3,617 research outputs found

    Mixed methods evaluation of an educational intervention to change mental health nurses' attitudes to people diagnosed with borderline personality disorder

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    Aims and objectives: To evaluate and explore mental health nurses’ responses to and experience of an educational intervention to improve attitudes towards people with a diagnosis of Borderline Personality Disorder. Report findings are concordant with relevant EQUATOR guidelines (STROBE and COREQ).Background: Attitudes towards people with a diagnosis of Borderline Personality Disorder are poorer than for people with other diagnoses. There is limited evidence about what might improve this situation. One intervention with reportedly good effect uses an underlying biosocial model of borderline personality disorder. No previous intervention has been co-produced with an expert-by-experience. We developed and delivered a 1-day intervention comprising these elements.Design: A mixed-methods design was used comprising prospective uncontrolled cohort intervention and qualitative elements. Participants were mental health nursing staff working in inpatient and community settings in one NHS Board in Scotland, UK.Methods: Measurement of cognitive and emotional attitudes to people with a borderline personality diagnosis at pre- and post- intervention (N =28) and at 4-month follow-up. Focus groups were used to explore participants’ experiences of the intervention (N =11).Results: Quantitative evaluation revealed some sustained changes consistent with expected attitudinal gains in relation to the perceived treatment characteristics of this group, the perception of their suicidal tendencies, and negative attitudes in general. Qualitative findings revealed some hostility towards the underpinning biosocial model and positive appreciation for the involvement of an expert-by-experience. Conclusions: Sustained benefits of an educational intervention for people working with people diagnosed with BPD in some but not all areas. Participants provided contrasting messages about what they think will be useful.Relevance to clinical practice: The study provides further evidence for incorporation of a biosocial model into staff training as well as the benefits of expert-by-experience co-production. Mental health nurses, however, believe that more well-resourced services are the key to improving care. <br/

    Knots, Braids and Hedgehogs from the Eikonal Equation

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    The complex eikonal equation in the three space dimensions is considered. We show that apart from the recently found torus knots this equation can also generate other topological configurations with a non-trivial value of the π2(S2)\pi_2(S^2) index: braided open strings as well as hedgehogs. In particular, cylindric strings i.e. string solutions located on a cylinder with a constant radius are found. Moreover, solutions describing strings lying on an arbitrary surface topologically equivalent to cylinder are presented. We discus them in the context of the eikonal knots. The physical importance of the results originates in the fact that the eikonal knots have been recently used to approximate the Faddeev-Niemi hopfions.Comment: 15 pages, 5 figure

    Experimental test of higher-order Laguerre–Gauss modes in the 10 m Glasgow prototype interferometer

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    Brownian noise of dielectric mirror coatings is expected to be one of the limiting noise sources, at the peak sensitivity, of next generation ground based interferometric gravitational wave (GW) detectors. The use of higher-order Laguerre–Gauss (LG) beams has been suggested to reduce the effect of coating thermal noise in future generations of gravitational wave detectors. In this paper we describe the first test of interferometry with higher-order LG beams in an environment similar to a full-scale gravitational wave detector. We compare the interferometric performance of higher-order LG modes and the fundamental mode beams, injected into a 10 m long suspended cavity that features a finesse of 612, a value chosen to be typical of future gravitational wave detectors. We found that the expected mode degeneracy of the injected LG3, 3 beam was resolved into a multiple peak structure, and that the cavity length control signal featured several nearby zero crossings. The break up of the mode degeneracy is due to an astigmatism (defined as |Rcy − Rcx|) of 5.25 ± 0.5 cm on one of our cavity mirrors with a radius of curvature (Rc) of 15 m. This observation agrees well with numerical simulations developed with the FINESSE software. We also report on how these higher-order mode beams respond to the misalignment and mode mismatch present in our 10 m cavity. In general we found the LG3, 3 beam to be considerably more susceptible to astigmatism and mode mismatch than a conventional fundamental mode beam. Therefore the potential application of higher-order Laguerre–Gauss beams in future gravitational wave detectors will impose much more stringent requirements on both mode matching and mirror astigmatism

    Sample size calculations for cluster randomised controlled trials with a fixed number of clusters

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    Background\ud Cluster randomised controlled trials (CRCTs) are frequently used in health service evaluation. Assuming an average cluster size, required sample sizes are readily computed for both binary and continuous outcomes, by estimating a design effect or inflation factor. However, where the number of clusters are fixed in advance, but where it is possible to increase the number of individuals within each cluster, as is frequently the case in health service evaluation, sample size formulae have been less well studied. \ud \ud Methods\ud We systematically outline sample size formulae (including required number of randomisation units, detectable difference and power) for CRCTs with a fixed number of clusters, to provide a concise summary for both binary and continuous outcomes. Extensions to the case of unequal cluster sizes are provided. \ud \ud Results\ud For trials with a fixed number of equal sized clusters (k), the trial will be feasible provided the number of clusters is greater than the product of the number of individuals required under individual randomisation (nin_i) and the estimated intra-cluster correlation (ρ\rho). So, a simple rule is that the number of clusters (κ\kappa) will be sufficient provided: \ud \ud κ\kappa > nin_i x ρ\rho\ud \ud Where this is not the case, investigators can determine the maximum available power to detect the pre-specified difference, or the minimum detectable difference under the pre-specified value for power. \ud \ud Conclusions\ud Designing a CRCT with a fixed number of clusters might mean that the study will not be feasible, leading to the notion of a minimum detectable difference (or a maximum achievable power), irrespective of how many individuals are included within each cluster. \ud \u

    Developmental Defects Mediated by the P1/HC-Pro Potyviral Silencing Suppressor Are Not Due to Misregulation of AUXIN RESPONSE FACTOR 8

