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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.
41

Caracterização bioquímica da Beta-Xilosidase II de Caulobacter crescentus visando a degradação da biomassa lignocelulósica para aplicações biotecnológicas / Biochemical characterization of beta-xylosidase ii from caulobacter crescentus concentrates on lignocellulosic biomass degradation for biotechnological applications

Silva, Amanda Alves 07 December 2015 (has links)
Made available in DSpace on 2017-05-12T14:36:23Z (GMT). No. of bitstreams: 1 DISSERTACAO AMANDA ALVES MESTRADO EM CIENCIAS FARMACEUTICAS _UNIOESTE 2015.pdf: 10598736 bytes, checksum: 51f0f3eb83858fee62392b7892930766 (MD5) Previous issue date: 2015-12-07 / Lignocellulosic biomass are the raw material most abundant and promising as a natural and renewable resource. These plant materials are complex carbohydrate polymer composed mainly of cellulose, hemicellulose and lignin, which are linked by covalent bonds and can be transformed into value-added products, such as biofuels. The degradation of lignocellulosic material is made mainly from enzymes produced by microorganisms such as filamentous fungi, yeast and bacteria. Ethanol production from agricultural residues, based on the enzymatic hydrolysis, it takes basically four stages: production of enzymes, pretreatment, enzymatic hydrolysis and fermentation. Pretreatment is a work that will break the lignin cellulose complex, reducing the degree of crystallinity of the cellulose and increase the porosity of the material, by increasing the surface area of the biomass. However, pre-treatment products can generate inhibitors which include phenolic and other aromatic, aliphatic acids, aldehydes, furans, inorganic ions. The fermentation and simultaneous saccharification is an important approach for producing cellulosic or ethanol of second generation, where the enzymatic hydrolysis of cellulose and fermentation are simultaneously carried out in the same reactor, in order to obtain ethanol at a high rate and decrease formation of inhibitor compounds. Enzymatic hydrolysis requires, first, that the lignocellulosic biomass is pretreated to increase access to enzymatic attack, so that later the cellulose is broken down by cellulase action. Xylanases include the group of enzymes responsible for the hydrolysis of xylan, the major constituent of hemicellulose. The key enzymes involved in this process are β-1,4-endoxylanase and β-D-xylosidase. Endoxylanase cleave glycosidic linkages of the main chain of xylan releasing xylo-oligosaccharides, which are used by β-xylosidase to produce monomers of xylose. The alfaproteobacteria Caulobacter crescentus is non pathogenic, Gram negative, mainly found in aquatic environments and on many types of soils. This bacterium has about seven genes directly associated with xylan degradation and five of them encoding β-xylosidases. To date, there are only three studies on the β-xylosidase II from C. crescentus. The first characterization of this enzyme showed that it is capable of hydrolyzing substrates such as xylobiose, xylotriose and xilopentose whose optimum pH is 6 and optimum temperature is 55°C, although it is stable at 50°C, which shows a thermotolerance, indicating strong enough to be used in different biotechnological applications. The stability and reusability of enzymes are of fundamental importance, since they reflect significantly on the cost of the final product, and one way to achieve this is with the immobilization of enzymes, consisting of confinement thereof in a matrix or support, which can be inert polymers or inorganic materials, so that its catalytic activity is retained and the enzyme can be used repeatedly and continuously. In the present report, it was found that the β-xylosidase II (CcXynB2) of Caulobacter crescentus increased by 62% of its activity in 5 mM KCl probably as a consequence of a positive role of K+ ions. CCxynB2 was measured against various compounds described as inhibitors of hydrolysis and fermentation of lignocellulosic biomass and showed 61% more tolerant incubation with ethanol (200 mM) at 37 °C for 48 h in the absence of alcohol. The specific activities of CcXynB2 were evaluated in the presence of 10mM phenol or galacturonic acid, 100 mM hydroxymethylfurfural or ferulic acid, 1 mM acetic acid, 200 mM arabinose, glucose or xylose and it was found that were equal (100%) or much higher than the values obtained in the total absence of these compounds after 48 h. When the inhibitors were used in combination, the CcXynB2 retained 67% of its initial activity after testing at 37°C during 48 h. The enzymatic hydrolysis of hemicellulose from corncob was conducted with CcXynB2 alone or in synergism with xylanase and commercial β-glycosidase, which were more efficient in performed the saccharification of hemicellulose from 37-50 °C. The immobilized CcXynB2 in mobile phase resin led to a protective effect of specific activity, which was proportionally parallel to decreased temperatures (60 to -20°C). The data presented here indicate that CcXynB2 is promising and has potential to work in simultaneous saccharification and fermentation processes for cellulosic ethanol production. To