222 research outputs found

    Identification of acoustic emission sources in machinery; application to injection/combustion processes in diesel engines

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    The high temporal resolution of Acoustic Emission offers great promise in the on-line monitoring of complex machines such as diesel engines. The fuel injection process is one of the most important processes in the diesel engine and its timing and fuel delivery control are critical in combustion efficiency. In this work, the phenomena leading to the generation of acoustic emission during injection are investigated by simulation of the injection process in a specially designed rig and through test in running engines on a test-bed. Signal processing approaches are devised to produce diagnostic indicators for the quality of the injection process. The novelty of the research lies in; 1) obtaining a coherent set of data which allows the separation of the part of the signal associated with injection in a given cylinder from other sources adjacent in time and space, and 2) in developing a signal processing approach which allows this separation to be achieved on line using an array of sensors. As such, the research is generic to multi-source multi-sensor analysis in machines. A series of experiments were performed on an experimental injector rig, and two-stroke and four-stroke diesel engines under different operating conditions. The injector rig experiments provided useful information on the characteristic signatures of the injection events, finding which could be implemented to the more complex signal from the running engines. A number of sensor arrays (sets of two and three sensors) were used on two types of four-stroke engine at different running speeds to investigate the source identification of the injection events, the essential strategy being to add complexity to the information in the AE record by using engines of varying degrees of mechanical sophistication. It has been concluded that the AE signals are generated by the mechanical movements of the components in the pump and injector as well as aspects of the fuel flow through the injector and the piping. Also, it is found that the temporal structure of the AE is highly sensitive to sensor position, and that transmission path differences to a sensor array are generally large enough to allow source separation. Applying a purpose-designed thresholding technique, followed by canonical correlation allows the separate identification of parts of the AE signal in the short crank angle widow where sources involved in injection, inlet valve opening and combustion are operating

    L’emploi de la caricature dans le dĂ©veloppement des habiletĂ©s de la lecture critique des apprenants de français langue Ă©trangĂšre et leurs perceptions

