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Delgado, Christophe Sidney. "L'Amélogénine, protéine majeure de l'émail dentaire : origine, analyses évolutive et phylogénétique chez les Amniotes et recherche de son expression lors de la formation des dents de Chalcides viridanus (Squamate,Scincidé)." Paris 7, 2002. http://www.theses.fr/2002PA077066.
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Long, David. "Met Office upper stratospheric and mesospheric analaysis : validation and improvement of gravity wave drag scheme." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3104.
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The global analysis fields of the Met Office stratospheric assimilated data set have been investigated. Systematic biases for select years were identified through val- idation with independent satellite observations. Particular attention was given to analyses from January 2005 to October 2009 produced from a 50 level (L50) configuration of the UM with model lid at ∼0.1 hPa, and the impact on analyses fields from November 2009 to September 2010 when the middle atmospheric configuration of the UM was extended to ∼0.01 hPa using 70 levels (L70). Validation results from both the L50 and L70 analyses show that largest tem- perature biases occur at polar latitudes approaching the model lid in the meso- sphere, exhibiting a clear seasonal cycle. Here cold biases in the winter season of the L50 analyses and warm biases in the summer season of the L70 analyses would strongly suggest that the mean meridional circulation in the mesosphere is underestimated, and that small scale gravity wave forcing supplied by the op- erational Ultra Simple Spectral Parameterisation (USSP) scheme is insufficient. Based on the above validation results numerous experiments were conducted to investigate the temperature response in the mesosphere to increased gravity wave forcing. Such experiments concentrated on tuning the energy scale factor (β) in the USSP scheme and the application of a momentum conserving ”opaque” lid. Furthermore, the impact of developing the USSP scheme to include direct heating from gravity wave induced turbulent dissipation was also investigated. Maximum temperature responses in the summer polar upper mesosphere of ∼22 K were found when increasing the standard value of β=0.1 to β=0.14 combined with the application of an opaque lid. Magnitudes of direct heating rates due to gravity wave turbulent dissipation diagnosed via the USSP scheme were found to be consistent with previous estimates. However applying such heating would most likely have a negative impact on the L70 analyses, which already display warm biases in the upper mesosphere, strongly suggesting that additional phys- ical processes such as eddy diffusion must also be accounted for when applying direct heating from gravity wave breaking.
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Bello, Nicolas. "Effets d'un vieillissement longue durée sur deux alliages d'aluminium de la série 2000." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30301/document.
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Ces travaux de thèse réalisés entre l'IRT Saint Exupéry et le CEMES, Université de Toulouse, CNRS ont pour objet l'étude d’alliages de la série 2000 pour des utilisations à des températures intermédiaires, de l'ordre de 200°C. La possibilité d'utiliser ces matériaux à cette température permettrait aux industriels du secteur aéronautique de réduire les coûts de production d'une part, et de diminuer les coûts d'exploitation des aéronefs ainsi plus légers d'autre part. Afin de répondre à cette problématique industrielle, deux nuances commerciales ont été considérées : le 2219-T851 et le 2050-T84. Ces nuances, déjà utilisées dans l'industrie aéronautique, ont été caractérisées à différentes échelles d'observation tout au long d'un vieillissement isotherme à 200°C allant jusqu’à 10000 h. Des observations effectuées à l'aide de divers microscopes optiques et électroniques et couplées à des essais mécaniques macroscopiques ont permis de déterminer l'évolution de ces nuances vieillies dans de telles conditions. Les résultats de cette étude montrent une importante stabilité thermodynamique des précipités nanométriques θ'-Al2Cu. Ces précipités constituent la microstructure fine de la nuance 2219-T851 à réception et apparaissent au cours du vieillissement au sein de la nuance 2050-T84 au détriment des précipités T1-Al2CuLi pourtant à l'origine des meilleures performances mécaniques avant vieillissement. Les évolutions microstructurales sont mises en lien avec les propriétés mécaniques en traction. Ces résultats montrent un intérêt industriel pour la nuance 2219-T851 dont la stabilité des propriétés a été montrée dès 1000h de vieillissementThe main objective of this work which has been conducted between the IRT Saint Exupéry and the CEMES, Université de Toulouse, CNRS laboratory is to reduce production and exploitation costs of aircraft primary structures by evaluating the potential increase of operating temperatures of aluminum alloys. To do so, two already fit-to-fly Al-Cu alloys have been selected and studied: the 2219-T851 and the 2050-T84. These alloys have been characterized throughout ageing treatments up to 10,000h at 200°C with electronic and optical microscopies in order to evaluate the microstructural changes. Standardized mechanical tests have also been conducted to follow the effects of such ageing on the alloys’ properties. The results have shown the stability of the mechanical properties and the microstructure of the 2219-T851 from 1,000h to 10,000h of ageing. This is attributed to the nano-precipitation of θ'-Al2 Cu, stable during the ageing treatment. Moreover, those precipitates tend to form during the ageing of the 2050-T84 by replacing the well known T1-Al2CuLi phase, unstable during medium range temperature ageing. During this thesis, special attention has been paid on the link between the mechanical properties and the fine scale microstructures of both alloys
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Breed, Catharina Adriana. "Die herskryf van die roman Die swye van Mario Salviati van Etienne van Heerden as 'n draaiboek, met spesifieke fokus op identiteit, hibriditeit en liminaliteit / C.A. Breed." Thesis, North-West University, 2007. http://hdl.handle.net/10394/1671.
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Salmi-Boukhari, Btissam. "Intégration de données pour la qualité de la viande chez le porc : Méta-analyse et analyse multidimensionnelle." Thesis, Paris, AgroParisTech, 2011. http://www.theses.fr/2011AGPT0060/document.
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La qualité de la viande englobe des critères d'importance différente suivant l'espèce animale considérée. Chez le porc, la qualité de la viande a un impact économique important et de nombreux travaux ont pu montrer que les interactions entre le type génétique (particulièrement les gènes halothane et Rendement Napole), les conditions d'élevage et les conditions d'abattage des animaux déterminent la qualité de la viande de porc. L'Europe, longtemps leader du marché mondial des produits de la viande de porc, se trouve aujourd'hui confronté à la concurrence d'autres pays, notamment le Brésil, les Etats-unis et la Chine. Ce projet de thèse s'inscrit dans le cadre d'un projet européen multidisciplinaire portant sur l'amélioration de la qualité de la viande de porc et des produits dérivés pour le consommateur. Un des modules est dédié à l'intégration des connaissances passées et celles à venir afin de construire des modèles de prédiction des qualités technologiques et sensorielles de la viande de porc à partir des données se rapportant à l'animal, ainsi qu'aux conditions d'élevage et de pré-abattage. L'objectif de la thèse est d'intégrer l'ensemble des données bibliographiques et expérimentales relatives aux principaux facteurs influençant la qualité de viande dans le cadre d'une méta-analyse, qui est une démarche statistique combinant les résultats d'une série d'études indépendantes sur un problème donné. Les résultats obtenus ont permis de préciser l'effet du gène halothane, des temps de jeûne, de transport et de repos à l'abattoir sur les principaux paramètres d'évaluation de la qualité technologique de la viande de porc. En effet, nos résultats ont pu confirmer l'effet significatif du gène halothane sur l'ensemble des paramètres de qualité étudiés. Cependant, l'effet significatif du gène halothane a été associé à celui de la race uniquement pour expliquer les variations des paramètres suivants : L* (la réflectance), b* (indice de jaune) et les pertes d'exsudat (DL). La méta-régression a permis de mettre en évidence l'effet du poids à l'abattage sur les différences de pH ultime (pHu) entre les génotypes homozygotes NN et nn. Parmi les facteurs de pré-abattage analysés, nos résultats indiquent que le temps de jeûne affecte le pHu et le DL mesurés au niveau du muscle longissimus, alors que le temps de repos à l'abattoir affecte le pHu du muscle semimembranosus. Le transport et l'interaction transport x temps de jeûne n'avaient d'effet significatif que sur les variations de DL. L'effet significatif de l'apport en vitamine E sur le processus d'oxydation des lipides pendant la conservation de la viande, et par conséquent, sur la qualité technologique de la viande a pu être démontré en utilisant un modèle de régressionméta-analytique non linéaire. D'un point de vue statistique, la comparaison des méthodes statistiques de méta-analyse par approche bayésienne et fréquentiste a permis de mettre en évidence l'avantage de la première quant à l'obtention de résultats plus probants lorsqu'il s'agit de méta-analyse sur un nombre de données relativement limité. Parallèlement à l'approche méta-analytique, une étude exploratoire par analyse multivariée a été réalisée afin d'identifier les corrélations qui existent entre un très grand nombre de variables structurées en groupes distincts. Nos résultats ont montré que les variables discriminant les cinq classes de race (Large White et Basque) x système d'élevage (conventionnel, alternatif et extensif) étaient les mêmes que celles qui discriminaient les individus entre eux, en l'occurrence les variables transcriptomiques, chimiques et technologiques. Le groupe composé des variables relatives à la réactivité à l'abattage discriminaient principalement les systèmes d'élevage, en particulier la classe des porcs basques élevés dans le système extensifMeat quality includes criteria of different importance depending on the animal species. Meat quality is a significant economic factor in pork production, and numerous publications have shown that it is strongly influenced by the interaction between genetic type (especially the halothane gene (Hal) and Napole yield gene (RN)), breeding conditions, and pre-slaughter and slaughter conditions of animals. The European Union, longtime leader of the globalmarket of pork and pork products, now faces increasing competition from other countries,including Brazil, the United States and China. This thesis project is part of a multidisciplinary European project on improving the quality of pork and pork products for the consumer. One of the modules of this project is dedicated to the integration of existing and upcoming data to produce a model for predicting technological and sensory pork quality, based on animal,production, and slaughter information. The objective of this thesis is to synthesize existing knowledge derived from bibliographic and experimental data relating to the main factors influencing meat quality within a meta-analysis, which is a statistical approach combining the results of a series of independent studies on a given problem. The results of this work have confirmed the effect of the halothane gene, as well as fasting, transport and lairage times on most of the analyzed parameters of technological pork meat quality. Indeed, our meta-analysis confirmed the significant effect of the halothane gene on all the analyzed meat quality attributes. However, the halothane gene effect was associated with the breed effect only for the following variables: L*-value (reflectance), b*-value (yellowness) and DL (drip loss). Slaughter weight contributed significantly only to the explanation of differences in ultimate pH between homozygous genotypes: NN and nn. Regarding the preslaughter conditions, the results of our meta-analysis showed that fasting time had a significant effect on pHu and DL measured in longissimus muscle. While, lairage affected only the pHu in semimembranosusmuscle. Interestingly, we found that DL was the lonely attribute significantly affected by transport time and its interaction with fasting time. The significant effect of the vitamin E supplementation on lipid oxidation process in pork and, therefore, affect the technological meat quality, was demonstrated by using a non linear meta-analytic regression model. Statistically, the comparison between the Bayesian and frequentist meta-analytic approaches has highlighted the ability of the hierarchical Bayesian model to reduce uncertainty in parameter estimates, especially when the number of studies included in the meta-analysis is relatively limited. In addition to the meta-analytic approach, an exploratory study by multivariate analyses was performed to identify the correlations among a large number of variables structured into separate groups. Our results showed that the variables which discriminated the five classes of breed (Large White and Basque pigs) x rearing system (conventional, alternative and extensive) were the same as those discriminating individuals. Indeed, a first group composed of transcriptomic, chemical and technological variables discriminated breeds. Slaughter reactivity variables discriminated rearing systems, especially the Basque pigs reared in the extensive system
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Trefan, Laszlo. "Development of empirical models for pork quality." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/5761.
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Pork quality is an important issue for the whole meat chain, from producers, abattoirs, retailers through to costumers and is affected by a web of multi-factorial actions that occur throughout the pork production chain. A vast amount of information is available on how these diverse factors influence different pork quality traits. However, results derived from individual studies often vary and are in some cases even contradictory due to different experimental designs or different pork quality assessment techniques or protocols. Also, individual influencing factors are often studied in isolation, ignoring interacting effects. A suitable method is therefore required to account for a range of interacting factors, to combine the results from different experiments and to derive generic response-laws. The aim of this thesis was to use meta-analyses to produce quantitative, predictive models that describe how diverse factors affect pork quality over a range of experimental conditions.
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Rustenbach, Stephan Jeff. "Metaanalyse : eine anwendungsorientierte Einführung /." Bern ; Seattle : Hans Huber, 2003. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009805594&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Raynaut, William. "Perspectives de méta-analyse pour un environnement d'aide à la simulation et prédiction." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30005/document.
