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Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T13:19:50Z No. of bitstreams: 1 TES_VIRGINIA_CARLA_DE_ALMEIDA_FALCAO_COMPLETO.pdf: 3588046 bytes, checksum: 337be6be89fea4ea58787c070a072a51 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T13:19:59Z (GMT) No. of bitstreams: 1 TES_VIRGINIA_CARLA_DE_ALMEIDA_FALCAO_COMPLETO.pdf: 3588046 bytes, checksum: 337be6be89fea4ea58787c070a072a51 (MD5) / Made available in DSpace on 2017-06-30T13:20:08Z (GMT). No. of bitstreams: 1 TES_VIRGINIA_CARLA_DE_ALMEIDA_FALCAO_COMPLETO.pdf: 3588046 bytes, checksum: 337be6be89fea4ea58787c070a072a51 (MD5) Previous issue date: 2017-03-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul (FAPERGS) / Tuberculosis (TB) has become the leading global cause of death from infectious diseases. In 2015, according to WHO, 10.4 million new cases of tuberculosis worldwide have emerged. Currently the commonly used treatments are not effective against the forms of disease resistant to the most effective anti-TB drugs, and drugs with new mechanisms of action are needed. Mycobacterium tuberculosis dihydroneopterin aldolase (MtDHNA /FolB) is a folate enzyme encoded by the folB gene, which has important properties that make it a potential target for the synthesis of new antimicrobial agents. As a first step for target validation in the antimicrobial drug development pipeline, it is important to prove that the gene encoding a putative target is essential for pathogen?s viability. In this study, using site directed mutagenesis, biochemical analyzes and gene knockout experiments, we demonstrated that the folB gene is essential for the survival of Mtb, and furthermore we prove that this essentiality depends on the aldolase/epimerase activities of the MtFolB protein. The wild-type gene (wt) and the point mutants K99A and Y54F were cloned and expressed, and the corresponding recombinant proteins were purified and monitored for the activities of aldolase, epimerase and oxygenase using HPLC. In contrast to the wild-type MtFolB (wt) enzyme, both mutants had neither aldolase nor epimerase activities under the conditions tested. The Y54F mutant maintained oxygenase activity, whereas for the K99A mutant it was possible to detect oxygenase activity only in the presence of HP and GA as substrates. Knockout experiments showed that the folB gene is essential for the survival of Mtb under the conditions tested. However, unlike the wild-type copy, when the sequences encoding the K99A or Y54F mutants were used for complementation, no viable colonies were obtained, indicating that these point mutants could not rescue the cells after the folB knockout. These results indicate that aldolase and/or epimerase activities are crucial for the survival of Mtb. The construction of Mycobacterium tuberculosis folB-GFP fusion (Mtb) strains containing wild-type folB gene sequence or a deleted C-terminal mutant (folB?C), devoid of the sequence presumably necessary for anchoring the enzyme within nanocage compartments, were performed and together with other cell biology methods described in this work will be used for a better understanding of MtDHNA/FolB cellular functions and for the validation of this enzyme as a therapeutic target. / A tuberculose (TB) tornou-se a principal causa mundial de morte por doen?as infecciosas. Em 2015, de acordo com a OMS, surgiram 10,4 milh?es de novos casos de tuberculose no mundo. Atualmente os tratamentos comumente utilizados n?o s?o eficientes contra as formas da doen?a resistentes aos f?rmacos anti-TB mais eficazes, sendo necess?rios f?rmacos com novos mecanismos de a??o. A di-hidroneopterina aldolase de Mycobacterium tuberculosis (MtDHNA/FolB) ? uma enzima da via do folato, codificada pelo gene folB, que apresenta caracter?sticas importantes que a tornam um potencial alvo para s?ntese de novos agentes antimicrobianos. Neste estudo, por meio de mutag?nese s?tio-direcionada, an?lises bioqu?micas e experimentos de nocaute g?nico, demostramos que o gene folB ? essencial para a sobreviv?ncia de Mtb, e al?m disso provamos que essa essencialidade depende das atividades de aldolase/epimerase da prote?na MtFolB. O gene do tipo selvagem (wt) e os mutantes pontuais K99A e Y54F foram clonados e expressos, e as prote?nas recombinantes correspondentes foram purificadas e monitoradas para as atividades de aldolase, epimerase e oxigenase utilizando HPLC. Em contraste com a enzima MtFolB selvagem (wt), ambas as mutantes n?o apresentaram atividade de aldolase nem de epimerase nas condi??es testadas. A mutante Y54F manteve a atividade da oxigenase, enquanto que para a mutante K99A foi poss?vel detectar a atividade de oxigenase apenas na presen?a de HP e GA como substratos. Os experimentos de nocaute mostraram que o gene folB ? essencial para a sobreviv?ncia de Mtb sob as condi??es testadas. Entretanto, diferentemente da c?pia selvagem, quando as sequ?ncias que codificam os mutantes K99A ou Y54F foram utilizadas para complementa??o, n?o foram obtidas col?nias vi?veis, indicando que estes mutantes pontuais n?o poderiam resgatar as c?lulas ap?s o nocaute do gene folB. Esses resultados indicam que as atividades de aldolase e/ou epimerase s?o cruciais para a sobreviv?ncia de Mtb. A constru??o de cepas com fus?o folB-GFP de Mycobacterium tuberculosis (Mtb) que cont?m a sequ?ncia do tipo selvagem do gene folB ou um mutante com o C-terminal deletado (folB?C), desprovida da sequ?ncia supostamente necess?ria para a ancoragem da enzima dentro dos compartimentos de nanocargas, foram realizadas e juntamente com outros m?todos de biologia celular descritos neste trabalho tamb?m poder?o ser utilizados para um melhor entendimento das fun??es celulares apresentadas por MtDHNA/FolB e para valida??o dessa enzima como potencial alvo terap?utico.

