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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.
471

Pratylenchus coffeae em cafeeiros: efeito de densidades populacionais do nematóide e testes com genótipos. / Pratylenchus coffeae in coffee plants: effect of initial population densities and tests with genotypes.

Melissa Dall'Oglio Tomazini 26 January 2004 (has links)
O nematóide das lesões Pratylenchus coffeae é um dos principais parasitos do cafeeiro e de outras culturas e sua variabilidade biológica, que dificulta a adoção de métodos de controle, contribui para aumentar a sua importância no Brasil. Pela importância da cafeicultura e a falta de estudos com esse nematóide no Brasil, foram realizados experimentos com dois de seus isolados (K5 e M2), com os objetivos de correlacionar densidades populacionais do nematóide aos danos causados e estabelecer possíveis fontes de resistência de cafeeiros ao isolado K5. Foram testadas diferentes densidades populacionais iniciais do isolado M2 em plantas (seis pares de folhas) e plântulas (dois pares de folhas) do cafeeiro arábico ‘Catuaí Vermelho’. As densidades populacionais utilizadas foram de 0, 333, 1.000, 3.000 e 9.000 nematóides por plântula ou planta. A avaliação ocorreu aproximadamente cinco (plântulas) e sete (plantas) meses após a inoculação. Os resultados mostraram que houve uma acentuada redução do crescimento das plântulas, bem como massa fresca das raízes e massa seca da parte aérea, já a partir das densidades mais baixas. A variação populacional (Pf/Pi) foi menor que um (1,0) para todas as densidades de inóculo, indicando que esta cultivar, no estágio de plântulas com dois pares de folhas, mostrou-se intolerante ao parasitismo. Em relação à inoculação das plantas, já com seis pares de folhas, não houve diferenças significativas nas variáveis analisadas e ocorreram decréscimos populacionais do nematóide, indicando que, nessas condições, ‘Catuaí Vermelho’ mostrou-se resistente ao isolado M2. Em relação ao isolado K5, foram realizados cinco experimentos, visando caracterizar as reações de genótipos de Coffea canephora ('Robusta' e 'Conilon'), além de C. arabica ‘Mundo Novo’, comparado às reações frente ao nematóide de galhas Meloidogyne incognita raça 2. No Experimento 1, foram utilizadas plantas de C. arabica ‘Mundo Novo’, inoculadas com 1.480 nematóides por planta (isolado K5 e M. incognita). Após sete meses da inoculação foi feita a avaliação, mostrando que o crescimento populacional dos nematóides foi alto e a reação de suscetibilidade. Mesmo em mudas desenvolvidas de cafeeiro ‘Mundo Novo’, o isolado K5 destacou-se como tão agressivo quanto M. incognita. Os outros genótipos testados, de C. canephora, foram inoculados com 3.000 nematóides por planta. Nos Experimentos 2 e 3, as linhagens IAC 4804 e IAC 4810 de ‘Robusta’ foram suscetíveis ao isolado K5, mas em um deles (IAC 4804) ocorreu grande variação entre as repetições em relação à M. incognita. Apenas o isolado K5 promoveu redução do crescimento do cafeeiro, evidenciado na variável massa fresca das raízes, em ambas as linhagens, sendo que IAC 4810 comportou-se como resistente a M. incognita. No caso de C. canephora ‘Conilon’, ambas as linhagens testadas (IAC 4764 e IAC 4765) foram resistentes ao isolado K5 e suscetíveis a M. incognita. / The lesion-nematode Pratylenchus coffeae is a major pest of coffee and other economic crops and its biological variability, which often makes difficult the adoption of control methods, contributes to increase the importance of this parasite in Brazil. Due to the importance of coffee production and the lack of studies involving this nematode species in Brazil, experiments were set with two of its available isolates (K5 and M2) to correlate initial population densities with the damage caused on coffee plants and to establish possible resistance sources in relation to the isolate K5. Different population densities of isolate M2 were tested in plants (six pairs of leaves) and seedlings (two pairs of leaves) of Coffea arabica ‘Catuaí Vermelho’. The population densities (Pi) were: 0, 333, 1.000, 3.000 and 9.000 nematodes per seedling or plant. The evaluation was done at approximately five (seedlings) and seven (plants) months after inoculation. The results showed that there was a marked reduction of the height, as well as root fresh weight and shoot dry weight of the seedlings, starting from the lower Pi values. The nematode population decreased (Pf/Pi < 1), indicating that this cultivar, at the seedling stage, was intolerant to parasitism. In relation to the inoculation of older plants, there were no significant differences in the growth parameters and the nematode population also decreased allowing ‘Catuaí Vermelho’ to be rated as resistant to the isolate M2. In relation to isolate K5, five experiments (referred to as 1, 2, 3, 4, and 5) were set to characterize the reaction of different genotypes of Coffea canephora ('Robusta' and 'Conilon') and C. arabica ‘Mundo Novo', as compared with their reaction to the root-knot nematode Meloidogyne incognita race 2. In Experiment 1, plants of C. arabica ‘Mundo Novo’ were inoculated with 1,480 nematodes per plant (K5 and M. incognita). The final evaluation after seven months of the inoculation showed a high populational increase of the nematodes and that both were pathogenic at a same extent. The other genotypes tested, belonging to C. canephora, were inoculated with 3,000 nematodes per plant. The genotypes (IAC 4804 and IAC 4810) of ‘Robusta’ were susceptible to isolate K5, but in one of them (IAC 4804) there was great variation among the repetitions in relation to M. incognita. The isolate K5 caused marked reduction in the growth of coffee Robusta plants as evidenced particularly through the root fresh weight values in both tested genotypes; in addition, IAC 4810 was rated as resistant to M. incognita. With regard to C. canephora 'Conilon', both tested genotypes (IAC 4764 and IAC 4765) were resistant to isolate K5 and susceptible to M. incognita.
472

