106 research outputs found

    The Impact of Biases in the Crowdsourced Trajectories on the Output of Data Mining Processes

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    The emergence of the Geoweb has provided an unprecedented capacity for generating and sharing digital content by professional and non- professional participants in the form of crowdsourcing projects, such as OpenStreetMap (OSM) or Wikimapia. Despite the success of such projects, the impacts of the inherent biases within the ‘crowd’ and/or the ‘crowdsourced’ data it produces are not well explored. In this paper we examine the impact of biased trajectory data on the output of spatio-temporal data mining process. To do so, an experiment was conducted. The biases are intentionally added to the input data; i.e. the input trajectories were divided into two sets of training and control datasets but not randomly (as opposed to the data mining procedures). They are divided by time of day and week, weather conditions, contributors’ gender and spatial and temporal density of trajectory in 1km grids. The accuracy of the predictive models are then measured (both for training and control data) and biases gradually moderated to see how the accuracy of the very same model is changing with respect to the biased input data. We show that the same data mining technique yields different results in terms of the nature of the clusters and identified attributes

    A rare presentation of late right coronary artery spasm following aortic valve replacement

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    BACKGROUND: Coronary artery spasm (CAS) is defined as a reversible, sudden epicardial coronary artery stenosis that causes vessel occlusion or near occlusion. CASE REPORT: In this article, we present a clinical case of CAS in a 48-year-old woman undergoing elective aortic valve replacement surgery for aortic stenosis. On the 3rd post-operative day, the patient suffered from chest pain and dyspnea. Emergent coronary angiography demonstrated a significant spasm of the ostium portion of the right coronary artery. CONCLUSION: This case shows that delayed coronary spasm should be considered as a cause of hemodynamic instability after valvular surgery. © 2015, Isfahan University of Medical Sciences(IUMS). All rights reserved

    Identifying Urban Functional Areas and Their Dynamic Changes in Beijing: Using Multiyear Transit Smart Card Data

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    A growing number of megacities have been experiencing changes to their landscape due to rapid urbanisation trajectories and travel behaviour dynamics. Therefore, it is of great significance to investigate the distribution and evolution of a city’s urban functional areas over different periods of time. Although the smart card automated fare collection system (SCAFC) is already widely used, few studies have used smart card data to infer information about changes in urban functional areas, particularly in developing countries. Thus, this research aims to delineate the dynamic changes that have occurred in urban functional areas based on passengers’ travel patterns, using Beijing as a case study. We established a Bayesian framework and applied a Gaussian mixture model (GMM) derived from transit smart card data in order to gain insight into passengers’ travel patterns at station level and then identify the dynamic changes in their corresponding urban functional areas. Our results show that Beijing can be clustered into five different functional areas based on the analysis of corresponding transit station functions, namely: multimodal interchange hub and leisure area; residential area; employment area; mixed but mainly residential area; and a mixed residential and employment area. In addition, we found that urban functional areas have experienced slight changes between 2014 and 2017. The findings can be used to inform urban planning strategies designed to tackle urban spatial structure issues, as well as guiding future policy evaluation of urban landscape pattern use

    Human health risk assessment due to ambient PM10 and SO2 by an air quality modeling technique

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    Exposure to air pollutants may be an important environmental risk factor for human health. The main objective of this study was to assess the health impacts of exposure to particulate matter of aerodynamic diameter <= 10 mu g (PM10) and to sulfur dioxide (SO2) using the AirQ2.2.3 software developed by the WHO European Center for Environment and Health. Daily concentrations of PM10 and SO2 were used to assess the health effects. With regard to the mortality, the results showed that 3.9 (95 CI: 3.3-4.5) of total, 4.2 (95 CI: 2.7-9.05) of cardiovascular, and 6.2 (95 CI: 4.2-16.9) of respiratory mortality were related to PM10 concentrations above 10 mu g/m(3), respectively. In addition, 1.7 (95 CI: 1.3-2.06) of total, 3.4 (95 CI: 0.78-5.0) of cardiovascular, and 2 (95 CI: 2.5-5.7) of respiratory death were attributed to SO2 levels higher than 10 mu g/m(3), respectively. Given these findings, urgent policy decisions are needed to reduce the death caused by air pollution, and better quantification studies are recommended. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved

