944 resultados para Movements
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Locomotion has been a major research issue in the last few years. Many models for the locomotion rhythms of quadrupeds, hexapods, bipeds and other animals have been proposed. This study has also been extended to the control of rhythmic movements of adaptive legged robots. In this paper, we consider a fractional version of a central pattern generator (CPG) model for locomotion in bipeds. A fractional derivative D α f(x), with α non-integer, is a generalization of the concept of an integer derivative, where α=1. The integer CPG model has been proposed by Golubitsky, Stewart, Buono and Collins, and studied later by Pinto and Golubitsky. It is a network of four coupled identical oscillators which has dihedral symmetry. We study parameter regions where periodic solutions, identified with legs’ rhythms in bipeds, occur, for 0<α≤1. We find that the amplitude and the period of the periodic solutions, identified with biped rhythms, increase as α varies from near 0 to values close to unity.
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Conferência: CONTROLO’2012 - 16-18 July 2012 - Funchal
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Introdução: Por mais de uma década assumiu-se que o transverso abdominal/oblíquo interno (TrA/OI) se comportava como um ventre muscular único, pré-ativando-se bilateralmente de forma simultânea para aumentar a stiffness da coluna lombar, conferindo-lhe estabilidade segmentar durante o movimento de um dos membros superiores. À luz dos estudos atuais sabe-se que tal mecanismo não ocorre, uma vez que o TrA/OI apresenta uma ativação por mecanismo de feedforward predominantemente contralateral ao membro superior movido. Apesar de morfologicamente o TrA/OI do lado não-dominante ser mais hipertrofiado do que o do lado dominante, nada se sabe acerca da influência da dominância nos timings ativação do TrA/OI. Objectivos: Confirmar se o TrA/OI tem um timing de ativação assimétrico durante o movimento rápido de flexão do membro superior (MRMS). Pretende-se ainda avaliar se o timing de ativação do TrA/OI é influenciado pela dominância de lateralidade manual. Métodos: Efectuou-se um estudo observacional descritivo, transversal e duplamente cego com 32 atletas de futebol voluntários com membro superior direito dominante, colocando-os apenas num grupo. Procedeu-se à recolha do sinal eletromiográfico de forma a avaliar os timings de ativação do TrA/OI bilateralmente aquando dos movimentos rápidos de flexão de ambos os membros superiores, à vez. Todos os dados foram tratados estatisticamente com o programa SPSS, versão 20.0 para Mac OS, com um grau de significância de 0,05. Resultados: Verificaram-se diferenças nos timings de ativação dos TrA/OI direito e esquerdo durante os MRMS direito e esquerdo (Teste ANOVA medidas repetidas: F=291,087; p<0,001). O timing de ativação do TrA/OI direito – 29,15(13,15)ms – foi superior ao esquerdo – 4,71(17,32)ms – durante MRMS direito (Teste Post Hoc Bonferroni: p<0,001). O timing de ativação do TrA/OI esquerdo – 31,98(12,50)ms – foi superior ao direito – 12,20(17,40)ms – durante MRMS esquerdo (p<0,001). O timing de ativação do TrA/IO direito aquando do MRMS direito foi superior ao observado durante MRMS esquerdo (p<0,001). O contrário sucedeu em relação ao timing ativação do TrA/IO esquerdo (p<0,001). O timing de ativação do TrA/IO esquerdo no MRMS direito foi inferior ao do TrA/IO direito aquando do movimento com o membro esquerdo (p<0,001). O TrA/IO direito possuiu um timing de ativação no MRMS direito inferior ao do TrA/IO esquerdo aquando do movimento com o membro esquerdo (p<0,001). Conclusão: Através deste estudo pôde-se concluir que o TrA/OI contralateral ao MRMS apresenta um timing de ativação inferior ao ipsilateral e ainda que durante o MRMS dominante o TrA/OI esquerdo e direito apresentam um timing de ativação inferior ao ocorrido durante o MRMS não-dominante.
