• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 306
  • 96
  • 41
  • 24
  • 17
  • 11
  • 9
  • 6
  • 5
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 614
  • 318
  • 204
  • 170
  • 140
  • 115
  • 102
  • 101
  • 88
  • 77
  • 65
  • 56
  • 55
  • 55
  • 54
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Modélisation de l'interprétation des pianistes & applications d'auto-encodeurs sur des modèles temporels

Lauly, Stanislas 04 1900 (has links)
Ce mémoire traite d'abord du problème de la modélisation de l'interprétation des pianistes à l'aide de l'apprentissage machine. Il s'occupe ensuite de présenter de nouveaux modèles temporels qui utilisent des auto-encodeurs pour améliorer l'apprentissage de séquences. Dans un premier temps, nous présentons le travail préalablement fait dans le domaine de la modélisation de l'expressivité musicale, notamment les modèles statistiques du professeur Widmer. Nous parlons ensuite de notre ensemble de données, unique au monde, qu'il a été nécessaire de créer pour accomplir notre tâche. Cet ensemble est composé de 13 pianistes différents enregistrés sur le fameux piano Bösendorfer 290SE. Enfin, nous expliquons en détail les résultats de l'apprentissage de réseaux de neurones et de réseaux de neurones récurrents. Ceux-ci sont appliqués sur les données mentionnées pour apprendre les variations expressives propres à un style de musique. Dans un deuxième temps, ce mémoire aborde la découverte de modèles statistiques expérimentaux qui impliquent l'utilisation d'auto-encodeurs sur des réseaux de neurones récurrents. Pour pouvoir tester la limite de leur capacité d'apprentissage, nous utilisons deux ensembles de données artificielles développées à l'Université de Toronto. / This thesis addresses the problem of modeling pianists' interpretations using machine learning, and presents new models that use temporal auto-encoders to improve their learning for sequences. We present previous work in the field of modeling musical expression, including Professor Widmer's statistical models. We then discuss our unique dataset created specifically for our task. This dataset is composed of 13 different pianists recorded on the famous Bösendorfer 290SE piano. Finally, we present the learning results of neural networks and recurrent neural networks in detail. These algorithms are applied to the dataset to learn expressive variations specific to a style of music. We also present novel statistical models involving the use of auto-encoders in recurrent neural networks. To test the limits of these algorithms' ability to learn, we use two artificial datasets developed at the University of Toronto.
492