Estudo da fauna fitonematológica na Mata Atlântica do estado de São Paulo e na Floresta Amazônica do estado do Mato Grosso / Study of the plant parasitic nematode fauna in the Atlantic Forest from São Paulo state and the Amazon Forest from Mato Grosso state, Brazil

Rosangela Aparecida da Silva 04 April 2008 (has links)
Realizou-se estudo da fauna de fitonematóides em dois municípios do estado de São Paulo (Pariquera-Açu e Cananéia) sob domínio da Mata Atlântica e dois do estado do Mato Grosso (Nova Maringá e Guarantã do Norte) sob domínio da Floresta Amazônica, com o objetivo de conhecer a diversidade de fitonematóides desses biomas e avaliar o efeito do uso agrícola do solo sobre a comunidade de fitonematóides. Para tanto, foram efetuadas amostragens em áreas de vegetação primária e em áreas próximas cultivadas. Para cada amostra, foram extraídos os nematóides de 200 cm³ de solo e em 10 gramas de raízes pela técnica de peneiramento combinada com flutuação em centrífuga com solução de sacarose. Em seguida, os espécimes foram mortos pelo calor e fixados em formalina. Os nematóides foram posteriormente quantificados, para determinação da abundância de cada táxon, sendo as identificações taxonômicas realizadas com base em características morfológicas e morfométricas. Os dados foram analisados com base na abundância, freqüência e índices de similaridade (Jaccard e Bray e Curtis). Assinalaram-se 34 gêneros e as identificações específicas foram efetuadas para 22 táxons. Para a espécie Aorolaimus banoae foram apresentadas novas características morfológicas e morfométricas. Observou-se que, com a retirada da vegetação primária e a implantação dos cultivos de plantas perenes ou anuais, houve intenso processo de redução da diversidade de fitonematóides e da introdução de novos táxons, o que resultou em baixa similaridade entre os locais de vegetação primária e aqueles cultivados, demostrando-se elevada influência da atividade agrícola sobre a comunidade de fitonematóides. / A study about plant parasitic nematode fauna was conducted in two municipalities from São Paulo State (Pariquera-Açu and Cananéia in the Atlantic Forest) and two from Mato Grosso State (Nova Maringá and Guarantã do Norte in the Amazon Forest), Brazil. The aims of this study were to evaluate the diversity of plant-parasitic nematode fauna in locations of primary and to evaluate the effect of agricultural land use on the plant parasitic nematode communities. Nematodes were extracted from 200 cm³ of soil and 10 grams of roots by a sieving and sugar flotations technique and fixed with formalin. Nematodes were counted for determination of abundances of each taxon and the taxonomic identification was based on morphological and morphometric features. The following variables were obtained: abundance, frequency and similarity indexes (Jaccard and Bray e Curtis). A total number of 34 genera were recorded and 22 taxons were identified at species level. Concerning Aorolaimus banoae species, new morphological and morphometric features were presented. It was observed that, after removal of primary vegetation and implantation of perennial or annual crops, occurred a conspicuous reduction of plant parasitic nematode diversity, associated with introduction of exotic species, resulting in low similarity between location of primary vegetation and the cultivated ones. The results demonstrated that the agricultural practices affect strongly the plant parasitic nematode communities.
473

Avaliação da capacidade reprodutiva de populações de Pratylenchus spp. frente a diferentes espécies vegetais / Reproductive fitness of Pratylenchus spp. populations in different plant species

Mauro Ferreira Bonfim Junior 03 February 2010 (has links)
Os nematoides que atualmente tem sido classificados como P. coffeae, demonstram ampla variabilidade morfológica, molecular e quanto à reação à diferentes hospedeiros. Por conseguinte, é essencial que se identifique corretamente as espécies e que se conheça a capacidade de parasitismo em alguns hospedeiros, para que se possa estabelecer medidas de controle e estimar eventuais riscos da entrada de um patógeno em uma área com hospedeiro suscetível. Neste sentido, a presente pesquisa propõe, numa primeira parte, uma medida de controle de P. jaehni (K5), que é muito agressivo à cafeeiro arábico, baseada no uso de plantas má hospedeiras. Na segunda parte deste trabalho é realizada uma caracterização da reação de diferentes espécies vegetais à quatro populações de Pratylenchus spp. Em virtude do exposto, este estudo objetivou avaliar a reação de diferentes cultivares de feijoeiro comum frente à P. jaehni (K5), visando seu possível uso no manejo de áreas cafeeiras infestadas e caracterizar a reação de diferentes espécies vegetais de importância econômica (café, porta-enxertos cítricos, banana e sorgo) frente à quatro populações de Pratylenchus spp. As populações inciais utilizadas nos experimentos variaram entre 180 e 200 nematóides. Em todos os experimentos, os nematóides foram extraídos das raízes pelo método de Coolen e D´Herde (1972) e, eventualmente, do substrato pelo método de Jenkins (1964). Foram realizados três ensaios: i) o primeiro com feijoeiro comum, onde todas as cultivares utilizadas foram resistentes à P. jaehni (K5), inclusive na réplica; ii) o segundo com porta-enxertos cítricos, no qual somente o limão-cravo foi hospedeiro de P. jaehni (K5); iii) o terceiro, no qual foi utilizado café, limão-cravo, banana e sorgo para o conhecimento das respectivas reações frente à 4 populações de Pratylenchus spp. Neste último experimento ocorreu uma reação hospedeira diferenciada para cada população. De acordo com os resultados, concluise que as cultivares de feijoeiro comum utilizadas apresentam potencial de uso em áreas cafeeiras infestadas por P. jaehni (K5), em consórcio ou em áreas de renovação de cafezal, e que as populações de Pratylenchus spp. são capazes de se reproduzir de forma diferenciada frente às espécies vegetais testadas. / Nematode populations that have been classified as P. coffeae show wide morphological, molecular and host range variability. Therefore, is essential the correct identification of the species and the knowledge about its parasitism capacity on some hosts, to ensure appropriate control measures and to estimate the entry risks of a pathogen in an area with susceptible host. In this sense, the present research report, firstly, propose a control measure of P. jaehni (K5), which is very aggressive to the arabic coffee, based on the use of poor host plants. In the second part, was carried out a host status evaluation of different plant species to four populations of Pratylenchus spp. In this context, were evaluated the reaction of different common bean cultivars to P. jaehni (K5), for its possible use in management of coffee areas infested with this nematode, and characterized the response of different economic important plant species (coffee, citrus rootstocks, banana and sorghum) to four populations of Pratylenchus spp (IB01P, IB02P, K5 e C1). The initial population used in experiments ranged between 180 and 200 nematodes. In all experiments, nematodes were extracted from roots by Coolen e D\'Herde´s method (1972) and eventually from the substrate by Jenkins´ method (1964). Three assays were conducted and results was as following: i) in the first one, with common bean, all tested cultivars were resistant to P. jaehni (K5), including the replica; ii) in the second one, with rootstocks, only rangpur lime was a good host of P. jaehni (K5); iii) in the third one, in which was used coffee, rangpur lime, banana and grain sorghum, was observed a differential host reaction for each nematode population evaluated. According to the present results, we suggest that common bean cultivars tested have great potential for use, or in intercropping or in crop rotation, in coffee areas infested by P. jaehni (K5) and populations of Pratylenchus spp. have different reproductive fitness in the plants species tested.
474

