Shp2 régule la phosphorylation des tyrosines de l'arrestine

Les arrestines sont connues pour leurs rôles dans la désensibilisation et l'endocytose des récepteurs couplés aux protéines G (RCPGs). Au fil des ans, plusieurs partenaires de ces protéines adaptatrices ont été identifiés, notamment diverses molécules impliquées dans la signalisation, incluant les kinases ERK, JNK, Akt, Raf et Src. Ainsi, les arrestines interagissent avec plusieurs kinases, mais seulement avec deux phosphatases, PPA2 et MKP7. Récemment, notre laboratoire a démontré une nouvelle interaction entre les arrestines non-visuelles et la phosphatase Shp2. En effet, des essais in vitro et in cellulo ont montré une interaction directe entre les deux protéines peuvent interagir ensembles et ce directement. Or, nous en sommes venus à nous demander si les arrestines peuvent être phosphorylées sur leurs résidus tyrosine et si cette modification pourrait être régulée par des partenaires connus, soient Src et Shp2. Il a déjà été montré que l'arrestine 2 peut être phosphorylée sur un résidu tyrosine qui lui est unique et que cette modification expliquerait peut-être les différences de modulation entre les arrestines non-visuelles. Par contre, il n'existe encore aucune preuve que l'arrestine 3 puisse aussi être phosphorylée. D'abord, nous démontrons pour la première fois que l'arrestine 3, tout comme l'arrestine 2, est phosphorylée sur des résidus tyrosines et que cette modification peut être amenée par l'activité de Src. Ensuite, un double mutant ponctuel de l'arrestine 3 a été construit afin de cibler les tyrosines régulées. Il semble que les tyrosines 380 et 404 de l'arrestine 3, soient d'importants sites de phosphorylation. Ce nouveau mutant de l'arrestine 3 représente un excellent outil afin de déterminer le rôle de la phosphorylation des tyrosines de l'arrestine 3. Aussi, puisque ces deux tyrosines sont absentes de la séquence de l'arrestine 2, leur phosphorylation pourrait être à la base des différences fonctionnelles entre les arrestines 2 et 3. De plus, nous faisons la démonstration, en conditions de surexpression en cellules, que l'activité de Shp2 peut mener à la déphosphorylation des arrestines non-visuelles. Dès lors, nos études montrent d'abord que, tout comme son homologue, l'arrestine 3 peut être phosphorylée sur ses tyrosines. De plus, cette phosphorylation est non seulement régulée par la phosphatase Shp2, mais représente également un nouveau mécanisme potentiel de régulation des multiples fonctions des arrestines

Effects of Three Training Methods on the Physical Fitness in Adult Cameroonian Boxers

This study aimed to evaluate three training methods on the physical capacity of Cameroonians boxers in other to propose the best method for their preparation. Thus, thirty-six boxers aged twenty-three to twenty-six were recruited and divided into three groups of twelve boxers each. They were submitted to training session for eight weeks using the continuous method, the intermittent method and the mixed method for group one, two and three respectively. Anthropometric (weight, height and Body Mass Index (BMI)) and physiological (Maximal Oxygen Consumption (VO2max), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Blood Glucose Levels (BGL) and Blood Lactic Acid concentrations (BLA)) parameters were measured before and after the training session program. Results at the end of the program showed no significant variation of Blood Glucose Level of boxers between the three groups as well as inside the same group (p>0.05). On the other hand, significant differences (p<0.05-p<0.001) in weight, BMI, SBP, DBP, VO2max and Blood Lactic Acid concentrations were observed. Indeed, weight, BMI, SBP and DBP decreased significantly (p<0.05-p<0.001), while VO2max increased significantly in the three experimental groups (p<0.05-p<0.001). The analysis of these results reveals that the group having practiced the mixed training method showed the strongest rates of increase in VO2max (67.8±5.00 ml/min/kg). In addition, their VO2max at the end of the experimentation is largely above the average value defined by literature (64.8 ml/min/kg). This can justify the choice of the mixed training method for the physical preparation of Cameroonian boxers

Improvement in the amino-acid microbial production

Amino-acid microbial production can be improved by a process modification or by inducing changes in the metabolism of the biocatalyst. These two approaches will be illustrated and discussed using the examples of glutamic acid and valine productions with Corynebacterium glutamicum.La production d'acide aminé par voie microbienne peut être améliorée soit en jouant sur le procédé de culture soit en modifiant le métabolisme du micro-organisme producteur. Ces 2 approches seront illustrées et discutées grâce à deux exemples d'acides aminés produits par Coryne-bacterium glutamicum: l'acide glutamique et la valine

