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Estudo da variabilidade genética e dos fatores de virulência de isolados de Ureaplasma diversum. / Study of genetic variability and virulence factors of Ureaplasma diversum isolates.Marques, Lucas Miranda 23 June 2009 (has links)
O presente trabalho teve como objetivo o estudo da variabilidade genética e dos fatores de virulência de isolados de U. diversum. As cepas foram submetidas a sequenciamento dos genes da urease e 16S rRNA e a testes para verificar os fatores de virulência: cápsula, fosfolipase C, IgAse e adesão e invasão. A análise do sequênciamento parcial do gene 16S rRNA resultou na presença de polimorfismos em 44 posições da seqüência, que diferenciou as amostras em sete grupos. Em relação aos fatores de virulência, os dados mostraram que as cepas estudadas apresentaram uma camada densa ao redor da membrana celular dos microrganismos e atividade de fosfolipase C. No entanto, não foi observado a atividade de IgAse nas cepas. Em relação a atividade de invasão, observou-se que os ureaplasma estudados puderam ser visualizados no interior de células Hep-2 com apenas um minutos de infecção, sendo observados em uma região perinuclear, mas não no interior do núcleo. Além disto, pode verificar que entre 1% a 10% dos ureaplasmas estudos penetraram na célula pelo teste da gentamicina. / The aim of the present study was the study of genetic variability and virulence factors of U. diversum clinical isolates. The strains were submitted to sequencing for 16S rRNA and urease genes. Moreover, the strains were analyzed to the virulence factors: capsule, phospholipase C, IgA protease and adhesion and invasion into Hep-2 cells. The sequencing of parcial 16S rRNA gene showed polymorphic patterns into 44 positions. These polymorphisms clustered the strains in seven groups. For the virulence factors, ureaplasma cells showed a dense-stained external capsule-like structure surrounding the cell membrane. A high level of phospholipase C activity was also detected in 31 studied ureaplasma. However, no strains showed IgA protease activity. For the invasion assay, the isolates and strains used were detected inside the cells after infection of one minute. The invasions of the ureaplasmas surrounded the nuclear region but were not observed inside the nuclei. The gentamicin invasion assay detected that 1% to 10% of studied ureaplasmas were inside the infected cells.
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Estudo da variabilidade genética e dos fatores de virulência de isolados de Ureaplasma diversum. / Study of genetic variability and virulence factors of Ureaplasma diversum isolates.Lucas Miranda Marques 23 June 2009 (has links)
O presente trabalho teve como objetivo o estudo da variabilidade genética e dos fatores de virulência de isolados de U. diversum. As cepas foram submetidas a sequenciamento dos genes da urease e 16S rRNA e a testes para verificar os fatores de virulência: cápsula, fosfolipase C, IgAse e adesão e invasão. A análise do sequênciamento parcial do gene 16S rRNA resultou na presença de polimorfismos em 44 posições da seqüência, que diferenciou as amostras em sete grupos. Em relação aos fatores de virulência, os dados mostraram que as cepas estudadas apresentaram uma camada densa ao redor da membrana celular dos microrganismos e atividade de fosfolipase C. No entanto, não foi observado a atividade de IgAse nas cepas. Em relação a atividade de invasão, observou-se que os ureaplasma estudados puderam ser visualizados no interior de células Hep-2 com apenas um minutos de infecção, sendo observados em uma região perinuclear, mas não no interior do núcleo. Além disto, pode verificar que entre 1% a 10% dos ureaplasmas estudos penetraram na célula pelo teste da gentamicina. / The aim of the present study was the study of genetic variability and virulence factors of U. diversum clinical isolates. The strains were submitted to sequencing for 16S rRNA and urease genes. Moreover, the strains were analyzed to the virulence factors: capsule, phospholipase C, IgA protease and adhesion and invasion into Hep-2 cells. The sequencing of parcial 16S rRNA gene showed polymorphic patterns into 44 positions. These polymorphisms clustered the strains in seven groups. For the virulence factors, ureaplasma cells showed a dense-stained external capsule-like structure surrounding the cell membrane. A high level of phospholipase C activity was also detected in 31 studied ureaplasma. However, no strains showed IgA protease activity. For the invasion assay, the isolates and strains used were detected inside the cells after infection of one minute. The invasions of the ureaplasmas surrounded the nuclear region but were not observed inside the nuclei. The gentamicin invasion assay detected that 1% to 10% of studied ureaplasmas were inside the infected cells.
