Multiple Sclerosis (MS) is a neurodegenerative autoimmune disease that affects millions of people worldwide. Although the exact cause of MS is unknown, it is clear that CD4+ T helper cells play a significant role, namely T helper 1 (Th1) and T helper 17 (Th17) cells. The Notch family of proteins plays a role in the development and differentiation of T helper cells. Previous data has shown that inhibition of Notch impairs the ability of T helper cell differentiation. Additionally specific inhibition of certain Notch members inhibits specific T helper cell differentiation, for example the inhibition of Notch 1 inhibits Th1 and iTreg polarization [Samon et al., 2008]. However, the effects of the other Notch family members on CD4+ T cells are not fully studied. We propose that Notch 3 plays an extensive role in the regulation of Th1, Th2, Th17, and iTreg polarizations. In addition, we propose that Notch 3 regulates function of T helper cell function in the mouse model of MS, experimental autoimmune encephalomyelitis (EAE). Data in this thesis show that Notch 3 plays a significant role in the polarization of Th1, Th17 and iTreg polarization [Karlsson et al., 2011]. We present evidence that the heterozygous and homozygous Notch 3 knockout exhibits a significant decrease in polarization toward Th1, Th17 and iTreg cell fates. Exopolysaccharide (EPS) is a compound that has been previously shown to play a protective role in other inflammatory diseases. EPS has been shown to produce anti-inflammatory macrophages. We propose that a similar anti-inflammatory effect might be possible in EAE. We found that EPS had a significant effect on EAE induction, decreasing the onset and peak disease score. EPS also reduced the concentration of IFN-γ, IL17A, and GM-CSF in the supernatants of the splenocytes after restimulation with MOG. Further experimental data is needed to prove the effects of EPS on EAE and the method by which EPS function. These data indicate that Notch 3 could be crucial in regards to EAE due to the effects on Th1 and Th17 which are instrumental in EAE induction [Raphael et al., 2015].

This thesis deals with the quality of service (QoS) mechanism in Evolved Packet System (EPS). The basic architecture and characteristics of the EPS are introduced. The concept of QoS is defined. Furthermore, QoS related entities, their functions and corresponding procedures are described. The methodology for measuring and evaluating of end-to-end QoS as seen from a user’s point of view is designed. This methodology is used to measure QoS of experimental cellular network at UTKO FEEC BUT. Finally, configuration change for optimizing the QoS support of experimental cellular network is designed.

The single bus voltage distributed architecture is the mainstay architecture for small satellite spacecraft. Even large satellites follow this architecture. While they may have more than one voltage that is distributed, such as a high voltage bus and a low voltage bus, within a subsystem, there is usually one bus voltage. Each subsystem component is responsible for further regulation or point-of-load regulation. The Nano-satellite class, and more particularly the cubesat, have broken away from this norm and overwhelmingly implement a centralized architecture. With the advances of small, highly efficient monolithic dc-dc converters, this thesis researches the possibilities of implementing the distributed architecture at the cubesat scale. The Goal is to create a very efficient electrical power system design that has a high degree of utility, allowing it to be used for multiple missions, without having to redesign the system every time.

No description available.

