383 research outputs found

    Difference system for Selberg correlation integrals

    Full text link
    The Selberg correlation integrals are averages of the products s=1ml=1n(xszl)μs\prod_{s=1}^m\prod_{l=1}^n (x_s - z_l)^{\mu_s} with respect to the Selberg density. Our interest is in the case m=1m=1, μ1=μ\mu_1 = \mu, when this corresponds to the μ\mu-th moment of the corresponding characteristic polynomial. We give the explicit form of a (n+1)×(n+1)(n+1) \times (n+1) matrix linear difference system in the variable μ\mu which determines the average, and we give the Gauss decomposition of the corresponding (n+1)×(n+1)(n+1) \times (n+1) matrix. For μ\mu a positive integer the difference system can be used to efficiently compute the power series defined by this average.Comment: 21 page

    NuMI Beam Monitoring Simulation and Data Analysis Status and Progress

    Get PDF
    With the Main Injector Neutrino Oscillation Search (MINOS) experiment decommissioned, muon and hadron monitors became an important diagnostic tool for the NuMI Off-axis v Appearance (NOvA) experiment at Fermilab to monitor the Neutrinos at the Main Injector (NuMI) beam. The goal of this study is to maintain the quality of the monitor signals and to establish correlations with the neutrino beam profile. And we carry out a systematic study of the response of the muon monitors to the changes in the parameters of the proton beam and lattice parameters. We report here on the progress of the beam data analysis and comparison with the simulation results

    On the functions counting walks with small steps in the quarter plane

    Get PDF
    Models of spatially homogeneous walks in the quarter plane Z+2{\bf Z}_+^{2} with steps taken from a subset S\mathcal{S} of the set of jumps to the eight nearest neighbors are considered. The generating function (x,y,z)Q(x,y;z)(x,y,z)\mapsto Q(x,y;z) of the numbers q(i,j;n)q(i,j;n) of such walks starting at the origin and ending at (i,j)Z+2(i,j) \in {\bf Z}_+^{2} after nn steps is studied. For all non-singular models of walks, the functions xQ(x,0;z)x \mapsto Q(x,0;z) and yQ(0,y;z)y\mapsto Q(0,y;z) are continued as multi-valued functions on C{\bf C} having infinitely many meromorphic branches, of which the set of poles is identified. The nature of these functions is derived from this result: namely, for all the 51 walks which admit a certain infinite group of birational transformations of C2{\bf C}^2, the interval ]0,1/S[]0,1/|\mathcal{S}|[ of variation of zz splits into two dense subsets such that the functions xQ(x,0;z)x \mapsto Q(x,0;z) and yQ(0,y;z)y\mapsto Q(0,y;z) are shown to be holonomic for any zz from the one of them and non-holonomic for any zz from the other. This entails the non-holonomy of (x,y,z)Q(x,y;z)(x,y,z)\mapsto Q(x,y;z), and therefore proves a conjecture of Bousquet-M\'elou and Mishna.Comment: 40 pages, 17 figure

    Prospects for progress on health inequalities in England in the post-primary care trust era : professional views on challenges, risks and opportunities

    Get PDF
    Background - Addressing health inequalities remains a prominent policy objective of the current UK government, but current NHS reforms involve a significant shift in roles and responsibilities. Clinicians are now placed at the heart of healthcare commissioning through which significant inequalities in access, uptake and impact of healthcare services must be addressed. Questions arise as to whether these new arrangements will help or hinder progress on health inequalities. This paper explores the perspectives of experienced healthcare professionals working within the commissioning arena; many of whom are likely to remain key actors in this unfolding scenario. Methods - Semi-structured interviews were conducted with 42 professionals involved with health and social care commissioning at national and local levels. These included representatives from the Department of Health, Primary Care Trusts, Strategic Health Authorities, Local Authorities, and third sector organisations. Results - In general, respondents lamented the lack of progress on health inequalities during the PCT commissioning era, where strong policy had not resulted in measurable improvements. However, there was concern that GP-led commissioning will fare little better, particularly in a time of reduced spending. Specific concerns centred on: reduced commitment to a health inequalities agenda; inadequate skills and loss of expertise; and weakened partnership working and engagement. There were more mixed opinions as to whether GP commissioners would be better able than their predecessors to challenge large provider trusts and shift spend towards prevention and early intervention, and whether GPs’ clinical experience would support commissioning action on inequalities. Though largely pessimistic, respondents highlighted some opportunities, including the potential for greater accountability of healthcare commissioners to the public and more influential needs assessments via emergent Health & Wellbeing Boards. Conclusions - There is doubt about the ability of GP commissioners to take clearer action on health inequalities than PCTs have historically achieved. Key actors expect the contribution from commissioning to address health inequalities to become even more piecemeal in the new arrangements, as it will be dependent upon the interest and agency of particular individuals within the new commissioning groups to engage and influence a wider range of stakeholders.</p