Made available in DSpace on 2015-12-03T18:35:06Z (GMT). No. of bitstreams: 1 Carisa_Santos_Portela_Cristal.pdf: 1452002 bytes, checksum: 9010a4cca2dae5c4e85ccbb76c2048f8 (MD5) Previous issue date: 2009-03-20 / Business combination transactions represent a growth strategy to many firms around the world. In Brazil a major increase in the volume of business combination transactions has been observed in recent years. The publication of Law n?? 11.638/07 has served to afford conditions for Brazil to move in the direction of convergence with international standards, making the adoption of these standards, including those concerning business combination transactions, mandatory. The aim of this study is to: (i) verify whether there are significant differences between the goodwill recognized and measured before and after the adoption of IFRS for business combination transactions, by non-financial companies, listed in Spain and in the United Kingdom; and (ii) analyze the alterations of the accounting treatment prescribed by Brazilian standards with the taking effect of Law n?? 11.638/07, and to prospect probable barriers in the adoption of IFRS in Brazil, for business combination transactions. The study considers and relates the origin of the countries studied (Continental Europe x Anglo-Saxon Europe), as well as the basis of the accounting standards (rules x principles) to the differences identified in response to the adoption of IFRS. The research hypotheses were developed based on the review of literature, expecting to identify: significant alterations in the amount of goodwill recorded; more significant differences at companies listed in countries with their origin in Continental Europe; and differentiated perceptions of the impacts resulting from the adoption of IFRS by companies from different segments. To attain the objective a survey was conducted with a basis on the financial statements of 63 companies, with 35 listed in Spain and 28 in the United Kingdom, analyzing the impacts that occurred during the first year of adoption of IFRS. Statistical techniques were applied for analysis of the differences perceived with the adoption of IFRS and testing of the hypotheses defined, using: (i) Wilcoxon test aiming to evaluate the effects of the application of IFRS at the same company; (ii) Mann-Whitney test to compare the variation between the two listing countries, and; (iii) Kruskal-Wallis test for comparison among the various segments of the sample. The results obtained in the tests, besides other aspects, confirmed the existence of a significant difference in the goodwill before and after IFRS in the countries from the sample, Spain and the United Kingdom. These results and the analysis of previous studies made it possible to prospect probable barriers in the IFRS adoption process for business combination transactions at Brazilian companies. / Opera????es de combina????o de neg??cios representam uma estrat??gia de crescimento para muitas companhias ao redor do mundo. No Brasil observa-se um grande aumento no volume de opera????es de combina????o de neg??cios nos ??ltimos anos. A edi????o da Lei n?? 11.638/07 vem propiciar condi????es para que o Brasil caminhe para a converg??ncia ??s normas internacionais, tornando obrigat??ria a ado????o dessas normas, inclu??das aquelas concernentes ??s opera????es de combina????es de neg??cios. Esse estudo tem por objetivo: (i) verificar se existem diferen??as significativas entre o goodwill reconhecido e mensurado antes e depois da ado????o das IFRS para opera????es de combina????o de neg??cios, por empresas, n??o financeiras, listadas na Espanha e no Reino Unido; e (ii) analisar as altera????es do tratamento cont??bil prescrito pelas normas brasileiras com a entrada em vigor da Lei n?? 11.638/07, e prospectar prov??veis barreiras na ado????o das IFRS no Brasil, para opera????es de combina????o de neg??cios. O estudo considera e relaciona a origem dos pa??ses estudados (Europa Continental x anglo-sax??nica), bem como a base dos padr??es cont??beis (regras x princ??pios) com as diferen??as identificadas em resposta ?? ado????o das IFRS. Com base na revis??o da literatura foram desenvolvidas as hip??teses de pesquisa, sendo esperado identificar: altera????es significativas no valor do goodwill contabilizado; diferen??as mais significativas em empresas listadas em pa??ses com origem na Europa Continental; e percep????es diferenciadas dos impactos decorrentes da ado????o das IFRS por empresas de diferentes segmentos. Para atingir o objetivo foi realizada pesquisa com base nas demonstra????es financeiras de 63 empresas, sendo 35 listadas na Espanha e 28 no Reino Unido, analisando os impactos ocorridos quando do primeiro ano de ado????o das IFRS. Para an??lise das diferen??as percebidas com a ado????o das IFRS e teste das hip??teses definidas foram aplicadas t??cnicas estat??sticas utilizando: (i) teste de Wilcoxon com objetivo de avaliar os reflexos da aplica????o das IFRS na mesma empresa; (ii) teste de Mann-Whitney para comparar a varia????o entre os dois pa??ses de listagem, e; (iii) teste de Kruskal-Wallis para compara????o entre os diversos segmentos da amostra. Os resultados obtidos nos testes, entre outros aspectos, confirmaram a exist??ncia de diferen??a significativa no goodwill antes e depois das IFRS nos pa??ses da amostra, Espanha e Reino Unido. Estes resultados e a an??lise de estudos anteriores possibilitaram a prospec????o de barreiras no processo de ado????o das IFRS para opera????es de combina????o de neg??cios em empresas brasileiras.