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    Plant viral suppressors of RNA silencing induce developmental defects similar to those caused by mutations in genes involved in the microRNA pathway. A recent report has attributed viral suppressor-mediated developmental defects to up-regulation of AUXIN RESPONSE FACTOR 8 (ARF8), a target of miR167. The key piece of evidence was that the developmental defects in transgenic Arabidopsis (Arabidopsis thaliana) expressing viral suppressors were greatly alleviated in the F1 progeny of a cross with plants carrying the arf8-6 mutation. Arf8-6 is a SALK line T-DNA insertion mutant, a class of mutations prone to inducing transcriptional silencing of transgenes expressed from the 35S promoter. We have reinvestigated the role of ARF8 in viral suppressor-mediated developmental defects, using two independent arf8 mutations and the P1/HC-Pro potyviral suppressor of silencing. Progeny of a cross between P1/HC-Pro transgenic Arabidopsis and the arf8-6 T-DNA insertion mutant showed little effect on the P1/HC-Pro phenotype in the F1 generation, but almost all arf8-6/P1/HC-Pro progeny had lost the phenotype in the F2 generation. However, the loss of phenotype in the F2 generation was not correlated with the number of functional copies of the ARF8 gene. Instead, it reflected transcriptional silencing of the P1/HC-Pro transgene, as evidenced by a pronounced decrease in P1/HC-Pro mRNA and the appearance of 35S promoter small interfering RNAs. Furthermore, an independent loss-of-function point mutation, Arf8-8, had no detectable effects on P1/HC-Pro phenotype in either the F1 or F2 generations. Together, these data argue against the previously reported role of increased ARF8 expression in developmental defects caused by P1/HC-Pro

    The Next Generation Virgo Cluster Survey. VII. The intrinsic shapes of low-luminosity galaxies in the core of the Virgo cluster, and a comparison with the Local Group

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    (Abridged) We investigate the intrinsic shapes of low-luminosity galaxies in the central 300 kpc of the Virgo cluster using deep imaging obtained as part of the NGVS. We build a sample of nearly 300 red-sequence cluster members in the yet unexplored 14<Mg<8-14 < M_{g} < -8 magnitude range. The observed distribution of apparent axis ratios is then fit by families of triaxial models with normally-distributed intrinsic ellipticities and triaxialities. We develop a Bayesian framework to explore the posterior distribution of the model parameters, which allows us to work directly on discrete data, and to account for individual, surface brightness-dependent axis ratio uncertainties. For this population we infer a mean intrinsic ellipticity E=0.43, and a mean triaxiality T=0.16. This implies that faint Virgo galaxies are best described as a family of thick, nearly oblate spheroids with mean intrinsic axis ratios 1:0.94:0.57. We additionally attempt a study of the intrinsic shapes of Local Group satellites of similar luminosities. For the LG population we infer a slightly larger mean intrinsic ellipticity E=0.51, and the paucity of objects with round apparent shapes translates into more triaxial mean shapes, 1:0.76:0.49. We finally compare the intrinsic shapes of NGVS low-mass galaxies with samples of more massive quiescent systems, and with field, star-forming galaxies of similar luminosities. We find that the intrinsic flattening in this low-luminosity regime is almost independent of the environment in which the galaxy resides--but there is a hint that objects may be slightly rounder in denser environments. The comparable flattening distributions of low-luminosity galaxies that have experienced very different degrees of environmental effects suggests that internal processes are the main drivers of galaxy structure at low masses--with external mechanisms playing a secondary role.Comment: Accepted to ApJ. 18 pages, 12 figure

    Instability of insular tree communities in an Amazonian mega-dam is driven by impaired recruitment and altered species composition

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    Mega-dams create highly fragmented archipelagos, affecting biodiversity and ecosystem functioning in remnant forest isolates. This study assessed the long-term impact of dam-induced fragmentation on insular tropical tree communities, with the aim of generating robust recommendations to mitigate some of the detrimental biodiversity impacts associated with future dam development. We inventoried adult and sapling trees across 89 permanent plots, located on 36 islands and in three mainland continuous forest sites in the Balbina Dam, Brazilian Amazon. We examined differences in recruitment, structure, and composition of sapling and adult tree communities, in relation to plot-, patch- and landscape-scale attributes including area, isolation, and fire severity. Islands harboured significantly lower sapling (mean ± 95% CI 48.6 ± 3.8) and adult (5 ± 0.2) tree densities per 0.01 ha, than nearby mainland continuous forest (saplings, 65.7 ± 7.5; adults, 5.6 ± 0.3). Insular sapling and adult tree communities were more dissimilar than in mainland sites, and species compositions showed a directional shift away from mainland forests, induced by fire severity, island area, and isolation. Insular sapling recruitment declined with increasing fire severity; tree communities with higher community-weighted mean wood density showed the greatest recruitment declines. Our results suggest that insular tree communities are unstable, with rare species becoming extinction-prone due to reduced tree recruitment and density on islands, potentially leading to future losses in biodiversity and ecosystem functioning across Balbina's >3,500 reservoir islands. Policy implications. In Balbina, fire and reduced habitat area and connectivity were drivers of tree community decay after only 28 years of insularization, despite strict protection provided by the ~940,000 ha Uatumã Biological Reserve. Given that many dams are planned for lowland, moderately undulating Amazonia, we recommend that dam development strategy explicitly considers (a) dam location, aiming to minimize creation of small (<10 ha) and isolated islands, (b) maintaining reservoir water levels during droughts to reduce fire risk, and (c) including aggregate island area in environmental impact and offset calculations. Ideally, we recommend that alternatives to hydropower be sought in lowland tropical regions, due to the far-reaching biodiversity losses and ecosystem disruption caused by river impoundment
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