144 research outputs found

    Extending representation formulas for boundary voltage perturbations of low volume fraction to very contrasted conductivity inhomogeneities

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    Imposing either Dirichlet or Neumann boundary conditions on the boundary of a smooth bounded domain Ω\Omega , we study the perturbation incurred by the voltage potential when the conductivity is modified in a set of small measure. We consider (γn)nN(\gamma _{n})_{n\,\in \,\mathbb{N}}, a sequence of perturbed conductivity matrices differing from a smooth γ0\gamma _{0} background conductivity matrix on a measurable set well within the domain, and we assume (γnγ0)γn1(γnγ0)0(\gamma _{n}-\gamma _{0})\gamma _{n}^{-1}(\gamma _{n}-\gamma _{0})\rightarrow 0 in L1(Ω)L^{1}(\Omega ). Adapting the limit measure, we show that the general representation formula introduced for bounded contrasts in a previous work from 2003 can be extended to unbounded sequences of matrix valued conductivities

    Extending representation formulas for boundary voltage perturbations of low volume fraction to very contrasted conductivity inhomogeneities

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    Imposing either Dirichlet or Neumann boundary conditions on the boundary of a smooth bounded domain Ω\Omega , we study the perturbation incurred by the voltage potential when the conductivity is modified in a set of small measure. We consider (γn)nN(\gamma _{n})_{n\,\in \,\mathbb{N}}, a sequence of perturbed conductivity matrices differing from a smooth γ0\gamma _{0} background conductivity matrix on a measurable set well within the domain, and we assume (γnγ0)γn1(γnγ0)0(\gamma _{n}-\gamma _{0})\gamma _{n}^{-1}(\gamma _{n}-\gamma _{0})\rightarrow 0 in L1(Ω)L^{1}(\Omega ). Adapting the limit measure, we show that the general representation formula introduced for bounded contrasts in a previous work from 2003 can be extended to unbounded sequences of matrix valued conductivities

    Achieving change in primary care—causes of the evidence to practice gap : systematic reviews of reviews

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    Acknowledgements The Evidence to Practice Project (SPCR FR4 project number: 122) is funded by the National Institute of Health Research (NIHR) School for Primary Care Research (SPCR). KD is part-funded by the National Institute for Health Research (NIHR) Collaborations for Leadership in Applied Research and Care West Midlands and by a Knowledge Mobilisation Research Fellowship (KMRF-2014-03-002) from the NIHR. This paper presents independent research funded by the National Institute of Health Research (NIHR). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. Funding This study is funded by the National Institute for Health Research (NIHR) School for Primary Care Research (SPCR).Peer reviewedPublisher PD

    Social Media Content of Idiopathic Pulmonary Fibrosis Groups and Pages on Facebook: Cross-sectional Analysis.

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    BACKGROUND Patients use Facebook as a resource for medical information. We analyzed posts on idiopathic pulmonary fibrosis (IPF)-related Facebook groups and pages for the presence of guideline content, user engagement, and usefulness. OBJECTIVE The objective of this study was to describe and analyze posts from Facebook groups and pages that primarily focus on IPF-related content. METHODS Cross-sectional analysis was performed on a single date, identifying Facebook groups and pages resulting from separately searching "IPF" and "idiopathic pulmonary fibrosis." For inclusion, groups and pages needed to meet either search term and be in English, publicly available, and relevant to IPF. Every 10th post was assessed for general characteristics, source, focus, and user engagement metrics. Posts were analyzed for presence of IPF guideline content, useful scientific information (eg, scientific publications), useful support information (eg, information about support groups), and potentially harmful information. RESULTS Eligibility criteria were met by 12 groups and 27 pages, leading to analysis of 523 posts. Of these, 42% contained guideline content, 24% provided useful support, 20% provided useful scientific information, and 5% contained potentially harmful information. The most common post source was nonmedical users (85%). Posts most frequently focused on IPF-related news (29%). Posts containing any guideline content had fewer likes or comments and a higher likelihood of containing potentially harmful content. Posts containing useful supportive information had more likes, shares, and comments. CONCLUSIONS Facebook contains useful information about IPF, but posts with misinformation and less guideline content have higher user engagement, making them more visible. Identifying ways to help patients with IPF discriminate between useful and harmful information on Facebook and other social media platforms is an important task for health care professionals

