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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.
191

Avaliação do mecanismo de quorum sensing entre lactobacillus spp. Contra salmonella heidelberg em frangos de corte.

Moraes, Ana Carolina Izidoro de. January 2019 (has links)
Orientador: Adriano Sakai Okamoto / Resumo: Uma das principias doenças transmitida por alimento é a salmonelose, causada pela bactéria Salmonella spp., ela está presente em vários aviários, e com o aumento da produção avícola, se disseminou nos aviários, tornando-se um problema pertinente e de grande importância na saúde pública e animal. Com isso medidas de controle foram instituídas, entre elas o uso de antimicrobiano, causando diversas discussões, principalmente em relação a resistência bacteriana á antimicrobianos utilizados na medicina humana, onde medidas alternativas estão sendo desenvolvidas para evitar o uso dos antimicrobianos. Dessa forma o objetivo do projeto foi avaliar a capacidade dos Lactobacillus spp., isolados na inibição da Salmonella Heidelberg (SH), pelo mecanismo de quorum sensing in vitro e in vivo. Foram colhidos de suabes cloacal de frangos de corte que passaram por provas fenotípica e molecular. Esses isolados foram submetidos ao teste de inibição em placa para avaliar a capacidade de inibição da SH. Em seguida foram produzidos os filtrados, a partir dos Lactobacillus sp. (ATCC), separadamente, com contato com a SH. Esses isolados foram cultivados com os filtrados, separadamente e em seguida submetidos novamente ao teste de inibição em placa. Dessa maneira, foi possível medir e comparar os halos de inibição, para a verificação da ocorrência da comunicação bacteriana entre os Lactobacillus sp. (ATCC) e os isolados. Foi realizada a análise estatística selecionando um Lactobacillus spp. isolado d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: One of the main food-borne diseases is salmonellosis, caused by the bacterium Salmonella spp., It is present in several aviaries, and with the increase of poultry production, it has spread in aviaries, becoming a relevant problem and of great importance in health public and animal. With this, control measures were instituted, including the use of antimicrobial, causing several discussions, mainly regarding bacterial resistance to antimicrobials used in human medicine, where alternative measures are being developed to avoid the use of antimicrobials. Thus, the objective of the project was to evaluate the ability of Lactobacillus spp., isolated in the inhibition of Salmonella Heidelberg (SH), by in vitro and in vivo quorum sensing mechanism. They were harvested from cloacal swabs of chickens that underwent phenotypic and molecular tests. These isolates were subjected to plaque inhibition test to assess the inhibitory capacity of SH. Filtrates were then produced from Lactobacillus sp. (ATCC), separately, with SH. These isolates were cultured with the filtrates separately and then replate inhibited. In this way, it was possible to measure and compare inhibition halos to verify the occurrence of bacterial communication between Lactobacillus sp. (ATCC) and the isolates. Statistical analysis was performed by selecting a Lactobacillus spp. isolated from chickens and a filtrate which obtained better results in the in vitro test. The in vivo test was divided into four treatments, Lacto... (Complete abstract click electronic access below) / Mestre
192

Automação do monitoramento da qualidade do processo de solda a ponto resistiva. / Automatic quality monitoring of resistance spot welding process.