Made available in DSpace on 2015-12-03T18:35:07Z (GMT). No. of bitstreams: 1 Joao_Paulo_Lopes_Dias.pdf: 665197 bytes, checksum: 83302d673947e04fbc148dc6387c4d01 (MD5) Previous issue date: 2007-09-13 / This paper focus on the analysis of Controlling area role in the administrative work efforts for the consolidation phase of a company merger, by identifying and evaluating specific variants in the organizational restructuring and Managerial Accounting Systems implementation or adaptation. The research is supported by bibliographic study, through concepts around the central subject. Also is based on a consolidation case study of a worldwide leader food ingredients company, in three subsidiaries located in South America. Complementarily is applied a survey with these consolidation processes participants, focusing to reinforce and validate found evidences. The case study presents elements that try to identify and measure relevancy levels of some variants, as well as, systems operational characteristics, planning and management, resources, organizational structure, organizational culture and knowledge retention, which can be part of the company consolidation processes and put on evidence the Controlling role. Finally, the deviation of the evaluation between the subsidiaries point out to critical factors which can impact the consolidation phase, as well as, merged subsidiary structure, available investments in the subsidiary and the subsidiary administration leadership in South America. / O presente trabalho procura analisar a atua????o da Controladoria na condu????o dos trabalhos administrativos na fase de consolida????o de uma empresa, identificando e avaliando as vari??veis espec??ficas presentes na reestrutura????o organizacional e implementa????o ou adequa????o de Sistemas de Informa????es Cont??beis Gerenciais (SIG). O estudo est?? embasado em pesquisa bibliogr??fica, atrav??s de conceitua????es acerca do tema central. Al??m disso, aborda estudo de caso de consolida????es de empresa l??der mundial do ramo de ingredientes para alimentos, em tr??s subsidi??rias localizadas na Am??rica do Sul. Complementarmente, aplica-se question??rio junto a participantes desse processo, na tentativa de refor??ar e validar as evid??ncias encontradas. A abordagem deste estudo de caso apresenta elementos que procuram identificar e mensurar n??veis de relev??ncia de algumas vari??veis, tais como caracter??sticas operacionais de sistemas, planejamento e gerenciamento, recursos, estrutura organizacional, cultura organizacional e reten????o de conhecimento, que podem fazer parte do processo de consolida????o de empresas e que evidenciam o papel da Controladoria. Finalmente, as varia????es de avalia????es entre as subsidi??rias apontam fatores cr??ticos que podem impactar a fase de consolida????o, tais como, estrutura da subsidi??ria incorporada, investimentos ?? disposi????o da subsidi??ria e lideran??a administrativa da subsidi??ria na Am??rica do Sul.

Made available in DSpace on 2015-12-03T18:35:29Z (GMT). No. of bitstreams: 1 Emerson_Nogueira_Sales.pdf: 3549816 bytes, checksum: f538ff67f65baa2727ce0452ad14fcab (MD5) Previous issue date: 2014-04-02 / In Brazil there were more than 6000 mergers and acquisitions (M&A) in the last ten years, these operations have been the subject of research on its effects, resulting in differing conclusions as to the consequences of these operations, especially in relation to the benefits to shareholders regarding the creation of economic value, motivating this research to seek possible theoretical explanations and empirical confirmation about F&A. Thus, the objective of this research was to investigate whether the M&A events occurred between years 2000 and 2010 in companies listed on the BM&FBOVESPA created shareholder value. Variables Tobin's Q and the EVA?? were used as proxies for value creation. Data of 83 transactions M&A were analyzed in 28 purchasing companies or resulting companies, seeking to observe the behavior of the variables after the announcement of the transaction within 36 months and for the remainder of the period (ten years) where there was data availability. Also, the data allowed comparison between results of the sample's averages and the averages of others companies listed on the BM&FBOVESPA non-sampled. The results showed symmetry with those of most previous studies demonstrating that M&A did not affect the creation of value for any of the studied variables and that the variables had negative growth over the first 36 months and had continued showing a decline when it was possible to analyze by remainder of the period, and showed symmetry with the results of the companies non-sampled / No Brasil ocorreram mais de 6 mil transa????es de fus??es e aquisi????es (F&A) nos ??ltimos dez anos, e estas opera????es tem sido alvo de pesquisas acerca dos seus efeitos, resultando em conclus??es divergentes quanto aos reflexos destas opera????es, principalmente a respeito dos benef??cios aos acionistas no tocante ?? cria????o de valor econ??mico, motivando esta pesquisa a buscar explica????es te??ricas poss??veis de confirma????o emp??rica acerca das F&A. Desta forma, o objetivo geral desta pesquisa foi investigar se as opera????es de F&A ocorridos entre 2000 a 2010 em empresas listadas na BM&FBOVESPA criaram valor para os acionistas. Foram utilizadas como proxies para cria????o de valor as vari??veis Q de Tobin e o EVA??. Foram analisados dados de 83 transa????es de F&A em 28 empresas adquirentes ou resultantes, buscando observar o comportamento das vari??veis ap??s o an??ncio das transa????es em at?? 36 meses e tamb??m para o restante do per??odo (dez anos) nos casos em que houve a disponibilidade dos dados, bem como permitiu a compara????o com os resultados das m??dias entre a amostra e as m??dias das demais empresas listadas na bolsa. Os resultados obtidos guardam simetria com aqueles da maioria dos estudos anteriores demonstrando que as F&A n??o influenciaram a cria????o de valor por nenhuma das vari??veis estudadas e que as vari??veis apresentaram varia????o negativa ao longo dos primeiros 36 meses e continuaram mostrando o decl??nio quando puderam ser acompanhados pelo restante do per??odo, e mostraram simetria com os resultados das empresas que n??o pertenciam ?? amostra