our knowledge, is the first time that similar results are reported in the literature to bacterial β-xylosidases. Thus, this work contribute positively by providing essential information to improve the use of β-xylosidase II of Caulobacter crescentus. / Biomassas lignocelulósicas constituem a matéria-prima mais abundante e promissora como recurso natural e renovável. Esses materiais vegetais são polímeros de carboidratos complexos compostos basicamente por celulose, hemicelulose e lignina, que estão unidos entre si por ligações covalentes e podem ser convertidos em produtos de valor agregado, como os biocombustíveis. A degradação dos materiais lignocelulósicos é feita a partir de enzimas produzidas principalmente por micro-organismos como fungos filamentosos, leveduras e bactérias. Para obter etanol a partir de resíduos agroindustriais, baseando-se na hidrólise enzimática, são necessárias, basicamente, quatro etapas: produção de enzimas, pré-tratamento, hidrólise enzimática e fermentação. O pré-tratamento é o processo que irá dissociar o complexo lignina-celulose, reduzir o grau de cristalinidade da celulose e aumentar a porosidade dos materiais, através do aumento da área superficial da biomassa. No entanto, o pré-tratamento pode gerar produtos inibidores, que incluem compostos fenólicos e outros aromáticos, ácidos alifáticos, aldeídos, furanos, íons inorgânicos. A fermentação e sacarificação simultânea é uma estratégia importante para a produção de etanol celulósico ou de segunda geração, onde a hidrólise enzimática da celulose e a fermentação são desenvolvidas simultaneamente no mesmo reator, com o intuito de obter etanol em altas taxas e diminuir a formação de compostos inibidores. A hidrólise enzimática necessita, primeiramente, que a biomassa lignocelulósica seja pré-tratada para aumentar o acesso ao ataque enzimático, para que posteriormente a celulose seja quebrada pela ação de celulases. As xilanases compreendem o grupo de enzimas responsáveis pela hidrólise do xilano, principal constituinte da hemicelulose. As principais enzimas envolvidas nesse processo são β-1,4-endoxilanase e a β-D-xilosidase. Endoxilanases clivam as ligações glicosídicas da cadeia principal do xilano liberando xilo-oligossacarídeos, que são utilizados pelas β-xilosidases para liberar xilose. A alfaproteobactéria Caulobacter crescentus é não patogênica, Gram negativa, encontrada principalmente em ambientes aquáticos e em muitos tipos de solos. Essa bactéria apresenta cerca de sete genes envolvidos diretamente na degradação do xilano, sendo que cinco deles codificam para β-xilosidases. Até o momento, existem apenas três trabalhos sobre a β-xilosidase II de C. crescentus. A primeira caracterização da enzima mostrou que esta é capaz de hidrolisar substratos como xilobiose, xilotriose e xilopentose, cujo pH ótimo é 6 e temperatura ótima é 55ºC, embora seja mais estável em 50ºC, o que demonstra uma modesta termotolerância, indicando ser suficientemente resistente para diferentes aplicações biotecnológicas. A estabilidade e a possibilidade de reutilização de enzimas são de fundamental importância, pois refletem significativamente no custo do produto final, e uma forma de conseguir isso é com a imobilização de enzimas, que consiste no confinamento da mesma em uma matriz ou suporte, que podem ser polímeros inertes ou materiais inorgânicos, de modo que sua atividade catalítica fique retida e a enzima possa ser usada repetidamente e continuamente. No presente trabalho, verificou-se que a β-xilosidase II (CcXynB2) de Caulobacter crescentus aumentou 62% da sua atividade em 5 mM de KCl provavelmente em consequência de um papel positivo dos íons K+. CcXynB2 foi avaliada frente a diferentes compostos descritos como inibidores do processo de hidrólise e fermentação da biomassa lignocelulósica e mostrou-se 61% mais tolerante a incubação com etanol (200 mM) a atividades específicas da CcXynB2 foram avaliadas na presença de 10 mM fenol ou ácido galacturônico, 100 mM de hidroximetilfurfural ou ácido ferúlico, 1 mM de ácido acético, 200 mM de arabinose, glicose ou xilose, e verificou-se que foram iguais (100%) ou muito superiores aos valores obtidos na ausência total destes compostos após 48 h. Quando os inibidores foram usados em associação, a CcXynB2 reteve 67% da sua atividade inicial após 48 h de ensaio a 37ºC. A hidrólise enzimática da hemicelulose de sabugo de milho foi conduzida com CcXynB2 isoladamente ou em sinergismo com xilanase e β-glicosidase comerciais, as quais foram mais eficientes em sacarificar a hemicelulose entre 37-50ºC. A imobilização da CcXynB2 em resina de fase móvel levou a um efeito protetor da atividade específica, que ocorreu de forma paralela à diminuição de temperatura (60 a -20ºC). Os dados apresentados aqui indicam que a CcXynB2 é promissora e possui potencial para atuar em processos de sacarificação e fermentação simultânea para produção de etanol celulósico. Segundo nosso conhecimento, é a primeira vez que resultados similares são relatados na literatura para β-xilosidases bacterianas. Dessa forma, este trabalho pode contribuir positivamente, fornecendo informações fundamentais para aprimorar o uso da β-xilosidase II de Caulobacter crescentus
42

