Thesis--Helsingfors.

Diss. / From the Amer. journal of psychology. v. 10, no. 1.

Diss. / From the Amer. journal of psychology. v. 10, no. 1.

Orientador: Andre Koch Torres de Assis / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica "Gleb Wataghin" / Made available in DSpace on 2018-07-27T10:18:38Z (GMT). No. of bitstreams: 1 Hernandes_JulioAkashi_M.pdf: 966851 bytes, checksum: 7b6753f4b60406c37c6d30d4d1ed715a (MD5) Previous issue date: 2001 / Resumo: Na primeira parte deste trabalho analisamos o campo elétrico fora de condutores resistivos estacionários conduzindo corrente constante. Exploramos aqui o ponto de vista das cargas superficiais. Apresentamos problemas resolvidos na literatura sobre este assunto, assim como resultados novos para condutores em forma de placas e também um anel filiforme (neste último caso calculamos numericamente o potencial), comparando os resultados teóricos com dados experimentais retirados da literatura. Na segunda parte, tratamos da propagação de sinais em condutores compridos. Seguimos a abordagem de Kirchho para o problema, utilizando a força de Weber como modelo de interação entre cargas. Conseguimos deriva a equação da telegrafia para diversos casos, e mostramos que a abordagem maxwelliana (campos) não é necessariamente a única que conduz à equação da telegrafia. O Apêndice A apresenta o cálculo das integrais envolvendo o potencial devido a uma placa retangular transportando uma corrente constante. O programa para calcular o potencial de um anel filiforme está listado no Apêndice B. No Apêndice C, consideramos o fenômeno da explosão de fios que acontece quando uma alta corrente elétrica flui em um condutor. Apresentamos o resultado da tensâo coulombiana, gerada pelo aparecimento de carga no interior do fio devido ao efeito Hall radial. Concluímos que esta tensão é várias ordens de grandeza inferior àquela necessária para romper um fio metálico, ver [AH99b] / Abstract: In the first part of this work we analyse the electric field created outside stationary resistive conductors, with a constant current. Here we explore the point of view of surface charges. We present solved problems in the literature, on this subject, and also new results for conductor plates and for a thin ring (in this last case we calculate the potential numerically), comparing our theoretical results with experimental data present in the literature. In the second part, we treat the propagation of signals in long conductors. We follow Kirchhoff's approach to the problem, utilizing Weber's force equation as a model for charge interaction. We derive the telegraphy equation for several cases, and show that the Maxwell's approach (based on fields) is not necessarily the only one that leads to the telegraphy equation. Appendix A presents the calculation of the integrals involved in the potential resolution for a rectangular plate transporting a constant current. The numerical program to calculate the potential of a thin ring is listed on Appendix B. On Appendix C we consider the phenomenon of wire explosions which happens when a high electric current ows in a conductor. We present the result of coulombian tension generated by the appearance of charges in the interior of the wire caused by the radial Hall effect. We conclude that this tension is several orders of magnitude smaller than the one necessary to break a metallic wire, see [AH99b] / Mestrado / Física / Mestre em Física

Orientador: Andre Koch Torres de Assis / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-18T13:27:01Z (GMT). No. of bitstreams: 1 Thober_DarioSassi_M.pdf: 1547657 bytes, checksum: 6f5e29476f2b2d25cd2d314616e636f6 (MD5) Previous issue date: 1993 / Resumo: O objetivo desta Tese é o estudo do fenômeno da indução de correntes entre circuitos pela eletrodinâmica de Weber. Mostramos que a lei de indução de Faraday é consequência da eletrodinâmica de Weber. Isto é mostrado de duas maneiras: (A) Calculando a força eletromotriz que vem da integração da força por unidade de carga ao longo de um circuito. (B) Calculando a força eletromotriz a partir da energia magnética dos circuitos. Outra questão analisada aqui se refere às induções de corrente quando não há variação aparente do fluxo de campo magnético no circuito induzido. Nessa classe de induções analisamos o caso das induções unipolares. Mostramos que a lei de Faraday da indução se aplica também nesses casos, como se verifica pela eletrodinâmica de Weber / Abstract: The goal of this work is the study of induced currents between circuits by Weber's electrodynamics. We show that Faraday's law of induction can be derived from Weber's electrodynamics. This is shown in two ways: (A) Calculating the electromotive force by the line integration of the force per unit charge along the circuit. (B) Calculating the electromotive force through the magnetic energy of the circuits. We also analyse the induction of currents when there is no apparent variation of the flux of the magnetic field. Unipolar induction is also analysed. We show that even in these cases Faraday's law of induction can be applied, as is verified by Weber's electrodynamics / Mestrado / Física / Mestre em Física

