11,178 research outputs found

    Nonfactorization and the decays Ds+ϕπ+,ϕρ+D_s^+ \to \phi \pi^+, \phi \rho^+ and ϕl+νl\phi l^+ \nu_l

    Full text link
    In six chosen scenarios for the q2q^2 dependence of the form factors involved in Ds+ϕD_s^+ \rightarrow \phi transition, we have determined the allowed domain of x=A2(0)/A1(0)x = A_2(0) / A_1(0) and y=V(0)/A1(0)y = V(0)/A_1(0) from the experimentally measured ratios Rsl=Γ(Ds+ϕl+νl)/Γ(Ds+ϕπ+)R_{sl} = \Gamma(D_s^+ \rightarrow \phi l^+ \nu_l)/\Gamma(D_s^+ \rightarrow \phi \pi^+) and Rh=Γ(Ds+ϕρ+)/Γ(Ds+ϕπ+)R_h = \Gamma(D_s^+ \rightarrow \phi \rho^+)/\Gamma(D_s^+ \rightarrow \phi \pi^+) in a scheme that uses the Nc=3N_c =3 value of the phenomenological parameter a1a_1 and includes nonfactorized contribution. We find that the experimentally measured values of xx and yy from semileptonic decays of Ds+D_s^+ favor solutions which have significant nonfactorized contribution, and, in particular, RslR_{sl} favors solutions in scenarios where A1(q2)A_1(q^2) is either flat or decreasing with q2q^2.Comment: 15 pages, Latex, four figure (available on request)

    Virtual Data in CMS Analysis

    Full text link
    The use of virtual data for enhancing the collaboration between large groups of scientists is explored in several ways: - by defining ``virtual'' parameter spaces which can be searched and shared in an organized way by a collaboration of scientists in the course of their analysis; - by providing a mechanism to log the provenance of results and the ability to trace them back to the various stages in the analysis of real or simulated data; - by creating ``check points'' in the course of an analysis to permit collaborators to explore their own analysis branches by refining selections, improving the signal to background ratio, varying the estimation of parameters, etc.; - by facilitating the audit of an analysis and the reproduction of its results by a different group, or in a peer review context. We describe a prototype for the analysis of data from the CMS experiment based on the virtual data system Chimera and the object-oriented data analysis framework ROOT. The Chimera system is used to chain together several steps in the analysis process including the Monte Carlo generation of data, the simulation of detector response, the reconstruction of physics objects and their subsequent analysis, histogramming and visualization using the ROOT framework.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 9 pages, LaTeX, 7 eps figures. PSN TUAT010. V2 - references adde

    Effect of photoperiod and host distribution on the horizontal transmission of Isaria fumosorosea (Hypocreales: Cordycipitaceae) in greenhouse whitefly assessed using a novel model bioassay

    Get PDF
    A model bioassay was used to evaluate the epizootic potential and determine the horizontal transmission efficiency of Isaria fumosorosea Trinidadian strains against Trialeurodes vaporariorum pharate adults under optimum conditions (25±0.5°C, ~100% RH) at two different photoperiods. Untreated pharate adults were arranged on laminated graph paper at different distributions to simulate varying infestation levels on a leaf surface. Four potential hosts were located 7, 14 and 21 mm away from a central sporulating cadaver simulating high, medium and low infestation levels, respectively. Percent hosts colonized were recorded 7, 12, 14 and 21 days post-treatment during a 16- and 24-h photophase. After 21 days, mean percent hosts colonized at the highest, middle and lowest infestation levels were 93 and 100%, 22 and 58%, 25 and 39% under a 16- and 24-h photophase, respectively. From the results, it was concluded that the longer the photophase, the greater the percentage of hosts colonized, and as host distance increased from the central sporulating cadaver, colonization decreased. The use of this novel model bioassay technique is the first attempt to evaluate the epizootic potential and determine the horizontal transmission efficiency of I. fumosorosea Trinidadian strains under optimal environmental conditions at different photoperiods. This bioassay can be used to assess horizontal transmission efficiency for the selection of fungi being considered for commercial biopesticide development