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L'émergence du phénomène Big Data a créé un besoin grandissant en analyse de données, mais, bien souvent, cette analyse est conduite par des experts de différents domaines ayant peu d'expérience en science des données. On s'intéresse donc à ce besoin d'assistance à l'analyse de données, qui commence tout juste à recevoir une certaine attention des communautés scientifiques, donnant naissance au domaine de la méta-analyse. Les premières approches du sujet se révélant souvent similaires et peu abouties, on tente en particulier de permettre de nouvelles approches de méta-analyse pour adresser ce problème d'assistance à l'analyse de données. Pour ce faire, une première étape cruciale est de déterminer ce qu'est une méta-analyse performante, aucun standard n'ayant encore été établi dans ce domaine relativement neuf. On propose ainsi un cadre générique d'évaluation de méta-analyse, permettant de comparer et caractériser finement diverses techniques de méta- analyse. Ensuite, afin d'ouvrir de nouvelles voies, on s'intéresse à un verrou majeur de la méta-analyse : la caractérisation de jeu de données. On propose et évalue alors une caractérisation par dissimilarité faisant usage de toute l'information disponible pour autoriser de nouvelles approches de méta-analyse. L'utilisation de cette caractérisation par dissimilarité permettant de recommander facilement des processus d'analyse de données complets, on décrit enfin les nouvelles approches de méta-analyses rendues possibles, ainsi que les processus afférents d'assistance à l'analyse de donnéesThe emergence of the big data phenomenon has led to increasing demands in data analysis, which most often are conducted by other domains experts with little experience in data science. We then consider this important demand in intelligent assistance to data analysis, which receives an increasing attention from the scientific community. The first takes on the subject often possessing similar shortcomings, we propose to address it through new processes of meta-analysis. No evaluation standard having yet been set in this relatively new domain, we first propose a meta-analysis evaluation framework that will allow us to test and compare the developed methods. In order to open new approaches of meta-analysis, we then consider one of its recurring issue: dataset characterization. We then propose and evaluate such a characterization, consisting in a dissimilarity between datasets making use of a precise topological description to compare them. This dissimilarity allows a new meta-analysis approach producing recommendations of complete data analysis processes, which we then evaluate on a proof of concept. We thus detail the proposed methods of meta-analysis, and the associated process of assistance to data analysis
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Rangmark, Ulrika, and Konstantin Sidorenko. "Genus & Mat : en analys av "Mat" och "Vad blir det för mat?" utifrån ett genus- och dramaturgiskt perspektiv." Thesis, Södertörns högskola, Institutionen för samhällsvetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-24696.
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Syftet med denna studie var att undersöka samspelet mellan genus och matlagning samt hur deras roller utspelas i matlagningsprogrammen. Ett urval av tidigare forskning som behandlar vårt specifika ämne samt hur vår studie särskiljer sig från dem återfinns under kapitel två. Med hjälp av de två metoderna kvantitativ och kvalitativ innehållsanalys analyserades innehållet i utvalda avsnitt ur ”Mat” och ”Vad blir det för mat?”. Urvalet av de avsnitt som studerade skedde med ett systematiskt urval. Med Erving Goffmans teori och utvalda nyckelbegrepp skapades ett kodschema som vi sedan applicerade i studiens analysdel. Vi har på ett detaljerat sätt studerat programmen för att se vem som gör vad samt på vilket sätt det presenteras med genusperspektivet i åtanke. Det vi kom fram till var att genus var en väsentlig faktor till de främsta skillnaderna i programmen som i sin tur påverkade aktörernas roller.The purpose of this study was to examine the interaction between gender and cooking, and how their roles unfolding in cooking programs. A selection of previous research that addresses our specific topic and how our study differs from those found in chapter two. Using the two methods quantitative and qualitative content analysis analyzed the contents of selected passages from "Mat" and "Vad blir det för mat? '. The selection of the sections studied were made with a systematic sample. With Erving Goffman's theory and selected key concepts created a coding scheme which we then applied in the study analysis section. We have a detailed manner studied programs to see who is doing what and how it is presented with a gender perspective in mind. What we came up with was that gender was a significant factor for the primary differences in the programs, which in turn affected the actors' roles.
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Pierron, Olivier. "Interactions eau-fer-argilite : rôle des paramètres liquide/roche, fer/argilite, température sur la nature des phases minérales." Thesis, Nancy 1, 2011. http://www.theses.fr/2011NAN10146/document.
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Les interactions entre le fer métal et l'argilite du Callovo-Oxfordien choisie comme roche hôte pour le stockage des déchets radioactifs, a été étudiée expérimentalement. Le rôle des paramètres clés des transformations (rapports fer/argile, et liquide/roche) ont été étudiés à 90°C, et afin d'accélérer la cinétique des réactions à 150°C et 300°C. Les interstratifiés illite-smectite et les illites sont dissous et remplacés par de nouvelles phases argileuses. Les analyses au MET ont permis de déterminer des Fe-serpentines (phases à 7 Å, groupe de la berthiérine) à 90°C, des phases gonflantes de type smectite tri-octaédrique à 150°C, et des chlorites et des interstratifiés chlorite/smectite à 300°C. Quelle que soit la température, la transformation des feuillets illitiques (I et I/S) n'est pas complète et il reste toujours des feuillets à garniture interfoliaire sodi-calcique, interprétés comme des smectites résiduelles ou néoformées. En comparaison avec le système fer-smectite (bentonite), les différences portent sur la cinétique de réaction, beaucoup plus rapide dans le cas de l'argilite, et l'instabilité du quartz qui comme l'illite contribue à libérer le silicium nécessaire à la formation des silicates de fer. Les transformations observées trouvent des analogies avec les altérations hydrothermales et métasomatoses Fe-Mg des systèmes naturelsThe interactions between the iron metal and the argillite from the Callovo-Oxfordian formation chosen as host for the disposal of the radioactive wastes, was experimentally studied. The role of the key parameters of the transformations (iron / clay, and liquid / rock ratios) was studied at 90°C, and, to accelerate reaction kinetics, at 150°C and 300°C. Mixed layered illite-smectite and illites are dissolved and replaced by new clay phases. TEM analyses show that Fe-serpentines (7 Å phases, group of the berthierine) predominates in run products at 90°C, tri-octaedral Fe-rich smectites at 150°C, and chlorites and probably smectite chlorite mixed layered at 300°C. Whatever the temperature, the illite and I/S replacement is not complete and trun products are always accompanied by sodi-calcic residual and/ or newly formed smectites. In comparison with the iron-smectite (bentonite) system, the differences concern the reaction kinetics which are much faster in the case of the argillite, and the instability of the quartz which, as the illite, contributes to release the silicium necessary for the formation of iron silicates. The observed process find analogies with the hydrothermal changes described in natural hydrothermal alterations and Fe-Mg metasomatism
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Kamikura, Darren M. "Structurefunction analysis of the met receptor oncoprotein, Tpr-met." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37575.
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The Met protooncogene encodes a receptor tyrosine kinase that is deregulated by point mutation, and overexpression/amplification in a number of human tumours. The Met receptor is also oncogenically activated following genomic rearrangement which generates a cytoplasmic, constitutively activated fusion protein, Tpr-Met. In addition to autophosphorylation sites within the catalytic domain, the carboxy terminus of Tpr-Met/Met contains a single major site of autophosphorylation, tyrosine 489. This tyrosine residue represents a unique multisubstrate binding site, capable of binding numerous intracellular proteins, and is critical for the biological activities of both the Met receptor and Tpr-Met oncoprotein. Addition of the c-src myristoylation sequence to the amino terminus of the normally cytoplasmic Tpr-Met, localizes Tpr-Met to plasma membranes and enhances cellular transformation, in vitro invasion, and tumourigenicity. Furthermore, a membrane targetted Tpr-Met is localized to a similar subcellular compartment as the Met receptor, and alters the complement of signalling proteins required for efficient transformation. In this respect, a membrane localized Tpr-Met resembles oncogenic forms of the transmembrane Met receptor, and provides a model with which to study transformation by Met receptor oncoproteins. Significantly, membrane localization of Tpr-Met induces a phosphoinositide 3' kinase (PI3' K) dependent autocrine loop, involving the production of hyaluronic acid (HA), and post-translational modification of the cell surface receptor for HA, CD44. PI3'K activity and the HA/CD44 autocrine loop, are dependent on the multisubstrate binding site, tyrosine 489, and tyrosine residue 498, a residue with no previously described biochemical function. Although the exact mechanisms by which PI3'K regulates HA production are unclear, the induction of a HA/CD44 autocrine loop may represent a novel mechanism by which deregulated receptor tyrosine kinases increase their onco
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Kahloul, Senda. "Analyse structurale et fonctionnelle de la sous-unité SKP1 du complexe SCF (Skp1-Cullin-Fbox) chez le riz (Oryza sativa)." Thesis, Clermont-Ferrand 2, 2012. http://www.theses.fr/2012CLF22326/document.
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Chez les eucaryotes, la voie de protéolyse Ub/ protéasome 26S est responsable de la dégradation sélective de la plupart des protéines intracellulaires. Cette dégradation par le protéasome 26S est initiée par une polyubiquitination de la protéine réalisée grâce à l’action d’une cascade enzymatique impliquant 3 types d'enzymes nommées « ubiquitin-activating enzyme » (E1), « ubiquitin-conjugating enzyme » (E2) et « ubiquitin-protein ligase » (E3). Il existe différentes classes d’ubiquitines ligases (E3), parmi lesquelles la plus connue est le complexe SCF (Skp1-Cullin-F-box). La protéine SKP1 fixe à la fois la Culline et la F-box qui va reconnaitre spécifiquement la protéine cible. Contrairement aux protistes, les champignons et certains vertébrés qui possèdent un unique gène SKP1 fonctionnel, de nombreux animaux et espèces de plantes présentent plusieurs SKP1 homologues. Vingt et un et trente deux gènes SKP1 ont été décrits respectivement chez Arabidopsis thaliana et Oryza sativa. En dépit de l’importance du complexe SCF, chez le riz, peu de travaux décrivent les interactions entre les dizaines de protéines « SKP1-like » et les centaines de protéines F-box. Dans un premier temps, nous avons collecté et analysé les séquences de 288 gènes « SKP1-like » appartenant à 17 espèces, dont la mousse Physcomitrella patens, cinq monocotylédones et 11 eudicotylédones. Les analyses structurales et phylogénétiques de ces gènes indiquent qu’ils peuvent être divisés en différentes sous-familles. Nos analyses ont montré qu’OSK1 et OSK20 chez le riz constituent une classe de gènes SKP1 à intron unique conservé. Dans un deuxième temps, nous avons étudié le profil d’expression des gènes « SKP1-like » chez le riz. Notre investigation sur le nombre d’EST a montré que les gènes OSK1 et OSK20 sont les plus largement représentés dans les bases de données EST publiques. La méta-analyse de l’expression des gènes « SKP1-like » chez le riz, indique que les gènes OSK présentent des profils d'expression hétérogènes selon les tissus et les conditions physiologiques. Les résultats des intearctions protéine-protéine en double hybride ont révélé que les protéines OSK présentent différentes capacités d’interactions avec les protéines F-box. Cependant, OSK1 et OSK20 semblent interagir avec la plupart des protéines F-box testées. Les études de localisation subcellulaire ont indiqué que OSK1 et OSK20 sont des protéines nucléaires et cytosoliques. En se basant sur les divers résultats obtenus dans ce travail, nous pouvons suggérer que chez le riz, les gènes OSK1 et OSK20 sont fonctionnellement équivalents aux gènes ASK1 et ASK2 chez Arabidopsis thaliana. Nous pouvons également proposer les équivalents de ces gènes chez les autres espèces végétales dont le génome a été séquencéIn eukaryotes, the ubiquitin Ub/26S proteasome pathway is responsible for the selective degradation of most intracellular proteins. This cellular process is initiated by protein polyubiquitination mediated by a three-step cascade involving: an ubiquitin-activating enzyme (E1), an ubiquitin-conjugating enzyme (E2) and an ubiquitin-protein ligase (E3). The E3 ubiquitin ligases contain several classes, among which the best-known are Skp1-Cullin-F-box (SCF) complexes. The SKP1 protein binds both Cullin and F-box which recognizes specifically the target proteins. Whereas protists, fungi and some vertebrates have a single functional SKP1 gene, many animal and plant species possess multiple SKP1 homologues. Twenty one and thirty-two SKP1-related genes have been described respectively in the Arabidopsis and Oryza sativa genome. Despite the importance of the SCF complex, there have been a few reports of systematic surveys of interactions between the dozens of SKP1-like proteins and the hundreds of F-box proteins in rice. In a first step, we retrieved and analyzed 288 SKP1-like genes belonging to 17 species including the moss Physcomitrella patens, five monocots and 11 eudicots. Structural and phylogenetic analysis of rice OSK genes and other plant SKP1-like genes have indicated that the different members of the plant SKP1 can be split into different subfamily. Our analyses indicated that OSK1 and OSK20 belong to a class of SKP1 genes that contain one intron at a conserved position. In a second step, we studied expression profiles of the rice Skp1-like genes. Our EST survey indicated that OSK1 and OSK20 are the most widely represented genes in public EST databases. Meta-analysis of the expression of rice SKP1-like genes indicated that OSK genes exhibit an expression profile that was heterogeneous in terms of tissues, conditions and overall intensity. Yeast two-hybrid results revealed that OSK proteins display a differing ability to interact with F-box proteins. However, OSK1 and OSK20 seemed to interact with most F-box proteins tested. Subcellular localization studies indicated that OSK1 and OSK20 are nuclear and cytosolic proteins. Based on the results obtained in this study, we can suggest that rice OSK1 and OSK20 are likely to have similar functions as do the Arabidopsis ASK1 and ASK2 genes. Similarly, we suggest a list of functional equivalent in the other sequenced plant genomes
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Kamikura, Darren M. "Structure/function analysis of the Met receptor oncoprotein, Tpr-Met." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0019/NQ55343.pdf.
