79 research outputs found

    The 'reach' of Digital Language Archives: towards criteria for evaluation

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    Over the last decade, and with the help of digital media and technologies, archives (with the focus here on archives for endangered and minority languages) have extended their focus from preservation to also becoming facilities for dissemination. Their innovations have largely been on ‘discovery’: firstly by encouraging digitisation and inclusion of analogue and obscure materials, and by partnership with funding institutions to support the creation of new, ‘born digital’ language resources; and secondly through online provision of language resources via web catalogues driven by standardised metadata and in some cases providing enhanced discovery through web portals aggregating the holdings of multiple archives. These advances have increased the visibility, relevance and authority of archives for language-related disciplines and for language-speaker communities. This paper considers a broader set of parameters describing the ‘reach’ of archives, where ‘reach’ includes (a) archives’ understanding of their key audiences in order to provide appropriate services for them, e.g. identifying a range of relevant audiences, their languages of access, their varied technological and information literacies, interface design and usability; (b) discovery, drawing on the understandings of audiences in order to help them browse, navigate, search, identify and select their items of interest; (c) delivery, i.e. making available selected resources according to users’ preferences whether by download, view-in-browser, through apps or other means; (d) access management such that resource delivery follows depositors’ and communities’ preferences, and where users have ways of applying for and negotiating for access; (e) information accessibility, where the actual desired content is accessible to users, whether in terms of contextualisation or appropriate complexity, language, or modality; and finally (f) feedback channels, where users can utilise the archive to provide feedback to depositors or to enhance deposits with user-generated content. Through considering how a number of archives are providing such services, we can see their transition from repositories of memory to facilities for fostering participation and understanding

    Urgent bedreigde typische soorten en vegetatietypen van Natura 2000-habitattypen

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    Dit rapport is de weerslag van een onderzoek naar de urgent bedreigde en potentieel urgent bedreigde typische soorten en de urgent bedreigde en potentieel urgent bedreigde vegetatietypen van de habitattypen van de Natura 2000-gebieden. In totaal zijn 67 typische soorten als Urgent Bedreigd gecategoriseerd; nog eens 26 soorten zijn gecategoriseerd als Potentieel Urgent Bedreigd. Voor de vegetatietypen geldt dat er 15 (sub)associaties Urgent bedreigd zijn. Op een bijbehorende cdrom wordt voor al deze soorten en vegetaties de huidige verspreiding gegeven, of herstel binnen of buiten Natura 2000 zou moeten plaatsvinden, wat de knelpunten hierbij zijn en waar de beste herstellocaties gelegen zijn

    Low agreement between cardiologists diagnosing left ventricular hypertrophy in children with end-stage renal disease

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    Background: Monitoring of the appearance of left ventricular hypertrophy (LVH) by echocardiography is currently recommended for in the management of children with End-stage renal disease (ESRD). In order to investigate the validity of this method in ESRD children, we assessed the intra- and inter-observer reproducibility of the diagnosis LVH. Methods. Echocardiographic measurements in 92 children (0-18 years) with ESRD, made by original analysists, were reassessed offline, twice, by 3 independent observers. Smallest detectable changes (SDC) were calculated for continuous measurements of diastolic interventricular septum (IVSd), Left ventricle posterior wall thickness (LVPWd), Left ventricle end-diastolic diameter (LVEDd), and Left ventricle mass index (LVMI). Cohen's kappa was calculated to assess the reproducibility of LVH defined in two different ways. LVHWT was defined as Z-value of IVSd and/or LVPWd>2 and LVHMI was defined as LVMI> 103 g/m 2 for boys and >84 g/m2 for girls. Results: The intra-observer SDCs ranged from 1.6 to 1.7 mm, 2.0 to 2.6 mm and 17.7 to 30.5 g/m2 for IVSd, LVPWd and LVMI, respectively. The inter-observer SDCs were 2.6 mm, 2.9 mm and 24.6 g/m2 for IVSd, LVPWd and LVMI, respectively. Depending on the observer, the prevalence of LVHWT and LVHMI ranged from 2 to 30% and from 8 to 25%, respectively. Kappas ranged from 0.4 to 1.0 and from 0.1 to 0.5, for intra-and inter- observer reproducibility, respectively. Conclusions: Changes in diastolic wall thickness of less than 1.6 mm or LVMI less than 17.7 g/m2 cannot be distinguished from measurement error in individual children, even when measured by the same observer. This limits the use of echocardiography to detect changes in wall thickness in children with ESRD in routine practice

    3-Month enalapril treatment in pediatric fontan patients with moderate to good systolic ventricular function

