73 research outputs found

    Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

    Full text link
    Average charged multiplicities have been measured separately in bb, cc and light quark (u,d,su,d,s) events from Z0Z^0 decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of bb and light quark events, and reconstructed charmed mesons were used to select cc quark events. We measured the charged multiplicities: nˉuds=20.21±0.10(stat.)±0.22(syst.)\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.}), nˉc=21.28±0.46(stat.)0.36+0.41(syst.)\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.}) nˉb=23.14±0.10(stat.)0.37+0.38(syst.)\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.}), from which we derived the differences between the total average charged multiplicities of cc or bb quark events and light quark events: Δnˉc=1.07±0.47(stat.)0.30+0.36(syst.)\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.}) and Δnˉb=2.93±0.14(stat.)0.29+0.30(syst.)\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.}). We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters

    The association of body mass index with long-term clinical outcomes after ticagrelor monotherapy following abbreviated dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: a prespecified sub-analysis of the GLOBAL LEADERS Trial

    Get PDF
    Background: The efficacy of antiplatelet therapies following percutaneous coronary intervention (PCI) may be affected by body mass index (BMI). Methods and results: This is a prespecified subgroup analysis of the GLOBAL LEADERS trial, a prospective, multicenter, open-label, randomized controlled trial in an all-comer population undergoing PCI, comparing the experimental strategy (23-month ticagrelor monotherapy following 1-month dual antiplatelet therapy [DAPT]) with a reference regimen (12-month aspirin monotherapy following 12-month DAPT). A total of 15,968 patients were stratified by baseline BMI with prespecified threshold of 27 kg/m2. Of those, 6973 (43.7%) patients with a BMI < 27 kg/m2 had a higher risk of all-cause mortality at 2 years than those with BMI ≥ 27 kg/m2 (adjusted HR 1.24, 95% CI 1.02–1.49). At 2 years, the rates of the primary endpoint (all-cause mortality or new Q-wave myocardial infarction) were similar between treatment strategies in either BMI group (pinteraction = 0.51). In acute coronary syndrome, however, the experimental strategy was associated with significant reduction of the primary endpoint compared to the reference strategy in patients with BMI < 27 kg/m2 (HR 0.69, 95% CI 0.51–0.94), but not in the ones with BMI ≥ 27 kg/m2 (pinteraction = 0.047). In chronic coronary syndrome, there was no between-group difference in the efficacy and safety of the two antiplatelet strategies. This is a prespecified subgroup analysis of the GLOBAL LEADERS trial, a prospective, multicenter, open-label, randomized controlled trial in an all-comer population undergoing PCI, comparing the experimental strategy (23-month ticagrelor monotherapy following 1-month dual antiplatelet therapy [DAPT]) with a reference regimen (12-month aspirin monotherapy following 12-month DAPT). A total of 15,968 patients were stratified by baseline BMI with prespecified threshold of 27 kg/m2. Of those, 6973 (43.7%) patients with a BMI < 27 kg/m2 had a higher risk of all-cause mortality at 2 years than those with BMI ≥ 27 kg/m2 (adjusted HR 1.24, 95% CI 1.02–1.49). At 2 years, the rates of the primary endpoint (all-cause mortality or new Q-wave myocardial infarction) were similar between treatment strategies in either BMI group (pinteraction = 0.51). In acute coronary syndrome, however, the experimental strategy was associated with significant reduction of the primary endpoint compared to the reference strategy in patients with BMI < 27 kg/m2 (HR 0.69, 95% CI 0.51–0.94), but not in the ones with BMI ≥ 27 kg/m2 (pinteraction = 0.047). In chronic coronary syndrome, there was no between-group difference in the efficacy and safety of the two antiplatelet strategies. This is a prespecified subgroup analysis of the GLOBAL LEADERS trial, a prospective, multicenter, open-label, randomized controlled trial in an all-comer population undergoing PCI, comparing the experimental strategy (23-month ticagrelor monotherapy following 1-month dual antiplatelet therapy [DAPT]) with a reference regimen (12-month aspirin monotherapy following 12-month DAPT). A total of 15,968 patients were stratified by baseline BMI with prespecified threshold of 27 kg/m2. Of those, 6973 (43.7%) patients with a BMI < 27 kg/m2 had a higher risk of all-cause mortality at 2 years than those with BMI ≥ 27 kg/m2 (adjusted HR 1.24, 95% CI 1.02–1.49). At 2 years, the rates of the primary endpoint (a

    Training future generations to deliver evidence-based conservation and ecosystem management

    Get PDF
    1. To be effective, the next generation of conservation practitioners and managers need to be critical thinkers with a deep understanding of how to make evidence-based decisions and of the value of evidence synthesis. 2. If, as educators, we do not make these priorities a core part of what we teach, we are failing to prepare our students to make an effective contribution to conservation practice. 3. To help overcome this problem we have created open access online teaching materials in multiple languages that are stored in Applied Ecology Resources. So far, 117 educators from 23 countries have acknowledged the importance of this and are already teaching or about to teach skills in appraising or using evidence in conservation decision-making. This includes 145 undergraduate, postgraduate or professional development courses. 4. We call for wider teaching of the tools and skills that facilitate evidence-based conservation and also suggest that providing online teaching materials in multiple languages could be beneficial for improving global understanding of other subject areas.Peer reviewe

    An empirical model to retrieving ocean wave period from nadir altimeter data

    No full text
    Accurate measurement of the ocean wave period is of much scientific interest both operationally and for research. Shipping and offshore industries are keen to obtain real-time and climatological information on wave period in the open ocean to assist the design of sea-going structures and maximise safety at sea. Similarly, wave period is relevant for short-to-medium term ocean and weather forecasting, and more broadly, to ocean circulation and climate research, given the reported dependence of atmosphere-ocean momentum transfer on some measure of sea state development. In principle, full ocean wave spectra can be obtained from satellite synthetic aperture radars (SAR), yet the systematic extraction of wave period information from SAR has so far not been pursued. Hence, global wave period information is presently available only through numerical wave models, and there remain concerns about the lack of large scale validation of the geographical distribution and temporal variability of the modelled ocean waves. Here, we propose that ocean wave period information can be retrieved with adequate accuracy using satellite altimeters. There is evidence that satellite altimeter data contain wave period information, in addition to that on wave height. The existence of sea state development effects on the retrieval of altimeter wind speed is well documented and a few earlier studies have already considered the development of altimeter wave period models. However, the sea state dependence in these semi-empirical models is complex, and in both cases, the datasets of collocated altimeter/buoy measurements used to develop the models spanned only a small range of environmental conditions. In this paper, we present preliminary results of a new, purely empirical, wave period algorithm developed on the basis of the largest to-date dataset of collocated altimeter/buoy spectra measurements. The empirical wave period model is validated using independent collocated altimeter/buoy data, and by computing global monthly wave climatology. These are compared with existing wave period climatologies derived from numerical wave models
    corecore