Caracterização bioquímica da Beta-Xilosidase II de Caulobacter crescentus visando a degradação da biomassa lignocelulósica para aplicações biotecnológicas / Biochemical characterization of beta-xylosidase ii from caulobacter crescentus concentrates on lignocellulosic biomass degradation for biotechnological applications

Silva, Amanda Alves 07 December 2015 (has links)
Made available in DSpace on 2017-07-10T13:59:26Z (GMT). No. of bitstreams: 1 DISSERTACAO AMANDA ALVES MESTRADO EM CIENCIAS FARMACEUTICAS _UNIOESTE 2015.pdf: 10598736 bytes, checksum: 51f0f3eb83858fee62392b7892930766 (MD5) Previous issue date: 2015-12-07 / SIM(não especificado) / Lignocellulosic biomass are the raw material most abundant and promising as a natural and renewable resource. These plant materials are complex carbohydrate polymer composed mainly of cellulose, hemicellulose and lignin, which are linked by covalent bonds and can be transformed into value-added products, such as biofuels. The degradation of lignocellulosic material is made mainly from enzymes produced by microorganisms such as filamentous fungi, yeast and bacteria. Ethanol production from agricultural residues, based on the enzymatic hydrolysis, it takes basically four stages: production of enzymes, pretreatment, enzymatic hydrolysis and fermentation. Pretreatment is a work that will break the lignin cellulose complex, reducing the degree of crystallinity of the cellulose and increase the porosity of the material, by increasing the surface area of the biomass. However, pre-treatment products can generate inhibitors which include phenolic and other aromatic, aliphatic acids, aldehydes, furans, inorganic ions. The fermentation and simultaneous saccharification is an important approach for producing cellulosic or ethanol of second generation, where the enzymatic hydrolysis of cellulose and fermentation are simultaneously carried out in the same reactor, in order to obtain ethanol at a high rate and decrease formation of inhibitor compounds. Enzymatic hydrolysis requires, first, that the lignocellulosic biomass is pretreated to increase access to enzymatic attack, so that later the cellulose is broken down by cellulase action. Xylanases include the group of enzymes responsible for the hydrolysis of xylan, the major constituent of hemicellulose. The key enzymes involved in this process are β-1,4-endoxylanase and β-D-xylosidase. Endoxylanase cleave glycosidic linkages of the main chain of xylan releasing xylo-oligosaccharides, which are used by β-xylosidase to produce monomers of xylose. The alfaproteobacteria Caulobacter crescentus is non pathogenic, Gram negative, mainly found in aquatic environments and on many types of soils. This bacterium has about seven genes directly associated with xylan degradation and five of them encoding β-xylosidases. To date, there are only three studies on the β-xylosidase II from C. crescentus. The first characterization of this enzyme showed that it is capable of hydrolyzing substrates such as xylobiose, xylotriose and xilopentose whose optimum pH is 6 and optimum temperature is 55°C, although it is stable at 50°C, which shows a thermotolerance, indicating strong enough to be used in different biotechnological applications. The stability and reusability of enzymes are of fundamental importance, since they reflect significantly on the cost of the final product, and one way to achieve this is with the immobilization of enzymes, consisting of confinement thereof in a matrix or support, which can be inert polymers or inorganic materials, so that its catalytic activity is retained and the enzyme can be used repeatedly and continuously. In the present report, it was found that the β-xylosidase II (CcXynB2) of Caulobacter crescentus increased by 62% of its activity in 5 mM KCl probably as a consequence of a positive role of K+ ions. CCxynB2 was measured against various compounds described as inhibitors of hydrolysis and fermentation of lignocellulosic biomass and showed 61% more tolerant incubation with ethanol (200 mM) at 37 °C for 48 h in the absence of alcohol. The specific activities of CcXynB2 were evaluated in the presence of 10mM phenol or galacturonic acid, 100 mM hydroxymethylfurfural or ferulic acid, 1 mM acetic acid, 200 mM arabinose, glucose or xylose and it was found that were equal (100%) or much higher than the values obtained in the total absence of these compounds after 48 h. When the inhibitors were used in combination, the CcXynB2 retained 67% of its initial activity after testing at 37°C during 48 h. The enzymatic hydrolysis of hemicellulose from corncob was conducted with CcXynB2 alone or in synergism with xylanase and commercial β-glycosidase, which were more efficient in performed the saccharification of hemicellulose from 37-50 °C. The immobilized CcXynB2 in mobile phase resin led to a protective effect of specific activity, which was proportionally parallel to decreased temperatures (60 to -20°C). The data presented here indicate that CcXynB2 is promising and has potential to work in simultaneous saccharification and fermentation processes for cellulosic ethanol production. To our knowledge, is the first time that