676 research outputs found

    The General Contract of Tobacco and the Azorean Economy (17th and 18th Centuries)

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    UIDB/04666/2020 UIDP/04666/2020From the second half of the 17th century, the Tobacco trade became one of the main revenues for the European colonial empires. In Portugal there was a general contract, based on a system of contracts and exclusive businesses, with associated financial and tax benefits. How were the regulatory and surveillance mechanisms of this monopoly transposed to insular spaces? What kind of behavior did contractors have in island society? What is the role of the tobacco trade in the Azorean economy? These are some of the questions we will try to answer in this text. A partir da segunda metade do século XVII, o comércio do tabaco passou a ser uma das principais receitas dos impérios coloniais europeus. Em Portugal existia um contrato geral, baseado em regime de contratos e negócios exclusivos, com benefícios financeiros e fiscais associados. Como foram transpostos para os espaços insulares os mecanismos reguladores e de vigilância deste monopólio? Que tipo de comportamentos tinham os contratadores na sociedade insular? Qual o papel do comércio do Tabaco na economia açoriana? Estas são algumas das perguntas que tentaremos responder neste texto.publishersversionpublishe

    Trabalho colaborativo e representações sociais: Contributos para a promoção do sucesso escolar, em matemática

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    Numa sociedade tecnológica e global, como a actual, são exigidas, aos cidadãos, capacidades e competências que lhes permitam ultrapassar os desafios. A matemática assume-se como uma forma de conhecimento, culturalmente situado, importante na mediação e resolução desses desafios. Enquanto disciplina associada a elevadas taxas de insucesso académico e a representações sociais negativas, é, muitas vezes, responsável por abandonos escolares precoces. O trabalho colaborativo, em díade ou pequenos grupos, actua como ferramenta mediadora no acesso ao sucesso académico e como facilitador no desenvolvimento de capacidades e competências (matemáticas), promovendo a literacia matemática. Este trabalho insere-se no projecto Interacção e Conhecimento. Assume um paradigma interpretativo e um design de investigação-acção. Os participantes são os alunos duma turma de 8.º ano de escolaridade, o professor/investigador e outros dois observadores. Os instrumentos de recolha de dados são um instrumento de avaliação de capacidades e competências (matemáticas), tarefas de inspiração projectiva, questionários, observação, recolha documental e protocolos dos alunos. Os dados foram tratados através de uma análise de conteúdo narrativa, sucessiva e aprofundada, de onde emergiram categorias indutivas. Analisamos as trajectórias de participação de uma aluna (Carolina, nome fictício), enquanto exemplo paradigmático. Discutimos estas trajectórias de participação em matemática, nomeadamente as três tarefas de inspiração projectiva e algumas tarefas matemáticas, realizadas em aula e em díade. Esta investigação ilumina as potencialidades que o trabalho colaborativo tem na apropriação de conhecimentos (matemáticos), na mobilização e/ou desenvolvimento de capacidades e competências (matemáticas), na mudança das representações sociais relativas à matemática e nos processos de socialização dos alunos.In a technological and global society citizens are demanded to use diverse abilities and competencies, allowing them to overcome societal challenges. Mathematics is a very important cultural tool to mediate and solve these challenges. This subject is associated with high academic failure, to the development of negative social representations, and is often responsible for some of the early school dropouts. Collaborative work, particularly peer interactions and small groups work, can be used as a mediating tool promoting students’ access to the academic achievement. It also facilitates the development of (mathematical) abilities and competencies contributing to the promotion of a mathematical literacy. This work is part of the Interaction and Knowledge project. It assumed an interpretative approach and an action-research design. The participants were the 8th grade students, the teacher/researcher and two other observers. Data was collected through an instrument to evaluate students’ (mathematical) abilities and competencies, tasks inspired in projective techniques, questionnaires, observation, documents and students' protocols. Data was treated and analysed through a narrative content analysis performed in a successive and in-depth way, from which inductive categories emerged. We analyse one student’s trajectory (Carolina, pseudonym), a paradigmatic example. We discuss this student’s life trajectories of participation, particularly in mathematics, namely the three tasks inspired in projective techniques and some mathematical tasks solved in dyads. This research illuminates the potential of collaborative work in the appropriation of (mathematical) knowledge, in the mobilization and/or development of (mathematical) abilities and competencies, in the change of social representations and in students’ socialization process