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    Many Fontan patients with and without systolic ventricular dysfunction are being treated with angiotensin-converting enzyme (ACE) inhibitors, despite its effectiveness remaining unclear. In the present study, we evaluated the short-term effect of enalapril on exercise capacity, vascular and ventricular function in pediatric Fontan patients with moderategood systolic ventricular function. Fontan patients between 8 and 18 years with moderategood systolic ventricular function and without previous ACE inhibitor treatment were included and were treated with enalapril for 3 months. During the first 2 weeks, the dosage was titrated according to systolic blood pressure (SBP). Exercise tests, ventricular function assessed by echocardiography, arterial stiffness measurements, and plasma levels of N-terminal pro-B-type natriuretic peptide assessed before and after a 3-month enalapril treatment period was compared. A total of 28 Fontan patients (median age 13.9 years, 6 to 15 years after Fontan operation) completed the study with a mean dosage of 0.3 +/- 0.1 mg/ kg/d. A total of 6 patients (21 %) experienced a significant drop in SBP and 6 others (21%) experienced other adverse events. Enalapril treatment lowered the SBP (from 110 to 104 mmHg, p = 0.003) and levels of N-terminal pro-B-type natriuretic peptide (from 80 to 72 ng/L, p = 0.036). However, enalapril treatment did not improve exercise capacity, ventricular function, or arterial stiffness. In conclusion, short-term ACE inhibition has no beneficial effect in Fontan patients with moderate-good systolic ventricular function. (C) 2021 The Authors. Published by Elsevier Inc.Thoracic Surger

    Long-term outcome after the arterial switch operation: 43 years of experience

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    OBJECTIVES: The objective of this study was to assess our 43-year experience with arterial switch operation (ASO) for transposition of the great arteries (TGA) by analysing cardiac outcome measures (hospital and late mortality, reoperations and catheter interventions, significant coronary artery obstruction) and to identify risk factors for reoperation and catheter interventions.METHODS: A total of 490 patients who underwent ASO for TGA from 1977 to 2020 were included in this retrospective, single-centre study. Data on reoperation and catheter intervention of hospital survivors were estimated by the Kaplan-Meier method and compared using a long-rank test. Risk factors for reoperation and/or catheter intervention were assessed by multivariate Cox regression analysis.RESULTS: Hospital mortality occurred in 43 patients (8.8%), late death in 12 patients (2.9%) and 43 patients were lost to follow-up. Median follow-up time of 413 hospital survivors was 15.6 (interquartile range 7.0-22.4) years. Reoperations were performed in 83 patients (117 reoperations). Neoaortic valve regurgitation with root dilatation was the second most common indication for reoperation (15/83 patients, 18.1%) after right ventricular outflow tract obstruction (50/83 patients, 60.2%). Risk factors for any reoperation on multivariable analysis were: TGA morphological subtype [TGA with ventricular septal defect: hazard ratio (HR)=1.99, 95% confidence interval (CI) 1.18-3.36; P=0.010 and Taussig-Bing: HR=2.17, 95% CI 1.02-4.64; P=0.045], aortic arch repair associated with ASO (HR=3.03, 95% CI 1.62-5.69; P=0.001) and a non-usual coronary artery anatomy (HR=2.41, 95% CI 1.45-4.00; P=0.001). One hundred and one catheter interventions were performed in 54 patients, usually for relief of supravalvular pulmonary stenosis (44/54 patients, 81.5%) or arch obstruction (10/54 patients, 18.5%). Main risk factor for catheter intervention on multivariable analysis was aortic arch repair associated with ASO (HR=2.95, 95% CI 1.37-6.36; P=0.006). Significant coronary artery stenosis was relatively uncommon (9/413 patients, 2.2%) but may be underrepresented.CONCLUSIONS: Patients after ASO typically have good long-term clinical outcomes but reoperations and interventions remain necessary in some patients. Neoaortic valve regurgitation with root dilatation is the second most common indication for reoperation after right ventricular outflow tract obstruction and an increasing need for neoaortic valve and root redo surgery in future is to be expected.Cardiolog

    Determinants of exercise limitation in contemporary paediatric Fontan patients with an extra cardiac conduit