similar results are reported in the literature to bacterial β-xylosidases. Thus, this work contribute positively by providing essential information to improve the use of β-xylosidase II of Caulobacter crescentus. / Biomassas lignocelulósicas constituem a matéria-prima mais abundante e promissora como recurso natural e renovável. Esses materiais vegetais são polímeros de carboidratos complexos compostos basicamente por celulose, hemicelulose e lignina, que estão unidos entre si por ligações covalentes e podem ser convertidos em produtos de valor agregado, como os biocombustíveis. A degradação dos materiais lignocelulósicos é feita a partir de enzimas produzidas principalmente por micro-organismos como fungos filamentosos, leveduras e bactérias. Para obter etanol a partir de resíduos agroindustriais, baseando-se na hidrólise enzimática, são necessárias, basicamente, quatro etapas: produção de enzimas, pré-tratamento, hidrólise enzimática e fermentação. O pré-tratamento é o processo que irá dissociar o complexo lignina-celulose, reduzir o grau de cristalinidade da celulose e aumentar a porosidade dos materiais, através do aumento da área superficial da biomassa. No entanto, o pré-tratamento pode gerar produtos inibidores, que incluem compostos fenólicos e outros aromáticos, ácidos alifáticos, aldeídos, furanos, íons inorgânicos. A fermentação e sacarificação simultânea é uma estratégia importante para a produção de etanol celulósico ou de segunda geração, onde a hidrólise enzimática da celulose e a fermentação são desenvolvidas simultaneamente no mesmo reator, com o intuito de obter etanol em altas taxas e diminuir a formação de compostos inibidores. A hidrólise enzimática necessita, primeiramente, que a biomassa lignocelulósica seja pré-tratada para aumentar o acesso ao ataque enzimático, para que posteriormente a celulose seja quebrada pela ação de celulases. As xilanases compreendem o grupo de enzimas responsáveis pela hidrólise do xilano, principal constituinte da hemicelulose. As principais enzimas envolvidas nesse processo são β-1,4-endoxilanase e a β-D-xilosidase. Endoxilanases clivam as ligações glicosídicas da cadeia principal do xilano liberando xilo-oligossacarídeos, que são utilizados pelas β-xilosidases para liberar xilose. A alfaproteobactéria Caulobacter crescentus é não patogênica, Gram negativa, encontrada principalmente em ambientes aquáticos e em muitos tipos de solos. Essa bactéria apresenta cerca de sete genes envolvidos diretamente na degradação do xilano, sendo que cinco deles codificam para β-xilosidases. Até o momento, existem apenas três trabalhos sobre a β-xilosidase II de C. crescentus. A primeira caracterização da enzima mostrou que esta é capaz de hidrolisar substratos como xilobiose, xilotriose e xilopentose, cujo pH ótimo é 6 e temperatura ótima é 55ºC, embora seja mais estável em 50ºC, o que demonstra uma modesta termotolerância, indicando ser suficientemente resistente para diferentes aplicações biotecnológicas. A estabilidade e a possibilidade de reutilização de enzimas são de fundamental importância, pois refletem significativamente no custo do produto final, e uma forma de conseguir isso é com a imobilização de enzimas, que consiste no confinamento da mesma em uma matriz ou suporte, que podem ser polímeros inertes ou materiais inorgânicos, de modo que sua atividade catalítica fique retida e a enzima possa ser usada repetidamente e continuamente. No presente trabalho, verificou-se que a β-xilosidase II (CcXynB2) de Caulobacter crescentus aumentou 62% da sua atividade em 5 mM de KCl provavelmente em consequência de um papel positivo dos íons K+. CcXynB2 foi avaliada frente a diferentes compostos descritos como inibidores do processo de hidrólise e fermentação da biomassa lignocelulósica e mostrou-se 61% mais tolerante a incubação com etanol (200 mM) a atividades específicas da CcXynB2 foram avaliadas na presença de 10 mM fenol ou ácido galacturônico, 100 mM de hidroximetilfurfural ou ácido ferúlico, 1 mM de ácido acético, 200 mM de arabinose, glicose ou xilose, e verificou-se que foram iguais (100%) ou muito superiores aos valores obtidos na ausência total destes compostos após 48 h. Quando os inibidores foram usados em associação, a CcXynB2 reteve 67% da sua atividade inicial após 48 h de ensaio a 37ºC. A hidrólise enzimática da hemicelulose de sabugo de milho foi conduzida com CcXynB2 isoladamente ou em sinergismo com xilanase e β-glicosidase comerciais, as quais foram mais eficientes em sacarificar a hemicelulose entre 37-50ºC. A imobilização da CcXynB2 em resina de fase móvel levou a um efeito protetor da atividade específica, que ocorreu de forma paralela à diminuição de temperatura (60 a -20ºC). Os dados apresentados aqui indicam que a CcXynB2 é promissora e possui potencial para atuar em processos de sacarificação e fermentação simultânea para produção de etanol celulósico. Segundo nosso conhecimento, é a primeira vez que resultados similares são relatados na literatura para β-xilosidases bacterianas. Dessa forma, este trabalho pode contribuir positivamente, fornecendo informações fundamentais para aprimorar o uso da β-xilosidase II de Caulobacter crescentus
43

