1000 resultados para Investigações


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O avanço das tecnologias trouxe aos meios de comunicação a oportunidade destes explorarem novas possibilidades e, também, a necessidade de se adaptarem ao ciberespaço. As revistas compõem este panorama e, com a popularização da internet, começaram a se fazer presentes na rede, ambiente ao qual chegaram com sites que reproduziam seu conteúdo e, com o tempo, aprimoraram seu modus operandi. Com o advento de dispositivos móveis, elas continuam se adequando ao ambiente digital. Sob essa perspectiva, delineia-se a presente pesquisa, que visa compreender as novas práticas jornalísticas e os modelos de negócios possíveis de serem empreendidos em tal cenário de incessantes transformações. Para tanto, realiza-se um levantamento bibliográfico e de dados estatísticos, além de um estudo de caso. A pesquisa revela condições do novo fazer jornalístico, bem como caminhos possíveis de modelos mercadológicos para as revistas nas plataformas digitais.

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Multi-objective problems may have many optimal solutions, which together form the Pareto optimal set. A class of heuristic algorithms for those problems, in this work called optimizers, produces approximations of this optimal set. The approximation set kept by the optmizer may be limited or unlimited. The benefit of using an unlimited archive is to guarantee that all the nondominated solutions generated in the process will be saved. However, due to the large number of solutions that can be generated, to keep an archive and compare frequently new solutions to the stored ones may demand a high computational cost. The alternative is to use a limited archive. The problem that emerges from this situation is the need of discarding nondominated solutions when the archive is full. Some techniques were proposed to handle this problem, but investigations show that none of them can surely prevent the deterioration of the archives. This work investigates a technique to be used together with the previously proposed ideas in the literature to deal with limited archives. The technique consists on keeping discarded solutions in a secondary archive, and periodically recycle these solutions, bringing them back to the optimization. Three methods of recycling are presented. In order to verify if these ideas are capable to improve the archive content during the optimization, they were implemented together with other techniques from the literature. An computational experiment with NSGA-II, SPEA2, PAES, MOEA/D and NSGA-III algorithms, applied to many classes of problems is presented. The potential and the difficulties of the proposed techniques are evaluated based on statistical tests.

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Multi-objective problems may have many optimal solutions, which together form the Pareto optimal set. A class of heuristic algorithms for those problems, in this work called optimizers, produces approximations of this optimal set. The approximation set kept by the optmizer may be limited or unlimited. The benefit of using an unlimited archive is to guarantee that all the nondominated solutions generated in the process will be saved. However, due to the large number of solutions that can be generated, to keep an archive and compare frequently new solutions to the stored ones may demand a high computational cost. The alternative is to use a limited archive. The problem that emerges from this situation is the need of discarding nondominated solutions when the archive is full. Some techniques were proposed to handle this problem, but investigations show that none of them can surely prevent the deterioration of the archives. This work investigates a technique to be used together with the previously proposed ideas in the literature to deal with limited archives. The technique consists on keeping discarded solutions in a secondary archive, and periodically recycle these solutions, bringing them back to the optimization. Three methods of recycling are presented. In order to verify if these ideas are capable to improve the archive content during the optimization, they were implemented together with other techniques from the literature. An computational experiment with NSGA-II, SPEA2, PAES, MOEA/D and NSGA-III algorithms, applied to many classes of problems is presented. The potential and the difficulties of the proposed techniques are evaluated based on statistical tests.

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Este texto centra-se numa experiência de aprendizagem desenvolvida numa turma de vinte e cinco alunos do quinto ano de escolaridade na exploração de relações numéricas no triângulo de Pascal, com o propósito principal de identificar e analisar processos de resolução desenvolvidos pelos alunos em tarefas de cariz mais investigativo. É possível concluir que o trabalho proporcionado por este tipo de tarefas, apelando a processos matemáticos complexos, como conjeturar e generalizar, permite aos alunos fazer aprendizagens matemáticas com compreensão.