    Shape sensing of variable stiffness soft robots using electrical impedance tomography

    Get PDF
    Soft robotic systems offer benefits over traditional rigid systems through reduced contact trauma with soft tissues and by enabling access through tortuous paths in minimally invasive surgery. However, the inherent deformability of soft robots places both a greater onus on accurate modelling of their shape, and greater challenges in realising intraoperative shape sensing. Herein we present a proprioceptive (self-sensing) soft actuator, with an electrically conductive working fluid. Electrical impedance measurements from up to six electrodes enabled tomographic reconstructions using Electrical Impedance Tomography (EIT). A new Frequency Division Multiplexed (FDM) EIT system was developed capable of measurements of 66 dB SNR with 20 ms temporal resolution. The concept was examined in two two-degree-of-freedom designs: a hydraulic hinged actuator and a pneumatic finger actuator with hydraulic beams. Both cases demonstrated that impedance measurements could be used to infer shape changes, and EIT images reconstructed during actuation showed distinct patterns with respect to each degree of freedom (DOF). Whilst there was some mechanical hysteresis observed, the repeatability of the measurements and resultant images was high. The results show the potential of FDM-EIT as a low-cost, low profile shape sensor in soft robots

    Chemical data assimilation estimates of continental U.S. ozone and nitrogen budgets during the Intercontinental Chemical Transport Experiment-North America

    Get PDF
    Global ozone analyses, based on assimilation of stratospheric profile and ozone column measurements, and NOy predictions from the Real-time Air Quality Modeling System (RAQMS) are used to estimate the ozone and NOy budget over the continental United States during the July-August 2004 Intercontinental Chemical Transport Experiment-North America (INTEX-A). Comparison with aircraft, satellite, surface, and ozonesonde measurements collected during INTEX-A show that RAQMS captures the main features of the global and continental U.S. distribution of tropospheric ozone, carbon monoxide, and NOy with reasonable fidelity. Assimilation of stratospheric profile and column ozone measurements is shown to have a positive impact on the RAQMS upper tropospheric/lower stratosphere ozone analyses, particularly during the period when SAGE III limb scattering measurements were available. Eulerian ozone and NOy budgets during INTEX-A show that the majority of the continental U.S. export occurs in the upper troposphere/lower stratosphere poleward of the tropopause break, a consequence of convergence of tropospheric and stratospheric air in this region. Continental U.S. photochemically produced ozone was found to be a minor component of the total ozone export, which was dominated by stratospheric ozone during INTEX-A. The unusually low photochemical ozone export is attributed to anomalously cold surface temperatures during the latter half of the INTEX-A mission, which resulted in net ozone loss during the first 2 weeks of August. Eulerian NOy budgets are shown to be very consistent with previously published estimates. The NOy export efficiency was estimated to be 24%, with NOx + PAN accounting for 54% of the total NOy export during INTEX-A. Copyright 2007 by the American Geophysical Union

    History of Regulations, Policy, and Research Related to Conflicts between Blackbirds and People

    Get PDF
    The United States and Canada have invested substantial resources over the past 60 years for developing methods to reduce blackbird (Icteridae) damage to agricultural crops, to manage large winter roosts that create nuisance and public health problems, and to mitigate conflicts with endangered species. It is an indication of the challenging nature of the conflicts with these abundant, highly mobile birds that we are still attempting to improve existing methods and develop new approaches to mitigate the problems. Scientists have tested chemical frightening agents and repellents, mechanical scare devices, bird-resistant sunflowers, decoy crops, habitat management, population management, and cultural modifications in cropping. Methods development proceeds within a framework of federal and state laws and agency policies. Here, we review key laws and policies that guide scientists focused on methods development, and we briefly recount the history of applied blackbird research in the United States and Canada
    corecore