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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

Apport de l'épidémiologie moléculaire et des approches inférentielles dans l'analyse de l'émergence et des routes d'invasion de Xanthomonas citri pv. citri en Afrique, bactérie responsable du chancre asiatique des agrumes / No English title available

Leduc, Alice 01 April 2015 (has links)
La compréhension de l'émergence des maladies infectieuses végétales causées par les bactéries passe par l'identification des populations sources, des routes d'invasion et des voies de dissémination, ainsi que par l'estimation des paramètres biotiques et abiotiques associés. Xanthomonas citri pv. citri (Xcc) est l'agent pathogène responsable du chancre Asiatique des agrumes. La bactérie est distribuée dans plusieurs pays agrumicoles du monde et listée comme organisme de quarantaine par ceux où elle est absente. Nous avons abordé l'épidémiologie moléculaire de Xcc à deux échelles spatio-temporelles grâce à un schéma de 14 microsatellites (MLVA-14) et un schéma de 31 marqueurs minisatellites (MLVA-31). Le typage MLVA-14 s'est montré adapté au génotypage d'une bactérie monomorphe comme Xcc. Le typage MLVA-31 a permis de diviser le pathovar Xcc en quatre groupes génétiques distincts correspondant aux différences de gammes d'hôtes mise en évidence chez cette bactérie. Le pathotype A (souches à large gamme d'hôtes parmi les rutacées) est séparé en deux groupes génétiques, tandis que les pathotypes A* et Aw (souches à gamme d'hôtes restreinte au limettier Mexicain et quelques espèces proches) constituent chacun un groupe génétique. Alors que l'expansion géographique de Xcc depuis son aire d'origine dans la première moitié du XXème siècle a quasi exclusivement concerné un seul groupe génétique, trois des quatre groupes décrits ont contribué à l'émergence de Xcc en Afrique au cours de la dernière décennie. La bactérie est pré-adaptée et a été introduite avec son hôte depuis sa population d'origine, faisant de la barrière migratoire la seule étape à franchir pour rencontrer un succès d'invasion. L'objectif de cette thèse a été de décrire les différentes populations émergentes grâce à des approches d'épidémiologie moléculaire et inférentielles, et identifier les différentes origines, routes et acteurs de la dissémination. Nous avons dans un premier temps montré la coexistence de deux groupes génétiques distincts au Mali : DAPC1 qui est dispersé dans quatre provinces du pays et DAPC2 qui est resté cantonné à l'espace péri-urbain de Bamako. L'analyse de l'émergence de Xcc au Sénégal a révélé le succès invasif de DAPC2 dans un autre environnement. La structure des populations DAPC1 du Mali et DAPC2 du Sénégal suggèrent que les plants de pépinières constituent une voie de dissémination majeure dans ces pays. À l'opposé, DAPC2 de Bamako n'est pas détecté en pépinières au Mali et n'a pas montré de caractère invasif. L'existence d'une population « tête de pont » invasive de souches DAPC1 au Mali donnant lieu à une épidémie au Burkina Faso a été mise en évidence par une approche ABC (calcul Bayésien approché). Les populations DAPC2 du Mali et du Sénégal ne présentent pas de lien épidémiologique direct mais partagent des liens de parenté avec des souches présentes dans le sous-continent Indien. Dans un deuxième temps, l'analyse d'une population de souches appartenant au pathotype A* en Ethiopie nous a permis de procéder à des estimations de paramètres démographiques, tels que les tailles efficaces. Nous avons montré que l'approche inférentielle nous permettait d'éclairer l'histoire démographique de Xcc dans un cas d'émergence, et de mettre en avant une dynamique saisonnière accentuant probablement le déséquilibre mutation-dérive lié à la situation d'émergence. L'émergence de Xcc en Afrique est principalement associée aux activités humaines. Sa dissémination locale et globale peut alors être considérablement limitée par des mesures de gestion plus stricte au niveau des pépinières et des flux de commerces. / Several plant emerging infectious diseases are caused by bacteria. To improve our understanding of their emergence, a description of the emerging populations, the reconstruction of invasion routes and pathways, as well as the identification of involved biotic and abiotic parameters are fundamental. The bacterium Xanthomonas citri pv. citri (Xcc) is responsible for Asiatic citrus canker. It is present in many citrus producing countries and listed as a quarantine organism in canker-free countries.Two MLVA schemes were used for molecular epidemiological analyses of Xcc. The first one, MLVA-14, targeted 14 microsatellite markers, and is useful to describe the genetic diversity of this monomorphic bacterium. The second, MLVA-31, targeted 31 minisatellite markers, is suited to global epidemiology analyses. Based on MLVA-31 data, Xcc is divided in four genetic groups (referred to as DAPC clusters) corresponding to Xcc pathotype classification based on host range. Three pathotypes were described: pathotype A strains are able to infect most citrus species, while pathotypes A* and AW strains are naturally restricted to fewer host species.DAPC 1 is responsible for almost all cases of geographical expansion of Xcc over the first half of the 20th century, we show that three Xcc genetic clusters have emerged in Africa over the last decade. Xcc is pre-adapted to its host species. Invasive success of Xcc is then mostly conditioned by migration events. Our objectives were to describe these invasive populations using a molecular epidemiology approach and to assess the origin, routes and actors of this dissemination in Africa. Two genetic clusters were found in Mali: DAPC1 is present in four provinces while DAPC2 is restricted to the Bamako urban environment. In contrast, DAPC2 emerging populations in Senegal showed an invasive succes in an other environment. Populations structures of DAPC1 in Mali and DAPC2 in Senegal highlighted the role of nurseries in Xcc dissemination. On the contrary, DAPC2 strains in Bamako were not detected in Malian nurseries and showed a limited invasive success. Approximate Bayesian Computation highlighted an invasive bridgehead scenario between DAPC1 in Mali and Burkina Faso. DAPC2 populations in Mali and Senegal were not found epidemiologically related but were genetically related to strains previously reported from the Indian subcontinent.Demographic parameters inference, such as effective population sizes, were inferred from Ethiopian pathotype A* populations. The inference approach was useful to decipher the demographic history of this emerging population, and suggested seasonal fluctuations in population sizes over time.Emergence of Xcc in Africa was found strongly related to human activities. Therefore, the local and global dispersion could be limited by a better management of nurseries and trade.
412