    A multibody approach to the contact dynamics: a knee joint application

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    In this thesis, a general approach for dynamic analysis of multibody systems with contact is presented, being a special attention given to the articular contact at the human knee joint. Two methodologies, in two- and three-dimensions, for knee contact modeling are proposed under the framework of multibody systems using generalized Cartesian coordinates. The development of the planar multibody knee model encompasses four steps: (i) geometrical representation of contacting profiles by means of curve fitting techniques based on spline interpolation functions; (ii) location of contact points and evaluation of the contact indentation; (iii) calculation of the contact forces by using an appropriate constitutive law; (iv) description of the ligament behavior by a quadratic stress-strain relation. The motion of the tibia relative to the femur is modeled combining the action of the knee ligaments with the potential contacts between the bones. The contact forces, together with the forces produced by the ligaments, are introduced into the Newton-Euler equations of motion as external generalized forces. Within the three-dimensional methodology, the contact surfaces are described by means of point-clouds extracted from parametric representations. The spatial formulation presents a pre-processing unit. This preprocessor allows for a significantly reduction of the amount of memory required for data storage and an improvement of the computational efficiency of the contact detection process. Computational simulations were performed with the aim of validating both proposed approaches, two-dimensional and three-dimensional. The behavior of the planar knee model resultant of the application of different contact force laws was studied. Moreover, the influence of the geometric and material properties on the dynamic response of the knee joint model was investigated. In a broad sense, the proposed methodologies demonstrated to be suitable for the analysis of the dynamic behavior of multibody models with contact, especially those biological systems such as the knee joint that involve complex geometries, a large range of motion and high dynamic loads.Nesta tese é proposta uma abordagem genérica para a análise dinâmica de sistemas de corpos múltiplos com contacto, dando um especial enfoque ao contacto articular no joelho humano. No âmbito da dinâmica de sistemas de corpos múltiplos são apresentadas duas metodologias, bidimensional e tridimensional, para a modelação do contacto no joelho usando coordenadas cartesianas generalizadas. O desenvolvimento do modelo bidimensional do joelho engloba quatro etapas: (i) representação geométrica dos perfis de contacto por meio de técnicas de ajuste de curva com base em funções de interpolação por splines, (ii) localização dos pontos de contacto e avaliação da indentação de contacto, (iii) cálculo das forças de contacto usando uma lei constitutiva apropriada, (iv) descrição do comportamento dos ligamentos através de uma relação quadrática de tensão-deformação. O movimento da tíbia em relação ao fémur é modelado como uma acção combinada entre os ligamentos do joelho e os potenciais contactos entre os ossos. As forças de contacto, juntamente com as forças produzidas pelos ligamentos, são introduzidas nas equações de movimento de Newton-Euler como forças externas generalizadas. Na metodologia tridimensional, as superfícies de contacto são descritas por meio de nuvens de pontos extraídas de representações paramétricas. No âmbito da formulação tridimensional é apresentada uma unidade de pré-processamento. Este pré-processador permite uma redução significativa da quantidade de memória necessária para o armazenamento de dados e, desta forma, melhora a eficiência computacional do algoritmo de deteção de contacto. Com o objetivo de validar as metodologias propostas, realizaram-se várias simulações computacionais. Os comportamentos do modelo bidimensional do joelho resultantes da aplicação de diferentes leis de força de contacto foram estudados. A influência das propriedades geométricas e de material na resposta dinâmica do modelo bidimensional do joelho foi investigada. De uma forma geral, as metodologias propostas demonstraram ser adequadas para a análise do comportamento dinâmico de modelos de corpos múltiplos com contacto, especialmente sistema biológicos, como o joelho humano, que envolvem geometrias complexas, uma grande amplitude de movimentos e elevadas cargas dinâmicas