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Arndt, Stephanie, Gunnar Gaitzsch, Carsten Gnauck, Christoph Höhne, Anne-Karen Hüske, Thomas Kretzschmar, Ulrike Lange, Katrin Lehmann, and André Süss. "The Relation between Corporate Economic and Corporate Environmental Performance." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-38454.
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For almost 40 years researchers have been trying to identify the relationship between corporate environmental and corporate economic performance. Neither theoretical debate nor empirical studies investigating the relationship show conclusive results. Within a field research seminar at Technische Universität Dresden, nine students conducted a meta-analysis of 124 studies to assess different aspects of the relationship between corporate economic and corporate environmental performance. In the first part of our paper, we analyze and present the theoretical background based on a review of literature. In the second part, we test for empirical evidence. At first, the conceptual frameworks and measurement methods for corporate economic and corporate environmental performance are discussed. We also look at the impact of environmental performance on shareholder value. Thereafter, we examine the influence of time, industries and publication bias. In conclusion, our research indicates that the quality of journals merits further examination to improve results.
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Naudet, Florian. "Incidence de la procédure expérimentale sur l'évaluation de l'efficacité des pharmacothérapies antidépressives." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1B007.
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Les antidépresseurs sont les traitements pharmacologiques de choix de la dépression. Pourtant devant un nombre non négligeable d’études « négatives » et l’absence d’efficacité dans les dépressions peu sévères, la question de leur utilité reste controversée. Cette controverse présuppose que l’efficacité des antidépresseurs se mesure facilement. Pourtant, comme dans toute expérience, le dispositif expérimental peut influencer le résultat mis en évidence. L’objectif de cette thèse est justement d’explorer l’incidence de la procédure expérimentale sur l'effet mesuré des pharmacothérapies antidépressives. Est-ce que leur efficacité mesurée dans les études randomisées reflète leur effectivité (dans la « vraie vie ») ? Pour répondre à cette question, nous avons conduit une méta-analyse d’un large panel d’études de méthodologies très différentes. Une méta-régression a été réalisée pour modéliser la réponse au traitement en fonction des caractéristiques des études. Elle a permis de mettre en évidence 1/ une réponse supérieure dans les essais randomisés par rapport aux études observationnelles (possiblement plus représentatives de la « vraie vie »); 2/ une variation de la réponse en fonction de la durée de l’étude, du nombre de visites de suivi, de la population de patients inclus, du type d’analyse choisie, de la possibilité d’avoir un placebo et du design en aveugle. Une revue de la littérature apporte ensuite une perspective qualitative à la question posée. L’objectif était de décrire les dispositifs expérimentaux actuellement utilisés ou envisageables dans l’évaluation des antidépresseurs. La revue de la littérature 1/ a permis de préciser les limites des études actuelles en termes de validité interne (mesure des critères de jugement, attrition, levée de l’aveugle importance de la réponse placebo) et externe (difficultés majeures de généralisations des études); 2/ conduit à proposer une évaluation multimodale des antidépresseurs dans laquelle les études observationnelles auraient toute leur place. La question de la mesure est ensuite abordée à travers des simulations. Après avoir exploré l’impact du dispositif expérimental au niveau de l’essai en soi, le phénomène est analysé à un niveau plus global. Le choix a été fait d’un raisonnement par l’absurde, sur le terrain de la « comparative effectiveness ». L’objectif était de comparer les placebos d’antidépresseurs grâce à une méta-analyse en réseau. Ces comparaisons indirectes n’ont pas permis de mettre en évidence de différence entre placebos d’antidépresseurs. Un biais de publication a pu être mis en évidence et empêche de conclure formellement sur un résultat pourtant évident. Ce résultat ouvre une discussion sur le degré de confiance que l’on peut apporter à ce que l’on considère généralement comme des preuves scientifiques de l’effectivité de nos pratiques. Nos résultats impliquent un nouvel éclairage à la controverse sur les antidépresseurs en replaçant le débat sur le terrain épistémologiqueAntidepressant drugs have become the most prescribed and used pharmacological treatment for depressive disorders. Yet, their usefulness is still being debated in view of a significant number of “negative” studies and of their lack of efficacy in mild depressive disorders. This controversy presupposes that the efficacy of antidepressants can easily be measured. However, as in any experiment, the experimental method may influence the outcome. The aim of this thesis is precisely to explore the impact of the experimental procedures on the measured effect of antidepressant therapies. Also we ask the question of whether their efficacy measured in randomized trials reflects their “effectiveness” (in a “real life” setting)? To answer these questions, we performed a meta-analysis of a large number of studies with different methodologies. A meta-regression was performed to modelize the response to the treatment according to the studies’ characteristics. It highlighted 1/ a superior response in randomized trials compared to observational studies (possibly more representative of the “real life”); 2/ a variation of the response according to the duration of the study, to the number of follow-up visits, to the type of included patients, to the type of analysis, to the use or not of a placebo and to the use or not of a blind design. A review of the literature provides a qualitative prospect to the question. The objective was to describe the experimental designs used in the assessment of antidepressants and to identify possible innovations. The review of the literature 1/ has permitted to state precisely the limits of the studies in terms of internal validity (measurement of assessment criterions, attrition, unblinding, importance of the placebo response) and external validity (major difficulties with generalization of the studies’ results); 2/ leads to offer a multimodal evaluation of antidepressants in which observational studies would have their own place. Then the issue of measurement is specifically approached, using simulations. After exploring the impact of the experimental procedure at the level of the trial itself, the phenomenon is explored at a more global level. The choice of a reductio ad absurdum on the field of comparative effectiveness was decided. The aim was to compare the placebos of different antidepressants in a network meta-analysis. Indirect comparisons did not show any difference between placebos of antidepressants but a significant publication bias was detected. It does not allow drawing any firm conclusion on a result which is still obvious. This result invites discussion as to whether the evidence that we usually rely on provides us with a reasonable degree of certainty about the nature and effectiveness of our practices. Our results entail a new light on the controversy about the efficacy of antidepressants by replacing the debate on the epistemological ground
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Palpacuer, Clément. "Réévaluation de l'apport du nalméfène au traitement de l'alcoolodépendance." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1B038.
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Le nalméfène représente une option nouvelle dans le traitement de l’alcoolodépendance. Cette molécule a reçu une AMM européenne en 2013 pour réduire la consommation d’alcool des patients adultes ayant une consommation à risque élevé selon la classification de l’OMS (i.e. plus de 60 g d'alcool par jour pour les hommes, ou plus de 40 g par jour pour les femmes). Toutefois, les avis dans la littérature divergent quant à son intérêt. Nous avons donc souhaité réévaluer le rapport bénéfice-risque de cette molécule en appliquant des méthodes appartenant au domaine de la méta-recherche. Une première méta-analyse des essais randomisés contrôlés comparant le nalméfène par voie orale à un placebo nous a permis de mettre en évidence des tailles d’effet faibles sur les critères de consommation, avec un possible biais d’attrition dans les études. Dans une seconde méta-analyse en réseau évaluant l’efficacité, dans l’indication de réduction des consommations, du nalméfène à d’autres traitements également utilisés dans la prise en charge de l’alcoolodépendance, nous avons conclu à l’absence de preuve de haut niveau de l’efficacité des traitements pharmacologiques pour contrôler la consommation d'alcool chez les patients non abstinents souffrant de troubles liés à l’usage. Enfin, nous avons montré, à travers la réalisation d’un grand nombre de méta analyses, que les choix méthodologiques faits dans les essais randomisés contrôlés évaluant le nalméfène et la naltrexone dans la prise en charge de l’addiction à l’alcool entraînaient une variation substantielle de l’estimation de l’efficacité de ces deux traitements, phénomène également appelé « vibration de l’effet » des traitementsNalmefene is a new option in the treatment of alcohol dependence. It was approved by the European Medicines Agency to help reduce alcohol consumption in adults who consume more than 60 g of alcohol per day (for men) or more than 40 g per day (for women). However, researchers’ opinions on the interest of the drug are divided. We therefore planned direct and network meta-analyses to enable an objective reappraisal of the efficacy of nalmefene. A first meta-analysis of randomized controlled trials comparing oral nalmefene with placebo showed small effect sizes on consumption criteria with a possible attrition bias in the studies. In a second network meta-analysis evaluating the comparative efficacy of nalmefene to control drinking with other treatments also used in the management of alcohol dependence, we concluded that there was no high-grade evidence for pharmacological treatment to control drinking in non-abstinent patients with alcohol use disorders. Finally, we explored the vibration of effects in a large number of overlapping indirect meta-analyses comparing nalmefene versus naltrexone to reduce alcohol consumption. We demonstrated that the methodological choices made in randomized controlled trials resulted in a substantial variation in the effect sizes of these two treatments
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Davenport, Clare Frances. "Systematic reviews and meta-analyses of test accuracy : developing methods that meet practitioners' needs." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3427/.
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Testing can be a substantial driver of health care costs. Increase in test use over recent decades has occurred despite disappointing results from test accuracy evaluations. Poor quality and reporting of primary test accuracy studies and difficulties with understanding and application of test accuracy information are purported to be important contributors to this observed evidence ‘gap’. The objectives of this thesis were to: * Systematically review evidence concerning the understanding and application of test accuracy metrics. * Undertake primary research building on the review of understanding and application. * Assess whether the contribution of test accuracy reviews to the test accuracy evidence base is compromised by deficiencies in their contextual fit, or of included primary studies. Existing research concerned with understanding and application of test accuracy information is not driven by the needs of decision makers. Contrary to the prevailing view in the literature, findings of original research from this thesis demonstrate that probability revision is not a feature of diagnostic decision making. Choice of test accuracy metric however was shown to have a profound influence on diagnostic decision making. Deficiencies in question formulation and contextualisation of test accuracy reviews are undermining their contribution to the test accuracy evidence base.
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Bertolotti, Antoine. "Traitements locaux des condylomes ano-génitaux externes (revue systématique, méta-analyses, analyse poolée et méta-analyse en réseau²)." Thesis, Antilles, 2019. http://www.theses.fr/2019ANTI0412.
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Contexte: Il existe plusieurs traitements pour les condylomes ano-génitaux externes (CAE) cependant, aucune hiérarchie de traitement claire, n'est mentionnée dans les dernières recommandations. Objectifs: Comparer l'efficacité des traitements topiques et des traitements ablatifs pour la prise en charge des CAE. Méthodes: Tous les essais cliniques comparatifs et randomisés (ECR) de 12 bibliothèques numériques comparant des adultes immunocompétents avec des CAE ayant reçu au moins un traitement administré par le médecin ou auto appliqué par le patient ont été inclus. L’évaluation du risque de biais a suivi les recommandations Cochrane. Le critère d'évaluation de l'étude était la réponse lésionnelle complète (RLC) après évaluation du traitement. Des méta-analyses, des analyses poolées puis une méta-analyse réseau ont été réalisées. Résultats: Soixante-dix ECR (9 931 patients) ont été inclus. Tous les ECR, sauf quatre présentaient un risque élevé de biais. Méta-analyse en réseau: les traitements les plus efficaces comparativement au placebo étaient la chirurgie (RR 10,54 ; IC95% 4,53-24,52), une combinaison de traitement ablatif et d’imiquimod (RR 7,52 ; IC95% 4,53-24,52) et l'électrochirurgie (RR 7,10 ; IC95% 3,47-14,53). Les valeurs de SUCRA confirmaient la supériorité de la chirurgie (90,9%), d’une combinaison d’un traitement ablatif avec de l’imiquimod (79,8%) et de l'électrochirurgie (77,1%). Les TAP les plus efficaces étaient la podophyllotoxine 0,5 % solution (63,5%) et la podophyllotoxine à 0,5 % crème (62,2%). Conclusions: La majorité des ECR inclus sont à faible niveau de preuve. La chirurgie et l'électrochirurgie semblent être supérieures aux autres traitementsBackground: While several treatments exist for anogenital warts (AGWs), no clear treatment hierarchy is mentioned in the latest guidelines. Objectives: To compare the efficacy of topical treatments and ablative procedures for the management of AGWs. Methods: Twelve electronic databases were systematically searched. All randomized controlled trials (RCTs) comparing immunocompetent adults with AGWs who received at least 1 provider-administered or patient-administered treatment in at least 1 parallel group were included. Risk of bias assessment followed the Cochrane Handbook. Study endpoints were clearance, recurrence, side effects (SE) and complete lesion response (CLR) after treatment assessment. Meta-analyses, pooled analysis then network meta-analysis were performed. Results: Seventy RCTs (9,931 patients) were included. All but 4 RCTs had a high risk of bias. In network meta-analysis (only CLR assessment): a network geometry was constructed based on 49 of the 70 RCTs. The most efficacious treatments compared to placebo were surgery (RR 10.54; CI95% 4.53-24.52), association of ablative therapy and imiquimod (RR 7.52; CI95% 4.53-24.52), and electrosurgery (RR 7.10; CI95% 3.47-14.53). SUCRA values confirmed the superiority of surgery (90.9%), association of ablative therapy and imiquimod (79.8%), and electrosurgery (77.1%). The most efficacious patient-administered treatments were podophyllotoxin 0.5% solution (63.5%) and podophyllotoxin 0.5% cream (62.2%). Conclusions: Most included RCTs have low-level evidence. Surgery and electrosurgery seem to be superior to other treatments. Combined therapy should be more evaluated in future RCT
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Herbert, James Leslie. "Discrepancies in intimate violence reporting for men and women's violence a meta-analysis /." Connect to thesis, 2006. http://portal.ecu.edu.au/adt-public/adt-ECU2008.0006.html.
