the fraction f+ of right-handed W bosons produced in top quark decays, based on a candidate sample of ttˉt\bar{t} events in the lepton+jets decay mode. These data correspond to an integrated luminosity of 230pb^-1, collected by the DO detector at the Fermilab Tevatron ppˉp\bar{p} Collider at sqrt(s)=1.96 TeV. We use a constrained fit to reconstruct the kinematics of the ttˉt\bar{t} and decay products, which allows for the measurement of the leptonic decay angle θ\theta^* for each event. By comparing the cosθ\cos\theta^* distribution from the data with those for the expected background and signal for various values of f+, we find f+=0.00+-0.13(stat)+-0.07(syst). This measurement is consistent with the standard model prediction of f+=3.6x10^-4.Comment: Submitted to Physical Review D Rapid Communications 7 pages, 3 figure
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