    Evidence of disease severity, cognitive and physical outcomes of dance interventions for persons with Parkinson's disease : a systematic review and meta-analysis

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    Background: Patients with Parkinson’s Disease (PD) usually experience worsening of both motor and non-motor symptoms. Dancing has been postulated to help patients with Parkinson’s via several mechanisms that lead to improved physical, cognitive and social functions. Methods: This systematic review was conducted following Cochrane methodology and reported following the PRISMA guideline. Four databases (up to June 2021) were searched for RCTs comparing dance to standard or other physical therapy for improvements in disease severity, quality of life, cognitive and physical outcomes as well as adverse events in patients with PD. We synthesised data using RevMan and included certainty-of-evidence rating (GRADE) for major outcomes. Results: A total of 20 RCTs (N = 723) articles that evaluated Tango, Ballroom, Irish, Waltz-Foxtrot, Folk, Turo, mixed dances and a PD-tailored dance were included. Dancers (versus non-dancers) had better motor experience (MDS-UPDRS 3) (MD -6.01, 95 % CI -9.97 to -3.84; n = 148; 5 RCTs) and improved balance (MiniBest Test) (MD 4.47, 95 % CI 2.29 to 6.66; n = 95; 3 RCTs), with no consistent differences on gait, agility and cognitive outcomes. Small samples and methodological limitations resulted in low-certainty-evidence across outcomes. Conclusions: Apart from a suggestion that dance intervention modestly reduced motor disease severity and improved certain aspects of balance, there is insufficient evidence on all other outcomes, such as agility and motor function, cognitive, mood and social outcomes, quality of life as well as adverse events including the risk of fall. As evidence is insufficient to inform practice, evidence of benefits on motor disease severity and balance needs to be considered in the context of user-perception of benefit versus harm and acceptability in the development of practice guideline recommendations

    Knowledge of Signs and Symptoms of Heart Attack and Stroke among Singapore Residents

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    Aim. To determine the level of knowledge of signs and symptoms of heart attack and stroke in Singapore resident population, in comparison to the global community. Methods. A population based, random sample of 7,840 household addresses was selected from a validated national sampling frame. Each participant was asked eight questions on signs and symptoms of heart attack and 10 questions on stroke. Results. The response rate was 65.2% with 4,192 respondents. The level of knowledge for preselected, common signs and symptoms of heart attack and stroke was 57.8% and 57.1%, respectively. The respondents scored a mean of 5.0 (SD 2.4) out of 8 for heart attack, while they scored a mean of 6.8 (SD 2.9) out of 10 for stroke. Respondents who were ≥50 years, with lower educational level, and unemployed/retired had the least knowledge about both conditions. The level of knowledge of signs and symptoms of heart attack and stroke in Singapore is comparable to USA and Canada. Conclusion. We found a comparable knowledge of stroke and heart attack signs and symptoms in the community to countries within the same economic, educational, and healthcare strata. However older persons, those with lower educational level and those who are unemployed/retired, require more public health education efforts

    Germline variation at 8q24 and prostate cancer risk in men of European ancestry

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    Chromosome 8q24 is a susceptibility locus for multiple cancers, including prostate cancer. Here we combine genetic data across the 8q24 susceptibility region from 71,535 prostate cancer cases and 52,935 controls of European ancestry to define the overall contribution of germline variation at 8q24 to prostate cancer risk. We identify 12 independent risk signals for prostate cancer (p < 4.28 × 10−15), including three risk variants that have yet to be reported. From a polygenic risk score (PRS) model, derived to assess the cumulative effect of risk variants at 8q24, men in the top 1% of the PRS have a 4-fold (95%CI = 3.62–4.40) greater risk compared to the population average. These 12 variants account for ~25% of what can be currently explained of the familial risk of prostate cancer by known genetic risk factors. These findings highlight the overwhelming contribution of germline variation at 8q24 on prostate cancer risk which has implications for population risk stratification

    Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

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    Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

    Fine-mapping of prostate cancer susceptibility loci in a large meta-analysis identifies candidate causal variants

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    Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Peer reviewe
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