    Equity research - Galp Energia SGPS SA : valuation of the power business unit

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    Mestrado em FinançasEste projeto consiste num relatório de avaliação da empresa GALP Energia S.G.P.S., S.A., com especial foco na unidade de negócio de eletricidade e a contribuição dos seus projetos solares mais recentes para o preço-alvo de 2020YE. O relatório segue o formato recomendado pelo CFA Institute, uma vez que, grande parte do mesmo, foi submetido para o CFA Institute Research Challenge de 2020. A GALP é a principal Empresa Integrada de Petróleo em Portugal. Opera em toda a cadeia de valor do combustível fóssil, desde a extração do mesmo, o seu transporte e refinação, e por fim a comercialização dos diferentes subprodutos. Foi aplicada a abordagem de Soma das Partes para avaliar a GALP, aplicando o FCFF DCF a cada unidade de negócio, de forma a refletir todas as idiossincrasias de cada unidade. O resultado gerou um preço-alvo de 12,1€/sh. Foram também utilizados outros métodos para complementar a avaliação, como o FCFF DCF para a empresa como um todo, o FCFE DCF, o APV e o DDM. Foi ainda realizada uma análise complementar à contribuição dos projetos mais recentes da GALP em energia solar, para o preço-alvo inicial de 12,1€/sh, uma vez que o nosso relatório inicial não considerou esses projetos porque apenas foram anunciados após a conclusão do relatório inicial. Ao adicionar os investimentos mais recentes da GALP em projetos de energia solar, a minha recomendação de investimento fornece informações mais precisas e atualizadas aos investidores e às suas decisões de investimento. Este capítulo reforça a nossa recomendação de compra.This project is an Equity Research of GALP Energia S.G.P.S., S.A., with a special focus on the value added by the power business unit's most recent solar projects to the initial 2020YE price target. The report follows the CFA Institute format, as a significant portion of it was submitted for the 2020 CFA Institute Research Challenge. Only public information released until January, 2nd 2020 was considered. GALP is the leading Portuguese Integrated Oil Company. It operates throughout the whole fossil fuel value chain, from extracting fossil fuel, to transporting and refining it, and then commercializing the different by-products. It was applied a Sum-of-the-Parts approach to value GALP, where a FCFF DCF was applied to each business unit, reflecting all the idiosyncrasies of each unit. The result yielded a final price target of 12.1€/sh. Other methods were also used to support the valuation, such as a FCFF DCF for the company as a whole, FCFE DCF, the APV and the DDM. A complementary analysis to the contribution of GALP's most recent projects in solar energy to the initial price target of 12.1€/sh was carried out, since our initial report didn't incorporate these projects, as they were announced after the initial report was concluded. By adding GALP's most recent investments in solar energy projects, I believe our investment recommendation provides more accurate and updated information to investors and to their investment decision. It is also of importance to highlight that this chapter further supports our buy recommendation.info:eu-repo/semantics/publishedVersio

    Grandes branquiópodes dulçaquícolas em Portugal: actualização da sua distribuição