Ensaio clínico randomizado da nitazoxanida no tratamento de poliparasitoses intestinais em municípios da Zona da Mata, Minas Gerais / Random clinical test of the nitazoxanide in the treatment of intestinal poliparasitism in cities in Zona da Mata, Minas Gerais

Andrade, Elisabeth Campos de 26 March 2009 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-03T13:51:17Z No. of bitstreams: 1 elisabethcamposdeandrade.pdf: 1614173 bytes, checksum: 02bbfb073bbecc90f3e7f67d2c386c90 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-03T19:01:36Z (GMT) No. of bitstreams: 1 elisabethcamposdeandrade.pdf: 1614173 bytes, checksum: 02bbfb073bbecc90f3e7f67d2c386c90 (MD5) / Made available in DSpace on 2017-04-03T19:01:36Z (GMT). No. of bitstreams: 1 elisabethcamposdeandrade.pdf: 1614173 bytes, checksum: 02bbfb073bbecc90f3e7f67d2c386c90 (MD5) Previous issue date: 2009-03-26 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / As parasitoses intestinais são um importante problema de saúde pública principalmente nos países subdesenvolvidos ou em desenvolvimento. Embora o parasitismo intestinal seja amplamente reconhecido como relevante no contexto epidemiológico de diversas comunidades, os estudos sobre o assunto são ainda insuficientes, principalmente no Brasil. Em vista da dificuldade de diagnóstico específico das parasitoses, muitas vezes são realizados tratamentos empíricos com mais de uma droga. O objetivo principal do presente estudo foi avaliar a efetividade e segurança do uso de nitazoxanida no tratamento de poliparasitoses comparado à terapêutica tradicional ofertada pelo serviço público. Além deste objetivo, foi possível investigar a prevalência e os fatores associados às parasitoses intestinais na população de Colônia do Paiol, uma comunidade quilombola, na Zona da Mata, Minas Gerais. Na comunidade analisada, procedeuse um estudo transversal por censo, sendo que dos 425 moradores, 391 (92%) foram avaliados através de questionário estruturado e exame coproparasitológico. Os resultados mostraram uma alta positividade (63,8%), sendo as espécies patogênicas mais freqüentes Ascaris lumbricoides (22,4%) e Trichuris trichiura (17,9%). O poliparasitismo ocorreu em 36,5% dos investigados. O ensaio clínico, controlado, duplo cego, randomizado avaliou 65 indivíduos em dois grupos de tratamento. A taxa de cura foi de 32,4% e 38,7% com a nitazoxanida e com o tratamento convencional, respectivamente, mas esta diferença não foi estatisticamente significativa (p=0,599). A ocorrência de vômito (p= 0,031) esteve associada ao tratamento convencional e de urina esverdeada ao uso de nitazoxanida (p=0,002). Os outros efeitos adversos foram independentes da droga. Houve diferença estatisticamente significativa em relação à cor da pele e a taxa de cura para ambos os tratamentos. A menor eficácia efetividade foi apresentada pelos indivíduos de cor preta. São necessários outros estudos para esclarecer a baixa efetividade nos casos de poliparasitismo, assim como, reavaliar as práticas preventivas e terapêuticas, com o uso de novas drogas e de agentes de largo espectro, podendo a nitazoxanida ser uma droga alternativa neste contexto. Agrega-se às novas possibilidades terapêuticas, a necessidade de políticas públicas que garantam qualidade de vida, através de saneamento básico, educação para saúde e acesso ao sistema público de saúde, minimizando as iniqüidades na sociedade. / Intestinal parasitism is an important public health concern, chiefly in underdeveloped or developing countries. Although widely recognized as a relevant community epidemiological issue, intestinal parasitism has not been sufficiently studied in Brazil. Because specific diagnosis is difficult and generally cumbersome, empiric treatment, sometimes with more than one drug, is frequently employed. The main aim of this study was the assessment of the effectiveness and safety of nitazoxanide for the treatment of intestinal polyparasitism, as compared to traditional therapy provided by the public service. The study also investigated the prevalence of and factors associated with intestinal parasitism in the population of Colônia do Paiol, a quilombola community from the Zona da Mata, Minas Gerais, Brazil. A census-based cross-sectional study used a structured questionnaire and stool examination to assess 391 people (92%) of the 425 inhabitants of the community. The frequency of intestinal parasitism was as high as 63.8%, with predominance of Ascaris lumbricoides (22.4%) and Trichuris trichiura (17.9%). Polyparasitism occurred in 36.5% of those investigated. A double-blind randomized controlled trial assessed 65 individuals in two treatment groups. Cure rates were 32.4% and 38.7% with nitazoxanide and conventional treatment, respectively, but the difference was not statistically significant (p = 0.599). Vomiting (p = 0.031) was associated with conventional treatment and greenish urine with nitazoxanide use (p = 0.002). Other untoward effects were independent of which drug was used. There was a statistically significant difference concerning skin color and cure rates for both treatments. Dark-skinned subjects had lower cure rates. Further studies are necessary to clarify the reasons for the low effectiveness found in these cases of polyparasitism, and to reevaluate preventive and therapeutic approaches with new and broad-spectrum drugs, nitazoxanide being an option in this context. In addition to new therapeutic approaches, there is a clear need to develop public policies that, through the provision of basic sanitation, health education and access to the public health system, assure quality of life and minimize inequity.
475

