243 research outputs found
Modifying the Symbolic Aggregate Approximation Method to Capture Segment Trend Information
The Symbolic Aggregate approXimation (SAX) is a very popular symbolic
dimensionality reduction technique of time series data, as it has several
advantages over other dimensionality reduction techniques. One of its major
advantages is its efficiency, as it uses precomputed distances. The other main
advantage is that in SAX the distance measure defined on the reduced space
lower bounds the distance measure defined on the original space. This enables
SAX to return exact results in query-by-content tasks. Yet SAX has an inherent
drawback, which is its inability to capture segment trend information. Several
researchers have attempted to enhance SAX by proposing modifications to include
trend information. However, this comes at the expense of giving up on one or
more of the advantages of SAX. In this paper we investigate three modifications
of SAX to add trend capturing ability to it. These modifications retain the
same features of SAX in terms of simplicity, efficiency, as well as the exact
results it returns. They are simple procedures based on a different
segmentation of the time series than that used in classic-SAX. We test the
performance of these three modifications on 45 time series datasets of
different sizes, dimensions, and nature, on a classification task and we
compare it to that of classic-SAX. The results we obtained show that one of
these modifications manages to outperform classic-SAX and that another one
slightly gives better results than classic-SAX.Comment: International Conference on Modeling Decisions for Artificial
Intelligence - MDAI 2020: Modeling Decisions for Artificial Intelligence pp
230-23
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An Overview of the Use of Neural Networks for Data Mining Tasks
In the recent years the area of data mining has experienced a considerable demand for technologies that extract knowledge from large and complex data sources. There is a substantial commercial interest as well as research investigations in the area that aim to develop new and improved approaches for extracting information, relationships, and patterns from datasets. Artificial Neural Networks (NN) are popular biologically inspired intelligent methodologies, whose classification, prediction and pattern recognition capabilities have been utilised successfully in many areas, including science, engineering, medicine, business, banking, telecommunication, and many other fields. This paper highlights from a data mining perspective the implementation of NN, using supervised and unsupervised learning, for pattern recognition, classification, prediction and cluster analysis, and focuses the discussion on their usage in bioinformatics and financial data analysis tasks
The effect of botulinum toxin A in children with non-neurogenic therapy-refractory dysfunctional voiding – A systematic review
Introduction:Dysfunctional voiding (DV) is a habitual voiding disorder caused by involuntary contraction or non-relaxation of the external urethral sphincter (EUS) during voiding. This contraction causes high post-void residuals (PVR), urinary incontinence and urinary tract infections (UTIs). Various treatments for DV are available, but some children do not respond. Intersphincteric botulinum toxin-A (BTX-A) may be a possible treatment for therapy-refractory children with DV.Objective: The aim of this systematic review is to summarize the effects and safety of intersphincteric BTX-A as a treatment for therapy-refractory DV in children. Methods: A systematic search in Embase, MEDLINE, Cochrane, and Web of Science databases was performed. Studies reporting on the usage of intersphincteric BTX-A as a treatment for DV in children were included. Data on PVR, maximum flow rate (Qmax), repeat injections and complications were extracted. Results: From a total of 277 articles, five cohort studies were identified, reporting on 78 children with DV of whom 53 were female (68 %) and 25 were male (32 %). Sample sizes ranged from ten to twenty patients. Mean or median age at the time of intervention ranged from 8 to 10.5 years. Meta-analysis could not be performed due to lack of data. The narrative synthesis approach was therefore used to summarize the results. All studies showed significant decrease in PVR after BTX-A injection. Three studies showed a 33–69 % improvement on incontinence after BTX-A injection. Less UTIs were reported after treatment. A temporary increase in incontinence, UTIs and transitory numbness to the gluteus muscle were reported as side-effects. Conclusions: BTX-A could be a safe and effective treatment option for therapy-refractory DV in children by reducing PVR, UTIs and incontinence. Hereby, the synergistic effect of BTX-A and urotherapy should be emphasized in future management. Furthermore, this study identified gaps in current knowledge that are of interest for future research.</p
The role of epigenetic modifications in cardiovascular disease
_Background:_ Epigenetic modifications of the genome, such as DNA methylation and histone modifications, have been reported to play a role in processes underlying cardiovascular disease (CVD), including atherosclerosis, inflammation, hypertension and diabetes.
_Methods:_ Eleven databases were searched for studies investigating the association between epigenetic marks (either global, site-specific or genome-wide methylation of DNA and histone modifications) and CVD.
_Results:_ Of the 3459 searched references, 31 studies met our inclusion criteria (26 cross-sectional studies and 5 prospective studies). Overall, 12,648 individuals were included, with total of 4037 CVD events. The global DNA methylation assessed at long-interspersed nuclear element (LINE-1) was inversely associated with CVD, independent of established cardiovascular risk factors. Conversely, a higher degree of global DNA methylation measured at Alu repeats or by the LUMA method was associated with the presence of CVD. The studies reported epigenetic regulation of 34 metabolic genes (involved in fetal growth, glucose and lipid metabolism, inflammation, atherosclerosis and oxidative stress) in blood cells to be related with CVD. Among them, 5 loci were validated and methylation at F2RL3 was reported in two large prospective studies to predict cardiovascular disease beyond the traditional risk factors.
