Utilização de derivados de calixarenos no isolamento de proteínas e biocatálise em solventes orgânicos

Tese de mestrado em Química Analítica Aplicada, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2008Neste trabalho foram utilizados ácidos carboxílicos derivados dep-tert-butilcalix[4,6,8]areno na extracção selectiva de duas proteínas: a mioglobina ea hemoglobina. Os três calixarenos apresentaram a capacidade de extrair as proteínas para a fase orgânica, com parâmetros de extracção superiores a 0,90.Estas proteínas demonstraram pseudoactividade de peroxidase na reacção deoxidação da seringaldazina na presença de peróxido de hidrogénio, quer em meio aquoso quer em meio orgânico usando o derivado ácido de p-tert-butilcalix[6]arenoem clorofórmio. A biocatálise destas duas proteínas foi investigada variando os seguintes parâmetros: pH, concentração da proteína e do substrato. A actividade específica máxima da mioglobina foi determinada em meios aquoso e orgânico obtendo-se os valores de 1,08 x 10-1 e 1,37 x 10-1 U. mg proteína-1 a pHinicial de 6,5, respectivamente. A hemoglobina apresentou em meio aquoso actividade específica máxima de 1,04 U. mg proteína-1 a pH 5,5 e em meio orgânico de 9,92 x 10-2 U. mg de proteína-1, a pH inicial de 7,5.Os parâmetros cinéticos em meio aquoso (Vmáx, Km, kcat e kcat/Km) foram determinados em função do pH, assim como os parâmetros cinéticos aparentes(V'máx, K'm, k'cat e k'cat/K'm) em meio orgânico. A estabilidade do complexo proteína-calixareno foi analisada para ambas as proteínas em função do pH inicial tendo-se obtido valores de t1/2 na gama de2 5 dias. Os complexos proteína-calixareno no meio orgânico foram recuperados para soluções aquosas frescas alcalinas, com valores de recuperação da pseudo actividade de peroxidase superiores a 100%.O derivado ácido de p-tert-butilcalix[6]areno foi utilizado na extracção da hemoglobina a partir de sangue humano obtendo-se um valor de 0,50 para o parâmetro de extracção. A proteína foi purificada a partir de sangue humano usando uma matriz cromatográfica de um polímero contendo unidades de p-tertbutilcalix[6]areno na forma ácida, com um rendimento final de pseudo actividade da hemoglobina de 34,42 % e um factor de purificação de 12. A análise electroforéticada preparação purificada da hemoglobina revelou uma banda de proteína com Mr de61 kDa em PAGE nativa que foi coincidente com a banda de pseudo actividade deperoxidase in situ.Derivatives of p-tert-butilcalix[4,6,8]arene carboxylic acids were used for selective extraction of two proteins myoglobin and hemoglobin. All three calixarenes were found to extract these two proteins to organic phase, exhibiting extraction parameters higher than 0,90.These proteins revealed pseudoactivity of peroxidase which catalysed the oxidation of seryngaldazine in the presence of hydrogen peroxide both in aqueous medium and in presence of tbutil[6]CH2COOH in chloroform. The effect of pH, protein and substrate concentrations was investigated in biocatalysis by using myoglobin and hemoglobin. The highest specific activities of myoglobin were 1,08 x 10-1 and1,37 x 10-1 U. mg protein-1 both in aqueous and organic media, respectively at pH 6,5whereas hemoglobin presented specific activities of 1,04 U. mg protein-1 at pH 5,5 in aqueous medium and 9,92 x 10-2 U. mg protein-1, at initial pH 7,5 in organic medium. Kinetic parameters (Vmáx, Km, kcat and kcat/Km) were determined in aqueous media at different pH and apparent kinetic parameters (V'máx, K'm, k'cat and k'cat/K'm) were also obtained in organic medium. Furthermore, the stability of the protein-calixarene complexes was investigated for different initial pH values and t1/2 values were obtained in the range of 2 5 days. Protein-calixarene complexes in organic medium were recovered in alkaline fresh aqueous solutions with recovery of pseudo activity of per oxidase over 100 %.Subsequently, p-tert-butilcalix[6]arene acid derivative was used for the extraction of hemoglobin from human blood with an extraction parameter of 0,5. Achromatographic matrix of a polymer containing units of acid derivative p-tertbutilcalix[6]arene was used for purification of hemoglobin from human blood with a final recovery of pseudo activity of peroxidase of about 34 % and a purification factor of 12. The purified preparation of hemoglobin was apparently homogeneous on native PAGE running with an approximate Mr of 61 kDa which was coincident with in situ detection of pseudo activity of peroxidase

Ensinar e aprender línguas estrangeiras na Universidade Aberta: exemplos de práticas comunicativas online

