5,733 research outputs found

    Praxis in healthcare OR: An empirical behavioural OR study

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    Operational researchers working in academia commonly struggle in attempts to influence practice and decision making in healthcare amid a growing recognition that behaviour is key to effective operational research (OR). To further our understanding of the behavioural factors that operational researchers working in healthcare consider influence their work’s impact, we interviewed 24 OR practitioners working in academia and with experience of working with the UK National Health Service (NHS). The semi-structured interviews were consented, recorded, transcribed, and analysed thematically using a framework approach. Five dominant themes emerged that highlighted: behavioural challenges concerning flexibility, pivoting and the abandonment of projects; the influence of the evolving ambitions, maturity and behaviours of a practitioner’s OR group; the hidden and changing motivations of host healthcare organisations; the reliance of practitioners on intuition and how their praxis is influenced by their agency within their group and its relationships with healthcare organisations; and how attributes of altruism, broader life experience and creative risk-taking influence an individuals’ praxis. In summary, we identified numerous behavioural factors considered important to success that operate within and across individual projects

    Clustering and collisions of heavy particles in random smooth flows

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    Finite-size impurities suspended in incompressible flows distribute inhomogeneously, leading to a drastic enhancement of collisions. A description of the dynamics in the full position-velocity phase space is essential to understand the underlying mechanisms, especially for polydisperse suspensions. These issues are here studied for particles much heavier than the fluid by means of a Lagrangian approach. It is shown that inertia enhances collision rates through two effects: correlation among particle positions induced by the carrier flow and uncorrelation between velocities due to their finite size. A phenomenological model yields an estimate of collision rates for particle pairs with different sizes. This approach is supported by numerical simulations in random flows.Comment: 12 pages, 9 Figures (revTeX 4) final published versio

    Use of modelling to inform public health policy: a case study on the blood-borne transmission of variant-CJD

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    Since the identification of variant Creutzfeldt–Jacob Disease in the late 1980s, the possibility that this disease might be passed on via blood transfusion has presented challenging policy questions for Government and blood services in the UK. This paper discusses the use of mathematical modelling to inform policy in this area of health protection. We focus on the use of a relatively simple analytical model to explore how many such infections might eventually be expected to result in clinical cases under a range of alternative scenarios of interest to policy, and on the potential impact of possible additional counter measures. We comment on the value of triangulating between findings generated using distinct modelling approaches and observational data

    Neutron inelastic scattering investigation of the magnetic excitations in Cu_2Te_2O_5X_2 (X=Br, Cl)

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    Neutron inelastic scattering investigations have been performed on the spin tetrahedral system Cu_2Te_2O_5X_2 (X = Cl, Br). We report the observation of magnetic excitations with a dispersive component in both compounds, associated with the 3D incommensurate magnetic order that develops below TNClT^{Cl}_{N}=18.2 K and TNBrT^{Br}_{N}=11.4 K. The excitation in Cu_2Te_2O_5Cl_2 softens as the temperature approaches TNClT^{Cl}_{N}, leaving diffuse quasi-elastic scattering above the transition temperature. In the bromide, the excitations are present well above TNBrT^{Br}_{N}, which might be attributed to the presence of a degree of low dimensional correlations above TNBrT^{Br}_{N} in this compound

    Efficacy and safety of linagliptin according to patient baseline characteristics: A pooled analysis of three phase 3 trials

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    AbstractBackground and aimsWe aimed to determine if patient baseline characteristics affect responses to linagliptin and identify relevant predictors of glycated hemoglobin (HbA1c) reduction in patients with type 2 diabetes mellitus (T2DM).Methods and resultsData were pooled from three 24-week, placebo-controlled trials of similar design (linagliptin, n = 1651; placebo, n = 607). Patients were categorized according to baseline characteristics: age, T2DM duration, gender, body mass index (BMI), Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), and metabolic syndrome (MetS). Changes from baseline in HbA1c after 24 weeks were assessed with analysis of covariance (ANCOVA). The proportion of patients with baseline HbA1c >7% achieving HbA1c of ≤7% at week 24 were evaluated. Independent predictors of HbA1c response with linagliptin were analyzed in a multivariate analysis with ANCOVA. Linagliptin treatment led to significant mean (SE) placebo-corrected reductions from baseline in HbA1c across all subgroups (−0.42% [±0.11] to −0.79% [0.08]; all p 7% achieving a target HbA1c ≤7% was greater with linagliptin versus placebo (30.2% vs 11.5%; odds ratio 3.82; 95% CI 2.82 to 5.17; p < 0.001). Characteristics significantly predicting HbA1c reductions after 24 weeks were fasting plasma glucose and race (both p < 0.05).ConclusionThis post-hoc analysis supports that linagliptin achieved clinically meaningful improvements in hyperglycemia in patients with diverse clinical characteristics. These improvements were more pronounced in patients without MetS

    Team sport athletes’ perceptions and use of recovery strategies: a mixed-methods survey study

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    Background: A variety of recovery strategies are used by athletes, although there is currently no research that investigates perceptions and usage of recovery by different competition levels of team sport athletes. Methods: The recovery techniques used by team sport athletes of different competition levels was investigated by survey. Specifically this study investigated if, when, why and how the following recovery strategies were used: active land-based recovery (ALB), active water-based recovery (AWB), stretching (STR), cold water immersion (CWI) and contrast water therapy (CWT). Results: Three hundred and thirty-one athletes were surveyed. Fifty-seven percent were found to utilise one or more recovery strategies. Stretching was rated the most effective recovery strategy (4.4/5) with ALB considered the least effective by its users (3.6/5). The water immersion strategies were considered effective/ineffective mainly due to psychological reasons; in contrast STR and ALB were considered to be effective/ineffective mainly due to physical reasons. Conclusions: This study demonstrates that athletes may not be aware of the specific effects that a recovery strategy has upon their physical recovery and thus athlete and coach recovery education is encouraged. This study also provides new information on the prevalence of different recovery strategies and contextual information that may be useful to inform best practice among coaches and athletes

    Heavy particle concentration in turbulence at dissipative and inertial scales

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    Spatial distributions of heavy particles suspended in an incompressible isotropic and homogeneous turbulent flow are investigated by means of high resolution direct numerical simulations. In the dissipative range, it is shown that particles form fractal clusters with properties independent of the Reynolds number. Clustering is there optimal when the particle response time is of the order of the Kolmogorov time scale τη\tau_\eta. In the inertial range, the particle distribution is no longer scale-invariant. It is however shown that deviations from uniformity depend on a rescaled contraction rate, which is different from the local Stokes number given by dimensional analysis. Particle distribution is characterized by voids spanning all scales of the turbulent flow; their signature in the coarse-grained mass probability distribution is an algebraic behavior at small densities.Comment: 4 RevTeX pgs + 4 color Figures included, 1 figure eliminated second part of the paper completely revise
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