919 research outputs found

    Experimental Electronic Structure and Interband Nesting in BaVS_3

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    The correlated 3d sulphide BaVS_3 is a most interesting compound because of the apparent coexistence of one-dimensional and three-dimensional properties. Our experiments explain this puzzle and shed new light on its electronic structure. High-resolution angle-resolved photoemission measurements in a 4eV wide range below the Fermi level explored the coexistence of weakly correlated a_1g wide-band and strongly correlated e_g narrow-band d-electrons that is responsible for the complicated behavior of this material. The most relevant result is the evidence for a_1g--e_g inter-band nesting condition.Comment: 4 pages, 3 figure

    A study of the fine scale motions of incompressible time-developing mixing layers

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    This work is an extension of a project conducted at the previous CTR summer program and was reported by Chen et al. (1990). In that program, the geometry and topology of the dissipating motions in a variety of shear flows was examined. All data was produced by direct numerical simulations (DNS). The partial derivatives of the velocity field were determined at every grid point in the flow and various invariants and related quantities were computed from the velocity gradient tensor. Motions characterized by high rates of kinetic energy dissipation and high enstrophy were of particular interest. Scatter diagrams of the invariants were mapped out and interesting and unexpected patterns were seen. Each type of shear layer produced its own characteristic scatter plot. In the present project, attention is focused on the incompressible plane mixing layer, and the scatter diagrams are replaced with more useful joint probability density contours. Comparison of the topology of the dissipating motions of flows at different Reynolds numbers are made. Also, plane mixing layers at the same Reynolds number but with different initial conditions are compared

    Percutaneous transfemoral-transseptal implantation of a second-generation CardiAQ™ mitral valve bioprosthesis: first procedure description and 30-day follow-up

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    Transcatheter mitral valve implantation for mitral valve regurgitation is in the very early phase of development because of challenging anatomy and device dimensions. We describe the procedure of a transfemoral-transseptal implantation of the second-generation CardiAQ™ mitral valve bioprosthesis and 30-day follow-up

    ATscale – Establishing a Cross-Sector Partnership to Increase Access to Assistive Technology

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    Given existing gaps in access to Assistive Technology (AT) globally, it is important to think broadly and identify innovative approaches to overcome them. After an initial scoping in 2018, involving consultations and landscape analyses, ATscale, the Global Partnership for Assistive Technology was launched at the Global Disability Summit in July 2018 with the aim of reaching 500 million more people with life-changing AT by 2030. Applying lessons-learned from other areas of global health and development, ATscale was established with the recognition that to influence the complex systems for AT access, a broad set of stakeholders is needed to invest in and coordinate a multifaceted, systematic approach spanning market shaping, capacity development, and political prioritisation. Already, ATscale has demonstrated how a multi-sector group can come together and develop a cohesive strategy. This strategy overview has been released and shared broadly for additional consultation and feedback to further refine ATscale’s approach moving forward. ATscale has captured the attention of a diverse set of stakeholders. It now has eleven organisations within the Forming Committee and a broad community willing to inform its development. Now that it has been established, ATscale is working to move from an initial forming phase to a more formal organisation and to refine its operating model by late 2019 or early 2020. While there is significant momentum towards taking new, innovative approaches to address the gaps in access to quality, affordable AT for all, research shows that a wide range of systemic, underlying barriers and cross-cutting factors are contributing to the challenge in matching appropriate supply and demand for AT. While ATscale will address many of these, it is also going to require partnership on multiple levels with a coordinated strategic approach across a variety of stakeholders. This collective effort will enable the global community to have an impact greater than the sum of its individual parts in improving access to affordable, appropriate AT globally

    Outcome after heart-lung or lung transplantation in patients with Eisenmenger syndrome