Sampaio, Daniel Julien Barros da Silva 30 April 2010 (has links)
Neste trabalho é proposto e avaliado um sistema capaz de monitorar de forma não-destrutiva, não-invasiva, individualizada, em tempo real e em ambiente industrial, a qualidade de soldas produzidas através do processo de solda a ponto resistiva (PSPR), diminuindo ou mesmo eliminando a necessidade dos testes destrutivos, reduzindo custos e aumentando a produtividade. Este sistema de monitoramento é baseado em reconhecimento de padrões, através de redes neurais artificiais do tipo Perceptron multicamadas. As características do processo usadas na entrada da rede neural são os parâmetros ajustados de um modelo matemático parametrizável, criado com o intuito de refletir as propriedades fundamentais da grandeza do processo passível de ser medida e monitorada em tempo real, neste caso a curva de resistência dinâmica. Estes valores ajustados dos parâmetros do modelo são ainda relacionados com os estados ou condições do processo, de forma a permitir a identificação de possíveis causas para falhas detectadas. Para avaliar e validar este sistema, usaram-se dados reais obtidos na produção de lotes de contatos elétricos através do PSPR. Os resultados obtidos mostram que o sistema proposto é capaz de monitorar satisfatoriamente a qualidade do processo investigado, com erro médio quadrático de 16,5 N, na estimação da força de cisalhamento suportada pela solda, no pior caso. O sistema também mostrou-se capaz de identificar a causa para soldas cuja qualidade estimada foi considerada baixa, com taxa de acerto acima de 97%. Esse sistema proposto não contém especificidades de nenhum processo produtivo e, portanto, tem potencial para ser aplicado em outros processos, além do PSPR. / In this work a non-destructive, non-invasive, individualized, real-time system has been proposed and evaluated to monitor the quality of welds produced by resistance spot welding process (RSWP) in industrial environment. This system is able to reduce or eliminate the need for destructive tests, leading to cost reduction and increase in productivity. This monitoring system is based on pattern recognition with multilayer Perceptron artificial neural networks (ANN). The process features used as input of the ANN are adjusted parameters of a parametric mathematic model created to reflect the fundamental properties of the process variable that is measurable in real time, in this work, the dynamic resistance curve. The adjustable model parameters values are related with the process states and conditions, so that it is possible to identify the causes for detected bad quality. In order to evaluate and validate the proposed system, real data obtained in the production of electric contacts by RSWP were used. The results show that the proposed system is capable of properly monitoring the investigated process quality, with a mean square error of 16.5 N, in the estimation of the shear force supported by the weld, in the worst case. The system proved to be able to identify the causes for detected bad quality, with a reliability of more than 97%. The proposed system contains no productive process specificities, and, therefore, can be applied to other processes.
193

"A influência da mancha cega na percepção de tamanho linear". / The influence of blind spot on linear size perception