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    La lecture joue un grand rĂŽle dans le processus d’enseignement-apprentissage. Elle constitue une base solide de la formation didactique de l’apprenant pour s’adapter Ă  la sociĂ©tĂ©. Il existe quatre niveaux de comprĂ©hension en lecture : littĂ©rale, infĂ©rentielle ou interprĂ©tative, critique et crĂ©ative. Les habiletĂ©s de ces quatre niveaux de comprĂ©hension sont organisĂ©es selon la hiĂ©rarchie de la taxonomie de Bloom. Notre recherche portait sur le niveau de la comprĂ©hension critique en lecture : la lecture critique. À la suite d’une recension de la littĂ©rature scientifique, nous avons constatĂ© que les recherches connues Ă  ce jour appuient l’importance de s’intĂ©resser Ă  la didactique de la lecture en classe de français. Cependant, les rĂ©sultats semblent peu concluants Ă  l’égard de la lecture critique, malgrĂ© son importance. La problĂ©matique de notre recherche consiste au fait que les apprenants du Français Langue ÉtrangĂšre (FLE) Ă©prouvent des difficultĂ©s en lecture critique. Ils tendent vers une comprĂ©hension globale du texte sans chercher ni comprendre le sens implicite. D’une part, diffĂ©rents auteurs ont montrĂ© que les raisons de ces difficultĂ©s ne sont pas dues seulement aux Ă©tudiants eux-mĂȘmes mais aussi aux mĂ©thodes d'enseignement non appropriĂ©es Ă  enseigner la lecture critique en FLE. Dans le domaine de l'enseignement des langues Ă©trangĂšres aux locuteurs d'autres langues, certains auteurs prĂ©conisent Ă©galement la didactique de la lecture critique oĂč les enseignants ne font pas juste enseigner aux Ă©tudiants les compĂ©tences linguistiques de base ou de former leurs habiletĂ©s de communication, mais aussi le besoin de dĂ©velopper la conscience critique chez les apprenants qui leur permettent de poser des questions plutĂŽt que d'accepter passivement l'information qu'ils trouvent. D’autre part, la recension a montrĂ© que l’enseignement basĂ© sur la caricature semble motivant et amĂšne les apprenants Ă  rĂ©flĂ©chir, mais que ce support didactique n’a pas Ă©tĂ© utilisĂ© auprĂšs d’apprenants de français, surtout au niveau universitaire. Des Ă©tudes ont prouvĂ© l’efficacitĂ© de la caricature dans l’enseignement de l’histoire, les sciences et la littĂ©ratie visuelle et politique. Aucune Ă©tude, d’aprĂšs notre recension d’écrits, n’a portĂ© sur la caricature en didactique de FLE. D’ailleurs c’est un domaine peu investiguĂ©. Notre recherche exploratoire voulait intĂ©grer la caricature dans l'enseignement de la lecture critique en FLE. En dĂ©finitive, notre recherche visait Ă  rĂ©pondre Ă  la question gĂ©nĂ©rale suivante : Quelle est la contribution de la caricature comme support didactique au dĂ©veloppement des habiletĂ©s de la lecture critique chez les apprenants du FLE ? De cette question dĂ©coulent les questions spĂ©cifiques suivantes : 1- Quel est le rĂŽle de la caricature comme support didactique dans le dĂ©veloppement de la lecture critique chez les apprenants du FLE ? Et 2- quelles sont les perceptions des apprenants ciblĂ©s Ă  l’égard de la caricature ? Pour ce faire, notre recherche a impliquĂ© l’élaboration d’un dispositif didactique au cƓur duquel figurait la caricature. Afin de recueillir les donnĂ©es, nous avons choisi un Ă©chantillon volontaire parmi des Ă©tudiants adultes qui apprennent le FLE, Ă  l’UniversitĂ© de Sherbrooke. Notre expĂ©rimentation didactique consistait Ă  leur faire vivre des activitĂ©s de lecture critique de textes basĂ©s sur la caricature en trois sĂ©ances complĂ©mentaires. Les outils de collecte de donnĂ©es Ă©taient les suivants : des prĂ©tests qui prĂ©cĂ©daient chaque sĂ©ance du dispositif didactique pour diagnostiquer le niveau des Ă©tudiants en lecture critique, des posttests en lecture critique qui suivaient chacune des sĂ©ances, des entrevues pour identifier les perceptions et les productions des participants. Nous avons analysĂ© l'ensemble des donnĂ©es. Il s’agissait d’une analyse Ă©valuative des rĂ©ponses des participants dans les prĂ©/posttests; d’une analyse thĂ©matique du verbatim des entrevues afin d’identifier les perceptions des participants ; et d’une analyse du contenu des caricatures produites par les participants pour appuyer les rĂ©sultats obtenus. Les rĂ©sultats de l’analyse ont indiquĂ© que la caricature a contribuĂ© au dĂ©veloppement de la lecture critique chez les apprenants du FLE : grandement chez les dĂ©butants et les intermĂ©diaires et partiellement chez les avancĂ©s. En parallĂšle, la caricature Ă©tait positivement perçue par tous les participants. Ceux-ci ont avancĂ© que la caricature Ă©tait pour eux une expĂ©rience originale, motivante et transfĂ©rable. Ces rĂ©sultats combinĂ©s avec ceux des recherches antĂ©rieures dans le mĂȘme domaine laissent entrevoir que la caricature comme support didactique pourrait favoriser la comprĂ©hension en lecture en gĂ©nĂ©ral chez les apprenants adultes.  Abstract: Reading plays an important role in the teaching / learning process. It constitutes a solid basis for the didactic training of the learner to adapt to society. There are four levels of reading comprehension: literal, inferential or interpretive, critical and creative. The skills of these four levels of understanding are organized according to the hierarchy of Bloom's taxonomy. Our research focused on the level of critical reading comprehension: critical reading. Following a review of the scientific literature, we found that the research known to date supports the importance of taking an interest in reading literacy in French. However, the results seem inconclusive with regard to critical reading, despite its importance. The problem of our research is that the learners of the French Foreign Language (FFL) have difficulties in critical reading. They tend towards a global understanding of the text without going further in the implicit sense. On the one hand, different authors have shown that the reasons for these difficulties are not only due to the students themselves but also to the teaching methods not appropriate to teach critical reading in FFL. In the field of foreign language teaching to speakers of other languages, some authors also advocate the teaching of critical reading where teachers do not just teach students basic language skills or train their communication skills, but also the need to develop critical awareness in learners that allow them to ask questions rather than passively accepting the information they find. On the other hand, the review showed that teaching based on caricature seems motivating and leads learners to think, but that this didactic support was not used with learners of French, especially at the university level. Studies have proven the effectiveness of caricature in the teaching of history, science and visual and political literacy. No study, according to our review of writings, has focused on the caricature in didactics of FFL. Besides, it is a little investigated field. Our exploratory research wanted to integrate caricature into the teaching of critical reading in FFL. As a conclusion, our research aimed to answer the following general question: What is the contribution of caricature as a didactic medium to the development of the skills of critical reading in the learners of the FFL? From this issue arise the following specific questions: 1- What is the role of caricature as a didactic medium in the development of critical reading in the learners of the FFL? And what are the perceptions of targeted learners about caricature? To do this, our research involved the development of a didactic system at the heart of which caricature was included. In order to collect the data, we chose a sample of adult learners who were studying at the University of Sherbrooke. Our didactic experimentation consisted in making them live the activities of critical reading of texts based on caricature in three complementary stages. The data collection tools included pre-tests that preceded each stage of the didactic experimentation to diagnose the participant’s level in critical reading; post-tests that followed each stage; interviews to identify their perceptions, and drawings produced by them. We analyzed all the data. This was an evaluative analysis of the students' responses in pre / posttests; a thematic analysis of the interview verbatim in order to identify their perceptions; and an analysis of the content of the caricatures produced in support of the results obtained. The results of the analysis showed that caricature has greatly contributed to the development of critical reading in FFL among the beginners and intermediates and partially among the advanced students. At the same time, the caricature was positively perceived by all participants. These ones argued that caricature was an original, motivating and transferable experience. These results, combined with previous research in the same field, suggest that caricature as a didactic medium could promote reading comprehension in adult learners in general

