381 research outputs found

    Helping young designers design for children: evaluating toys and possible values

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    When designing for children, it remains important not only to emphasise elements such as ergonomics and usability but also values, that can be translated into pleasurable user experiences for children. While methods such as interviews are commonly used to better understand our users, interviewing children can be a challenge. Experience as part of a year project on designing toys for children highlighted that children might answer questions in a surprising way, or students might struggle to ask questions that are not suggestive. To overcome some of these difficulties, we developed a Value Matrix, that can help students to explore the various values or incentives children might have while playing. This Value Matrix can subsequently be used to scan existing toys or new concepts and translate these insights into toys that consist of a wider variety of values children like to experience in a game or toy. We evaluated this tool with 118 first year Industrial Product Design students. Our results show that the Value Matrix gives students guidance and support while designing

    Directed networks as a novel way to describe and analyze cardiac excitation : directed graph mapping

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    Networks provide a powerful methodology with applications in a variety of biological, technological and social systems such as analysis of brain data, social networks, internet search engine algorithms, etc. To date, directed networks have not yet been applied to characterize the excitation of the human heart. In clinical practice, cardiac excitation is recorded by multiple discrete electrodes. During (normal) sinus rhythm or during cardiac arrhythmias, successive excitation connects neighboring electrodes, resulting in their own unique directed network. This in theory makes it a perfect fit for directed network analysis. In this study, we applied directed networks to the heart in order to describe and characterize cardiac arrhythmias. Proof-of-principle was established using in-silico and clinical data. We demonstrated that tools used in network theory analysis allow determination of the mechanism and location of certain cardiac arrhythmias. We show that the robustness of this approach can potentially exceed the existing state-of-the art methodology used in clinics. Furthermore, implementation of these techniques in daily practice can improve the accuracy and speed of cardiac arrhythmia analysis. It may also provide novel insights in arrhythmias that are still incompletely understood

    Feasibility and performance of a device for automatic self-detection of symptomatic acute coronary artery occlusion in outpatients with coronary artery disease : a multicentre observational study

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    Background Time delay between onset of symptoms and seeking medical attention is a major determinant of mortality and morbidity in patients with acute coronary artery occlusion. Response time might be reduced by reliable self-detection. We aimed to formally assess the proof-of-concept and accuracy of self-detection of acute coronary artery occlusion by patients during daily life situations and during the very early stages of acute coronary artery occlusion. Methods In this multicentre, observational study, we tested the operational feasibility, specificity, and sensitivity of our RELF method, a three-lead detection system with an automatic algorithm built into a mobile handheld device, for detection of acute coronary artery occlusion. Patients were recruited continuously by physician referrals from three Belgian hospitals until the desired sample size was achieved, had been discharged with planned elective percutaneous coronary intervention, and were able to use a smartphone; they were asked to perform random ambulatory selfrecordings for at least 1 week. A similar self-recording was made before percutaneous coronary intervention and at 60 s of balloon occlusion. Patients were clinically followed up until 1 month after discharge. We quantitatively assessed the operational feasibility with an automated dichotomous quality check of self-recordings. Performance was assessed by analysing the receiver operator characteristics of the ST difference vector magnitude. This trial is registered with ClinicalTrials.gov, number NCT02983396. Findings From Nov 18, 2016, to April 25, 2018, we enrolled 64 patients into the study, of whom 59 (92%) were eligible for self-applications. 58 (91%) of 64 (95% CI 81.0-95.6) patients were able to perform ambulatory self-recordings. Of all 5011 self-recordings, 4567 (91%) were automatically classified as successful within 1 min. In 65 balloon occlusions, 63 index tests at 60 s of occlusion in 55 patients were available. The mean specificity of daily life recordings was 0.96 (0.95-0.97). The mean false positive rate during daily life conditions was 4.19% (95% CI 3.29-5.10). The sensitivity for the target conditions was 0.87 (55 of 63; 95% CI 0.77-0.93) for acute coronary artery occlusion, 0.95 (54 of 57; 0.86-0.98) for acute coronary artery occlusion with electrocardiogram (ECG) changes, and 1.00 (35 of 35) for acute coronary artery occlusion with ECG changes and ST-segment elevation myocardial infarction criteria (STEMI). The index test was more sensitive to detect a 60 s balloon occlusion than the STEMI criteria on 12-lead ECG (87% vs 56%; p<0.0001). The proportion of total variation in study estimates due to heterogeneity between patients (I-2) was low (12.6%). The area under the receiver operator characteristics curve was 0.973 (95% CI 0.956-0.990) for acute coronary artery occlusion at different cutoff values of the magnitude of the ST difference vector. No patients died during the study. Interpretation Self-recording with our RELF device is feasible for most patients with coronary artery disease. The sensitivity and specificity for automatic detection of the earliest phase of acute coronary artery occlusion support the concept of our RELF device for patient empowerment to reduce delay and increase Survival without overloading emergency services. Copyright (C) 2019 The Author(s). Published by Elsevier Ltd