Inovace produktového portfolia vybrané společnosti / Innovations Product Portfolio of a chosen Company

Makovičková, Martina January 2013 (has links)
The content of this thesis is to analyze the product portfolio of the company ECS Invention spol. s r. o. and a proposal for its innovation. Recommendations related to the product portfolio are included as well. The thesis is divided into two parts. The theoreticalpart is focused on theoretical and methodological background of strategic marketing and innovations. The practical part deals with application of the theoretical knowledge into practice.
413

Optimalizace materiálového toku v interní logistice u vybraného podniku / Optimization of the material flow in the internal logistics at the selected company

Huryta, Michal January 2014 (has links)
This Master's thesis deals with the optimization of the material flow between two areas of the production plant of the selected company. At the beginning of the thesis there is shown theoretical framework which is needed for subsequent analysis and determination of the proposals to improvement. In this part there is pointed out to the understanding of the process and the various concepts related to the process management. Furthermore, for the purposes of the application part there are selected and analyzed specific tools of lean manufacturing. These include for example the spaghetti diagram, the product / process matrix and the value stream mapping as the essential tool of this thesis. All this is complemented by ABC analysis. After that these methods are also applied in the practical part for solving the current project in the selected company. At first in solving the project there is dealt with the determination of the most problematic material flow between two areas of production plant. Then there is suggested the optimization solutions and all of this is also complemented by the economic evaluation of the whole project.
414

Optimalizace skladových zásob ve společnosti NET4GAS, s.r.o. / Optimization of inventory in NET4GAS, s.r.o.