Épidémiologie spatiale de la campylobactériose au Québec

Arsenault, Julie 08 1900 (has links)
La campylobactériose représente la principale cause de gastro-entérite bactérienne dans les pays industrialisés. L’épidémiologie de la maladie est complexe, impliquant plusieurs sources et voies de transmission. L’objectif principal de ce projet était d’étudier les facteurs environnementaux impliqués dans le risque de campylobactériose et les aspects méthodologiques pertinents à cette problématique à partir des cas humains déclarés au Québec (Canada) entre 1996 et 2006. Un schéma conceptuel des sources et voies de transmission de Campylobacter a d’abord été proposé suivant une synthèse des connaissances épidémiologiques tirées d’une revue de littérature extensive. Le risque d’une récurrence de campylobactériose a ensuite été décrit selon les caractéristiques des patients à partir de tables de survie et de modèles de régression logistique. Comparativement au risque de campylobactériose dans la population générale, le risque d’un épisode récurrent était plus élevé pour les quatre années suivant un épisode. Ce risque était similaire entre les genres, mais plus élevé pour les personnes de régions rurales et plus faible pour les enfants de moins de quatre ans. Ces résultats suggèrent une absence d’immunité durable ou de résilience clinique suivant un épisode déclaré et/ou une ré-exposition périodique. L’objectif suivant portait sur le choix de l’unité géographique dans les études écologiques. Neuf critères mesurables ont été proposés, couvrant la pertinence biologique, la communicabilité, l’accès aux données, la distribution des variables d’exposition, des cas et de la population, ainsi que la forme de l’unité. Ces critères ont été appliqués à des unités géographiques dérivées de cadre administratif, sanitaire ou naturel. La municipalité affichait la meilleure performance, étant donné les objectifs spécifiques considérés. Les associations entre l’incidence de campylobactériose et diverses variables (densité de volailles, densité de ruminants, abattoirs, température, précipitations, densité de population, pourcentage de diplomation) ont ensuite été comparées pour sept unités géographiques différentes en utilisant des modèles conditionnels autorégressifs. Le nombre de variables statistiquement significatives variait selon le degré d’agrégation, mais la direction des associations était constante. Les unités plus agrégées tendaient à démontrer des forces d’association plus élevées, mais plus variables, à l’exception de l’abattoir. Cette étude a souligné l’importance du choix de l’unité géographique d’analyse lors d’une utilisation d’un devis d’étude écologique. Finalement, les associations entre l’incidence de campylobactériose et des caractéristiques environnementales ont été décrites selon quatre groupes d’âge et deux périodes saisonnières d’après une étude écologique. Un modèle de Poisson multi-niveau a été utilisé pour la modélisation, avec la municipalité comme unité. Une densité de ruminant élevée était positivement associée avec l’incidence de campylobactériose, avec une force d’association diminuant selon l’âge. Une densité de volailles élevée et la présence d’un abattoir de volailles à fort volume d’abattage étaient également associées à une incidence plus élevée, mais seulement pour les personnes de 16 à 34 ans. Des associations ont également été détectées avec la densité de population et les précipitations. À l’exception de la densité de population, les associations étaient constantes entre les périodes saisonnières. Un contact étroit avec les animaux de ferme explique le plus vraisemblablement les associations trouvées. La spécificité d’âge et de saison devrait être considérée dans les études futures sur la campylobactériose et dans l’élaboration de mesures préventives. / Campylobacteriosis is a leading cause of acute bacterial gastro-enteritis in industrialized countries. The epidemiology of the disease is complex, involving many sources and transmission pathways. The principal objective of this project was to study environmental factors and methodological aspects pertinent to the spatial epidemiology of human campylobacteriosis using cases reported in Quebec (Canada) between 1996 and 2006. A conceptual diagram of sources and transmission pathways of Campylobacter was first proposed following a synthesis of current epidemiological knowledge based on a comprehensive literature review. The risk of recurrent episodes in relation to patient characteristics was described. Life table estimates and logistic regression were used for modeling. Compared to campylobacteriosis risk in the general population, the risk for a recurrent disease event was higher for a period of four years with a decreasing trend. This increased risk was similar across gender but higher for people from rural areas and lower for children under four years old. These results may suggest the absence of durable immunity or clinical resilience following a first episode and/or periodic re-exposure, at least among reported cases. Next, criteria were proposed and applied to ascertain the best geographical unit to use. Nine measurable criteria were proposed, including biological relevance, communicability of results, ease of data access, distribution of exposure variables, cases and population, and unit shape. These criteria were applied to various geographical units derived from administrative, health services and natural frameworks. Ultimately, the municipal geographical unit performed the best, given the specific objectives of the study. Future research areas for optimizing the choice of geographical unit were discussed. Another objective was to estimate and compare the associations between incidence and various environmental characteristics (poultry density, ruminant density, slaughterhouse, temperature, and precipitation) and demographic characteristics (population density, diploma) using seven different geographical units. Conditional autoregressive models were used for statistical modeling. In general, the number of significant predictors decreased as the aggregation level increased but directions of associations were consistent. More aggregated scales tended to show larger but more variable estimates for all variables, with the exception of the presence of slaughterhouses. This study highlighted the need for careful selection and analysis of geographical units when using ecological designs in epidemiological studies. Finally, the association between environmental characteristics and incidence in relation to four age groups and deux seasonal periods was studied. A multi-level Poisson regression model was used for modeling at the municipal level. High ruminant density was positively associated with incidence but decreased with age. High poultry density and presence of a large poultry slaughterhouse were also associated with higher incidence for people aged 16-34. Associations were also detected with population density and average daily precipitation. Except for population density, associations were constant across seasonal periods. Close contact with farm animals is most likely involved in the associations observed. Clearly, age and season must be considered in future studies on campylobacteriosis and in the design of preventive measures.
493

Subepithelial collagen content in the peripheral airways of heaves-affected and control horses