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Este estudo tem como objetivo contribuir para a compreensão do conhecimento profissional do professor de Matemática envolvido no desenvolvimento de tarefas de investigação na sala de aula, focando-se em quatro questões orientadoras: (i) como é que os professores colocam em prática as tarefas de investigação, considerando a planificação e condução das aulas? (ii) que dificuldades sentem os professores no desenvolvimento de tarefas de investigação na sala de aula? (iii) como é que o conhecimento didático dos professores influencia o desenvolvimento de tarefas de investigação? (iv) como é que o conhecimento didático dos professores é influenciado pelo desenvolvimento de tarefas de investigação? A fundamentação teórica assenta sobre as duas grandes temáticas do estudo: o conhecimento profissional do professor, sendo discutida a sua natureza, estrutura e conteúdo, e as tarefas de investigação, das quais se aprofunda a natureza e a utilização em sala de aula. Apresenta-se ainda investigação empírica referente ao conhecimento profissional do professor envolvido no desenvolvimento de tarefas de investigação. O estudo assumiu uma abordagem interpretativa, concretizando-se através dois estudos de caso, um de uma professora de 1. ° Ciclo e outro de um professor de Matemática do 2. ° Ciclo do Ensino Básico. Estes professores trabalharam em colaboração com a investigadora sobre tarefas de investigação, que até aí não conheciam, planificando, lecionado e refletindo acerca de um conjunto de aulas com tarefas desta natureza. Foram recolhidos dados durante as sessões de trabalho referidas, bem como nas aulas e ainda em entrevistas realizadas a cada um dos professores. Uma leitura transversal dos casos permite retirar algumas conclusões. A possibilidade de enquadramento nos conteúdos programáticos parece ser o principal critério de seleção das tarefas por parte dos professores. Na planificação, é a inventariação dos conteúdos que a tarefa mobiliza a principal prioridade, na busca da redução do grau de incerteza relacionado com as eventuais reações dos alunos. Quanto à condução de tarefas de investigação, a fase de introdução foi a mais breve, tendo servido o objetivo de conduzir à compreensão do propósito da tarefa por parte dos alunos e também reforçar alguns aspetos metodológicos do trabalho investigativo. A fase de desenvolvimento da tarefa foi aquela a que o professor de 2. ° Ciclo atribuiu maior importância, embora também valorizada pela professora de 1. ° Ciclo. Aqui, os professores consideram que o seu papel é acompanhar e orientar o trabalho dos alunos, ajudando a ultrapassar possíveis obstáculos, mantendo uma atitude questionadora. Quanto à fase de discussão, a grande preocupação dos professores é garantir a compreensão das ideias apresentadas pelos alunos. No entanto, existem duas estratégias distintas: enquanto a professora de 1. ° Ciclo, que muito valorizou esta fase, estimula a interação aluno-aluno, atribuindo-lhes a responsabilidade de validar/rejeitar as conjeturas apresentadas, o professor de 2. ° Ciclo centra em si toda esta fase, assumindo a responsabilidade de corrigir as ideias apresentadas. O desenvolvimento de tarefas de investigação é influenciado pelo conhecimento didático, revelando-se determinantes o conhecimento dos alunos e da forma como aprendem e o conhecimento do processo instrucional. O desenvolvimento de tarefas de investigação influencia várias componentes do conhecimento didático do professor, permitindo-lhe fortalecer o seu conhecimento matemático, desenvolver um conhecimento mais completo dos alunos e da forma como aprendem. Por último, a prática letiva com tarefas de investigação fornece ao professor dados importantes de como planificar e conduzir tarefas de natureza aberta, de forma a tirar o máximo partido das suas potencialidades. ABSTRACT: This study’s aim is to contribute to the understanding of the professional knowledge of the Maths teacher, involved in the development of investigative tasks in the classroom, focusing four guiding questions: (i) how do teachers give practical way to the investigative tasks, having in mind the lesson plans and lesson execution? (ii) Which difficulties do the teachers face when developing the investigative tasks in the classroom? (iii) How does the teachers' didactical knowledge influence the development of the investigative tasks? (iv) How is the teachers' didactical knowledge influenced by the development of the investigative tasks? The theorical framework is based on two broad themes of the study: teacher's professional knowledge (discussing its nature, structure and contents) and the investigative tasks (whose nature and use in the classroom is deepened). Besides, empirical research in what concerns to the professional knowledge of the teacher involved in the development of investigative tasks is also added. The study assumed an interpretative approach, materialised through two case studies, one of a primary school teacher, the other of a preparatory school Maths teacher. The teachers worked in cooperation with the researcher on the investigative tasks, which, until then, they weren't familiar with, planning, teaching and thinking about a set of lessons with tasks of this kind. Data were collected during the work meetings, as well as in the lessons and also in interviews to each one of the teachers. A transversal appreciation of the cases allows us to draw some conclusions. The possibility of integrating the programmatic contents seems to be the main criteria for the selection of the tasks by the teachers. ln the planning, the main priority of the task is the inventory of contents, aiming to reduce the level of uncertainty in what concerns to eventual reactions of the students. ln what concerns to the conduction of the investigative tasks, the introduction phase was the shortest, fulfilling the aim of leading to the understanding of the proposal of the task by the students and also to reinforce some methodological aspects of the investigative work. The task's development phase was the one the preparatory school teacher dedicated more importance, though it was also valued by the primary school teacher. ln this aspect, the teachers consider that their role is to follow and lead the students’ work, helping them to overtake eventual obstacles, keeping the questioning attitude. ln what concerns the discussion phase, the big concern of the teachers is to reassure the understanding of the ideas presented by the students. However, there are two different strategies: while the primary school teacher, who really valued this phase, stimulates the student-student interaction, giving them the responsibility of validating/rejecting the presented conjectures; the preparatory school teacher centers around himself all this phase, assuming the responsibilities of correcting the presented ideas. The development of the investigative tasks is influenced by the didactical knowledge, and it is determinant the knowledge about the students and about the way they learn and the instructional knowledge. The development of the investigative tasks influences several components of the didactical knowledge of the teacher, allowing him/her to reinforce his mathematical knowledge, developing a more complete knowledge about the students and the way they learn. Finally, the lessons execution with investigative tasks provides the teacher with important data about how to plan and conduct open nature tasks, in order to take the biggest advantage of their potential.