Assimilation, social network sites and Asian stereotype : understanding Chinese-American teenagers in Austin

Huang, Gejun 14 October 2014 (has links)
Given the increasing number of younger immigrants from China, we have noticed diversified performances of Chinese-American teenagers based on the age they come to the U.S. This thesis thus examines three specific aspects—assimilation, social network site (SNS) use, and reaction to Asian stereotype—of Chinese-American teenagers living in Austin, regarding intraethnic differences between and among different clusters of this cohort as the second generation immigrant. By employing semi-structured interviews conducted with teenagers who have respective immigrant history and family background, a wide array of patterns about assimilation, SNS use, and reaction to Asian stereotype are traced and analyzed alongside demonstrating outlines and traits in terms of different generation clusters (1.25ers, 1.5ers, 1.75ers and 2.0ers). A total of ten Chinese-American teenagers, aged from 15 to 18, are recruited and interviewed through snowball approach, allowing for the surface of intraethnic variations on the aforementioned aspects. Preliminary discussions are made to tease out how these three aspects are intertwined. / text
44

Does parental origin reflect the labor market outcome? : Study of differences between native Swedes and second generation immigrants

Ekblom, Jens January 2016 (has links)
Sweden is a country with an increasing foreign born population, where more and more people growing up with two parents born outside of Sweden. In this paper I examine the different labor market outcome for native Swedes and the six largest groups of second generation immigrants in the ages 30-39 years. The analysis is divided in two part where the first examining the level of gainful employment and the second the distribution in line of work. By using data from population register there was possible to perform detailed analysis. The gainfully employment rate are lower for the different groups of second generation immigrants. Unlike earlier studies regarding employment differences depending on parental origin, there are however not as distinct pattern of ethnic penalties. The result regarding line of work from the second part of the analysis show that some groups of second generation have a higher risk of being in less-qualified jobs after controlling for education, personal- and parental variables.
45

Socialisation effects on potential inheritors' career orientation and succession in South Asian family businesses in Scotland

Sheikh, Shariq Zia January 2014 (has links)
The aim of this thesis is to understand the phenomenon of succession among South Asian small family businesses based in Scotland. It explores the reluctance of the younger generation towards choosing family businesses as their careers. The thesis aims to understand the career orientation of potential inheritors leading to succession or a lack of succession by understanding their socialisation process. Thereby it integrates the literatures of family business succession, socialisation and career development. The thesis presents a conceptual framework of the nature/interaction of factors such as personal factors, familial, cultural, those pertaining to the economic environment, education and family business factors, its effects on Career Orientation and choice of Career pathways leading to succession or not among ethnic minority small family enterprises. This is presented in the context of the changing economic, social and cultural environment in which these businesses operate. Research questions focus on understanding the process of socialisation in a dual cultural context i.e. Asian as well as British, its effects on career orientations and most importantly on Asian family business succession. Although family business succession is presented as a widely researched subject area, this thesis particularly highlights the gaps arising due to an understanding that has specifically developed in the past from the founder or incumbent owners’ perspective. This thesis researched from the perspective of the potential inheritor, to understand the process of socialisation and its effects on career orientation leading to succession in Asian family businesses and contributes to fulfilling the theoretical gap in the literature. The focus of the empirical research is the Scotland based Asian community owned small retail businesses that are family owned. Succession is important for continuity and failure to succeed are seen to have adverse effects on the long term inter-generational continuity. At the same time succession among the second generation is looked at as a career choice which is influenced by a career decision making process. Hence a conceptual framework is necessary that looks at the concepts of socialisation, career decision making and succession together. Having the family and business interdependent in this complex system, it is not just the economic environment that shapes these factors, but also the dynamics within the family, society and community pressures, religion, a conflicting multigeneration perspective on business, culture and life in the UK. These demand a qualitative methodology, using personal interviews with both old and young generations and key informants as well as informal conversations with members of the community for sample selection, data collection and theory generation. The data collection process was guided by the newly formulated theoretical framework. Data was categorised as per themes from the framework and coded into categories in order to understand the process of socialisation and career orientation. This was then used to draw out the various career pathways that the individuals selected providing an understanding of reluctance towards joining the family business. The findings revealed that integrating the concepts of socialisation, career development and orientation provided a greater understanding of the process of decision making about succession among potential inheritors from Asian small family businesses. However, a number of other themes emerged from the findings, these are an emphasis on work-life balance as key to decision making. In addition, other themes that emerged were increased desire for paternal bonding, status and prestige from chosen careers, boundedness due to Asian stereotype, and parental or societal pressure and expectations. Moreover, trans-generational entrepreneurial continuity emerged as an important theme in which the older as well as the younger generation realised alternatives to continuing the existing family business and that true succession possibly is the transfer of entrepreneurial skills and abilities, something that the older generation developed and utilised when starting their own businesses as migrants. The thesis makes a contribution to the theoretical understanding of succession among South Asian family businesses. The findings emphasise the understanding of the succession process as a career decision making process particularly when looked at from the potential inheritors’ perspective. It also contributes to the socialisation literature by developing the multi-dimensional understanding of bi-cultural identity formation due to the dual impact of factors such as culture, religion, peers, family and broader society. This thesis also makes recommendations to policy by suggesting a conscious shift in policy orientation from the traditional first generation migrant to the young generation British Asian child of a migrant who due to their different socialisation has unique needs and orientations. The thesis recommends, on the basis of findings, for policy to be sensitive to the needs of the younger generation and for it to be focused on developing self-employment among this new generation of Asians.
46