Setlakwe, Emilie L. 04 1900 (has links)
Chez les patients asthmatiques, on retrouve un remodelage de la matrice extracellulaire des poumons, caractérisé par une augmentation du collagène ou fibrose de la couche sous-épithéliale des voies respiratoires. Le souffle, maladie inflammatoire chronique des voies respiratoires inférieures des chevaux matures, présente des similarités physiopathologiques avec l’asthme humain, incluant le remodelage. Ceci nous conduit à l’hypothèse que la fibrose de la couche sous-épithéliale pourrait être une composante des lésions pulmonaires chez les chevaux affectés, ce que notre étude avait pour objectif d’évaluer. Des biopsies pulmonaires périphériques réalisées par voie thoracoscopique ont été obtenues chez 5 chevaux témoins et 6 chevaux atteints du souffle, avant (T0) et après une stimulation antigénique de 30 jours avec du foin moisi et de la paille. Avant le début de l’étude, les sujets étaient en rémission clinique et ne démontraient aucun signe clinique de maladie. Un examen microscopique des échantillons prélevés a été réalisé après traitement au picrosirius-rouge, colorant spécifique des fibres de collagène. La surface du collagène de la couche sous-épithéliale a été mesurée et corrigée en fonction de la taille de la voie respiratoire en utilisant des techniques morphométriques standards. Les chevaux atteints de souffle ont une surface de collagène plus grande dans la couche sous-épithéliale (p<0.1) en comparaison avec les chevaux témoins. La fibrose de la couche sous-épithéliale demeure inchangée chez les chevaux malades après la stimulation antigénique de 30 jours. À T0, la fibrose de la couche sous-épithéliale est associée positivement aux variations maximales de pression pleurale et à la résistance pulmonaire chez les chevaux atteints de souffle. Les résultats de cette étude suggèrent qu’une fibrose de la couche sous-épithéliale est présente dans les voies respiratoires périphériques des chevaux atteints de souffle et contribue au déficit de fonction résiduel pulmonaire observé lors de rémission clinique. / Extracellular matrix remodelling is present in the human asthmatic lung, and is characterized by increased collagen or fibrosis of the subepithelial area of the airway. Heaves, a naturally occurring chronic lower airway inflammatory condition in horses shares aspects of pathophysiology with asthma, including features of airway remodelling. We thus hypothesize that airway fibrosis is a characteristic of remodelling in heaves. The aim of this study was to evaluate the presence of fibrosis in the subepithelial area of the peripheral airways of heaves-affected horses. Peripheral lung biopsies acquired under thoracoscopic guidance were obtained from 5 control and 6 heaves-affected horses, both before (T0) and after a 30 day antigenic challenge with mouldy hay and straw. Prior to the study, diseased horses were in clinical remission and exhibited no clinical signs of disease. Obtained samples were microscopically examined using picrosirius-red, a collagen specific histological staining technique. Collagen area in the subepithelial layer, e.g. the region between the airway smooth muscle and the epithelial layer was measured, and corrected for airway size using standard morphometric techniques. In comparison with controls, heaves-affected horses had an increased collagen content in the airway subepithelial area (p<0.1). No change in fibrosis of the subepithelial area was observed in diseased horses after the 30 day antigenic challenge. Peripheral airway subepithelial collagen at baseline was positively associated with maximal changes in transpulmonary pressure and pulmonary resistance in horses with heaves but not in controls. Results of this study indicate that fibrosis of the subepithelial area is present in the peripheral airways of heaves-affected horses, and may play a role in residual lung function deficits observed in diseased horses even while in clinical remission.
494

Structural rules for the formation of backbone-backbone interactions between closely packed RNA double helices

Tao, Fatou 04 1900 (has links)
Les interactions entre les squelettes sucre-phosphate de nucléotides jouent un rôle important dans la stabilisation des structures tertiaires de larges molécules d’ARN. Elles sont régies par des règles particulières qui gouverne leur formation mais qui jusque là demeure quasiment inconnues. Un élément structural d’ARN pour lequel les interactions sucre-phosphate sont importantes est le motif d’empaquetage de deux doubles hélices d’ARN le long du sillon mineur. Ce motif se trouve à divers endroits dans la structure du ribosome. Il consiste en deux doubles hélices interagissant de manière à ce que le squelette sucre-phosphate de l’une se niche dans le sillon mineur de l’autre et vice versa. La surface de contact entre les deux hélices est majoritairement formée par les riboses et implique au total douze nucléotides. La présente thèse a pour but d’analyser la structure interne de ce motif et sa dépendance de stabilité résultant de l’association optimale ou non des hélices, selon leurs séquences nucléotidiques. Il est démontré dans cette thèse qu’un positionnement approprié des riboses leur permet de former des contacts inter-hélices, par l’entremise d’un choix particulier de l’identité des pairs de bases impliquées. Pour différentes pairs de bases participant à ce contact inter-hélices, l’identité optimale peut être du type Watson-Crick, GC/CG, or certaines pairs de bases non Watson-Crick. Le choix adéquat de paires de bases fournit une interaction inter-hélice stable. Dans quelques cas du motif, l’identité de certaines paires de bases ne correspond pas à la structure la plus stable, ce qui pourrait refléter le fait que ces motifs devraient avoir une liberté de formation et de déformation lors du fonctionnement du ribosome. / Although backbone-backbone interactions play an important role in stabilization of the tertiary structure of large RNA molecules, the particular rules that govern the formation of these interactions remain basically unknown. One RNA structural element for which the backbone-backbone interactions are essential is the along-groove packing motif. This motif is found in numerous locations in the ribosome structure; it consists of two double helices arranged such that the backbone of one helix is packed in the minor groove of the other helix and vice versa. The contact area between the two helices is mostly formed by riboses and totally involves twelve nucleotides. Here we analyze the internal structure of the along-groove packing motif and the dependence of stability of the association of the helices on their nucleotide sequences. We show that the proper positioning of the riboses that allows them to form inter-helix contacts is achieved through the particular choice of the identities of the base pairs involved. For different base pairs participating in the inter-helix contacts the optimal identities can be Watson-Crick, GC/CG, or certain non-Watson-Crick base pairs. The proper choice of the base pairs provides for the stable inter-helix interaction. In some cases of the motif, the identities of certain base pairs do not correspond to the most stable structure, which may reflect the fact that these motifs should break and form during the ribosome function.
495

