2,616 research outputs found

    A METODOLOGIA DE PESQUISA: METASSÍNTESE QUALITATIVA

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    Qualitative meta-synthesis is one of the modalities of bibliographic research that carry out systematic reviews, being important for the search and definition of some aspects of the research area. It identifies the possible improvements that can be made in theories, methodologies and research trends, while also looking at which aspects need to be addressed and more explicit. The article presents the definition of what is qualitative metasynthesis mentioned by authors such as Vosgerau and Romanowski, Romanowski and Ens, Fiorentini, Maranhão and Manrique e Matheus. It addresses its benefits by highlighting the positive aspects of its achievement and its limitations. This is how this research methodology can be performed, showing some steps cited by author Matheus. It also proposes reflections bringing as some investigations carried out their investigations using this methodology of research.La metasíntesis cualitativa es una de las modalidades de investigación bibliográfica que realizan revisiones sistemáticas, siendo importante para la búsqueda y definición de algunos aspectos del área de investigación. Identifica las posibles mejoras que pueden realizarse en las teorías, las metodologías y las tendencias de investigación, observando aún qué aspectos necesitan ser abordados y profundizados. El artículo presenta la definición de lo que es metasíntesis cualitativa mencionada por autores como Vosgerau y Romanowski, Romanowski y Ens, Fiorentini, Maranhão y Manrique; y Matheus. Aborda sus beneficios evidenciando los aspectos positivos para su realización,así como sus limitaciones. Así presenta como esta metodología de investigación puede ser realizada, mostrando algunas etapas citadas por la autora Matheus. También refleja como algunas investigaciones realizaron esta metodología de averiguación.A metassíntese qualitativa é uma das modalidades de pesquisa bibliográfica que executam revisões sistemáticas, sendo importante para a busca e definição de alguns aspectos da área de investigação. Identifica as possíveis melhorias que podem ser efetuadas nas teorias, nas metodologias e nas tendências de investigação, observando ainda quais aspectos necessitam ser abordados e aprofundados. O artigo contém a definição do que é metassíntese qualitativa, mencionada por autores como Vosgerau e Romanowski, Romanowski e Ens, Fiorentini, Maranhão e Manrique e Matheus. Aborda os seus benefícios, evidenciando os aspectos positivos para sua realização, assim como suas limitações. Portanto, apresenta como essa metodologia de pesquisa pode ser realizada, mostrando algumas etapas citadas por Matheus. Propõe ainda reflexões, trazendo como algumas investigações implementaram suas investigações usando essa metodologia de pesquisa

    Metassíntese Qualitativa dos Referenciais Teóricos na Formação de Professores no Campo Multiplicativo

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    Este artigo investiga os referenciais teóricos que sustentam pesquisas brasileiras, publicadas entre 1997 e 2015, relativas à formação contínua de professores dos anos iniciais do Ensino Fundamental sobre o Campo Conceitual Multiplicativo. Para sua realização, fizemos uma metassíntese qualitativa. A seleção de pesquisas ocorreu a partir do site do Banco de Teses da Capes, mediante uso de expressões relacionadas ao objetivo do estudo, obtendo, por meio de filtros, 27 pesquisas. Com este grupo, buscamos os referenciais teóricos mais citados pelas investigações: Shulman e Vergnaud. Foram encontradas nove pesquisas que utilizaram os dois referenciais teóricos, passando a ser este o corpus para a realização de uma metassíntese qualitativa. Os resultados indicam que há aspectos teóricos que não são abordados pelas investigações como: o modelo de raciocínio e ação de Shulman e o aprofundamento das situações-problema de Vergnaud

    Social determinants of dental treatment needs in Brazilian adults.

