Manifestaciones neurológicas en el adulto con premutación X frágil

Introduction: Fragile X syndrome is an inherited form of mental retardation. It results from an abnormally expanded number of trinucleotide CGG repeats. Some grandfathers of these children become forgetful, have frequent falls and other neurological problems. Researchers have found a connection between fragile X syndrome and the neurological symptoms in elderly men. This resulted in the recognition of a syndrome originally referred to as ‘‘intention tremor, parkinsonism and generalised brain atrophy in carriers of a fragile X premutation’’. This premutation is also associated with premature ovarian failure

Synchronization and optimization of Large Eddy Simulation using an online Ensemble Kalman Filter

An online Data Assimilation strategy based on the Ensemble Kalman Filter (EnKF) is used to improve the predictive capabilities of Large Eddy Simulation (LES) for the analysis of the turbulent flow in a plane channel, $Re_\tau \approx 550$. The algorithm sequentially combines the LES prediction with high-fidelity, sparse instantaneous data obtained from a Direct Numerical Simulation (DNS). It is shown that the procedure provides an augmented state which exhibits higher accuracy than the LES model and it synchronizes with the time evolution of the high-fidelity DNS data if the hyperparameters governing the EnKF are properly chosen. In addition, the data-driven algorithm is able to improve the accuracy of the subgrid-scale model included in the LES, the Smagorinsky model, via the optimization of a free coefficient. However, while the online EnKF strategy is able to reduce the global error of the LES prediction, a discrepancy with the reference DNS data is still observed because of structural flaws of the subgrid-scale model used

La Formación técnica y profesional en Haití : problemas y perspectivas

El presente trabajo ofrece un análisis sobre la problemática de la formación profesional en Haití, considerada primordial para contribuir de forma gradual al desarrollo económico y humano del país. Se identifican los desfases que existen entre la formación profesional ofrecida y la demanda de la sociedad y del mercado laboral, que afectan negativamente la consecución del objetivo de este sector y se proponen soluciones para la reestructuración del sector para asegurarse de que las infraestructuras técnicas y tecnológicas de los centros de formación profesional estén realmente adecuadas, y que los planes de estudio interdisciplinario tengan en cuenta el contexto socio-cultural.El present treball ofereix una anàlisi sobre la problemàtica de la formació professional a Haití, considerada cabdal per contribuir de forma gradual al desenvolupament econòmic i humà del país. S'identifiquen els desfasaments que hi ha entre la formació professional oferida i la demanda de la societat i del mercat laboral, que afecten negativament la consecució de l'objectiu d'aquest sector i es proposen solucions per a la reestructuració del sector per assegurar-se que les infraestructures tècniques i tecnològiques dels centres de formació professional estiguin realment adequades, i que els plans d'estudi interdisciplinari tinguin en compte el context sociocultural

Droits autochtones amazoniens et droit officiel équatorien : une opposition culturelle ?

Le paradoxe de la reconnaissance constitutionnelle de droits aux peuples autochtones réside dans la distinction qu’elle présuppose entre les normativités autochtones et le droit étatique. « Peut-on différencier les droits autochtones amazoniens du droit équatorien officiel en fonction de critères culturels ? ». Cet article propose une réflexion sur cette question. L’analyse de deux cas tirés de quotidiens amazoniens, shiwiar et runa, permet d’établir qu’il est difficile de répondre à cette question de manière affirmative (1) ou négative (2). Pour sortir de ce faux-débat, on interrogera la formulation de cette distinction entre droits autochtones et droit officiel et ce qu’elle suppose en terme de constitutionnalisation (3). Cette porte de sortie invite à penser autrement les relations entre différents « droits » et différentes « cultures » en Amazonie équatorienne (4).The distinction between indigenous law and State law constitutes a paradox for the constitutional recognition of indigenous rights. “Is it possible to differentiate Amazonian indigenous laws from Ecuadorian State law on the basis of cultural criteria ?” This is the issue discussed in the present contribution. The analysis of two cases drawn out runa and shiwiar daily lives conduct to the conclusion that it is impossible to give an affirmative (1) or a negative (2) answer to the question raised by the constitutional text. In order to escape from an impossible debate, we choice to interrogate the constitutional formulation of the distinction between “systems” of state and indigenous laws (3). This way out should allow us to reflect, in a renewed manner, on the relationships between different “rights” and different “cultures” in the Ecuadorian Amazon (4)