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Brain death results in the breakdown of effective central regulatory mechanisms of cardiocirculatory stability, even in patients with artificial mechanical ventilation, correction of electrolytic and acid-basic disorders and maximal conventional pharmacological support of the circulation. Recent evidences have shown that the fall of vasopressin levels in the blood circulation significantly influences the cardiocirculatory stability of patients with brain death, and its exogenous administration is defended by many authors for the management of multiorgan donor patients. In this brief review we analyse and discuss some experimental and clinical relevant studies about the role of vasopressin in the control of cardiocirculatory stability in brain death, and its potential usefulness in the management of multiorgan donor. We conclude that the role of vasopressin in the pathophysiology of brain death and its usefulness as a pharmacological agent in the management of multiorgan donor are not well elucidated, deserving further investigations.

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Approximately 7.2% of the Atlantic rainforest remains in Brazil, with only 16% of this forest remaining in the State of Rio de Janeiro, all of it distributed in fragments. This forest fragmentation can produce biotic and abiotic differences between edges and the fragment interior. In this study, we compared the structure and richness of tree communities in three habitats - an anthropogenic edge (AE), a natural edge (NE) and the fragment interior (FI) - of a fragment of Atlantic forest in the State of Rio de Janeiro, Brazil (22°50'S and 42°28'W). One thousand and seventy-six trees with a diameter at breast height > 4.8 cm, belonging to 132 morphospecies and 39 families, were sampled in a total study area of 0.75 ha. NE had the greatest basal area and the trees in this habitat had the greatest diameter:height allometric coefficient, whereas AE had a lower richness and greater variation in the height of the first tree branch. Tree density, diameter, height and the proportion of standing dead trees did not differ among the habitats. There was marked heterogeneity among replicates within each habitat. These results indicate that the forest interior and the fragment edges (natural or anthropogenic) do not differ markedly considering the studied parameters. Other factors, such as the age from the edge, type of matrix and proximity of gaps, may play a more important role in plant community structure than the proximity from edges.

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The objectives of this work was to estimate the number of soil subsamples considering the classical statistics and geostatistics and determine the spatial variability of soil fertility attributes of an Ultisol, with clay texture, in an area of regenerating natural vegetation in Alegre - ES. Soil samples were collected in a depth of 0.0-0.2 m, at the crossing points of a regular grid, comprising a total of 64 points located at 10 m-intervals. The area presented low fertility soil. Considering a variation of 5% around the mean in the classic statistics, it is necessary a larger number of samples in relation to geostatistics. All the chemical attributes showed moderate to high spatial dependence, except for the effective cation exchange capacity (CECe), which showed pure nugget effect. The spherical semivariogram model gave the best fit to the data. Isoline maps allowed visualizing the differentiated spatial distribution of the contents of soil chemical attributes.

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The Orchidaceae is one of the largest flowering plants family and with a great importance to conservation. However, no survey on orchid flowers can be found in Mato Grosso do Sul. Thus, the objective of this work was to make a survey of the Orchidaceae species and of its ecology features in a riparian forest in a fragment of Floresta Estacional Semi-Decidual that belongs to the riparian forest of the Dourados River. The inventory was made by using a sweeping method for collection, and in addition to this the vertical and horizontal position of epiphytes were assessed on the hosts. For characterization of microclimate, it was used a thermohygrometer and luximeter. It was identified 17 species of 13 genera. Of the listed genera, the most abundant ones were: Acianthera, Macradenia and Capanemia. It was also noted a vertical and horizontal distribution of the Orchidaceae in relation to inverse gradient of water and light availability. Some species tended to be sensitive to height level categorization, whereas others seemed to occur with similar frequency along the host. In relation to the cardinal orientation, the apparent preferential response for south and east directions was associated to the low sampling effort and lower water availability, which could occur because the north face is opposed to the water body.