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-31T17:06:57Z No. of bitstreams: 1 2011 - Jordana Luiza Barbosa da Costa Veiga.pdf: 2017275 bytes, checksum: 953447545685588991df3f141c32d267 (MD5) / Made available in DSpace on 2016-08-31T17:06:57Z (GMT). No. of bitstreams: 1 2011 - Jordana Luiza Barbosa da Costa Veiga.pdf: 2017275 bytes, checksum: 953447545685588991df3f141c32d267 (MD5) Previous issue date: 2011-02-02 / The main objective for firms to perform a Merger&Acquisition (M&A) process is the search for a competitive advantage considered important in their strategic planning. The process of M&A can be characterized by the concentration of capital, patrimonial, organizational and societal restructuring, and cyclical movements. This dissertation, has the aim to describe and analyze the financial accounting performance of a traded corporation, registered in the stock exchange pre and post M&A performed in the year of 2005 in order to assess the value creation due to the M&A process for the shareholder of firms involved as buyer. This aim was carried out through the analysis of the data evolution, use of descriptive statistics and hypothesis test; was also analyzed the stock behavior, on stock market, by technical analysis, descriptive statistics, beta assessment, hypothesis testes and abnormal results. The analysis were carried out using the variables: earning after taxes, net sales, Ebitda, net debt, sales, earning per stock ratio, stock price, dividends payed, total assets divided by total liabilities e current ratio, presence in trading market, number of daily deals of the stock, daily turnover, closing price variation, all traded on BM&FBovespa. In order to assess the value creation for shareholders, were performed analysis in Brazilian firms on the pulp and paper industry, the chosen firms shall be traded to have all the necessary information for the assess, and shall have passed through the M&A process in 2005. Acquiring and acquired companies should also have similar size, so the process of M&As could be clearly observed in the studied variables. Only 1 target company acquired by 2 acquiring companies was chosen, which composes the universe of analysis. The study included analysis of short term, days before and after the announcement, divided into two groups 10 days before and 10 days after and 30 days before and 30 days after the announcement, and long term, periods of three years before and three years after the event. With the analysis results it was possible to observe increase on value creation for shareholders of companies involved as buyers in the process of M&A during the studied period. The variables number of daily deals of the stock, number of daily deals of the stock and daily turnover had important role on the stock-holder assess earning. It is possible to observe that the firms Suzano papel e celulose and Votoratim Celulose e Papel had substantial changes on the studied variables after the M&A process. Were observed increase on stock price, number of daily deals of the stock, number of traded stocks and daily turnover. The beta, risk indicator, after M&A, on both companies, get close to 1, improving the non-diversifiable risk of the firms. The accounting and financial parameters have showed inconclusive results probably / O objetivo principal das empresas ao recorrerem ao processo de F&A ? a busca por alguma vantagem competitiva considerada importante em seu planejamento estrat?gico. O processo de F&A pode ser caracterizado pela concentra??o de capitais, reestrutura??o patrimonial, organizacional e societ?ria, e por movimentos c?clicos. Esta disserta??o, tem por objetivo descrever e analisar o desempenho cont?bil-financeiro de sociedade an?nima de capital aberto, registrado em bolsa de valores, pr? e p?s F&A ocorrido no ano de 2005 com o intuito de avaliar a gera??o de valor decorrente do processo de F&A para os acionistas das empresas envolvidas como adquirentes, atrav?s da an?lise da evolu??o dos dados, aplica??o de estat?stica descritiva e formula??o de teste estat?stico de hip?tese; tamb?m foi realizada an?lise do comportamento das a??es, em mercado secund?rio, por meio de an?lise t?cnica, estat?stica descritiva, avalia??o do beta, teste de hip?teses e verifica??o de ganhos anormais. As an?lises foram feitas utilizando as seguintes vari?veis: lucro l?quido, receita l?quida de vendas, Ebitda, d?vida l?quida, produ??o comercializada, lucro por a??o, pre?o por a??o, dividendo pago por a??o, liquidez geral e liquidez corrente, presen?a nos preg?es, n? de neg?cios di?rio da a??o negociada, volume de neg?cios di?rio da a??o negociada, pre?o de fechamento da a??o negociada todas na BM&FBovespa. Com o intuito de avaliar a gera??o de valor para os acionistas, foram realizadas as an?lises em empresas brasileiras escolhidas do setor de papel e celulose, de capital aberto para haver disponibilidades nas informa??es necess?rias para an?lise, e que passaram pelo processo de fus?o ou aquisi??o no ano de 2005. As empresas adquirentes e adquiridas deveriam ter porte similar para que o processo de F&A pudesse ser observado com clareza nas vari?veis em estudo. Foi selecionada uma ?nica empresa alvo adquirida por 2 empresas adquirentes, que formaram o universo da an?lise. O estudo contemplou an?lises de curto prazo, dias antes e depois do an?ncio, divididos em 2 grupos 10 dias antes e 10 dias depois e 30 dias antes e 30 dias depois do an?ncio; e de longo prazo, per?odos de 3 anos antes e 3 anos ap?s o evento. Com os resultados das an?lises ? poss?vel constatar aumento na gera??o de valor para os acionistas das empresas envolvidas como adquirentes no processo de F&A, no per?odo estudado. As vari?veis n? de neg?cios, volume negociado e quantidade de a??es tiveram papel importante na avalia??o do ganho do acionista. ? poss?vel constatar que as empresas Suzano Papel e Celulose e Votorantim Celulose e Papel, tiveram altera??es substanciais nas vari?veis estudadas depois do processo de F&A. Constatou-se a valoriza??o no pre?o da a??o negociada, aumento no n? de neg?cios, na quantidade de a??es negociadas por preg?o e no volume movimentado diariamente. O beta, indicador de risco, p?s F&A, em ambas as empresas, aproximou-se de 1, aumentando o risco n?o diversific?vel das empresas. Os par?metros cont?beis-financeiros apresentaram resultados inconclusivos, provavelmente pela pequena quantidade de dados analisada e pela infu?ncia de fatores externos.

