952 resultados para Pre-start drop-out
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The external forces applied in swimming starts have been often studied, but using direct analysis and simple interpretation data processes. This study aimed to develop a tool for vertical and horizontal force assessment based on the swimmers' propulsive and structural forces (passive forces due to dead weight) applied during the block phase. Four methodological pathways were followed: the experimented fall of a rigid body, the swimmers' inertia effect, the development of a mathematical model to describe the outcome of the rigid body fall and its generalization to include the effects of the inertia, and the experimental swimmers' starting protocol analysed with the inclusion of the developed mathematical tool. The first three methodological steps resulted in the description and computation of the passive force components. At the fourth step, six well-trained swimmers performed three 15 m maximal grab start trials and three-dimensional (3D) kinetic data were obtained using a six degrees of freedom force plate. The passive force contribution to the start performance obtained from the model was subtracted from the experimental force due to the swimmers resulting in the swimmers' active forces. As expected, the swimmers' vertical and horizontal active forces accounted for the maximum variability contribution of the experimental forces. It was found that the active force profile for the vertical and horizontal components resembled one another. These findings should be considered in clarifying the active swimmers' force variability and the respective geometrical profile as indicators to redefine steering strategies.
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The purpose of this study was to analyse differences between total physical activity (TPA) and moderate-to-vigorous PA (MVPA) of pre-school children during daily school hours when they attended the physical education class (PED) and school days without PE class (NPED) and to assess the contribution of PE classes to TPA in school hours. The sample was composed of 193 pre-school healthy children (96 girls) aged from three to five years old and was conducted between February and December of 2008. Children wore accelerometers for at least four consecutive days during school hours. Data were analysed with specific software, age-specific counts-per-minute cut-off points and a 5 s epoch were used. Independent and general linear model repeated measures were used to assess differences between gender and differences between different days within each gender, respectively. Boys engaged more MVPA than girls (P < 0.05). During PED, pre-school children engaged significantly more in TPA and MVPA than during NPED (P < 0.05). PE class contributed, on average, 27.7% for the TPA and 32.8% of daily MVPA during PED in both gender. The results of this study suggest that structured PA such as a PE class increased the daily TPA and MVPA level of pre-school children.
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Although the issue of the out-of-plane response of unreinforced masonry structures under earthquake excitation is well known with consensus among the research community, this issue is simultaneously one of the more complex and most neglected areas on the seismic assessment of existing buildings. Nonetheless, its characterization should be found on the solid knowledge of the phenomenon and on the complete understanding of methodologies currently used to describe it. Based on this assumption, this article presents a general framework on the issue of the out-of-plane performance of unreinforced masonry structures, beginning with a brief introduction to the topic, followed by a compact state of art in which the principal methodologies proposed to assess the out-of-plane behavior of unreinforced masonry structures are presented. Different analytical approaches are presented, namely force and displacement-based, complemented with the presentation of existing numerical tools for the purpose presented above. Moreover, the most relevant experimental campaigns carried out in order to reproduce the phenomenon are reviewed and briefly discussed.
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During the last years, several studies have been made aiming to assess the out-of-plane seismic response of unreinforced stone masonry structures. This fact led to the development of a wide variety of models and approaches, ranging from simple kinematic based analytical models up to complex numerical simulations. Nevertheless, for the sake of simplicity, the out-of-plane seismic response of a masonry wall pier may be obtained by means of a simple single-degree-of-freedom system while still providing good results. In fact, despite the assumptions associated with such a simple formulation, it is also true that the epistemic uncertainty inherent with the selection of appropriate input parameters in more complex models may render them truly ineffective. In this framework, this paper focuses on the study of the out-of-plane bending of unreinforced stone masonry walls (cantilevers) by proposing a simplified analytical approach based on the construction of a linearized four-branch model, which is used to characterize the linear and nonlinear response of such structural elements through an overturning moment-rotation relationship. The formulation of the four-branch model is presented and described in detail and the meaningful parameters used for its construction are obtained from a set of experimental laboratory tests performed on six full-scale unreinforced regular sacco stone masonry specimens. Moreover, a parametric analysis aiming to evaluate the effect of these parameters’ variation on the final configuration of the model is presented and critically discussed. Finally, the results obtained from the application of the developed four-branch model on real unreinforced regular sacco stone masonry walls are thoroughly analysed and the main conclusions obtained from its application are summarized.
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The seismic assessment of the local failure modes in existing masonry buildings is currently based on the identification of the so-called local mechanisms, often associated with the out-of-plane wall behavior, whose stability is evaluated by static force-based approaches and, more recently, by some displacement-based proposals. Local mechanisms consist of kinematic chains of masonry portions, often regarded as rigid bodies, with geometric nonlinearity and concentrated nonlinearity in predefined contact regions (unilateral no-tension behavior, possible sliding with friction). In this work, the dynamic behavior of local mechanisms is simulated through multi-body dynamics, to obtain the nonlinear response with efficient time history analyses that directly take into account the characteristics of the ground motion. The amplification/filtering effects of the structure are considered within the input motion. The proposed approach is validated with experimental results of two full-scale shaking-table tests on stone masonry buildings: a sacco-stone masonry façade tested at Laboratório Nacional de Engenharia Civil and a two-storey double-leaf masonry building tested at European Centre for Training and Research in Earthquake Engineering (EUCENTRE).
