960 resultados para Effort musculaire
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Metabolic problems lead to numerous failures during clinical trials, and much effort is now devoted in developing in silico models predicting metabolic stability and metabolites. Such models are well known for cytochromes P450 and some transferases, whereas little has been done to predict the hydrolytic activity of human hydrolases. The present study was undertaken to develop a computational approach able to predict the hydrolysis of novel esters by human carboxylesterase hCES1. The study involves both docking analyses of known substrates to develop predictive models, and molecular dynamics (MD) simulations to reveal the in situ behavior of substrates and products, with particular attention being paid to the influence of their ionization state. The results emphasize some crucial properties of the hCES1 catalytic cavity, confirming that as a trend with several exceptions, hCES1 prefers substrates with relatively smaller and somewhat polar alkyl/aryl groups and larger hydrophobic acyl moieties. The docking results underline the usefulness of the hydrophobic interaction score proposed here, which allows a robust prediction of hCES1 catalysis, while the MD simulations show the different behavior of substrates and products in the enzyme cavity, suggesting in particular that basic substrates interact with the enzyme in their unprotonated form.
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The work carried out during the 4 year research activity can be barely classified in two main lines. On the one hand, a considerable effort is taken to address issues related with the verification of multi-dimensional and transient solutions that are obtained by numerical simulations. Within the studied cases, we can consider cases of piston-cylinder ows within geometries similar to those of hermetic reciprocating compressors.This issue is mentioned in Part I. On the other hand, numerical simulations of different phenomena have been performed. More emphasis has been given to the natural convection ow within enclosures. This is explained in Part II. The case extensively studied has been the natural convection ow. The natural convection ow within enclosures has attracted the attention of many researchers due to its potential to model numerous applications of engineering interest, such as cooling of electronic devices, air ow in buildings, heat transfer in solar collectors, among others. The natural convection studies corresponding to the parallelepipedic enclosures can be classified into two elementary classes: i) heating from a horizontal wall (heating from below); ii) heating from a vertical wall. The characteristic example of the former case is the Rayleigh-B_enard ow, however this research is on the cavities heated from the side. This configuration is referred commonly as the differentially heated cavity.
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Quand on parle de l'acide lactique (aussi connu sous le nom de lactate) une des premières choses qui vient à l'esprit, c'est son implication en cas d'intense activité musculaire. Sa production pendant une activité physique prolongée est associée avec la sensation de fatigue. Il n'est donc pas étonnant que cette molécule ait été longtemps considérée comme un résidu du métabolisme, possiblement toxique et donc à éliminer. En fait, il a été découvert que le lactate joue un rôle prépondérant dans le métabolisme grâce à son fort potentiel énergétique. Le cerveau, en particulier les neurones qui le composent, est un organe très gourmand en énergie. Récemment, il a été démontré que les astrocytes, cellules du cerveau faisant partie de la famille des cellules gliales, utilisent le glucose pour produire du lactate comme source d'énergie et le distribue aux neurones de manière adaptée à leur activité. Cette découverte a renouvelé l'intérêt scientifique pour le lactate. Aujourd'hui, plusieurs études ont démontré l'implication du lactate dans d'autres fonctions de la physiologie cérébrale. Dans le cadre de notre étude, nous nous sommes intéressés au rapport entre neurones et astrocytes avec une attention particulière pour le rôle du lactate. Nous avons découvert que le lactate possède la capacité de modifier la communication entre les neurones. Nous avons aussi décrypté le mécanisme grâce auquel le lactate agit, qui est basé sur un récepteur présent à la surface des neurones. Cette étude montre une fonction jusque-là insoupçonnée du lactate qui a un fort impact sur la compréhension de la relation entre neurones et astrocytes. - Relatively to its volume, the brain uses a large amount of glucose as energy source. Furthermore, a tight link exists between the level of synaptic activity and the consumption of energy equivalents. Astrocytes have been shown to play a central role in the regulation of this so-called neurometabolic coupling. They are thought to deliver the metabolic substrate lactate to neurons in register to glutamatergic activity. The astrocytic uptake of glutamate, released in the synaptic cleft, is the trigger signal that activates an intracellular cascade of events that leads to the production and release of lactate from astrocytes. The main goal of this thesis work was to obtain detailed information on the metabolic and functional interplay between neurons and astrocytes, in particular on the influence of lactate besides its metabolic effects. To gain access to both spatial and temporal aspects of these dynamic interactions, we used optical microscopy associated with specific fluorescent indicators, as well as electrophysiology. In the first part of this thesis, we show that lactate decreases spontaneous neuronal, activity in