Mendes, Ana Irene Fonseca 11 July 2001 (has links)
Em três experimentos realizou-se o mapeamento da mancha cega do olho direito para se investigar se o completamento perceptivo que ocorre nela distorce a percepção de tamanho de barras. Em todos os experimentos, o mapeamento da mancha cega foi realizada pelo método dos estímulos constantes; os tamanhos das barras podiam nunca interceptar a mancha cega, interceptá-la parcialmente ou interceptá-la por completo; e as barras eram apresentadas pelo método PEST para se determinar o ponto de igualdade subjetiva, e conseqüentemente, o erro constante. No Experimento I as barras eram horizontais e comparadas no nível do ponto de fixação em condição monocular com o olho direito. Elas eram apresentadas por 100, 300 ou 400 ms, aos pares, simultânea e simetricamente localizadas no hemicampo direito e esquerdo em relação ao ponto de fixação. Os resultados desse experimento indicaram uma assimetria lateral nas comparações de tamanho da barra menor e que o completamento perceptivo na mancha cega não distorce efetivamente o tamanho percebido. No Experimento II as barras eram verticais e podiam ser apresentadas também por 100, 300 ou 400 ms, aos pares, simultânea e simetricamente em relação ao ponto de fixação em cinco excentricidades nos hemicampos do olho direito em condição monocular. As barras nas excentricidades menor e maior não interceptavam a mancha cega e as barras de tamanhos maior e intermediário nas excentricidades intermediárias incidiam nas regiões periféricas e central da mancha cega. Os resultados indicaram também que o completamento perceptivo na mancha cega não distorce a percepção de tamanho e que em algumas excentricidades em que a barra padrão foi apresentada no hemicampo esquerdo evidencia-se uma assimetria lateral na comparação de tamanhos. No experimento III, o mapeamento da mancha cega do olho direito e as comparações das barras verticais foram realizados em condição dicótica. As barras foram apresentadas aos pares e seqüencialmente, expostas por 100 ms cada e com um intervalo de 200 ms entre suas apresentações. Elas foram apresentadas em cinco excentricidades no hemicampo direito de cada olho, similar ao Experimento II, de maneira que as comparações de tamanho envolvessem somente o hemisfério cerebral esquerdo. Os resultados indicaram também que o completamento perceptivo na mancha cega não distorce o tamanho percebido. Os três experimentos sugerem que existe assimetria ao se comparar tamanhos, embora tênue, quando se envolvem ambos hemisférios cerebrais e que a explicação associativa proposta por Trypathy et al. (1995) é a alternativa que melhor explica o completamento perceptivo na mancha cega. / Three experiments were carried out to investigate whether the filling-in in the blind spot can distort perceived size. In these experiments, the method of constant stimuli was applied to map the blind spot of the right eye; the lengths of the bars could never intercept the blind spot, intercept it partially or intercept it totally; and the PEST method was applied to determine the point of subjective equality, and then, the constant error. In Experiment I, the lengths of two horizontal bars were compared at the level of fixation point of the right eye under monocular viewing conditions. These bars were presented simultaneously for 100, 300 or 400ms and they were located symmetrically to each other from the fixation point. Results suggested that the filling-in in the blind spot did not distort perceived length, and that there was lateral asymmetry in comparing bars which lengths do not intercept the blind spot. In Experiment II, two vertical bars were presented simultaneously also for 100, 300 or 400ms and symmetrically from the fixation point at five eccentricities in the visual hemifields of right eye in monocular viewing conditions. Bars at the farther and closest eccentricity never intercepted the blind spot, and the bars at intermediate eccentricities could intercept the central and peripheral regions of the blind spot. Results also indicated that the filling-in in the blind spot did not distort perceived size, and that there was lateral asymmetry in comparing size as the standard bar was at the left visual hemifield. In Experiment III, the blind spot of the right eye was mapped and length bar comparisons were done in dichotic conditions in such way that only the left brain was involved. Two vertical bars were presented at five eccentricities like in Experiment II, but they were presented sequentially for 200 ms with an interval of 400 ms between presentations. Results also indicated that the filling-in did not affect perceived size. These three experiments suggest that there is a weak lateral asymmetry in size comparisons due to the inter-hemispheric brain effect and that the associative explanation proposed by Trypathy et al. (1995) is the best alternative to explain the filling-in in the blind spot.
194

"A influência da mancha cega na percepção de tamanho linear". / The influence of blind spot on linear size perception