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    This study is based largely on 20 years of field and laboratory work, with surveys conducted by the authors and some other researchers. During this period several studies dealing with freshwater large branchiopods (FLB) were carried out, resulting in scientific publications and project reports. The distribution of FLB in Portugal was presented in 2 international scientific meetings, but apart from a first paper by Vianna-Fernandes in 1951 and an update done by ourselves in 1999 concerning the southwest Portugal, no other information has been published. Therefore, this work intends to bring up to date the known distribution of this faunal group in freshwater temporary systems. This is pertinent because of the recent revision of the taxon Triops cancriformis on the basis of genetic analyses. The Portuguese populations were assigned either to the Portuguese endemism T. vicentinus, or to T. baeticus, the more widely spread Iberian species, both belonging to the T. mauritanicus complex. Furthermore, a new species, Tanymastigites lusitanica was found and described in Portugal. More recently, a male free (or, at least, a strongly female-biased) metapopulation of T cancriformis was discovered in a rice field in the central region of Portugal. Here we present an updated status of FLB species of Portuguese temporary lentic systems and their distribution, plotted on a UTM (10 x 10 km) grid. A total of 505 sites (temporary ponds or assemblages of closely located, not individual temporary pools) have been surveyed (455 by us). In 241 of these (47.7%) at least one species of FLB was found on at least one occasion. Of the 505 sites, only 87 are located north of the Tagus River and of these, at least one species was found in only 17 (19.5%). South of the Tagus River (Alentejo and Algarve), 53.6% of the sites were inhabited by at least one species. This list comprises 7 anostracans, 2 spinicaudatans and 4 notostracans, including 3 species endemic to the Iberian Peninsula and another 3 to Portugal.O presente trabalho é, maioritariamente, o resultado de 20 anos de trabalho de campo e de laboratório, com campanhas realizadas pelos autores e por outros investigadores. Durante este período foram realizados vários estudos de que resultaram diversas publicações e relatórios de projectos. O conhecimento da distribuição dos grandes branquiópodes dulçaquícolas (GBD) em Portugal baseia-se num primeiro artigo de 1951 de Vianna-Fernandes e de uma actualização do conhecimento publicada por nós em 1999 e relativa ao sudoeste de Portugal. A sua actualização foi posteriormente apresentada em dois encontros científicos internacionais, mas nunca foi publicada. Assim, este trabalho pretende actualizar o conhecimento sobre a distribuição, em Portugal, deste grupo faunístico de sistemas lênticos temporários. Esta intenção é pertinente, visto que, na última década, o taxon Triops cancriformis foi revisto com base em análises genéticas. As populações portuguesasforam atribuídas quer ao endemismo português T. vicentinus, quer a T. baeticus, a espécie com distribuição mais alargada na península ibérica, ambas anteriormente incluídas no complexo T. mauritanicus. Além destas, uma nova espécie, Tanymastigites lusitanica foi descoberta e descrita em Portugal. Mais recentemente, foi encontrada num campo de cultivo de arroz na região central de Portugal, uma metapopulação de T. cancriformis aparentemente composta unicamente por fêmeas. Apresenta-se neste trabalho o estado actual do conhecimento sobre a distribuição dos GBD de sistemas lênticos temporários portugueses, em mapas de quadrícula UTM (10 × 10 km). Foram prospectados um total de 505 sítios (charcos temporários ou conjuntos de charcos com localização próxima, não individualizável), 455 pelos autores. Em 241 deles (47.7%) foi observada a presença de pelo menos uma espécie de GBD numa ocasião. Dos 505 sítios, apenas 87 estão localizados a Norte do rio Tejo, e nestes apenas em 17 (19.5%) foi detectada a presença de pelo menos 1 espécie de GBD. A sul do rio Tejo (Alentejo e Algarve), em 53.6% dos sítios foi encontrada pelo menos uma espécie de GBD. Esta lista inclui 13 espécies (7 Anostraca, 2 Spinicaudata e 4 Notostraca), entre as quais 3 endemismos ibéricos e outros 3 endemismos portugueses.FCT - Foundation for Science and Technology [UID/Multi/04326/2013, UID/MAR/04292/2013]LIFE + Nature Project "Conservacao de charcos temporarios na costa Sudoeste de Portugal""Estudo da Ecologia das Lagoas Temporarias do Sudoeste de Portugal"-Protocolo de colaboracao CCMAR-PNSACV, ICN funding"Identificacao dos Elementos de Conservacao (Fauna de Crustaceos Filopodes e Anfibios) nos Char cos temporarios do Parque Natural do Vale do Guadiana e Areas limitrofes"-Protocolo de colaboracao CCMAR-ICN, ICN funding"Estudo dos Grandes Branquiopodes das Lagoas Temporarias na area de influencia dos Parques Naturais do Tejo Internacional e da Serra de Aires e Candeeiros"PNTIPNSAC chiefdomsConsorcio BIO3 / Matos, Fonseca & Associados, Estudos e Projector, Lda-"Plano de Conservacao para os Charcos Temporarios Mediterranicos na regido de implementacao do EFMA", EDIA fundinginfo:eu-repo/semantics/publishedVersio

    The influence of leisure activities on the health and welfare of older people living in nursing home