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A nationwide seroepidemiologic survey of human T. cruzi infection was carried out in Brazil from 1975 to 1980 as a joint programme of the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and the Superintendência de Campanhas (SUGAM), Ministry of Health, of Brazil. Due to the marked heterogeneity of urban populations as result of wide migratory movements in the country and since triatomine transmission of the disease occurs mostly in rural areas, the survey was limited to rural populations. The survey was based on a large cluster sampling of complete households, from randomly selected localities comprised of 10 to 500 houses, or up to 200 houses in the Amazon region. Random selection of localities and houses was permitted by a detailed mapping of every locality in the country, as performed and continuously adjusted, by SUCAM. In the selected houses duplicate samples on filter paper were collected from every resistent 1 year or older. Samples were tested in one of 14 laboratories scattered in the country by the indirect anti-IgG immunofluorescence test, with reagents produced and standardized by a central laboratory located at the Instituto de Medicina Tropical de São Paulo. A continuous quality control was performed at this laboratory, which tested duplicates of 10% to 15% of all samples examined by the collaborating laboratories. Data regarding number of sera collected, patients'age, sex, place of residence, place of birth and test result were computerized at the Department of Preventive Medicine, Medical School, University of São Paulo, São Paulo, Brazil. Serologic prevalence indices were estimated for each Municipality and mapped according to States and Territories in Brazil. Since data were already available for the State of São Paulo and the Federal District, these unities were not included in the survey.
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Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação
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Relatório da Prática Profissional Supervisionada Mestrado em Educação Pré-Escolar
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The delay produced by drug, in the process of cercaria-schistosomulum transformation, was used to verify the sensibility of different larval stages to the host cell immune responses, in vivo. The peritoneal cavity of mice, a model used for in vivo observations, was choiced for the experiments. As well characterized schistosomules, cercariae and larvae in the process of transformation were coated and arrested by host cells, and could not be recovered by simple saline washings. After 10-²M EDTA saline washings, they were released alive, with good vitality and movements. Thus, different kind of larvae in the process of adaptation of the cercaria to the host are strongly coated by immune cells, but these fail to kill the invading organisms, at least during a few hours after invasion.
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Atualmente qualquer organização que se queira manter no ativo, tem que obrigatoriamente inovar, reduzir o desperdício associado ao processo produtivo e simultaneamente simplificar as tarefas diárias dos seus colaboradores. E é sobre estes princípios que este trabalho é baseado, ou seja, pretende-se através da aplicação de ferramentas Lean, a melhoria contínua do processo de produção da Schmitt Elevadores. Numa fase inicial foi necessário um estudo dos diferentes fluxos de materiais, que permitiu a conceção do VSM (Value Stream Mapping). O VSM juntamente com o diagrama de Spaghetti permitiram a identificação de algumas das fontes de desperdício, relacionadas essencialmente com o excesso de movimentações. Considerando o âmbito do estágio, logística interna, e reunidas as causas de desperdício verificadas nesta área, procedeu-se à criação de um ciclo de entrega de materiais, por parte do operador logístico, baseado no conceito de milk run. Verificaram-se também problemas ao nível da gestão de stocks, pelo que também foi necessária intervenção nesta área. A aplicação das medidas mencionadas anteriormente irá traduzir-se em ganhos para o processo produtivo, nomeadamente, na criação de rotinas para os operadores logísticos; evitar deslocações por parte dos operadores de cada processo e manter em supermercado a quantidade suficiente de cada artigo, para fazer face à variabilidade da procura.