Ana Irene Fonseca Mendes 11 July 2001 (has links)
Em três experimentos realizou-se o mapeamento da mancha cega do olho direito para se investigar se o completamento perceptivo que ocorre nela distorce a percepção de tamanho de barras. Em todos os experimentos, o mapeamento da mancha cega foi realizada pelo método dos estímulos constantes; os tamanhos das barras podiam nunca interceptar a mancha cega, interceptá-la parcialmente ou interceptá-la por completo; e as barras eram apresentadas pelo método PEST para se determinar o ponto de igualdade subjetiva, e conseqüentemente, o erro constante. No Experimento I as barras eram horizontais e comparadas no nível do ponto de fixação em condição monocular com o olho direito. Elas eram apresentadas por 100, 300 ou 400 ms, aos pares, simultânea e simetricamente localizadas no hemicampo direito e esquerdo em relação ao ponto de fixação. Os resultados desse experimento indicaram uma assimetria lateral nas comparações de tamanho da barra menor e que o completamento perceptivo na mancha cega não distorce efetivamente o tamanho percebido. No Experimento II as barras eram verticais e podiam ser apresentadas também por 100, 300 ou 400 ms, aos pares, simultânea e simetricamente em relação ao ponto de fixação em cinco excentricidades nos hemicampos do olho direito em condição monocular. As barras nas excentricidades menor e maior não interceptavam a mancha cega e as barras de tamanhos maior e intermediário nas excentricidades intermediárias incidiam nas regiões periféricas e central da mancha cega. Os resultados indicaram também que o completamento perceptivo na mancha cega não distorce a percepção de tamanho e que em algumas excentricidades em que a barra padrão foi apresentada no hemicampo esquerdo evidencia-se uma assimetria lateral na comparação de tamanhos. No experimento III, o mapeamento da mancha cega do olho direito e as comparações das barras verticais foram realizados em condição dicótica. As barras foram apresentadas aos pares e seqüencialmente, expostas por 100 ms cada e com um intervalo de 200 ms entre suas apresentações. Elas foram apresentadas em cinco excentricidades no hemicampo direito de cada olho, similar ao Experimento II, de maneira que as comparações de tamanho envolvessem somente o hemisfério cerebral esquerdo. Os resultados indicaram também que o completamento perceptivo na mancha cega não distorce o tamanho percebido. Os três experimentos sugerem que existe assimetria ao se comparar tamanhos, embora tênue, quando se envolvem ambos hemisférios cerebrais e que a explicação associativa proposta por Trypathy et al. (1995) é a alternativa que melhor explica o completamento perceptivo na mancha cega. / Three experiments were carried out to investigate whether the filling-in in the blind spot can distort perceived size. In these experiments, the method of constant stimuli was applied to map the blind spot of the right eye; the lengths of the bars could never intercept the blind spot, intercept it partially or intercept it totally; and the PEST method was applied to determine the point of subjective equality, and then, the constant error. In Experiment I, the lengths of two horizontal bars were compared at the level of fixation point of the right eye under monocular viewing conditions. These bars were presented simultaneously for 100, 300 or 400ms and they were located symmetrically to each other from the fixation point. Results suggested that the filling-in in the blind spot did not distort perceived length, and that there was lateral asymmetry in comparing bars which lengths do not intercept the blind spot. In Experiment II, two vertical bars were presented simultaneously also for 100, 300 or 400ms and symmetrically from the fixation point at five eccentricities in the visual hemifields of right eye in monocular viewing conditions. Bars at the farther and closest eccentricity never intercepted the blind spot, and the bars at intermediate eccentricities could intercept the central and peripheral regions of the blind spot. Results also indicated that the filling-in in the blind spot did not distort perceived size, and that there was lateral asymmetry in comparing size as the standard bar was at the left visual hemifield. In Experiment III, the blind spot of the right eye was mapped and length bar comparisons were done in dichotic conditions in such way that only the left brain was involved. Two vertical bars were presented at five eccentricities like in Experiment II, but they were presented sequentially for 200 ms with an interval of 400 ms between presentations. Results also indicated that the filling-in did not affect perceived size. These three experiments suggest that there is a weak lateral asymmetry in size comparisons due to the inter-hemispheric brain effect and that the associative explanation proposed by Trypathy et al. (1995) is the best alternative to explain the filling-in in the blind spot.
195

Development of a radiopaque infiltration resin for early enamel carious lesion

Moeinian, Malihe January 2018 (has links)
A white spot lesion (WSL) is defined as enamel porosity, which could be due to an enamel defect or an initial carious lesion. ICON® resin is a resin infiltrant that penetrates into the enamel porosity and seals the lesion, thus inhibiting the progression of caries. This method is micro-invasive; however, the resin is radiolucent and the clinician cannot detect the material using radiographs. In order to develop a radiopaque resin, understanding the pore size and pore structure in WSLs is helpful. Therefore, the aim of this study was to characterise: (1) the pore size and structure, (2) the incorporation of radiopaque agents into ICON® resin. Brunauer-Emmett-Teller (BET) and focused ion beam-scanning electron microscopy (FIB-SEM) were used to characterise the porosity in WSLs. The data showed the enamel prisms become more pronounced in the advanced areas of the WSLs and demineralisation occurs within or/and between the enamel prisms. The pore size could be as small as an enamel crystallite, 28x48nm. Nano-strontium hydroxyapatite (non-coated and coated) and strontium bioglass were made as radiopaque fillers and characterised using different techniques including fourier transform infrared spectroscopy (FTIR), BET, transmission electron microscopy (TEM), X-ray diffraction (XRD) and particle size measurements. The radiopaque fillers had micron-sized particles, which made them unsuitable for infiltration into WSLs despite their possible ability to remineralise the WSLs. Radiopaque monomers including bromine-methacrylate and tin-methacrylate were able to make ICON® resin radiopaque and they showed a similar viscosity, wettability and biocompatibility compared to ICON® resin. The X-ray microtomography (XMT) showed that the experimental radiopaque resins were able to infiltrate into the WSLs, artificial and natural lesions, and they could be detected using image subtraction. Backscattered electron (BSE) imaging after each step of application of materials showed that the etching pattern and etchant gel could be barriers for a successful infiltration of the resins into WSLs.
196

