405 research outputs found

    The role of long-term mechanical circulatory support in patients with advanced heart failure

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    In patients with end-stage heart failure, advanced therapies such as heart transplantation and long-term mechanical circulatory support (MCS) with a left ventricular assist device (LVAD) have to be considered. LVADs can be implanted as a bridge to transplantation or as an alternative to heart transplantation: destination therapy. In the Netherlands, long-term LVAD therapy is gaining importance as a result of increased prevalence of heart failure together with a low number of heart transplantations due to shortage of donor hearts. As a result, the difference between bridge to transplantation and destination therapy is becoming more artificial since, at present, most patients initially implanted as bridge to transplantation end up receiving extended LVAD therapy. Following LVAD implantation, survival after 1, 2 and 3 years is 83%, 76% and 70%, respectively. Quality of life improves substantially despite important adverse events such as device-related infection, stroke, major bleeding and right heart failure. Early referral of potential candidates for long-term MCS is of utmost importance and positively influences outcome. In this review, an overview of the indications, contraindications, patient selection, clinical outcome and optimal time of referral for long-term MCS is given

    The positive predictive value of asymmetrical skin creases in the diagnosis of pathological developmental dysplasia of the hip

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    Aims The aim of this study was to identify the association between asymmetrical skin creases of the thigh, buttock or inguinal region and pathological developmental dysplasia of the hip (DDH). Patients and Methods Between 1 January 1996 and 31 December 2016, all patients referred to our unit from primary or secondary care with risk factors for DDH were assessed in a “one stop” clinic. All had clinical and sonographic assessment by the senior author (RWP) with the results being recorded prospectively. The inclusion criteria for this study were babies and children referred with asymmetrical skin creases. Those with a neurological cause of DDH were excluded. The positive predictive value (PPV) for pathological DDH was calculated. Results A total of 105 patients met the inclusion criteria. There were 71 girls and 34 boys. Only two were found to have pathological DDH. Both also had unilateral limited abduction of the hip in flexion and a positive Galeazzi sign with apparent leg-length discrepancy. Thus, if the specialist examination of a patient with asymmetrical skin creases was normal, the PPV for DDH was 0%. Conclusion Isolated asymmetrical skin creases are an unreliable clinical sign in the diagnosis of pathological DDH. Greater emphasis should be placed on the presence of additional clinical signs to guide radiological screening in babies and children

    Characterization of atrial arrhythmias following mitral valve repair: incidence and risk factors

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    Objectives This study aims to investigate the occurrence, type and correlation of early and late atrial arrhythmias following mitral valve repair in patients with no preoperative history of atrial arrhythmias. Methods Patients undergoing mitral valve (MV) repair for degenerative disease were included. Early and late postoperative electrocardiograms were evaluated for the incidence and type of atrial arrhythmia (atrial fibrillation [AF] or atrial tachycardia [AT]). Results The 192 patients were included. Early atrial arrhythmias occurred in 100/192 (52.1%) patients; AF in 61 (31.8%) patients, early AT in 15 (7.8%) and both in 24 (12.5%). In total 89% of patients were discharged in sinus rhythm. During a follow-up time of 7.3 years, 14 patients (7.3%) died and 49 (25.5%) patients developed late atrial arrhythmias. At 10 years, the cumulative incidence of any late atrial arrhythmia, with death as competing risk, was 64% (95% confidence interval [CI] = 55%–72%). On Fine-Gray model analysis, only early postoperative AF lasting >24 h was related to the development of late AF (hazard ratio 5.99, 95% CI = 1.78%–20.10%, p = .004). Early postoperative ATs were related to the development of late tachycardias, independent of their duration (24 h hazard ratio 3.51, 95% CI = 1.65–7.46, p = .001). Conclusions Early and late atrial arrhythmias were common after MV repair surgery. Only early postoperative AF lasting >24 h was a risk factor for the occurrence of late AF. Conversely, any postoperative AT was correlated to the development of late ATs

    The use of design activity for research into Computer Supported Co-operative Working (CSCW)

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    This paper describes current research at Loughborough University in the field of Computer Supported Co-operative Working (CSCW). The project, which is funded by the Information Engineering Directorate (IED) within the Science and Engineering Research Council (SERC), is titled 'Establishing the Communicational Requirements of Information Technology (IT) Systems that Support Humans Co-operating Remotely'. The research group have adopted a less cumbersome acronym for the project - ROCOCO which is derived from REmote COoperation and COmmunication. Design activity has been proposed as offering a suitable context for a study of co-operation and at the time of writing the first phase of the experiments - involving face to face or proximal co-operation - has been undertaken and the analysis begun. The ROCOCO project is about to embark on phase two involving remote co-operation. This paper presents, in some detail, the construction and operation of a pilot study that allowed project members to assess and adjust the experimental design prior to the start of Phase One. A selection of initial findings illustrate the nature of the investigation to be undertaken. The paper also seeks to highlight the importance of CSCW research for the design community. The substance of the paper is concerned with a presentation of issues involved in an analysis of co-operation, involving as it does, verbal and non-verbal communication

    Do adults with high functioning autism or Asperger Syndrome differ in empathy and emotion recognition?