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Moody, Ann Michelle. "A meta-analytic review of the performance-cue bias." Thesis, Montana State University, 2005. http://etd.lib.montana.edu/etd/2005/moody/MoodyA0505.pdf.
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Meehan, Anna, and Henrik Evertsson. "Genetic and Environmental Influences on Psychopathic Personality Traits : A Meta-Analytic Review." Thesis, Örebro universitet, Institutionen för juridik, psykologi och socialt arbete, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-27685.
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To understand the etiology of psychopathic personality traits and thus in the long run to be able to develop successful prevention, a first step is to find out what role genetic and environmental effects play. A meta-review of 15 twin studies (N=26, 981), was conducted to estimate the magnitude of genetic and environmental influences on psychopathic personality traits. The results show that additive genetic (heritable) factors and non-shared environmental factors each explain 50% of the variance in psychopathic personality traits, while shared environmental factors were of no importance. Measure, informant, age, and sex were investigated as potential moderators showing that informant had an impact on the findings. This meta-analysis provides a structured synthesis of the relative genetic and environmental contributions in psychopathic personality traits through various stages of development and across sex.För att förstå etiologin av psykopatiska personlighetsdrag och därmed i det långa loppet kunna utveckla framgångsrik prevention, är ett första steg att klargöra vilken roll genetiska och miljömässiga effekter spelar. En meta-översikt på 15 tvillingstudier (N=26,981), genomfördes för att uppskatta i vilken grad genetiska och miljömässiga faktorer påverkar psykopatiska personlighetsdrag. Resultaten visade att additiva genetiska (ärftliga) och unika miljömässiga faktorer förklarar 50% var av variansen i psykopatiska personlighetsdrag, medan delade miljömässiga faktorer inte var av betydelse. Mått, informant, ålder och kön undersöktes som potentiella moderatorer och visade att informant påverkade resultaten. Denna meta-analys ger en strukturerad syntes av de relativa genetiska och miljömässiga bidrag som påverkar psykopatiska personlighetsdrag genom olika utvecklingsstadier och mellan könen.
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Lacefield, Katharine. "A meta-analytic approach to examining psychosocial correlates of risk in HIV-diagnosed and HIV-nondiagnosed men who have sex with men." Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5801.
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Human Immunodeficiency Virus (HIV) continues to disproportionately affect men who have sex with men (MSM). Gay, bisexual, and other MSM are estimated to account for two percent of the population, yet they constitute more than half of all individuals living with HIV in the United States (Centers for Disease Control [CDC], 2010). Collectively, both HIV-diagnosed (HIV-D) and HIV-nondiagnosed (HIV-ND) MSM report a variety of reasons for intentional and unintentional nonuse of condoms. Depending on partner status, HIV-D MSM are in the unique position of having the potential both to increase risk of infecting others with HIV and to expose themselves to further complication (e.g., superinfection) when they engage in unprotected anal intercourse (UAI). HIV-ND MSM are at risk of seroconversion each time they engage in UAI with an infected partner or partner of unknown HIV status. Elucidating reasons for continued engagement in UAI specific to both HIV-D and HIV-ND MSM likely is an important step in the process of effective prevention. The current study employed meta-analytic methods to evaluate HIV-risk correlates in both HIV-D and HIV-ND MSM. In addition to several individual risk correlates, within the context of the Information-Motivation-Behavioral Skills Model, Behavioral Skills variables were related to condom use in HIV-ND MSM and Motivation variables were related to condom use in both HIV-D and HIV-ND MSM. A sufficient number of studies were not available to examine Information-based risk correlates in either subgroup. Results of the present study may guide future best practice in harm reduction for both HIV-D and HIV-ND MSM.Ph.D.
Doctorate
Psychology
Sciences
Psychology; Clinical Psychology
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Philibert, Aurore. "Méthodes de méta-analyse pour l’estimation des émissions de N2O par les sols agricoles." Thesis, Paris, AgroParisTech, 2012. http://www.theses.fr/2012AGPT0072/document.
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Le terme de méta-analyse désigne l'analyse statique d'un large ensemble de résultats provenant d'études individuelles pour un même sujet donné. Cette approche est de plus en plus étudiée dans différents domaines, notamment en agronomie. Dans cette discipline, une revue bibliographique réalisée dans le cadre de la thèse a cependant montré que les méta-analyses n'étaient pas toujours de bonne qualité. Les méta-analyses effectuées en agronomie étudient ainsi très rarement la robustesse de leurs conclusions aux données utilisées et aux méthodes statistiques. L'objectif de cette thèse est de démontrer et d'illustrer l'importance des analyses de sensibilité dans le cadre de la méta-analyse en s'appuyant sur l'exemple de l'estimation des émissions de N2O provenant des sols agricoles. L'estimation des émissions de protoxyde d'azote (N2O) est réalisée à l'échelle mondaile par le Groupe d'experts intergouvernemental sur l'évolution du climat (GIEC). Le N2O est un puissant gaz à effet de serre avec un pouvoir de réchauffement 298 fois plus puissant que le CO2 sur une période de 100 ans. Les émissions de N2O ont la particularité de présenter une forte variabilité spatiale et temporelle. Deux bases de données sont utilisées dans ce travail : la base de données de Rochette et Janzen (2005) et celle de Stehfest et Bouwman (2006). Elles recensent de nombreuses mesures d'émissions de N2O réparties dans le monde provenant d'études publiées et ont joué un rôle important lors des estimations d'émissions de N2O réalisées par le GIEC. Les résultats montrent l'intérêt des modèles à effets aléatoires pour estimer les émissions de NO2 issues de sols agricoles. Ils sont bien adaptés à la structure des données (observations répétées sur un même site pour différentes doses d'engrais, avec plusieurs sites considérés). Ils permettent de distinguer la variabilité inter-sites de la variabilité intra-site et d'estimer l'effet de la dose d'engrais azoté sur les émissions de NO2. Dans ce mémoire, l'analyse de la sensibilité des estimations à la forme de la relation "Emission de N2O / Dose d'engrais azoté" a montré qu'une relation exponentielle était plus adaptée. Il apparait ainsi souhaitable de remplacer le facteur d'émission constant du GIEC (1% d'émission quelque soit la dose d'engrais azoté) par un facteur variable qui augmenterait en fonction de la dose. Nous n'avons par contre pas identifié de différence importante entre les méthodes d'inférence fréquentiste et bayésienne. Deux approches ont été proposées pour inclure des variables de milieu et de pratiques culturales dans les estimations de N2O. La méthode Random Forest permet de gérer les données manquantes et présente les meilleures prédictions d'émission de N2O. Les modèles à effets aléatoires permettent eux de prendre en compte ces variables explicatives par le biais d'une ou plusieurs mesures d'émission de N2O. Cette méthode permet de prédire les émissions de N2O pour des doses non testées comme le cas non fertilisé en parcelles agricoles. Les résultats de cette méthode sont cependant sensibles au plan d'expérience utilisé localement pour mesurer les émissions de N2OThe term meta-analysis refers to the statistical analysis of a large set of results coming from individual studies about the same topic. This approach is increasingly used in various areas, including agronomy. In this domain however, a bibliographic review conducted by this thesis, showed that meta-analyses were not always of good quality. Meta-analyses in agronomy very seldom study the robustness of their findings relative to data quality and statistical methods.The objective of this thesis is to demonstrate and illustrate the importance of sensitivity analysis in the context of meta-analysis and as an example this is based on the estimation of N2O emissions from agricultural soils. The estimation of emissions of nitrous oxide (N2O) is made at the worldwide level by the Intergovernmental Panel on Climate Change (IPCC). N2O is a potent greenhouse gas with a global warming power 298 times greater than the one of CO2 over a 100 year period. The key characteristics of N2O emissions are a significant spatial and time variability. Two databases are used for this work: the database of Rochette and Janzen (2005) and the one of Stehfest and Bouwman (2006). They collect numerous worldwide N2O emissions measurements from published studies and have played a significant role in the estimation of N2O emissions produced by the IPCC. The results show the value of random effects models in order to estimate N2O emissions from agricultural soils. They are well suited to the structure of the data (repeated observations on the same site for different doses of fertilizers, with several sites considered). They allow to differentiate the inter-site and intra-site variability and to estimate the effect of the rate of nitrogen fertilize on the N2O emissions. In this paper, the analysis of the sensitivity of the estimations to the shape of the relationship "Emission of N2O / N fertilizer dose" has shown that an exponential relationship would be the most appropriate. Therefore it would be appropriate to replace the constant emission factor of the IPCC (1% emission whatever the dose of nitrogen fertilizer) by a variable factor which would increase with the dose. On the other hand we did not identify significant differences between frequentist and Bayesian inference methods. Two approaches have been proposed to include environmental variables and cropping practices in the estimates of N2O. The first one using the Random Forest method allows managing missing data and provides the best N2O emissions predictions. The other one, based on random effects models allow to take into account these explanatory variables via one or several measurements of N2O. They allow predicting N2O emissions for non-tested doses in unfertilized farmer's field. However their results are sensitive to the experimental design used locally to measure N2O emissions
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Sidén, Eriksson Patrik, and Jonas Höglund. "Lageroptimering med hjälp av multikriterieanalys : En fallstudie hos KUBALs centrallager." Thesis, Mittuniversitetet, Avdelningen för informations- och kommunikationssystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-28102.
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This thesis deals with control of stock in an inventory, focusing on inventory placement. The purpose of this thesis is to reduce the transport distance within the main stock house while gathering inventory. This will be achieved by reconstructing the inventory placement in consideration with how frequently the inventories get picked and mass of the inventory. In particular, the literature and the data that is collected from the company´s business system have laid the foundation for the thesis. In general, interviews and observations also contributed to the data collection. To fulfill the aim and to produce arbitrary results, two issues have been developed regarding which attributes that should determine the position of the inventory in the stock house and how to obtain a more effective inventory structure? The authors have jointly produced a result of suggestions for future inventory placement in terms of picking frequency and weight. Initially a situation analysis was conducted to identify known problems with the inventory´s placement and storage systems. The problems that were identified were that the inventory placement has no consideration regarding picking frequency. To determine the most frequent picked inventory an ABC analysis was conducted. All of the inventories were spread out throughout the whole stock house. To take in account, the additional criterion, which was weight, a multi-criteria analysis was performed in combination with the ABC analysis. The results of the combined analysis provided that the basis for drawing up concepts for future inventory placement. The proposal includes optimized inventory placements in different zones of the most frequently picked inventory with weight as an additional criterion.Arbetet behandlar området lagerstyrning med inriktning på optimering av artikelplacering. Syftet med arbetet är att minska transportsträckor inom centrallagret, detta genom en omstrukturerad artikelplacering med hänsyn till plockfrekvens och tyngd. I synnerhet har litteratur samt insamlad data från företagets affärssystem lagt grunden för arbetet. I allmänhet har intervjuer och observationer också bidragit till datainsamling. För att uppfylla arbetets syfte och ta fram ett godtyckligt resultat har två frågeställningar tagits fram angående vilka attribut som bör avgöra en artikels position i lagret samt hur en effektivare lagerstruktur kan erhållas. Författarna har gemensamt arbetat fram ett resultat i form av ett förslag för framtida artikelplacering sett till plockfrekvens och tyngd. Inledningsvis genomfördes en nulägesanalys för att identifiera kända problem med artikelplacering och lagersystem. De problem som identifierades var att artikelplaceringen sker utan underlag för plockfrekvens. För att utröna de mest frekventa artiklarna genomfördes en ABC-analys. Samtliga artiklar lokaliserades utspridda över hela lagret. För att ta hänsyn till ytterligare ett kriterium, vilket var tyngd, genomfördes multikriterieanalys i kombination med ABC-analys. Resultatet av den kombinerade analysen gav underlag för att ta fram förslag för framtida artikelplacering. Förslaget innehåller optimerade artikelplaceringar inom olika zoner för de mest plockfrekventa artiklarna med tyngd som ytterligare kriterium.