Controlling interfacial reaction in aluminium to steel dissimilar metal welding

Xu, Lei January 2016 (has links)
Two different aluminium alloys, AA6111 (Al-Mg-Si) and AA7055 (Al-Mg-Zn), were chosen as the aluminium alloys to be welded with DC04, and two welding methods (USW and FSSW) were selected to prepare the welds. Selected pre-welded joints were then annealed at T=400 - 570oC for different times. Kinetics growth data was collected from the microstructure results, and the growth behaviour of the IMC layer was found to fit the parabolic growth law. A grain growth model was built to predict the grain size as a function of annealing time. A double-IMC phase diffusion model was applied, together with grain growth model, to predict the thickness of each phase as a function of annealing time in the diffusion process during heat treatment. In both material combinations and with both welding processes a similar sequence of IMC phase formation was observed during the solid state welding. η-Fe2Al5 was found to be the first IMC phase to nucleate. The IMC islands then spread to form a continuous layer in both material combinations. With longer welding times a second IMC phase, θ-FeAl3, was seen to develop on the aluminium side of the joints. Higher fracture energy was received in the DC04-AA6111 joints than in the DC04-AA7055 joints. Two reasons were claimed according to the microstructure in the two joints. The thicker IMC layers were observed in the DC04-AA7055 joints either before or after heat treatment, due to the faster growth rate of the θ phase. In addition, pores were left in the aluminium side near the interface as a result of the low melting point of AA7055.The modelling results for both the diffusion model and grain growth model fitted very well with the data from the static heat treatment. Grain growth occurred in both phases in the heat treatment significantly, and was found to affect the calculated activation energy by the grain boundary diffusion. At lower temperatures in the phases with a smaller grain size, the grain boundary diffusion had a more significant influence on the growth rate of the IMC phases. The activation energies for the grain boundary diffusion and lattice diffusion were calculated as 240 kJ/mol and 120 kJ/mol for the η phase, and 220 kJ/mol and 110 kJ/mol for the θ phase, respectively. The model was invalid for the growth of the discontinuous IMC layers in USW process. The diffusion model only worked for 1-Dimensional growth of a continuous layer, which was the growth behaviour of the IMC layer during heat treatment. However, due to the highly transient conditions in USW process, the IMC phases were not continuous and uniform even after a welding time of 2 seconds. Therefore, the growth of the island shaped IMC particles in USW was difficult to be predicted, unless the nucleation stage was taken into consideration.
197