Simulation aux grandes échelles et identification acoustique des turbines à gaz en régime partiellement prémélangé

Dans les foyers aéronautiques, une des stratégies adoptée pour réduire l'émission de polluants et faciliter la stabilisation de la flamme, est d'injecter séparément les réactifs dans la chambre de combustion. L'objectif de cette thèse est de développer et de valider l'approche LES (Large Eddy Simulation) de la combustion turbulente partiellement prémélangée dans les turbines à gaz. La conception des nouvelles chambres de combustion moins polluantes, passe par la compréhension de phénomènes instationnaires, tels que les instabilités de combustion. Dans ce contexte, des méthodes pour identifier la réponse de la chambre aux perturbations acoustiques, responsables des instabilités, sont étudiées et améliorées. Dans un premier temps, une étude bibliographique rappelle les caractéristiques essentielles de trois types de combustion rencontrés dans les turbines à gaz (prémélange, diffusion, prémélange partiel). Un état de l'art sur la réduction des schémas cinétiques est proposé à l'issu duquel des schémas cinétiques réduits à deux et quatre étapes sont présentés. Ces schémas ont été développés et validés dans cette thèse. Le modèle de flamme épaissie dynamiquement a été spécialement étendue dans cette thèse aux schémas cinétiques multi-réactions (DTF_MS) en prenant en compte les termes sources de toutes les espèces. Il est intégré dans le code LES AVBP. Ces modèles de combustion doivent prendre en compte les spécificités de la réaction et de l'écoulement: zones de mélange, prémélange à richesse variable, interactions flamme/turbulence, émission de polluants. La deuxième partie décrit les méthodes de mesure des fonctions de transfert. Deux méthodes (FTF et ITM), couramment utilisées numériquement et expérimentalement pour identifier la réponse de la flamme, sont comparées. La formulation FTF est améliorée pour être pleinement compatible avec les approches ITM dans le cadre de l'acoustique linéaire 1D. La troisième partie présente l'étude d'un brûleur propane/air, installé au laboratoire EM2C(Ecole Centrale, Paris). Cette partie représente un premier cas de validation de la LES réactive dans une configuration académique non prémélangée. Les nombreuses comparaisons avec l'expérience permettent de vérifier la qualité de la LES et de mettre en évidence les points à améliorer, en particulier la modélisation de la cinétique. L'évaluation de la réponse instationnaire de la flamme soumise à des perturbations acoustiques est réalisée en comparant les moyennes de phase LES/expérience et en déterminant les fonctions de transfert. Les résultats justifient l'utilisation des méthodes FTF étendues. Enfin, les simulations d'un prototype de brûleur industriel (installé au DLR Institut Technologique de Propulsion à Cologne) ont permis de valider différents points. Tout d'abord, elles montrent que les modèles de combustion sont applicables à une géométrie aussi complexe. Ensuite, elles permettent une première validation des modèles développés dans cette thèse. Les champs moyens obtenus avec deux schémas cinétiques (deux et quatre étapes) sont comparés. Enfin, elles rendent compte de phénomènes instationnaires complexes, tels que les PVC ("Precessing Vortex Core"), les couplages acoustique/hydrodynamique et les instabilités de combustion. ABSTRACT : To reduce pollutant emissions and to better stabilize the flame in modern aeroengine combustors, a common strategy is to inject fuel and oxidizer separately. The aim of this thesis is first to develop and to validate the large eddy simulation (LES) of turbulent partially premixed combustion in gaz turbines. The design of new combustion chambers with low level emissions requires the understanding of unsteady phenomena, like combustion instabilities. In this study, two methods for identifying the chamber response to acoustic perturbations are investigated. In the first part, the three types of combustion (premixed, diffusion partially premixed), which are found in combustors are briefly described. Then a state of the art in kinetic scheme reduction techniques is given, followed by the description of a 2-step and a 4-step reduced kinetic schemes, that have been developed and validated for this study. Then, a dynamically thickened flame model (DTF_MS) has been specially developed in the thesis for multi-step reaction schemes. It has been integrated in the LES code AVBP. These models take into account the features of the flow and of the reaction: mixing zones, variable equivalence ratios, flame/turbulence interactions, pollutant emissions. In the second part, methods for measuring flame transfer functions are detailed. Two methods (FTF and ITM) are usually used numerically and experimentally, to identify the unsteady flame response. The FTF formulation is extended to be fully compatible with the approach ITM in the 1D linear acoustic analysis. In the third part, a propane/air burner set up at EM2C laboratory (Ecole Centrale, Paris) is presented. This part is dedicated to the first validation of reactive LES in an academic non premixed configuration. The many comparisons with experiments are used to check the accuracy of LES and to evidence results that need to be improved. The evaluation of the response of the flame under acoustic forcing is realised comparing simulation and experiments in terms of phase average fields and flame transfer functions. Results show that extended FTF methods are needed. Finally, simulations of the prototype of an industrial burner (installed in DLR Institute of Propulsion Technology) are used to validate some points. First, the combustion models can be applied in a complex geometry. Second, this part provides a first validation of the combustion models developed in this thesis. The mean fields obtained with two kinetic schemes (2 and 4 steps) are compared. Third, complex unsteady phenomena, like PVC ("precessing vortex core"), acoustics/hydrodynamics coupling and combustion instabilities, can be captured by LE