The Rumi cultural events centre - design for Winnipeg's second generation Muslims

Abdullaev, Umidjon 15 April 2016 (has links)
The Rumi Cultural Events Centre explores how the built environment can reflect a cultural phenomenon such as the evolution of Muslim communities in Western secular society of Canada. The centre has been designed for second generation Muslims, whose simultaneous exposure to religious and secular values change their outlook on religion and culture (Greif, 2007; Amor, 2006, Hadjiyanni, 2007; Kohut, Allan & Wike, 2006; Akyol, 2011; Mandaville, 2001; Distin, 2001). They reinvent the notion of Islam in a secular context, and create a synthesis that embodies religiosity, culture and secularism. The Rumi Centre is a new typology of space that emerges from a need to synthesize the new Muslim identity and values in order to create a non-traditional cultural environment. The Rumi Centre is not a religious institution. It is a culturally appropriate and contemporary events venue where forward looking and traditional Muslims come together with the local community. The centre’s design language reflects the attitude of Muslims who embrace modernity and secular lifestyle but remain true to their culture. / May 2016
47

Um coração que ainda bate após Auschwitz: um estudo de caso sobre o Holocausto / A heart that still beats after Auschwitz: a case study

Rocha, Thaís de Santis 12 August 2016 (has links)
A presente investigação tem como objetivo estabelecer a relevância da relação dos descendentes do Holocausto com a memória desse evento através da análise da obra Meu coração Ferido, escrita por Martin Doerry. Essa obra retrata a trajetória de uma mulher judia entre 1900 e 1944, mostrando como as medidas nazistas alteraram seu cotidiano, incluindo cartas escritas no período no qual esteve confinada em um campo de concentração. Ela possui um destaque dentro da literatura atual devido a sua narrativa, que mescla textos produzidos na época com a contextualização dos fatos feita pelo autor. Pretende-se apontar como ocorre a transferência desse tipo de memória com descendentes de vítimas do holocausto, mostrando como as gerações posteriores convivem com esse tipo de memória e escrevem sobre a mesma. / This research aims to analyze the Holocaust representation possibilities from a biography, \"Meu Coração Ferido,\" written by Martin Doerry, and seek to understand how occur the Nazi understanding of processes during installation and the prospect of separated families war, using as source letters exchanged in the period. During the writing process of this work, the author\'s purpose was to understand how his grandmother, Lilli Jahn, differed from others who suffered under Nazism, in their struggle for the liberation of the children and their peculiar character and the preservation and protection of the family. The research focuses on the study of how the descendants understand the Holocaust through in their search for an identity for many years silenced.
48

Produção heteróloga, caracterização biofísica e estrutural de xilose isomerases visando potenciais aplicações na fermentação pentoses / Heterologous production, structural and biophysical characterization of xylose isomerases aiming potential applications in pentoses fermentation