Finite element modelling of ventilated brake disc hot spotting

Tang, Jinghan January 2017 (has links)
Hot spotting of automotive disc brakes is an undesired thermal localisation phenomenon, which is a challenge for numerical modelling in terms of both accuracy and efficiency especially for complex disc geometry. In this research, the aim was to develop a computationally efficient finite element (FE) approach for 2-piece pin-mounted ventilated disc hot spot prediction with acceptable accuracy enabling parametric studies to contribute to the knowledge of the complex mechanisms. A time reduction strategy for the simulations was established by incorporating an axisymmetric brake pad assumption with material scaling factor and the friction characteristics were defined by a user-subroutine. The computing accuracy and efficiency of this method were then verified by comparing with traditional FE models. 2D in-plane, 2D out-of-plane, and 3D models were performed to investigate the effects of ventilated disc hot spotting, radial hot spot/band migration, and hot spotting of realistic complex disc geometry respectively. Both 2D and 3D results were validated using experimental results based on a laboratory dynamometer and showed good correlation. The results suggested that adequate modelling of friction pair contact pressure distribution and the subsequent non-uniform heat generation is essential for hot spot simulation; speed was identified as the determinant for the number of hot spots, whereas hot spot temperature was determined by energy level. Furthermore, recommendations for vent design, pins, disc run-out, cooling, material selection, wear rate, pad length and loading distribution were given. Finally, hot spotting and hot band migration cause-effect chains were established based on the results and discussion.
198

Inventory and procurement management in the presence of spot markets. / CUHK electronic theses & dissertations collection

January 2009 (has links)
In the first model, we study the optimal procurement strategy in a two-period framework when both the spot market and the forward contract are considered. The forward contract is agreed upon in the first period, and is then delivered in the second period, when the spot market is also available. This is followed by production and demand. The objective of the buyer is to minimize his expected cost. We study the problem for two scenarios: the buyer cannot and can sell to the spot market. Through our analysis, when the buyer can not sell to the spot market, there exists a threshold forward price, under which the buyer will enter into the forward contract. This threshold is lower than the expected spot price. Furthermore, we analytically show that the optimal order quantities via forward contract increase in the mean of the spot price, but decrease in the variability of the spot price. However, the buyer only speculates using the forward contract when he can sell to spot market. / In the second model, we consider a problem in which a buyer makes procurement decisions when he faces periodic random demand and two supply sources, one is a long-term contract supplier and the other is a spot market. When he procures from the contract supplier, a fixed unit price is charged and a predetermined minimum quantity for each period must be committed, and when he procures from the spot market, a stochastic spot price plus a fixed setup cost is charged. The spot price is only realized at the beginning of each period. We show that the optimal policy consists three different (s, S) type policies. More important, we identify certain conditions under which there exist monotone properties between the policy parameters and the current spot price for a general Markov spot price process. Then, we can divide the price space into three regions, each of which corresponds to a specific policy, for each period. We also conduct numerical analysis to gain more insights into how the spot market impacts the buyer's performance. We find the buyers benefits from a more volatile market. / The last model extends the second model by incorporating an important feature that is widely seen; i.e., the procurement from the contract supplier should fulfill a total order quantity commitment (TOQC). The TOQC requires the buyer to procure no less than the predetermined commitment during the contract period, which we call the planning horizon. Thus, in each period, the buyer trades off between the possible lower cost now (by procuring from the spot market) and the reduced cost in the future (by reducing the remaining commitment). Two types of commitment contracts are considered: a minimal TOQC contract and a definite quantity contract. Our analysis characterizes an optimal procurement policy which depends on the spot price in each period and an optimal virtual remaining commitment level. Such a structured policy can be viewed as a combination of some policies of base-stock type, each of which can be computed through an equivalent system without any commitment. Moreover, some of these equivalent systems are of simple multiple-period newsvendor type. This greatly simplifies the computation of the optimal policies. We also numerically analyze how the TOQC and the spot market affects the buyer's performance. / This research develops mathematical models for inventory and procurement management in the presence of spot markets. More specifically, we consider those models by incorporating different types of supply contracts. Particular attention is paid to the quantity flexible contracts. This research is an attempt to understand how firms should adopt their operating policies in the presence of fluctuating commodity prices. In this thesis, we mainly consider the following three models. / Xue, Weili. / Adviser: Youhua Chen. / Source: Dissertation Abstracts International, Volume: 72-11, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 122-134). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
199

Elaboração e validação de escalas diagramáticas para quantificação da severidade da mancha parda da mandioca e sazonalidade da doença no agreste meridional de Pernambuco