Myxococcus xanthus displays social (S) motility, a form of surface motility that is key to the multicellular behaviors of this organism. S motility requires two cellular structures: type IV pili (TFP) and exopolysaccharides (EPS). Previous studies have shown that M. xanthus does not use glucose or any other sugar as a primary carbon source. However, eight monosaccharides, namely glucose, mannose, arabinose, galactose, xylose, rhamnose, N-acetyl-glucosamine, and N-acetyl-mannosamine, are found in M. xanthus EPS. In this study, pathways that M. xanthus could use to produce the activated sugar monomers to form EPS are proposed based on genomic data. Of the eight sugars, pathways for seven were disrupted by mutation and their effects on the EPS-dependent behaviors were analyzed. The results indicate that disruption of the two pathways leading to the production of activated rhamnose (GDP- and TDP-rhamnose) affected fruiting body formation (GDP form only) and dye binding ability (both forms) but not S motility. Disruptions of the xylose, mannose, and glucose pathways caused M. xanthus to lose S motility, fruiting body formation, and dye binding abilities. An interruption in the pathway for galactose production created a mutant with properties similar to a lipopolysaccharide (LPS) deficient strain. This discovery led us to study the phenotypes of all mutant strains for LPS production. The results suggest that all mutants may synthesize defective LPS configurations. Disruption of the UDP-N-acetyl-mannosamine pathway resulted in a wild type phenotype. In addition, it was discovered that interruption of the pathway for N-acetyl-glucosamine production was possible only by supplementing this amino-sugar in the growth medium. In an attempt to determine if other mutants could be recovered by sugar supplementation, it was discovered that the Δpgi mutant can be rescued by glucose supplementation. The Dif chemotaxis-like pathway is known to regulate EPS production in M. xanthus. DifA is the upstream sensor of the pathway. Previous studies had created a NarX-DifA chimeric protein, NafA, that enables the activation of the Dif pathway by nitrate, the signal for NarX. In this study, we constructed a Δpgi difA double mutant containing NafA. This strain was then subjected to various incubations with glucose and/or nitrate to determine whether the point of EPS regulation by the Dif pathway is down- or up-stream of the step catalyzed by Pgi (phosphoglucose isomerase). Preliminary results from this study are inconclusive. / Master of Science

O poliestireno expandido (EPS), conhecido popularmente no Brasil como Isopor®, foi introduzido recentemente no país como material de baixa massa específica para construções de aterros, principalmente sobre solos moles, e encontro de pontes. Contudo, ainda não há experiência consolidada deste material em ensaios do ponto de vista da engenharia geotécnica entre nós. Este trabalho apresenta os resultados da primeira pesquisa com ensaios mecânicos e hidráulicos de laboratório específicos da caracterização do EPS para o uso geotécnico. Os ensaios mecânicos compreenderam compressão uniaxial simples e cíclica, compressão triaxial, cisalhamento direto e de interface (junta) e fluência em compressão. Os ensaios hidráulicos incluíram absorção de água por imersão e permeabilidade. Um ensaio de perda de massa por ataque de roedores foi realizado de forma simples, e ensaios químicos foram feitos para estudar o polímero. As amostras ensaiadas foram escolhidas de modo a se abranger ao máximo àquelas utilizadas em obras. Tentou-se, também, antecipar a utilização de amostras não convencionais, com massas específicas elevadas e de materiais reciclados. Os resultados mostram que o EPS possui uma grande resistência a solicitações de compressão simples, cíclica e triaxial, de cisalhamento, elevado valor de ângulo de atrito da junta e absorção de água, permeabilidade variável com a massa específica e baixo coeficiente de Poisson. Estas propriedades chave, aliado ao baixo peso específico oferecem a este material um grande potencial de aplicação como geossintético na engenharia geotécnica. / Expanded polystyrene (EPS), in Brazil, commonly know as Isopor®, has been recently introduced in this country as lightweight material for construction of embankments on soft soils, and bridge abutments. Despite this fact, there is no consolidated experience, in Brazil, in testing this product from a geotechnical point of view. This paper presents the first research data, obtained in Brazil, on mechanical and hydraulic laboratory tests, aiming the characterization of EPS samples specifically for geotechnical use. The mechanical tests comprised simple and cyclic unconfined compression, triaxial compression, joint and direct shear and creep in compression. The hydraulic tests included water absorption by immersion and water permeability. A simple loss weight test by mice attack was also conducted. And chemical tests were done to study the polymer. The results show that EPS has a great resistance to simple, cyclic and triaxial compression and joint shear solicitation, high friction angle and water absorption, varied permeability with the density and low Poisson coefficient. These key properties with its very low density give this material large potential application for geosynthetic use in geotechnical engineering.