Ensinar e aprender uma língua estrangeira a distância implica vários desafios, nomeadamente ao nível da oralidade. Na Universidade Aberta, com base no modelo pedagógico virtual (Pereira et al, 2007) e no Quadro Europeu Comum de Referência para as Línguas Estrangeiras (Alves, 2001), propomos percursos curriculares que contemplam práticas comunicativas online, escritas e orais, no âmbito da atual oferta pedagógica. Assim, neste texto, partilhamos alguns exemplos de atividades formativas nas línguas alemã, francesa e inglesa, com ênfase na componente oral, a partir de recursos digitais. Estes recursos digitais incluem materiais multimédia, quer da autoria dos docentes, quer dos discentes, e ainda outros materiais disponíveis na web 2.0. As nossas práticas, de docência e de investigação, na área das línguas estrangeiras e do eLearning, permitem-nos concluir que os recursos digitais utilizados se adequam ao ensino e aprendizagem de línguas estrangeiras online, sobretudo junto de um público adulto ativo profissionalmente, como é o da Universidade Aberta.Teaching and learning a foreign language at a distance implies many challenges, namely regarding oral skills. At Universidade Aberta (the Portuguese Open University), and taking into account its virtual pedagogical model (Pereira, 2007) and the Common European Framework of Reference for Languages (Alves, 2001), we suggest curricular paths which include online communicative practices, both oral and written, within the present pedagogical offer. Thus, in this text, we share some examples of training activities in German, French and English, focusing on oral practice, and based on digital resources. These digital resources comprise multimedia materials, either produced by the teachers or the students, as well as other materials available on the web 2.0. Our teaching and research practice within the field of foreign languages and in eLearning, in particular, leads us to conclude that the digital resources used are suitable for the online teaching and learning of foreign languages, especially for professionally engaged adults, as it is the case with Universidade Aberta’s students.info:eu-repo/semantics/publishedVersio

Enriching MATLAB with aspect-oriented features for developing embedded systems

This article presents an approach to enrich the MATLAB language with aspect-oriented modularity features, enabling developers to experiment different implementation characteristics and to acquire runtime data and traces without polluting their base MATLAB code. We propose a language through which programmers configure the low-level data representation of variables and expressions. Examples include specifically-tailored fixed-point data representations leading to more efficient support for the underlying hardware, e.g., digital signal processors and application-specific architectures, without built-in floating point units. This approach assists developers in adding handlers and monitoring features in a non-invasive way as well as configuring MATLAB functions with optimized implementations. Different aspect modules can be used to retarget common MATLAB code bases for different purposes and implementations. We validate the proposed approach with a set of representative examples where we attain a simple way to explore a number of properties. Experiment results and collected aspect-oriented software metrics lend support to the claims on its usefulness.This work was partially supported by FCT (Portuguese Science Foundation) under the project AMADEUS (POCTI, PTDC/EIA/70271/2006)

The effect of school-based physical activity interventions on body mass index: a meta-analysis of randomized trials

This study reviewed the effectiveness of school-based physical activity interventions aimed at reducing overweight, obesity and hypertension in children. We searched 14 databases and analyzed studies published between April 2009 and September 2012. Only randomized controlled trials performed at the school level that included elements of physical activity but did not include nutritional co-interventions were analyzed. Studies were assessed by two recommended tools (EPHPP and GRADE), and the standardized mean differences with 95% confidence intervals were collected for a random-effect meta-analysis. A total of 12 papers were included in the meta-analysis, and these were divided according to three outcomes: body mass index (11 trials, n  =  4,273, −0.02, 95% CI: −0.13 to 0.17, p  =  0.8); body weight (5 trials, n  =  1,330, −0.07, 95% CI: −0.18 to 0.04, p  =  0.2); and blood pressure (6 trials, n  =  1,549), including systolic (0.11, 95% CI: −0.10 to 0.31, p  =  0.3) and diastolic pressure (−0.00, 95% CI: −0.10 to 0.10, p  =  0.9). This meta-analysis of data from 11 randomized, school-based physical activity interventions suggests that, regardless of the potential benefits of physical activity in the school environment, the interventions did not have a statistically significant effect. However, it is difficult to generalize from these results because the duration, intensity and type of physical activity used in the interventions varied greatly.Cotas do Programa de Pos-Graduacao do Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa de Sao Paulo (FAPESP)Universidade de São Paulo Hospital das Clinicas Faculdade de MedicinaFederal University of São PauloFederal University of São Paulo Pediatrics Department, NutrologyUNIFESP, Pediatrics Department, Nutrology09/12438-5SciEL

