298 research outputs found

    Persistent Atrial Fibrillation: The Role of Left Atrial Posterior Wall Isolation and Ablation Strategies.

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    Atrial fibrillation (AF) is a global disease with rapidly rising incidence and prevalence. It is associated with a higher risk of stroke, dementia, cognitive decline, sudden and cardiovascular death, heart failure and impairment in quality of life. The disease is a major burden on the healthcare system. Paroxysmal AF is typically managed with medications or endocardial catheter ablation to good effect. However, a large proportion of patients with AF have persistent or long-standing persistent AF, which are more complex forms of the condition and thus more difficult to treat. This is in part due to the progressive electro-anatomical changes that occur with AF persistence and the spread of arrhythmogenic triggers and substrates outside of the pulmonary veins. The posterior wall of the left atrium is a common site for these changes and has become a target of ablation strategies to treat these more resistant forms of AF. In this review, we discuss the role of the posterior left atrial wall in persistent and long-standing persistent AF, the limitations of current endocardial-focused treatment strategies, and future perspectives on hybrid epicardial-endocardial approaches to posterior wall isolation or ablation

    Web Document Clustering Using Document Index Graph

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    Document Clustering is an important tool for many Information Retrieval (IR) tasks. The huge increase in amount of information present on web poses new challenges in clustering regarding to underlying data model and nature of clustering algorithm. Document clustering techniques mostly rely on single term analysis of document data set. To achieve more accurate document clustering, more informative feature such as phrases are important in this scenario. Hence first part of the paper presents phrase-based model, Document Index Graph (DIG), which allows incremental phrase-based encoding of documents and efficient phrase matching. It emphasizes on effectiveness of phrase-based similarity measure over traditional single term based similarities. In the second part, a Document Index Graph based Clustering (DIGBC) algorithm is proposed to enhance the DIG model for incremental and soft clustering. This algorithm incrementally clusters documents based on proposed clusterdocument similarity measure. It allows assignment of a document to more than one cluster. The DIGBC algorithm is more efficient as compared to existing clustering algorithms such as single pass, K-NN and Hierarchical Agglomerative Clustering (HAC) algorithm

    The shape of equality: discourses around the Section 28 repeal in Scotland

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    This article focuses on conceptualizations of equality in the discourses deployed in the campaign to repeal Section 28 in Scotland. I use the parliamentary debates and two newspapers: the Daily Record, which supported the campaign to Keep the Clause, and The Guardian, which supported repeal, to exemplify the different discursive articulations around equality and citizenship. I suggest that the Scottish example provides further evidence of the ways in which liberalism naturalizes heterosexuality as the standard for citizenship and thus bequeaths a hierarchy of 'equality' and citizenship in the realm of sexuality, wherein lesbian and gay citizenship is either rendered invalid or characterized as 'special rights'. However, within the narrow confines of the parliamentary debates, more expansive and differentiated notions of citizenship and equality are evident. Whilst I conclude that the 'shape' of equality achieved through the repeal has been moulded to support institutionalized heterosexuality - with Section 28 replaced by statutory guidelines on sex education which advocate marriage - I also suggest equality is contested, both through the recognition of transformations in heterosexual family forms and the appeal to non-discrimination as a democratic principle. It is possible, therefore, that current destabilizations of the heterosexual social order simultaneously destabilize the precepts of liberal democracy

    Thermodynamic properties and structural stability of thorium dioxide

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    Using density functional theory (DFT) calculations, we have systematically investigated the thermodynamic properties and structural stabilities of thorium dioxide (ThO2_2). Based on the calculated phonon dispersion curves, we calculate the thermal expansion coefficient, bulk modulus, and heat capacities at different temperatures for ThO2_2 under the quasi-harmonic approximation. All the results are in good agreement with corresponding experiments proving the validity of our methods. Our theoretical studies can help people more clearly understand the thermodynamic behaviors of ThO2_2 at different temperatures. In addition, we have also studied possible defect formations and diffusion behaviors of helium in ThO2_2, to discuss its structural stability. It is found that in intrinsic ThO2_2 without any Fermi energy shifts, the interstitial Thi4+_i^{4+} defect other than oxygen or thorium vacancies, interstitial oxygen, and any kinds of Frenkel pairs, is most probable to form with an energy release of 1.74 eV. However, after upshifting the Fermi energy, the formation of the other defects also becomes possible. For helium diffusion, we find that only through the thorium vacancy can it happen with the small energy barrier of 0.52 eV. Otherwise, helium atoms can hardly incorporate or diffuse in ThO2_2. Our results indicate that people should prevent upshifts of the Fermi energy of ThO2_2 to avoid the formation of thorium vacancies and so as to prevent helium caused damages.Comment: 11 pages, 11 figure

    Yield sensing technologies for perennial and annual horticultural crops: a review

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    Yield maps provide a detailed account of crop production and potential revenue of a farm. This level of details enables a range of possibilities from improving input management, conducting on-farm experimentation, or generating profitability map, thus creating value for farmers. While this technology is widely available for field crops such as maize, soybean and grain, few yield sensing systems exist for horticultural crops such as berries, field vegetable or orchards. Nevertheless, a wide range of techniques and technologies have been investigated as potential means of sensing crop yield for horticultural crops. This paper reviews yield monitoring approaches that can be divided into proximal, either direct or indirect, and remote measurement principles. It reviews remote sensing as a way to estimate and forecast yield prior to harvest. For each approach, basic principles are explained as well as examples of application in horticultural crops and success rate. The different approaches provide whether a deterministic (direct measurement of weight for instance) or an empirical (capacitance measurements correlated to weight for instance) result, which may impact transferability. The discussion also covers the level of precision required for different tasks and the trend and future perspectives. This review demonstrated the need for more commercial solutions to map yield of horticultural crops. It also showed that several approaches have demonstrated high success rate and that combining technologies may be the best way to provide enough accuracy and robustness for future commercial systems