A utilização de concreto leve decorre especialmente dos benefícios promovidos pela redução da massa específica do material, tais como menores esforços nas estruturas, economia com fôrmas e cimbramento, além de diminuição dos custos com transporte e montagem de construções pré-fabricadas. Atualmente, além das questões técnicas e econômicas, a escolha dos materiais de construção deve levar em conta os aspectos ambientais. Portanto, o uso de poliestireno expandido (EPS) na produção de concreto pode abrir portas para o emprego de resíduos de materiais dessa natureza, e ainda usufruir de sua baixa massa específica nas aplicações estruturais. Este trabalho teve como objetivo determinar as principais características do concreto leve com pérolas (esferas) de EPS, também conhecido como Concreto Ultraleve® ou Concreflex®, características essas necessárias para projetar elementos estruturais, e analisar o comportamento de lajes produzidas com esse novo material. Mais especificamente, foram determinadas características mecânicas, tais como: resistência à compressão, módulo de elasticidade e resistência à tração, na compressão diametral e na flexão, além de características de deformação de longo prazo, como retração e fluência. Também foi determinada a massa específica e avaliada sua relação com as características mecânicas, além dos ensaios de modelos de lajes unidirecionais produzidas com esse concreto. Para analisar a possibilidade de aplicação prática do concreto leve com EPS em lajes, foram elaboradas tabelas para pré-dimensionamento de lajes unidirecionais e bidirecionais com o novo material, nas quais essas lajes foram comparadas com as de concreto comum. Com base no procedimento experimental e nos resultados dos ensaios, o objetivo de determinar as características necessárias para projetar elementos estruturais de Concreto Leve com EPS foi alcançado. Pode-se ainda afirmar que o concreto estudado, com aproximadamente metade da massa específica dos concretos convencionais, apresenta características compatíveis com a produção e o uso comercial de lajes maciças, principalmente pré-moldadas, o que pode ser estendido a outros elementos que não necessitem de concretos com resistência muito alta. Também foi avaliado o comportamento de modelos de lajes de concreto leve com poliuretano (PU), de maneira semelhante ao estudo realizado com EPS, incluindo a caracterização do concreto de cada modelo. Para complementar a análise de desempenho do concreto leve com EPS, apresentou-se um estudo de carbonatação, que comprovou a excelente condição desse novo material com relação à durabilidade. / The use of lightweight concrete is mainly due to the benefits provided by reducing the density of the material such as smaller efforts on structures, economy of molds and scaffolding, as well as lower costs of transportation and erection of precast constructions. Currently, besides the technical and economic issues, the choice of building materials should take into account environmental aspects. Therefore, the use of expanded polystyrene (EPS) in the concrete production can open doors for the use of waste materials of this nature, and still to take advantage of its low density in structural applications. This study aimed to determine the main characteristics of the lightweight concrete with EPS beads (spheres), also named Ultra Lightweight Concrete, characteristics which are necessary to design structural members, and analyze the behavior of slabs produced with this new material. More specifically mechanical properties were determined, such as compressive strength, modulus of elasticity, and splitting and flexural tensile strength, as well as long term deformation properties such as shrinkage and creep. The density was also determined and evaluated its association with the mechanical characteristics, besides the tests of unidirectional slab models produced with this concrete. To analyze the possibility of use of the lightweight concrete with EPS in slabs, tables were compiled for pre-design of unidirectional and bidirectional slabs with this new material, in which these slabs were compared with those of common concrete. Based on the experimental procedure and results of tests, the aim of determine the characteristics necessary to design structural elements of lightweight concrete with EPS has been achieved. Can be also said that the studied concrete, with about half the density of conventional concrete, presents mechanical characteristics compatible with commercial production and use of slabs, mainly precast, conclusion which can be extended to other components that do not require concretes with very high strength. It was also assessed the behavior of slab models of lightweight concrete with polyurethane (PU) in a similar way to the study carried out with EPS, including the characterization of concrete for each model. To complement the performance analysis of the lightweight concrete with EPS a study of carbonation was presented, which proved the excellent condition of this new material with respect to durability.