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Las Indicaciones Geográficas en Chile: El Caso del Limón de PicaCáceres Bustamante, Javiera 12 October 2017 (has links)
Estudio de caso para optar al grado de magíster en Estrategia Internacional y Política Comercial. / Las Indicaciones Geográficas son activos intangibles que otorgan valor a un producto con características únicas derivadas de su lugar de origen. Estos productos son altamente cotizados en mercados internacionales, ya que actualmente, consumidores adquieren productos que certifiquen su calidad, reputación y origen. En el caso de Chile, no existe una sensibilización acerca de la importancia de estos Derechos de Propiedad Intelectual, sólo existen 12 productos registrados. El Limón de Pica fue el primer producto en obtener esta certificación en el año 2010.
Este estudio da a conocer los principales motivos de un grupo de productores para obtener la Indicación Geográfica del Limón de Pica, y determinar los efectos que esta obtención trajo al desarrollo de la localidad de Pica. Se entrega información acerca del trabajo que realizaron productores, el sector público y privado para obtener el registro y, posteriormente, para posicionar al Limón de Pica en el mercado nacional e internacional.
Siete años después de obtener el registro, factores cómo el desconocimiento acerca del tema, la falta de asociatividad entre productores y los proyectos a corto plazo, han impedido su utilización. El sector público les ha dado un gran apoyo para sacar adelante su Indicación Geográfica, pero parecen no responder a las verdaderas necesidades de los actores. / Geographical Indications are intangible assets that add value to a product with unique characteristics deriving from their geographical origin. These products are highly valued in international markets and, nowadays, consumers mainly acquire certified products that protect their quality, reputation and origin. In the Chilean case, there is a need to increase awareness about the importance of Intellectual Property Rights, specially about Geographical Indications. There are only 12 products registered in Chile and Limón de Pica was the first product that obtained this certification in 2010.
This investigation shows the main reasons why a group of people obtained Limón de Pica Geographical Indication, and it determines its effects on the local development of Pica. This investigation also gives information regarding how farmers, and the public and private sector worked to obtain this certification and to promote Limón de Pica in both national and international markets.
Seven years have passed since they received the certification, but elements such as lack of knowledge, lack of cooperative work and short-time projects, have hindered its use. The public sector has provided them with a great support to develop their Geographical Indication, but it seems that they have not been able to fulfill farmers’ true needs.
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Development of Efficient Computational Methods for Better Estimation of Optical Properties in Diffuse Optical TomographyRavi Prasad, K J January 2013 (has links) (PDF)
Diffuse optical tomography (DOT) is one of the promising imaging modalities that pro-
vides functional information of the soft biological tissues in-vivo, such as breast and brain tissues. The near infrared (NIR) light (600-1000 nm) is the interrogating radiation, which is typically delivered and collected using fiber bundles placed on the boundary of the tissue. The internal optical property distribution is estimated via model-based image reconstruction algorithm using these limited boundary measurements.
Image reconstruction problem in DOT is known to be non-linear, ill-posed, and some times under-determined due to the multiple scattering of NIR light in the tissue. Solving this inverse problem requires regularization to obtain meaningful results, with Tikhonov-type regularization being the most popular one. The choice of the regularization parameter dictates the reconstructed optical image quality and is typically chosen empirically or based on prior experience. An automated method for optimal selection of regularization parameter that is based on regularized minimal residual method (MRM) is proposed and is compared with the traditional generalized cross-validation method. The results obtained using numerical and gelatin phantom data indicate that the MRM-based method is capable of providing the optimal regularization parameter.
A new approach that can easily incorporate any generic penalty function into the
diffuse optical tomographic image reconstruction is introduced to show the utility of non-quadratic penalty functions. The penalty functions that were used include, quadratic (`2), absolute (`1), Cauchy, and Geman-McClure. The regularization parameter in each of these cases were obtained automatically using the generalized cross-validation (GCV) method. The reconstruction results were systematically compared with each other via utilization of quantitative metrics, such as relative error and Pearson correlation. The reconstruction results indicate that while quadratic penalty may be able to provide better separation between two closely spaced targets, it's contrast recovery capability is limited and the sparseness promoting penalties, such as `1, Cauchy, Geman-McClure have better utility in reconstructing high-contrast and complex-shaped targets with Geman-McClure penalty being the most optimal one.