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    Background: Leisure activities, often left in the background throughout life, play an important role for older persons. They are activities that they like to accomplish, according to individual preferences that make it easier to maintain an active life, on a physical, mental and social level, improving their health. Objectives: I) Identify the leisure habits of older people living in nursing homes; II) Describe the nursing homes’offer of leisure activities; III) Identify relationships between leisure activities and the seniors’health condition. Methods: A cross-sectional descriptive correlational study, in 12 nursing homes in the north of Portugal with a sample of 1,131 seniors. We performed a descriptive and inferential statistical data analysis using SPSS/PC for Windows, version 22. Results: Participants were mostly female, widows, with an average age of 84 years. The most common leisure activity is watching TV. Impaired sight and illiteracy are the most frequent causes of elderly people’s non-adherence to leisure activities. Leisure activities: card/board games, crafts and reading are associated with better cognitive performance; sightseeing and reading are associated with greater independence in self-care; watching television is associated with greater compromise of bodily processes and greater dependence on self-care; performing manual work is associated with less depression; walking is associated with a lower compromise of bodily processes and lower risk of falling. Conclusions: Leisure habits are important in maintaining the health of older people living in nursing homes.info:eu-repo/semantics/publishedVersio

    Repercussions of tobacco, alcohol and drugs on adolescents' health. Modalities of interaction and reciprocal influence

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    Attachment has often been identified as key-variable for the understanding of developmental vulnerability to health risk behaviours among children and adolescents. On the other hand the association of a past history of somatic illness to later involvement in health risk behaviours is an increasingly relevant public health issue. This study was aimed at determining the influence of both somatic antecedents and attachment style on substance use behaviours among 15-18 year-olds. It further tested the empirical validity of a mediator model to explain the role of adolescents' attachment behaviour on the interaction between somatic antecedents and substance use. To achieve such goals an epidemiological survey was conducted on a panel sample of children and adolescents randomly selected from the population of the same age consulting at Coimbra Health Sub-region primary care services. Even if the probabilistic validity of the mediator model was not proven, the parental perception of insecure (anxious/avoidant) attachment, particularly among youngsters with significant past history of somatic disorders, proved to be a key risk factor for adolescent involvement in substance use behaviours

    Solvent-cast films of an elastin-like polymer fused to an antimicrobial peptide, ABP-CM4, exhibits high antibacterial activity against pseudomonas aeruginosa

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    The nosocomial infections grew significantly in the last years and became a worldwide problem. Antimicrobial peptides (AMPs) arise as a good treatment to these infections, since traditional antibiotics have become useless against resistant hospital strains. AMPs exhibit a broad range of antimicrobial activity but antitumoral and antiviral activities have also been found. AMPs are usually small, cationic molecules that occur as part of the innate defense mechanism in many organisms, even in microbes and virus. The combination of AMPs with recombinantly produced polymers, such as the Elastin-like Polymers (ELPs), inspired in the mammalian elastin, could improve medical equipment, such as catheters, to overcome infections and biofilms formation. In this work we describe the cloning and recombinant production in Escherichia coli BL21(DE3) of ABP-CM4, a cationic AMP from Bombyx mori, fused to an ELP, consisting of 200 repeats of the pentamer VPAVG (A200). This ELP exhibits thermoresponsive properties, exploitable as a purification method. The morphological characteristics as well as its antibacterial activity of this hybrid polymer were studied as essential for the applicability in medical devices. The ABP-CM4 gene was chemically synthesized, with the inclusion of a formic acid cleavage site, and fused in frame with the N-terminus of the gene coding A200. Production of the recombinant polymer in E. coli BL21(DE3) was achieved and purification was based on the use of the inverse transition cycling method. Formic acid treatment allowed tag removal and obtention of the soluble protein. The hybrid polymer, CM4::A200, and the cleaved ABP-CM4 were tested for its antimicrobial activity in liquid form. Solvent-cast films of CM4::A200, using formic acid as solvent, were tested for the antibacterial activity against Pseudomonas aeruginosa comparing with A200 polymers containing different contents of positively charged aminoacids. The hybrid polymer presented similar morphological and physicochemical features to A200. The cleaved recombinant ABP-CM4 and CM4::A200 showed low levels of inhibition against P. aeruginosa in the liquid form but, in the solvent-cast film form, the inhibition of growth of was almost 100%. This result reveals very good perspectives for the use of these polymers in the medical equipment.Fundação para a Ciência e a Tecnologia (FCT
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