33 research outputs found

    On Chiral Mesons in AdS/CFT

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    We analyze the spectra of non-chiral and chiral bifundamental mesons arising on intersecting D7-branes in AdS5×S5AdS_{5}\times S^{5}. In the absence of magnetic flux on the curve of intersection, the spectrum is non-chiral, and the dual gauge theory is conformal in the quenched/probe approximation. For this case we calculate the dimensions of the bifundamental mesonic operators. We then consider magnetization of the D7-branes, which deforms the dual theory by an irrelevant operator and renders the mesons chiral. The magnetic flux spoils the conformality of the dual theory, and induces a D3-brane charge that becomes large in the ultraviolet, where the non-normalizable bifundamental modes are rapidly divergent. An ultraviolet completion is therefore necessary to calculate the correlation functions in the chiral case. On the other hand, the normalizable modes are very well localized in the infrared, leading to new possibilities for local model-building on intersecting D7-branes in warped geometries.Comment: 32 pages, 4 figure

    Unpacking the foundational dimensions of work integration social enterprise: the development of an assessment tool

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    Purpose The aim of this exploratory, mixed methods study was to develop and test a tool that identifies foundational dimensions of work integration social enterprises (WISEs) for use in empirical studies and enterprise self-assessment. Construction of the initial prototype was based upon a review of the literature and prior qualitative research by the authors. Design/methodology/approach A 20-item question pool with a four-point response scale was constructed to explore WISE business and employment practices and strategies for worker growth and development. Three sequential field tests were conducted with the prototype – the first with 5 Canadian WISEs, the second with 14 WISEs in the UK and the third with 6 Canadian WISEs involved in an outcome study in the mental health sector. Each field test included completion of the questionnaire by persons with managerial responsibility within the WISE and evaluative feedback captured through questions on the applicability and interpretability of the items. Findings Testing of the prototype instrument revealed the inherent diversity in the field and the difficulty in creating questions that both embrace that diversity and produce unidimensional variables definable along a spectrum. A number of challenges with question structure were identified and have been modified throughout the iterative testing process. Research limitations/implications This study identified central domains for inclusion in a multi-dimensional WISE assessment tool. Further testing will help further refine scaling and establish psychometric properties. Originality/value This measure will provide a descriptive profile of WISEs across sectors and identify WISE core dimensions for research and organizational development. </jats:sec

    Instanton resummation and the Weak Gravity Conjecture

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    We develop methods for resummation of instanton lattice series. Using these tools, we investigate the consequences of the Weak Gravity Conjecture for large-field axion inflation. We find that the Sublattice Weak Gravity Conjecture implies a constraint on the volume of the axion fundamental domain. However, we also identify conditions under which alignment and clockwork constructions, and a new variant of N -flation that we devise, can evade this constraint. We conclude that some classes of low-energy effective theories of large-field axion inflation are consistent with the strongest proposed form of the Weak Gravity Conjecture, while others are not

    A real parametric characterisation of ex-service compressor blade leading edges

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    In-service the degradation of compressor blade leading edges can have a disproportional effect on compressor efficiency. The high surface curvature in this region makes quantifying the surface finish of this sensitive and prominent region difficult. An automated technique that characterises the roughness of the leading edge in terms of areal parameters is presented. A set of ex-service blades of differing sizes are used to demonstrate the procedure. Improved characterisation of this blade region will allow engine companies to better understand where in-service deterioration has the greatest effect and inform them as to how they might minimise the effect. The present work shows that the leading edges of compressor blades exhibit a significantly higher characteristic surface roughness than other blade regions, and the spatial distribution of peaks in this characteristic roughness is detailed. In addition it is shown that peak wear and roughness are not uniformly correlated

    Nursing Innovation, from Process to Product: A Scoping Review

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    Aim. To review the current literature on the developing role of nursing innovation, specifically, those nurses who have progressed their innovative practice into product development. Design. A scoping review was conducted utilising the Population, Concept, Context framework and the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews. Data Sources. An initial search was performed in February 2023 with a repeat search and revision to the review completed in September 2023. Electronic searches of the British Nursing Index, Current Index of Nursing Allied Health Literature, Emerald Insight, National Health Service Knowledge and Library Hub, and Google Scholar™ were undertaken using the terms Nursing AND (new product development) AND (device innovation). Two authors (LS and MS) also undertook hand searching of relevant reference lists. Review Methods. Two authors were involved in the screening process of available and relevant literature (LS and MS) with the third author (FH) available for decision-making in the event of any generated disagreements. Results. We undertook a review of seventeen papers from 274 results. The impetus of nursing innovation, defining the nurse inventor, facilitators to the nurse inventor concept, and barriers to the nurse inventor concept were all identified as themes to be explored. Conclusion. The nurse inventor concept requires further challenge and clarity. Nurses should aim for a consensus of definition, typology, scope of practice, and job planning. Healthcare institutions should acknowledge and explore this novel role in detail, with consideration afforded to how the role is to be specified and integrated into today’s nursing practice roles. Reporting Method. Adherence to EQUATOR guidance was achieved through the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews

    Purulent Skin and Soft Tissue Infections, Challenging the Practice of Incision and Drainage: A Scoping Review