    Slow graft function after pediatric renal transplantation from volunteer live donors

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    Slow graft function (SGF) may occur during the early post-transplant period. In this paper, we present our findings regarding SGF after pediatric renal transplantation and its predictive variables. From 1985 to 2004, a total of 300 pediatric renal transplants were performed at our institution. A total of 10 cases with SGF and 50 controls that were operated by the same surgeons were enrolled in this study. The mean age of the recipients and donors was 11.4 (3-15 yr) and 28.05 yr (20-50 yr), respectively. All kidneys were retrieved from living donors. We compared patients with SGF with controls regarding four independent variables: age difference between donors and recipients, serum hemoglobin difference between donors and recipients, mean blood pressure (systolic blood pressure + 2 diastolic blood pressure/3) difference between donors and recipients, and weight difference between donors and recipients. The mean age of recipients was 10.5 ± 4.1 in SGF group and 11.6 ± 2.5 in control group (p = 0.4). The differences between donors and recipients regarding weight and mean blood pressure in subjects with SGF were not higher than other patients (42 kg vs. 37.4 kg, p = 0.4; -3 mmHg vs. -4.1 mmHg, p = 0.8). The mean hemoglobin difference between donors and recipients was 6.3 ± 2.1 g/dL in SGF group and 6.7 ± 2.3 g/dL in control group (p = 0.6). The differences between donors and recipients regarding age, weight, mean blood pressure and serum hemoglobin level are not predictive variables for SGF. © 2007 Blackwell Munksgaard

    Making tourist guidance systems more intelligent, adaptive and personalised using crowd sourced movement data

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    Ambient intelligence (AmI) provides adaptive, personalized, intelligent, ubiquitous and interactive services to wide range of users. AmI can have a variety of applications, including smart shops, health care, smart home, assisted living, and location-based services. Tourist guidance is one of the applications where AmI can have a great contribution to the quality of the service, as the tourists, who may not be very familiar with the visiting site, need a location-aware, ubiquitous, personalised and informative service. Such services should be able to understand the preferences of the users without requiring the users to specify them, predict their interests, and provide relevant and tailored services in the most appropriate way, including audio, visual, and haptic. This paper shows the use of crowd sourced trajectory data in the detection of points of interests and providing ambient tourist guidance based on the patterns recognised over such data

    Methods to Study Centrosomes and Cilia in Drosophila

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    The deposited item is a book chapter and is part of the series " Methods in Molecular Biology book series ([MIMB, volume 1454]) published by the publisher Humana Press.The deposited book chapter is a pre-print version and hasn't been submitted to peer reviewing.There is no public supplementary material available for this publication.This publication hasn't any creative commons license associated.Centrioles and cilia are highly conserved eukaryotic organelles. Drosophila melanogaster is a powerful genetic and cell biology model organism, extensively used to discover underlying mechanisms of centrosome and cilia biogenesis and function. Defects in centrosomes and cilia reduce fertility and affect different sensory functions, such as proprioception, olfaction, and hearing. The fly possesses a large diversity of ciliary structures and assembly modes, such as motile, immotile, and intraflagellar transport (IFT)-independent or IFT-dependent assembly. Moreover, all the diverse ciliated cells harbor centrioles at the base of the cilia, called basal bodies, making the fly an attractive model to better understand the biology of this organelle. This chapter describes protocols to visualize centrosomes and cilia by fluorescence and electron microscopy.Fundação Portuguesa para a Ciência e Tecnologia grants: (SFRH/BPD/87479/2012, SFRH/BD/52176/2013); EMBO installation grant; ERC starting grant.info:eu-repo/semantics/publishedVersio

    Can prodromal symptoms predict recurrence of vasovagal syncope?