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Carter, David E. "A Meta-Analysis of Early Life Influences on Behavior." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342728891.
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HERBERT, James, and herbiej@bigpond com. "DISCREPANCIES IN INTIMATE VIOLENCE REPORTING FOR MEN AND WOMEN?S VIOLENCE: A META-ANALYSIS." Edith Cowan University. Business And Law: School Of Law And Justice, 2006. http://adt.ecu.edu.au/adt-public/adt-ECU2008.0006.html.
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The report of intimate violence is often taken on face value in research. With no gold standard existing, one partner?s report is often an accepted measure of violence in the relationship. This discrepancy in reporting between intimate partners has been thoroughly examined, yet researchers still debate the reliability of single partner reporting. The current study extends upon the Archer (1999) meta-analysis of intimate violence discrepancy reporting, and includes current studies, instruments and research methods in the analysis. This study examines the discrepancy effect among thirty-four samples from studies of heterosexual intimate violence, finding that the discrepancy in general was sizeable for men?s violence, and that different study conditions yield differing levels of discrepancy. This discrepancy level is a major issue when conducting quantitative research, especially typological studies, which utilise estimation and extrapolation of prevalence levels, and when violence data is used to evaluate recidivism. The current study identifies situations where the discrepancy is likely to be high and makes recommendations to improve the accuracy of the data being used to advise government policy and spending.
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Ronco, Sharron L. (Sharron Lee). "Comparison of Methods for Computation and Cumulation of Effect Sizes in Meta-Analysis." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc331655/.
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This study examined the statistical consequences of employing various methods of computing and cumulating effect sizes in meta-analysis. Six methods of computing effect size, and three techniques for combining study outcomes, were compared. Effect size metrics were calculated with one-group and pooled standardizing denominators, corrected for bias and for unreliability of measurement, and weighted by sample size and by sample variance. Cumulating techniques employed as units of analysis the effect size, the study, and an average study effect. In order to determine whether outcomes might vary with the size of the meta-analysis, mean effect sizes were also compared for two smaller subsets of studies.
An existing meta-analysis of 60 studies examining the effectiveness of computer-based instruction was used as a data base for this investigation. Recomputation of the original study data under the six different effect size formulas showed no significant difference among the metrics. Maintaining the independence of the data by using only one effect size per study, whether a single or averaged effect, produced a higher mean effect size than averaging all effect sizes together, although the difference did not reach statistical significance. The sampling distribution of effect size means approached that of the population of 60 studies for subsets consisting of 40 studies, but not for subsets of 20 studies.
Results of this study indicated that the researcher may choose any of the methods for effect size calculation or cumulation without fear of biasing the outcome of the metaanalysis. If weighted effect sizes are to be used, care must be taken to avoid giving undue influence to studies which may have large sample sizes, but not necessarily be the most meaningful, theoretically representative, or elegantly designed. It is important for the researcher to locate all relevant studies on the topic under investigation, since selective or even random sampling may bias the results of small meta-analyses.
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Elliott, Jesse. "Benefits and Harms of Testosterone Replacement Therapy in Hypogonadal Men: A Systematic Review and Network Meta-analysis." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34092.
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Testosterone products comprise a multi-billion dollar industry; however, Health Canada and the United States Food and Drug Administration have issued statements of concern about their safety, and their benefits are unclear. In the first phase of this study, we performed a systematic review of the current evidence for the benefits of testosterone replacement therapy. In the second phase, we analyzed the evidence from randomized controlled trials for the benefits of testosterone replacement therapy (depression, quality of life, erectile function, libido, total testosterone level). In the third phase, we analyzed data for harms (cardiovascular death, myocardial infarction, stroke, newly diagnosed prostate cancer, coronary artery disease or diabetes, serious adverse events, withdrawals due to adverse events, erythrocytosis) from randomized controlled trials and non-randomized studies. In general, most included studies had a short duration and were poorly reported. Additional high-quality research into the long-term safety of testosterone products is needed.
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Faul, Dinelle. "Kindgesentreerde spelterapie en sandkasspelterapie met 'n kind met die Aspergersindroom / D Faul." Thesis, North-West University, 2013. http://hdl.handle.net/10394/10119.
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The purpose of this study was to research the therapeutic outcomes achieved by a five year-old boy with Asperger Syndrome (AS), by means of non-directive processes of child centred play therapy (CCP) and sand tray play therapy (STP). In this investigative-descriptive qualitative research design, a saturated, holistic, intrinsic single case study was used as research method. The therapeutic process, events and outcomes of a unique single case within the context of AS, non-directive play therapy and the interactional-pattern analysis (IPA), are described. This study was motivated by the fact that the researcher disposed of data for a unique single case study that could contribute meaningfully to the need for a research database that describes effective therapeutic interventions and outcomes with children with AS. From the perspective of Rogerian person-centred theory (RPT), the literature study focused on an integrated discussion of AS, CCP and STP by means of 17 interpersonal variables of the interactional-pattern analysis (IPA). The following data sources was investigated: interviews with parents and teachers; CCP-sessions of J recorded on video; photos of some of J’s STP-sessions and the therapists’ process notes. Triangulation was used to evaluate the various categories of therapeutic outcomes from different viewpoints and to give meaning to them. The conclusions indicated that this boy with AS had used the non-directive processes of CCP and STP to achieve various therapeutic outcomes in the areas of: imaginary play; dramatic play; social interaction with the therapist, parents, family, teachers, his peer group and with strangers; traumatic experiences during visits to the doctor and bath times; identification, expressing and regulating emotions; and minimising acting out behaviour. Therapeutic outcomes have been demonstrated in 8 IPA-variables, namely: empathy, defining of relationships, potential to evoke acceptance or rejection, sincere interest and congruent conduct, control, emotional distance, problem solving and aspects relating to the presenting problem. The conclusion was reached that the conduct of the boy with AS as well as his mother and the therapist, played a mutual role in achieving his therapeutic outcomes within the 17 IPA-variables. The unstructured process of the non-directive play (CCP and STP) was utilised by a young child with AS to achieve therapeutic outcomes that relate to his everyday existence. A final conclusion is that involving the boy’s mother in his therapy and utilising an adapted Filial play program, enabled the mother to make emotional contact with her son and to diminish conflict between them. Guidelines for therapists are suggested with regard to non-directive responding in therapeutic contexts as found in this study. Furthermore, the contribution of this research to Psychology as science and discipline, is presented. Limitations of this study are indicated and recommendations for further research are made.Thesis (Ph.D. (Psigologie))--North-West University, Vaal Triangle Campus, 2013
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Kitayama, Ken, Eddy R. Segura, Jordan E. Lake, Amaya G. Perez-Brumer, Catherine E. Oldenburg, Bethany A. Myers, Paria Pourjavaheri, Chinomnso N. Okorie, Robinson L. Cabello, and Jesse L. Clark. "Syphilis in the Americas: a protocol for a systematic review of syphilis prevalence and incidence in four high-risk groups, 1980–2016." Biomed Central Ltd, 2017. http://hdl.handle.net/10757/622278.
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Background: Syphilis infection has recently resurfaced as a significant public health problem. Although there has been a tremendous amount of research on the epidemiology of syphilis, there has been limited work done to synthesize the extensive body of research and systematically estimate patterns of disease within high-risk groups in the Americas. The purpose of this systematic review and meta-analysis is to (1) summarize recent patterns of syphilis infection in North and South America among four high-risk groups (MSM, transgender women, sex workers, and incarcerated individuals) from 1980 to 2016, (2) identify and differentiate regional geographic epidemiologic characteristics, and (3) compare the epidemics of the economically developed countries of North America from the developing countries and public health systems of Latin America and the Caribbean. Methods/design: Primary studies reporting syphilis prevalence and/or incidence in at least one of the four high-risk groups will be identified from Medline/PubMed, Embase, Lilacs, SciELO, The Cochrane Library, Web of Science, Scopus, ProQuest, CINAHL, Clase, and Periódica, as well as "gray" literature sources (conference abstracts, country reports, etc.). Studies published from 1980 through 2016 will be included. Data will be extracted from studies meeting inclusion and exclusion criteria and a random effects meta-analysis of prevalence and incidence estimates will be conducted. Heterogeneity, risk of bias, and publication bias will be assessed. Pooled prevalence and incidence estimates will be calculated for comparisons based on geographic region, risk factors, and time period. Discussion: Our systematic review and meta-analysis aims to contribute to an improved understanding of global epidemiologic patterns of syphilis infection in most-at-risk populations. Through systematic classification of the existing literature, and comparison of disease patterns across regional, temporal and socio-behavioral differences, we hope to improve public health surveillance and improve efforts to control the spread of disease across the Americas. Systematic review registration: PROSPERO CRD42016047306.
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Mallet, Philippe. "Analyse multiéchelle de carbones pyrolytiques." Toulouse 3, 2014. http://thesesups.ups-tlse.fr/2738/.
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Les Pyrocarbones sont des matériaux polyromatiques -graphéniques- obtenus par CVD/CVI qui sont souvent utilisés en tant qu'interfase ou en tant que matrice dans des composites C/C pour l'industrie aéronautique et la réalisation de freins, tuyères de fusées etc. Bien que non limitées à ce domaine d'application, cet exemple montre que leurs propriétés mécaniques et leur résistance aux températures extrêmes sont des qualités qu'il est primordial de déterminer. Dans ce but, une étape d'identification des matériaux est nécessaire afin de créer une base de données reliant la description des matériaux à leurs propriétés. Le travail de cette thèse s'est donc porté sur la description structurale (caractère cristallographique), nano-texturale (degré de perfection et d'ordre des graphènes au sein des domaines anisotropes) et structurale (étendues et disposition relative des domaines anisotropes) de certains de ces matériaux, les pyrocarbones laminaires (des trois types dits 'rugueux', 'lisses', et 'régénérés'). Il est articulé autour de deux techniques majeures qui sont la spectroscopie Raman et la microscopie électronique en transmission, complété par la diffraction des rayons X. Le volet spectroscopie Raman montre une étude de l'évolution des différentes bandes caractéristiques du matériau (bande G, générée par les vibrations du réseau, et bande D, générée par les défauts) et de leurs importances respectives (aires A ou intensités I), comme le rapport ID/IG, en fonction de la longueur d'onde excitatrice et en fonction de la taille moyenne des cristallites déterminées par diffusion de neutrons et diffraction des rayons X. Ce travail montre notamment que pour de petites tailles de cristallite (< 6nm), une nouvelle contribution à l'intensité de la bande D de même position spectrale apparaît. Cette approche novatrice par rapport aux travaux antérieurs permet de rendre compte parfaitement des observations expérimentales dans le domaine ultraviolet, visible et infrarouge. Afin de compléter cette étude, une série de cokes de brai a été étudiée et montre, en cohérence avec les pyrocarbones, une relation linéaire entre la largeur de la bande G et les tailles de cristallites lorsqu'elles font moins de ˜ 10nm. Dans le volet microscopie électronique en transmission, une méthodologie préalablement mise au point au laboratoire et validée pour la caractérisation multi-échelle quantifiée de pyrocarbones de type pshérulitiques isotropes a été utilisée pour la première fois pour la caractérisation de pyrocarbones laminaires. Pour le recours à plusieurs modes de la microscopie électronique (diffraction électronique à aire sélectionnée, imagerie de fond noir, imagerie de franges de réseau), elle a permis, dans une certaine mesure, d'évaluer qualitativement et/ou quantitativement les caractéristiques texturales et nanotexturales respectives et discriminantes des différents types de pyrocarbones étudiés. Le travail a aussi mis en évidence les limitations de la méthodologie à son application pour le type particulier des matériaux de l'étudePyrocarbons are polyromatic- graphenic- materials obtained by CVD / CVI and are often used as an interphase or as a matrix in C / C composites for the aerospace industry ans the production of brakes, rocket nozzles etc. . . Although not limited to this application domain, this example shows that their mechanical properties and heat resistance are qualities that it is essential to determine and predict. For this purpose, accurate material identification is needed to create a database linking the description of materials to their properties. The work of this thesis is focused on describing the structure (crystallographic point of view), nanotexture (degree of both perfection and order of grapheme layers within anisotropic domains), and texture (extension and relative arrangement of anisotropic domains) of a specific class of these materials, namely laminar pyrocarbons (wich include three kinds of them, known as 'rough', 'smooth' and 'regenerated'). It is mostly based on two major techniques wich are Raman spectroscopy and transmission electron microscopy, completed by X-ray diffraction. The section dedicated to Raman spectroscopy shows a study of the evolution of the various bands characteristic of the material (typically, the G band, generated by the lattice vibrations, and the D band, which is generated by defects) and their respective contributions (areas A or intensities I) as the ID/IG ratio which depends on both the exciting wavelength and the average crystallite size determined by neutron scattering and X-ray diffraction. This work shows that, in particular for small crystallite sizes (< 6 nm), a further contribution to the D band intensity at the same spectral position appears. In comparison to previous works, this innovative approach can account perfectly for the experimental observations recorded for various excitation wave lengths ranging from ultraviolet, to visible, and then to infrared. To complete this study, a series of pitch cokes was studied and shows, consistently with the pyrocarbons, a linear relationship between the width of the G band and the crystallite sizes the latter are less than ˜10nm. The section dedicated to the transmission electron microscopy utilizes a methodology previously developed and validated at CEMES for the quantified multi-scale characterization of another type of pyrocarbons, namely isotropic, spherulitic pyrocarbons has been used for the first time for the characterization of laminar pyrocarbons. By using several modes of the electron microscopy (electron diffraction with selected area diffraction, dark field images, lattice-fringe images), it was possible to evaluate qualitatively and/or quantitatively the structural and nano-textural respectively and to discriminate between the various pyrocarbons studied. This work has also highlighted the limitations of the methodology for its application to the peculiar type of the materials studied
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Dockes, Jérôme. "Statistical models for comprehensive meta-analysis of neuroimaging studies." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLT048.