Hynoušová, Zuzana January 2012 (has links)
This thesis deals with optimization of inventory of spare parts and maintenance materials in NET4GAS, s.r.o. The aim of the thesis is to sort the items stored in the company and to propose specific supply methodology for the year 2013. The thesis is divided into two parts. The first, theoretical part includes theoretical knowledge of inventory management together with the methods used in the managing process, it also introduces specific inventory management of spare parts and maintenance materials. The second, practical part describes NET4GAS, s.r.o., its current system of inventory management of spare parts and maintenance materials, it identifies the local current problems in inventory management, it proposes selection of appropriate methods of inventory optimization and it demonstrates their application to real data. For the classification of stored items is selected ABC method. To draw up the supply plan is primarily used bootstrap method (also called bootstrapping), which makes estimates of future consumption of spare parts and maintenance materials. The final section summarizes all the recommendations for improving the current inventory management.
415

Cálculo das sequências positiva e negativa em tempo real a partir do produto escalar de vetores espaciais: aplicações em compensadores de perturbações na rede. / Calculation of positive and negative sequences in real time by using space vectors dot products: applications to grid disturbances compensators.

Carvalho, Kelly Caroline Mingorancia de 02 February 2015 (has links)
O presente trabalho pretende aplicar o método de cálculo de componentes simétricas por produtos escalares de vetores espaciais para o cálculo dos sinais de referência de compensadores de perturbação. Outras metodologias de cálculo de corrente de referência são apresentadas, analisadas e comparadas com o método implementado. Uma revisão de vetores espaciais nos sistemas abc e 0 é feita para auxílio da explicação do método de extração de componentes simétricas. O método é inicialmente apresentado de forma generalista, de modo que é realizado o cálculo de componentes de sequência positiva, negativa e zero para um harmônico de ordem h. A autora apresenta algoritmos de exemplos práticos para uso em cálculo de corrente de referência incluindo as compensações de reativos da corrente fundamental, de harmônicos pré-selecionados e de desequilíbrios de carga. O método é analisado e validado por meio de simulações e resultados experimentais. / This work applies, for a disturbance compensator, a method for the calculation of the symmetrical components based on space vectors\' dot product. Other methods are presented, analyzed and compared with the proposed method. The symmetrical components calculation method is explained using a geometrical approach in abc and 0 basis. Initially, it is presented a general method that calculates the hth order positive, negative and zero sequence components of a current or voltage signal. Then, practical examples are presented for current compensation, which includes: fundamental reactive current compensation, fundamental negative sequence compensation and pre-selected order harmonics compensation. The method is analyzed and validated by simulation and experimental results.
416

Molecular characterization of fall armyworm (Spodoptera frugiperda) resistant to Vip3Aa20 protein expressed in corn / Caracterização molecular da lagarta do cartucho (Spodoptera frugiperda) resistente a proteína Vip3Aa20 expressa em milho