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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Ciência Política e Relações Internacionais na área de especialização em Globalização e Ambiente
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The Ministry of Health's National Human Rabies Control Program advocates pre-exposure prophylaxis (PEP) for professionals involved with animals that are at risk of contracting rabies. We report an antemortem and postmortem diagnosis of rabies in a veterinarian who became infected when handling herbivores with rabies. The antemortem diagnosis was carried out with a saliva sample and a biopsy of hair follicles using molecular biology techniques, while the postmortem diagnosis used a brain sample and conventional techniques. The veterinarian had collected samples to diagnose rabies in suspect herbivores (bovines and caprines) that were subsequently confirmed to be positive in laboratory tests. After onset of classic rabies symptoms, saliva and hair follicles were collected and used for antemortem diagnostic tests and found to be positive by RT-PCR. Genetic sequencing showed that the infection was caused by variant 3 (Desmodus rotundus), a finding confirmed by tests on the brain sample. It is essential that professionals who are at risk of infection by the rabies virus undergo pre-exposure prophylaxis. This study also confirms that molecular biology techniques were used successfully for antemortem diagnosis and therefore not only allow therapeutic methods to be developed, but also enable the source of infection in human rabies cases to be identified accurately and quickly.
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Crowdsourcing innovation intermediaries are organizations that mediate the communication and relationship between companies that aspire to solve some problem or to take advantage of any business opportunity with a crowd that is prone to give ideas based on their knowledge, experience and wisdom. A significant part of the activity of these intermediaries is carried out by using a web platform that takes advantage of web 2.0 tools to implement its capabilities. Thus, ontologies are presented as an appropriate strategy to represent the knowledge inherent to this activity and therefore the accomplishment of interoperability between machines and systems. In this paper we present an ontology roadmap for developing crowdsourcing innovation ontology of the intermediation process. We start making a literature review on ontology building, analyze and compare ontologies that propose the development from scratch with the ones that propose reusing other ontologies, and present the criteria for selecting the methodology. We also review enterprise and innovation ontologies known in literature. Finally, are taken some conclusions and presented the roadmap for building crowdsourcing innovation intermediary ontology.
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Dissertação para obtenção do Grau de Doutor em Conservação e Restauro, especialidade Ciências da Conservação
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TB is currently considered to be the most important infectious disease among HIV-1-infected subjects in developing countries, such as Brazil. A retrospective analysis of TB cases was performed, occurring from January 1995 to December 2010 in our cohort of 599 HIV positive patients. The primary outcome was the occurrence of active TB. Forty-one TB cases were diagnosed over this period of 16 years, among 599 HIV positive patients in an open cohort setting in the city of Sao Paulo, Brazil. All-time lowest mean CD4 T cell count at the time of TB diagnosis was 146 and 186 cells/mm³, respectively. The mean HIV viral load was 5.19 log10 copies/mL, and 59% of the patients were on HAART. TB incidence was 1.47 per 100 person-years, for a total follow-up time of 2775 person-years. The probability of surviving up to 10 years after diagnosis was 75% for TB patients as opposed to 96% for patients with other, non-TB opportunistic diseases (p = 0.03). TB can be considered a public health problem among people living with HIV in Brazil despite of the widespread use of antiretrovirals for the treatment of HIV infection/AIDS.
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Trabalho de Projeto de Mestrado apresentado ao Instituto Superior de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Empreendedorismo e Internacionalização sob orientação da Doutora Celsa Maria Carvalho Machado
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Health safety during trips is based on previous counseling, vaccination and prevention of infections, previous diseases or specific problems related to the destination. Our aim was to assess two aspects, incidence of health problems related to travel and the traveler's awareness of health safety. To this end we phone-interviewed faculty members of a large public University, randomly selected from humanities, engineering and health schools. Out of 520 attempts, we were able to contact 67 (12.9%) and 46 (68.6%) agreed to participate in the study. There was a large male proportion (37/44, 84.1%), mature adults mostly in their forties and fifties (32/44, 72.7%), all of them with higher education, as you would expect of faculty members. Most described themselves as being sedentary or as taking occasional exercise, with only 15.9% (7/44) taking regular exercise. Preexisting diseases were reported by 15 travelers. Most trips lasted usually one week or less. Duration of the travel was related to the destination, with (12h) or longer trips being taken by 68.2% (30/44) of travelers, and the others taking shorter (3h) domestic trips. Most travelling was made by air (41/44) and only 31.8% (14/44) of the trips were motivated by leisure. Field research trips were not reported. Specific health counseling previous to travel was reported only by two (4.5%). Twenty seven of them (61.4%) reported updated immunization, but 11/30 reported unchecked immunizations. 30% (9/30) reported travel without any health insurance coverage. As a whole group, 6 (13.6%) travelers reported at least one health problem attributed to the trip. All of them were males travelling abroad. Five presented respiratory infections, such as influenza and common cold, one neurological, one orthopedic, one social and one hypertension. There were no gender differences regarding age groups, destination, type of transport, previous health counseling, leisure travel motivation or pre-existing diseases. Interestingly, the two cases of previous health counseling were made by domestic travelers. Our data clearly shows that despite a significant number of travel related health problems, these highly educated faculty members, had a low awareness of those risks, and a significant number of travels are made without prior counseling or health insurance. A counseling program conducted by a tourism and health professional must be implemented for faculty members in order to increase the awareness of travel related health problems.