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    Background: Vasovagal syncope (VVS) is a common symptom with empirical therapy and high recurrence rate. Our goal was to determine whether the pattern of presyncopal prodromal symptoms can predict the recurrence probability of vasovagal syncope. Methods: Seventy-nine consecutive patients (male/female: 53/26) with history of VVS and positive tilt table test (TTT) were enrolled in the study and completed the follow-up time for one year. They all had normal electrocardiograms and cardiac echocardiography without underlying disease. All of them were evaluated meticulously for prodromal symptoms (diaphoresis, nausea, palpitation and blurred vision) and frequency of syncopal spells in their past medical history. They received metoprolol at maximum tolerated dose and were taught tilt training as an empirical therapy after TTT. Results: Fifty-four patients (68.4) reported at least one of the four main prodromal symptoms. Median syncopal ± presyncopal spells were 4 episodes. Forty-two patients (53.2) experienced recurrence of syncope or presyncope during the follow-up period. In recurrent symptomatic patients, diaphoresis had been more significantly reported in their past medical history (p = 0.018) and they had more syncopal spells before TTT (p = 0.001). Age, gender and type of TTT response did not have any effect on the recurrence of VVS. Conclusions: Patients with a history of diaphoresis as a prodromal symptom and more pre-tilt syncopal attacks experience more syncopal or presyncopal spells during follow-up. Copyright © 2008 Via Medica

    The Urological Association of Asia clinical guideline for urinary stone disease

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    The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline – consisting 43 clinical questions – and overview its key practical issues

    An ancestral 10-bp repeat expansion in VWA1 causes recessive hereditary motor neuropathy

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    The extracellular matrix comprises a network of macromolecules such as collagens, proteoglycans and glycoproteins. VWA1 (von Willebrand factor A domain containing 1) encodes a component of the extracellular matrix that interacts with perlecan/collagen VI, appears to be involved in stabilizing extracellular matrix structures, and demonstrates high expression levels in tibial nerve. Vwa1-deficient mice manifest with abnormal peripheral nerve structure/function; however, VWA1 variants have not previously been associated with human disease. By interrogating the genome sequences of 74 180 individuals from the 100K Genomes Project in combination with international gene-matching efforts and targeted sequencing, we identified 17 individuals from 15 families with an autosomal-recessive, non-length dependent, hereditary motor neuropathy and rare biallelic variants in VWA1. A single disease-associated allele p.(G25Rfs*74), a 10-bp repeat expansion, was observed in 14/15 families and was homozygous in 10/15. Given an allele frequency in European populations approaching 1/1000, the seven unrelated homozygote individuals ascertained from the 100K Genomes Project represents a substantial enrichment above expected. Haplotype analysis identified a shared 220 kb region suggesting that this founder mutation arose >7000 years ago. A wide age-range of patients (6–83 years) helped delineate the clinical phenotype over time. The commonest disease presentation in the cohort was an early-onset (mean 2.0 ± 1.4 years) non-length-dependent axonal hereditary motor neuropathy, confirmed on electrophysiology, which will have to be differentiated from other predominantly or pure motor neuropathies and neuronopathies. Because of slow disease progression, ambulation was largely preserved. Neurophysiology, muscle histopathology, and muscle MRI findings typically revealed clear neurogenic changes with single isolated cases displaying additional myopathic process. We speculate that a few findings of myopathic changes might be secondary to chronic denervation rather than indicating an additional myopathic disease process. Duplex reverse transcription polymerase chain reaction and immunoblotting using patient fibroblasts revealed that the founder allele results in partial nonsense mediated decay and an absence of detectable protein. CRISPR and morpholino vwa1 modelling in zebrafish demonstrated reductions in motor neuron axonal growth, synaptic formation in the skeletal muscles and locomotive behaviour. In summary, we estimate that biallelic variants in VWA1 may be responsible for up to 1% of unexplained hereditary motor neuropathy cases in Europeans. The detailed clinical characterization provided here will facilitate targeted testing on suitable patient cohorts. This novel disease gene may have previously evaded detection because of high GC content, consequential low coverage and computational difficulties associated with robustly detecting repeat-expansions. Reviewing previously unsolved exomes using lower QC filters may generate further diagnoses
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