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La neuroimagerie permet d’étudier les liens entre la structure et le fonctionnement du cerveau. Des milliers d’études de neuroimagerie sont publiées chaque année. Il est difficile d’exploiter cette grande quantité de résultats. En effet, chaque étude manque de puissance statistique et peut reporter beaucoup de faux positifs. De plus, certains effets sont spécifiques à un protocole expérimental et difficile à reproduire. Les méta-analyses rassemblent plusieurs études pour identifier les associations entre structures anatomiques et processus cognitifs qui sont établies de manière consistante dans la littérature. Les méthodes classiques de méta-analyse commencent par constituer un échantillon d’études focalisées sur un même processus mental ou une même maladie. Ensuite, un test statistique permet de délimiter les régions cérébrales dans lesquelles le nombre d’observations reportées est significatif. Dans cette thèse, nous introduisons une nouvelle forme de méta-analyse, qui s’attache à construire des prédictions plutôt qu’à tester des hypothèses. Nous introduisons des modèles statistiques qui prédisent la distribution spatiale des observations neurologiques à partir de la description textuelle d’une expérience, d’un processus cognitif ou d’une maladie cérébrale. Notre approche est basée sur l’apprentissage statistique supervisé qui fournit un cadre classique pour évaluer et comparer les modèles. Nous construisons le plus grand jeu de données d’études de neuroimagerie et de coordonnées stéréotaxiques existant, qui rassemble plus de 13 000 publications. Dans la dernière partie, nous nous intéressons au décodage: prédire des états psychologiques à partir de l’activité cérébrale. La méta-analyse standard est un outil indispensable pour distinguer les vraies découvertes du bruit et des artefacts parmi les résultats publiés en neuroimagerie. Cette thèse introduit des méthodes adaptées à la méta-analyse prédictive. Cette approche est complémentaire de la méta-analyse standard, et aide à interpréter les résultats d’études de neuroimagerie ainsi qu’à formuler des hypothèses ou des a priori statistiquesThousands of neuroimaging studies are published every year. Exploiting this huge amount of results is difficult. Indeed, individual studies lack statistical power and report many spurious findings. Even genuine effects are often specific to particular experimental settings and difficult to reproduce. Meta- analysis aggregates studies to identify consistent trends in reported associations between brain structure and behavior. The standard approach to meta-analysis starts by gathering a sample of studies that investigate a same mental process or disease.Then, a statistical test delineates brain regions where there is a significant agreement among reported findings. In this thesis, we develop a different kind of metaanalysis that focuses on prediction rather than hypothesis testing. We build predictive models that map textual descriptions of experiments, mental processes or diseases to anatomical regions in the brain. Our supervised learning approach comes with a natural quantitative evaluation framework, and we conduct extensive experiments to validate and compare statistical models. We collect and share the largest existing dataset of neuroimaging studies and stereotactic coordinates. This dataset contains the full text and locations of neurological observations for over 13 000 publications. In the last part, we turn to decoding: inferring mental states from brain activity.We perform this task through meta-analysis of fMRI statistical maps collected from an online data repository. We use fMRI data to distinguish a wide range of mental conditions. Standard meta-analysis is an essential tool to distinguish true discoveries from noise and artifacts. This thesis introduces methods for predictive metaanalysis, which complement the standard approach and help interpret neuroimaging results and formulate hypotheses or formal statistical priors
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Di, Gessa Giorgio. "Simple strategies for variance uncertainty in meta-analysis." Connect to e-thesis, 2007. http://theses.gla.ac.uk/128/.
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Thesis (M.Sc.(R)) - University of Glasgow, 2007.M.Sc.(R) thesis submitted to the Department of Statistics, Faculty of Information and Mathematical Sciences, University of Glasgow, 2007. Includes bibliographical references. Print version also available.
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González, David Andrés. "Evaluating Preventative Interventions for Depression and Related Outcomes: a Meta-analysis." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc700044/.
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The burden of depression requires modalities other than individual psychotherapy if we are to reduce it. Over the past two decades preventative programs for depression have been developed and refined for different populations. The six years since the last meta-analysis of preventative interventions—inclusive of all program types—have seen a number of new studies. The current study used the greater statistical power provided by these new studies to analyze moderators of, and sub-group differences in, the effect of these interventions on depression. Moreover, this meta-analysis synthesized effect sizes for outcomes other than, but often related to, depression (e.g., anxiety) and for within-group change scores with the goal of better informing program implementation and evaluation. Twenty-nine studies met inclusion criteria and indicated that small, robust effects exist for reductions in depression diagnoses and symptomatology. Significant effects were also observed for anxiety, general health, and social functioning.
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Fauzan, Norsiah. "The effects of metacognitive strategies on reading comprehension : a quantitative synthesis and the empirical investigation." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/1086/.
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Bae, Jeffrey, and Robert Kobleski. "Adherence in Exercise Meta-Analyses: Assessment and Effect on Study Outcomes." The University of Arizona, 2005. http://hdl.handle.net/10150/624700.
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Class of 2005 AbstractObjective: The purpose of this study was to explore whether current meta-analyses on exercise interventions assess adherence and/or compliance of the studies included in the meta-analyses and to determine if subject adherence had any effect on outcomes of the analyses. Methods: Data was collected through a search of the MEDLINE database using the key words exercise, adherence, compliance, clinical trials, and meta-analysis. Data on study title, author, number of studies screened, number in meta-analysis, range of sample sizes, total number of subjects, primary intervention, primary outcome, how study quality was assessed, how adherence was assessed, whether adherence was used as a control variable, and did adherence affect the outcome was recorded on a paper and pencil data extraction form. Data was analyzed by constructing a table describing the meta-analyses and calculating the number and percent of analyses that included adherence. The table allowed for the evaluation of the strength and methodology of each piece of literature with respect to acknowledging adherence as a significant variable in the strength and legitimacy of each analysis. Results: Nineteen meta-analyses met our search criteria and were evaluated. Five of the nineteen meta-analyses (26 percent) described a method for assessing adherence. It was found that none of these used adherence as a control variable. Four of the nineteen meta-analyses did not assess the quality of the studies contained within the analysis. One of these meta-analyses suggested that adherence may have confounded outcomes, but did not provide any data to address their concerns. Conclusions: In meta-analyses, adherence is unlikely to be addressed. Current meta-analyses frequently lack methods for assessing adherence, and do not use adherence as a control variable. Whether adherence to exercise regimens affects outcomes cannot be determined from current meta-analyses.
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Jönsson, Linnéa, and Matilda Lennartsson. "”Alltså jag ser ju mest positivt, ju mer jag ser desto mer positivt ser jag” : En kvalitativ intervjustudie om upplevelsen av frivilligt ensamstående föräldraskap via assisterad befruktning i Sverige." Thesis, Linnéuniversitetet, Institutionen för psykologi (PSY), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-95849.
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Syftet med den aktuella kvalitativa studien var att belysa frivilligt ensamstående föräldrars (FEF) upplevelser för att bidra till ökad förståelse och kunskap om hur det är att överväga, bli och vara FEF. Sju semistrukturerade intervjuer genomfördes och analyserades genom tematisk analys, vilket resulterade i fem huvudteman: Så upplevs FEF-skapet, Ta steget att bli FEF, Stöd från ett nätverk är viktigt som FEF, Hur FEF blir bemötta av sin omgivning och Tankar om framtiden. Mödrarna upplevde FEF-skapet som övervägande positivt och enklare än förväntat. Både för- och nackdelar nämndes och stöd från ett nätverk beskrevs vara extra viktigt. Mödrarna var medvetna om att de bryter mot kärnfamiljsnormen. Från omgivningen hade de mestadels mött positiva reaktioner men även en del negativa reaktioner och fördomar, främst rörande avsaknaden av en pappa. Mödrarna uppgav olika skäl till att bli FEF och beslutsprocessen rapporterades övervägande som enkel. Samtidigt uttrycktes viss ambivalens då FEF inte var deras förstahandsval, men ansågs mest optimalt utifrån deras förutsättningar.The aim of this qualitative study was to make visible the experiences of single mothers by choice (SMC) with the purpose of contributing to increased understanding and knowledge of what it is like to consider, become and be a SMC. Seven semi-structured interviews were conducted and analyzed through thematic analysis, resulting in five main themes: The experience of motherhood as SMC, Making the choice to become SMC, Support from a network is important as SMC, How SMC is met by their surroundings and Thoughts on the future. The mothers perceived motherhood as SMC as mostly positive and easier than expected. Both advantages and disadvantages were mentioned and support from a network was described as especially important. The mothers were aware that they are violating the nuclear family norm. From their surroundings, they had mostly encountered positive reactions but also some negative reactions and prejudices, mainly concerning the absence of a father. The mothers stated different reasons for becoming SMC and the decision-making process was predominantly reported as simple. At the same time, some ambivalence was expressed as motherhood as SMC was not their first hand choice, but was considered the best choice based on their situation.
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Skäremo, Holmberg Jonas. "Torsten Brodén och kontinuumhypotesen med en introduktion till naiv mängdlära." Thesis, Uppsala universitet, Algebra och geometri, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-171975.
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Cavalcante, Alliny Souza de Assis. "Estudo meta-analítico de características relacionadas à qualidade da carne e da carcaça em bovinos." Universidade Federal de Goiás, 2017. http://repositorio.bc.ufg.br/tede/handle/tede/7391.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
The number of the Brazilian herd has been increasing exponentially, so it is necessary to adjust the production systems and performance with the objective of favoring the increase of production and a supply of meat in Brazil. A pay for the national court is only a live weight and there is no carcass yield of the animals, however with future changes in the scenario. Several factors may directly or indirectly influence the quality of beef, such as softness, fat and palatability of the meat that may influence the final price of the product. Some evaluations are performed to evidence the body composition, no animal, they are EM, BF and IMF. These evaluations are performed for evaluation of the meat composition and fat thickness of no animal. Due to the large number of researches on the quality of the material, the work was conducted with the aim of obtaining combined means of meat and carcass quality indicators, as well as to verify the effect of certain factors on these data using a meta-analysis as tool. The research was performed in the PubMed and Scielo sites from 2009 to 2016 based on 49 scientific papers containing AOL, EG and EGP8 carried out in cattle, totaling an average of 9,142 animals analyzed in relation to the carcass characteristics. Of the database for the purpose of sex, age, breed and weight of the animal. The results of this study demonstrated that the measurements were performed in the carcass, presenting averages higher than those performed by ultrasonography.
O número do rebanho brasileiro vem crescendo exponencialmente, por este motivo, faz-se necessário alguns ajustes nos sistemas e desempenhos produtivos com objetivo de favorecer o aumento da produção e a oferta de carne no Brasil. Diversos fatores podem afetar de forma direta ou indireta na característica de qualidade da carne bovina, tais como na maciez, gordura e palatabilidade da carne que podem influenciar no preço final do produto. Algumas avaliações são realizadas para evidenciar a composição da carne no animal, são elas AOL, EG, EGP8, peso, PI, PF, PCQ, MAR e maciez. Estas características são realizadas para avaliação da composição da carne e espessura de gordura no animal. Devido ao grande número de pesquisas sobre qualidade de carne o presente trabalho foi conduzido com objetivo de se obter médias combinadas de parâmetros indicadores de qualidade de carne e carcaça, bem como verificar o efeito de determinados fatores sobre estes parâmetros utilizando a meta-análise como ferramenta. Os registros foram identificados através de pesquisa de banco de dados nos sites PubMed e Scielo no período de 2009 a 2016 com base em 49 artigos científicos que continham assuntos relacionados AOL, EG, EGP8 e maciez realizados em bovinos, totalizando uma média de 9.142 animais analisados em relação às características de carcaça e carne. A construção do banco de dados foi baseada em informações relativas ao sexo, idade, raça e peso do animal. Os resultados deste estudo demonstraram que as mensurações realizadas diretamente na carcaça apresentaram médias superiores às realizadas por ultrassonografia.