The Role of Nursery Size and Plant Phenology on the Reproduction of and Relationships within a Fig-fig Wasp Nursery Pollination System

Krishnan, Anusha January 2014 (has links) (PDF)
Obligate nursery pollination mutualisms such as the fig–fig wasp system, with their central plant–pollinator mutualism associated with non-pollinating satellite wasp species, can function as closed system microcosms representative of tritrophic communities. In this system, enclosed inflorescences (syconia) function as sites of seed production, as well as brood-sites for the progeny of herbivorous mutualistic pollinators, non-pollinating gallers and parasitoids of the two. Plant reproductive traits such as inflorescence size (syconium volume) and within-plant phenology (within-tree asynchrony) as can affect inter-species relationships among the three trophic levels in such plant–herbivore–parasitoid systems. Induced or natural variations in such plant traits could influence various direct and indirect effects among the organisms in the community and could even lead to the formation of feedback cycles. Furthermore, changes in the abiotic environment could have major impacts on the biotic associations in the system either by affecting the community members directly, or through their effects on plant reproductive traits. Ficus racemosa with its fig wasp community comprised of a single herbivorous pollinator mutualist, three non-pollinating parasitic gallers and three non-pollinating parasitoids was used as a model to investigate: (1) the role of mutualistic and parasitic fig wasps in affecting within-tree phenology; (2) direct and indirect biotic associations between various groups of fig wasps (pollinators, gallers and parasitoids) and the influence of inflorescence size and within-tree phenology on them; and (3) variations in the reproduction of and the biotic associations between the organisms of the community under variable abiotic climatic conditions. Patterns of plant reproductive phenology are usually considered evolved responses directed at optimizing resource use, pollen receipt/donation schedules and seed dispersal for plant individuals. Within-plant reproductive synchrony or asynchrony can arise due to variation in floral initiation patterns, as well as from localised proximate mechanistic responses to interactants such as pollinators, parasites and herbivores which could affect floral longevity or fruit development time. The investigation was begun by exploring the role of a mutualistic pollinator, and for the first time in a brood-site mutualism, that of parasitic herbivores (gallers) and parasitoids in influencing within-plant reproductive phenology. Since a syconium functions as an inflorescence which develops into a fruit after pollination, investigations were carried out on the impact on syconium synchrony of fig wasps that began their development within the brood site syconium at pre-pollination, pollination, and post-pollination stages via their effects on the development time of individual syconia in Ficus racemosa. We found that syconium initiation patterns were not the only proximate mechanism for within-tree reproductive asynchrony, and that individual syconia (even within a tree) had highly plastic development times dependent on their sizes, pollination time and the species of wasp progeny developing within them. Syconium volume, pollination early in the pollen-receptive phase and presence of early-ovipositing galler progeny reduced syconium development time, whereas the presence of late-ovipositing parasitoid progeny or pollination late in the pollen-receptive phase increased syconium development time. These results suggest an ongoing tug-of-war between syconium inhabitants to modify syconium development times. Parasitic fig wasps pull in different directions to suit their own needs, such that final syconium development times are likely to be a compromise between conflicting demands from developing seeds and from different wasp species. Inter-species relationships among the three trophic levels in plant–herbivore–parasitoid systems can potentially include various direct and indirect effects possibly mediated by induced or natural variations in plant traits. Analysing the seed and fig wasp compositions of microcosm replicates, i.e. individual syconia, shows that besides direct competition for resources and predator–prey interactions, the F. racemosa community also displays exploitative or apparent competition and trait-mediated indirect interactions. Syconium volume and within-tree asynchrony were reproductive plant traits that not only affected plant–herbivore and plant–parasitoid associations, but also possibly modified herbivore–herbivore and herbivore–parasitoid interactions. Our results also indicated that the reciprocal effects of higher trophic level fauna on plant traits (and vice versa) within this system drive a positive feedback cycle between syconium inhabitants and within-tree reproductive asynchrony. In the F. racemosa system, abiotic environmental factors could affect the reproduction of mutualistic pollinators, non-mutualistic parasites and seed production via seasonal changes in plant reproductive traits such as syconium volume within-tree asynchrony. Temperature, relative humidity and rainfall defined four seasons: winter; hot days, cold nights; summer and wet seasons. Syconium volumes were highest in winter and lowest in summer, and affected syconium contents positively across all seasons. Greater transpiration from the nurseries was possibly responsible for smaller syconia in summer. The 3–5°C increase in mean temperatures between the cooler seasons and summer reduced fig wasp reproduction and increased seed production nearly two-fold. Yet, seed and pollinator progeny production were never negatively related in any season confirming the mutualistic fig–pollinator association across seasons. Parasites affected seed production negatively in some seasons, but had a surprisingly positive relationship with pollinators in most seasons. While within-tree reproductive phenology did not vary across seasons, its effect on syconium inhabitants varied with season. In all seasons, within-tree reproductive asynchrony affected parasite reproduction negatively, whereas it had a positive effect on pollinator reproduction in winter and a negative effect in summer. Seasonally variable syconium volumes probably caused the differential effect of within-tree reproductive phenology on pollinator reproduction. Within-tree reproductive asynchrony itself was positively affected by intra-tree variation in syconium contents and volume, creating a unique feedback loop which varied across seasons. Therefore, nursery size affected fig wasp reproduction, seed production and within-tree reproductive phenology via the feedback cycle in this system. Climatic factors affecting plant reproductive traits can cause biotic relationships between plants, mutualists and parasites to vary seasonally and must be accorded greater attention, especially in the context of climate change.
476