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    The chronic cumulative nature of caries makes treatment needs a severe problem in adults. Despite the fact that oral diseases occur in social contexts, there are few studies using multilevel analyses focusing on treatment needs. Thus, considering the importance of context in explaining oral health related inequalities, this study aims to evaluate the social determinants of dental treatment needs in 35-44 year old Brazilian adults, assessing whether inequalities in needs are expressed at individual and contextual levels

    Elastic properties of graphyne-based nanotubes

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    Graphyne nanotubes (GNTs) are nanostructures obtained from rolled up graphyne sheets, in the same way carbon nanotubes (CNTs) are obtained from graphene ones. Graphynes are 2D carbon-allotropes composed of atoms in sp and sp2 hybridized states. Similarly to conventional CNTs, GNTs can present different chiralities and electronic properties. Because of the acetylenic groups (triple bonds), GNTs exhibit large sidewall pores that influence their mechanical properties. In this work, we studied the mechanical response of GNTs under tensile stress using fully atomistic molecular dynamics simulations and density functional theory (DFT) calculations. Our results show that GNTs mechanical failure (fracture) occurs at larger strain values in comparison to corresponding CNTs, but paradoxically with smaller ultimate strength and Young's modulus values. This is a consequence of the combined effects of the existence of triple bonds and increased porosity/flexibility due to the presence of acetylenic groups

    Covid-19 Dynamic Monitoring and Real-Time Spatio-Temporal Forecasting

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    Background: Periodically, humanity is often faced with new and emerging viruses that can be a significant global threat. It has already been over a century post—the Spanish Flu pandemic, and we are witnessing a new type of coronavirus, the SARS-CoV-2, which is responsible for Covid-19. It emerged from the city of Wuhan (China) in December 2019, and within a few months, the virus propagated itself globally now resulting more than 50 million cases with over 1 million deaths. The high infection rates coupled with dynamic population movement demands for tools, especially within a Brazilian context, that will support health managers to develop policies for controlling and combating the new virus. / Methods: In this work, we propose a tool for real-time spatio-temporal analysis using a machine learning approach. The COVID-SGIS system brings together routinely collected health data on Covid-19 distributed across public health systems in Brazil, as well as taking to under consideration the geographic and time-dependent features of Covid-19 so as to make spatio-temporal predictions. The data are sub-divided by federative unit and municipality. In our case study, we made spatio-temporal predictions of the distribution of cases and deaths in Brazil and in each federative unit. Four regression methods were investigated: linear regression, support vector machines (polynomial kernels and RBF), multilayer perceptrons, and random forests. We use the percentage RMSE and the correlation coefficient as quality metrics. / Results: For qualitative evaluation, we made spatio-temporal predictions for the period from 25 to 27 May 2020. Considering qualitatively and quantitatively the case of the State of Pernambuco and Brazil as a whole, linear regression presented the best prediction results (thematic maps with good data distribution, correlation coefficient >0.99 and RMSE (%) <4% for Pernambuco and around 5% for Brazil) with low training time: [0.00; 0.04 ms], CI 95%. / Conclusion: Spatio-temporal analysis provided a broader assessment of those in the regions where the accumulated confirmed cases of Covid-19 were concentrated. It was possible to differentiate in the thematic maps the regions with the highest concentration of cases from the regions with low concentration and regions in the transition range. This approach is fundamental to support health managers and epidemiologists to elaborate policies and plans to control the Covid-19 pandemics

    COVID-SGIS: A Smart Tool for Dynamic Monitoring and Temporal Forecasting of Covid-19

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    Background: The global burden of the new coronavirus SARS-CoV-2 is increasing at an unprecedented rate. The current spread of Covid-19 in Brazil is problematic causing a huge public health burden to its population and national health-care service. To evaluate strategies for alleviating such problems, it is necessary to forecast the number of cases and deaths in order to aid the stakeholders in the process of making decisions against the disease. We propose a novel system for real-time forecast of the cumulative cases of Covid-19 in Brazil. / Methods: We developed the novel COVID-SGIS application for the real-time surveillance, forecast and spatial visualization of Covid-19 for Brazil. This system captures routinely reported Covid-19 information from 27 federative units from the Brazil.io database. It utilizes all Covid-19 confirmed case data that have been notified through the National Notification System, from March to May 2020. Time series ARIMA models were integrated for the forecast of cumulative number of Covid-19 cases and deaths. These include 6-days forecasts as graphical outputs for each federative unit in Brazil, separately, with its corresponding 95% CI for statistical significance. In addition, a worst and best scenarios are presented. / Results: The following federative units (out of 27) were flagged by our ARIMA models showing statistically significant increasing temporal patterns of Covid-19 cases during the specified day-to-day period: Bahia, Maranhão, Piauí, Rio Grande do Norte, Amapá, Rondônia, where their day-to-day forecasts were within the 95% CI limits. Equally, the same findings were observed for Espírito Santo, Minas Gerais, Paraná, and Santa Catarina. The overall percentage error between the forecasted values and the actual values varied between 2.56 and 6.50%. For the days when the forecasts fell outside the forecast interval, the percentage errors in relation to the worst case scenario were below 5%. / Conclusion: The proposed method for dynamic forecasting may be used to guide social policies and plan direct interventions in a cost-effective, concise, and robust manner. This novel tools can play an important role for guiding the course of action against the Covid-19 pandemic for Brazil and country neighbors in South America