Contributions à la prévision court-terme, multi-échelle et multi-variée, par apprentissage statistique du trafic routier / Contributions to the short-term, multi-variate and multi-scale prediction of traffic states based on machine learning methods

Laharotte, Pierre-Antoine 16 December 2016 (has links)
La maturité de la télématique et des technologies de l’information et la communication (TIC), ainsi que l’avènement du big data dans le transport ont conduit à des développements foisonnants dans le domaine des systèmes de transports intelligents (ITS), aussi bien sur le plan des technologies de recueil que du traitement innovant de l’information. Il est désormais possible de connaître les conditions de circulation et les états de trafic sur la plupart des sections d’un réseau routier sans avoir recours à des infrastructures intrusives de collecte de données, de transmettre l’information résultante via des réseaux sans fil et de traiter rapidement toutes ces données multi-sources disponibles. La constitution de grandes bases de données a naturellement fait évoluer la pratique de gestion du trafic et plus particulièrement les méthodes de prévision. Ces méthodes ont connu un renouveau en s’inspirant des travaux produits en apprentissage statistique. Néanmoins, la façon d’appréhender le problème de la prévision est restée à une échelle locale. Pour chaque section de route, un modèle de prévision est adapté et optimisé. Notre travail de thèse présente un cadre de prévision du trafic routier qui aborde la question à l’échelle du réseau. L’étude menée au sein de ces travaux de thèse vise à exposer et évaluer cette nouvelle approche, dite globale, au regard d’approches usuelles, puis à analyser sa sensibilité vis-à-vis de divers facteurs. Après un positionnement par rapport à l’état de l’art en théorie du trafic, le cadre prédictif fondé sur des méthodes de prévision multi-variées par apprentissage est détaillé. Une version multidimensionnelle des k plus proches voisins, modèle parcimonieux et simple, est évaluée sur divers cas d’études. L’originalité réside dans l’exploitation de données issues de méthodes innovantes de collecte (e.g. Bluetooth, véhicules traceurs, véhicules connectés). Par la suite, les performances de l’approche initiale sont comparées à d’autres méthodes d’apprentissage. Un effort particulier est porté sur l’adaptation de méthodes à noyaux au cadre prédictif global. Les performances obtenues laissent entrevoir une typologie des méthodes en fonction des caractéristiques spatiotemporelles du réseau. Afin d’améliorer les performances en prévision et de réduire les temps de calcul, une méthode d’identification et de sélection des sections critiques du réseau est proposée. Les résultats prouvent qu’un sous-ensemble restreint de sections est en effet suffisant pour garantir des performances satisfaisantes en généralisation. Enfin, la résilience du cadre prédictif est évaluée au regard des événements non récurrents affectant le fonctionnement nominal du réseau, comme des incidents ou des conditions météorologiques dégradées. Les résultats soulignent l’impact de ces conditions non récurrentes sur la prévision temps-réel de la dynamique court-terme d’un réseau et permettent de dresser une feuille de route pour l’élaboration d’un cadre prédictif résilient et opérationnel. Cette nouvelle vision de la prévision s’inscrit dans les perspectives actuelles en termes d’applications sur les modules embarqués et les objectifs des gestionnaires d’infrastructures. / The maturity of information and communication technologies and the advent of Big Data have led to substantial developments in intelligent transportation systems (ITS) : from data collection to innovative processing solutions. Knowledge of current traffic states is available over most of the network range without the use of intrusive infrastructure-side collection devices, instead relying on wireless transmission of multi-source data. The increasing use of huge databases had a strong influence on traffic management, including forecasting methods. These approaches followed the recent trend towards innovative works on statistical learning. However, the prediction problem remains mainly focused on the local scale. The prediction for each road link relies on a dedicated, optimized and adapted prediction model. Our work introduces a traffic-forecasting framework able to tackle network scale problems. The study conducted in this thesis aims to present and evaluate this new “global” approach, in comparison to most-used existing works, and then to analyze its sensitivity to several factors. The traffic-forecasting framework, based on multi-variate learning methods, is detailed after a review of the literature on traffic flow theory. A multi-dimensional version of the k nearest-neighbors, a simple and sparse model, is evaluated through several use cases. The originality of the work stands on the processing approach, applied to data collected through new measurement process (e.g. Bluetooth, floating car data, connected vehicles). Then, the performance of our primary approach is compared to other learning-based methods. We propose an adaptation of kernel-based methods for the global prediction framework. The obtained results show that global approaches perform as well as usual approaches. The spatial and temporal specificities of the methods are highlighted according to the prediction accuracy. To improve the forecasting accuracy and reduce the computation time, we propose an identification and selection method targeting critical links. The results demonstrate that the use of a restricted subset of links is sufficient to ensure acceptable performances during validation tests. Finally, the prediction framework resilience is evaluated with respect to non-recurrent events as incidents or adverse weather conditions affecting the nominal network operations. The results highlight the impact of these non-recurrent conditions on real-time forecasting of short-term network dynamics. This enables the design of a further operational and resilient prediction framework. This perspective of forecasting matches the current applications relying on embedded systems and addressing the traffic network supervisor’s expectations.
496