O ferro é essencial para a sobrevivência das bactérias, estando envolvido em vários processos metabólicos. Apesar de sua baixa solubilidade, as bactérias dispõem de sistemas eficientes e específicos para captação, utilização e armazenamento desse metal, ao mesmo tempo controlando adequadamente a concentração de ferro livre no meio, para evitar seus potenciais efeitos tóxicos. Xylella fastidiosa é uma bactéria gram-negativa que coloniza o xilema de uma diversidade de plantas cultivadas e silvestres em várias partes do mundo, sendo o agente causador de uma série de doenças em plantas economicamente importantes como citros, videiras e café. Alguns mecanismos de virulência de X. fastidiosa já foram elencados, entre esses a formação de biofilme, que promoveria a oclusão do xilema e consequente estresse hídrico para a planta. Postula-se que a captação de ferro por X. fastidiosa, causando redução da concentração desse metal no xilema das plantas infectadas, seja uma das estratégias utilizadas pela bactéria em seu processo de infecção. Nosso objetivo neste trabalho foi de investigar o processo de captação de ferro por X. fastidiosa e avaliar em maior detalhe o efeito da concentração de ferro no crescimento e na expressão de fatores de virulência dessa bactéria, expandindo os estudos anteriormente realizados em nosso grupo. Para tal propusemos: (i) avaliar a capacidade de X. fastidiosa produzir sideróforos, pequenas moléculas quelantes de ferro; (ii) investigar, em condições de cultivo com diferentes concentrações de ferro, o perfil de expressão de alguns genes de X. fastidiosa que possam ser integrantes do stimulon do ferro; (iii) analisar o efeito da concentração de ferro no crescimento e formação de biofilme por X. fastidiosa. Observamos que X. fastidiosa parece produzir um composto quelante de ferro que pode ser um sideróforo e elencamos alguns genes que poderiam estar envolvidos na síntese desse composto. Confirmamos que ferro é necessário para o crescimento de X. fastidiosa, sendo que em alta concentração de ferro foi observada maior deposição de biofilme pela cultura bacteriana. Interessantemente também foi observado que as células crescidas em meio com pouco ferro secretaram mais exopolissacarídeos totais na fração do biofilme, o que estabelece uma relação entre as concentrações de ferro no meio com a expressão de um fator de virulência essencial para o desenvolvimento da infecção por X. fastidiosa. / Iron is an essential nutrient for bacteria, being involved in many metabolic processes. Despite its low solubility, bacteria present efficient and specific systems for uptake, utilization and storage of iron, meanwhile controlling metal concentration adequately to prevent potential toxic effects of free iron. Xylella fastidiosa is a Gram-negative bacterium which colonizes the xylem of a wide range of crops and wild species of plants worldwide. This bacterium is the agent of several diseases affecting economically important crops, such as citrus, grapevine and coffee. Among the proposed X. fastidiosa virulence mechanisms is the formation of biofilm which may occlude xylem vessels causing hydric stress. It is postulated that iron uptake might cause reduction of its concentration within the xylem of infected plants therefore constituting a virulence strategy during bacterial infection process. Our aims in this work were to investigate the process of iron uptake in X. fastidiosa and to evaluate the effect of iron concentration in the growth and morphology of this bacterium, expanding previous studies. For this we set to: (i) investigate the capacity of X. fastidiosa in producing siderophores, small biomolecules utilized for iron quelation; (ii) evaluate, under culture conditions at different iron concentrations, the expression profile of candidate genes that might be part of the iron stimulon; (iii) analyse the effect of iron concentration in growth and biofilm formation of X. fastidiosa. We observed that X. fastidiosa seems to produce a compound with iron quelating ability, such as a siderophore, and we point to a group of genes that might be involved in the synthesis of this compound. We confirmed that iron is necessary for growth of X. fastidiosa. At high concentrations of iron we observed higher biofilm production. Interestingly, we also observed that when grown in low iron concentration, X. fastidiosa secretes more exopolysaccharides (EPS) associated with the biofilm, suggesting a link between iron concentration and expression of an essential virulence factor to the infection process of X. fastidiosa.