Aurora A (AurA) is an important mitotic kinase mainly studied for its involvement in cell cycle progression, centrosome maturation, mitotic spindle pole organization and bipolar spindle formation. It localizes to duplicated centrosomes and spindle microtubules (MTs) during mitosis where it regulates various factors participating in metaphase spindle formation. AurA is degraded late in mitosis suggesting that it might also have a function in anaphase. In this study we focused in understanding AurA function during anaphase in two different experimental systems. First, we kept AurA active in cycled Xenopus egg extracts and found that MTs maintained their mitotic organization longer throughout mitotic exit. We also observed chromosome segregation defects and problematic nuclear envelope formation. These observations indicate that AurA activity needs to be down-regulated for the transition from metaphase back to interphase. To get insights into the role of AurA during metaphase-anaphase transition we initially asked whether its kinase activity is still necessary for the maintenance of the metaphase spindle. We saw that the inhibition of AurA kinase activity in metaphase resulted to a collapse of the established metaphase spindle in HeLa cells. Indicating that AurA activity is necessary for the metaphase spindle maintenance. Then, we looked whether AurA kinase activity is still necessary during anaphase. We inhibited AurA at the onset of anaphase in Hela cells and found that anaphase spindles were smaller. We also observed that the MT structure responsible for anaphase spindle elongation, the central spindle, was defectively assembled and organized. Moreover, in cells where AurA was inhibited segregation of chromosomes was defective. These results indicate that AurA kinase activity is necessary for anaphase spindle elongation, central spindle assembly and organization and chromosome segregation. To understand further how AurA regulates anaphase spindle formation we looked known AurA substrates. We depleted TACC3, a known AurA substrate involved in MT formation earlier in mitosis and observed that TACC3 depletion phenocopied AurA inhibition. This indicates that TACC3 has a function in MT organization and chromosome segregation during anaphase and this function could possibly be regulated by AurA. In this study we have demonstrated that AurA activity is essential for metaphase spindle maintenance. We also found that during anaphase when AurA is either maintained active or inhibited MT organization is greatly affected and chromosome segregation is defective. Suggesting that AurA activity needs to be tightly controlled during anaphase for a correct completion of mitosis. / Aurora A (AurA) es una quinasa mitótica importante que se ha estudiado principalmente en su papel durante la progresión del ciclo celular, la maduración del centrosoma, la organización y la formación del polo y del huso mitótico. Durante la mitosis, AurA se localiza en los centrosomas duplicados y en los microtúbulos (MTs) del huso y se ha observado que regula varios factores que participan en la formación del huso mitótico. AurA se degrada al final de la mitosis indicando que pueda tener una función durante la anafase. En este estudio nos hemos centrado en la comprensión de la función de AurA durante la anafase en dos sistemas experimentales diferentes. En primer lugar, utilizando extractos de huevos de Xenopus hemos mantenido AurA activa durante la transición de metafase a anafase y hemos visto que los MTs del huso mitótico mantienen su organización durante más tiempo. También hemos observado que cuando AurA se mantiene activa existen defectos en la segregación cromosómica y la formación de la membrana nuclear. Esto indica que la actividad de AurA tiene un papel regulador sobre los MTs y la chromatina durante la transición de la metafase a la interfase. Para entender cual es la función de AurA durante la transición de metafase a anafase primero hemos estudiado si la actividad de la quinasa es necesaria para el mantenimiento del huso mitótico. Hemos visto que la inhibición de la actividad quinasa AurA resultó en el colapso del huso durante la metafase en células HeLa. Esto indica que la actividad de AurA es necesaria para el mantenimiento del huso mitótico de metafase. A continuación hemos analizamos si la actividad quinasa de AurA sigue siendo necesaria para la anafase. Para ello hemos inhibido AurA en células Hela al inicio de la anafase. En estas condiciones los husos de la anafase son más pequeños y la estructura de los MTs responsable del alargamiento del huso mitótico durante la anafase, el huso central, se organiza defectuosamente. Además, se encontraron errores durante la segregación de los cromosomas. Estos resultados indican que la actividad quinasa de AurA es necesaria para el alargamiento del huso durante la anafase y la organización y segregación cromosómica. Para entender el mecanismo de la función de AurA durante la anafase hemos estudiado a sustratos de AurA. Al estudiar TACC3 , un sustrato conocido de AurA que participa en la formación de MTs en las fase iniciales de la mitosis hemos encontrado que su eliminación de células HeLa produce el mismo fenotipo que la inhibición de AurA. Esto indica que TACC3 tiene una función en la organización de MT y la segregación de cromosomas durante la anafase y que esta función podría estar regulada por la quinasa AurA. En este estudio hemos demostrado que la actividad quinasa de AurA es esencial para el mantenimiento del huso mitótico. También hemos encontrado que durante la anafase cuando la quinasa AurA se mantiene activa o se inhibe la organización de los MTs del huso mitótico se ve muy afectada y los cromosomas se segregan defectuosamente. Por tanto los resultados de este estudio indican que la actividad quinasa de AurA está estrechamente controlada durante la anafase para el correcto cumplimiento de la mitosis.

