1,053 research outputs found

    Measurement of the running b-quark mass using e+ebbˉge^+e^- \to b\bar{b}g events

    Full text link
    We have studied the determination of the running b-quark mass, mb(MZ)m_b(M_Z), using Z0Z^0 decays into 3 or more hadronic jets. We calculated the ratio of 3\geq3-jet fractions in e+ebbˉe^+e^-\to b\bar{b} vs. e+eqlqlˉe^+e^-\to q_l\bar{q_l} (qlq_l = u or d or s) events at next-to-leading order in perturbative QCD using six different infra-red- and collinear-safe jet-finding algorithms. We compared with corresponding measurements from the SLD Collaboration and found a significant algorithm-dependence of the fitted mb(MZ)m_b(M_Z) value. Our best estimate, taking correlations into account, is mb(MZ)=2.56±0.27(stat.)0.38+0.28(syst.)1.48+0.49(theor.)GeV/c2m_b(M_Z) = 2.56 \pm 0.27 (stat.) ^{+0.28}_{-0.38} (syst.) ^{+0.49}_{-1.48} (theor.) GeV/c^2.Comment: 22 pages (LaTeX), 1 Postscript figure. Version to appear in Phys. Lett. B. Several clarifying remarks added in the text, typos corrected, and theoretical results for very small masses added in the figur

    A contribution to the conceptualisation of quality in impact assessment

    Get PDF
    Quality is much sought after in, and a basic foundation for, good impact assessment (IA). However, the term is rarely defined, has an uncertain relationship with IA effectiveness, and it means different things to different stakeholders, which can lead to debates over the legitimacy associated with an IA process. Thus, IA quality needs conceptualising to position research and practice within broader understandings. This paper contributes to this conceptualisation by identifying nine dimensions of quality through a process of literature review drawing on three fields of study in which quality and quality management have already been debated and conceptualised: education; health care; and business. This approach sidesteps the plural views on quality existing within the field of IA itself which might otherwise bias the identification of quality dimensions. We therefore propose that the dimensions of IA quality are: Efficiency; Optimacy; Conformance; Legitimacy; Equity; Capacity Maintenance; Transformative Capacity; and Quality Management. A literature review of IA research and practice confirms the relevance of the identified quality dimensions to IA. We identify, to an extent, the relationship between quality and effectiveness. Quality aligns with procedural and transactive effectiveness, partly aligns with normative effectiveness and is distinct from, but helps to deliver, substantive effectiveness

    Parallel multicentre randomised trial of a clinical trial question prompt list in patients considering participation in phase 3 cancer treatment trials

    Get PDF
    Accepted 9 February 2017Objective: To evaluate the effect of a clinical trial question prompt list in patients considering enrolment in cancer treatment trials. Setting: Tertiary cancer referral hospitals in three state capital cities in Australia. Participants: 88 patients with cancer attending three cancer centres in Australia, who were considering enrolment in phase 3 treatment trials, were invited to enrol in an unblinded randomised trial of provision of a clinical trial question prompt list (QPL) before consenting to enrol in the treatment trial. Interventions: We developed and pilot tested a targeted QPL for patients with cancer considering clinical trial participation (the clinical trial QPL). Consenting patients were randomised to receive the clinical trial QPL or not before further discussion with their oncologist and/or trial nurse about the treatment trial. Primary and secondary outcomes: Questionnaires were completed at baseline and within 3â €..weeks of deciding on treatment trial participation. Main outcome measure: scores on the Quality of Informed Consent questionnaire (QuIC). Results: 88 patients of 130 sought for the study were enrolled (43 males), and 45 received the clinical trial QPL. 49% of trials were chemotherapy interventions for patients with advanced disease, 35% and 16% were surgical adjuvant and radiation adjuvant trials respectively. 70 patients completed all relevant questionnaires. 28 of 43 patients in the control arm compared with 39 of 45 patients receiving the clinical trial QPL completed the QuIC (p=0.0124). There were no significant differences in the QuIC scores between the randomised groups (QuIC part A p=0.08 and QuIC part B p=0.92). There were no differences in patient satisfaction with decisions or in anxiety levels between the randomised groups. Conclusions: Use of a question prompt list did not significantly change the QuIC scores in this randomised trial. ANZCTR 12606000214538 prospectively registered 31/5/2006. Trial registration number: Results, ACTRN12606000214538.Martin H N Tattersall, Michael Jefford, Andrew Martin, Ian Olver, John F Thompson, Richard F Brown, Phyllis N Buto

