1,774 research outputs found

    The point of maximum curvature as a marker for physiological time series

    Full text link
    We present a geometric analysis of the model of Stirling. In particular we analyze the curvature of a heart rate time series in response to a step like increment in the exercise intensity. We present solutions for the point of maximum curvature which can be used as a marker of physiological interest. This marker defines the point after which the heart rate no longer continues to rapidly rise and instead follows either a steady state or slow rise. These methods are then applied to find analytic solutions for a mono exponential model which is commonly used in the literature to model the response to a moderate exercise intensity. Numerical solutions are then found for the full model and parameter values presented in Stirling

    Forward jets and forward WW-boson production at hadron colliders

    Get PDF
    In this talk we give a short review of forward jets and forward WW-boson production at hadron colliders, in view of the extraction of footprints of BFKL physics. We argue that at Tevatron energies, dijet production at large rapidity intervals is still subasymptotic with respect to the BFKL regime, thus the cross section is strongly dependent on the various cuts applied in the experimental setup. In addition, the choice of equal transverse momentum cuts on the tagging jets makes the cross section dependent on large logarithms of non-BFKL origin, and thus may spoil the BFKL analysis. For vector boson production in association with two jets, we argue that the configurations that are kinematically favoured tend to have the vector boson forward in rapidity. Thus W+2W + 2 jet production lends itself naturally to extensions to the high-energy limit.Comment: LaTeX, JHEP style, 10 pages, 3 figures. Based on a talk at EPS2001, Budapest, Hungar

    QCD Theory

    Full text link
    Quantum Chromodynamics is an established part of the Standard Model and an essential part of the toolkit for searching for new physics at high-energy colliders. I present a status report on the theory of QCD and review some of the important developments in the past year.Comment: 10 pages, 11 figures, plenary talk presented at ICHEP04, Beijing, China, August 200

    Additional Soft Jets in ttˉ{\rm t\bar{t}} Production at the Tevatron \pp Collider

    Full text link
    A large fraction of top quark events in \pp collisions at 1.8\ \TeV will contain additional soft hadronic jets from gluon bremsstrahlung off the quarks and gluons in the hard processes \qq, gg \to \tt \to \bb \ww. These extra jets can cause complications when attempting to reconstruct mtm_t from the invariant mass of combinations of final-state quarks and leptons. We show how such soft radiation cannot be unambiguously associated with either initial-state radiation or or with final-state radiation off the bb quarks. The top quarks can radiate too, and in fact the pattern of radiation has a very rich structure, which depends on the orientation of the final-state particles with respect to each other and with respect to the beam. We calculate the full radiation pattern of soft jets in the soft gluon approximation and compare with several approximate forms which are characteristic of parton shower Monte Carlos. The implications for top mass measurements are discussed.Comment: plain LaTeX, 13 pages plus 9 figures included as a separate uuencoded file (or avail. from authors); DTP/94/60, UR-136

    Gravitational Clustering from Chi^2 Initial Conditions

    Full text link
    We consider gravitational clustering from primoridal non-Gaussian fluctuations provided by a χ2\chi^2 model, as motivated by some models of inflation. The emphasis is in signatures that can be used to constrain this type of models from large-scale structure galaxy surveys. Non-Gaussian initial conditions provide additional non-linear couplings otherwise forbidden by symmetry that cause non-linear gravitational corrections to become important at larger scales than in the Gaussian case. In fact, the lack of hierarchical scaling in the initial conditions is partially restored by gravitational evolution at scales k>0.1k> 0.1 h/Mpc. However, the bispectrum shows much larger amplitude and residual scale dependence not present in evolution from Gaussian initial conditions that can be used to test this model against observations. We include the effects of biasing and redshift distortions essential to compare this model with galaxy redshift surveys. We also discuss the effects of primordial non-Gaussianity on the redshift-space power spectrum and show that it changes the shape of the quadrupole to monopole ratio through non-linear corrections to infall velocities.Comment: 20 pages, 7 figure

    Developing national obesity policy in middle-income countries: a case study from North Africa

