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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.
51

Posouzení vlivu dělícího poměru na pasivní optickou síť / Impact assessment of split ratios on passive optical network

Gallo, Martin January 2016 (has links)
This thesis deals with the most recent passive optical network standard NG-PON2, describes the sublayer model which includes error correction coding during propagation in optical fibres. Assesses the impact of split ratios using the simulation environment created from defined model and compares various scenarios. Discusses possible sources of errors of simulation model in compare to real deployment.
52

Scalability of Kubernetes Running Over AWS - A Performance Study while deploying CPU intensive application containers

MOGALLAPU, RAJA January 2019 (has links)
Background: Nowadays lot of companies are enjoying the benefits of kubernetes by maintaining their containerized applications over it. AWS is one of the leading cloud computing service providers and many well-known companies are their clients. Many researches have been conducted on kubernetes, docker containers, cloud computing platforms but a confusion exists on how to deploy the applications in Kubernetes. A research gap about the impact created by CPU limits and requests while deploying the Kubernetes application can be found. So, through this thesis I want to analyze the performance of the CPU intensive containerized application. It will help many companies avoid the confusion while deploying their applications over kubernetes. Objectives: We measure the scalability of kubernetes under CPU intensive containerized application running over AWS and we can study the impact created by changing CPU limits and requests while deploying the application in Kubernetes. Methods: we choose a blend of literature study and experimentation as methods to conduct the research. Results and Conclusion: From the experiments it is evident that the application performs better when we allocate more CPU limits and less CPU requests when compared to equal CPU requests and CPU limits in the deployment file. CPU metrics collected from SAR and Kubernetes metrics server are similar. It is better to allocate pods with more CPU limits and CPU requests than with equal CPU requests and CPU limits for better performance. Keywords: Kubernetes, CPU intensive containerized application, AWS, Stress-ng.
53

Samspel i matematikundervisningen : Ett lärarperspektiv på elevers samspel för lärande i matematik / Interaction in mathematics teaching : A teacher perspective on students´interaction for learning in mathematics

Nilsson, Cecilia, Lexander, Louise January 2021 (has links)
Studiens syfte var att utforska elevers möjlighet till samspel i matematikundervisningen, ur ett lärarperspektiv. Tidigare forskning i studien visar att samspel är bra för elevers studieresultat inom matematik,samt vilka kritiska faktorer som kan uppstå vid arbete i par och grupp.Studien utgår från den sociokulturella teorin, som menar att lärande sker i sociala sammanhang.Utifrån studiens syfte formulerades följande frågeställningar:- Vilken betydelse anser lärare, som undervisar i de yngre åldrarna, att arbete i par eller i mindre grupper har för lärandet i matematik? - Vad i undervisningen i form av aktiviteter och uppgifter ger elever möjlighet att samspela i lärandet i matematik, enligt lärarna? - Vilka kritiska faktorer ser lärare gällande samspel som undervisningsmetod i matematik? För att besvara frågeställningarna genomfördes en kvantitativ studie med kvalitativa inslag, endigital enkätundersökning där 85 undervisande, behöriga lärare i årskurs 1-3 deltog. Studiens analys utgick från Engeströms modell av aktivitetsteorin som grundar sig i det sociokulturella perspektivet och bygger på att det finns ett samspel mellan människa, miljö och den aktivitet som människan deltar i.Resultatet visade att lärare för de yngre åldrarna anser att samspel har betydelse för elevers lärande i matematik och eleverna får enligt lärarna samspela vid främst laborativa och muntliga uppgifter.
54

Efeitos da inibição crônica das óxido nítrico sintases na mecânica de tecido periférico, no recrutamento eosinofílico e no remodelamento da matriz extracelular induzida por inflamação crônica pulmonar / Effects of chronic nitric oxide inhibition on lung tissue mechanics, eosinophilic and extracellular matrix responses induced by chronic pulmonary inflammation