Intervenções para melhora do sucesso reprodutivo em mulheres com falhas recorrentes de implantação submetidas à reprodução assistida: revisão sistematizada e metanálise / Interventions for improving reproductive outcomes in women with recurrent implantation failure undergoing assisted reproductive techniques: Systematic review and metanalysis

Miyague, Danielle Medeiros Teixeira 18 January 2019 (has links)
Justificativa: Falhas recorrentes de implantação (FRI) são uma fonte de grande frustração para pacientes e especialistas que, frequentemente buscam intervenções com o objetivo de atingir resultados favoráveis. A prevalência exata dessa condição é de difícil estimativa, uma vez que existem diversas definições para caracterizá-la. Diversas intervenções que visam a melhora dos resultados reprodutivos dessas pacientes já foram propostas. Entretanto, nenhuma revisão sistematizada abordou, simultaneamente, todas as potenciais estratégias para esse grupo de mulheres. Dessa forma, a eficácia e a segurança dessas intervenções não são bem definidas. Devido ao alto número de intervenções descritas para esse fim, julgamos que uma metanálise que as contemple de forma abrangente é importante para casais, especialistas e pesquisadores do assunto. Objetivos: Avaliar a eficácia e segurança das intervenções que visam a melhora do resultado reprodutivo das pacientes com FRI submetidas a um novo tratamento de reprodução assistida. Métodos de busca: As buscas por estudos randomizados e controlados, publicados e em andamento, foram realizadas nas principais bases de dados eletrônicas. Adicionalmente, as listas de referências de estudos incluídos e revisões semelhantes foram avaliadas pelos autores. A última busca eletrônica foi realizada em fevereiro de 2018. Critérios de Elegibilidade: Foram considerados elegíveis apenas os estudos verdadeiramente randomizados que comparassem quaisquer intervenções destinadas a esse grupo depacientes. No presente estudo, consideramos como FRI a história de duas ou mais falhas prévias. Extração e análise de dados: Dois autores realizaram, individualmente, a seleção de estudos, extração de dados e análise do risco de viés. Discordâncias foram resolvidas em consulta a um terceiro autor. Os pesquisadores de estudos potencialmente elegíveis foram contatados sempre que necessário para obtenção de informações adicionais. Resultados: Foram identificados 2794 registros; desses, 62 estudos foram incluídos, representando uma população de 9308 pacientes, submetidas a 26 intervenções diferentes. Informações sobre 24 intervenções e 8461 pacientes foram submetidas à análise quantitativa. Não há evidências de alta ou moderada qualidade de que alguma dessas intervenções seja realmente eficaz para a melhora dos resultados reprodutivos de pacientes com FRI. As seguintes intervenções se mostraram benéficas: assisted hatching, injúria endometrial, histeroscopia, uso de FSH urinário + recombinante para estimulação endometrial e administração intrauterina de hCG. Porém as evidências são de baixa qualidade, o que nos traz incerteza em relação aos seus reais efeitos. Todas as outras intervenções identificadas não permitiram nenhuma outra conclusão adicional, uma vez que as evidências foram avaliadas como de muito baixa qualidade ou não foram encontrados estudos randomizados que as tivessem avaliado. Conclusões: Evidências de ensaios clínicos randomizados não sustentam o uso de nenhuma intervenção para a melhora dos resultados reprodutivos de pacientes com FRI. Todos os achados foram julgados como de baixa ou muito baixa qualidade, o que nos traz incerteza quanto aos seus reais efeitos na prática clínica. Deve-se estar ciente de que o emprego de tais intervenções impõe despesas e riscos adicionais para as pacientes. Além disso, a falta de critérios universalmente aceitos para odiagnóstico de falha recorrente de implantação é uma importante limitação para o avanço do conhecimento sobre essa condição / Background: Recurrent implantation failure (RIF) is a source of deep frustration to couples and clinicians, who often look for interventions to improve the reproductive outcomes. Its exact prevalence is difficult to determine because there are several definitions used to describe the condition. Several interventions aiming to improve reproductive outcomes for such patients have been studied. However, there are no systematic reviews that focus on all potential interventions for improving reproductive outcomes in women with RIF undergoing assisted reproduction techniques. The efficacy and safety of these interventions are not clear. Because of the large number of potential interventions for this condition, it would be very difficult to be aware of the current evidence for all of them. We believe this systematic review is important for subfertile couples, clinicians and researchers. Objectives: To assess the efficacy and safety of interventions designed to improve reproductive outcomes in women with RIF undergoing ART. Search methods: We searched for randomised controlled trials (RCT) in electronic databases (Cochrane Gynaecology and Fertility Group (CGF), The Cochrane Central Register of Controlled Trials, MEDLINE Ovid, EMBASE Ovid, PsycINFO, PsycINFO Ovid, CINAHL, LILACS), trials registers (ClinicalTrials.gov, ISRCTN registry, The WHO International Clinical Trials Registry Platform, World Health Organization International Clinical Trials Registry Platform) and grey literature (OpenGrey); in addition, we handsearched the reference lists of included studies and similar reviews. We performed the last electronic search on 22 Feb 2018.Selection criteria: We considered eligible only truly randomised controlled trials comparing any intervention designed to improve outcomes in women with repeat implantation failure (RIF) compared to other intervention, placebo or no treatment. For study selection, we defined RIF as two or more previous failures Data collection and analysis: Two authors independently performed study selection, data extraction, and assessment of the risk of bias. Any disagreements were solved by consulting a third review author. Study\'s authors were contacted whenever needed to solve any queries. Results: the search retrieved 2794 records; from those, sixty-two studies were included, comprising 9308 participants, submitted to 26 different interventions. Data from 24 interventions and 8461 participants were pooled for quantitative analysis. We found no high or even moderate quality evidence that any of the tested interventions are really effective to improve reproductive outcomes of women with RIF undergoing a new IVF treatment. We observed low-quality evidence of benefit for women with RIF with the following interventions: assisted hatching, endometrial Injury, hysteroscopy, the use of human + recombinant FSH for ovarian stimulation and intrauterine hCG administration. All the other listed interventions did not allow any further conclusion: either very low-quality evidence or no evidence from RCTs. Conclusions: Evidence from RCTs does not support the use of any specific intervention for improving reproductive outcomes in women with RIF. All evidences were deemed of low to very low quality, which makes us uncertain of their real effectiveness on clinical practice. One should be aware that the employment of such interventions imposes additional expenses and risks. Additionally, the lack of universally accepted criteria for recurrent implantation failure is an important limitation for the advance of knowledge regarding this condition.More studies are needed to evaluate their real effect. Maybe even more importantly is to create universally accepted criteria for defining implantation failure; only them one will be able to test interventions for this specific group
497

