1,979 research outputs found

    In Digital We Trust: The Computerisation of Retail Finance in Western Europe and North America

    Get PDF
    This paper tells of the contents of a forthcoming volume, which offers a new and original approach to the study of technological change in retail finance. Most business history studies of businesses for the last 50 years note the emergence of computers and computer applications, but they do not analyze their role in shaping business practices and organizations. In this book we look directly at the processes of mechanisation and computerisation of retail financial services, throughout the 20th Century while articulating an international comparison. We bring together young, well established and independent historians, who come from different traditions (that is, economic, business, accounting, geography and political histories as well as historians of technology). Contributors look at stand alone and comparative case studies from different parts of the world (namely Britain, Denmark, France, Germany, Netherlands, Spain, Sweden, Mexico and the USA). The outcome is a rich survey of the broad literature examining different aspects of the technological and business histories of retail financial markets from a variety of perspectives

    Magnon delocalization in ferromagnetic chains with long-range correlated disorder

    Full text link
    We study one-magnon excitations in a random ferromagnetic Heisenberg chain with long-range correlations in the coupling constant distribution. By employing an exact diagonalization procedure, we compute the localization length of all one-magnon states within the band of allowed energies EE. The random distribution of coupling constants was assumed to have a power spectrum decaying as S(k)1/kαS(k)\propto 1/k^{\alpha}. We found that for α<1\alpha < 1, one-magnon excitations remain exponentially localized with the localization length ξ\xi diverging as 1/E. For α=1\alpha = 1 a faster divergence of ξ\xi is obtained. For any α>1\alpha > 1, a phase of delocalized magnons emerges at the bottom of the band. We characterize the scaling behavior of the localization length on all regimes and relate it with the scaling properties of the long-range correlated exchange coupling distribution.Comment: 7 Pages, 5 figures, to appear in Phys. Rev.

    Immune Profiling of Peripheral Blood Mononuclear Cells at Pancreas Acute Rejection Episodes in Kidney-Pancreas Transplant Recipients

    Full text link
    Profiling of circulating immune cells provides valuable insight to the pathophysiology of acute rejection in organ transplantation. Herein we characterized the peripheral blood mononuclear cells in simultaneous kidney-pancreas transplant recipients. We conducted a retrospective analysis in a biopsy-matched cohort (n = 67) and compared patients with biopsy proven acute rejection (BPAR; 41%) to those without rejection (No-AR). We observed that CD3+ T cells, both CD8+ and CD4+, as well as CD19+ B cells were increased in patients with BPAR, particularly in biopsies performed in the early post-transplant period (<3 months). During this period immune subsets presented a good discriminative ability (CD4+ AUC 0.79; CD8+ AUC 0.80; B cells AUC 0.86; p < 0.05) and outperformed lipase (AUC 0.62; p = 0.12) for the diagnosis of acute rejection. We further evaluated whether this could be explained by differences in frequencies prior to transplantation. Patients presenting with early post-transplant rejection (<3 months) had a significant increase in T-cell frequencies pre-transplant, both CD4+ T cells and CD8+ T cells (p < 0.01), which were associated with a significant inferior rejection-free graft survival. T cell frequencies in peripheral blood correlated with pancreas acute rejection episodes, and variations prior to transplantation were associated with pancreas early acute rejection.Copyright © 2022 Rovira, Ramirez-Bajo, Bañón-Maneus, Hierro-Garcia, Lazo-Rodriguez, Piñeiro, Montagud-Marrahi, Cucchiari, Revuelta, Cuatrecasas, Campistol, Ricart, Diekmann, Garcia-Criado and Ventura-Aguiar

    The Dynamical Behaviour of Test Particles in a Quasi-Spherical Spacetime and the Physical Meaning of Superenergy

    Full text link
    We calculate the instantaneous proper radial acceleration of test particles (as measured by a locally defined Lorentzian observer) in a Weyl spacetime, close to the horizon. As expected from the Israel theorem, there appear some bifurcations with respect to the spherically symmetric case (Schwarzschild), which are explained in terms of the behaviour of the superenergy, bringing out the physical relevance of this quantity in the study of general relativistic systems.Comment: 14 pages, Latex. 4 figures. New references added. Typos corrected. To appear in Int. J. Theor. Phy