Neurons connect to their remote targets via axons, which usually survive for the lifetime of an organism. Spatiotemporal regulation of the axonal proteome by local protein synthesis (LPS) plays a critical role in neuronal wiring and axon survival, raising the intriguing possibility that some neurological disorders involve LPS dysfunction. To visualise LPS in situ, I optimised multiple imaging techniques to investigate Netrin-1-induced translation in cultured retinal axons. Total axonal protein synthesis measured by metabolic and puromycin labelling indicates axons experience stage-dependent alterations in translation rate upon Netrin-1 stimulation. Remarkably, Netrin-1 triggers a burst of β-actin synthesis starting within 20 seconds of cue application at multiple non-repetitive sites visualised by single molecule translation imaging, an approach that allows direct visualisation of translation dynamics in response to external stimuli. Further studies have shown that local translation can occur on Rab7a-associated late endosomes, where mRNA recruitment and translation are coordinately regulated. Notably, mRNAs encoding mitochondria-related proteins are found translating on late endosomes docking in the vicinity of mitochondria, suggesting late endosomes act as ‘platforms’ for the localised synthesis of mitochondrial proteins necessary for maintaining mitochondrial integrity. Moreover, this process is affected in axons expressing the Charcot-Marie-Tooth disease type 2B (CMT2B)-related Rab7a mutants, leading to abnormal mitochondrial biogenesis and activity and compromised axon survival. Finally, attenuated de novo protein synthesis is observed in axons expressing amyotrophic lateral sclerosis (ALS)-associated fused in sarcoma (FUS) mutants and hypomethylated wild-type FUS. Live imaging reveals mislocalised mutant or hypomethylated FUS granules are transported along axons and accumulate at growth cones, possibly irreversibly trapping RNA molecules, resulting in reduced distance travelled by RNA granules in axons. Furthermore, mutant FUS expression results in defective retinal projections in vivo, highlighting the importance of RNA metabolism and local translation in axonal homeostatic mechanisms. In conclusion, aberrant translational activity in axons leads to prominent axonopathy, which recapitulates features of early stages of neurological diseases, providing the basis for novel therapeutic strategies.

Made available in DSpace on 2014-12-17T15:37:03Z (GMT). No. of bitstreams: 1 DianaGL_TESE_1-60.pdf: 3945578 bytes, checksum: b60b2a1d9ab72539c6bd59f14847deca (MD5) Previous issue date: 2011-03-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Social behavior of Guiana dolphins, Sotalia guianensis, at Pipa Beach, RN, Brazil: dynamics, sequence, breathing synchrony, and responses to dolphin watching. Social animals form groups that can range from temporary to permanent. Depending on the nature of the social relationships developed between individuals, groups present a particular social organization and the effect of these interactions shapes the activity patterns of these animals. This study investigates: (i) fission-fusion dynamics of Guiana dolphins, through the analysis of three dimensions of the social system (variation in spatial cohesion, variation in size and composition of groups), (ii) sequence, routine and behavioral stability, (iii) breathing intervals in synchronized groups and (iv) behavioral responses of the animals to dolphin watching. Systematic observations of Guiana dolphins were made from a platform located in cliffs about 25 m above sea level that surround Madeiro Bay, Pipa Beach. Sampling occurred from December 2007 to February 2009 between 0600 h and 1600 h, and the groups of Guiana dolphins were investigated according to their size (alone and group) and composition (adults, adults and juveniles, and adults and calves). According to the analysis of fission-fusion dynamics, Guiana dolphin groups frequently changed their composition, modifying their patterns of spatial grouping and cohesion every 20 minutes on average. More than 50% of the individuals maintained a distance of up to 2 m from other group members and new individuals were attracted to the group, especially during feeding, leaving it for foraging. Large groups were more unstable than small, while groups containing only adults were more stable than groups of adults and juveniles. According to the Z-score analysis to investigate the sequence and behavioral routine, lone individuals were more ! .7! ! involved in foraging and feeding, while resting was more common in groups. Foraging and feeding were more common in homogeneous groups (individuals of the same age class), while heterogeneous groups (different age classes) were often involved in socialization, displaying a broader behavioral repertoire. Foraging and resting behavior presented higher stability (continuous duration in minutes) than the other behaviors. The analysis of breathing intervals in synchronized groups showed significant differences depending on type of behavior, composition and area preference. During resting, breathing intervals were of longer duration, and groups with calves showed shorter breathing intervals than