    Dysbiosis of bifidobacteria and Clostridium cluster XIVa in the cystic fibrosis fecal microbiota

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    BACKGROUND: Recurrent antimicrobial interventions and disease-related intestinal dysfunction are suspected to contribute to the dysbiosis of the gastrointestinal microbial ecosystem in patients with cystic fibrosis (CF). The present study set out to detect and identify microbial discriminants in the gut microbiota composition that are associated with CF-related intestinal dysbiosis. METHODS: An in-depth description of CF-associated gut dysbiosis was obtained by screening denaturing gradient gel electrophoresis (DGGE) fingerprints for potentially discriminating bacterial species, and quantification by means of real-time PCR analyses using group-specific primers. RESULTS: A total of 8 DGGE band-classes assigned to the genus Bifidobacterium (n=3), and members of Clostridium clusters XIVa (n=3) and IV (n=2), were significantly (p<0.05) underrepresented in samples of patients with CF. Real-time PCR analyses confirmed a significantly lower abundance and temporal stability of bifidobacteria and Clostridium cluster XIVa in the faecal microbiota of patients with CF. CONCLUSION: This study is the first to report specific microbial determinants of dysbiosis in patients with CF

    Ablation of an idiopathic left ventricular tachycardia originating from the posterior mitral annulus in a toddler

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    Ablation of a mitral annulus (MA)-ventricular tachycardia (VT), a rare form of idiopathic left VT, has not yet been described in patients <2 years of age. We describe a case of a toddler with an incessant, poorly tolerated idiopathic VT (190 bpm) refractory to medical therapy, which was successfully ablated in the left ventricle at the infero-posterior part of the MA. Different diagnostic and ablation steps are described. Mitral annulus-ventricular tachycardia, a rare form of idiopathic left VT, can safely and successfully be ablated in very young children

    First successful radiofrequency ablation of focal atrial tachycardia in a horse guided by a high density 3D electro-anatomical mapping system (Rhythmia®)

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    Transvenous electrical cardioversion (TVEC) has a 95% success rate for cardioversion of atrial tachyarrhythmia but recurrence rate is about 35%. A 5-year-old showjumper stallion with regular atrial tachyarrhythmia was treated successfully with TVEC twice but showed early recurrence each time. An electrophysiological study suggested a right sided atrial tachycardia and the option for ablation was taken. In the standing horse, a decapolar catheter and two TVEC catheters, in case atrial fibrillation would occur during the procedure, were inserted in the left jugular vein and placed in the coronary sinus, right atrium and left pulmonary artery, respectively. Subsequently, under general anesthesia, an electro-anatomical mapping catheter (Intellamap Orion, Boston Scientific) was inserted into the right jugular vein and used to create a 3D electro-anatomical map (Rhythmia, Boston Scientific) of right atrium and venae cavae. Activation mapping, whereby the coronary sinus signal served as time reference, revealed a focal atrial tachycardia with a cycle length of 400ms with earliest activity at the caudodorsal interatrial wall. An ablation catheter (Intellanav OI, Boston Scientific) was guided towards the site of earliest activation using the Rhythmia mapping system and targeted for ablation. During the 5th application (temperature-controlled 60W, maximal temperature 60°C), the atrial tachycardia terminated and became non-inducible. Total ablation time was 366 seconds. Recovery was uneventful. This is the first time that the exact origin of an atrial arrhythmia is identified by 3D electro-anatomical mapping and is successfully treated by radiofrequency ablation. This study proves that both techniques are technically feasible in adult horses

    <i>Photobacterium sanctipauli</i> sp. nov. isolated from bleached <i>Madracis decactis</i> (Scleractinia) in the St Peter & St Paul Archipelago, Mid-Atlantic Ridge, Brazil

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    Five novel strains of Photobacterium (A-394T, A-373, A-379, A-397 and A-398) were isolated from bleached coral Madracis decactis (scleractinian) in the remote St Peter & St Archipelago (SPSPA), Mid-Atlantic Ridge, Brazil. Healthy M. decactis specimens were also surveyed, but no strains were related to them. The novel isolates formed a distinct lineage based on the 16S rRNA, recA, and rpoA gene sequences analysis. Their closest phylogenetic neighbours were Photobacterium rosenbergii, P. gaetbulicola, and P. lutimaris, sharing 96.6 to 95.8% 16S rRNA gene sequence similarity. The novel species can be differentiated from the closest neighbours by several phenotypic and chemotaxonomic markers. It grows at pH 11, produces tryptophane deaminase, presents the fatty acid C18:0, but lacks C16:0 iso. The whole cell protein profile, based in MALDI-TOF MS, distinguished the strains of the novel species among each other and from the closest neighbors. In addition, we are releasing the whole genome sequence of the type strain. The name Photobacterium sanctipauli sp. nov. is proposed for this taxon. The G + C content of the type strain A-394T (= LMG27910T = CAIM1892T) is 48.2 mol%
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