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Nos últimos anos tem-se verificado a constante evolução dos mercados em plataformas na Internet como forma de melhoria não só dos serviços prestados, mas também para o aumento de vendas de produtos e respetiva internacionalização dos mesmos. Este aumento da procura por este tipo de softwares, assim como a constante evolução e atualização dos mesmos tem contribuído para que estas aplicações evoluam em termos de funcionalidades e complexidade. Isto contribui cada vez para a dificuldade de formar equipas capazes de manter e desenvolver estes sistemas sem que comprometa em grandes custos para as organizações. Neste sentido surgiram diversas ferramentas que permitem criar soluções pré desenvolvidas de aplicações na Internet denominadas de "E-commerce applications". Estas plataformas, apesar do utilizador não ter obrigatoriamente que deter conhecimentos de programação para proceder à sua instalação, são bastante restritas tanto aos serviços que podem ser usados, e na sua escalabilidade, visto que normalmente correm em servidores específicos e por vezes as configurações necessárias para instalação tornam-se bastante complexas de ser efetuadas. Pretende-se no âmbito desta dissertação de mestrado propor um modelo de uma arquitetura de um sistema baseado em mecanismos MDA para a área de retalho, particularmente em ambientes de e-commerce. Serão inicialmente sistematizados os principais tipos de ecommerce numa perspetiva de evolução histórica. Será igualmente enquadrado o MDA no desenvolvimento de um sistema de e-commerce. Neste sentido, serão equacionadas as diferenças entre o modelo típico de desenvolvimento de software e o desenvolvimento de software orientado pelas metodologias do MDA. No processo de especificação e desenvolvimento do modelo proposto será realizada uma análise de requisitos, assim como, a proposta do modelo da arquitetura de um sistema baseado em mecanismos MDA, tendo como orientação os requisitos e arquitetura definida na fase de análise. Finalmente no sentido de analisar o resultado esperado para um sistema orientado por metodologias definidas por MDA, serão realizado alguns testes no sistema desenvolvido de forma a analisar o seu desempenho e validar a sua adequabilidade no âmbito do processo de desenvolvimento de sistemas e-commerce
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Com o presente trabalho pretende-se avaliar a segurança de um elemento estrutural de um edifício antigo (tradicional) da baixa da Porto edificado nos finais do última quartel do século XVIII. Após uma pequena introdução onde será exposta a estrutura do trabalho, capítulo a capítulo, será feita uma explanação histórica sobre o meio urbano onde o edifício está construído, os métodos construtivos adotados desde 1755 até aos nossos dias, passando pelo historial do próprio edificado. Passar-se-á de seguida à análise do edifício, apresentando evidências do que eventualmente terá sido construído de base até aos dias de hoje. Será feita uma apresentação dos elementos construtivos que compõe actualmente o edificio, apresentando evidências do estado de cada um, ou seja, será feita um levantamento das patologias evidentes e visíveis a olho nu, recorrendo a métodos expeditos de análise. Também será feito um levantamento dimensional da volumetria , planimétria do edifício e da compartimentação, registando as dimensões dos elementos estruturais e arquitectónicos relevantes para a realização dos respectivos projectos. Posteriormente passar-se-á para uma exposição dos diversos tipos de ensaios, começando pela apresentação dos métodos disponíveis atualmente para a caracterização física e mecânica dos materiais, seguida da realização dos ensaios, recolha de dados no edificado e proposta de definição dos materiais. Após a recolha de todos estes elementos, estão reunidas as condições para se passar a uma análise estrutural, onde para estes objectivos, serão aplicados os mais avançados programas de cálculo estrutural existentes na actualidade, suportados em metodologias que analisam não só o elemento mas também a sua interação com os que lhe servem de fronteira acabando-se num todo que é o edifício. Pretende-se com este estudo estrutural avaliar a segurança de uma parte significativa e representativa do edifico baseado na regulamentação em vigor. A parte a analisar representa o pavimento aplicado na construção. Finalizar-se-á com a apresentação das conclusões, propondo eventuais ações futuras.