    Allogeneic Hematopoietic Cell Transplantation Improves Outcome in Myelodysplastic Syndrome Across High-Risk Genetic Subgroups:Genetic Analysis of the Blood and Marrow Transplant Clinical Trials Network 1102 Study

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    PURPOSE:Allogeneic hematopoietic cell transplantation (HCT) in patients with myelodysplastic syndrome (MDS) improves overall survival (OS). We evaluated the impact of MDS genetics on the benefit of HCT in a biological assignment (donor v no donor) study.METHODS:We performed targeted sequencing in 309 patients age 50-75 years with International Prognostic Scoring System (IPSS) intermediate-2 or high-risk MDS, enrolled in the Blood and Marrow Transplant Clinical Trials Network 1102 study and assessed the association of gene mutations with OS. Patients with TP53 mutations were classified as TP53multihit if two alleles were altered (via point mutation, deletion, or copy-neutral loss of heterozygosity).RESULTS:The distribution of gene mutations was similar in the donor and no donor arms, with TP53 (28% v 29%; P =.89), ASXL1 (23% v 29%; P =.37), and SRSF2 (16% v 16%; P =.99) being most common. OS in patients with a TP53 mutation was worse compared with patients without TP53 mutation (21% ± 5% [SE] v 52% ± 4% at 3 years; P &lt;.001). Among those with a TP53 mutation, OS was similar between TP53single versus TP53multihit (22% ± 8% v 20% ± 6% at 3 years; P =.31). Considering HCT as a time-dependent covariate, patients with a TP53 mutation who underwent HCT had improved OS compared with non-HCT treatment (OS at 3 years: 23% ± 7% v 11% ± 7%; P =.04), associated with a hazard ratio of 3.89; 95% CI, 1.87 to 8.12; P &lt;.001 after adjustment for covariates. OS among patients with molecular IPSS (IPSS-M) very high risk without a TP53 mutation was significantly improved if they had a donor (68% ± 10% v 0% ± 12% at 3 years; P =.001).CONCLUSION:HCT improved OS compared with non-HCT treatment in patients with TP53 mutations irrespective of TP53 allelic status. Patients with IPSS-M very high risk without a TP53 mutation had favorable outcomes when a donor was available.</p

    Comparing Outcomes with Bone Marrow or Peripheral Blood Stem Cells as Graft Source for Matched Sibling Transplants in Severe Aplastic Anemia across Different Economic Regions

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    Bone marrow (BM) is the preferred graft source for hematopoietic stem cell transplantation (HSCT) in severe aplastic anemia (SAA) compared to mobilized peripheral blood stem cells (PBSC). We hypothesized that this recommendation may not apply to those regions where patients present later in their disease course, with heavier transfusion load and with higher graft failure rates. Patients with SAA who received HSCT from an HLA-matched sibling donor from 1995 to 2009 and reported to the Center for International Blood and Marrow Transplant Research or the Japan Society for Hematopoietic Cell Transplantation were analyzed. The study population was categorized by gross national income per capita (GNI) and region/countries into four groups. Groups analyzed were high income countries (HIC), which were further divided into US-Canada (N=486) and other HIC (N=1264), upper middle-income (UMIC) (N=482), and combined lower middle, low income countries (LM-LIC) (N=142). In multivariate analysis, overall survival (OS) was highest with BM as graft source in HIC compared to PBSC in all countries or BM in UMIC or LM-LIC (p<0.001). There was no significant difference in OS between BM and PBSC in UMIC (p=0.32) or LM-LIC (p=0.23). In LM-LIC the 28-day neutrophil engraftment was higher with PBSC compared to BM (97% vs. 77%, p<0.001). Chronic GVHD was significantly higher with PBSC in all groups. Whereas BM should definitely be the preferred graft source for HLA-matched sibling HSCT in SAA, PBSC may be an acceptable alternative in countries with limited resources when treating patients at high risk of graft failure and infective complications