a concentration-dependent manner and independently of its metabolism. We further identified a receptor-mediated pathway underlying this modulatory action of lactate. This finding constituted a novel mechanism for the modulation of neuronal transmission by lactate. In the second part, we have undergone a characterization of a new pharmacological tool, a high affinity glutamate transporter inhibitor. The finality of this study was to investigate the detailed pharmacological properties of the compound to optimize its use as a suppressor of glutamate signal from neuron to astrocytes. In conclusion, both studies have implications not only for the understanding of the metabolic cooperation between neurons and astrocytes, but also in the context of the glial modulation of neuronal activity. - Par rapport à son volume, le cerveau utilise une quantité massive de glucose comme source d'énergie. De plus, la consommation d'équivalents énergétiques est étroitement liée au niveau d'activité synaptique. Il a été montré que dans ce couplage neurométabolique, un rôle central est joué par les astrocytes. Ces cellules fournissent le lactate, un substrat métabolique, aux neurones de manière adaptée à leur activité glutamatergique. Plus précisément, le glutamate libéré dans la fente synaptique par les neurones, est récupéré par les astrocytes et déclenche ainsi une cascade d'événements intracellulaires qui conduit à la production et libération de lactate. Les travaux de cette thèse ont visé à étudier la relation métabolique et fonctionnelle entre neurones et astrocytes, avec une attention particulière pour des rôles que pourrait avoir le lactate au-delà de sa fonction métabolique. Pour étudier les aspects spatio-temporels de ces interactions dynamiques, nous avons utilisé à la fois la microscopie optique associée à des indicateurs fluorescents spécifiques, ainsi que l'électrophysiologie. Dans la première partie de cette thèse, nous montrons que le lactate diminue l'activité neuronale spontanée de façon concentration-dépendante et indépendamment de son métabolisme. Nous avons identifié l'implication d'un récepteur neuronal au lactate qui sous-tend ce mécanisme de régulation. La découverte de cette signalisation via le lactate constitue un mode d'interaction supplémentaire et nouveau entre neurones et astrocytes. Dans la deuxième partie, nous avons caractérisé un outil pharmacologique, un inhibiteur des transporteurs du glutamate à haute affinité. Le but de cette étude était d'obtenir un agent pharmacologique capable d'interrompre spécifiquement le signal médié par le glutamate entre neurones et astrocytes pouvant permettre de mieux comprendre leur relation. En conclusion, ces études ont une implication non seulement pour la compréhension de la coopération entre neurones et astrocytes mais aussi dans le contexte de la modulation de l'activité neuronale par les cellules gliales.
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This paper argues that women’s absence in peace processes cannot be explained by their alleged lack of experience in dialogue and negotiation, but by a serious lack of will to include them in such important initiatives of change. Women have wide ranging experience in dialogue processes including many war and post-war contexts, but there has been a deliberate lack of effort to integrate them in formal peace processes. After introducing the research framework, the paper addresses women’s involvement in peace, and analyzes the role played by women in peace processes, through the cases of Sri Lanka and Northern Ireland. The paper concludes that peace processes are as gendered as wars, and for that reason gender has to be a guiding line for including women in peace processes.
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Nowadays, service providers in the Cloud offer complex services ready to be used as it was a commodity like water or electricity to their customers with any other extra effort for them. However, providing these services implies a high management effort which requires a lot of human interaction. Furthermore, an efficient resource management mechanism considering only provider's resources is, though necessary, not enough, because the provider's profit is limited by the amount of resources it owns. Dynamically outsourcing resources to other providers in response to demand variation avoids this problem and makes the provider to get more profit. A key technology for achieving these goals is virtualization which facilitates provider's management and provides on-demand virtual environments, which are isolated and consolidated in order to achieve a better utilization of the provider's resources. Nevertheless, dealing with some virtualization capabilities implies an effort for the user in order to take benefit from them. In order to avoid this problem, we are contributing the research community with a virtualized environment manager which aims to provide virtual machines that fulfils with the user requirements. Another challenge is sharing resources among different federated Cloud providers while exploiting the features of virtualization in a new approach for facilitating providers' management. This project aims for reducing provider's costs and at the same time fulfilling the quality of service agreed with the customers while maximizing the provider's revenue. It considers resource management at several layers, namely locally to each node in the provider, among different nodes in the provider, and among different federated providers. This latter layer supports the novel capabilities of outsourcing when the local resources are not enough to fulfil the users demand, and offering resources to other providers when the local resources are underused.