Silva, Patricia Angeli da 25 September 2008 (has links)
INTRODUÇÃO: A importância da resposta mecânica do parênquima pulmonar na fisiopatologia da asma tem sido recentemente reconhecida. O óxido nítrico é um mediador que controla o tônus muscular liso das vias aéreas, porém este efeito no parênquima pulmonar periférico ainda não foi previamente investigado. Nossa hipótese é que a inibição crônica das óxido nítrico sintases por meio do tratamento com L-NAME (falso substrato para todas as óxido nítrico sintases) pode modular a mecânica do parênquima pulmonar, o recrutamento eosinofílico e o remodelamento da matriz extracelular em modelo de inflamação alérgica crônica pulmonar em cobaias. MÉTODOS: Os animais foram expostos a sete inalações com soro fisiológico ou com ovoalbumina em doses crescentes (1~5mg/ml - 4 semanas) e tratadas ou não com L-NAME (60 mg/kg/ por dia /por animal) na água de beber. Setenta e duas horas após a sétima inalação os animais foram anestesiados, exsanguinados e a mecânica oscilatória do parênquima pulmonar foi medida na condição pré e após desafio (0.1%). Utilizando a técnica de morfometria foram avaliadas a densidade de eosinófilos, o número de células nNOS e iNOS positivas, a densidade de actina, das fibras colágenas e das fibras elásticas bem como a proporção de volume de 8-iso-PGF2 no septo alveolar. RESULTADOS: Os animais que foram expostos à ovoalbumina apresentaram um aumento da resistência e da elastância tecidual (resposta basal e após desafio antigênico), na densidade de eosinófilos, no número de células nNOS e iNOS positivas, na densidade de fibras colágenas e de fibras elásticas bem como na expressão de 8-isoPGF2 no septo alveolar comparativamente aos grupos controles (p<0,05). O tratamento com L-NAME em animais expostos à ovoalbumina atenuou todas as respostas de mecânica do tecido pulmonar periférico (p<0, 01), reduziu o número de células nNOS e iNOS positivas (p<0.01), o conteúdo de fibras elásticas (p<0,001) e de 8-iso-PGF2 no septo alveolar (p<0,001). No entanto, este tratamento não afetou o número total de eosinófilos e o conteúdo de fibras colágenas. Este trabalho sugere que o óxido nítrico contribui para a constrição do parênquima pulmonar e para a deposição de fibras elásticas neste modelo. Estes efeitos foram associados à ativação de iNOS e nNOS em células do parênquima distal e aumento na via do estresse oxidativo / The importance of lung tissue mechanical responses in asthma pathophysiology has been recently recognized. Although nitric oxide (NO) is a mediator that controls smooth muscle tonus control in the airways, its effects on lung tissue responsiveness has not been previously investigated. We hypothesized that chronic nitric oxide synthase inhibition by L-NAME (false substrate for all nitric oxide synthases) treatment may modulate lung tissue mechanics, eosinophilic recruitment and extracellular matrix remodeling in a model of chronic pulmonary allergic inflammation. Guinea pigs were submitted to seven normal saline or ovalbumin exposures with increasing doses (1~5mg/mL-4weeks) and treated or not with L-NAME in drinking water. Seventy-two hours after the seventh inhalation the animals were anesthetized, exsanguinated, and oscillatory mechanics of lung tissue strips was performed in baseline condition and after ovalbumin challenge (0.1%). Using morphometry, we assessed the density of eosinophils, the number of iNOS and nNOS-positive cells, the density of actin, the collagen and elastic fibers content and the volume proportion of 8-iso-PGF2 in the alveolar septa. Ovalbumin-exposed animals presented an increase in baseline and maximal tissue resistance and elastance responses, eosinophil density, in the number of iNOS and nNOS positive cells, in the amount of collagen and elastic fibers and in the volume proportion of 8-iso-PGF2 in the alveolar septa compared to controls (p<0.05). L-NAME treatment in ovalbumin-exposed animals attenuated all lung tissue mechanical responses (p<0.01), reduced the number of iNOS and nNOS positive cells (p<0.01), elastic fiber content (p<0.001) and 8-isoPGF2 in the alveolar septa (p<0.001). However, this treatment did not affect the total number of eosinophils and collagen deposition. These data suggest that NO contributes to distal lung parenchyma constriction and to elastic fibers deposition in this model. These effects were associated to iNOS and nNOS activation in pulmonary parenchyma and with an increase in oxidative stress pathway activation
55