Reis, Caio Vinicius dos 08 February 2017 (has links)
Fazemos parte de um cenário mundial em que o esgotamento das fontes de energias fósseis atrelado à poluição gerada por esse uso, preocupam os diferentes setores do comércio, da indústria, do governo e das instituições em defesa do meio ambiente. Nesse sentido, a busca por novas fontes energéticas renováveis tem dirigido diversas pesquisas, além de drenar bilhões de dólares em investimentos. Uma das linhas de pesquisa mais importantes é a da produção do etanol de segunda geração (2G), um etanol produzido a partir dos resíduos gerados na produção do etanol de primeira geração. No caso do Brasil, esses resíduos compreendem principalmente a palha e o bagaço de cana-de-açúcar; essa biomassa é formada majoritariamente por celulose (∼45%), hemicelulose (∼25%) e lignina (∼20), e sua hidrólise envolve pré-tratamentos adequados e uso de enzimas que agem especificamente em seus alvos. Dessa forma, a produtividade de etanol aumenta, sem necessariamente ampliar áreas de cultivo. Essa vertente é muito promissora, porém os custos ainda são relativamente altos e a aplicabilidade depende bastante de adaptações do setor industrial e aprimoramentos na produção em si (atividade específica das enzimas e sua ação sinérgica). O objetivo principal deste projeto é reconhecer e mapear as bases moleculares que comandam a atividade da enzima xilose isomerase (XI), que converte xilose (presença majoritária na hemicelulose) em xilulose, possibilitando a utilização desta por Saccharomyces cerevisiae (já que a xilose não é fermentescível), para obtenção do etanol de segunda geração como produto final. Para isso, foi realizada uma busca extensiva de genes de diversos microrganismos, que codifiquem para XI, e que essas ainda não possuam estruturas resolvidas publicadas. A maioria das ORFs (Open Reading Frame, do inglês), ou regiões codificadoras, foram amplificadas, clonadas em vetores específicos e transformadas em bactérias Escherichia coli Rosetta (DE3). Parte dessas cepas transformadas resultaram na produção da XI de interesse. Com isso, foi possível obter cristais e iniciar a resolução de estruturas cristalográficas. Esses resultados foram cruzados e correlacionados com os de atividade enzimática, cinética química e estabilidade térmica, fornecendo boa perspectiva para o entendimento das bases moleculares que regem a atividade xilose isomerásica. / We are part of a world scenario in which the depletion of fossil energy sources linked to the pollution generated by this use, concern the different sectors of commerce, industry, government and institutions in defense of the environment. In this regard, the search for new renewable energy sources has headed many researches, besides generating billions of dollars in investments. One of the most important research lines is the production of second generation ethanol (2G), an ethanol produced from the waste generated in the production of the first generation one. In the case of Brazil, these residues mainly include sugar cane straw and bagasse. This biomass is mostly composed of cellulose (∼45%), hemicellulose (∼25%) and lignin (∼20), and its hydrolysis involves adequate pre-treatments and the use of enzymes that specifically act on their targets. In this way, ethanol productivity increases without necessarily expanding growing areas. This aspect is very promising, but the costs are still relatively high and the applicability badly depends on adaptations of the industrial sector and improvements in the production itself (specific activity of the enzymes and their synergistic action with others). The main goal of this project is to recognize and map the molecular bases that control the activity of the enzyme xylose isomerase (XI), which converts xylose (the mostly present carbohydrate in hemicellulose) into xylulose, allowing its use by Saccharomyces cerevisiae (since xylose is not fermentable), to obtain the second generation ethanol as final product. To reach this, an extensive search of genes of several microorganisms, that code for XI, and still do not have solved high resolution structures published are carried out. Most ORFs (Open Reading Frames) were amplified, cloned into specific vectors and transformed into Escherichia coli Rosetta (DE3) bacteria. Some of these transformed strains leaded to the production of XI of interest. Furthermore, it was possible to obtain protein crystals and to start trying to solve crystallographic structures. These results were cross - checked and correlated with those of enzymatic activity, chemical kinetics and thermal stability, providing a good perspective for understanding the molecular bases which govern isomerase activity.
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Variabilidade genética e estrutura haplotípica do gene kir2dl4 avaliada em uma amostra brasileira

Weiss, Emiliana January 2019 (has links)
Orientador: Erick da Cruz Castelli / Resumo: O gene KIR2DL4 codifica um importante receptor de células Natural Killer (NK). O único ligante de KIR2DL4 conhecido é a molécula HLA-G, expressa principalmente na placenta, modulando a ação das células NK durante a gestação. O gene KIR2DL4 parece ser bastante variável, quando considerado os bancos de dados que armazenam suas sequências conhecidas, porém não está claro o nível de diversidade deste gene em populações reais e heterogêneas. Polimorfismos presentes no gene KIR2DL4 poderiam influenciar a interação entre KIR2DL4 e HLA-G, modificando a ação das células NK. Neste estudo exploramos a variabilidade genética de KIR2DL4 em 157 indivíduos oriundos do Estado de São Paulo/Brasil. Devido à alta similaridade de sequências entre os genes KIR, erros de genotipagem são esperados quando se utiliza sequenciamento de segunda geração. Por este motivo, desenvolvemos uma abordagem para classificar cada leitura com base em sequências KIR conhecidas, endereçando-as ao gene mais provável. Também utilizamos o painel SNPforID 34-plex para avaliar a ancestralidade dessas amostras. Considerando o segmento completo desse gene, indo da região 5’URR até a 3’UTR, com aproximadamente 13kb, o gene KIR2DL4 se mostrou pouco polimórfico, com 152 pontos de variações identificados (MAF 1%). Esses pontos de variação estão organizados em 32 haplótipos estendidos que codificam 13 proteínas diferentes. Foram encontrados 11 haplótipos na região promotora, sendo que 8 possuem MAF maior que 1%. Na região codif... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: KIR2DL4 is the most unusual Killer Cell Immunoglobulin-Like receptor (KIR) family member in terms of structure, expression, and signaling properties. The only known KIR2DL4 ligand is HLA-G, and polymorphisms might disrupt this interaction. KIR2DL4 variability is not well explored in admixed populations. Here we explored KIR2DL4 exon variability in 157 individuals from the State of São Paulo/Brazil. Because of sequence similarity with other KIR genes, it is expected genotyping errors when using secondgeneration sequencing. We developed an approach to score each read based on known KIR sequences, addressing them to the most likely locus. We evaluated the SNPforID 34-plex panel to assess ancestry. The methodology was applied to survey the variability of a very admixed population, such as Brazilian, counting with 157 samples of São Paulo State. Considering a segment of about 13-kb, KIR2DL4 gene was conserved with few different and frequent sequences. Overall, 152 variable sites were detected, arranged in 32 haplotypes codifying 13 protein. We found 11 promoter haplotypes, 8 with a frequency greater than 1%. In the coding region we detected 70 haplotypes, four of which correspond to 50% of the coding sequences (KIR2DL4 * 0080204, * 008105, * 001, * 005). In the 3'UTR region, 14 haplotypes were identified with MAF greater than 1%. The KIR2DL4 coding region was the most variable segment. We observed that KIR2DL4 variability is strongly influenced by the sample ancestry background. K... (Complete abstract click electronic access below) / Mestre
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Estudo da ampliação de escala do processo de pré-tratamento alcalino do bagaço de cana-de-açúcar para obtenção de etanol de segunda geração / Scale up study of sugarcane bagasse alkaline pretreatment process for second generation ethanol production