    High-spin States in \u3csup\u3e191, 193\u3c/sup\u3eAu and \u3csup\u3e192\u3c/sup\u3ePt: Evidence for Oblate Deformation and Triaxial Shapes

    Get PDF
    High-spin states of 191, 193Au and 192Pt have been populated in the 186W(11B, xn) and 186W(11B, p4n) reactions, respectively, at a beam energy of 68 MeV and their γ decay was studied using the YRAST Ball detector array at the Wright Nuclear Structure Laboratory at Yale University. The level scheme of 193Au has been extended up to Iπ = 55/2+. New transitions were observed also in 191Au and 192Pt. Particle-plus-Triaxial-Rotor (PTR) and Total Routhian Surface (TRS) calculations were performed to determine the equilibrium deformations of the Au isotopes. The predictions for oblate deformations in these nuclei are in agreement with the experimental data. Development of nonaxial shapes is discussed within the framework of the PTR model

    Symphytum Species: A Comprehensive Review on Chemical Composition, Food Applications and Phytopharmacology

    Get PDF
    Symphytum species belongs to the Boraginaceae family and have been used for centuries for bone breakages, sprains and rheumatism, liver problems, gastritis, ulcers, skin problems, joint pain and contusions, wounds, gout, hematomas and thrombophlebitis. Considering the innumerable potentialities of the Symphytum species and their widespread use in the world, it is extremely important to provide data compiling the available literature to identify the areas of intense research and the main gaps in order to design future studies. The present review aims at summarizing the main data on the therapeutic indications of the Symphytum species based on the current evidence, also emphasizing data on both the e cacy and adverse e ects. The present review was carried out by consulting PubMed (Medline), Web of Science, Embase, Scopus, Cochrane Database, Science Direct and Google Scholar (as a search engine) databases to retrieve the most updated articles on this topic. All articles were carefully analyzed by the authors to assess their strengths and weaknesses, and to select the most useful ones for the purpose of review, prioritizing articles published from 1956 to 2018. The pharmacological e ects of the Symphytum species are attributed to several chemical compounds, among them allantoin, phenolic compounds, glycopeptides, polysaccharides and some toxic pyrrolizidine alkaloids. Not less important to highlight are the risks associated with its use. In fact, there is increasing consumption of over-the-counter drugs, which when associated with conventional drugs can cause serious and even fatal adverse events. Although clinical trials sustain the folk topical application of Symphytum species in musculoskeletal and blunt injuries, with minor adverse e ects, its antimicrobial potency was still poorly investigated. Further studies are needed to assess the antimicrobial spectrum of Symphytum species and to characterize the active molecules both in vitro and in vivo

    Fast construction of irreducible polynomials over finite fields

    Get PDF
    International audienceWe present a randomized algorithm that on input a finite field KK with qq elements and a positive integer dd outputs a degree dd irreducible polynomial in K[x]K[x]. The running time is d1+o(1)×(logq)5+o(1)d^{1+o(1)} \times (\log q)^{5+o(1)} elementary operations. The o(1)o(1) in d1+o(1)d^{1+o(1)} is a function of dd that tends to zero when dd tends to infinity. And the o(1)o(1) in (logq)5+o(1)(\log q)^{5+o(1)} is a function of qq that tends to zero when qq tends to infinity. In particular, the complexity is quasi-linear in the degree dd

