437 research outputs found
Smart Specialization (SS): Understanding the aprroach to RIS3 and a bibliometic account of SS roots and scientific literature
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The Impact of the Zika Epidemic on Women’s Reproductive Intentions and Behaviors in Brazil
This research brief reports on a focus group study that explores how and why the Zika virus affects reproductive processes in Brazil. The authors found that both reproductive intentions and behaviors changed as a result of the Zika epidemic among women from low and high socioeconomic status groups in two areas of Brazil. The authors argue that Brazilian health officials and policymakers should reduce barriers to contraceptive use, address longstanding disparities in reproductive health services that put low-income women at disproportionate risk of an unwanted pregnancy, legalize abortion, and show respect and support to women who actively pursue pregnancy during the Zika epidemic.Population Research Cente
Composição domiciliar e desempenho acadêmico no ensino fundamental no Brasil
Children with divorced parents or children living in single-parent families are expected to achieve lower academic performance in standardized tests when compared to children living with two biological parents. Nevertheless, the mechanisms of those disparities remain poorly addressed in the Brazilian literature. We compared the performance of students in the 5th-grade at the elementary level using Saeb of 2017 for Mathematics and Portuguese. The main objective was to address the differences between students living with: mother and father; mother and social father; mother only or with aggregates; father and social mother; father only or with aggregates; and other arrangements. Children living with their mother and a social father or with both biological parents had higher performances. Nonetheless, differences became insignificant when controlled by school infrastructure and location, household´s socioeconomic status and household´s social interactions. The results highlight the need for public policies to strengthen school and family resources invested on academic learning to overcome the challenges imposed by the new family configurations on children´s achievement.Espera-se que crianças com pais divorciados ou que vivam em famílias monoparentais obtenham um desempenho académico inferior em testes padronizados quando comparadas com as crianças que vivem com os dois pais biológicos. No entanto, os mecanismos dessas disparidades permanecem pouco abordados na literatura brasileira. Comparamos o desempenho dos alunos do 5º ano do ensino fundamental em Matemática e Português utilizando o Saeb de 2017. O objetivo principal foi abordar as diferenças entre os alunos que viviam com: mãe e pai; mãe e padrasto; mãe somente ou com agregados; pai e madrasta; pai somente ou com agregados; e outros arranjos. As crianças que viviam com a mãe e padrasto ou com ambos os pais biológicos tiveram desempenhos superiores. No entanto, as diferenças tornaram-se não significantes quando controladas pela infra-estrutura e localização escolar, pelo nível socioeconómico do domicílio e pelas interacções sociais no domicílio. Os resultados destacam a necessidade de políticas públicas para fortalecer os recursos escolares e familiares investidos no aprendizado acadêmica das crianças para superar os desafios impostos pelas novas configurações familiares
The Transition to Low Fertility in Brazil
In Brazil, the Total Fertility Rate went down from 4.26 children per women in 1980 to 1.91 in 2010. Internal disparities exist, however, regardless of the low value results at the macro level. For most socio-demographic groups, fertility rates are now lower than the desired family size, suggesting that women are, on average, having fewer children than they wish. In this dissertation, I use data from the Brazilian Demographic and Health Survey from 1986 and 1996, and from the Pesquisa Nacional de Demografia e Saude of 2006. I analyze these sources to decompose and analyze fertility rates using a framework that explains fertility rates at the aggregate level, based on a measurement of the Desired Family Size based on six parameters: unwanted fertility, replacements for child mortality, sex preferences, tempo effect, involuntary infertility, and competing preferences. By outlining and operationalizing these components across time, the first chapter illuminates the factors that contribute to low fertility in Brazil, and describes how they vary by socio-demographic characteristics (race, religion, education, wealth, geographic macro-region, and place of residence). For example, I find that unwanted pregnancies disproportionately affect the fertility rates for women of low education and low income. I also see that overtime, competing preferences are making women having fewer children than desired. The second chapter explores variations in gender preference for different socio-demographic groups using responses to questions about the ideal number of children and their composition available at the same databases. I present evidence of a preference for balance, although indifference regarding the composition has also been gaining momentum. I also find evidence of a secondary daughter preference that is small, but pervasive. The third chapter investigates factors that compete with childbearing. In brief, I find that women who work, have a college degree and take longer to marry are facing more challenges when it comes to having the number of children they desire. I also find that although women are postponing their fertility, they still hope to achieve it. In sum, findings from this dissertation elucidate macro-level, structural elements that explain variability in fertility outcomes, and considers the conjunctures that lead a women to either have more or fewer children than her desired target.Doctor of Philosoph
SARS-CoV-2 virus classification based on stacked sparse autoencoder
Since December 2019, the world has been intensely affected by the COVID-19 pandemic, caused by the
SARS-CoV-2. In the case of a novel virus identification, the early elucidation of taxonomic classification
and origin of the virus genomic sequence is essential for strategic planning, containment, and treatments.