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The dilemma efficiency versus equity, together with political partisan interests, has received increasing attention to explain the territorial allocation of investments. However, centralization intended to introduce or reinforce hierarchization in the political system has not been object as of now of empirical analysis. Our main contribution to the literature is providing evidence that meta-political objectives related to the ordering of political power and administration influence regional investment. In this way, we find evidence that network mode’s (roads and railways) investment programs are influenced by the centralization strategy of investing near to the political capital, while investment effort in no-network modes (airports and ports) appears to be positively related to distance. Since investment in surface transportation infrastructures is much higher than that in airports and ports, and taken into account that regions surrounding the political capital are poorer than the average, we suggest that centralization rather than redistribution has been the driver for the concentration of public investment on these regions.
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ABSTRACT 1. Il existe des données épidémiologiques et expérimentales mettant en lien une carence en fer sans anémie (CF-A) et troubles de la concentration, fatigue, faiblesse musculaire, ainsi que diminution des performances sportives, et ce surtout chez le grand adolescent et l'adulte jeune. Certaines études sont toutefois sujettes à critique, souvent en raison de la présence de facteurs confondants importants associés à la CF-A (niveau d'évidence 1b à 4). Chez l'enfant, les données sont également plus hétérogènes, et d'autant plus difficiles à interpréter que les études à disposition présentent elles-aussi de nombreux facteurs confondants. De manière générale, une certaine prudence doit en conséquence être de mise avant d'attribuer de tels symptômes à une carence en fer (CF).
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Nandrolone (19-nortestosterone) is a widely used anabolic steroid in sports where strength plays an essential role. Once nandrolone has been metabolised, two major metabolites are excreted in urine, 19-norandrosterone (NA) and 19-noretiocholanolone (NE). In 1997, in France, quite a few sportsmen had concentrations of 19-norandrosterone very close to the IOC cut off limit (2ng/ml). At that time, a debate took place about the capability of the human male body to produce by itself these metabolites without any intake of nandrolone or related compounds. The International Football Federation (FIFA) was very concerned with this problematic, especially because the World Cup was about to start in France. In this respect, a statistical study was held with all football players from the first and second divisions of the Swiss Football National League. All players gave a urine sample after effort and around 6% of them showed traces of 19-norandrosterone. These results were compared with amateur football players (control group) and around 6% of them had very small amounts of 19-norandrosterone and/or 19-noretiocholanolone in urine after effort, whereas none of them had detectable traces of one or the other metabolite before effort. The origin of these compounds in urine after a strenuous physical activity is still unknown, but three hypotheses can be put forward. First, an endogenous production of nandrolone metabolites takes place. Second, nandrolone metabolites are released from the fatty tissues after an intake of nandrolone, some related compounds or some contaminated nutritive supplements. Finally, the sportsmen may have taken something during or just before the football game.
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Mycobacterium tuberculosis preferentially resides in mononuclear phagocytes. The mechanisms by which mononuclear phagocytes keep M. tuberculosis in check or by which the microbe evades control to cause disease remain poorly understood. As an initial effort to delineate these mechanisms, we examined by immunostaining the phenotype of mononuclear phagocytes obtained from lungs of patients with active tuberculosis. From August 1994 to March 1995, consecutive patients who had an abnormal chest X-ray, no demostrable acid-fast bacilli in sputum specimens and required a diagnostic bronchoalveolar lavage (BAL) were enrolled. Of the 39 patients enrolled, 21 had microbiologically diagnosed tuberculosis. Thirteen of the 21 tuberculosis patients were either HIV seronegative (n = 12) or had no risk factor for HIV and constituted the tuberculosis group. For comparison, M. tuberculosis negative patients who had BAL samples taken during this time (n = 9) or normal healthy volunteers (n = 3) served as control group. Compared to the control group, the tuberculosis group had significantly higher proportion of cells expressing markers of young monocytes (UCHM1) and RFD7, a marker for phagocytic cells, and increased expression of HLA-DR, a marker of cell activation. In addition, tuberculosis group had significantly higher proportion of cells expressing dendritic cell marker (RFD1) and epithelioid cell marker (RFD9). These data suggest that despite recruitment of monocytes probably from the peripheral blood and local cell activation, host defense of the resident lung cells is insufficient to control M. tuberculosis.