A hermenêutica filosófica como possibilidade de controle da estandardização do direito: uma solução possível (salvamento) para as súmulas (comuns e vinculantes), repercussão geral e recursos repetitivos

Sausen, Dalton 07 July 2011 (has links)
Submitted by Mariana Dornelles Vargas (marianadv) on 2015-04-14T13:36:39Z No. of bitstreams: 1 hermeneutica_filosofica.pdf: 886897 bytes, checksum: 60f224d81e101abbedf2d450f59badb6 (MD5) / Made available in DSpace on 2015-04-14T13:36:39Z (GMT). No. of bitstreams: 1 hermeneutica_filosofica.pdf: 886897 bytes, checksum: 60f224d81e101abbedf2d450f59badb6 (MD5) Previous issue date: 2011-07-07 / Nenhuma / O presente estudo analisa as condições de possibilidade da hermenêutica filosófica para o controle da estandardização do direito e uma solução possível para as súmulas (comuns e vinculantes), repercussão geral e recursos repetitivos. Para tanto, investiga, num primeiro momento, o próprio constituir da estandardização do direito, sendo apontadas, nesse sentido, evidências, contingências e sintomas desse fenômeno, que tem o seu desvelar consubstanciado no precedente como ideal de um mundo jurídico homogeneizado. Em seguida, no segundo capítulo, aponta constatações e superações que se fazem necessárias em face do condicionamento discursivo decorrente dos significantes. Nesse aspecto, promove análise das súmulas, repercussão geral e recursos repetitivos, com o escopo de identificar para que e a quem servem esses mecanismos, e, ainda, se são eles elementos de estandardização e bloqueio de acesso à justiça, ou soluções razoáveis/possíveis para desafogar o sistema jurídico brasileiro, bem como analisa o controle social exercido pelo STF e STJ sob a perspectiva do componente ideológico dos significantes. Desata, também, reflexão acerca da necessidade da superação do mito do dado como condição de possibilidade para a (re)introdução da faticidade no mundo jurídico, bem como promove investigação em relação à primazia do discurso do Outro no sentido comum teórico, sua correlação com o paradigma vigente, sua gênese e, ainda, destaca o que é preciso mudar em face desse fenômeno. Na última parte do trabalho, a partir da justificação do porquê da adoção da hermenêutica filosófica, da explicitação do papel desvelador da fenomenologia hermenêutica e da importância da salvaguarda da pré-compreensão, tradição, coerência e integridade, sugere, como condição de possibilidade para o controle da estandardização do direito e o resgate hermenêutico das súmulas, repercussão geral e recursos repetitivos, a aplicação da teoria construída por Lenio Luiz Streck, que tem como pressupostos o mínimo é e o grau de objetivação abrangente. / This study examines the conditions of the philosophical hermeneutic possibility for the control of the standardization of Law and a possible solution to the summaries (common and binding), general repercussion and recurrent appeal. For such, it investigates, firstly, the very form of standardization of Law, pointing out in that sense, evidences, contingencies and symptoms of this phenomenon, which has its uncovering, consubstantiate in the previous ideal of a homogenized legal world. Following, the second chapter points to findings and conclusions that are necessary in the face of the discursive conditioning resulting from the significants. In this respect, it promotes the analysis of summaries, general repercussion and recurrent appeal with the aim to identify to what and to whom those mechanisms serve, and if they are elements of standardization and prevention of access to justice, or reasonable /possible solutions to help the Brazilian legal system to flow more smoothly, it analyzes the social control exercised by the STF and STJ from the perspective of the ideological component of the significants. It also unties a reflection on the necessity of overcoming the myth of the given as a condition of possibility for the (re) introduction of the instance in the legal world, and it promotes an investigation in relation to the primacy of the discourse of the Other in the theorist common sense, its correlation with the current paradigm, its genesis, and it also highlights the need for change in the face of this phenomenon. In the final section of the work, from the justification of reason for the adoption of philosophical hermeneutics, the explicit role of the uncovering of the hermeneutic phenomenology and the importance of safeguarding the pre-understanding, tradition, consistency and integrity, it is suggested, as a condition of possibility for the control and standardization of the Law and the of hermeneutical redemption of the summaries, general repercussion and recurrent appeal, the application of the theory built by Lenio Luiz Streck, whose assumptions is minimum is and degree of objectification comprehensive.
498