Nakanishi, Simone Coelho 05 October 2016 (has links)
No presente trabalho, dados de ampliacao de escala, de um processo de pre-tratamento alcalino em escala laboratorial (2L) para escala piloto (350L) foram avaliados. Os experimentos realizados previamente em escala laboratorial apontaram duas condições potenciais para a ampliacao de escala, a saber: Ensaio 5 (130°C, 30 min, 1,5% m/v NaOH, 0,15% m/m antraquinona) apresentando a maior conversao enzimatica da polpa obtida (64,5%) e Ensaio 7 (170°C, 1,5 % m/v NaOH, 30 min, 0,15% m/m antraquinona) com a maior solubilizacao de lignina (81,0 %). Os experimentos em escala piloto foram realizados nas condicoes apontadas, com e sem a adicao de antraquinona. A reprodutibilidade dos dados em escala piloto foi satisfatoria, considerando o sistema de aquecimento e agitacao mais eficientes do reator piloto em relacao ao reator usado no laboratorio. O uso da antraquinona diminuiu a solubilizacao de carboidratos durante o pretratamento (evitando 67% de solubilizacao quando comparado a reacao sem antraquinona, a 130°C), mas interferiu negativamente na etapa subsequente de hidrolise, principalmente na reacao a 170°C. Dentre as condicoes testadas, o ensaio 5Pil/AQ (130°C, 30 min, 1,5% NaOH e 0,15% m/m antraquinona) foi eleito como a melhor condicao de pre-tratamento, com maior rendimento em carboidratos apos a hidrolise enzimatica, sendo possivel obter (extrapolando os resultados) 290 kg de glicose e 98 kg de xilose a partir de uma tonelada de bagaco (base seca). Para a obtencao de etanol a partir desse hidrolisado, foram realizadas fermentacoes com tres diferentes leveduras - S. cerevisiae CAT-1, S. stipitis NRRL Y-7124 e S. passalidarum NRRL Y-27907. O melhor resultado foi apresentado para fermentacao em batelada alimentada aplicando reciclo de celulas utilizando a levedura S. passalidarum, produzindo 23,3 g/L de etanol (97 % do teorico) com produtividade de 0,90 g/L.h em 24 h de fermentacao no terceiro reciclo. O processo de pre-tratamento alcalino gera, alem da polpa rica em carboidratos, um hidrolisado rico em lignina. A lignina foi precipitada desse hidrolisado apos cada pre-tratamento realizado e caracterizada, apresentando poder calorifico entre 22,8 e 25,3 MJ/kg. / In this study, data scale up for an alkaline pretreatment process from lab to pilot scale was evaluated. Lab scale experiments indicated two potential conditions for the scale-up, namely: 130°C, 30 min, 1.5% w/v NaOH, 0.15% w/w anthraquinone , presenting the highest enzymatic conversion (64.5%); and 170°C, 30 min, 1.5% w/v NaOH, 0.15% w/w anthraquinone with the highest lignin solubilization (81.0 %). The experiments were performed on pilot scale under the aforementioned conditions, with and without anthraquinone. Data reproducibility on pilot scale was satisfactory considering the more efficient heating and stirring reactor system when compared to the reactor in lab scale. Anthraquinone decreases the solubilization of carbohydrates during pretreatment (avoiding 67% solubilization compared to the reaction without anthraquinone, at 130°C), but interferes negatively in the subsequent hydrolysis step, mostely at 170°C. Among the conditions tested, the test performed at 130°C, 30 min, 1.5% w/v NaOH and with 0.15% w/w anthraquinone was chosen as the best pretreatment condition, with the highest carbohydrate conversion after enzymatic hydrolysis, allowing 290 kg of glucose and 98 kg of xylose per a dry base ton of bagasse. In order to produce ethanol from this hydrolyzate, fermentations with three different yeasts were performed - S. cerevisiae CAT-1, S. stipites NRRL Y-7124, S. passalidarum NRRL Y-27907. Fed-batch fermentation with S. passalidarum cell recycling provided the best result, yielding 23.3 g/L ethanol, 97 % (theoretical yield) with 0.90 g/L.h productivity within 24 h of fermentation. The alkaline pretreatment process generates, besides the pulp rich in carbohydrates, a lignin-rich hydrolyzate. Lignin was precipitated from the hydrolyzate obtained after each pretreatment carried out and characterized, presenting heating values between 22.8 and 25.3 MJ/kg.

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