Electronic arts : equity valuation

The following master thesis was elaborated by David Cardoso under the orientation of professor Dr. José Carlos Tudela Martins. The master thesis has as its main objective the valuation of Electronic Arts, a US based gaming/entertainment company. The Company was founded back in 1982 and since then has been operating in the mentioned sector namely by making game software for platforms such as personal computers, consoles and more recently smartphones. The Company has been enjoying success through its game franchises mainly in the sports category. The valuation process was made through two methods: Discounted Cash flows and Multiple relative valuation. In the DCF method, the Company’s future cash flows are estimated and discounted to present day. All those cash flows are then summed and yield the Enterprise value. The next procedure would be to add the cash in the balance sheet and subtract the Company’s debt to yield the Equity value. If the Equity value is divided by the number of shares outstanding which will result in the estimated value per share. In the Multiples relative valuation process, the financials of similar companies are used to make a comparison between what those companies are valued and what the Company should be valued. Finally, after doing both processes a final recommendation of buying and/or holding the Company.A seguinte tese de mestrado foi elaborada por David Cardoso sob a orientação do professor Dr. José Carlos Tudela Martins. O objetivo da tese é a avaliação do valor da empresa – Electronic Arts, uma empresa dos EUA que opera na indústria de jogos. A Empresa foi fundada em 1982 e desde aí tem operado no sector mencionado, fazendo software de jogos para computadores pessoais, consolas e mais recentemente smartphones. A EA tem tido bastante sucesso no seu negócio, nomeadamente na produção de jogos desportivos. O processo de avaliação foi feito através de dois métodos: Discounted Cash Flows e Multiple relative valuation. No primeiro método, os potenciais ganhos futuros da Empresa são estimados e subsequentemente descontados para o seu valor no presente com o objetivo de os somar e obter o valor total da Empresa. De seguida adiciona-se o dinheiro em caixa e subtrai-se a divida da Empresa, obtendo assim o valor dos Capitais Próprios da Empresa. Se dividirmos este último valor pelo número total de ações disponíveis chegaremos ao valor por ação. No Segundo método descrito, usam-se os valores de empresas parecidas à Electronic Arts com o objetivo de depreender qual será o valor da Empresa tendo em conta o valor de mercado das empresas que são parecidas. Finalmente, após fazer ambos os processos, a recomendação final é a de comprar e/ou manter ações da Empresa

Online buying behavior in technological and office products

The evolution and growth of E-commerce nowadays is irrefutable. The revolution and introduction of new technologies have profound implications in business management, offering tools for the globalization of the market. This evolution and change in the market also leads to different realities towards not just the business itself but also the consumer. It is important to understand what are the main features of information search and purchase behavior online and understand online consumer behavior (what are the characteristics, what motivates somebody to buy online, what are his fears, etc). This study aims, from existing knowledge about information search and purchase behavior online, to deepen the knowledge of Portuguese behavior to give information to companies to better develop their business. In this case, this study will be made for Technological and Office products.A evolução e o crescimento do E-Commerce hoje em dia é irrefutável. A revolução e a introdução de novas tecnologias têm implicações profundas na gestão empresarial, oferecendo ferramentas and a globalização do mercado. Este evolução e mudança no mercado leva a uma diferente realidade não só no negócio em si mas também no consumidor. É importante perceber quais são as principais caracteristícas na procura de informação online e na compra e perceber o comportamento do consumidor online (as suas características, as motivações, os medos, etc). Este estudo procura partir do conhecimento existente sobre o comportamento da procura de informação e compra online, aprofundar o conhecimento do comportamento dos Portugueses de forma a dar informação às compresas de como desenvolver melhor o seu negócio. Neste caso, o estudo será feito sobre produtos de Tecnologia e Escritório

Intra and Inter-Spore Variability in Rhizophagus irregularis AOX Gene

Funding: This work was supported by the European Commission through the project AGRO-AMF-AOX within the program Industry-Academia Partnerships and Pathways (IAPP, FP7). Still in the frame of the AGRO-AMF-AOX project, JS further acknowledges his recruitment, and CC, HC, AN, CS and BAS appreciate the further support given in the form of a secondment. Inoq GmbH provided support in the form of salary for CS, but did not have any additional role in the study design, data collection and analyses, decision to publish, or preparation of the manuscript. The specific role of CS is articulated in the ‘author contributions’ section. Part of this work was also supported by grant AGL2012-39923 from the Spanish National R&D Plant of the Ministry of Science and Innovation (MICINN). TN was supported by a Marie Curie fellowship (FP7-PEOPLE-2012-CIG Project Reference 321725) and by the Portuguese Foundation for Science and Technology – FCT (SFRH/BCC/52187/2013). The authors further thank the program POPH—Operational Program for Human Potential—and Fundo Europeu de Desenvolvimento Regional (FEDER) funds through the Operational Program for Competitiveness Factors—COMPETE, and national funds through FCT under the strategic project PEst-C/AGR/UI0115/2011 and PEst-OE/AGR/UI0115/2014.Peer reviewe