Cells process information from their environment, such as the stimuli to grow, divide, or die, via cell signaling. Deregulated processing of extracellular stimuli can lead to aberrant cell responses and cause cancer. Given that the in vivo cell environment constantly changes, it is important to understand how cells incorporate the context of their environment into their decision making processes. The idea of responding to relative, not absolute, changes in stimuli was first proposed in studies of human perception and became known as Weber's Law. Although, evidence of Weber's Law at the molecular level has been previously presented in studies of several organisms, to the best of our knowledge, it has never been explored in the case of relative sensing of extracellular stimuli in mammalian signaling cascades. The Mitogen-Activated Protein Kinase (MAPK) signaling pathway has been implicated in multiple human diseases, including cancers, and therefore cell signaling through this pathway is an important subject of research. Here we present a theoretical framework and an experimental validation of the mechanism of Weber's Law in the ability of cells to sense relative changes in the levels of extracellular stimuli in the MAPK signaling pathway. In particular, in this work we consider relative sensing in levels of Epidermal Growth Factor (EGF) in the MAPK pathway. We derive an analytical model of steady state behavior of the MAPK signaling pathway stimulated with constant doses of EGF. We demonstrate a mechanism that produces phosphorylation responses proportional to relative changes in ligand concentrations. The mechanism of Weber's Law presented here entails the retention of memory of the dose of the past chronic stimulation with EGF. The molecular mechanisms responsible for Weber's Law in MAPK signaling are likely to contribute to many other receptors signaling systems. Therefore, the mechanism of relative sensing of extracellular ligand concentrations derived here can be generalized beyond the EGF-activated MAPK signaling pathway to many other cell signaling systems. This thesis also presents a probabilistic framework to explore the parameter space of a detailed mechanistic ODE model of EGFR signaling cascades. The application of the model simulation allows us to generate probabilistic predictions of EGFR system behavior and to explore structure-to-function relationships between the model's parameter space and EGFR system responses. Overall, this work suggests an alternative view on the role of cellular endocytosis in the MAPK signaling in vivo. Specifically, traditionally viewed as a mechanism to downregulate and terminate cell signaling, endocytosis may enable cells to dynamically adjust their sensitivity to extracellular stimuli, and hence allow cells to integrate information about the past stimulations into the cell responses to the consequent stimulations and thus, cell fate decisions.