    Association of Plasma CD163 Concentration with De Novo–Onset Chronic Graft-versus-Host Disease

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    Chronic graft-versus-host disease (GVHD) is the leading cause of long-term morbidity and mortality after allogeneic hematopoietic cell transplantation. To identify prognostic plasma proteins associated with de novo– or quiescent-onset chronic GVHD (cGVHD), we performed a discovery and validation proteomic study. The total study cohort included 167 consecutive patients who had no clinical evidence of GVHD under minimum glucocorticoid administration and had available plasma samples obtained at 80 ± 14 days after transplantation. We first used high-throughput mass spectrometry to screen pooled plasma using 20 cases with subsequent cGVHD and 20 controls without it, and we identified 20 candidate proteins. We then measured 12 of the 20 candidate proteins by ELISA on the same individual samples and identified 4 proteins for further verification (LGALS3BP, CD5L, CD163, and TXN for de novo onset, and LGALS3BP and CD5L for quiescent onset). The verification cohort included 127 remaining patients. The cumulative incidence of de novo–onset cGVHD was higher in patients with higher plasma soluble CD163 concentrations at day 80 than those with lower concentrations (75% versus 40%, P = .018). The cumulative incidence of de novo– or quiescent-onset cGVHD did not differ statistically according to concentrations of the 3 other proteins at day 80. CD163 is a macrophage scavenger receptor and is elevated in oxidative conditions. These results suggest that monocyte or macrophage activation or increased oxidative stress may contribute to the pathogenesis of cGVHD

    Global respiratory syncytial virus-related infant community deaths

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    Background: Respiratory syncytial virus (RSV) is a leading cause of pediatric death, with \u3e99% of mortality occurring in low- and lower middle-income countries. At least half of RSV-related deaths are estimated to occur in the community, but clinical characteristics of this group of children remain poorly characterized.Methods: The RSV Global Online Mortality Database (RSV GOLD), a global registry of under-5 children who have died with RSV-related illness, describes clinical characteristics of children dying of RSV through global data sharing. RSV GOLD acts as a collaborative platform for global deaths, including community mortality studies described in this supplement. We aimed to compare the age distribution of infant deaths \u3c6 months occurring in the community with in-hospital.Results: We studied 829 RSV-related deaths \u3c1 year of age from 38 developing countries, including 166 community deaths from 12 countries. There were 629 deaths that occurred \u3c6 months, of which 156 (25%) occurred in the community. Among infants who died before 6 months of age, median age at death in the community (1.5 months; IQR: 0.8-3.3) was lower than in-hospital (2.4 months; IQR: 1.5-4.0; P \u3c .0001). The proportion of neonatal deaths was higher in the community (29%, 46/156) than in-hospital (12%, 57/473, P \u3c 0.0001).Conclusions: We observed that children in the community die at a younger age. We expect that maternal vaccination or immunoprophylaxis against RSV will have a larger impact on RSV-related mortality in the community than in-hospital. This case series of RSV-related community deaths, made possible through global data sharing, allowed us to assess the potential impact of future RSV vaccines

    The Impact of the COVID-19 Pandemic on Racial Disparities in Patients Undergoing Total Shoulder Arthroplasty in the United States

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    INTRODUCTION: The purpose of this study was to assess racial disparities in total shoulder arthroplasty (TSA) in the US and to determine whether these disparities were affected by the COVID-19 pandemic. METHODS: Centers for Medicare and Medicaid Services (CMS) 100% sample was used to examine primary TSA volume from April-December from 2019-2020. Utilization was assessed for White/Black/Hispanic/Asian populations to determine if COVID-19 affected these groups differently. A regression model adjusted for age/sex/CMS-Hierarchical Condition Categories (HCC) score, dual enrollment (proxy for socioeconomic status), time fixed effects, and Core-based Statistical Area (CBSA) fixed effects was used to study difference across groups. RESULTS: In 2019, TSA volume/1000 beneficiaries was 1.51 for White and 0.57 for non-White, a 2.6-fold difference. In 2020, the rate of TSA in White patients (1.30/1000) was 2.9 times higher than non-White (0.45/1000) during the COVID-19 pandemic (P\u3c0.01). There was an overall 14% decrease in TSA volume/1000 Medicare beneficiaries in 2020; non-White patients had a larger percentage decrease in TSA volume than White (21% vs. 14%, estimated difference;8.7%,p = 0.02). Black patients experienced the most pronounced disparity with estimated difference of 10.1%,p = 0.05, compared with White patients. Similar disparities were observed when categorizing procedures into anatomic and reverse TSA, but not proximal humerus fracture. CONCLUSIONS: During the COVID-19 pandemic, overall TSA utilization decreased by 14% with White patients experiencing a decrease of 14%, and non-White patients experiencing a decrease of 21%. This trend was observed for elective TSA while disparities were less apparent for proximal humerus fracture
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