Efeitos da inibição crônica das óxido nítrico sintases na mecânica de tecido periférico, no recrutamento eosinofílico e no remodelamento da matriz extracelular induzida por inflamação crônica pulmonar / Effects of chronic nitric oxide inhibition on lung tissue mechanics, eosinophilic and extracellular matrix responses induced by chronic pulmonary inflammation

Patricia Angeli da Silva 25 September 2008 (has links)
INTRODUÇÃO: A importância da resposta mecânica do parênquima pulmonar na fisiopatologia da asma tem sido recentemente reconhecida. O óxido nítrico é um mediador que controla o tônus muscular liso das vias aéreas, porém este efeito no parênquima pulmonar periférico ainda não foi previamente investigado. Nossa hipótese é que a inibição crônica das óxido nítrico sintases por meio do tratamento com L-NAME (falso substrato para todas as óxido nítrico sintases) pode modular a mecânica do parênquima pulmonar, o recrutamento eosinofílico e o remodelamento da matriz extracelular em modelo de inflamação alérgica crônica pulmonar em cobaias. MÉTODOS: Os animais foram expostos a sete inalações com soro fisiológico ou com ovoalbumina em doses crescentes (1~5mg/ml - 4 semanas) e tratadas ou não com L-NAME (60 mg/kg/ por dia /por animal) na água de beber. Setenta e duas horas após a sétima inalação os animais foram anestesiados, exsanguinados e a mecânica oscilatória do parênquima pulmonar foi medida na condição pré e após desafio (0.1%). Utilizando a técnica de morfometria foram avaliadas a densidade de eosinófilos, o número de células nNOS e iNOS positivas, a densidade de actina, das fibras colágenas e das fibras elásticas bem como a proporção de volume de 8-iso-PGF2 no septo alveolar. RESULTADOS: Os animais que foram expostos à ovoalbumina apresentaram um aumento da resistência e da elastância tecidual (resposta basal e após desafio antigênico), na densidade de eosinófilos, no número de células nNOS e iNOS positivas, na densidade de fibras colágenas e de fibras elásticas bem como na expressão de 8-isoPGF2 no septo alveolar comparativamente aos grupos controles (p<0,05). O tratamento com L-NAME em animais expostos à ovoalbumina atenuou todas as respostas de mecânica do tecido pulmonar periférico (p<0, 01), reduziu o número de células nNOS e iNOS positivas (p<0.01), o conteúdo de fibras elásticas (p<0,001) e de 8-iso-PGF2 no septo alveolar (p<0,001). No entanto, este tratamento não afetou o número total de eosinófilos e o conteúdo de fibras colágenas. Este trabalho sugere que o óxido nítrico contribui para a constrição do parênquima pulmonar e para a deposição de fibras elásticas neste modelo. Estes efeitos foram associados à ativação de iNOS e nNOS em células do parênquima distal e aumento na via do estresse oxidativo / The importance of lung tissue mechanical responses in asthma pathophysiology has been recently recognized. Although nitric oxide (NO) is a mediator that controls smooth muscle tonus control in the airways, its effects on lung tissue responsiveness has not been previously investigated. We hypothesized that chronic nitric oxide synthase inhibition by L-NAME (false substrate for all nitric oxide synthases) treatment may modulate lung tissue mechanics, eosinophilic recruitment and extracellular matrix remodeling in a model of chronic pulmonary allergic inflammation. Guinea pigs were submitted to seven normal saline or ovalbumin exposures with increasing doses (1~5mg/mL-4weeks) and treated or not with L-NAME in drinking water. Seventy-two hours after the seventh inhalation the animals were anesthetized, exsanguinated, and oscillatory mechanics of lung tissue strips was performed in baseline condition and after ovalbumin challenge (0.1%). Using morphometry, we assessed the density of eosinophils, the number of iNOS and nNOS-positive cells, the density of actin, the collagen and elastic fibers content and the volume proportion of 8-iso-PGF2 in the alveolar septa. Ovalbumin-exposed animals presented an increase in baseline and maximal tissue resistance and elastance responses, eosinophil density, in the number of iNOS and nNOS positive cells, in the amount of collagen and elastic fibers and in the volume proportion of 8-iso-PGF2 in the alveolar septa compared to controls (p<0.05). L-NAME treatment in ovalbumin-exposed animals attenuated all lung tissue mechanical responses (p<0.01), reduced the number of iNOS and nNOS positive cells (p<0.01), elastic fiber content (p<0.001) and 8-isoPGF2 in the alveolar septa (p<0.001). However, this treatment did not affect the total number of eosinophils and collagen deposition. These data suggest that NO contributes to distal lung parenchyma constriction and to elastic fibers deposition in this model. These effects were associated to iNOS and nNOS activation in pulmonary parenchyma and with an increase in oxidative stress pathway activation
56

