501 research outputs found

    Mullite coatings on ceramic substrates: Stabilisation of Al2O3-SiO2 suspensions for spray drying of composite granules suitable for reactive plasma spraying

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    The present work deals with the preparation of stable alumina + silica suspensions with high solid loading for the production of spray-dried composite powders. These composite powders are to be used for reactive plasma spraying whereby the formation of mullite and the coating on a ceramic substrate are achieved in a single step process. Electrostatic stabilisation of alumina and silica suspensions has been studied as a function of pH. Silica suspensions are most stable at basic pH whereas alumina suspensions are stable at acidic pH. The addition of ammonium polymethacrylate (APMA) makes it possible to stabilise alumina and prepare a stable 50 wt% alumina + silica suspension at pH 10. The optimum amounts of dispersant and binder have been determined by zeta potential, viscosity and sedimentation measurements. Spray drying of the suspension yields composite powders whose morphology, size distribution and flowability have been characterized before realizing reactive plasma spraying tests. (C) 2009 Elsevier Ltd. All fights reserved

    A Neolithic occupation at the bottom of the Monts de Vaucluse, the site of La Boudine in Saumane-de-Vaucluse

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    Le site de La Boudine est localisĂ© sur la commune de Saumane-de-Vaucluse. Le mobilier archĂ©ologique dĂ©couvert ensurface a pu ĂȘtre attribuĂ© au NĂ©olithique moyen. Cette homogĂ©nĂ©itĂ© et la proximitĂ© du site avec les gisements de silex bĂ©doulien des monts de Vaucluse, ont motivĂ© une opĂ©ration de sondage. Des lambeaux d’occupation nĂ©olithique ont pu ĂȘtre dĂ©couverts. Le site a Ă©tĂ© fortement Ă©rodĂ© mais cette opĂ©ration permet de documenter positivement l’occupation humaine dans les piĂ©monts des monts de Vaucluse.The site of La Boudine is located on the municipality of Saumane-de-Vaucluse. The artefacts on surface can be attributed to middle Neolithic. This homogeneity and the proximity with the deposits of bedoulian flint of Monts de Vaucluse, have motivated an excavation. Remaining of Neolithic activity have been discovered. The site was strongly affected by erosion. However, this studies allows to document the human activity in piedmont of monts de Vaucluse

    FEELnc : a tool for long non-coding RNA annotation and its application to the dog transcriptome

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    Whole transcriptome sequencing (RNA-seq) has become a standard for cataloguing and monitoring RNA populations. One of the main bottlenecks, however, is to correctly identify the different classes of RNAs among the plethora of reconstructed transcripts, particularly those that will be translated (mRNAs) from the class of long non-coding RNAs (lncRNAs). Here, we present FEELnc (FlExible Extraction of LncRNAs), an alignment-free program that accurately annotates lncRNAs based on a Random Forest model trained with general features such as multi k-mer frequencies and relaxed open reading frames. Benchmarking versus five state-of-the-art tools shows that FEELnc achieves similar or better classification performance on GENCODE and NONCODE data sets. The program also provides specific modules that enable the user to fine-tune classification accuracy, to formalize the annotation of lncRNA classes and to identify lncRNAs even in the absence of a training set of non-coding RNAs. We used FEELnc on a real data set comprising 20 canine RNA-seq samples produced by the European LUPA consortium to substantially expand the canine genome annotation to include 10 374 novel lncRNAs and 58 640 mRNA transcripts. FEELnc moves beyond conventional coding potential classifiers by providing a standardized and complete solution for annotating lncRNAs and is freely available at https://github.com/tderrien/FEELnc.Peer reviewe

    Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

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    Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Influence of two sports vision training techniques on visual skills performance of university students

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    Vision is an essential sense and crucial throughout a student’s academic career. Reading and writing during formal studies require a basic level of visual skills. Training of visual skills to students may improve the way visual stimuli are processed, and subsequently lead to visual skill-, motor- and cognitive performance enhancement. The visual system processes information by way of ‘hardware’- skills (physical, mechanical properties) and the more trainable ‘software’-skills (perceptual, cognitive abilities). Sports vision skills training in athletes indicated faster response to visual information and ultimately improved performance, particularly in fast-ball sports. The efficiency of two sports vision training programmes were tested and compared in undergraduate physiology students of various ethnicities (aged 18-25 years), during a 6-week training period. Three groups were used. One control group and two experimental groups were used. Two programmes were used for the experimental groups (a vision laboratory executed battery of repeated visual skills vs. ‘Eyedrills’ an available webbased training programme). Both comprised ‘hardware’ and ‘software’ skills, and include: visual acuity, focusing, tracking, vergence, sequencing, eye-hand coordination and visualisation. For pretest/ post-test evaluations of all students the repeated laboratory training programme was executed. The control group was only exposed to the pre- and post-test. Individuals trained in the laboratory indicated the highest improvement in all visual skills, except vergence. The ‘Eyedrills’ group displayed significant improvements in focusing, tracking and eye-hand coordination, with the control group indicating the least improvement in visual skills - ruling out the notion of improvement occurring only due to test familiarity. Visual training was verified an essential method of improving visual skills, and fundamental in the expansion of basic visual abilities of university students for enhanced performance.http://www.journals.co.za/content/journal/ajpherd1am2017Biokinetics, Sport and Leisure SciencesPhysiologyPsychologySports MedicineStatistic
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