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Espaces et sociétés, N.79, modes de vie et société portugaise, pág. 93-106
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(l) The Pacific basin (Pacific area) may be regarded as moving eastwards like a double zip fastener relative to the continents and their respective plates (Pangaea area): opening in the East and closing in the West. This movement is tracked by a continuous mountain belt, the collision ages of which increase westwards. (2) The relative movements between the Pacific area and the Pangaea area in the W-E/E-W direction are generated by tidal forces (principle of hypocycloid gearing), whereby the lower mantle and the Pacific basin or area (Pacific crust = roof of the lower mantle?) rotate somewhat faster eastwards around the Earth's spin axis relative to the upper mantle/crust system with the continents and their respective plates (Pangaea area) (differential rotation). (3) These relative West to East/East to West displacements produce a perpetually existing sequence of distinct styles of opening and closing ocean basins, exemplified by the present East to West arrangement of ocean basins around the globe (Oceanic or Wilson Cycle: Rift/Red Sea style; Atlantic style; Mediterranean/Caribbean style as eastwards propagating tongue of the Pacific basin; Pacific style; Collision/Himalayas style). This sequence of ocean styles, of which the Pacific ocean is a part, moves eastwards with the lower mantle relative to the continents and the upper-mantle/crust of the Pangaea area. (4) Similarly, the collisional mountain belt extending westwards from the equator to the West of the Pacific and representing a chronological sequence of collision zones (sequential collisions) in the wake of the passing of the Pacific basin double zip fastener, may also be described as recording the history of oceans and their continental margins in the form of successive Wilson Cycles. (5) Every 200 to 250 m.y. the Pacific basin double zip fastener, the sequence of ocean styles of the Wilson Cycle and the eastwards growing collisional mountain belt in their wake complete one lap around the Earth. Two East drift lappings of 400 to 500 m.y. produce a two-lap collisional mountain belt spiral around a supercontinent in one hemisphere (North or South Pangaea). The Earth's history is subdivided into alternating North Pangaea growth/South Pangaea breakup eras and South Pangaea growth/North Pangaea breakup eras. Older North and South Pangaeas and their collisional mountain belt spirals may be reconstructed by rotating back the continents and orogenic fragments of a broken spiral (e.g. South Pangaea, Gondwana) to their previous Pangaea growth era orientations. In the resulting collisional mountain belt spiral, pieced together from orogenic segments and fragments, the collision ages have to increase successively towards the West. (6) With its current western margin orientated in a West-East direction North America must have collided during the Late Cretaceous Laramide orogeny with the northern margin of South America (Caribbean Andes) at the equator to the West of the Late Mesozoic Pacific. During post-Laramide times it must have rotated clockwise into its present orientation. The eastern margin of North America has never been attached to the western margin of North Africa but only to the western margin of Europe. (7) Due to migration eastwards of the sequence of ocean styles of the Wilson Cycle, relative to a distinct plate tectonic setting of an ocean, a continent or continental margin, a future or later evolutionary style at the Earth's surface is always depicted in a setting simultaneously developed further to the West and a past or earlier style in a setting simultaneously occurring further to the East. In consequence, ahigh probability exists that up to the Early Tertiary, Greenland (the ArabiaofSouth America?) occupied a plate tectonic setting which is comparable to the current setting of Arabia (the Greenland of Africa?). The Late Cretaceous/Early Tertiary Eureka collision zone (Eureka orogeny) at the northern margin of the Greenland Plate and on some of the Canadian Arctic Islands is comparable with the Middle to Late Tertiary Taurus-Bitlis-Zagros collision zone at the northern margin of the Arabian Plate.
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Proceedings of the I" R.C.A.N.S. Congress, Lisboa, October 1992
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This study identifies and describes the major Cenozoíc glyptogenesis and sedimentation episodes in the Minho region (NW Portugal). The fluvial processes of exorheic network were mainly the builders of Cenozoic landscape. This paper presents a chronological sequence of the major fluvial events based on geomorphology and sedimentary characteristics obtained in former studies and new ones. The oldest Cenozoic sedimentation (Placencian) remains on local depressions and was generated by fluvial and fluvio-lacustrine processes. Quaternary glyptogenesis begins probably with a major European cooling (Gunz?). So, the Placencian infilling was eroded and a new episode of sedimentation was accumulated in the same early paleovalley. There were three more cycles of quaternary glyptogenesis and sedimentation. The last glyptogenesis episode records the last glacial period. The post-glacial alluvion contains clasts of granites, schists, feldspats, and other alterable lithologies and minerals; on clay dimensions there are abundant illite and interstratified minerals. This composition differs from the older ones, more siliciclastic and kaolinitic. Other minor erosion episodes were identified, controlled manly by eustasy; evidences of tectonic movements were observed only in rio Minho valley.