Nouveau concept simplifié d’antennes reconfigurables utilisant les couplages interéléments : Mise en œuvre d’un réseau hybride / New simplified concept of reconfigurable antennas using the inter-element couplings : Implementation of a hybrid network

Oueslati, Aymen 17 December 2015 (has links)
Les travaux de cette thèse s’intéressent à un nouveau concept d’antenne reconfigurable offrant un bon compromis entre performances, complexité et coût. Ce concept, qualifié d’hybride, vise à combiner les avantages des réseaux d’antennes lacunaires et des antennes à éléments parasites. Cette hybridation est une alternative à la complexité des réseaux d’antennes conventionnels pour répondre aux exigences d’une architecture modulaire, générique et reconfigurable. L’intérêt majeur de ce concept est de proposer une architecture d’antenne permettant de réduire la complexité du circuit de formation des faisceaux (par la réduction du nombre d’éléments rayonnants à alimenter) tout en adressant les problématiques d’adaptation (TOS actif) des éléments excités. Ceci est permis grâce à la présence d’éléments parasites qui permettent de gérer la diffusion des couplages sur l’antenne. Cette thèse décrit le principe du concept hybride et propose une évaluation de ses potentialités. Par la suite, une définition des éléments à mettre en œuvre pour réaliser une preuve de concept est effectuée, en mettant l’accent sur l’importance de la caractérisation expérimentale. Les performances d’un prototype d’antenne hybride reconfigurable sont ensuite présentées afin de valider les développements et conclure sur cette solution innovante. / The work of this thesis aims to investigate a new concept of reconfigurable antenna allowing a good trade-off between performances, complexity and cost. This concept is called ‘hybrid’ because it is based on the capabilities of thinned arrays and parasitic element antennas. It is an alternative to classical antenna arrays and their complexity. The proposed concept has a modular architecture, and a good versatility for reconfigurable beams. The main advantage of this hybrid antenna is the simplicity of its beam formation network (BFN) which requires only a few number of excited elements. The antenna uses parasitic elements to manage the effects of couplings between the electromagnetic access. The problematic of active VSWR is also solved at the antenna level, avoiding the use of additional components in the BFN. This work details the principle of the reconfigurable hybrid antenna concept. The potentialities are evaluated. The elements required to realize a proof of concept are then defined, using a dedicated experimental setup. A prototype is manufactured and the performances have been checked to validate this innovative concept.
477

Modélisation et Conception des Composants Passifs Planar pour Filtres CEM / Modeling and Design of Passive Planar Components for EMI Filters

Tan, Wenhua 30 November 2012 (has links)
Les composants magnétiques en technologie planar répondent aux exigences actuelles de l’Electronique de Puissance (EP), à savoir la montée en fréquence de commutation des structures d’EP et la réduction du volume des convertisseurs. La première tendance impose des contraintes fortes en termes de compatibilité électromagnétique (CEM) des équipements. Ces dernières doivent être prises en compte par les ingénieurs dès la phase conception des convertisseurs en se basant sur des modèles fiables, peu développés pour les composants planar dans la littérature scientifique. Ce travail de thèse porte ainsi sur la modélisation des composants planar pour applications aux filtres CEM. Différentes méthodes sont développées au cours de cette thèse pour arriver à évaluer de manière fine les éléments parasites des inductances planar de mode commun : capacités parasites et inductances de fuite. Une partie du travail a porté sur la modélisation par circuits équivalents du comportement fréquentiel des inductances de MC. Une approche automatisée, basée sur un algorithme de fitting a ainsi été développée pour élaborer des circuits équivalents fiables et robustes. Des approches analytiques (Décomposition du Champ Electrique) et semi-analytiques (Fonctions de Green) ont aussi été proposées pour évaluer les valeurs des éléments parasites. La dernière partie de la thèse est plus orientée conception, avec la réalisation de deux structures de composants innovantes, la première se basant sur une technique de compensation des capacités parasites à l’aide d’éléments parasites structuraux et la seconde sur l’association de deux noyaux magnétiques, possédant matériaux et géométries différentes / The magnetic components with planar technology join in the current trends in Power Electronics (PE), namely increasing the switching frequency of PE structures and reducing the size of the power converters. The first tendency imposes strong constraints in terms of electromagnetic compatibility of equipments. The latter has to be considered by engineers at the beginning of the design of Power converters on the basis of reliable models, which are not sufficiently developed for planar components in scientific literature. This PhD work thereby focuses on the modeling of planar components for the applications of EMI filters. Different methods are developed during this study in order to accurately evaluate the parasitic elements of planar common-mode chokes: parasitic capacitances and leakage inductances. A part of this dissertation concerns the equivalent circuit modeling of the frequency behavior of CM chokes. An automated approach, based on a fitting algorithm developed for elaborating reliable and robust equivalent circuits. Analytical approaches (Electric Field Decomposition) and semi-analytical (Green’s Function) are proposed as well for calculating the values of these parasitic elements. The last part of this dissertation is oriented to conception, with the realization of two structures of innovative components, the first one based on a parasitic capacitance cancellation technique using structural parasitic elements and the second one on the association of two magnetic cores with different materials and geometries
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Doenças de caprinos no centro-oeste do Brasil / Diseases in goats in the midwestern Brazil