    Median ages at stages of sexual maturity and excess weight in school children

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    Abstract: Background: We aimed to estimate the median ages at specific stages of sexual maturity stratified by excess weight in boys and girls. Materials and method. This was a cross-sectional study made in 2007 in Florianopolis, Brazil, with 2,339 schoolchildren between 8 to 14 years of age (1,107 boys) selected at random in two steps (by region and type of school). The schoolchildren were divided into: i) those with excess weight and ii) those without excess weight, according to the WHO 2007 cut-off points for gender and age. Sexual maturity was self-evaluated by the subjects according to the Tanner sexual development stages, and utilizing median ages for the genitalia, breasts, and pubic hair stages. Results: In the boys with excess weight, precocity was observed in the stages 4 for genitals and pubic hair and 2 for pubic hair, with the values for excess and normal weight. The median ages at the beginning of puberty (stage 2–sexual development) for boys and girls in Florianopolis were 10.8 and 10.3 years, respectively. Conclusion: Excess weight is associated with lower median ages in the sexual maturity stages in boys and girls and that it should be taken into account when evaluating sexual maturity in children and adolescents.The funding body provided financial support to make all procedures and in the decision to submit the manuscript for publication

    Clinical and histologic features of botryoid odontogenic cyst: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The lateral periodontal cyst, as the name implies, occurs on a lateral periodontal location and is of developmental origin, arising from cystic degeneration of clear cells of the dental lamina. A botryoid odontogenic cyst is considered to be a rare multilocular variant of a lateral periodontal cyst.</p> <p>Case presentation</p> <p>We report the clinical and histopathologic features of a rare case of botryoid odontogenic cyst found in an edentulous area corresponding to the right lower canine of a 64-year-old African-American woman. A multilocular radiolucency was observed, and surgical removal of the lesion revealed a nodule of rubber-like consistency measuring about 1.5 cm in diameter. Cross-sectioning of the nodule showed that it consisted of various cystic compartments. Histologically, various voluminous periodic acid-Schiff-negative clear cells randomly distributed throughout the cystic epithelium were observed, as well as cell layers showing thickenings generally formed by oval, sometimes entangled plaques. The capsule consisted of fibrous connective tissue and showed rare and discrete foci of a perivascular mononuclear inflammatory infiltrate and reactive bone-tissue fragments. The final diagnosis was botryoid odontogenic cyst.</p> <p>Conclusion</p> <p>We provide data that allow the reader to establish the differences between botryoid odontogenic cyst, glandular odontogenic cyst, and lateral periodontal cyst, helping with the differential diagnosis. The reader will have the opportunity to review botryoid odontogenic cyst clinical and histopathologic features, including treatment.</p

    Comparative cytogenetic analysis of two grasshopper species of the tribe Abracrini (Ommatolampinae, Acrididae)

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    The grasshopper species Orthoscapheus rufipes and Eujivarus fusiformis were analyzed using several cytogenetic techniques. The karyotype of O. rufipes, described here for the first time, had a diploid number of 2n = 23, whereas E. fusiformis had a karyotype with 2n = 21. The two species showed the same mechanism of sex determination (XO type) but differed in chromosome morphology. Pericentromeric blocks of constitutive heterochromatin (CH) were detected in the chromosome complement of both species. CMA3/DA/DAPI staining revealed CMA3-positive blocks in CH regions in four autosomal bivalents of O. rufipes and in two of E. fusiformis. The location of active NORs differed between the two species, occurring in bivalents M6 and S9 of O. rufipes and M6 and M7 of E. fusiformsi. The rDNA sites revealed by FISH coincided with the number and position of the active NORs detected by AgNO3 staining. The variability in chromosomal markers accounted for the karyotype differentiation observed in the tribe Abracrini
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