Submitted by VÍTOR FLÁVIO FURTADO DAMASCENO null (vitor_ffd@yahoo.com.br) on 2016-11-03T19:59:15Z No. of bitstreams: 1 Dissertação Definitiva com ficha e aprov.pdf: 1622796 bytes, checksum: 9b0b85e03f8767a6c8792fe9fc73caed (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-11-10T13:20:34Z (GMT) No. of bitstreams: 1 damasceno_vff_me_bot.pdf: 1622796 bytes, checksum: 9b0b85e03f8767a6c8792fe9fc73caed (MD5) / Made available in DSpace on 2016-11-10T13:20:34Z (GMT). No. of bitstreams: 1 damasceno_vff_me_bot.pdf: 1622796 bytes, checksum: 9b0b85e03f8767a6c8792fe9fc73caed (MD5) Previous issue date: 2016-09-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A avaliação da severidade - porcentagem da área lesionada em relação à área total - pode ser feita com auxílio de escalas diagramáticas, que são elaboradas com base na Lei WeberFechner e utilizam regressão linear simples em seu processo de validação, porém apresentam erros na metodologia estatística. O objetivo desta pesquisa foi propor um método de elaboração e validação de escalas de bacteriose em um híbrido Eucalyptus urophylla x Eucalyptus grandis, avaliar a da influência de concentrações de diferentes espécies de bactérias na validação de escalas, verificar a possibilidade de avaliações utilizando tons de cinza, e a influência da dispersão de lesões nas estimativas dos avaliadores no uso desta ferramenta. Foram conduzidos quatro experimentos com amostras das cidades de Bofete-SP e Botucatu-SP. No primeiro experimento, foram utilizadas 100 folhas de três clones (H13, I144 e AEC 1528) de Eucalyptus urophylla x Eucalyptus grandis infectadas naturalmente com bacteriose, que tiveram sua severidade medida para elaboração, por quartis e Weber-Fechner, e validação das seis escalas diagramáticas. No segundo, mudas de eucalipto com três concentrações diferentes (105, 107 e 109 indivíduos/mL) de inóculo de três bactérias (Pseudomonas sp., Xanthomonas sp. e mix) tiveram folhas coletadas para construção de três escalas diagramáticas. No terceiro, imagens digitais das amostras de folhas dos três clones de eucalipto infectados com bacteriose foram analisadas em tons de cinza. Houve estudo de correlação entre as variáveis considerando os três clones como um único grupo e separadamente. No quarto, a escala diagramática construída para o clone AEC 1528 foi repetida em diferentes níveis de dispersão, com a mesma severidade das folhas representativas dos níveis da escala, seguidas de avaliação. No primeiro experimento, o método de quartis apresentou melhoras nas leituras quando comparado ao método Weber-Fechner, houve diferença entre os clones segundo as avaliações e o uso de escalas foi favorável. No segundo, houve melhoras nas estimativas com o uso das escalas. No terceiro, os tons de cinza podem diferenciar a severidade dos clones como um único grupo e há separação de clones por severidade. No quarto, foi detectada influência direta da dispersão das lesões da doença nas estimativas dos avaliadores. Conclui-se que o método de quartis obteve melhores resultados que o método Weber-Fechner; escalas levando em consideração a concentração de inóculo podem resultar em diferenças nas avaliações; tons de cinza podem avaliar severidade e diferenciar clones; variações na dispersão de uma mesma severidade influenciam diretamente as estimativas de um avaliador. / The severity evaluation – percentage of the injured leaf area relative to its total – could be done with the assistance of diagrammatic scales, which are elaborated based on the WeberFechner law and uses simple linear regression for its validation process. However, errors can be found in statistical methodology. The objective of this research was to propose methods of elaboration and validation for diagrammatic scales of bacterial leaf blight on the hybrid Eucalyptus urophylla x Eucalyptus grandis, evaluate the influence of concentrations and different species of bacteria on scales validation, verify the possibilities of evaluations using gray scale, and the influence of leaf injuries dispersion on the estimates done by evaluators using this tool. Four experiments were conducted with samples from Bofete-SP and Botucatu-SP. In the first experiment, 100 leaves were used from three different clones (H13, I144 e AEC 1528) of Eucalyptus urophylla x Eucalyptus grandis naturally infected with bacterial leaf blight, which had the severity measured for the elaboration, by quartiles and Weber-Fechner law, and the validation of the six resultant diagrammatic scales. In the second one, eucalypt leaves with three different concentrations (105, 107 e 109 individuals/mL) of three bacterial inoculums (Pseudomonas sp., Xanthomonas sp. and mix), had their leaves collected for the construction of three diagrammatic scales. In the third, the digital images of the sampled leaves of the three eucalypt clones were analyzed using gray scale values. There was made a correlation among the variables considering the three clones as one single group and separately. In the fourth, the diagrammatic scale built for the clone AEC 1528 was replicated into different levels of dispersion with the same severity of the levels present in the scale, followed by evaluation. In the first experiment, the quartiles method presented reading improvements in comparison with the Weber-Fechner method. There was difference among the clones and the use of the scale was favorable. In the second, there were estimates improvements using the scales. In the third, the gray scale can detect the difference of severity of the clones as a single group and there is clone differentiation by severity. In the fourth, it was detected direct influence of the injuries dispersion in the evaluations. It concludes that the quartiles method had better results than the Weber-Fechner method; scales considering the concentration of the inoculum could result into evaluation differences; gray scale can be used for severity evaluation and clone differentiation; variations of the same dispersion of severity can influence directly the estimates of and evaluator.

In this thesis, we discuss three image processing topics: High Dynamic Range (HDR) image creation in scenes with motion, Tone Mapping (TM), and Demosaicking. The first part of this thesis focuses on the creation of HDR images using gradient fusion techniques, and proposes a method that deals with motion and avoids bleeding and ghost artifacts. In the second part, we tackle the TM problem, whose goal is to produce a low dynamic range picture from an HDR image that reproduces the sensation of an observer in the scene. We review the perceptual principles that we find important for TM purposes and present a new method that compares well to the state of the art. Finally, we propose a new method to reconstruct the three color channels of a picture taken with a Bayer filter. This problem is called Demosaicking and will be presented in the third part of this thesis. / En esta tesis tratamos tres temas de procesamiento de imagen: creación de imágenes de alto rango dinámico o HDR, Tone Mapping (TM) y Demosaicking. En la primera parte proponemos un método para la creación de imágenes HDR con movimiento que permite generar resultados sin artefactos de tipo bleeding y ghosting. En la segunda parte de la tesis tratamos el problema de TM cuyo objetivo es comprimir el rango dinámico de una imagen HDR para ser mostrada en una pantalla o impresa, simulando lo mejor posible la percepción de un sujeto en la escena. Presentaremos los principios sicofísicos que consideramos relevantes para TM y propondremos un método nuevo que mejora los resultados del estado del arte. Finalmente, en la tercera parte presentamos un método de Demosaicking o reconstrucción de los tres canales de color de una imagen tomada con un filtro de Bayer.