groups without calves. Lone individuals also preferred areas called corral , often used for the entrapment of fishes. The Markov chain analysis revealed behavioral changes in the presence of boats, according to the type of group composition. Groups composed of adults presented decreased resting and increased in traveling during the presence of boats. Groups of adults and juveniles showed a massive reduction of socialization, while the behavior transition probability traveling-traveling was higher in groups of adults and calves. In the presence of the boats, stability of resting was reduced by one third of its original duration and traveling more than doubled. The behavioral patterns analyzed are discussed in light of socio-ecological models concerning costs and benefits of proximity between individuals and behavioral optimization. Furthermore, significant changes in behavioral patterns indicate that Guiana dolphins, at Pipa Beach, have suffered the effects of tourism as a result of violation of rules of conduct established for the study area / Animais sociais formam grupos que podem variar de tempor?rios a permanentes. Dependendo da natureza das rela??es sociais que se desenvolvem entre os indiv?duos, grupos apresentam uma organiza??o social particular e o resultado destas intera??es moldar?o o padr?o comportamental desses animais. O presente estudo visa investigar: (i) a din?mica de fiss?o-fus?o de botos-cinza, por meio da an?lise de tr?s dimens?es do sistema social (varia??o na coes?o espacial, varia??o no tamanho e na composi??o dos grupos); (ii) a sequ?ncia, rotina e estabilidade comportamental; (iii) os intervalos respirat?rios em grupos sincr?nicos e (iv) as respostas comportamentais ao turismo de observa??o. Observa??es sistem?ticas de botos-cinza foram feitas a partir de um mirante localizado na enseada do Madeiro, praia de Pipa, a aproximadamente 25 m acima do n?vel do mar. As amostragens ocorreram entre dezembro de 2007 e fevereiro de 2009, entre 0600 h e 1600 h e os grupos de boto-cinza foram investigados de acordo com seu tamanho (sozinho e em grupo) e composi??o (adultos, adultos e juvenis, e adultos e filhotes). De acordo com a an?lise de din?mica de fiss?o-fus?o, botos-cinza mudaram sua composi??o frequentemente, modificando o tamanho dos grupos, em m?dia, a cada 20 min. Mais de 50% dos indiv?duos mantiveram dist?ncias de at? 2 m entre si e novos indiv?duos foram atra?dos ao grupo, principalmente durante alimenta??o, deixando-o durante o forrageio. Grandes grupos mostraram-se mais inst?veis do que pequenos grupos, enquanto grupos de adultos foram mais est?veis do que grupos de adultos e juvenis. De acordo com a an?lise de Z-score para investiga??o da sequ?ncia e rotina comportamental, indiv?duos sozinhos estiveram mais envolvidos em comportamentos de forrageio e alimenta??o, enquanto o repouso foi mais comum em indiv?duos em grupo. O forrageio e a alimenta??o foram mais comuns em grupos homog?neos (indiv?duos de mesma classe et?ria), enquanto grupos heterog?neos (de diferentes ! 5! ! classes et?rias) estiveram frequentemente envolvidos em socializa??o, apresentando um repert?rio comportamental mais amplo. Os comportamentos de repouso e forrageio apresentaram maior estabilidade (dura??o cont?nua em minutos), do que os demais comportamentos. A an?lise de intervalos respirat?rios em grupos sincr?nicos apontou diferen?as significativas quanto ao tipo de comportamento, composi??o e prefer?ncia de ?rea. Durante o comportamento de repouso foram observados os intervalos respirat?rios de maior dura??o, e grupos com filhotes apresentaram menores intervalos do que grupos sem filhotes. Indiv?duos sozinhos preferiram ?reas denominadas de curral , frequentemente utilizadas para o encurralamento de peixes. A partir da an?lise de cadeia de Markov, foram detectadas diferentes altera??es comportamentais na presen?a dos barcos, de acordo com o tipo de composi??o do grupo. Grupos de adultos sofreram a maior redu??o do repouso e o maior aumento do deslocamento. Adultos e juvenis apresentaram maior redu??o da socializa??o, enquanto a probabilidade de transi??o comportamental deslocamento-deslocamento foi maior em grupos de adultos e filhotes. Na presen?a dos barcos a estabilidade do repouso foi reduzida em um ter?o de sua dura??o original e o deslocamento aumentou mais do que o dobro em todas as composi??es de grupo. Os padr?es comportamentais analisados s?o discutidos ? luz dos modelos socioecol?gicos sobre custos e benef?cios da proximidade entre indiv?duos e otimiza??o comportamental. Ademais, mudan?as significativas no padr?o comportamental indicam que os botos-cinza, na praia de Pipa, v?m sofrendo os efeitos do turismo, como consequ?ncia da viola??o das normas de conduta estabelecidas para a ?rea de estudo