Du malentendu juridique

Dans cet article, nous nous proposons de décrire la façon dont différentes figures de mécompréhension sont attribuées par des imputations hypothétiques mobilisées au sein et à propos d’une audience de justice de paix. En prenant soin de mettre en avant le matériau empirique – présenté sous forme de « scènes » – et en n’oubliant pas d’inclure la position occupée par le chercheur dans la réflexion, notre objectif est de montrer que, loin de constituer des obstacles nécessitant d’être levés, les imputations de malentendu, de méprise et de mensonge sont des ressources discursives employées aussi bien dans le contexte de la mésentente conjugale, que dans ceux du processus décisionnel juridique et de l’interprétation scientifique « ex situ ». A l’encontre de l’idée que le droit serait, en pratique ou en théorie, largement incompatible avec le malentendu, nous affirmons que ce dernier constitue toujours une clé d’interprétation possible d’une mésentente persistante et que, bien plus que sa levée ou sa prévention, c’est son déplacement, sa reconfiguration ou son ajournement qu’il faut envisager dans l’exercice du droit.This paper describes different figures of misunderstandings and hypothetical imputations made by the actors of a judicial hearing (Belgian Justice of the Peace Court). In doing so, we aim to demonstrate that far from being obstacles that should be cleared up, the imputations of misunderstandings, errors and lies constitute primary discursive means which are continuously at work : here in conjugal dispute, judicial decisional process but also in any scientific effort of “ex situ” interpretation. Against the idea that law – in practice or in theory – is at odds with misunderstanding, we conceive the latter as being always a key interpretation for any persisting disagreement. Therefore, law and its application have to be thought as allowing the displacement, reconfiguration or postponement of misunderstandings rather than their avoidance or resolution

Large-eddy simulation analysis of knock in a direct injection spark ignition engine