Os sistemas construtivos vêm surgindo e evoluindo de acordo com a necessidade e a demanda de obras. Recentemente, a utilização de paredes portantes pré-moldadas vem sendo explorada como alternativa para construir edifícios com rapidez e eficácia. Outra tecnologia mais recente é o Concreto Ultraleve® Estrutural, ou concreto leve com EPS (CLE), em que o agregado graúdo e parte do miúdo são substituídos por pérolas de poliestireno expandido (EPS), contribuindo para reduzir o peso total do edifício, consequentemente diminuindo os esforços na estrutura e promovendo a redução nos custos com transporte e montagem dos elementos pré-moldados. Este trabalho apresenta como deve ser feito o dimensionamento de paredes portantes pré-moldadas, utilizando normas nacionais e internacionais. O principal objetivo do trabalho é apresentar um programa computacional desenvolvido para facilitar a análise e o dimensionamento de edifícios com paredes de concreto pré-moldado. Além disso, mostra-se o uso do programa para comparar o comportamento de edifício constituído por concreto com EPS e por concreto armado comum, e para avaliar a influência das juntas verticais na rigidez global. Portanto, além da importância acadêmica, este trabalho poderá ser de grande utilidade para o projeto de edifícios com paredes portantes pré-moldadas. / The construction systems have emerged and improved according to need and demand of works. Recently, the use of precast concrete walls has been explored as an alternative to construct buildings quickly and effectively. Another more recent technology is the lightweight concrete with polystyrene, wherein polystyrene beads replace the coarse aggregate and a part of the fine ones, contributing to reduce the weight of the building, thus decreasing the efforts in the structure and promoting a reduction in the cost of transport and erection of precast elements. This work shows how should be done the design of precast concrete walls using national and international standards. The main objective of the work is to present a computer program developed to facilitate the analysis and design of buildings with precast concrete walls. Moreover, the use of the program is shown to compare the behavior of building made with EPS concrete and ordinary concrete, and to evaluate the influence of vertical joints in the global stiffness. Therefore, besides the academic importance, this work can be useful for the design of buildings with precast loadbearing walls.

Made available in DSpace on 2015-03-26T13:27:59Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1030710 bytes, checksum: 9b0e0ff537803c01debc58646c785003 (MD5) Previous issue date: 2011-02-25 / The composition and adsorptive capacity of extracellular polymeric substances (EPS) in a eucalyptus bleached kraft pulp mill activated sludge plant were investigated. Samples of primary and secondary effluents and activated sludge were collected over five months. Effluents were characterized by quantifying dissolved organic carbon (DOC), chemical (COD) and biological (BOD) oxygen demands, adsorbable organic halogen (AOX), acid soluble lignin (ASL), and specific absorbance (SUVA254). EPS extracted from sludge were characterized in terms of protein, carbohydrates and DOC. The samples were analyzed by GC-MS to identify the main compounds present in effluents and in EPS extracts. In addition, a laboratory study was conducted to assess the relative importance of degradation and adsorption as removal mechanisms of organic matter in aerobic biological effluent treatment. The characterization results showed the profile of organic matter removal in the treatment system, with removal efficiencies of 85, 78 and 40% for BOD5, DOC and COD, respectively. High removal (40%) was also achieved for the compounds measured as AOX. The SUVA254 relationship increased slightly from 1.13 to 1.43 (L / mg.m). The characterization of EPS from the treatment plant sludge showed that