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    Objective The optimal timing for transplantation is unclear in patients with Eisenmenger syndrome (ES). We investigated post-transplantation survival and transplantation-specific morbidity after heart-lung transplantation (HLTx) or lung transplantation (LTx) in a cohort of Nordic patients with ES to aid decision-making for scheduling transplantation. Methods We performed a retrospective, descriptive, population-based study of patients with ES who underwent transplantation from 1985 to 2012. Results Among 714 patients with ES in the Nordic region, 63 (9%) underwent transplantation. The median age at transplantation was 31.9 (IQR 21.1-42.3) years. Within 30 days after transplantation, seven patients (11%) died. The median survival was 12.0 (95% CI 7.6 to 16.4) years and the overall 1-year, 5-year, 10-year and 15-year survival rates were 84.1%, 69.7%, 55.8% and 40.6%, respectively. For patients alive 1 year post-transplantation, the median conditional survival was 14.8 years (95% CI 8.0 to 21.8), with 5-year, 10-year and 15-year survival rates of 83.3%, 67.2% and 50.0%, respectively. There was no difference in median survival after HLTx (n=57) and LTx (n=6) (14.9 vs 10.6 years, p=0.718). Median cardiac allograft vasculopathy, bronchiolitis obliterans syndrome and dialysis/kidney transplantation-free survival rates were 11.2 (95% CI 7.8 to 14.6), 6.9 (95% CI 2.6 to 11.1) and 11.2 (95% CI 8.8 to 13.7) years, respectively. The leading causes of death after the perioperative period were infection (36.7%), bronchiolitis obliterans syndrome (23.3%) and heart failure (13.3%). Conclusions This study shows that satisfactory post-transplantation survival, comparable with contemporary HTx and LTx data, without severe comorbidities such as cardiac allograft vasculopathy, bronchiolitis obliterans syndrome and dialysis, is achievable in patients with ES, with a conditional survival of nearly 15 years.Peer reviewe

    Combined and single effects of pesticide carbaryl and toxic Microcystis aeruginosa on the life history of Daphnia pulicaria

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    The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different, sub-lethal concentrations (chronic exposure). In order to determine the actual carbaryl concentrations in the water LC–MS/MS was used. For analyses of the cyanotoxin concentration in Daphnia’s body enzyme-linked immunosorbent assay (ELISA) was used. Individual daphnids were cultured in a flow-through system under constant light (16 h of light: 8 h of dark), temperature (20°C), and food conditions (Scenedesmus obliquus, 1 mg of C l−1). The results showed that in the treatments with carbaryl egg numbers per female did not differ significantly from controls, but the mortality of newborns increased significantly. Increasing microcystin concentrations significantly delayed maturation, reduced size at first reproduction, number of eggs, and newborns. The interaction between carbaryl and Microcystis was highly significant. Animals matured later and at a smaller size than in controls. The number of eggs per female was reduced as well. Moreover, combined stressors caused frequent premature delivery of offspring with body deformations such as dented carapax or an undeveloped heart. This effect is concluded to be synergistic and could not be predicted from the effects of the single stressors.

    The Kinematic Algebra From the Self-Dual Sector

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    We identify a diffeomorphism Lie algebra in the self-dual sector of Yang-Mills theory, and show that it determines the kinematic numerators of tree-level MHV amplitudes in the full theory. These amplitudes can be computed off-shell from Feynman diagrams with only cubic vertices, which are dressed with the structure constants of both the Yang-Mills colour algebra and the diffeomorphism algebra. Therefore, the latter algebra is the dual of the colour algebra, in the sense suggested by the work of Bern, Carrasco and Johansson. We further study perturbative gravity, both in the self-dual and in the MHV sectors, finding that the kinematic numerators of the theory are the BCJ squares of the Yang-Mills numerators.Comment: 29 pages, 5 figures. v2: references added, published versio

    Catheter-based intervention for symptomatic patient with severe mitral regurgitation and very poor left ventricular systolic function - Safe but no room for complacency

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    Many patients with left ventricular systolic dysfunction have concomitant mitral regurgitation (MR). Their symptoms and prognosis worsen with increasing severity of MR. Percutaneous MitraClip((R)) can be used safely to reduce the severity of MR even in patients with advanced heart failure and is associated with improved symptoms, quality of life and exercise tolerance. However, a few patients with very poor left ventricular systolic function may experience significant haemodynamic disturbance in the peri-procedural period. We present three such patients, highlighting some of the potential problems encountered and discuss their possible pathophysiological mechanisms and safety measures.published_or_final_versio
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