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-29T19:03:41Z No. of bitstreams: 1 2015 - Francine Yuriko Otsuka Rocha.pdf: 2503949 bytes, checksum: b9cea1d05fae4647a2e2459b6401ecc0 (MD5) / Made available in DSpace on 2017-06-29T19:03:41Z (GMT). No. of bitstreams: 1 2015 - Francine Yuriko Otsuka Rocha.pdf: 2503949 bytes, checksum: b9cea1d05fae4647a2e2459b6401ecc0 (MD5) Previous issue date: 2015-09-09 / CAPES / The fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici is a disease of economic importance to tomato crop (Lycopersicon esculentum Mill.) because of the losses caused in the production. This study aimed to select bacteria belonging to the genus Bacillus which have antagonistic activity to fungi present in tomato producing areas. It was obtained 193 bacterial isolates from tomato roots and stems. We performed the complete sequencing 16S rRNA subunit of 32 bacteria from the work collection using the 27F and Amp2 primers. These bacteria were randomly selected, and 20 bacteria were obtained from healthy tomato plants. The results showed a high similarity to species of the genus Bacillus: B. thuringiensis, B. megaterium, B. cereus, B. toyonensis, B. stratosphericus and Paenibacillus barcinonensis. Evaluation of the functional characteristics of the bacterial strains showed that 72% possess proteolytic activity, 78% have cellulolytic activity, 48% are able to solubilize inorganic phosphate, 42% solubilize zinc oxide and 40.8% are able to produce indols. Antagonism tests carried out in vitro showed that some bacterial strains reduced the mycelial growth of the three races of the fungus when subjected to direct method (parallel streaks). An experiment was conducted using the genotypes Debora Plus, Santa Clara Miss Brazil, Perinha and Carolina in order to select a sensitive tomato genotype to the three fungal races. The Perinha variety was the most susceptible for races 1, 2 and 3 and presented the highest percentage of fungal colonization. Thus, this variety was used in a greenhouse experiments to evaluate the antagonistic role of the Bacillus strains against three fungal races. The antagonistic activity of bacteria was assessed 15 days after transplanting of the tomato seedlings to contaminated substrate. The results showed that the B. stratosphericus strain contributed to control at least 93.25% of the damage caused by race 1, strains from species B. megaterium and B. thuringiensis controlled 100% the damage caused by race 2 and at least 67.35% of the disease caused by the race 3 of the fungus. The results suggest that some strains have the potential to control race 1, 2 and 3 of the F. oxysporum f. sp. lycopersici and have functional activities that may contribute to improving the growth of tomato plants. However, field studies are needed to confirm the role of these Bacillus species during the interaction with tomato plants grown in soil contaminated with the race 1, 2 and 3 of the fusarium wilt. / A murcha-de-fus?rio causada por Fusarium oxysporum f. sp. lycopersici ? uma doen?a de grande import?ncia econ?mica para a cultura do tomateiro (Lycopersicon esculentum Mill.) devido as perdas que ocasiona na produ??o. O presente estudo teve como objetivo selecionar bact?rias pertencentes ao g?nero Bacillus que apresentam atividade antag?nica para aplica??o em ?reas produtoras de tomate infestadas pelo fungo. Foram obtidos 193 isolados de bact?rias de ra?zes e hastes de tomateiro. Foi realizado o sequenciamento completo da subunidade 16S RNAr de 32 isolados da cole??o de trabalho, utilizando os iniciadores 27F e Amp2. Essas bact?rias foram selecionadas aleatoriamente, sendo que 20 bact?rias foram obtidas de tomateiro sadio. Os resultados mostraram uma alta similaridade das estirpes com as esp?cies do g?nero Bacillus: B. thuringiensis, B. megaterium, B. cereus, B. toyonensis, B. stratosphericus, al?m da esp?cie Paenibacillus barcinonensis. Testes para avaliar as caracter?sticas funcionais das estirpes bacterianas in vitro mostraram que 72% das estirpes possuem atividade proteol?tica, 78% possuem atividade celulol?tica, 48% solubilizam fosfato inorg?nico, 42% solubilizam zinco e 40,8% s?o capazes de produzir indol. Testes de antagonismo realizados in vitro mostraram que algumas estirpes bacterianas retardaram ou reduziram o crescimento micelial das tr?s ra?as do fungo quando submetidos ao m?todo de a??o direta (estrias paralelas). Com o objetivo de selecionar um gen?tipo de tomateiro sens?vel as tr?s ra?as do fungo, foi instalado um experimento utilizando os gen?tipos D?bora Plus, Santa Clara Miss Brasil, Perinha e Carolina. A variedade Perinha foi a mais suscet?vel as ra?as 1, 2 e 3 j? que apresentou um maior percentual de coloniza??o do fungo. A atividade antag?nica das bact?rias foi avaliada 15 dias ap?s o transplantio das mudas de tomate da variedade Perinha para o substrato contaminado. Os resultados mostraram que a estirpe da esp?cie B. stratosphericus controlou cerca de 93,25% das plantas crescidas na presen?a da ra?a 1 do fungo. J? as esp?cies B. megaterium e B. thuringiensis controlaram 100% da doen?a das plantas de tomateiro cultivadas em substrato com a ra?a 2 e de 67,35% das plantas cultivadas em substrato com a ra?a 3 do fungo. Os resultados obtidos sugerem que algumas estirpes possuem potencial para controle de F. oxysporum f. sp. lycopersici ra?a 1, 2 e 3 e possuem atividades funcionais que podem contribuir para a melhoria do crescimento das plantas de tomateiro cultivadas em ?reas infestadas com o fungo. Entretanto, estudos em campo s?o necess?rios para confirmar o papel dessas esp?cies de Bacillus na intera??o com plantas de tomateiro cultivadas na presen?a das ra?as 1, 2 e 3 da murcha de fus?rio.