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    Background: Although various determinants of exercise limitation in Fontan patients have been studied, most research has been performed in patients who underwent different surgical procedures with differing haemodynamic characteristics. The aim of the current study was to evaluate non-invasively measured cardiovascular parameters and their influence on exercise performance in paediatric Fontan patients with an extracardiac conduit and moderate-good systolic ventricular function. Methods: Fontan patients, between 8 and 18 years of age, with moderate to good systolic ventricular function and an extracardiac conduit were included. Exercise performance and cardiovascular assessment, comprising echocardiography, aortic stiffness measurement and ambulatory measurement of cardiac autonomous nervous activity were performed on the same day. Healthy subjects served as controls. Results: Thirty-six Fontan patients (age 14.0 years) and thirty-five healthy subjects (age 12.8 years) were included. Compared to controls, Fontan patients had reduced diastolic ventricular function and increased arterial stiffness. No differences were found in heart rate (HR) and cardiac parasympathetic nervous activity. In Fontan patients, maximal as well as submaximal exercise capacity was impaired, with the percentage of predicted capacity ranging between 54 and 72%. Chronotropic competence, however, was good with a peak HR of 174 (94% of predicted). Lower maximal and submaximal exercise capacity was correlated with a higher HR at rest, higher pulse wave velocity of the aorta and a lower ratio of early and late diastolic flow velocity. Conclusion: Contemporary paediatric Fontan patients have an impaired exercise capacity with preserved chronotropic competence. Exercise performance correlates with heart rate at rest, diastolic function and aortic stiffness.Developmen

    Atrial function in Fontan patients assessed by CMR: Relation with exercise capacity and long-term outcomes

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    Objective: To assess the role of atrial function on exercise capacity and clinical events in Fontan patients. Design: We included 96 Fontan patients from 6 tertiary centers, aged 12.8 (IQR 10.1–15.6) years, who underwent cardiac magnetic resonance imaging and cardiopulmonary exercise testing within 12 months of each other from 2004 to 2017. Intra-atrial lateral tunnel (ILT) and extracardiac conduit (ECC) patients were matched 1:1 with regard to age, gender and dominant ventricle. The pulmonary venous atrium was manually segmented in all phases and slices. Atrial function was assessed by volume-time curves. Furthermore, atrial longitudinal and circumferential feature tracking strain was assessed. We determined the relation between atrial function and exercise capacity, assessed by peak oxygen uptake and VE/VCO2 slope, and events (mortality, listing for transplant, re-intervention, arrhythmia) during follow-up. Results: Atrial maximal and minimal volumes did not differ between ILT and ECC patients. ECC patients had higher reservoir function (21.1 [16.4–28.0]% vs 18.2 [10.9–22.2]%, p = .03), lower conduit function and lower total circumferential strain (13.8 ± 5.1% vs 18.0 ± 8.7%, p = .01), compared to ILT patients. Only for ECC patients, a better late peak circumferential strain rate predicted better VE/VCO2 slope. No other parameter of atrial function predicted peak oxygen uptake or VE/VCO2 slope. During a median follow-up of 6.2 years,

    The effect of electro-anatomical mapping on the success rate and fluoroscopy time in supra-ventricular tachycardia ablation in children: single centre retrospective study

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    Aims: To evaluate the effect of electro-anatomical mapping on success rate and fluoroscopy time in ablation of supraventricular tachycardia substrates in a large group of children. Methods: Patients referred from multiple centres in the Netherlands and who received a first ablation for supraventricular tachycardia substrates in the Leiden University Medical Center between 2014 and 2020 were included in this retrospective cohort study. They were divided in procedures in patients with fluoroscopy and procedures in patients using electro-anatomical mapping. Results: Outcomes of ablation of 373 electro-anatomical substrates were analysed. Acute success rate in the fluoro-group (n = 170) was 95.9% compared to 94.5% in the electro-anatomical mapping group (n = 181) (p = 0.539); recurrence rate was 6.1% in the fluoro-group and 6.4% in the electro-anatomical mapping group (p = 0.911) after a 12-months follow-up. Redo-ablations were performed in 12 cases in the fluoro-group and 10 cases in the electro-anatomical mapping group, with a success rate of 83.3% versus 80.0%, resulting in an overall success rate of 95.9% in the fluoro-group and 92.8% in the electro-anatomical mapping group (p = 0.216) after 12 months. Fluoroscopy time and dose area product decreased significantly from 16.00 +/- 17.75 minutes (median +/- interquartile range) to 2.00 +/- 3.00 minutes (p = 0.000) and 210.5 mu Gym(2) +/- 249.3 to 32.9 mu Gym(2) +/- 78.6 (p = 0.000), respectively. In the fluoro-group, four complications occurred (2.0%) and in the electro-anatomical mapping group no complications occurred. Conclusion: These results demonstrate that ablations of supra-ventricular tachycardia substrates in children remain a highly effective and safe treatment after the introduction of electro-anatomical mapping as a standard of care, while significantly reducing fluoroscopy time and dose area product.Developmen
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