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L'objectiu del projecte ha estat la millora de la qualitat docent de l'assignatura Estructura de Computadors I, impartida a la Facultat d'Informàtica de Barcelona (UPC) dins els estudis d'Enginyeria Informàtica, Enginyeria Tècnica en Informàtica de Sistemes i Enginyeria Tècnica en Informàtica de Gestió. S'ha treballat en quatre línies d'actuació: (i) aplicació de tècniques d'aprenentatge actiu a les classes; (ii) aplicació de tècniques d'aprenentage cooperatiu no presencials; (iii) implantació de noves TIC i adaptació de les ja emprades per tal d'habilitar mecanismes d'autoavaluació i de realimentació de la informació referent a l'avaluació; i (iv) difusió de les experiències derivades de les diferents actuacions. Referent a les dues primeres mesures s'avalua l'impacte de metodologies docents que afavoreixen l'aprenentatge actiu tant de forma presencial com no presencial, obtenint-se clares millores en el rendiment respecte a altres metodologies utilitzades anteriorment enfocades a la realització de classes del tipus magistral, en què únicament es posa a l'abast dels alumnes la documentació de l'assignatura per a què puguin treballar de forma responsable. Les noves metodologies fan especial èmfasi en el treball en grup a classe i la compartició de les experiències fora de classe a través de fòrums de participació. La mesura que ha requerit més esforç en aquest projecte és la tercera, amb el desenvolupament d'un entorn d'interfície web orientat a la correcció automàtica de programes escrits en llenguatge assemblador. Aquest entorn permet l'autoavaluació per part dels alumnes dels exercicis realitzats a l'assignatura, amb obtenció d'informació detallada sobre les errades comeses. El treball realitzat dins d'aquest projecte s'ha publicat en congressos rellevants en l'àrea docent tant a nivell estatal com internacional. El codi font de l'entorn esmentat anteriorment es posa a disposició pública a través d'un enllaç a la web.
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El projecte està associat a l'assignatura de Disseny Microelectrònic I, Troncal de 2on cicle d'Enginyeria en Electrònica a la Universitat de Barcelona. A l'actualitat aquesta assignatura incorpora tant d'estudiants de Física com d'Enginyeries Tècniques d'altres universitats. El seu enfoc és de caire formador pràctic. Temporalment l'assignatura correspon al primer quadrimestre en una carrera que a l'actualitat és només de segon cicle. Per tant correspon a un moment en el qual l'estudiant té el primer contacte amb aquest ensenyament. La introducció de nous conceptes i continguts és constant. Durant els dos anys de durada del projecte, aquest ha permès l’elaboració de material didàctic digital que ha estat incorporat satisfactòriament (ben avaluat per l’alumnat) al material didàctic i les activitats del curs. Un dels objectius principals a aconseguir amb el projecte, combatre el fracàs escolar associat a l’alt índex d’absentisme, s’assoleix amb aquest material. D’altra banda, els alumnes que opten per un seguiment continuat, seguint la metodologia activa del curs, veuen en aquest material el recolzament necessari per afrontar les activitats que se’ls plantegen. En ambdós casos i juntament amb la resta d'activitats presencials del curs, s'aconsegueix incentivar l'autoaprenentatge i motivar l’alumne de forma continuada. El material digital comprèn apunts de l'assignatura i problemes resolts de referència. Durant l’execució del projecte s’ha mesurat contínuament l’esforç de l’estudiant. Aquest era el segon principal objectiu del projecte, sense el qual una adaptació a la metodologia ECTS i a l’EEES és impossible. S'ha mesurat l'esforç que provoquen les diferents activitats, especialment aquelles activitats cooperatives que motiven més l'alumnat però que també el carreguen més. Com a eina per a l'estudiant s'ha desenvolupat un aplicatiu que permet que ell mateix conegui el seu esforç enfront de la resta d'alumnes com a mesura de la seva qualitat d'estudi.