Effective usage of image guidance by incorporating the refractive index (RI) variation in computational modeling of light propagation in tissue is investigated to assess its impact on optical-property estimation. With the aid of realistic patient breast three-dimensional models, the variation in RI for different regions of tissue under investigation is shown to influence the estimation of optical properties in image-guided diffuse optical tomography (IG-DOT) using numerical simulations. It is also shown that by assuming identical RI for all regions of tissue would lead to erroneous estimation of optical properties. The a priori knowledge of the RI for the segmented regions of tissue in IG-DOT, which is difficult to obtain for the in vivo cases, leads to more accurate estimates of optical properties. Even inclusion of approximated RI values, obtained from the literature, for the regions of tissue resulted in better estimates of optical properties, with values comparable to that of having the correct knowledge of RI for different regions of tissue.
Image reconstruction in IG-DOT procedure involves reduction of the number of optical parameters to be reconstructed equal to the number of distinct regions identified
in the structural information provided by the traditional imaging modality. This makes
the image reconstruction problem to be well-determined compared to traditional under-
determined case. Still, the methods that are deployed in this case are same as the one
used for traditional diffuse optical image reconstruction, which involves regularization
term as well as computation of the Jacobian. A gradient-free Nelder-Mead simplex
method was proposed here to perform the image reconstruction procedure and shown
to be providing solutions that are closely matching with ones obtained using established
methods. The proposed method also has the distinctive advantage of being more efficient due to being regularization free, involving only repeated forward calculations.
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Electromechanics of an Ocean Current TurbineTzelepis, Vasileios 18 December 2015 (has links)
The development of a numeric simulation for predicting the performance of an Ocean Current Energy Conversion System is presented in this thesis along with a control system development using a PID controller for the achievement of specified rotational velocity set-points. In the beginning, this numeric model is implemented in MATLAB/Simulink® and it is used to predict the performance of a three phase squirrel single-cage type induction motor/generator in two different cases. The first case is a small 3 meter rotor diameter, 20 kW ocean current turbine with fixed pitch blades, and the second case a 20 meter, 720 kW ocean current turbine with variable pitch blades. Furthermore, the second case is also used for the development of a Voltage Source Variable Frequency Drive for the induction motor/generator. Comparison among the Variable Frequency Drive and a simplified model is applied. Finally, the simulation is also used to estimate the average electric power generation from the 720 kW Ocean Current Energy Conversion System which consists of an induction generator and an ocean current turbine connected with a shaft which modeled as a mechanical vibration system.
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Etude de la dynamique des adhésions neuronales N-cadhérine et L1 dans la croissance axonale et la synaptogenèsePruvost Née Dequidt, Caroline 16 May 2007 (has links) (PDF)
Lors des processus développementaux d'élongation axonale et de synaptogenèse, les protéines d'adhésion telles les cadhérines ou les Ig-CAM jouent des rôles fondamentaux en permettant la formation de contacts entre neurones. Pour étudier la dynamique de ces contacts et leurs rôles dans ces processus, nous avons mis en œuvre des techniques d'imagerie sur des neurones primaires d'hippocampe (clivage thrombine, FRAP, pinces optiques, quantum-dots), ceux-ci étant associés à un système semi-artificiel de microsphères recouvertes de protéines d'adhésion purifiées (N-cadhérine et L1). En utilisant une construction L1 portant une étiquette GFP extracellulaire clivable à la thrombine, j'ai pu précisé l'implication des processus de diffusion membranaire et d'exo- endocytose dans la dynamique des contacts L1-dépendants et obtenir des données quantitatives relatives à l'interaction homophile L1. J'ai également contribué à caractériser la liaison extracellulaire entre N-cadhérine et GluR2, sous-unité des récepteurs AMPA, et l'influence de l'expression de la N-cadhérine sur la mobilité de GluR2. L'interaction entre ces deux protéines pourrait être impliquée dans la formation et/ou la maturation des synapses.
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