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    Aim. To generate a landscape of the current knowledge in the interventional management and outcomes of purulent skin and soft tissue infections. Design. This study is a scoping review. Methods. Electronic searches were undertaken using CINAHL, Medline, Cochrane Library, British Nursing Index, Science Direct, the National Health Service knowledge and library hub, ClinicalTrials.gov, and MedNar. The population, concept, context framework, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews were utilised, supporting a rigorous appraisal and synthesis of literature. Data Sources. The initial search and synthesis of literature were completed in January 2022 with repeat searches completed in March 2022 and July 2023. There were no imposed chronological parameters placed on the returned literature. Results. Nineteen papers were reviewed. Incision and drainage with primary closure, needle aspiration, loop drainage, catheter drainage, and suction drainage are viable adjuncts or alternatives to the traditional surgical management of skin and soft tissue abscesses. Conclusion. Despite the empirically favourable alternatives to the incision and drainage technique demonstrated, this does not appear to be driving a change in clinical practice. Future research must now look to mixed and qualitative evidence to understand the causative mechanisms of incision and drainage and its ritualistic practice. Implications. Ritual surgical practices must be challenged if nurses are to improve the treatment and management of this patient group. This will lead to further practice innovation. Impact: This study explored the challenges posed to patients, clinicians, nurses, and stakeholders, resulting from the ritualistic practice of the incision and drainage technique in purulent skin or soft tissue abscesses. Empirically and holistically viable alternatives were identified, impacting all identified entities and recommending a wider holistic study. Reporting Method. Adherence to EQUATOR guidance was achieved through the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews

    Modelling water vapor permeability through atomic layer deposition coated photovoltaic barrier defects

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    Transparent barrier films such as Al2O3 used for prevention of oxygen and/or water vapour permeation are the subject of increasing research interest when used for the encapsulation of flexible photovoltaic modules. However, the existence of micro-scale defects in the barrier surface topography has been shown to have the potential to facilitate water vapour ingress, thereby reducing cell efficiency and causing internal electrical shorts. Previous work has shown that small defects (≤ 3 μm lateral dimension) were less significant in determining water vapour ingress. In contrast, larger defects (≥ 3 μm lateral dimension) seem to be more detrimental to the barrier functionality. Experimental results based on surface topography segmentation analysis and a model presented in this paper, will be used to test the hypothesis that the major contributing defects to water vapour transmission rate are small numbers of large defects. The model highlighted in this study has the potential to be used for gaining a better understanding of photovoltaic module efficiency and performance

    The effect of two β-alanine dosing strategies on 30-minute rowing performance: a randomized, controlled trial

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    Background: β-alanine (βA) supplementation has been shown to increase intramuscular carnosine content and subsequent high-intensity performance in events lasting <4 minutes, which may be dependent on total, as opposed to daily, dose. The ergogenic effect of βA has also been demonstrated for 2000-m rowing performance prompting interest in whether βA may be beneficial for sustained aerobic exercise. This study therefore investigated the effect of two βA dosing strategies on 30-minute rowing and subsequent sprint performance. Methods: Following University Ethics approval, twenty-seven healthy, male rowers (age: 24±2 years; body-height: 1.81±0.02m; body-mass: 82.3±2.5kg; body-fat: 14.2±1.0%) were randomised in a double-blind manner to 4 weeks of: i) βA (2.4 g·d-1, βA1); ii) matched total βA (4.8g on alternate days, βA2); or iii) cornflour placebo (2.4 g·d-1, PL). Participants completed a laboratory 30-minute rowing time-trial, followed by 3x30s maximal sprint efforts at days 0, 14 and 28 (T1-T3). Total distance (m), average power (W), relative average power (W·kg-1), cardio-respiratory measures and perceived exertion were assessed for each 10-minute split. Blood lactate ([La-]b mmol·L-1) was monitored pre-post time-trial and following maximal sprint efforts. A 3-way repeated measures ANOVA was employed for main analyses, with Bonferonni post-hoc assessment (P≤0.05). Results: Total 30-minute time-trial distance significantly increased from T1-T3 within βA1 only (7397±195m to 7580±171m, P=0.002, ƞp2 = 0.196), including absolute average power (194.8±18.3W to 204.2±15.5W, P=0.04, ƞp2=0.115) and relative average power output (2.28±0.15W·kg-1 to 2.41±0.12W·kg-1, P=0.031, ƞp2= 0.122). These findings were potentially explained by within-group significance for the same variables for the first 10 minute split (P≤0.01), and for distance covered (P=0.01) in the second 10-minute split. However, no condition x time interactions were observed. No significant effects were found for sprint variables (P>0.05) with comparable values at T3 for mean distance (βA1: 163.9±3.8m; βA2: 161.2±3.5m; PL: 162.7±3.6m), average power (βA1: 352.7±14.5W; βA2: 342.2±13.5W; PL: 348.2±13.9W) and lactate (βA1: 10.0±0.9mmol·L-1; βA2: 9.2±1.1mmol·L-1; PL: 8.7±0.9mmol·L-1). Conclusions: Whilst daily βA may confer individual benefits, these results demonstrate limited impact of βA (irrespective of dosing strategy) on 30-minute rowing or subsequent sprint performance. Further investigation of βA dosage > 2.4 g·d-1 and/or chronic intervention periods (>4-8 weeks) may be warranted based on within-group observations
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