Immunogenetic regulation of Natural Killer cell function in pregnancy

Gaynor, Louise Michelle January 2017 (has links)
Uterine NK (uNK) cells are a distinct subset of NK cells in the decidua of humans and rodents during pregnancy, which are essential for remodelling of the spiral arteries supplying the feto-placental unit. Similarly to peripheral NK cells, uNK cells express Natural Killer receptors (NKRs) that engage MHC class I molecules. Evidence from human genetic association studies suggests that, in the presence of allogeneic cognate paternal MHC class I ligands, inhibitory uterine NKRs are associated with disorders of pregnancy arising from impaired decidual vascular remodelling. Conversely, enhancement of human uNK cell activity through activating NKRs is associated with high birth weight. Evidence from mouse models corroborates that uNK cell activity is modulated by interactions between NKRs and MHC class I, but has largely focussed on the effect of paternal MHC. In this study, the contribution of maternal immunogenetic regulation of NK cell function to reproductive outcome was assessed independently of parental MHC disparity in mice. To evaluate the role of NKR genes in isolation, I used congenic B6.BALB-TC1 (TC1) mice that differ from C57BL/6 (B6) mice only within the region of chromosome six encoding NKRs that recognise MHC class I. Absence of a major inhibitory NKR for self-MHC, Ly49I, in TC1 mice causes a compensatory shift in the NKR repertoire expressed and preserves a majority subpopulation of educated NK cells. B6 and TC1 splenic and uterine NK cells are similarly functionally reactive and mature, and no significant differences could be detected in spiral arterial remodelling or fetal growth between these strains in MHC-syngeneic matings. This supports data from human immunogenetic studies showing that maternal uterine NKRs are not associated with differences in pregnancy outcome in the absence of novel paternal MHC class I ligands, and highlights the importance of maternal and paternal co-regulation of uNK cell activity during pregnancy. No mouse models of uNK cell activation are currently available with which to corroborate human immunogenetic associations between activating uterine NKRs and high birth weight. Male m157-transgenic (m157-Tg) mice, which ubiquitously express viral m157 glycoprotein ligands for the activating NKR Ly49H, were mated with B6 females. Exclusive expression of m157 glycoprotein by trophoblast improved placental efficiency, but did not enhance fetal growth. Some fertility clinics surmise that uNK cell activation initiates the pathogenesis of spontaneous abortion. It has been suggested that this may occur due to reduced expression by human uNK cells of miR-483-3p, which stimulates endogenous insulin-like growth factor (IGF)-1 production and uNK cell cytotoxicity in vitro. It is demonstrated here that neither miR-483-3p nor IGF-1 regulate murine NK cell development, maturation or function. No discernible reproductive phenotype is evident in miR-483 deficient females. It can be inferred that post-transcriptional control by miR-483 is not biologically relevant to murine NK cell function. Although m157-Tg mice may provide an interesting model to further study uNK cell-mediated placental adaptations, it remains important to identify a murine model of enhanced uNK cell function to corroborate human immunogenetic associations with high birth weight and to challenge the supposition that uNK cell activation is harmful to pregnancy.
499

Redes Neurais Aplicadas à InferÃncia dos Sinais de Controle de Dosagem de Coagulantes em uma ETA por FiltraÃÃo RÃpida / Artificial Neural Networks applied to the inference of dosage control signals of coagulants in a water treatment plant by direct filtrationâ,