    Solving Phase Retrieval with a Learned Reference

    Full text link
    Fourier phase retrieval is a classical problem that deals with the recovery of an image from the amplitude measurements of its Fourier coefficients. Conventional methods solve this problem via iterative (alternating) minimization by leveraging some prior knowledge about the structure of the unknown image. The inherent ambiguities about shift and flip in the Fourier measurements make this problem especially difficult; and most of the existing methods use several random restarts with different permutations. In this paper, we assume that a known (learned) reference is added to the signal before capturing the Fourier amplitude measurements. Our method is inspired by the principle of adding a reference signal in holography. To recover the signal, we implement an iterative phase retrieval method as an unrolled network. Then we use back propagation to learn the reference that provides us the best reconstruction for a fixed number of phase retrieval iterations. We performed a number of simulations on a variety of datasets under different conditions and found that our proposed method for phase retrieval via unrolled network and learned reference provides near-perfect recovery at fixed (small) computational cost. We compared our method with standard Fourier phase retrieval methods and observed significant performance enhancement using the learned reference.Comment: Accepted to ECCV 2020. Code is available at https://github.com/CSIPlab/learnPR_referenc

    Cerebral activations related to ballistic, stepwise interrupted and gradually modulated movements in parkinson patients

    Get PDF
    Patients with Parkinson's disease (PD) experience impaired initiation and inhibition of movements such as difficulty to start/stop walking. At single-joint level this is accompanied by reduced inhibition of antagonist muscle activity. While normal basal ganglia (BG) contributions to motor control include selecting appropriate muscles by inhibiting others, it is unclear how PD-related changes in BG function cause impaired movement initiation and inhibition at single-joint level. To further elucidate these changes we studied 4 right-hand movement tasks with fMRI, by dissociating activations related to abrupt movement initiation, inhibition and gradual movement modulation. Initiation and inhibition were inferred from ballistic and stepwise interrupted movement, respectively, while smooth wrist circumduction enabled the assessment of gradually modulated movement. Task-related activations were compared between PD patients (N = 12) and healthy subjects (N = 18). In healthy subjects, movement initiation was characterized by antero-ventral striatum, substantia nigra (SN) and premotor activations while inhibition was dominated by subthalamic nucleus (STN) and pallidal activations, in line with the known role of these areas in simple movement. Gradual movement mainly involved antero-dorsal putamen and pallidum. Compared to healthy subjects, patients showed reduced striatal/SN and increased pallidal activation for initiation, whereas for inhibition STN activation was reduced and striatal-thalamo-cortical activation increased. For gradual movement patients showed reduced pallidal and increased thalamo-cortical activation. We conclude that PD-related changes during movement initiation fit the (rather static) model of alterations in direct and indirect BG pathways. Reduced STN activation and regional cortical increased activation in PD during inhibition and gradual movement modulation are better explained by a dynamic model that also takes into account enhanced responsiveness to external stimuli in this disease and the effects of hyper-fluctuating cortical inputs to the striatum and STN in particular

    K(892)0K^{*}(892)^0 meson production in inelastic p+p interactions at 40 and 80  GeV  ⁣/ ⁣c\text{ GeV }\!/\!c beam momenta measured by NA61/SHINE at the CERN SPS

    Get PDF
    Measurements of K∗(892)0 resonance production via its K+π− decay mode in inelastic p+p collisions at beam momenta 40 and 80 GeV /c (sNN−−−−√=8.8 and 12.3 GeV ) are presented. The data were recorded by the NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The template method was used to extract the K∗(892)0 signal. Transverse momentum and rapidity spectra were obtained. The mean multiplicities of K∗(892)0 mesons were found to be (35.1±1.3(stat)±3.6(sys))⋅10−3 at 40 GeV /c and (58.3±1.9(stat)±4.9(sys))⋅10−3 at 80 GeV /c. The NA61/SHINE results are compared with the Epos1.99 and Hadron Resonance Gas models as well as with world data. The transverse mass spectra of K∗(892)0 mesons and other particles previously reported by NA61/SHINE were fitted within the Blast-Wave model. The transverse flow velocities are close to 0.1–0.2 of the speed of light and are significantly smaller than the ones determined in heavy nucleus-nucleus interactions at the same beam momenta
    corecore