1,809 research outputs found

    Screening for health risks: A social science perspective

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    Health screening promises to reduce risks to individuals via probabilistic sifting of populations for medical conditions. The categorisation and selection of 'conditions' such as cardiovascular events, dementia and depression for screening itself requires prior interpretive labour which usually remains unexamined. Screening systems can take diverse organisational forms and varying relationships to health status, as when purported disease precursors, for example 'pre-cancerous' polyps, or supposed risk factors, such as high cholesterol themselves, become targets for screening. Screening at best yields small, although not necessarily unworthwhile, net population health gains. It also creates new risks, leaving some individuals worse-off than if they had been left alone. The difficulties associated with attempting to measure small net gains through randomised controlled trials are sometimes underestimated. Despite endemic doubts about its clinical utility, bibliometric analysis of published papers shows that responses to health risks are coming to be increasingly thought about in terms of screening. This shift is superimposed on a strengthening tendency to view health through the lens of risk. It merits further scrutiny as a societal phenomenon

    Vine and soil-based measures of water status in a Tempranillo vineyard

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    Seasonal changes of leaf and stem water potential and midday stomatal conductance (gs) of Tempranillo grapevines were determined in irrigated and non-irrigated vines in 2003 and 2004. Leaf water potential was measured at pre-dawn (Ψpd) and at midday (Ψlmd), while stem water potential was measured in the early morning (Ψsem) and at midday (Ψsmd). At Ψpd to -0.54 MPa rain-fed and irrigated vines had similar midday Ψl and Ψs. This was due to both, stomatal closure and reduction of leaf area. Under these conditions, Ψpd and Ψsem were better water stress indicators than midday Ψ. In both years a close correlation was found between Ψpd and Ψsem. However, for a given Ψpd, Ψsem of vines was lower in 2004 than in 2003. This was probably due to the larger leaf area developed by vines in 2004. Stomatal conductance reflected reasonably well differences in the vine water status but its variability was much higher than that of Ψ. Moreover, the afternoon depression of stomatal conductance observed even in irrigated plots, indicates that measuring gs early in the morning is more convenient when assessing different treatments.

    Tetragonal tungsten bronze compounds: relaxor vs mixed ferroelectric - dipole glass behavior

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    We demonstrate that recent experimental data (E. Castel et al J.Phys. Cond. Mat. {\bf 21} (2009), 452201) on tungsten bronze compound (TBC) Ba2_2Prx_xNd1x_{1-x}FeNb4_4O15_{15} can be well explained in our model predicting a crossover from ferroelectric (x=0x=0) to orientational (dipole) glass (x=1x=1), rather then relaxor, behavior. We show, that since a "classical" perovskite relaxor like Pb(Mn1/3_{1/3} Nb2/3_{2/3})O3_3 is never a ferroelectric, the presence of ferroelectric hysteresis loops in TBC shows that this substance actually transits from ferroelectric to orientational glass phase with xx growth. To describe the above crossover theoretically, we use the simple replica-symmetric solution for disordered Ising model.Comment: 5 two-column pages, 4 figure

    Dominant g(9/2)^2 neutron configuration in the 4+1 state of 68Zn based on new g factor measurements

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    The gg factor of the 41+4_1^+ state in 68^{68}Zn has been remeasured with improved energy resolution of the detectors used. The value obtained is consistent with the previous result of a negative gg factor thus confirming the dominant 0g9/20g_{9/2} neutron nature of the 41+4_1^+ state. In addition, the accuracy of the gg factors of the 21+2_1^+, 22+2_2^+ and 313_1^- states has been improved an d their lifetimes were well reproduced. New large-scale shell model calculations based on a 56^{56}Ni core and an 0f5/21pg9/20f_{5/2}1pg_{9/2} model space yield a theoretical value, g(41+)=+0.008g(4_1^+) = +0.008. Although the calculated value is small, it cannot fully explain the experimental value, g(41+)=0.37(17)g(4_1^+) = -0.37(17). The magnitude of the deduced B(E2) of the 41+4_1^+ and 21+2_1^+ transition is, however, rather well described. These results demonstrate again the importance of gg factor measurements for nuclear structure determination s due to their specific sensitivity to detailed proton and neutron components in the nuclear wave functions.Comment: 7 pages, 3 figs, submitted to PL