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Molin, Laurent. "Analyse du système Met-enképhalinergique dans les gliomes humains." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10235.
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Les systemes opiaces endogenes (les neuropeptides opiaces endogenes et leurs recepteurs), consideres pendant longtemps exclusivement comme des agents impliques dans la transmission d'informations entre les neurones, participent a la regulation de la proliferation de nombreux types cellulaires normaux, notamment les astrocytes, et neoplasiques. Cependant, le peu de travaux realises dans ce domaine sur les tumeurs gliales et l'existence d'une activite inhibitrice exercee par la met-enkephaline, un neuropeptide opiace endogene, sur la croissance des astrocytes normaux justifiaient qu'une etude approfondie de l'activite du systeme met-enkephalinergique soit entreprise dans les gliomes. Les resultats obtenus montrent que l'expression de differents elements de ce systeme diminue au cours de la progression maligne des gliomes: diminution d'expression du gene codant pour la met-enkephaline, diminution du taux intratumoral de met-enkephaline, diminution du nombre des sites de fixation de la met-enkephaline. Par ailleurs, in vitro, la met-enkephaline ne modifie pas la croissance des cellules de lignees de gliomes. Differentes hypotheses sont proposees pour expliquer ces alterations. La diminution du taux de met-enkephaline intratumoral et du nombre de ses recepteurs membranaires pourrait permettre aux cellules gliales tumorales d'echapper au controle negatif exerce par ce peptide sur leur croissance et ainsi favoriser leur progression vers des degres plus eleves de malignite
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COLAGROSSI, MARCO. "META-ANALYSIS AND META-REGRESSION ANALYSIS IN ECONOMICS: METHODOLOGY AND APPLICATIONS." Doctoral thesis, Università Cattolica del Sacro Cuore, 2017. http://hdl.handle.net/10280/19697.
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A partire dagli anni ’80, la diffusione dei metodi statistici, abbinata ai progressi nelle capacità computazionali dei personal computers, ha progressivamente facilitato i ricercatori nel testare empiricamente le proprie teorie. Gli economisti sono diventati in grado di eseguire milioni di regressioni prima di pranzo senza abbandonare le proprie scrivanie. Purtroppo, ciò ha portato ad un accumulo di evidenze spesso eterogenee, quando non contradditorie se non esplicitamente in conflitto. Per affrontare il problema, questa tesi fornirà una panoramica dei metodi meta-analitici disponibili in economia. Nella prima parte verranno introdotte le intuizioni alla base dei modelli gerarchici a fattori fissi e casuali capaci di risolvere le problematicità derivanti dalla presenza di osservazioni non indipendenti. Verrà inoltre affrontato il tema dell’errore sistematico di pubblicazione in presenza di elevata eterogeneità tra gli studi. La metodologia verrà successivamente applicata, nella seconda e terza parte, a due diverse aree della letteratura economica: l’impatto del rapporto banca-impresa sulle prestazioni aziendali e il dibattito sulla relazione fra democrazia e crescita. Mentre nel primo caso la correlazione negativa non è influenzata da fattori specifici ai singoli paesi, il contrario è vero per spiegare l’impatto (statisticamente non significativo) delle istituzioni democratiche sullo sviluppo economico. Quali siano questi fattori è però meno chiaro; gli studiosi non hanno ancora individuato le co-variate – o la corretta misurazione di esse – capaci di spiegare questa discussa relazione.Starting in the late 1980s, improved computing performances and spread knowledge of statistical methods allowed researchers to put their theories to test. Formerly constrained economists became able [to] run millions of regressions before lunch without leaving their desks. Unfortunately, this led to an accumulation of often conflicting evidences. To address such issue, this thesis will provide an overview of the meta-analysis methods available in economics. The first paper will explain the intuitions behind fixed and random effects models in such a framework. It will then detail how multilevel modelling can help overcome hierarchical dependence issues. Finally, it will address the problem of publication bias in presence of high between-studies heterogeneity. Such methods will be then applied, in the second and third papers, to two different areas of the economics literature: the effect of relationship banking on firm performances and the democracy and growth conundrum. Results are far-reaching. While in the first case the documented negative relation is not driven by country-specific characteristics the opposite is true for the (statistically insignificant) impact of democratic institutions on economic growth. What these characteristics are is, however, less clear. Scholars have not yet found the covariates - or their suitable proxies - that matter to explain such much-debated relationship.
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Ronget, Victor. "The relationships linking age and body mass to vital rates : a comparative perspective in birds and mammals." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1304/document.
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Les individus varient en termes de taux de survie et de taux de reproduction. Les variations de ces taux vitaux peuvent être reliées aux caractéristiques des individus tel que la masse et l’âge. Des modèles démographiques ont été développé pour prendre en compte ces variations dans les populations naturelles et permettre de faire des prédictions pour gérer les populations naturelles. Cependant, la quantité de données démographiques nécessaire pour construire ces modèles n’est pas disponible dans toutes les populations. Pour surmonter ce problème, j’ai pendant ma thèse décrit les patrons généraux des relations reliant l’âge et la masse aux taux vitaux chez les mammifères et les oiseaux. En utilisant les données de la littérature, j’ai pu décrire les patrons généraux de ces relations et mis en évidence les facteurs biologiques pouvant expliquer les variations de ces relations entre les espèces et les populations. Dans un premier temps je me suis concentrer sur le lien entre la masse des individus et leurs taux vitaux. J’ai montré un effet positif de la masse des jeunes sur la survie des jeunes. J’ai ensuite mis évidence l’effet des différentes causes de mortalité sur cette relation avec par exemple un effet négatif de la prédation sur l’intensité de cette relation. J’ai ensuite montré un effet positif de la masse de la mère sur la masse du jeune et enfin que la probabilité de reproduction d’une femelle est impactée positivement par sa masse. Dans une seconde partie, je me suis concentré sur le lien entre l’âge et la survie chez les mammifères. Pour décrire ce lien, nous avons construit une base de données MALDDABA compilant les relations reliant l’âge aux taux vitaux chez les populations naturelles de mammifères que nous avons extraits de tables de vie issues de la littérature. En utilisant ces données, nous avons démontré que les femelles vivent en moyenne plus longtemps que les mâles chez les mammifères en milieu naturelles. J’ai enfin décrit les avantages at les inconvénients des différentes métriques de longévité et proposé de nouvelles méthodes pour décrire la relation entre l’âge et le taux de mortalité. Avec cette thèse, je mets en avant l’utilisation des approches comparatives pour mieux comprendre quels sont les facteurs qui influence la dynamique des populations naturellesIndividuals varies in terms of survival and reproduction. Most of those variations in vital rates can be linked to individual characteristics such as age or body mass. Demographic models were developed to make prediction on those trait-structured populations and are now often used to manage wild populations. However, the amount of data needed to perform those models is not available for every populations. To overcome this issue, I tried in my thesis to assess the general patterns for the relationships linking age and body mass to the vital rates in birds and mammals. By comparing relationship extracted in the literature, I was then able to assess the general effect of body or age on vital rates as well as the biological factor explaining the variation of those relationships between species and populations. I first assess how body mass influence vital rates in birds and mammals. I demonstrated the positive effect of offspring body mass on offspring survival and showed how the relative importance of each causes of mortality influence this relationship, with for instance a negative effect of the predation rate on the intensity of the relationship. I also showed that mother body mass is positively related to offspring body mass and that heavier mother are also more likely to reproduce. On a second part I focused on describing the relationship between age and survival for mammals. We built a database MALDDABA compiling all relationships linking vital rates to age for wild mammals from life tables reported in the literature. Using life table data compiled in the database I was able to demonstrate that females live on average longer than males in wild populations of mammals. I then critically assess the metrics of longevity and provide new insight to describe the relationship between mortality and age. With my thesis I provided new views on the uses of comparative approach to highlight the major factors influencing the population dynamic in the wild
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Beyer, Stefanie. "Charakteristika, Therapie und Outcome von Patienten mit spinalem Glioblastom oder Gliosarkom - Ein systematischer Review." Doctoral thesis, Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-209213.
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Gliome stellen mit 30-40 % die häufigsten intrakraniellen Tumoren dar. Darunter ist das Glioblastom, auch als Glioblastoma multiforme bezeichnet, mit ca. 50 % am stärksten vertreten und macht somit allein etwa 20 % aller Hirntumoren aus (Russell und Rubinstein 1989). Neben einer Metastasierung über den Liquor können diese Tumoren auch sehr selten als primäre Neubildung im Rückenmark vorkommen. Ebenso ist dort die Entwicklung eines sekundären Glioblastoms aus dem fortschreitenden Wachstum eines niedriggradigen Astrozytoms heraus möglich (Sure et al. 1997). Aufgrund ihres diffus infiltrativen Wachstums sowie der infausten Prognose wird das Glioblastom in der WHO-Klassifikation dem Tumorgrad IV zugeordnet (Louis et al. 2007).
Ziel dieser vorliegenden medizinischen Dissertation ist es, mit Hilfe einer Meta-Analyse individueller Patientendaten einen integrativen Überblick über die bereits vorhandene Forschung dieser seltenen Erkrankung zu erlangen. Aus einer umfangreichen Literaturrecherche resultierten 82 geeignete Publikationen, sodass von insgesamt 157 Patienten unter anderem Daten zum Veröffentlichungszeitraum, Alter und Geschlecht des Patienten, Tumorbiologie und –lokalisation sowie Therapie und Outcome erhoben werden konnten. In der statistischen Auswertung wurde die Korrelation dieser Faktoren eingehend untersucht mit dem Ziel, signifikante Aspekte herauszufiltern, die das Überleben von Patienten mit spinalem Glioblastom positiv beeinflussen können.
Trotz einer stetigen Verbesserung der bildgebenden Diagnostik durch Magnetresonanztomographie und Computertomographie sowie multimodaler Tumortherapie zeigte sich in der Auswertung der Ergebnisse, dass das mediane Überleben der Patienten mit spinalem Glioblastom bzw. Gliosarkom auf nur rund neun Monate zu beziffern ist.
Dabei konnten sowohl das Alter bei Diagnosestellung als auch das Jahr der Veröffentlichung der jeweiligen Patientenfälle als statistisch signifikante und somit bedeutende prognostische Faktoren im Hinblick auf die Überlebenszeit der Patienten identifiziert werden.
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Bagci, Gokhan Baris Kobe Donald Holm. "The nonadditive generalization of Klimontovich's S-theorem for open systems and Boltzmann's orthodes." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9124.
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Ledbetter, Nicole Verbeck Guido F. "Applications of nanomanipulation coupled to nanospray mass spectrometry in trace fiber analysis and cellular lipid analysis." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9760.
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Klint, Olsson Matilda, and Linnea Lönn. "En månad med flyktingkrisen : En analys av Rädda Barnens och Sverige för UNHCR:s videomaterial på Facebook." Thesis, Högskolan för lärande och kommunikation, Högskolan i Jönköping, HLK, Medie- och kommunikationsvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-29424.
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Den här uppsatsen undersökte hur medielogiken uttrycks i Rädda Barnens och Sverige för UNHCR:s videomaterial under flyktingkrisen september 2015. Då majoriteten av den medialiseringsrelaterade forskningen i Sverige har intresserat sig för partiledardebatter och politisk kommunikation finns det en kunskapslucka kring hur medielogiken formar andra sfärer i samhället. Denna studie avsåg att genom semiotisk analys och mulitmodal analys undersöka videomaterial i dessa två ideella organisationer, för att identifiera mediernas berättartekniker i dem. Sammanlagt analyserades fyra videoklipp i två ideella organisationers Facebook-sidor under september 2015 utifrån teorin om semiotik och medielogik. Två tydliga teman i videoklippen framträdde ur resultatet. Dessa benämnde vi som Flyktingkrisen som empati och Flyktingkrisen som verklighet. Ur dessa framkom fyra underteman. Dessa benämnde vi som dramatisering, dokumentering, reklamformat och nyhetsformat. Studiens resultat visade även att medielogiken personifiering förekommer starkt i samtliga av våra studieobjekt. Utifrån detta resultat kunde vi dra slutsatser kring genom vilka stereotyper personifieringen framkom i. Vår studie bidrar därmed till forskningsfältet med kunskap om stereotyper av flyktingar. I tidigare forskning av Ylva Brune (1998) urskiljs två sorters stereotyper av flyktingar: offer eller hot. Vidare menar Urban Ericsson (2001) att stereotypen den duktige flyktingen tenderar att förekomma i media endast på individnivå. I vårt material fann vi att en flykting gestaltades annorlunda än de stereotyper vi fann i vår tidigare forskning. Vi valde att kalla den här kategorin flyktingen som målmedveten då denne är fast besluten att ta sig fram trots omständigheterna. Vi fann även en icke tidigare dokumenterad framställning av flyktingar som likartad publiken när det gäller välfärdsbakgrund.The aim of this paper was to examine how media logic’s are expressed in Save the children’s and Sweden for UNHCR’s video material during the migrant crisis. Since the majority of the mediatization research in the Swedish context has focused on the party leaders and political communication, there is a lack of awareness regarding how media logic shapes other spheres in the community. This study’s objective was to examine video material through semiotic and multimodal analysis, to identify media logics. In total four videos from two nonprofit organizations, that were published in September 2015, were analyzed based on the understanding of media logics. Two distinctive themes appeared in the results. These were titled migrant crisis as empathy and migrant crisis as reality. From these, four subthemes appeared. These were titled dramatization, documentation, advertising formats and news format. The result shows that personalization occurs strongly in all of our study. Our study contributes to the research field with knowledge about stereotypes of refugees. We found a new kind of stereotype that we have chosen to call the determined refugee. The choice of name for this category is based on our interpretation of a refugee as determined to survive. In addition to the study’s contribution of how the representation of refugees among nonprofit organizations now take a new form, we also found a not previously documented representation of refugees like the crowd when it comes to the welfare background. Our study contributes to knowledge about how mediatization is expressed in strategic communication.
