1,072 research outputs found

    A Classic Grounded Theory Study exploring the Perceptions of Stress for People who have experienced a Transient Ischaemic Attack

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    Background: Stress is a known risk factor for stroke, but there is a lack of understanding of the role stress plays in transient ischaemic attack (TIA). TIA is a warning sign of stroke, but effective management of risk factors can reduce the threat for the individual. Research Aim and Questions: The aim was to explore the perceptions of stress for people who have experienced a TIA and address the following questions: 1. What is the patients’ understanding of the relationship between perceived stress and TIA? 2. How has perceived stress affected the patients’ physical and mental health and well-being? 3. What actions has the patient taken to influence perceived stress and have these actions made a difference? Methodology and Methods: The study was conducted following a classic grounded theory tradition. Thirteen semi-structured interviews were undertaken with people who had experienced a TIA. Participants were recruited from outpatient clinics located in three Scottish Health Boards. Findings: Perceived stress was commonly experienced by participants and it was a significant feature throughout their TIA journey. Although not universally acknowledged as a contributing cause of TIA, stress formed part of their lived experiences. The presence or absence of perceived stress was an influencing force in relation to their mental and physical health and well-being. Factors that influenced stress could stabilise or destabilise a sense of equilibrium. Equilibrium was the achievement of a balance between interdependent elements and formed the core category: the equilibrium of health and well-being for the individual. Conclusions: The study led to the discovery of the substantive theory: if perceived stress can be effectively self-managed after a TIA, a state of equilibrium can be achieved which supports health and well-being. This new knowledge raises the opportunity to improve health and well-being after TIA and potentially reduce the risk of stroke

    Redundant and irrelevant data in problem solving

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    Activities to support the implementation of complex interventions as part of routine care: a review of the quality of reporting in cluster randomised controlled trials

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    Objective: To review a sample of cluster randomised controlled trials and explore the quality of reporting of (1) enabling or support activities provided to the staff during the trial, (2) strategies used to monitor fidelity throughout the trial and (3) the extent to which the intervention being tested was delivered as planned. Design: A descriptive review. Data sources and study selection: We searched MEDLINE for trial reports published between 2008 and 2014 with combinations of the search terms 'randomised', 'cluster', 'trial', 'study', 'intervention' and 'implement∗'. We included trials in which healthcare professionals (HCPs) implemented the intervention being tested as part of routine practice. We excluded trials (1) conducted in non-health services settings, (2) where the intervention explicitly aimed to change the behaviours of the HCPs and (3) where the trials were ongoing or for which only trial protocols were available. Data collection: We developed a data extraction form using the Template for Intervention Description and Replication (TIDieR checklist). Review authors independently extracted data from the included trials and assessed quality of reporting for individual items. Results: We included 70 publications (45 results publications, 25 related publications). 89% of trials reported using enabling or support activities. How these activities were provided (75.6%, n=34) and how much was provided (73.3%, n=33) were the most frequently reported items. Less than 20% (n=8) of the included trials reported that competency checking occurred prior to implementation and data collection. 64% (n=29) of trials reported collecting measures of implementation. 44% (n=20) of trials reported data from these measures. Conclusions: Although enabling and support activities are reported in trials, important gaps exist when assessed using an established checklist. Better reporting of the supports provided in effectiveness trials will allow for informed decisions to be made about financial and resource implications for wide scale implementation of effective interventions

    Associations of inflammatory and hemostatic variables with the risk of recurrent stroke

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    <p><b>Background and Purpose:</b> Several prospective studies have shown significant associations between plasma fibrinogen, viscosity, C-reactive protein (CRP), fibrin D-dimer, or tissue plasminogen activator (tPA) antigen and the risk of primary cardiovascular events. Little has been published on the associations of these variables with recurrent stroke. We studied such associations in a nested case-control study derived from the Perindopril Protection Against Recurrent Stroke Study (PROGRESS).</p> <p><b>Methods:</b> Nested case-control study of ischemic (n=472) and hemorrhagic (n=83) strokes occurring during a randomized, placebo-controlled multicenter trial of perindopril-based therapy in 6105 patients with a history of stroke or transient ischemic attack. Controls were matched for age, treatment group, sex, region, and most recent qualifying event at entry to the parent trial.</p> <p><b>Results:</b> Fibrinogen and CRP were associated with an increased risk of recurrent ischemic stroke after accounting for the matching variables and adjusting for systolic blood pressure, smoking, peripheral vascular disease, and statin and antiplatelet therapy. The odds ratio for the last compared with the first third of fibrinogen was 1.34 (95% CI, 1.01 to 1.78) and for CRP was 1.39 (95% CI, 1.05 to 1.85). After additional adjustment for each other, these 2 odds ratios stayed virtually unchanged. Plasma viscosity, tPA, and D-dimer showed no relationship with recurrent ischemic stroke, although tPA was significant for lacunar and large artery subtypes. Although each of these variables showed a negative relationship with recurrent hemorrhagic stroke, none of these relationships achieved statistical significance.</p> <p><b>Conclusions:</b> Fibrinogen and CRP are risk predictors for ischemic but not hemorrhagic stroke, independent of potential confounders.</p&gt