Leonaldo da Silva Gomes 28 February 2012 (has links)
Considerando a importÃncia do controle da coagulaÃÃo quÃmica para o processo de tratamento de Ãgua por filtraÃÃo rÃpida, esta dissertaÃÃo propÃe a aplicaÃÃo de redes neurais artificiais para inferÃncia dos sinais de controle de dosagem de coagulantes principal e auxiliar, no processo de coagulaÃÃo quÃmica em uma estaÃÃo de tratamento de Ãgua por filtraÃÃo rÃpida. Para tanto, foi feito uma anÃlise comparativa da aplicaÃÃo de modelos baseados em redes neurais do tipo: alimentada adiante focada atrasada no tempo (FTLFN); alimentada adiante atrasada no tempo distribuÃda (DTLFN); recorrente de Elman (ERN) e auto-regressiva nÃo-linear com entradas exÃgenas (NARX). Da anÃlise comparativa, o modelo baseado em redes NARX apresentou melhores resultados, evidenciando o potencial do modelo para uso em casos reais, o que contribuirà para a viabilizaÃÃo de projetos desta natureza em estaÃÃes de tratamento de Ãgua de pequeno porte. / Considering the importance of the chemical coagulation control for the water treatment by direct filtration, this work proposes the application of artificial neural networks for inference of dosage control signals of principal and auxiliary coagulant, in the chemical coagulation process in a water treatment plant by direct filtration. To that end, was made a comparative analysis of the application of models based on neural networks, such as: Focused Time Lagged Feedforward Network (FTLFN); Distributed Time Lagged Feedforward Network (DTLFN); Elman Recurrent Network (ERN) and Non-linear Autoregressive with exogenous inputs (NARX). From the comparative analysis, the model based on NARX networks showed better results, demonstrating the potential of the model for use in real cases, which will contribute to the viability of projects of this nature in small size water treatment plants.
500

Métodos neuronais para a solução da equação algébrica de Riccati e o LQR / Neural methods for the solution of Equation Of algebraic Riccati and LQR

SILVA, Fabio Nogueira da 20 June 2008 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-08-14T18:28:45Z No. of bitstreams: 1 FabioSilva.pdf: 1098466 bytes, checksum: a72dcced91748fe6c54f3cab86c19849 (MD5) / Made available in DSpace on 2017-08-14T18:28:45Z (GMT). No. of bitstreams: 1 FabioSilva.pdf: 1098466 bytes, checksum: a72dcced91748fe6c54f3cab86c19849 (MD5) Previous issue date: 2008-06-20 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / We present in this work the results about two neural networks methods to solve the algebraic Riccati(ARE), what are used in many applications, mainly in the Linear Quadratic Regulator (LQR), H2 and H1 controls. First is showed the real symmetric form of the ARE and two methods based on neural computation. One feedforward neural network (FNN), that de¯nes an error as function of the ARE and a recurrent neural network (RNN), which converts a constrain optimization problem, restricted to the state space model, into an unconstrained convex optimization problem de¯ning an energy as function of the ARE and Cholesky factor. A proposal to chose the learning parameters of the RNN used to solve the ARE, by making a surface of the parameters variations, thus we can tune the neural network for a better performance. Computational experiments related with the plant matrices perturbations of the tested systems in order to perform an analysis of the behavior of the presented methodologies, that are based on homotopies methods, where we chose a good initial condition and compare the results to the Schur method. Two 6th order systems were used, a Doubly Fed Induction Generator(DFIG) and an aircraft plant. The results showed the RNN a good alternative compared with the FNN and Schur methods. / Apresenta-se nesta dissertação os resultados a respeito de dois métodos neuronais para a resolução da equação algébrica de Riccati(EAR), que tem varias aplicações, sendo principalmente usada pelos Regulador Linear Quadrático(LQR), controle H2 e controle H1. É apresentado a EAR real e simétrica e dois métodos baseados em uma rede neuronal direta (RND) que tem a função de erro associada a EAR e uma rede neuronal recorrente (RNR) que converte um problema de otimização restrita ao modelo de espaço de estados em outro de otimização convexa em função da EAR e do fator de Cholesky de modo a usufruir das propriedades de convexidade e condições de otimalidade. Uma proposta para a escolha dos parâmetros da RNR usada para solucionar a EAR por meio da geração de superfícies com a variação paramétrica da RNR, podendo assim melhor sintonizar a rede neuronal para um melhor desempenho. Experimentos computacionais relacionados a perturbações nos sistemas foram realizados para analisar o comportamento das metodologias apresentadas, tendo como base o princípio dos métodos homotópicos, com uma boa condição inicial, a partir de uma ponto de operação estável e comparamos os resultados com o método de Schur. Foram usadas as plantas de dois sistemas: uma representando a dinâmica de uma aeronave e outra de um motor de indução eólico duplamente alimentado(DFIG), ambos sistemas de 6a ordem. Os resultados mostram que a RNR é uma boa alternativa se comparado com a RND e com o método de Schur.

Page generated in 0.0989 seconds