Rosa, Fábio Brum 25 January 2017 (has links)
The data herein described is a compilation of retrospective and prospective studies of diseases in goats diagnosed at the Laboratório de Anatomia Patologica at the Universidade Federal de Mato Grosso do Sul. This investigation examined 74 necropsy reports of goats obtained for the period between January 2012 and August 2015. The results yielded 72 conclusive diagnoses (in 6 cases there was more than one diagnosis by necropsy), and 16 it was not possible to conclude for a diagnosis.. Of the 72 conclusive diagnoses, 65.3% were infectious and parasitic diseases, 25.0% were intoxications and toxinfections, and 8.3% were metabolic and nutritional diseases. Other disorders were diagnosed on one occasion only (1.4%). Haemonchosis was the most prevalent condition in all diagnoses (27.8%), followed by bilateral bronchopneumonia (20.8%) and poisoning by Brachiaria decumbens (18.1%). Four scientific papers resulted from this study: (1) Spontaneous poisoning by Brachiaria decumbens in goats; (2) Renal encephalopathy due to acute renal failure in a goat; (3) Granulomatous leptomeningitis in a goat associated with infection by Cryptococcus neoformans and (4) Hepatogenous chronic copper toxicosis associated with grazing Brachiaria decumbens in a goat. These four papers are already published and attached to this thesis. / Esta tese envolveu o estudo retrospectivo e prospectivo de doenças de caprinos diagnosticadas no Laboratório de Anatomia Patológica da Universidade Federal de Mato Grosso do Sul. Para isso, foram examinados os laudos de necropsias de caprinos realizadas de Janeiro de 2012 a Agosto de 2015. Durante o período estudado foram realizadas necropsias de 74 caprinos, que resultaram em 72 diagnósticos conclusivos (em 6 necropsias houve mais de um diagnóstico) e em 16 não foi possível concluir por um diagnóstico. Do total de 72 diagnósticos conclusivos, 65,3% eram de doenças infecciosas e parasitárias, 25,0% eram de intoxicações e toxinfecções e 8,3% eram de doenças metabólicas e nutricionais. Outros distúrbios foram diagnosticados em menor proporção (1,4%). Hemoncose foi a condição mais prevalente sobre o total de diagnósticos (27,8%), seguida de broncopneumonia bilateral (20,8%) e de intoxicacao por Brachiaria decumbens (18,1%). Este estudo resultou em quatro trabalhos científicos: (1) Spontaneous poisoning by Brachiaria decumbens in goats; (2) Renal encephalopathy due to acute renal failure in a goat; (3) Granulomatous leptomeningitis in a goat associated with infection by Cryptococcus neoformans e (4) Hepatogenous chronic copper toxicosis associated with grazing Brachiaria decumbens in a goat. Esses quatros trabalhos já estão publicados e estão anexados a esta tese.
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Perfil nosológico da população ribeirinha do baixo rio Machado em Rondônia / Amazônia Ocidental - Brasil. / Nosology profile of riverine people from down Machado river in Rodônia / Western Amazon - Brazil.