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Ohlsson, Linn, and Malin Martikainen. "Diagnostisering av projekt : En studie med utgångspunkt från SPA-ramverket." Thesis, Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-13881.
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The work in project has been around since humans began to hunt in groups, building bridges or building of the Great Wall of China. In 1960- and 70´s, the word project got their value it has today. A project means a work done during a decided time, with decided economy and non-recurring nature (Jansson and Ljung 2004). The projects had a general analytical model. It was used for all projects the organization engaged. Nowadays there are plenty of models that indicates how projects should be handled and organized (Engwall 2004). As an example there is a general project model based on five working step model (Jansson and Ljung 2004). This consists of analyzing the project idea, lead the planning, leading implementation work, leading the handover process and at the end closing out the project organization. Projects are divided into archetypes. Examples of these are utility projects, customer order projects, prod-uct development projects and market projects (Jansson and Ljung 2004). This has resulted in that a number of researchers have developed models for handling differ-ent types of projects. Ljung (2011) has developed SPA-framework for project analysis. This framework consists of three models of analysis. Analysis model 1, Strategic significance, ex-amining the project archetype. Analysis model 2, Operational logics, studies the result of the project, the decision-making process and the project phases. Analysis model 3, examines the Complexity of the project. When the project is analysed based on these models, the differ-ences of the projects are shown. Then the project manager can customize project management for its uniqueness. Our study investigated if the SPA-framework can be used to analyze the project and identify its distinctive characteristics. The result of the project analysis shows that SPA-framework can be used for this purpose. We used the three analytical models, Strategic significance, Op-erational Logic and Complexity, to formulate questions based on the result-, process- and or-ganization perspective. The analysis of the interviews revealed that all the projects analyzed, have specific distinctive characteristics. Our results demonstrate that there are both similari-ties and differences between the analyzed projects. Technical complexity is the most promi-nent complexity of the analysis. Four out of five projects received this type of complexity. Only one project received Structural complexity. Three projects had a hint of Contextual complexity.Projektarbetsformer har funnits alltsedan människan började jaga i grupp, bygga broar eller vid byggnationen av kinesiska muren. På 1960- och 70-talet fick begreppet projekt den bety-delse den har idag. Med projekt menas ett arbete av engångskaraktär som bedrivs under en bestämd tid med en bestämd kostnadsram (Jansson och Ljung 2004). Numera finns ett flertal modeller för projekthanteringen beskrivna i litteraturen (Engwall 2004). Ett exempel är Jans-son och Ljungs (2004) modell där projektledningsarbetet struktureras upp i fem arbets-steg/faser (Jansson och Ljung 2004). Dessa är att analysera projektidén, leda planeringsar-betet, leda realiseringsarbetet, leda överlämningsarbetet samt att till sist avveckla projektorga-nisationen. Projekt förekommer i en mängd olika typer. Exempel på dessa är interna föränd-ringsprojekt, kundorderprojekt, produktutvecklingsprojekt och marknadsprojekt (Jansson och Ljung 2004). Detta har resulterat i att fler forskare har tagit fram modeller för att stödja hante-ring av olika typer av projekt. Ljung (2011) har utvecklat ett ramverk för strukturerad projekt-analys (SPA). Ramverket består av tre analysmodeller. Analysmodell 1, Strategisk betydelse, undersöker vilken strategisk projektarketyp projektet har. Analysmodell 2, Operativ logik, studerar projektets leverabel, beslutsprocesser och faser. Analysmodell 3, Komplexitet, under-söker vilken typ av komplexitet projektet har. När projektet är analyserat enligt dessa modeller, ser projektledaren vilka särdrag projektet har. Projektledaren kan då anpassa pro-jekthanteringen efter dess särdrag. Vi har i vår studie undersökt och analyserat ett antal projekt i en tillämpning av SPA-ramverket. Vi har undersökt vilka särdrag som framträder genom analysen. Att använda denna modell är ett sätt att få en djupare förståelse för hur projektet är strukturerat samt vilka brister och fördelar hanteringen av projektet har. I vår studie har vi genom fem semistrukture-rade intervjuer undersökt om SPA- ramverket kan användas för att analysera projekt och finna dess särdrag. Resultatet av projektanalyserna visar att SPA-ramverket kan användas för att finna projektens särdrag. Med hjälp av de tre analysmodellerna Strategisk betydelse, Operativ logik och Komplexitet formulerades frågor grundade på resultat-, process och organiserings-perspektivet. I analysen av intervjuerna upptäcktes att alla projekt som analyserats har speci-fika särdrag. Studiens resultat visar att det finns både likheter och olikheter mellan de analyse-rade projekten.
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Boedeker, Peter. "Comparison of Heterogeneity and Heterogeneity Interval Estimators in Random-Effects Meta-Analysis." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157553/.
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Meta-analyses are conducted to synthesize the quantitative results of related studies. The random-effects meta-analysis model is based on the assumption that a distribution of true effects exists in the population. This distribution is often assumed to be normal with a mean and variance. The population variance, also called heterogeneity, can be estimated numerous ways. Accurate estimation of heterogeneity is necessary as a description of the distribution and for determining weights applied in the estimation of the summary effect when using inverse-variance weighting. To evaluate a wide range of estimators, we compared 16 estimators (Bayesian and non-Bayesian) of heterogeneity with regard to bias and mean square error over conditions based on reviews of educational and psychological meta-analyses. Three simulation conditions were varied: (a) sample size per meta-analysis, (b) true heterogeneity, and (c) sample size per effect size within each meta-analysis. Confidence or highest density intervals can be calculated for heterogeneity. The heterogeneity estimators that performed best over the widest range of conditions were paired with heterogeneity interval estimators. Interval estimators were evaluated based on coverage probability, interval width, and coverage of the estimated value. The combination of the Paule Manel estimator and Q-Profile interval method is recommended when synthesizing standardized mean difference effect sizes.
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Trinquart, Ludovic. "Impact, détection et correction du biais de publication dans la méta-analyse en réseau." Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05S025/document.
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La méta-analyse (MA) en réseau, en généralisant la MA conventionnelle, permet d'évaluer toutes les comparaisons deux à deux possibles entre interventions. Les biais de publication ont reçu peu d’attention dans ce contexte. Nous avons évalué l’impact des biais de publication en utilisant un réseau de 74 essais randomisés évaluant 12 antidépresseurs contre placebo enregistrés à la FDA et un réseau de 51 essais parmi les 74 dont les résultats étaient publiés. Nous avons montré comment les biais de publication biaisaient les quantités d'effet estimées et le classement des traitements. L'effet du biais de publication peut différer entre MA en réseau et MA conventionnelle en ce que les biais affectant un traitement peuvent affecter le classement de tous les traitements. Nous avons ensuite généralisé un test de détection des biais à la MA en réseau. Il est basé sur la comparaison entre les nombres attendu et observé d’essais avec résultats statistiquement significatifs sur l’ensemble du réseau. Nous avons montré par des études de simulation que le test proposé avait une puissance correcte après ajustement sur l’erreur de type I, excepté lorsque la variance inter-essais était élevée. Par ailleurs, le test indiquait un signal significatif de biais sur le réseau d’essais d’antidépresseurs publiés. Enfin, nous avons introduit deux modèles d’analyse de sensibilité des résultats d'une MA en réseau aux biais de publication: un modèle de méta-régression qui relie la quantité d’effet estimée à son erreur standard, et un modèle de sélection dans lequel on estime la propension d’un essai à être publié puis l’on redresse le poids des essais en fonction de cette propension. Nous les avons appliqués aux réseaux d’essais d’antidépresseurs. Ce test et ces modèles d'ajustement tirent leur force de tous les essais du réseau, sous l’hypothèse qu'un biais moyen commun opère sur toutes les branches du réseauNetwork meta-analysis (NMA), a generalization of conventional MA, allows for assessing all possible pairwise comparisons between multiple treatments. Reporting bias, a major threat to the validity of MA, has received little attention in the context of NMA. We assessed the impact of reporting bias empirically using data from 74 FDA-registered placebo-controlled trials of 12 antidepressants and their 51 matching publications. We showed how reporting bias biased NMA-based estimates of treatments efficacy and modified ranking. The effect of reporting bias in NMAs may differ from that in classical meta-analyses in that reporting bias affecting only one drug may affect the ranking of all drugs. Then, we extended a test to detect reporting bias in network of trials. It compares the number of expected trials with statistically significant results to the observed number of trials with significant p-values across the network. We showed through simulation studies that the test was fairly powerful after adjustment for size, except when between-trial variance was substantial. Besides, it showed evidence of bias in the network of published antidepressant trials. Finally, we introduced two methods of sensitivity analysis for reporting bias in NMA: a meta-regression model that allows the effect size to depend on its standard error and a selection model that estimates the propensity of trial results being published and in which trials with lower propensity are weighted up in the NMA model. We illustrated their use on the antidepressant datasets. The proposed test and adjustment models borrow strength from all trials across the network, under the assumption that conventional MAs in the network share a common mean bias mechanism
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Gustafsson, Isabell, and Alexandra Vikman. "I början men ändå mot livets slut : Unga kvinnors upplevelser av att leva med cancer." Thesis, Mälardalens högskola, Akademin för hälsa, vård och välfärd, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-12086.
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Ett cancerbesked hos kvinnor i ung ålder kan medföra upplevelser som aldrig tidigare förekommit i livet, en oviss framtid med mycket tankar och funderingar. Bristande kunskaper om cancersjukas upplevelser finns hos sjuksköterskor enligt tidigare forskning, och det leder till att patienterna inte får adekvat vård. Syftet med examensarbetet var att beskriva unga kvinnors upplevelser av att leva med cancer. Tre biografier innehållande fem berättelser analyserades utifrån en kvalitativ manifest innehållsanalys. Martinsens teori användes som teoretisk referensram, där hon belyser vikten av gemenskap mellan människor samt tryggheten i miljön. Analysen resulterade i fyra kategorier; upplevelsen av att få ett cancerbesked, viljan att leva, upplevelsen av trygghet i gemenskap och miljö, samt vetskapen om att livet kommer att ta slut. Framträdande upplevelser var hoppfullhet, viljan att bli frisk och livskraft. Trygghet var något betydelsefullt och kunde upplevas i samband i gemenskap och speciella miljöer. Resultatet uttryckte även upplevelser i form av förtvivlan, hopplöshet och sorg. Det är betydelsefullt för sjuksköterskor att få fördjupad kunskap om unga kvinnors upplevelser av att leva med cancer. Detta för att medvetet kunna skapa en individuell anpassad vård för cancersjuka patienter.A cancer diagnosis for young women can lead to experiences that earlier never occurred in life, an uncertain future with a lot of thoughts and reflections. Nurses lack of knowledge in cancer patients' experiences are known according to previous research, and this leads to that patients don’t recive adequate care. Purpose of this study was to describe young women's experiences of living with cancer. Three biographies consisting of five stories were analyzed from a qualitative manifest content analysis. Martinsen´s theory was used as theoretical framework, where she illuminates the importance of communion between people and the safety of the environment. Analysis resulted in four categories: the experience of getting a cancer diagnosis, the will to live, the experience of safety in the community and environment, and the knowledge that life will come to an end. Prominent experiences were hopefulness, desire to be healthy and vitality. Safety was something significant and could be experienced in context of community and special environments. The result also expressed experiences in form of despair, hopelessness and sadness. It is important for nurses to gain deeper knowledge about young women's experiences of living with cancer. This is to deliberately create an individualized care for cancer patients.