De la place des savoirs grammaticaux et lexicaux dans les référentiels de compétences et dans certaines manuels contemporains de langues modernes

Cette communication aborde dans un premier temps la place des savoirs grammaticaux et lexicaux dans les prescrits légaux en FWB (Socles de compétences et Compétences terminales et savoirs requis en langues modernes). Dans un deuxième temps, nous analysons la place de ces savoirs dans deux manuels de langues (Tandem et Headway). Dans la conclusion, nous proposons quelques pistes pour a) optimiser l'Approche par Compétences préconisée en FWB et b) la rendre plus équitable.Peer reviewe

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

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

Incentivizing the Dynamic Workforce: Learning Contracts in the Gig-Economy

In principal-agent models, a principal offers a contract to an agent to perform a certain task. The agent exerts a level of effort that maximizes her utility. The principal is oblivious to the agent's chosen level of effort, and conditions her wage only on possible outcomes. In this work, we consider a model in which the principal is unaware of the agent's utility and action space. She sequentially offers contracts to identical agents, and observes the resulting outcomes. We present an algorithm for learning the optimal contract under mild assumptions. We bound the number of samples needed for the principal obtain a contract that is within $\epsilon$ of her optimal net profit for every $\epsilon>0$

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

School organizational culture: The peak of research in the context of neoliberal policies

Inscrita numa matriz teórica multirreferencial, a problemática da cultura organizacional tem sido objecto de múltiplos desenvolvimentos conceptuais e diversificadas apropriações políticas e ideológicas. No campo da educação e no contexto mais específico das organizações escolares, as abordagens culturais e simbólicas sofreram algumas inflexões teóricas apenas compreensíveis quando contextualizadas no quadro mais global das políticas internacionais de cariz neoliberal e neoconservador. Neste trabalho, procura-se reflectir criticamente sobre a forma como a problemática da cultura organizacional em contexto escolar passa a ser (re)perspectivada numa altura em que se expandem alguns objectivos e valores políticos associados às ideologias da modernização e da racionalização. Num segundo momento, tomando como ponto de partida a análise de um vasto número de investigações integradas em quatro bases de dados electrónicas de âmbito internacional, debatemos as principais tendências teóricas, conceptuais e metodológicas deste campo de estudo, fazendo sobressair o lugar e o estatuto da escola enquanto contexto privilegiado de investigação, designadamente nos domínios crítico-reflexivos.Within a multi-referential theoretical framework, the issue of organizational culture has been a subject for multiple conceptual developments and different ideological and political appropriations. In the field of education and in the specific context of school organizations, the cultural and symbolic approaches were subjected to some theoretical inflections. These can only be understood in the global framework of international policies of neoliberal and neoconservative nature. First, this paper critically discusses how the issue of organizational culture in school context was put in perspectives at a time when some political-ideological objectives and values were associated to modernization and rationalization ideologies. Based on the analysis of a great number of researches included in four electronic databases with an international scope, it then discusses the main theoretical, conceptual and methodological trends of this field of study, stressing the place and statute of school as a privileged research context, namely in the reflexive and critical domain.info:eu-repo/semantics/publishedVersio

Nitrification d'un effluent minier sur lit de calcaire

Microbiologie de la nitrification -- dénitrification -- Revue des procédés de nitrification -- dénitrification par domaine d'application -- Traitement de l'eau potable -- Traitement des eaux usées -- Traitement de l'eau souterraine -- Traitement de l'eau minière -- Évaluation économique préliminaire de nitrification -- dénitrification pour deux mines -- Estimation du potentiel de réduction du coût d'opération avec l'utilisation de substrats alternatifs au bicarbonate de soude et au méthanol -- Estimation du potentiel de réduction des coûts en capital pour des procédés alternatifs au lit fixe -- Solution d'alimentation et amendement -- Montage expérimental -- Caractérisation du matériau immobilisant -- Démarrage et enlèvement de l'excès de biomasse -- Description des tests -- Description de méthodes d'analyse -- Comparaison entre le calcaire et le sable comme milieu immobilisant pour la nitrification -- Dissolution du lit calcaire -- Optimisation des conditions d'opérations -- Comparaison de la performance des lits de calcaire et de sable -- Paramètres de conception et d'opération -- Sursaturation en CO2 de l'eau testée -- Évaluation des dimensions d'un réacteur à pleine échelle pour la mine Holloway