proteins (19.9 mg / g VSS) represented 3.5 times more mass than carbohydrates (6.1 mg / g VSS), the DOC content was 6.0 mg / g VSS. Octadeca-9,12-dienoic and hexadecanoic acids were identified in EPS extracts, indicating the importance of participation of exopolymers in the adsorption of pollutants, since these lipophilic wood extractives were not degraded during the biological treatment and were identified with the same structures in the secondary effluent. In the organic matter adsorption study, the values of DOC, phenols and ASL were significantly lower after treatment with active biomass (AE) than after treatment with inactive biomass (IE) and without biomass (SE). COD and extractives showed no significant difference between AE, IE and SE treatments, although there was a tendency towards lower values of these parameters after AE treatment. EPS protein/carbohydrate ratios were 5.65, 6.95 and 6.05 for AE, IE and the control treatment, respectively. Average parameter values found in the laboratorystudy were higher than those found in the characterization of the EPS fromthe treatment plant sludge. The adsorptive capcity of EPS was verified from the results obtained in this study. / A composição e capacidade de adsorção das substâncias poliméricas extracelulares (EPS) do lodo ativado do sistema de lodos ativados de uma fábrica de polpa kraft branqueada de eucalipto foram investigadas. Amostras de efluente primário e secundário e do lodo biológico foram coletadas mensalmente ao longo de cinco meses. Os efluentes foram caracterizados quantos aos valores das demandas química (DQO) e bioquímica (DBO5) de oxigênio, carbono orgânico dissolvido (COD), halógenos orgânicos adsorvíveis (AOX), lignina solúvel em ácido (LSA), fenóis e absorbância ultravioleta específica (SUVA254). Extratos das EPS do lodo biológico foram preparados e caracterizados quanto aos teores de proteínas, carboidratos e COD. A identificação dos principais compostos presentes nos efluentes e nos extratos de EPS foi realizada por cromatografia gasosa- espectrometria de massa (CGEM). Um estudo laboratorial também foi realizado para avaliar a importânica relativa da degradação e adsorção para a remoção das diferentes classes de compostos orgânicos no tratamento biológico aeróbio. Os resultados da caracterização mostraram o perfil de remoção da matéria orgânica no sistema de tratamento. Houve remoção de 85, 78 e 40% para DBO5, DQOs e COD, respectivamente. Elevada remoção (40%) também foi conseguida para o AOX. A relação SUVA254 apresentou um ligeiro aumento de 1,13 para 1,43 (L/mg.m). A caracterização das EPS do lodo do sistema de tratamento da fábrica mostrou que as proteínas (19,9 mg/g SSV) representaram 3,5 vezes mais massa das EPS do que os carboidratos (6,1 mg/g SSV), o contéudo de COD total foi 6,0 mg/g SSV. Os ácidos octadeca-9,12-dienóico e hexadecanóico foram identificados em extratos de EPS, evidenciando importância da participação dos exopolímeros na adsorção dos poluentes, já que estes extrativos lipofílicos da madeira não foram degradados durante o tratamento biológico, pois puderam ser identificados com as mesmas estruturas no efluente secundário. vii Nos estudos de adsorção da matéria orgânica, os valores de COD, LSA e fenóis totais foram significativamente menores após o tratamento com biomassa ativa (AE) do que após os tratamentos com biomassa inativa (IE) e sem biomassa (SE). Para a DQO e os extrativos, não foi observada diferença significativa entre os tratamentos AE, IE e SE, embora houvesse uma tendência de menores valores desses parâmetros após o tratamento AE. A relação proteína/carboidratos foi de 5,65, 6,95 e 6,05, para AE, IE e o controle, respectivamente. Os valores médios dos parâmetros encontrados no estudo laboratorial foram superiores aos resultados obtidos na caracterização das EPS do lodo sistema de tratamento da fábrica. Através dos experimentos foi possivel verificar a propriedade adsortiva das EPS.