Fatoretto, Júlio César 27 April 2017 (has links)
Transgenic plants containing genes from Bacillus thuringiensis have been used as an alternative to chemical insecticides for insect pest control. The vegetative insecticidal proteins (Vip) secreted during the vegetative growth phase of bacteria are considered a second generation of insecticidal proteins since they do not share any structural or sequence homology with previously used crystal proteins (Cry) as well as having a wide insecticidal spectrum. One of the target pests for this protein is the fall armyworm (FAW) (Spodoptera frugiperda), the most important corn pest in South America. Previously it has been controlled by insecticides and maize expressing Cry proteins, but has rapidly evolved resistance to many control practices and remains a top concern for sustainable biotechnology control efforts. Thus, resistance characterization involving mode of action and genetics of resistance can help with Insect Resistance Management strategies, and improve the durability of control. In this dissertation, using two selected FAW population resistant to Vip3Aa20 Bt protein (Vip-R1and Vip-R2) we generated comparative proteomic and transcriptomic data among resistant and susceptible colonies. In the chapter 2, we bring FAW biology/ecology and Brazilian agriculture landscape data to support the high adaptive potential of this pest to genetically modified maize expressing Bt Cry proteins in Brazil. Proteomics studies in the chapter 3 revealed that neither Vip-R1 nor Vip-R2 showed difference between resistant and susceptible colonies either for Vip3Aa20 activation through proteolysis assay nor protein binding to the receptor. Transcriptomic sequencing and RNA-seq analysis in the chapter 4 showed strong evidence of ABC transporter genes associated with resistance as well as genes related to G-protein signaling pathway as downregulated. These results will be discussed in context of providing best management practices for managing FAW resistance to Vip, and extending the durability of Vip technology. / Plantas Transgênicas expressando genes de Bacillus thuringiensis (Bt) tem sido usadas como alternativa ao controle químico para controle de insetos praga. A proteina Vip (Vegetative Insecticide Protein) cuja secreção é realizada durante fase de crescimento da bacteria é considerada como segunda geração de proteinas inseticidas em função desta não apresentar similaridade de sequencias com todas as outras proteinas cristal (Cry), apresentando ainda maior espectro de controle de pragas. Uma das pragas alvo desta proteina é a lagarta-do-cartucho do milho (Spodoptera frugiperda), considerada a mais importante na cultura do milho na América do Sul. Larvas desta espécie foram sempre controladas com inseticidas e mais recentemente, milho expressando proteínas Cry. No entanto, esta praga tem desenvolvido resistência para várias ferramentas de controle, trazendo preocupação para a sustentabilidade das taticas de controle geradas através da biotecnologia. Dessa forma, estudos de caracterização da resistencia envolvendo modo de ação e characteristicas genéticas envolvidas com resistência pode contribuir para melhorar estratégias de Manejo de Resistencia de Insetos (IRM) e aumentar a durabilidade destas tecnologias para o controle. Nesta dissertação, foi gerado dados proteômicos e de transcriptoma comparando uma população de S. frugiperda resistente a Vip3Aa20 com a susceptivel. No capítulo 2, abordamos as características de bio-ecologia da praga associado ao sistema de cultivo suportando o alto potencial adaptativo desta espécie para hibridos de milho expressando proteinas Bt no Brazil. No capitulo 3, estudos de proteômica mostrou que Vip-R1 e Vip-R2 quando comparado com SUS, não demostraram diferenças para ativação da proteina nem ausencia de ligação da proteína com receptor de membrana no intestino do inseto. Dados de transcriptoma descritos no capitulo 5 mostrou forte evidências de que a baixa expressão de genes relacionados ao sistema transportador ABC pode estar associado com resistência bem como genes da via de sinalização das proteínas G. Estes resultados serão discutidos em um contexto para suportar boas praticas de manejo de resistência para lagarta-do-cartucho e assim estender a durabilidade da tecnologia Viptera® no campo.
417

Eliminace úzkých míst ve výrobě elektrických zařízení / Bottleneck Elimination in the Production of Electrical Devices

Horníková, Daniela January 2017 (has links)
This diploma thesis deals with eliminating of bottlenecks in a production of eletrical devices, focusing mainly on the production line. It analyzes the current situation and using value stream mapping for a selected product it identifies bottlenecks of the production process. Further it proposes remedial measures to improve current situation.
418

Hodnocení bonity zákazníků podniku / Financial Standing valuation of the Company´s Customers

Kočvarová, Soňa January 2007 (has links)
This master´s thesis analyses and values state-of-the-art of debts control in company Becker Acroma spol. s r.o. Includes projects and provisions which call into financial standing valuation of the company´s customers system which will be improves to debts control and which call into better customers solvent morale.
419

Studie řízení zásob ve výrobním podniku / Study of the supply management in production company

Janál, Michal January 2007 (has links)
The master’s thesis deals with study of the supply management in production company Česká zbrojovka, a.s. The theoretical solutions deal with spheres needed for determination of optimal supply of the specified materials. On the basis of an analysis of the actual state of affairs, conducted ABC analysis (analysis and calculation of the optimal supply for specified materials) contains the proposals and methods for economic order quantity for other inventory. The outputs of my thesis are the methods of the dealing with optimal supplies and the proposal.
420

Studie optimalizace procesu zásobování podniku / The Study of Optimalization Process Supply in Company

Kjeronský, Michal January 2009 (has links)
Main subject of this master thesis is inventory controlling in Siemens Elektromotory, s.r.o. (Ltd), plant Frenštát pod Radhoštěm. In theoretical part are described the essential topics as the controlling generally , then substance of the the inventory controlling and the importation of inventory for the company, their classification and reasons, why is it so important to go in for the inventory controlling. In the practical part the thesis describes current situation in the company and current controlling toolls in inventory field. Then is described the process of developing new inventrory controlling program and the contribution of this program for inventory management. In following part is performed the ABC analysis of invetory acording their proportion on the total consumption. Based on this part are formulated suggestions for setting up new consignment stocks and calculated the influence on the company asset management

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