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Remotely sensed imagery has been widely used for land use/cover classification thanks to the periodic data acquisition and the widespread use of digital image processing systems offering a wide range of classification algorithms. The aim of this work was to evaluate some of the most commonly used supervised and unsupervised classification algorithms under different landscape patterns found in Rondônia, including (1) areas of mid-size farms, (2) fish-bone settlements and (3) a gradient of forest and Cerrado (Brazilian savannah). Comparison with a reference map based on the kappa statistics resulted in good to superior indicators (best results - K-means: k=0.68; k=0.77; k=0.64 and MaxVer: k=0.71; k=0.89; k=0.70 respectively for three areas mentioned). Results show that choosing a specific algorithm requires to take into account both its capacity to discriminate among various spectral signatures under different landscape patterns as well as a cost/benefit analysis considering the different steps performed by the operator performing a land cover/use map. it is suggested that a more systematic assessment of several options of implementation of a specific project is needed prior to beginning a land use/cover mapping job.

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Studies in several countries have shown the occurrence of forest transition, when forest cover increase overcomes the loss by deforestation. In Brazil, although deforestation is still higher than afforestation, this relationship may be inverse in some regions. Recent assessments suggest the tendency of the state of São Paulo towards forest transition. Aiming to analyze forest transition evidence and facilitate the use of existing information, we review data on native vegetation cover variation in São Paulo from four data sources (Instituto Florestal, SOS MataAtlântica/INPE, IBGE and CATI/IEA). Our results indicate that discrepancies among these assessments may be accounted by differences in methodologies and objectives. We highlight their common grounds and discuss possibilities to harmonize their information.

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The objective of this study was to evaluate the horizontal and vertical structures of tree community in regeneration in a fragment of a secondary riparian forest at approximately 30 years of age and to identify the most abundant species in each fragment of the forest to determine the sucessional stage. An area of 800 m² was subdivided into 16 samples of 10 x 5 m and all individuals with DBH ≥ 1 cm were sampled and identified for the following analyzes: horizontal parameters (DR, FR, DoR, IVC and IVI), vertical parameters (PSR and RNR) and mixed parameters, from of value of increased importance index (IVIa). The survey measured 689 individuals, belonging to 38 families, 74 genus and 109 species. The total density was 8,614 individuals/ha. The index of Shannon´s diversity was 3.99 and the index of Pielou´s equability was 0.85. Tibouchina pulchra, Psychotria suterella and Endlicheria paniculata obtained high values of IVIa. Guarea macrophylla, Gomidesia anacardiaefolia, Xylopia langsdorffiana and Endlicheria paniculata achieved high values of RNT, indicating adequate natural regeneration in the plot. The initial secondary and umbrophylous species showed the highest ecological importance in this fragment of the forest, with the highest values of sociologic position and importance index. Furthermore, the presence of late secondary species in all layers suggest that the studied fragment is in intermediate succession degree.

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The present paper brings about a possible articulation between translation and body from a non-sublimated, pragmatic perspective on meaning, as suggested by Wittgenstein in his Philosophical Investigations. By considering theoretical elaborations within embodied realism and elsewhere on the role of the body in cognitive processes, together with a critique of the concept of translation somatics, as proposed by Douglas Robinson (1991), the paper highlights the situated and social character of the translator's body.

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We present and discuss in this article some features of a research program whose central object of investigation is the way in which the recent fields of history, philosophy, and sociology of mathematical education could take part in a critical and qualified manner in the initial and continuing training of teachers in this area. For that, we endorse the viewpoint that the courses for mathematics teacher education should be based on a conception of specificity through which a new pedagogical project could be established. In such project those new fields of investigation would participate, in an organic and clarifying way, in the constitution of multidimensional problematizations of school practices, in which mathematics would be involved, and that would be guided by academic investigations about the issues that currently challenge teachers in the critical work of incorporation, resignification, production, and transmission of mathematical culture in the context of the school institution.

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This study analyses the national scientific production about college students' residence halls. The country's main data bases and electronic sites of several Brazilian higher education institutions were checked and 23 studies, published between 2000 and 2009, were found. The results of our analysis point to different focuses, which can be grouped into three categories: students who live in residence halls, residence halls themselves and actions for student assistance. Although there is large foreign scientific production about college student housing, the national production on this theme is still scarce, and the idea of student residence halls as educational spaces is still very incipient. The study points out to the need for investigating the living conditions in these places, and the impacts of this kind of habitation on students. Considering that student housing is an institutional responsibility, these studies potentially subsidize measures for proper educational conditions for college students.