Pevnostní návrh ostruhy letadla / Strength design of the aircraft spur

Profota, Martin January 2017 (has links)
This master thesis deals with computational stress-strain analysis of the tailskid of airplane L410 NG with main focus firstly the check current design of the tailskid and then the design another design solution with the able to absorb as much as possible the deformation energy. Solution of this problem is performed using computational modeling utilizing numerical simulation of quasi-static and crash deformation load of the tailskid with using explicit Finite Element Method (FEM) in program ABAQUS v6.14. After the introduction with problem situation and tailskid assembly introductory part is devoted to the research study of various designs of the tailskid for different types of airplanes. There follows these theoretical general principles of thin-walled structures and buckling of them. Before the creating of the computational model itself, the explicit form of the Finite Element Method is better described. The conclusion of this thesis deals with the mutual comparison of the most advantageous design variants of the tailskid and the selection of the most suitable one of them for the airplane L410 NG.
57

Technologie NG - PON / NG - PON technologies

Balon, Radek January 2013 (has links)
The main object of the master thesis was to familiarize with optical networks, describe the latest current technology of passive optical networks and create a simple simulation of our chosen technology. This thesis was divided into several parts. The first part deals with passive network architecture. I illustrated the basic functional elements which are present in optical networks. I described the active elements and principles of data transmission in the distribution network. To conclude this chapter I described the different standards that are defined for the passive network. In second part I familiarized myself with key parameters and their adverse effect on the transmitted signal. Another part deals with the new technologies that are defined for the next generation of passive network NG-PON. I described the principles of data transmission in these networks and their advantages and disadvantages. The last part deals with creating custom simulations of technology defined by standard NG-PON using OptSim 05.02 Subsequently I have collated all the results of the various technologies and show the advantages and disadvantages of each.
58

O bilinguismo como elemento de reafirma??o da etnocultura na educa??o escolar da aldeia ind?gena Tekrejar?tire / Bilingualism as an element of reaffirmation of ethnoculture in the school education of the Tekrejar?tire indigenous village