International audienceDownsized spark ignition (SI) engines running under high loads have become more and more attractive for car manufacturers because of their increased thermal efficiency and lower CO2 emissions. However, the occurrence of abnormal combustions promoted by the thermodynamic conditions encountered in such engines limits their practical operating range, especially in high efficiency and low fuel consumption regions. One of the main abnormal combustion is knock, which corresponds to an autoignition of end gases during the flame propagation initiated by the spark plug. Knock generates pressure waves which can have long term damages on the engine, that is why the aim for car manufacturers is to better understand and predict knock appearance. However an experimental study of such recurrent but non-cyclic phenomena is very complex, and these difficulties motivate the use of CFD for better understanding them. In the present paper, Large-Eddy Simulation (LES) is used as it is able to represent the instantaneous engine behavior and thus to quantitatively capture cyclic variability and knock. The proposed study focuses on the LES analysis of knock for a direct injection SI engine. A spark timing sweep available in the experimental database is simulated, and 15 LES cycles were performed for each spark timing. Wall temperatures, which are a first order parameter for knock prediction, are obtained using a conjugate heat transfer study. Present work points out that LES is able to describe the in-cylinder pressure envelope whatever the spark timing, even if the sample of LES cycles is limited compared to the 500 cycles recorded in the engine test bench. The influence of direct injection and equivalence ratio stratifications on combustion is also analyzed. Finally, focusing on knock, a MAPO (Maximum Amplitude Pressure Oscillation) analysis is conducted for both experimental and numerical pressure traces pointing out that LES well reproduces experimental knock tendencies

Large Eddy Simulation of combustion instabilities in a lean partially premixed swirled flame

This paper investigates one issue related to Large Eddy Simulations (LES) of self- excited combustion instabilities in gas-fueled swirled burners: the effects of incom- plete mixing between the gas injection and the combustion chamber. For simplicity reasons, many LES assume perfect premixing of the gases entering the combustion chamber. In practice this is rarely the case and this study addresses the question by comparing LES assuming perfect premixing and LES where the fuel jets are resolved and fuel/air mixing is explicitely computed. This is done for the Preccin- sta swirled burner which has been carefully studied experimentally at DLR. All previous LES studies of Preccinsta have assumed perfect premixing and this work demonstrates that this assumption is reasonable for stable flows but is not accept- able to predict self-excited unstable cases. This is shown by comparing LES and experimental fields in terms of mean and RMS fields of temperature, species and velocities as well as mixture fraction pdfs and unsteady activity for two regimes: a stable one at equivalence ratio 0.83 and an unstable one at 0.7

Uncertainty and Sensitivity Analysis in Turbulent Pipe Flow Simulation

In this study, we would like to evaluate and improve the performance of Wall-Modeled LargeEddy Simulation (WMLES) on the modeling of a pipe flow for which Direct Numerical Simulation (DNS) data is available [1] and considered as a reference for further comparisons. Models used in WMLES may raise problems of accuracy which come from the uncertain values of model parameters and model simplifications. In this study, we focus firstly on the impact of the model parameter uncertainties on the simulation results, and then on the reduction of these uncertainties via data calibration. These studies using sampling-based approaches can be unaffordable when coupled with a high-fidelity simulation that requires several CPU hours for a single execution. To reduce the computational cost while maintaining a target accuracy, we propose to build surrogate models based on Gaussian Processes for simulations outputs, and replace the simulator for evaluating the large size sampled sets. For this study, a CFD-UQ methodology is developed which couples our internal UQ tool and a CFD solver. It has been applied on a turbulent pipe flow case that allows us to validate its implementation

Distal Radius Fracture Treated by Internal Fixation with Plates, Screws and the RALCA® External Mini-fixator

Distal radius fractures are very common in medical practice. In our service, we may not have the most widely used devices for fixation of these fractures at a given moment. For this reason, we must consider all possible combinations within our power to correct them since most of the time, it is impossible to maintain a fracture reduction using a single technique. We present the case of a 24-year-old female patient treated at the Dr. Gustavo Aldereguía Lima University General Hospital in Cienfuegos due to a displaced fracture of the left distal radius caused by impaction. It was successfully stabilized by internal fixation with plates, screws and the RALCA® external mini-fixator