    Get PDF
    Background The prevalence of overweight and obesity is a rapidly growing threat to public health in both Morocco and Tunisia, where it is reaching similar proportions to high-income countries. Despite this, a national strategy for obesity does not exist in either country. The aim of this study was to explore the views of key stakeholders towards a range of policies to prevent obesity, and thus guide policy makers in their decision making on a national level. Methods Using Multicriteria Mapping, data were gathered from 82 stakeholders (from 33 categories in Morocco and 36 in Tunisia) who appraised 12 obesity policy options by reference to criteria of their own choosing. Results The feasibility of policies in practical or political terms and their cost were perceived as more important than how effective they would be in reducing obesity. There was most consensus and preference for options targeting individuals through health education, compared with options that aimed at changing the environment, i.e. modifying food supply and demand (providing healthier menus/changing food composition/food sold in schools); controlling information (advertising controls/mandatory labelling) or improving access to physical activity. In Tunisia, there was almost universal consensus that at least some environmental-level options are required, but in Morocco, participants highlighted the need to raise awareness within the population and policy makers that obesity is a public health problem, accompanied by improving literacy before such measures would be accepted. Conclusion Whilst there is broad interest in a range of policy options, those measures targeting behaviour change through education were most valued. The different socioeconomic, political and cultural contexts of countries need to be accounted for when prioritizing obesity policy. Obesity was not recognized as a major public health priority; therefore, convincing policy makers about the need to prioritize action to prevent obesity, particularly in Morocco, will be a crucial first step

    Extending the paramedic role in rural Australia : a story of flexibility and innovation

    Full text link
    Introduction: This article identifies trends in the evolving practice of rural paramedics and describes key characteristics, roles and expected outcomes for a Rural Expanded Scope of Practice (RESP) model.Methods: A multiple case study methodology was employed to examine the evolution of rural paramedic practice. Paramedics, volunteer ambulance officers and other health professionals were interviewed in four rural regions of south-eastern Australia where innovative models of rural paramedic practice were claimed to exist. The research team collected and thematically analysed the data using the filter of a sociological framework throughout 2005 and 2006.Results: The study found that paramedics are increasingly becoming first line primary healthcare providers in small rural communities and developing additional professional responsibilities throughout the cycle of care.Conclusions: Adoption of the RESP model would mean that paramedics undertake four broad activities as core components of their new role: (1) rural community engagement; (2) emergency response; (3) situated practice; and (4) primary health care. The model&rsquo;s key feature is a capacity to integrate existing paramedic models with other health agencies and health professionals to ensure that paramedic care is part of a seamless system that provides patients with well-organized and high quality care. This expansion of paramedics&rsquo; scope of practice offers the potential to improve patient care and the general health of rural communities.<br /

    Rare decay Z --> neutrino antineutrino photon photon via quartic gauge boson couplings

    Full text link
    We present a detailed calculation of the rare decay Z --> neutrino antineutrino photon photon via the quartic neutral gauge boson coupling Z-Z-photon-photon in the framework of the effective Lagrangian approach. The current experimental bound on this decay mode is then used to constrain the coefficients of this coupling. It is found that the bounds obtained in this way, of the order of 10−110^{-1}, are weaker than the ones obtained from the analysis of triple-boson production at LEP-2Comment: 5 pages, 2 figures, to appear in Physical Review D Brief Report

    W + gamma + jet production as a test of the electromagnetic couplings of W at LHC and SSC

    Full text link
    The reaction pp→W + γ + jet + Xpp \to W \ +\ \gamma\ +\ jet \ +\ X is considered at centre-of-mass energies s=16\sqrt{s} = 16 and 40\;\tev, including anomalous three-gauge-boson couplings κ\kappa and λ\lambda. The possibility of obtaining limits on these quantities by comparison with the standard model is investigated. The radiation zero properties of the subprocess matrix elements are studied. CERN-TH.6753/92, DTP/92/92.Comment: Latex. 5 figures available (EPS files) on reques
    • …
    corecore