MUNDOCO, Rosil?ia de Oliveira 12 June 2017 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-08-28T20:01:56Z No. of bitstreams: 1 2017 - Rosil?ia de Oliveira Mundoco.pdf: 1053062 bytes, checksum: 681b2c733eab650b506546a36985265e (MD5) / Made available in DSpace on 2018-08-28T20:01:56Z (GMT). No. of bitstreams: 1 2017 - Rosil?ia de Oliveira Mundoco.pdf: 1053062 bytes, checksum: 681b2c733eab650b506546a36985265e (MD5) Previous issue date: 2017-06-12 / The present study had as its object the study of bilingualism and its contribution to the reaffirmation of ethnoculture in the school education of the indigenous village Tekrejar?tire. The village is located in the indigenous territory of Las Casas, in the southeastern region of the state of Par?. It is made up of indigenous people known as the Kaiap? exoneration, but they call themselves the Meb?ng?kre, meaning "the men of the place among the waters." In the village is situated the EMEF (Municipal School of Indigenous Education of Fundamental Education) Kaiap?, being this the locus of this research. Considering the peculiarities and necessities that urge when addressing the subject of indigenous school education, the present research gathered data about the presence of the Meb?ng?kre culture in indigenous school education, having as a reaffirmation element bilingualism, including the right to preserve ethnoculture and Education. At the outset, the context of the survey is presented describing the Meb?ng?kre people, Tekrejar?tire village and EMEF Kaiap?. In this sense, he broadly outlined important concepts for the development of research, including the theoretical basis of subjects such as Indigenous School Education in Brazil, Indigenous School Education in Par?, Ethnocultural concept, Meb?ng?kre Culture including his native language, Diglossia, diverse Conceptions about bilingualism, and also brought a chronological presentation of bilingualism in indigenous school education throughout our history, from Brazil empire reaching current policies, such as Law 11.645/2008, which makes it mandatory to teach Afro-Indian history , And the policy of quotas for the entry of indigenous people into universities. The methodological paths followed for this qualitative descriptive-exploratory research were based on documentary analysis, questionnaires, interviews, conversations and observation, through which it was possible to verify how this content has been approached in the teaching praxis, as well as how bilingualism reveals itself In the school environment through the actors involved in the educational process of the school and also, as bilingualism has contributed to the reaffirmation of ethnoculture in the school education of the village. The collected data are presented through some graphs and indirect citations of the researched subjects, evidencing as issues inherent to the reality of that school, such as teacher training, didactic-pedagogical materials, literacy process, native language and bilingualism have been Addressed in that village, and especially, sought to observe if this linguistic phenomenon evidenced there has served as ally or villain for the reinforcement of the native culture in the school environment. / A presente pesquisa teve como objeto de estudo o bilinguismo e sua contribui??o para a reafirma??o da etnocultura na educa??o escolar da aldeia ind?gena Tekrejar?tire. A referida aldeia fica situada no territ?rio ind?gena Las Casas, regi?o sudeste do estado do Par?, ? composta por ind?genas que s?o conhecidos pelo ex?nimo1 Kaiap?, mas se autodenominam os Meb?ng?kre, que significa ?os homens do lugar entre as ?guas?. Na aldeia se encontra situada a EMEF (Escola Municipal Ind?gena de Educa??o Fundamental) Kaiap?, sendo esta o l?cus desta pesquisa. Considerando as peculiaridades e necessidades que urgem quando se aborda a tem?tica da educa??o escolar ind?gena, a presente pesquisa reuniu dados acerca da presen?a da cultura Meb?ng?kre na educa??o escolar ind?gena, tendo como elemento de reafirma??o o bilinguismo, abarcando o direito de preserva??o da etnocultura e a uma educa??o diferenciada. De in?cio, ? apresentado o contexto da pesquisa descrevendo o povo Meb?ng?kre, a aldeia Tekrejar?tire e a EMEF Kaiap?. Nesse sentido elencou em linhas gerais conceitos importantes ao desenvolvimento da pesquisa, compondo a fundamenta??o te?rica assuntos como a Educa??o Escolar Ind?gena no Brasil, Educa??o Escolar Ind?gena no Par?, conceito de Etnocultura, a Cultura Meb?ng?kre incluindo-se a sua l?ngua aut?ctone, Diglossia, diversas concep??es sobre o bilinguismo, e ainda, trouxe uma apresenta??o cronol?gica do bilinguismo na educa??o escolar ind?gena ao longo de nossa hist?ria, desde o Brasil imp?rio chegando a pol?ticas atuais, como a lei 11.645/2008, que torna obrigat?rio o ensino de hist?ria afro-ind?gena, e a pol?tica de cotas para ingresso de ind?genas nas Universidades. Os percursos metodol?gicos seguidos para esta pesquisa descritivo-explorat?ria de cunho qualitativo foram pautados em an?lise documental, question?rios, entrevistas, conversas e observa??o, por meio dos quais foi poss?vel verificar como este conte?do tem sido abordado na pr?xis docente, tamb?m como o bilinguismo se revela no ambiente escolar por meio dos atores envolvidos no processo educacional da escola e ainda, como o bilinguismo tem contribu?do para a reafirma??o da etnocultura na educa??o escolar da aldeia. Os dados coletados s?o apresentados por meio de alguns gr?ficos e cita??es indiretas dos sujeitos pesquisados, evidenciando como quest?es inerentes ? realidade daquela escola, como a forma??o docente, os materiais did?tico-pedag?gicos, o processo de alfabetiza??o, a l?ngua nativa e o bilinguismo t?m sido abordados naquela aldeia, e principalmente, buscou observar se esse fen?meno lingu?stico ali evidenciado tem servido como aliado ou vil?o para o refor?o da cultura nativa no ambiente escolar.
59