    Prophylactic, preemptive, and curative treatment for sinusoidal obstruction syndrome/veno-occlusive disease in adult patients : a position statement from an international expert group

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    Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life-threatening complication that can develop after hematopoietic cell transplantation (HCT). While SOS/VOD may resolve within a few weeks in the majority of patients with mild-to-moderate disease, the most severe forms result in multiorgan dysfunction and are associated with a high mortality rate (>80%). Therefore, careful surveillance may allow early detection of SOS/VOD, particularly as the licensed available drug is proven to be effective and reduce mortality. The aim of this work is to propose an international consensus guideline for the treatment and prevention of SOS/VOD in adult patients, on behalf of an international expert group.Peer reviewe

    In-hospital mortality in SARS-CoV-2 stratified by hemoglobin levels : a retrospective study

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    This study is to estimate in-hospital mortality in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients stratified by hemoglobin (Hb) level. Patients were stratified according to hemoglobin level into two groups, that is, Hb 100 g/L. A total of 6931 patients were included. Of these, 6377 (92%) patients had hemoglobin levels >100 g/L. The mean age was 44 ± 17 years, and 66% of the patients were males. The median length of overall hospital stay was 13 days [2; 31]. The remaining 554 (8%) patients had a hemoglobin level 100 g/L (52, 0.82%). Risk factors associated with increased mortality were determined by multi- variate analysis. The Kaplan-Meier survival analysis showed hemoglobin as a predictor of mortality. Cox proportional hazards regression coefficients for hemoglobin for the HB ≀ 100 category of hemoglobin were significant, B = 2.79, SE = 0.17, and HR = 16.34, p < 0.001. Multivariate logistic regression showed Hb < 100 g/L had a higher cumu- lative all-cause in-hospital mortality (22.4% vs. 0.8%; adjusted odds ratio [aOR], 0.33; 95% [CI]: [0.20–0.55]; p < 0.001). In this study, hemoglobin levels <100 g/L were found to be an independent predictor of in-hospital mortality

    Association between the choice of the conditioning regimen and outcomes of allogeneic hematopoietic cell transplantation for myelofibrosis

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    Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only curative treatment for myelofibrosis. However, the optimal conditioning regimen either with reduced intensity conditioning (RIC) or myeloablative conditioning (MAC) is not well known. Using the Center for International Blood and Marrow Transplant Research database, we identified adults aged ≄18 years with myelofibrosis undergoing allo-HCT between 2008-2019 and analyzed the outcomes separately in the RIC and MAC cohorts based on the conditioning regimens used. Among 872 eligible patients, 493 underwent allo-HCT using RIC (Fludarabine/busulfan=166, Fludarabine/melphalan=327) and 379 using MAC (Fludarabine/busulfan=247, Busulfan/cyclophosphamide=132). In multivariable analysis with RIC, Fludarabine/melphalan was associated with inferior overall survival (HR 1.80, 95% CI 1.15-2.81, p=0.009), higher early non-relapse mortality (HR 1.81, 95% CI 1.12-2.91, p=0.01) and higher acute graft versus host disease (GVHD) (grade II-IV- HR 1.45, 95% CI 1.03-2.03, p=0.03; grade III-IV HR 2.21, 95%CI 1.28-3.83, p=0.004) compared to Fludarabine/busulfan. In the MAC setting, Busulfan/cyclophosphamide was associated with a higher acute GVHD (grade II-IV HR 2.33, 95% CI 1.67-3.25, p\u3c0.001; grade III-IV HR 2.31, 95% CI 1.52-3.52, p\u3c0.001) and inferior GVHD-free relapse-free survival (GRFS) (HR 1.94, 95% CI 1.49-2.53, p\u3c0.001) as compared to Fludarabine/busulfan. Hence, our study suggests that Fludarabine/busulfan is associated with better outcomes in RIC (better overall survival, lower early non-relapse mortality, lower acute GVHD) and MAC (lower acute GVHD and better GRFS) in myelofibrosis

    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
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