Deep learning techniques have been successfully used in many viral classification problems associated
with viral infection diagnosis, metagenomics, phylogenetics, and analysis. Considering that motivation,
the authors proposed an efficient viral genome classifier for the SARS-CoV-2 using the deep neural network
based on the stacked sparse autoencoder (SSAE). For the best performance of the model, we
explored the utilization of image representations of the complete genome sequences as the SSAE input
to provide a classification of the SARS-CoV-2. For that, a dataset based on k-mers image representation
was applied. We performed four experiments to provide different levels of taxonomic classification of
the SARS-CoV-2. The SSAE technique provided great performance results in all experiments, achieving
classification accuracy between 92% and 100% for the validation set and between 98.9% and 100% when
the SARS-CoV-2 samples were applied for the test set. In this work, samples of the SARS-CoV-2 were not
used during the training process, only during subsequent tests, in which the model was able to infer the
correct classification of the samples in the vast majority of cases. This indicates that our model can be
adapted to classify other emerging viruses. Finally, the results indicated the applicability of this deep
learning technique in genome classification problems.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) 00
Premarital life plans during the transition to adulthood in the United States
This paper investigates attitudes that never married young adults (ages 17-24) hold about what is important to accomplish before getting married. Using data from the National Study of Youth and Religion (NSYR), I investigate how a range of socio-economic and demographic variables are related to a high degree of importance to particular achievements before marriage. I then provide in-depth narrative of premarital life-plans drawing on qualitative data from semi-structured interviews conducted with a subsample of NSYR survey respondents. As a result, the preparation for marriage is a diverse experience in which young adults form their strategies based on the combination and accumulation of three forms of capital: Human Capital, Identity Formation Capital, and Relationship Capital. The importance of each seems to be structured by important social institutions. Gender, religion, race/ethnicity, geographic location and family are schema-producing and help shaping what young adults think is necessary to be achieved before marriage.Master of Art
Avaliação da interferência aerodinâmica entre as pás e a torre de uma turbina eólica
Tese de mestrado, Engenharia da Energia e do Ambiente, Universidade de Lisboa, Faculdade de Ciências, 2010Devido à crise energética e problemas ambientais, houve uma forte aposta na diversificação de recursos energéticos, particularmente nas energias renováveis, de forma a assegurar a diversidade e a segurança no abastecimento de energia. A Energia eólica é uma das mais promissoras, sendo utilizada em pequena e grande escala, maioritariamente em parques eólicos capazes de gerar grande quantidade de energia. O diâmetro do rotor tem aumentado significativamente ao longo dos anos, sendo necessário estudar os efeitos adversos que ocorrem nas pás durante a sua rotação. A interferência aerodinâmica que ocorre, quando as pás de uma turbina de eixo horizontal, se encontram próximas da torre, é designada efeito sombra. Este efeito provoca um défice da velocidade do vento causado pela obstrução da torre quando cada pá passa à frente dessa no seu movimento de rotação, causando perda de potência e vibrações na estrutura. Este efeito é mais significativo quando o rotor se encontra a jusante da torre, downwind, provocando flexões nas pás e contribuindo para o seu stress, aumentando o ruído. Para as turbinas com o rotor a montante, upwind, da torre este efeito é menos significativo sentindo-se no entanto oscilações significativas nos coeficientes aerodinâmicos da pá. O presente trabalho