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L'instabilité gléno-humérale revêt de nombreuses formes cliniques. La classification basée sur l'étiologie (lésion de l'appareil capsuloligamentaire ou dysfonction d'origine musculaire) permet d'orienter le traitement. Lors d'Instabilité traumatique, avec récidive de luxation, la réparation chirurgicale donne de bons résultats. Les cas d'instabilité sur dysfonction musculaire, avec composante volontaire, restent du domaine de la rééducation.
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El projecte Statmedia 3 ha consolidat definitivament la proposta de les assignatures Bioestadística de Biologia, Anàlisi de dades de Ciències Ambientals i d’Estadística Matemàtica de la Diplomatura renovant una part del material creat amb Statmedia 2. S’han inclòs a més Matemàtiques d’Ambientals i Introducció a la Probabilitat del Grau d’Estadística. L’anterior MQD abastava només pràctiques mentre que aquest projecte permet una oferta diversa d’activitats individualitzades. La individualització consisteix en que cada estudiant rep una proposta de cas personalitzada amb dades diferents. Les activitats poden ser programades presencialment o no, però la clau de l’èxit de l’activitat és que l’alumne obtingui reconeixement del seu treball en l’avaluació continuada. La valoració que fan als alumnes de Statmedia és molt bo, i observem que es produeix una millora en els resultats acadèmics. Statmedia 3 ha implicat un important esforç en la vessant informàtica del projecte, la barreja de tecnologies que utilitzem son punteres: Ajax, servlets i applets Java... Hem posat a punt un assistent on-line per dissenyar documents i planificar activitats que facilita la tasca dels professors. La nostre participació en primera línea del procés de convergència a l’EEES ens ha permès anticipar alguns canvis, i s’ha traduït en que el claustre del Departament d’Estadística assumís que Statmedia és una metodologia essencial dels seus plans docents. El projecte continua en un quart projecte MQD consecutiu, on desplegarem la nova tecnologia implementada. L’objectiu principal serà dotar a les assignatures dels 7 graus on participa el departament d’activitats individualitzades en forma de casos pràctics, problemes i proves diverses. La col·lecció de material emmagatzemada en la nostra biblioteca, forjada després de quasi deu anys de treball continuat, juntament amb l’experiència acumulada de com utilitzar Statmedia de la forma més eficient han començat a ser explotades en els nous graus aquest mateix curs 2009-2010.
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The initial effort of the Brazilian Ministry of Health to be an active partner in the world effort in the preparation of future accurate human immune deficiency virus (HIV) efficacy trials was the establishment of a multi-centered cohort of homosexual and bisexual men. An open cohort was established to determine the HIV incidence and the socio-behavioral aspects involved in Rio de Janeiro. A total of 318 potential participants, originated from multiple sources (health units, public information, snowball recruitment), were screened and recruitment became effective through the direct involvement of target communities (with the support of Non Governmental Organizations) and the population. Among this group, seropositivity for sexually transmitted diseases was high with 23, 32 and 46% for HIV, syphilis and hepatitis B, respectively. The socio-demographic data from the first 200 participants of this HIV negative cohort suggests that the cohort volunteers are an appropriate sample of the general male population of the State of Rio de Janeiro
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The National Institute of Mental Health developed the semi-structured Diagnostic Interview for Genetic Studies (DIGS) for the assessment of major mood and psychotic disorders and their spectrum conditions. The DIGS was translated into French in a collaborative effort of investigators from sites in France and Switzerland. Inter-rater and test-retest reliability of the French version have been established in a clinical sample in Lausanne. Excellent inter-rater reliability was found for schizophrenia, bipolar disorder, major depression, and unipolar schizoaffective disorder while fair inter-rater reliability was demonstrated for bipolar schizoaffective disorder. Using a six-week test-retest interval, reliability for all diagnoses was found to be fair to good with the exception of bipolar schizoaffective disorder. The lower test-retest reliability was the result of a relatively long test-retest interval that favored incomplete symptom recall. In order to increase reliability for lifetime diagnoses in persons not currently affected, best-estimate procedures using additional sources of diagnostic information such as medical records and reports from relatives should supplement DIGS information in family-genetic studies. Within such a procedure, the DIGS appears to be a useful part of data collection for genetic studies on major mood disorders and schizophrenia in French-speaking populations.