Tiene Zingano Hinke 07 August 2009 (has links)
Foi estudado o perfil nosológico da população ribeirinha do Baixo Rio Machado em Rondônia, área de Amazônia Ocidental no Brasil. Neste estudo, escolhemos abordar o perfil das seguintes doenças: malária, hepatite viral B e C, parasitose intestinal e papilomavírus humano. Estas doenças foram priorizadas devido à importância clínica e epidemiológica e também escassez de estudos referentes nas populações ribeirinhas amazônicas. Para isto, foi realizado um estudo descritivo no Baixo Rio Machado que se localiza a 250 km de Porto Velho (capital do Estado de Rondônia) pela margem direita do Rio Madeira, que é um afluente volumoso do Rio Amazonas, no Brasil. Nesta área, vivem aproximadamente 806 pessoas distribuídas em 55 comunidades ribeirinhas isoladas. Em Rondônia, encontramos locais, como o Rio Machado, que abrigam a presença de portadores assintomáticos do Plasmodium, fato que pode contribuir para a persistência desta doença na região. Para caracterizar o perfil da malária ribeirinha, focalizando aspectos da infecção assintomática e sintomática, foram realizados hemoscopia e Reação em Cadeia da Polimerase (PCR) com amplificação do DNA ribossomal do parasita para Plasmodium vivax e Plasmodium falciparum para o diagnóstico da malária. Foi considerado como assintomático o paciente com hemoscopia positiva ou PCR positivo que permaneceu sem sintomas durante pelo menos 60 dias. Foi realizado acompanhamento longitudinal de 70 dias após o primeiro corte transversal (nC1=585 pessoas) para observação dos pacientes assintomáticos diagnosticados por hemoscopia, onde 25 pacientes (4,25%) permaneceram assintomáticos durante todo esse seguimento. Após, foi realizado mais dois cortes transversais a cada 6 meses (nC2=583 pessoas, nC3=607 pessoas), com tratamento dos indivíduos assintomáticos diagnosticados por PCR no corte transversal anterior ou hemoscopia atual e também dos casos sintomáticos. Foi estudado, na população que permaneceu na área durante toda a pesquisa (n=379), o perfil e o impacto do tratamento da infecção assintomática. Houve diminuição da infecção por P. falciparum de seis vezes e aumento da prevalência de malária por P. vivax de aproximadamente três vezes. O diagnóstico por PCR foi de 2-5 vezes mais eficiente do que por hemoscopia e a prevalência de infecção assintomática foi de 16 a 22% nos cortes transversais. Assim, foi observada a importância do tratamento dos indivíduos assintomáticos para o controle da malária no local, sendo que o incremento de malária por Plasmodium vivax deve ter ocorrido devido a recaídas da doença. Com o estudo entomológico da área, foi verificado que o vetor Anopheles possui atividade hematofágica moderada e principalmente em região peridomiciliar, sendo o A. darlingi a principal espécie da região. Existem poucos dados sobre a prevalência de hepatites na população ribeirinha de Rondônia, o que dificulta a vigilância epidemiológica nestas regiões amazônicas. Foi realizado um estudo de prevalência de hepatite B e C na área, com 123 pacientes pertencentes a 5 comunidades ribeirinhas, incluindo todas as pessoas que estavam presentes na área no momento do corte transversal, de todas as faixas etárias. Foi realizada sorologia para os marcadores de hepatite B: HbsAg, Anti-Hbc (total) e Anti-Hbs e sorologia para hepatite C com o marcador anti-HCV. Foram encontrados 12 (14,7%) pacientes com hepatite B aguda, 29 (38,7%) pacientes apresentaram imunidade vacinal para hepatite B e 7 (9,3%) pacientes apresentaram hepatite C, sendo que um (1,3%) paciente tinha co-infecção para hepatite B e C. Notou-se que esta população ribeirinha está exposta às hepatites virais, sendo necessário intensificar a vigilância epidemiológica na área, assim como a cobertura vacinal e também fornecer cuidados preventivos, curativos e paliativos em relação a estas doenças. A infecção pelo papilomavírus humano (HPV) é altamente prevalente, sendo detectada em aproximadamente 10% a 20% da população sexualmente ativa entre 15 e 49 anos de idade. A introdução de testes mais acurados para a detecção do DNA do HPV em investigações epidemiológicas confirmou a importância do HPV, principalmente dos tipos de alto risco, como o principal fator de risco para o desenvolvimento de neoplasia intra-epitelial cervical e câncer do colo uterino. Não foram encontrados estudos sobre a existência do HPV em populações ribeirinhas amazônicas na literatura médica. Foi realizado, então, um estudo transversal para levantar a prevalência de HPV nesta população, com 84 participantes em idade sexualmente ativa presentes na área. Após coleta de consentimento informado e questionário clínico-epidemiológico, foi realizado exame para isolar o HPV. A tipagem do HPV foi realizada com amplificação dos DNAs por PCR empregando iniciadores genéricos seguida de hibridização em pontos, capaz de identificar mais de 40 tipos diferentes de HPVs. Foram encontradas 18 pacientes contaminadas pelo HPV, perfazendo 21,4% da amostra. Os tipos de HPV encontrados foram: 53, 58, 31, 56, 16, 83, 55, 66, 45, 51, 40, 42, 6, 68. Os tipos de HPV mais freqüentes foram 51 (23%), 58 (19%), 53 (7,7%), 83 (7,7%), sendo HPV 16 encontrado em 3,8% das pacientes HPV positivas e a prevalência do HPV de alto risco oncogênco foi de 13,1%. Desta forma, foi encontrado alta prevalência de HPV na população ribeirinha amazônica estudada, evidenciando a necessidade de vigilância epidemiológica para câncer de colo uterino na região. Por fim, foi estabelecido a prevalência de parasitoses intestinais na população, abordando a correlação das enteroparasitoses com malária assintomática e anemia, realizando um inquérito coproparasitológico na área incluindo pacientes de todas as faixas etárias, que estivessem dispostos a participar do estudo. A análise das amostras foi realizada pelo método da Sedimentação Espontânea (método de Lutz ou Hoffmann, Pons & Janer). Entre os 268 exames de fezes realizados, a prevalência de parasitose intestinal encontrada na região em estudo foi de 86,6%. Entre os helmintos, Ascaris lumbricoides (47%), Ancilostomideos (37,3%), Trichuris trichiura (3,4%), Capillaria hepatica (2,3%), foram os parasitas mais encontrados. Entre os protozoários foram encontrados: Entamoeba coli (21,4%), Entamoeba histolytica (12%), Giardia intestinalis (15,4%), Endolimax nana (10,1%) e Iodamoeba butschlii (7,5%). A alta prevalência de parasitose intestinal encontrada na pesquisa foi concordante com outros dados desenvolvidos na Região Amazônica. Com este estudo, a região da Amazônia Ocidental insere-se no cenário geográfico mundial de distribuição da Capillaria hepatica, particularmente, a região do Baixo Rio Machado. / Was studied the nosological profile of the riverside population of the Baixo Rio Machado in Rondônia, Western Amazon area of Brazil. In this study, was chosed the profile of following diseases: malaria, hepatitis B and C, intestinal parasite and human papillomavirus. These diseases have been prioritized due to clinical and epidemiological importance and scarcity of