LIMA FILHO, Francisco Alberto de Sousa 29 July 2016 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-03-07T12:48:04Z No. of bitstreams: 1 Francisco Alberto de Sousa Lima Filho.pdf: 1454767 bytes, checksum: 0054a45daadb72e9247013cb331f0853 (MD5) / Made available in DSpace on 2017-03-07T12:48:04Z (GMT). No. of bitstreams: 1 Francisco Alberto de Sousa Lima Filho.pdf: 1454767 bytes, checksum: 0054a45daadb72e9247013cb331f0853 (MD5) Previous issue date: 2016-07-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Cassava (Manihot esculenta Crantz) plays an important role in human food. Among the diseases affecting this crop, the brown spot, caused by the fungus Passalora henningsii (Allesch.) R. F. Castañeda & U. Braun, is one the main diseases. The high intensity of this leaf spot, observed in the state of Pernambuco, together with the scarcity of information, demonstrate the need of further studies on this disease. Thus, the objectives of this research were: i) to develop, validate and verify the applicability of two diagrammatic scales to quantify the severity of brown spot on leaves and leaflets of cassava; ii) to study the epidemy of the disease in different areas in the Pernambuco state. To elaborate the diagrammatic scales, cassava leaves showing symptoms of the disease were scanned and the severity value was calculated using the Assess software. Two scales were developed, one to leaves and another to leaflets, each containing eight levels of severity (0.1; 0.6; 1.5; 3.0; 6.0; 11.0; 16.0 and 24.0%). The diagrammatic scales were validated by untrained evaluators, and both produced more accurate and precise estimates of the severity of brown spot of cassava. To assess the seasonality of brown spot in the Pernambuco state, 12 areas of commercial cultivation were selected during the season 2015/2016. The incidence was evaluated by counting the number of diseased leaves and the severity was measured with the aid of diagrammatic scale previously elaborated. This study showed that the disease occurs in all areas evaluated in the Pernambuco state, being mainly related to precipitation. Furthermore, it was found that some cultivars were more susceptible to disease. / A mandioca (Manihot esculenta Crantz) apresenta um importante papel na alimentação humana e animal, sendo a sexta cultura de maior produção no mundo. Dentre os problemas que afetam a cultura, destacam-se as manchas foliares, principalmente a mancha parda (MP), causada pelo fungo Passalora henningsii (Allesch.) R.F. Castañeda & U. Braun. A alta intensidade desta mancha foliar, observada no estado de Pernambuco, aliada à escassez de informações, demonstram a necessidade de estudos mais aprofundados acerca desta doença. Diante disso, os objetivos desta pesquisa foram: i) desenvolver, validar e verificar a aplicabilidade de duas escalas diagramáticas para quantificação da severidade da mancha parda em folhas e folíolos de mandioca; ii) estudar a epidemia da doença em diferentes áreas no Agreste de Pernambuco. Para elaborar as escalas diagramáticas, folhas de mandioca apresentando sintomas da doença foram digitalizadas e o valor de severidade calculado utilizando o software Assess. Foram desenvolvidas duas escalas, sendo uma para o folíolo central e outra para folha composta, cada uma contendo oito níveis de severidade (0,1; 0,6; 1,5; 3,0; 6,0; 11,0; 16,0 e 24,0%). As escalas foram validadas por avaliadores inexperientes, e verificou-se que ambas propiciaram estimativas mais acuradas e precisas da severidade da mancha parda. Para avaliar a sazonalidade da MP no Agreste de Pernambuco, foram selecionadas 12 áreas de cultivo comercial de mandioca durante a safra 2015/2016. A incidência foi avaliada pela contagem do número de folhas doentes e a severidade foi medida com o auxílio da escala de folha composta previamente elaborada. Este estudo mostrou que a doença ocorre em todas as áreas avaliadas no Agreste Meridional, estando relacionada principalmente com a precipitação. Além disso, foi verificado que algumas cultivares apresentam-se mais suscetíveis ao ataque do patógeno.
200