    Modelling the behaviour of microbulk Micromegas in Xenon/trimethylamine gas

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    We model the response of a state of the art micro-hole single-stage charge amplication device (`microbulk' Micromegas) in a gaseous atmosphere consisting of Xenon/trimethylamine at various concentrations and pressures. The amplifying structure, made with photo-lithographic techniques similar to those followed in the fabrication of gas electron multipliers (GEMs), consisted of a 100 um-side equilateral-triangle pattern with 50 um-diameter holes placed at its vertexes. Once the primary electrons are guided into the holes by virtue of an optimized field configuration, avalanches develop along the 50 um-height channels etched out of the original doubly copper-clad polyimide foil. In order to properly account for the strong field gradients at the holes' entrance as well as for the fluctuations of the avalanche process (that ultimately determine the achievable energy resolution), we abandoned the hydrodynamic framework, resorting to a purely microscopic description of the electron trajectories as obtained from elementary cross-sections. We show that achieving a satisfactory description needs additional assumptions about atom-molecule (Penning) transfer reactions and charge recombination to be made

    Topotecan-vincristine-doxorubicin in stage 4 high risk neuroblastoma patients failing to achieve a complete metastatic response to rapid COJEC : a SIOPEN study

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    Purpose : Metastatic response to induction therapy for high-risk neuroblastoma is a prognostic factor. In the International Society of Paediatric Oncology Europe Neuroblastoma (SIOPEN) HR-NBL-1 protocol, only patients with metastatic complete response (CR) or partial response (PR) with <= three abnormal skeletal areas on iodine 123-metaiodobenzylguanidine ([I-123] mIBG) scintigraphy and no bone marrow disease proceed to high dose therapy (HDT). In this study, topotecan-vincristine-doxorubicin (TVD) was evaluated in patients failing to achieve these criteria, with the aim of improving the metastatic response rate. Materials and Methods : Patients with metastatic high-risk neuroblastoma who had not achieved the SIOPEN criteria for HDT after induction received two courses of topotecan 1.5 mg/m(2)/day for 5 days, followed by a 48-hour infusion of vincristine, 2 mg/m(2), and doxorubicin, 45 mg/m(2). Results : Sixty-three patients were eligible and evaluable. Following two courses of TVD, four (6.4%) patients had an overall CR, while 28 (44.4%) had a PR with a combined response rate of 50.8% (95% confidence interval [CI], 37.9 to 63.6). Of these, 23 patients achieved a metastatic CR or a PR with <= 3 mIBG skeletal areas and no bone marrow disease (36.5%; 95% CI, 24.7 to 49.6) and were eligible to receive HDT. Toxicity was mostly haematological, affecting 106 of the 126 courses (84.1%; 95% CI, 76.5 to 90.0), and dose reduction was necessary in six patients. Stomatitis was the second most common nonhematological toxicity, occurring in 20 patients (31.7%). Conclusion : TVD was effective in improving the response rate of high-risk neuroblastoma patients after induction with COJEC enabling them to proceed to HDT. However, the long-term benefits of TVD needs to be determined in randomized clinical trials

    The Operational Impacts of Chief Supply Chain Officers in Manufacturing Firms

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    Many firms have elevated their supply chain management decision-making responsibilities through the creation of ‘Chief Supply Chain Officer’ (CSCO) positions. This is widely attributed to the recognition that superior supply chain operations can generate a competitive advantage. Prior studies have found that firms with CSCOs outperform firms without CSCOs along many financial dimensions. However, these prior efforts did not examine the pathways by which these improvements occur. This study addresses this gap in the literature by investigating whether supply chain characteristics of manufacturing firms differ within firms with CSCOs. To explore this, we investigate the relationship between CSCOs and operational dimensions of supply chain performance using data from the 10-year period between 2008 and 2017. We find that the presence of a CSCO in a firm is associated with shorter cash conversion cycles, lower levels of operational slack, and larger buffers of inventory during periods of high market instability
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