CombustÃo do BiogÃs e do GÃs Natural com Elevadas ConcentraÃÃes de H2S e CO2 em Caldeira de Queimador Poroso / Combustion of Biogas and Natural Gas With High H2S and CO2 Concentrations on Porous Burner Boiler

Amanda Rafaele Serpa Camelo 23 March 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O aproveitamento do biogÃs e do gÃs natural (GN) com elevadas concentraÃÃes de diÃxido de carbono (CO2) e de sulfeto de hidrogÃnio (H2S), atravÃs de sistemas tÃrmicos de combustÃo convencionais, pode resultar em instabilidade de reaÃÃo ou, atÃ, apagamento da frente de chama, sob risco de avarias irreversÃveis para estrutura fÃsica dos equipamentos, devido aos Ãcidos corrosivos decorrentes da reaÃÃo. Ainda, altas concentraÃÃes desses contaminantes favorecem a ocorrÃncia de elevados Ãndices de gases poluentes nos produtos, a exemplo de monÃxido de carbono (CO) e hidrocarbonetos nÃo queimados (HC), dentre outros. Por essa razÃo, um estudo experimental foi realizado com base na aplicaÃÃo de uma tecnologia de combustÃo nÃo-convencional, a CombustÃo de FiltraÃÃo, a fim de lidar com esses combustÃveis de baixa qualidade. O aparato experimental empregado nessa pesquisa consiste de uma caldeira porosa de escoamento recÃproco, em que seu queimador à preenchido completamente por esferas cerÃmicas de alumina (Al2O3), formando uma matriz porosa inerte, que envolve os trocadores de calor da caldeira. O processo de queima de ambos os combustÃveis foi investigado sob condiÃÃes extremas de operaÃÃo, em termos de misturas ar-combustÃvel ultra-pobres. Como suporte para interpretaÃÃo dos fenÃmenos do processo, foi aplicado um modelo numÃrico de simulaÃÃo, que considera o mecanismo de oxidaÃÃo do metano em um meio poroso, adaptado para identificar os efeitos quÃmicos de uma alta concentraÃÃo de CO2 sobre a reaÃÃo. A influÃncia dos principais parÃmetros de operaÃÃo, razÃo de equivalÃncia e velocidade da mistura ar-combustÃvel, sob os produtos de combustÃo e sob a instabilidade de reaÃÃo foi estudada teÃrica e experimentalmente. Os resultados mostram excelente estabilidade operacional da caldeira com emissÃes ultra-baixas de CO e NOx, inferiores a 1 ppm para razÃes de equivalÃncia menores que 0,6, e com eficiÃncia de queima do H2S de mais de 99%. / The use of biogas and natural gas (GN) with high concentrations of carbon dioxide (CO2) and hydrogen sulfide (H2S) through conventional combustion thermal systems can result in reaction instability or flame front quenching, under risk of irreversible damages to the physical structure of a piece of equipments, due to corrosive acids remaining from reaction. Furthermore, high concentrations of these contaminants favor the occurrence of high pollutant levels in the products, like carbon monoxide (CO) and unburned hydrocarbon (HC), among others. Therefore, an experimental study was performed with basis on the application of a non conventional combustion technology, Filtration Combustion, in order to deal with these low-quality fuels. The experimental apparatus employed in this research consists of a reciprocal flow porous boiler, in which its burner is completely filled by ceramic spheres of alumina (Al2O3), forming an inert porous matrix, which involves boilerâs heat exchangers. The burning process of both the fuels was investigated under extreme operation conditions, in terms of ultra-lean fuel-air mixtures. As support for interpretation of the process phenomena, a numerical simulation model was applied, which takes in account the methane oxidation mechanism in a porous medium, adapted to identify the chemical effects of a high CO2-concentration on the reaction. The influence of the main operation parameters, equivalence ratio and gas flow velocity, on combustion products and on reaction stability was studied theoretically and experimentally. The results have shown excellent boiler operation stability with ultra-low emissions of NOx and CO, less than 1 ppm for equivalence ratios inferior to 0.6, and with the H2S-burning efficiency overcoming 99%.
60