studies in the riverside Amazon population. For this, was conducted a descriptive study in the Baixo Rio Machado which is located 250 km from Porto Velho (capital of Rondônia State) in the right bank of the Rio Madeira which is a large tributary of the Amazon River in Brazil. In this area, live about 806 people distributed in 55 riversides communities isolated. In Rondônia, we find places such as the Rio Machado, which shelter to the presence of asymptomatic carriers of Plasmodium, which may contribute to the persistence of this disease in the region. To characterize the profile of malaria riverside, focusing on aspects of symptomatic and asymptomatic infections, were performed haemoscopia and Polymerase Chain Reaction (PCR) with amplification of ribosomal DNA for the parasite Plasmodium vivax and Plasmodium falciparum to the diagnosis of malaria. Was considered as asymptomatic patient with positive haemoscopia or positive or PCR that remained without symptoms for at least 60 days. Longitudinal follow-up was conducted for 70 days after the first cross section (nC1 = 585 people) for observation of asymptomatic patients diagnosed by haemoscopia where 25 patients (4.25%) remained asymptomatic throughout the follow-up. After was performed two cross cuts every 6 months (nC2 = 583 people, nC3 = 607 people), with treatment of asymptomatic individuals diagnosed by PCR in previous transverse cross-sections or haemoscopia a current and also symptomatic cases. We studied in the population that remained in the area throughout the study (no= 379), the profile and impact of treatment of asymptomatic infection. There was a decrease in infection by P. falciparum of six times and increased prevalence of malaria by P. vivax approximately three times. The diagnosis by PCR was 2-5 times more efficient than haemoscopia and the prevalence of asymptomatic infection was 16 to 22% in transverse cross-sections. Thus, was saw the importance of treatment of asymptomatic individuals for the control of malaria in the place, and the increase in malaria by Plasmodium vivax should have occurred due to relapse of the disease. With entomological study of the area, was saw that the vector Anopheles has moderate blood activity and especially in peridomiciliary region and the A. darlingi the main species in the region. There are few data on the prevalence of hepatitis in riverside population of Rondônia, which makes surveillance in Amazonian regions. Was conducted a study of prevalence of hepatitis B and C in the area, with 123 patients belonging to 5 communities, including all the people who were present in the area at the cross section of all ages. Serology was performed for markers of hepatitis B: HBsAg, anti-HBc (total) and anti-HBs and serology for hepatitis C with anti-HCV marker. Was found 12 (14.7%) patients with acute hepatitis B, 29(38.7%) patients demonstrated immunity to hepatitis B vaccine and 7(9.3%) patients had hepatitis C, with one (1.3%) patient had co-infection for hepatitis B and C. Realize that this riverside population is exposed to viral hepatitis, being necessary to intensify epidemiological surveillance in the area, as well as immunization coverage and provide preventive care, curative and palliative for these diseases. The infection by human papillomavirus (HPV) is highly prevalent, being detected in approximately 10% to 20% of the sexually active population between 15 and 49 years of age. The introduction of more accurate tests for the detection of HPV DNA in epidemiological investigations confirmed the importance of HPV, particularly types of high risk, as the main risk factor for the development of cervical intraepithelial neoplasia and cervical cancer. Was found no studies on the existence of HPV in riverside Amazonian populations in the medical literature. The transversal cross-section study was take up to raise the prevalence of HPV in this population, with 84 participants in sexually active age in the area. After collection of informed consent and clinical-epidemiological questionnaire, was conducted to isolate the HPV test. The typing of HPV was taking with the DNAs for PCR using generic primers followed by hybridization in points, able to identify over 40 different types of HPV. Was found 18 patients infected by HPV, comprising 21.4% of the sample. The HPV types found were: 53, 58, 31, 56, 16, 83, 55, 66, 45, 51, 40, 42, 6, 68. The most common HPV types were 51 (23%), 58 (19%), 53 (7.7%), 83 (7.7%) with HPV 16 found in 3.8% of HPV positive patients and prevalence the high risk HPV oncogenic was 13.1%. Thus, was find high prevalence of HPV in riverside Amazonian population studied, highlighting the need for surveillance for cancer of the cervix in the region. Finally, was established the prevalence of intestinal parasites in the population, deal the correlation of intestinal with asymptomatic malaria and anemia, taking the fecal examination conducting in the area including patients of all ages, who were willing to participate in the study. The analysis of samples was performed by the spontaneous sedimentation method (method of Lutz or Hoffmann, Pons & Janer). Among the 268 fecal examinations, the prevalence of intestinal parasite found in the region under study was 86.6%. Among helminths, Ascaris lumbricoides (47%), Ancilostomideos (37.3%), Trichuris trichiura (3.4%), Capillaria hepatica (2.3%) were found more parasites. Among the protozoa were: Entamoeba coli (21.4%), Entamoeba histolytica (12%), Giardia intestinalis (15.4%), Endolimax nana (10.1%) and Iodamoeba butschlii (7.5%).The high prevalence of intestinal parasite found in the survey was consistent with other data developed in the Amazon region. In this study, the region of the Western Amazon is part of the scenario of global geographic distribution of Capillaria hepatica, particularly the region of the Baixo Rio Machado.
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RC oscilátory pro pásmo vyšších kmitočtů / Oscillators RC for higher frequency range

Polách, Petr January 2008 (has links)
This thesis deals with RC oscillators applicable in higher frequency ranges with the use of modern active elements. For individual function blocks (conveyor, current feedback amplifier, operational transconductance amplifier, voltage feedback amplifier) suitable models are suggested for the circuit simulator PSpice covering their characteristics on various levels, from an ideal one up to the full description of parasitic effects. On the basis of the study of recommended literature and company documentation various oscillator connections of the ranks 2 and 3 are suggested. By analysis through computer (PSpice, SNAP) the fulfilment of oscillation conditions, onset of oscillations were verified and by means of suitable simulations the effects of the impact on the parasitic characteristics of active elements was examined. Finally there are two oscillator connections stated and verified by simulations with the possibility of electronic retuning.

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