_Conclusions:_ Current evidence supports an association between genomic DNA methylation and CVD. However, this review highlights important gaps in the existing evidences including lack of large-scale epigenetic investigation
Pre-procedural image-guided versus non-image-guided ventricular tachycardia ablation—a review
Background Magnetic resonance imaging and computed tomography in patients with ventricular tachycardia (VT) after myocardial infarction (MI) helps to
delineate scar from healthy tissue. Image-guided VT
ablation has not yet been studied on a large scale.
Objective The aim of the meta-analysis was to compare the long-term outcome of image-guided VT ablation with a conventional approach for VT after MI.
Methods Eight electronic bibliographic databases
were searched to identify all relevant studies from
2012 until 2018. The search for scientific literature
was performed for studies that described the outcome of VT ablation in patients with an ischaemic
substrate. The outcome o
Fetal sex and maternal pregnancy outcomes: a systematic review and meta-analysis
BACKGROUND: Since the placenta also has a sex, fetal sex-specific differences in the occurrence of placenta-mediated complications could exist. OBJECTIVE: To determine the association of fetal sex with multiple maternal pregnancy complications. SEARCH STRATEGY: Six electronic databases Ovid MEDLINE, EMBASE, Cochrane Central, Web-of-Science, PubMed, and Google Scholar were systematically searched to identify eligible studies. Reference lists of the included studies and contact with experts were also used for identification of studies. SELECTION CRITERIA: Observational studies that assessed fetal sex and the presence of maternal pregnancy complications within singleton pregnancies. DATA COLLECTION AND ANALYSES: Data were extracted by 2 independent reviewers using a predesigned data collection form. MAIN RESULTS: From 6522 original references, 74 studies were selected, including over 12,5 million women. Male fetal sex was associated with term pre-eclampsia (pooled OR 1.07 [95%CI 1.06 to 1.09]) and gestational diabetes (pooled OR 1.04 [1.02 to 1.07]). All other pregnancy complications (i.e., gestational hypertension, total pre-eclampsia, eclampsia, placental abruption, and post-partum hemorrhage) tended to be associated with male fetal sex, except for preterm pre-eclampsia, which was more associated with female fetal sex. Overall quality of the included studies was good. Between-study heterogeneity was high due to differences in study population and outcome definition. CONCLUSION: This meta-analysis suggests that the occurrence of pregnancy complications differ according to fetal sex with a higher cardiovascular an
Exploring Territorial Imbalances: A Systematic Literature Review of Meanings and Terms
Within the framework of the EU Strategies of Territorial Cohesion, a relevant role is played by policy design focused on a more balanced and equal development of regions pursued by regenerating and improving endogenous resources. A place-sensitive instead of place-neutral approach can be useful to overcome weaknesses, innovation gaps and social-economic issues related to asymmetric and unequal development between and within regions. This paper deals with the complexity of territorial imbalances and spatial inequalities by focusing on lacking, declining and marginal areas. By developing a Systematic Literature Review, a first mapping of terms, practices and issues related to those areas has been developed in order to investigate scenarios in different geo-political contexts and at various spatial scales. The Systematic Literature Review approach has permitted the systematization of a multitude of terms referring to gaps between core areas and areas suffering from territorial imbalances, as well as the exploration of disciplinary sectors, geographical contexts, document typologies, frequency of terms, and to develop a preliminary geo-localization of practices. The findings of this first step are relevant to providing a systematic knowledge base within a complex field in which a clarification of meanings, scales and processes is needed
Symptomatic, biochemical and radiographic recovery in patients with Covid-19
Background: The symptoms, radiography, biochemistry and healthcare utilisation of patients with COVID-19 following discharge from hospital have not been well described. Methods: Retrospective analysis of 401 adult patients attending a clinic following an index hospital admission or emergency department attendance with COVID-19. Regression models were used to assess the association between characteristics and persistent abnormal chest radiographs or breathlessness. Results: 75.1% of patients were symptomatic at a median of 53 days post discharge and 72 days after symptom onset and chest radiographs were abnormal in 47.4%. Symptoms and radiographic abnormalities were similar in PCR-positive and PCR-negative patients. Severity of COVID-19 was significantly associated with persistent radiographic abnormalities and breathlessness. 18.5% of patients had unscheduled healthcare visits in the 30 days post discharge. Conclusions: Patients with COVID-19 experience persistent symptoms and abnormal blood biomarkers with a gradual resolution of radiological abnormalities over time. These findings can inform patients and clinicians about expected recovery times and plan services for follow-up of patients with COVID-19
Rapid literature review on the impact of health messaging and product information on alcohol labelling
Background and aim Alcohol labelling enables people to make informed decisions about the products they purchase and consume. This rapid review explores the impact of health messaging and product information on consumer attention, comprehension, recall, judgment and behavioural compliance in relation to alcohol use. Methods The rapid review adopted a multi-faceted search strategy to identify primary studies on health messaging and/or product information on alcohol packaging, and the impact of these on consumer-related outcomes. Results The review provides support for large, colourful labels on the front of alcohol products and the use of plain packaging to increase the visibility of health messaging. It also supports the use of explicit, negatively-framed statements that link alcohol to specific diseases. Colour-coded schemes and pictorial warnings may further optimize the effectiveness of alcohol labels. We did not find sufficient evidence to support the effectiveness of product information alone in influencing consumerattention, comprehension, recall, judgment and behavioural compliance. Conclusion Well-designed alcohol labels can positively influence consumers’ attention, comprehension, recall, judgment and behavioural compliance. The findings have implications for alcohol labelling research and policy.Output Status: Forthcoming/Available Onlin
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