    SSIMS Molecular Selective Imaging: a new diagnostic tool to investigate metal passivators in scrapped transformers

    No full text
    In every high voltage grid, the replacement of assets is a slow but steady process that guarantees long-term reliability of the power distribution networks. The prioritisation of such interventions is based on complex rating criteria specifically designed to highlight potential issues of certain machines (or families of machines) in need of care. Given the tremendous costs of operations such as the replacement of a power transformer it is not surprising to observe constant efforts devoted to finding new and better monitoring and diagnostic tools. These are capable of delivering invaluable information about the conditions of a transformer, in service or after it is either failed or proactively scrapped, allowing a better comprehension of underlying chemical-physical phenomena occurring. Ideally, advanced monitoring and diagnostic tools should ultimately result in improved rating parameters to be applied in the evaluation of future interventions. This feasibility study evaluates the use of static secondary ion mass spectrometry (SSIMS) molecular selective imaging as a diagnostic tool for power transformer. SSIMS is herein demonstrated to be able to assess, without doubts, the presence and integrity of the passivation layer produced by Irgamet®39 on copper surfaces in laboratory tests. The technique has also been tested on real samples collected from one of the phases of a 400/275kV autotransformer proactively scrapped and proved to be applicable without significant sample preparation. The possibility of its use in the study of the distribution of Irgamet®39 across the windings is also demonstrated. Further development of SSIMS as a diagnostic tool would be significantly increasing the grade of detail at which scrapped/failed units could be inspected. A better understanding on how the operating conditions or the design of a transformer can affect the anticorrosion protection layer at the molecular level would open the way to significant ad hoc improvements of both operative guidelines and rating criteria for power transformers

    Two-point functions for SU(3) Polyakov Loops near T_c

    Full text link
    We discuss the behavior of two point functions for Polyakov loops in a SU(3) gauge theory about the critical temperature, T_c. From a Z(3) model, in mean field theory we obtain a prediction for the ratio of masses at T_c, extracted from correlation functions for the imaginary and real parts of the Polyakov loop. This ratio is m_i/m_r = 3 if the potential only includes terms up to quartic order in the Polyakov loop; its value changes as pentic and hexatic interactions become important. The Polyakov Loop Model then predicts how m_i/m_r changes above T_c.Comment: 5 pages, no figures; reference adde

    Relaxation Methods for Mixed-Integer Optimal Control of Partial Differential Equations

    Full text link
    We consider integer-restricted optimal control of systems governed by abstract semilinear evolution equations. This includes the problem of optimal control design for certain distributed parameter systems endowed with multiple actuators, where the task is to minimize costs associated with the dynamics of the system by choosing, for each instant in time, one of the actuators together with ordinary controls. We consider relaxation techniques that are already used successfully for mixed-integer optimal control of ordinary differential equations. Our analysis yields sufficient conditions such that the optimal value and the optimal state of the relaxed problem can be approximated with arbitrary precision by a control satisfying the integer restrictions. The results are obtained by semigroup theory methods. The approach is constructive and gives rise to a numerical method. We supplement the analysis with numerical experiments

    Methods of a national colorectal cancer cohort study: the PIPER Project

    Get PDF
    A national study looking at bowel cancer in New Zealand has previously been completed (the PIPER Project). The study included 5,610 patients and collected medical information about how each person was found to have bowel cancer and the treatment they received. This paper reports how the study was carried out. The information collected in the study will be used to look at the quality of care being provided to New Zealand patients with bowel cancer, and to find out if differences in care occur based on where people live, their ethnicity and their socioeconomic status

    Beyond the Shade of the Oak Tree: The Recent Growth of Johannine Studies

    Full text link
    The recent growth within Johannine studies has developed as a result of several factors. First, the discovery of the Dead Sea Scrolls led to an appreciation of the Jewishness of John’s origin. Second, new approaches to John’s composition have emerged, followed by a larger set of inquiries as to the Johannine tradition’s relation to parallel traditions. This has been accompanied by a fourth interest: the history of the Johannine situation. Fifth, new literary studies have posed new horizons for interpretation, and sixth, theories continue to abound on the identity of the Beloved Disciple. A seventh development involves new ways of conceiving John’s theological features, leading to an eighth: reconsidering John’s historical features and re-envisioning its historical contributions in new perspective
    corecore