    How do pilot and feasibility studies inform randomised placebo-controlled trials in surgery? : A systematic review

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    © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.Peer reviewedPublisher PD

    An adaptive technique for content-based image retrieval

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    We discuss an adaptive approach towards Content-Based Image Retrieval. It is based on the Ostensive Model of developing information needs—a special kind of relevance feedback model that learns from implicit user feedback and adds a temporal notion to relevance. The ostensive approach supports content-assisted browsing through visualising the interaction by adding user-selected images to a browsing path, which ends with a set of system recommendations. The suggestions are based on an adaptive query learning scheme, in which the query is learnt from previously selected images. Our approach is an adaptation of the original Ostensive Model based on textual features only, to include content-based features to characterise images. In the proposed scheme textual and colour features are combined using the Dempster-Shafer theory of evidence combination. Results from a user-centred, work-task oriented evaluation show that the ostensive interface is preferred over a traditional interface with manual query facilities. This is due to its ability to adapt to the user's need, its intuitiveness and the fluid way in which it operates. Studying and comparing the nature of the underlying information need, it emerges that our approach elicits changes in the user's need based on the interaction, and is successful in adapting the retrieval to match the changes. In addition, a preliminary study of the retrieval performance of the ostensive relevance feedback scheme shows that it can outperform a standard relevance feedback strategy in terms of image recall in category search

    The price of inscrutability

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    In our reasoning we depend on the stability of language, the fact that its signs do not arbitrarily change in meaning from moment to moment.(Campbell, 1994, p.82) Some philosophers offer arguments contending that ordinary names such as “London” are radically indeterminate in reference. The conclusion of such arguments is that there is no fact of the matter whether “London” refers to a city in the south of England, or whether instead it refers to Sydney, Australia. Some philosophers have even suggested that we accept the conclusion of these arguments. Such a position seems crazy to many; but what exactly goes wrong if one adopts such a view? This paper evaluates the theoretical costs incurred by one who endorses extreme inscrutability of reference (the ‘inscrutabilist’). I show that there is one particular implication of extreme inscrutability which pushes the price of inscrutabilism too high. An extension of the classic ‘permutation’ arguments for extreme inscrutability allow us to establish what I dub ‘extreme indexical inscrutability’. This result, I argue, unacceptably undermines the epistemology of inference. The first half of the paper develops the background of permutation arguments for extreme inscrutability of reference and evaluates some initial attempts to make trouble for the inscrutabilist. Sections 1 and 2 describe the setting of the original permutation arguments for extreme inscrutability. Sections 3 and 4 survey four potential objections to extreme inscrutability of reference, including some recently raised in Vann McGee’s excellent (2005a). Sections 5 sketches how the permutation arguments can be generalized to establish extreme indexical inscrutability; and shows how this contradicts a ‘stability principle’—that our words do not arbitrarily change their reference from one moment to the next—which I claim plays a vital role in the epistemology of inference. The second half of the paper develops in detail the case for thinking that language is stable in the relevant sense. In section 6, I use this distinction to call into question the epistemological relevance of validity of argument types; Kaplan’s treatment of indexical validity partially resolves this worry, but there is a residual problem. In section 7, I argue that stability is exactly what is needed to bridge this final gap, and so secure the relevance of validity to good inferential practice. Section 8 responds to objections to this claim. An appendix to the paper provides formal backing for the results cited in this paper, including a generalization of permutation arguments to the kind of rich setting required for a realistic semantics of natural language.1 Extreme indexical inscrutability results can be proved within this setting. The first half of the paper shows that the inscrutabilist is committed to extreme indexical inscrutability, which implies that language not determinately ‘stable’. The second half of the paper argues that good inference requires stability. The price of inscrutabilism, therefore, is to sever the connection between the validity of argument-forms and inferential practice: and this is too high a price to pay

    On the low-energy limit of the QED N-photon amplitudes

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    We derive an explicit formula for the low energy limits of the one-loop, on-shell, massive N-photon amplitudes, for arbitrary N and all helicity assignments, in scalar and spinor QED. The two-loop corrections to the same amplitudes are obtained for up to the ten point case. All photon amplitudes with an odd number of `+' helicities are shown to vanish in this limit to all loop orders.Comment: 15 pages, LaTeX2e, typo in (4.2) correcte
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