Caracterização do antígeno-5, alérgeno do veneno da vespa social Polybia paulista com uma abordagem proteômica /

Pinto, José Roberto Aparecido dos Santos. January 2011 (has links)
Resumo: Os venenos dos insetos da ordem Hymenoptera contêm uma variedade de proteínas alergênicas. As ferroadas desses insetos podem induzir reações alérgicas e ocasionalmente, anafilaxias fatais. Há um crescente interesse nos componentes químicos dos venenos desses insetos, sobretudo no campo da alergia e imunologia clínica. As principais reações desses venenos são as reações inflamatórias e/ou imunológicas em suas vítimas, podendo ocorrer alguns efeitos sistêmicos. Dentre os Hymenoptera sociais, os venenos de abelhas e vespas têm sido extensivamente estudados e muitos de seus componentes moleculares já foram isolados e identificados. Fosfolipase, hialuronidase, antígeno-5 e serinoprotease são proteínas antigênicas de elevada massa molecular que, quando injetadas durante o ato de ferroar, iniciam uma resposta imune peculiar, sensibilizando alguns indivíduos. Porém, poucos estudos têm sido realizados para a identificação e o mapeamento dos epítopos desses alérgenos. O conhecimento sobre a interação molecular dos principais alérgenos destes venenos certamente deverá contribuir para o aperfeiçoamento dos diagnósticos de alergia, bem como para o desenvolvimento de tratamentos mais seletivos de reações alérgicas mediadas por IgE. No presente estudo identificamos e mapeamos os epítopos lineares de células-B do antígeno-5 do veneno da vespa social Polybia paulista. O antígeno-5 é conhecido como um dos principais alérgenos do veneno de Hymenoptera com massa molecular em torno de 23 kDa e função biológica desconhecida, porém muitos estudos demonstram a sua alergenicidade. Tendo conhecimento da sequência primária do antígeno-5, a identificação e o mapeamento dos epítopos foram realizados através da síntese múltipla de peptídeos, utilizando as técnicas do SPOT-Synthesis, imunodetecção e método indireto do ELISA com soro de pacientes sensíveis... (resumo completo, clicar acesso eletrônico abaixo) / Abstract: The venom insects of Hymenoptera order contain a variety of allergenic proteins. The stings of these insects can induce allergic reactions and occasionally fatal anaphylaxis. There is a growing interest in the knowledge about the chemical components of the venom of these insects, especially in the field of allergy and clinical immunology. The main reactions of these venoms are inflammation and / or the induction of immune process in the victims; sometimes systemic effects also may be observed. Among the social Hymenoptera, the venoms of bees and wasps have been extensively studied and many of their molecular components have been isolated and identified. Phospholipase, hyaluronidase, antigen-5 and serine protease are antigenic proteins of high molecular weight, which may initiate a peculiar immune response to sensitize some individuals. However, few studies have been performed for the identification and mapping of the epitopes these allergens. The knowledge about the molecular interaction of the major allergens of these venoms with IgG and/or IgE will certainly contribute for improving the diagnosis of allergy, as well as to develop more selective treatments of reactions IgE-mediated allergy. In this study we identified and mapped the linear epitopes of B-cells of the antigen-5 from the venom of the social wasp Polybia paulista. The antigen-5 is known as one of the major allergens from Hymenoptera venoms with molecular weight around 23 kDa and unknown biological function, but many studies show its allergenicity. The aim of this study was to identify and to map the linear epitopes of B-cells of this allergen. Taking into account the knowledge the primary sequence of antigen-5, the identification and mapping of epitopes was performed by using multiple synthesis of peptides with the combination of different protocols: SPOT-Synthesis, immunoblotting and indirect method of ELISA with the sera... (Complete abstract click electronic access below) / Orientador: Mario Sergio Palma / Coorientador: Lucilene Delazari dos Santos / Banca: Salvatore Giovanni de Simone / Banca: Luisa Karla de Paula Arruda / Mestre

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