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One of the most common characteristics of Portuguese littoral is the existence of a planed surface (the so-called "littoral platform"), situated at different altitudes and bordered from the inland by a straight relief, strongly contrasting with that planed surface. This one is generally covered with several outcrops of the so-called Plio-Pleistocene deposits. Till the eighties this platform has been interpreted as stable staircase of old marine levels, registering in a passive way the eustatic variations. The rigid step bordering it easterly should be a fossil cliff. However, our study has proved that many of these deposits have a continental origin. These continental deposits have fluvial or alluvial fan facies and they are lying above 40 meters. Marine deposits seem to be quite rare and they only occupy a small western area, beneath the altitude of 40 meters and developing into three different marine levels. There is a rigid step between the two kinds of deposits. We think that the clear geometric separation between these deposits together with this rigid step, indicates a tectonic origin. It seems that the sea must have touched only the western part of this surface, when neotectonic movements lowered it down. There are more evidences for neotectonic movements: a) there are faults (mainly inverse faults) affecting the higher deposits of this littoral platform; b) the same marine level seems to appear at different altitudes, developing an irregular pattern with a general trend dipping from the North to the South.
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In Portugal, especially starting in the 1970s, women’s studies had implications on the emergency of the concept of gender and the feminist criticism to the prevailing models about differences between sexes. Until then, women had been absent from scientific research both as subject and as object. Feminism brought more reflexivity to the scientific thinking. After the 25th of April 1974, because of the consequent political openness, several innovating themes of research emerged, together with new concepts and fields of study. However, as far as gender and science relationship is concerned, such studies especially concentrate on higher education institutions. The feminist thinking seems to have two main objectives: to give women visibility, on the one hand, and to denunciate men’s domain in the several fields of knowledge. In 1977, the “Feminine Commission” is created and since then it has been publishing studies on women’s condition and contributing to the enhancement of the reflection of female condition at all levels. In the 1980s, the growing feminisation of tertiary education (both of students and academics), favoured the development of women’s studies, especially on their condition within universities with a special focus on the glass ceiling, despite the lack of statistical data by gender, thus making difficult the analysis of women integration in several sectors, namely in educational and scientific research activities. Other agglutinating themes are family, social and legal condition, work, education, and feminine intervention on political and social movements. In the 1990s, Women Studies are institutionalised in the academic context with the creation of the first Master in Women Studies in the Universidade Aberta (Open University), in Lisbon. In 1999, the first Portuguese journal of women studies is created – “Faces de Eva”. Seminars, conferences, thesis, journals, and projects on women’s studies are more and more common. However, results and publications are not so divulgated as they should be, because of lack of comprehensive and coordinated databases. 2. Analysis by topics 2.1. Horizontal and vertical segregation Research questions It is one of the main areas of research in Portugal. Essentially two issues have been considered: - The analysis of vertical gender segregation in educational and professional fields, having reflexes on women professional career progression with special attention to men’s power in control positions and the glass ceiling. - The analysis of horizontal segregation, special in higher education (teaching and research) where women have less visibility than men, and the under-representation of women in technology and technological careers. Research in this area mainly focuses on description, showing the under-representation of women in certain scientific areas and senior positions. Nevertheless, the studies that analyze horizontal segregation in the field of education adopt a more analytical approach which focuses on the analysis of the mechanisms of reproduction of gender stereotypes, especially socialisation, influencing educational and career choices. 1