A perceção dos alunos sobre a Educação Física à entrada do ensino secundário: um estudo comparativo entre o ensino regular e profissional

Relatório de estágio de mestrado em Ensino de Educação Física nos Ensinos Básico e Secundário

Pesquisa experimental para avaliação da eficiência da fibra de aço na resistência à punção de lajes lisas reforçadas simetricamente

O presente artigo é dedicado à avaliação experimental da eficiência do reforço com fibra de aço em termos da resistência à punção de lajes lisa carregadas simetricamente. Para este fim, oito lajes de 2550 x 2550 x 150 mm3 foram ensaiadas até a ruína, onde se investigou a influência do consumo de fibras (0, 60, 75 e 90 kg/m3) e da resistência do concreto (50 e 70 MPa). Duas lajes de referência, sem fibras, uma para cada classe de resistência do concreto, e uma laje para cada consumo de fibra e para cada classe de resistência do concreto compuseram o programa experimental. Todas as lajes foram armadas à flexão com barras de aço (armadura convencional) de forma a garantir a ruína por punção das lajes de referência. O único reforço transversal foi garantido pelas fibras de aço hooked ends com comprimento e diâmetro de 37 e 0,55 mm, respectivamente, e resistência à tração de aproximadamente 1100 MPa. Os resultados revelaram que as fibras de aço são muito eficientes em converter uma ruína frágil por cisalhamento em uma ruína dúctil por flexão, aprimorando ambos, carga de ruptura e deslocamento. Neste artigo o programa experimental é abordado em detalhe e os principais resultados são apresentados e discutidos.

Assessment of the effectiveness of steel fibre reinforcement for the punching resistance of flat slabs by experimental research and design approach

The present paper deals with the experimental assessment of the effectiveness of steel fibre reinforcement in terms of punching resistance of centrically loaded flat slabs, and to the development of an analytical model capable of predicting the punching behaviour of this type of structures. For this purpose, eight slabs of 2550 x 2550 x 150 mm3 dimensions were tested up to failure, by investigating the influence of the content of steel fibres (0, 60, 75 and 90 kg/m3) and concrete strength class (50 and 70 MPa). Two reference slabs without fibre reinforcement, one for each concrete strength class, and one slab for each fibre content and each strength class compose the experimental program. All slabs were flexurally reinforced with a grid of ribbed steel bars in a percentage to assure punching failure mode for the reference slabs. Hooked ends steel fibres provided the unique shear reinforcement. The results have revealed that steel fibres are very effective in converting brittle punching failure into ductile flexural failure, by increasing both the ultimate load and deflection, as long as adequate fibre reinforcement is assured. An analytical model was developed based on the most recent concepts proposed by the fib Mode Code 2010 for predicting the punching resistance of flat slabs and for the characterization of the behaviour of fibre reinforced concrete. The most refined version of this model was capable of predicting the punching resistance of the tested slabs with excellent accuracy and coefficient of variation of about 5%.

O incumprimento da obrigação de pagamento da renda na locação financeira

Dissertação de mestrado em Direito dos Contratos e das Empresas

Da carreira às trajetórias de inserção profissional: o caso dos licenciados em educação de infância e em ensino básico (1.º ciclo), pela Universidade do Minho, entre 2001 e 2010

Tese de doutoramento em Estudos da Criança (área de especialização em Formação de Professores).

Risk of multiple myeloma is associated with polymorphisms within telomerase genes and telomere length

Compelling biological and epidemiological evidences point to a key role of genetic variants of the TERT and TERC genes in cancer development. We analyzed the genetic variability of these two gene regions using samples of 2,267 multiple myeloma (MM) cases and 2,796 healthy controls. We found that a TERT variant, rs2242652, is associated with reduced MM susceptibility (OR?=?0.81; 95% CI: 0.72-0.92; p?=?0.001). In addition we measured the leukocyte telomere length (LTL) in a subgroup of 140 cases who were chemotherapy-free at the time of blood donation and 468 controls, and found that MM patients had longer telomeres compared to controls (OR?=?1.19; 95% CI: 0.63-2.24; ptrend ?=?0.01 comparing the quartile with the longest LTL versus the shortest LTL). Our data suggest the hypothesis of decreased disease risk by genetic variants that reduce the efficiency of the telomerase complex. This reduced efficiency leads to shorter telomere ends, which in turn may also be a marker of decreased MM risk.