consistiu no estudo deste efeito através de ensaios em túnel de vento dos modelos da torre e da pá, e a determinação dos coeficientes aerodinâmicos desta para o escoamento não perturbado e para o escoamento afectado pelo posicionamento da torre, numa turbina upwind, considerando várias posições relativas da trajectória da pá quando esta passa em frente à torre. Para a realização dos ensaios utilizou-se um perfil alar 2D e um cilindro cujo diâmetro e afastamento da pá foram escalados a partir da pá, tomando a dimensão da corda como referência. Finalmente foram analisados os resultados e constatada a importância desta interferência aerodinâmica.Due to the energy crises and environmental problems the latest development in the energy sector reflected a strong focus on diversification of energy resources particularly in renewable energy in order to ensure diversity and security of energy supply. Wind energy is one of the most promising, being used on small and large scale; mainly in wind farms that can generate large amounts of energy. As the rotor diameter as increased significantly over the years is necessary to study the adverse effects that occur on the blades during their rotation. The aerodynamic interference that occurs when the rotor blades, of a horizontal turbine, are closer to the wind tower is known as tower shadow effect. This effect induces a wind speed deficit caused by obstruction of the tower when each blade passes in front of it during their rotation, causing a decrease of power and induced vibrations in the structure. This effect is more significant when the rotor is located downstream of the tower, downwind, causing inflections in the blades contributing to their stress and increasing the noise. For turbines with the rotor upstream, upwind, of the tower this interference is less significant. However there are significant oscillations in the blades aerodynamic coefficients. This work is to study this effect by testing in a wind tunnel, tower and blade models and to determine blade’s aerodynamic coefficients for undisturbed flow and for the flow affected by the tower, in a upwind turbine considering various positions on the trajectory of the blade as it passes in front of the tower. For the tests we used a 2D airfoil, and a cylinder whose diameter and spacing of the blade has been scaled from the blade, taking the dimension of the chord as a reference. Finally the results confirmed the importance of aerodynamic interference
Um olhar sobre as questões culturais no curso de Ciências da Natureza
O profissional da educação necessita apropriar-se da sua ciência como base para o enfrentamento dos desafios impostos à prática docente, visando a formação de uma cultura científica. Desse modo, este trabalho surge sob a perspectiva multicultural, principalmente quando o curso superior se caracteriza por multi-áreas, como é o caso da licenciatura em Ciências da Natureza (CN). Ao considerar que o Projeto Pedagógico do Curso (PPC) de um curso representa a caracterização do perfil de egresso, importantes reflexões sobre o processo formativo podem ser elucidadas através de sua análise. Para tanto, a fim de compreender como se dá a formação para a multiculturalidade no curso citado, realizou-se uma análise documental para verificar as questões referentes à educação cultural, distribuídas ao longo das componentes curriculares de Práticas Pedagógicas (PP) do PPC do curso de CN Licenciatura. A análise dos dados consistiu em verificar presença/ausência de questões culturais nos objetivos das componentes de PP. Constatou-se que das 7 componentes de PP, que contabilizam 420 horas da matriz curricular, a presença da educação cultural está assegurada em cinco delas, sendo que a PP II contempla os aspectos culturais de forma contundente. Os resultados reforçam a necessidade de discussões e de estudos sobre os princípios norteadores do multiculturalismo considerando que a enculturação científica é uma das finalidades da educação científica
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