    Search for right-handed W bosons in top quark decay

    Full text link
    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

    Measurement of the Lifetime Difference in the B_s^0 System

    Get PDF
    We present a study of the decay B_s^0 -> J/psi phi We obtain the CP-odd fraction in the final state at time zero, R_perp = 0.16 +/- 0.10 (stat) +/- 0.02 (syst), the average lifetime of the (B_s, B_sbar) system, tau (B_s^0) =1.39^{+0.13}_{-0.16} (stat) ^{+0.01}_{-0.02} (syst) ps, and the relative width difference between the heavy and light mass eigenstates, Delta Gamma/Gamma = (Gamma_L - Gamma_H)/Gamma =0.24^{+0.28}_{-0.38} (stat) ^{+0.03}_{-0.04} (syst). With the additional constraint from the world average of the B_s^0$lifetime measurements using semileptonic decays, we find tau (B_s^0)= 1.39 +/- 0.06 ~ps and Delta Gamma/\Gamma = 0.25^{+0.14}_{-0.15}. For the ratio of the B_s^0 and B^0 lifetimes we obtain tau(B_s^0)/tau(B^0)} = 0.91 +/- 0.09 (stat) +/- 0.003 (syst).Comment: submitted to Phys. Rev. Lett. FERMILAB-PUB-05-324-

    A search for W bb and W Higgs production in ppbar collisions at sqrt(s)=1.96 TeV

    Get PDF
    We present a search for W b \bar{b} production in p \bar{p} collisions at sqrt{s}=1.96 TeV in events containing one electron, an imbalance in transverse momentum, and two b-tagged jets. Using 174 pb-1 of integrated luminosity accumulated by the D0 experiment at the Fermilab Tevatron collider, and the standard-model description of such events, we set a 95% C.L. upper limit on W b \bar{b}productionof6.6pbforbquarkswithtransversemomentapTb>20GeVandbbˉseparationinpseudorapidityazimuthspaceDeltaRbb>0.75.Restrictingthesearchtooptimizedbbˉmassintervalsprovidesupperlimitson production of 6.6 pb for b quarks with transverse momenta p_T^b > 20 GeV and b \bar{b} separation in pseudorapidity-azimuth space Delta R_bb > 0.75. Restricting the search to optimized b \bar{b} mass intervals provides upper limits on WHproductionof9.0 production of 9.0-12.2pb,forHiggsbosonmassesof10512.2 pb, for Higgs-boson masses of 105-$135 GeV.Comment: 7 pages, 4 figures, 1 table, submitted to Physical Review Letter

    Study of ZγZ\gamma events and limits on anomalous ZZγZZ\gamma and ZγγZ\gamma\gamma couplings in ppbar collisions at sqrt(s)=1.96sqrt(s) = 1.96 TeV

    Get PDF
    We present a measurement of the Z\gamma production cross section and limits on anomalous ZZ\gamma and Z\gamma\gamma couplings for form-factor scales of Lambda = 750 and 1000 GeV. The measurement is based on 138 (152) candidate events in the ee\gamma (\mu\mu\gamma) final state using 320 (290) pb^{-1} of ppbar collisions at \sqrt{s} = 1.96 TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are |h_{10,30}^{Z}|<0.23, |h_{20,40}^{Z}|<0.020, |h_{10,30}^{\gamma}|<0.23, and |h_{20,40}^{\gamma}|<0.019 for Lambda = 1000 GeV.Comment: submitted to Phys. Rev. Letter

    Measurement of the Ratio of B+ and B0 Meson Lifetimes

    Get PDF
    The ratio of B+ and B0 meson lifetimes was measured using data collected in 2002-2004 by the D0 experiment in Run II of the Fermilab Tevatron Collider. These mesons were reconstructed in B -> mu+ nu D*- X decays, which are dominated by B0, and B ->mu+ nu D0bar X decays, which are dominated by B+. The ratio of lifetimes is measured to be t+/t0 = 1.080 +- 0.016(stat) +- 0.014(syst).Comment: 7 pages, 2 figures, LaTeX, to be submitted to Physical Review Letter
    corecore