O oxido nitrico na plasticidade das celulas de Schwann terminais e dos terminais nervosos da junção neuromuscular

Pereira, Elaine Cristina Leite 02 March 2005 (has links)
Orientador: Maria Julia Marques / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-04T02:52:40Z (GMT). No. of bitstreams: 1 Pereira_ElaineCristinaLeite_D.pdf: 915105 bytes, checksum: 44cd1900344bb482d9d7f8badf08d53f (MD5) Previous issue date: 2005 / Resumo: Músculos distróficos apresentam alterações no complexo distrofinaglicoproteínas, bem como ausência da enzima óxido nítrico sintase neuronal, associada a alterações na estrutura da junção neuromuscular. No presente trabalho, estudamos as respostas dos terminais nervosos e das células de Schwann terminais após lesão nervosa, na ausência de óxido nítrico (NO). Nove dias após lesão nervosa por esmagamento, 24% das junções controle (n=200) apresentaram brotamentos ultraterminais. Na ausência de NO, o mesmo foi observado em 28.5% das junções (n=217; p>0.05 comparado aos controles; X2). Quatorze dias após a lesão nervosa, todas as células de Schwann terminais observadas formaram uma rede de processos citoplasmáticos, que se estendiam para fora do sítio sináptico. Em ausência do NO, as células de Schwann terminais não apresentaram processos fora da região juncional. Estes resultados mostram que o NO está envolvido na resposta das células de Schwann terminais à lesão nervosa. Isto sugere que a sinalização molecular entre os componentes présinápticos da junção neuromuscular pode estar prejudicada nos músculos distróficos, o que poderia influenciar a inervação e sobrevivência das novas fibras musculares obtidas por terapias celulares / Abstract: Dystrophic muscles show alterations in the dystrophinglycoprotein complex and a lack of neuronal nitric oxide (NO) synthase, associated with structural changes in neuromuscular junction. In this study, we examined the nerve terminal and Schwann cell responses after a crush lesion in NOdeficient mice. Nine days after nerve crush, 24% of the control junctions (n=200) showed ultraterminal sprouts. In the absence of NO, this frequency was 28.5% (n=217; p>0.05 compared to the controls; X2 test). Fourteen days after nerve lesion, all of the Schwann cells showed an extensive network of processes away from the synaptic site, whereas in the absence of NO, Schwann cells processes failed to extend away from the endplate. These results show that NO is involved in the Schwann cell response to nerve injury. They also suggest that presynaptic molecular signaling may be impaired in dystrophic muscles, and that this could influence the innervation and survival of newly formed myofibers generated by cellmediated therapies / Doutorado / Anatomia / Doutor em Biologia Celular e Estrutural

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