Estudo, projeto e desenvolvimento de uma máquina para montar e vincar sacos de papel

Dissertação de mestrado integrado em Engenharia Mecânica

Desenvolvimento de um filtro ativo paralelo monofásico compacto e didático utilizando MOSFETs

Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e Computadores

Seguidor do ponto de máxima potência multi-conversor para sistemas solares fotovoltaicos

Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e de Computadores

The Portuguese programme ‘one laptop per child’ and its impact on families: a study on parents’ and children’s perspectives

This paper intends to present and reflect upon some of the findings emerging from a research project entitled “Navigating with ‘Magalhães’: Study on the Impact of Digital Media on Schoolchildren” that was conducted at the Communication and Society Research Centre at the University of Minho, Braga, Portugal. The project focused on the politics of the governmental programme “One Laptop per Child” part of the Portuguese Technological Plan for Education, and the uses of the “Magalhães” computer, and other media, by children aged 8-10 years. This paper analyses the impact of this particular public policy on digital literacy of young children based mostly on the perspectives of parents and their modes of mediation. It also debates parents’ and children’s perspectives on parental rules on computer and Internet usage. It ends by concluding that the impact of this programme occurred mainly at the level of access rather than the social and educational uses and practices. It also highlights the importance of family in the way children access and use ICT.

The role of the mammalian DNA end-processing enzyme polynucleotide kinase 3'-phosphatase in spinocerebellar ataxia Type 3 pathogenesis

DNA strand-breaks (SBs) with non-ligatable ends are generated by ionizing radiation, oxidative stress, various chemotherapeutic agents, and also as base excision repair (BER) intermediates. Several neurological diseases have already been identified as being due to a deficiency in DNA end-processing activities. Two common dirty ends, 3'-P and 5'-OH, are processed by mammalian polynucleotide kinase 3'-phosphatase (PNKP), a bifunctional enzyme with 3'-phosphatase and 5'-kinase activities. We have made the unexpected observation that PNKP stably associates with Ataxin-3 (ATXN3), a polyglutamine repeat-containing protein mutated in spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph Disease (MJD). This disease is one of the most common dominantly inherited ataxias worldwide; the defect in SCA3 is due to CAG repeat expansion (from the normal 14-41 to 55-82 repeats) in the ATXN3 coding region. However, how the expanded form gains its toxic function is still not clearly understood. Here we report that purified wild-type (WT) ATXN3 stimulates, and by contrast the mutant form specifically inhibits, PNKP's 3' phosphatase activity in vitro. ATXN3-deficient cells also show decreased PNKP activity. Furthermore, transgenic mice conditionally expressing the pathological form of human ATXN3 also showed decreased 3'-phosphatase activity of PNKP, mostly in the deep cerebellar nuclei, one of the most affected regions in MJD patients' brain. Finally, long amplicon quantitative PCR analysis of human MJD patients' brain samples showed a significant accumulation of DNA strand breaks. Our results thus indicate that the accumulation of DNA strand breaks due to functional deficiency of PNKP is etiologically linked to the pathogenesis of SCA3/MJD.

A importância do profissional de relações públicas no e-commerce em Portugal

Relatório de estágio de mestrado em Ciências da Comunicação (área de especialização em Publicidade e Relações Públicas)

A proteção cumulativa do design pelo Direito de Autor e pelo Direito da Propriedade Industrial: o caso especial do contrato de trabalho

Dissertação de mestrado em Direito dos Contratos e das Empresas

Kinematic constraint equations

This chapter presents a general methodology for the formulation of the kinematic constraint equations at position, velocity and acceleration levels. Also a brief characterization of the different type of constraints is offered, namely the holonomic and nonholonomic constraints. The kinematic constraints described here are formulated using generalized coordinates. The chapter ends with a general approach to deal with the kinematic analysis of multibody systems.

Communications with QoS in IoT&Cloud environment

Dissertação de mestrado integrado em Engenharia de Telecomunicações e Informática