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    The present study examined whether adults with high functioning autism (HFA) showed greater difficulties in (i) their self-reported ability to empathise with others and/or (ii) their ability to read mental states in others’ eyes than adults with Asperger syndrome (AS). The Empathy Quotient (EQ) and ‘Reading the Mind in the Eyes’ Test (Eyes Test) were compared in 43 adults with AS and 43 adults with HFA. No significant difference was observed on EQ score between groups, while adults with AS performed significantly better on the Eyes Test than those with HFA. This suggests that adults with HFA may need more support, particularly in mentalizing and complex emotion recognition, and raises questions about the existence of subgroups within autism spectrum conditions

    Multi-Jet Event Rates in Deep Inelastic Scattering and Determination of the Strong Coupling Constant

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    Jet event rates in deep inelastic ep scattering at HERA are investigated applying the modified JADE jet algorithm. The analysis uses data taken with the H1 detector in 1994 and 1995. The data are corrected for detector and hadronization effects and then compared with perturbative QCD predictions using next-to-leading order calculations. The strong coupling constant alpha_S(M_Z^2) is determined evaluating the jet event rates. Values of alpha_S(Q^2) are extracted in four different bins of the negative squared momentum transfer~\qq in the range from 40 GeV2 to 4000 GeV2. A combined fit of the renormalization group equation to these several alpha_S(Q^2) values results in alpha_S(M_Z^2) = 0.117+-0.003(stat)+0.009-0.013(syst)+0.006(jet algorithm).Comment: 17 pages, 4 figures, 3 tables, this version to appear in Eur. Phys. J.; it replaces first posted hep-ex/9807019 which had incorrect figure 4

    Multiplicity Structure of the Hadronic Final State in Diffractive Deep-Inelastic Scattering at HERA

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    The multiplicity structure of the hadronic system X produced in deep-inelastic processes at HERA of the type ep -> eXY, where Y is a hadronic system with mass M_Y< 1.6 GeV and where the squared momentum transfer at the pY vertex, t, is limited to |t|<1 GeV^2, is studied as a function of the invariant mass M_X of the system X. Results are presented on multiplicity distributions and multiplicity moments, rapidity spectra and forward-backward correlations in the centre-of-mass system of X. The data are compared to results in e+e- annihilation, fixed-target lepton-nucleon collisions, hadro-produced diffractive final states and to non-diffractive hadron-hadron collisions. The comparison suggests a production mechanism of virtual photon dissociation which involves a mixture of partonic states and a significant gluon content. The data are well described by a model, based on a QCD-Regge analysis of the diffractive structure function, which assumes a large hard gluonic component of the colourless exchange at low Q^2. A model with soft colour interactions is also successful.Comment: 22 pages, 4 figures, submitted to Eur. Phys. J., error in first submission - omitted bibliograph

    Differential (2+1) Jet Event Rates and Determination of alpha_s in Deep Inelastic Scattering at HERA

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    Events with a (2+1) jet topology in deep-inelastic scattering at HERA are studied in the kinematic range 200 < Q^2< 10,000 GeV^2. The rate of (2+1) jet events has been determined with the modified JADE jet algorithm as a function of the jet resolution parameter and is compared with the predictions of Monte Carlo models. In addition, the event rate is corrected for both hadronization and detector effects and is compared with next-to-leading order QCD calculations. A value of the strong coupling constant of alpha_s(M_Z^2)= 0.118+- 0.002 (stat.)^(+0.007)_(-0.008) (syst.)^(+0.007)_(-0.006) (theory) is extracted. The systematic error includes uncertainties in the calorimeter energy calibration, in the description of the data by current Monte Carlo models, and in the knowledge of the parton densities. The theoretical error is dominated by the renormalization scale ambiguity.Comment: 25 pages, 6 figures, 3 tables, submitted to Eur. Phys.

    Measurements of Transverse Energy Flow in Deep-Inelastic Scattering at HERA

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    Measurements of transverse energy flow are presented for neutral current deep-inelastic scattering events produced in positron-proton collisions at HERA. The kinematic range covers squared momentum transfers Q^2 from 3.2 to 2,200 GeV^2, the Bjorken scaling variable x from 8.10^{-5} to 0.11 and the hadronic mass W from 66 to 233 GeV. The transverse energy flow is measured in the hadronic centre of mass frame and is studied as a function of Q^2, x, W and pseudorapidity. A comparison is made with QCD based models. The behaviour of the mean transverse energy in the central pseudorapidity region and an interval corresponding to the photon fragmentation region are analysed as a function of Q^2 and W.Comment: 26 pages, 8 figures, submitted to Eur. Phys.

    Low Q^2 Jet Production at HERA and Virtual Photon Structure

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    The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure
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