Use of recent geoid models to estimate mean dynamic topography and geostrophic currents in South Atlantic and Brazil Malvinas confluence

A utilização de modelos geoidais na determinação da Topografia Dinâmica Média foi impulsionada com o lançamento dos satélites do sistema GRACE, já que seus modelos apresentam precisão e resolução espacial e temporal sem precedentes. No presente trabalho, além do modelo de nível médio do mar DNSC08, foram utilizados os seguintes modelos geoidais com o objetivo de calcular as TDMs: EGM96, EIGEN-5C e EGM2008. No método adotado, foram calculadas as respectivas correntes geostróficas para o Atlântico Sul a partir das TDMs. O grau e ordem dos modelos geoidais influenciam diretamente na determinação da TDM e correntes. Neste trabalho verificou-se que presença de ruídos da TDM requer a utilização de técnicas de filtragem eficientes, como o filtro baseado em Singular Spectrum Analysis, que apresenta vantagens significativas em relação aos filtros convencionais. As correntes geostróficas resultantes dos modelos geoidais foram comparadas com resultados de modelo numérico hidrodinâmico HYCOM. Como principais conclusões, os resultados mostraram que as TDMs e respectivas correntes geostróficas calculadas com os modelos EIGEN-5C e EGM2008 foram similares aos resultados do modelo numérico, especialmente em relação às principais feições de grande escala, como as correntes do contorno e a retroflexão na Confluência Brasil Malvinas.The use of geoid models to estimate the Mean Dynamic Topography was stimulated with the launching of the GRACE satellite system, since its models present unprecedented precision and space-time resolution. In the present study, besides the DNSC08 mean sea level model, the following geoid models were used with the objective of computing the MDTs: EGM96, EIGEN-5C and EGM2008. In the method adopted, geostrophic currents for the South Atlantic were computed based on the MDTs. In this study it was found that the degree and order of the geoid models affect the determination of TDM and currents directly. The presence of noise in the MDT requires the use of efficient filtering techniques, such as the filter based on Singular Spectrum Analysis, which presents significant advantages in relation to conventional filters. Geostrophic currents resulting from geoid models were compared with the HYCOM hydrodynamic numerical model. In conclusion, results show that MDTs and respective geostrophic currents calculated with EIGEN-5C and EGM2008 models are similar to the results of the numerical model, especially regarding the main large scale features such as boundary currents and the retroflection at the Brazil-Malvinas Confluence

Use of recent geoid models to estimate mean dynamic topography and geostrophic currents in South Atlantic and Brazil Malvinas confluence

The use of geoid models to estimate the Mean Dynamic Topography was stimulated with the launching of the GRACE satellite system, since its models present unprecedented precision and space-time resolution. In the present study, besides the DNSC08 mean sea level model, the following geoid models were used with the objective of computing the MDTs: EGM96, EIGEN-5C and EGM2008. In the method adopted, geostrophic currents for the South Atlantic were computed based on the MDTs. In this study it was found that the degree and order of the geoid models affect the determination of TDM and currents directly. The presence of noise in the MDT requires the use of efficient filtering techniques, such as the filter based on Singular Spectrum Analysis, which presents significant advantages in relation to conventional filters. Geostrophic currents resulting from geoid models were compared with the HYCOM hydrodynamic numerical model. In conclusion, results show that MDTs and respective geostrophic currents calculated with EIGEN-5C and EGM2008 models are similar to the results of the numerical model, especially regarding the main large scale features such as boundary currents and the retroflection at the Brazil-Malvinas Confluence

Vpliv raziskovanja spolne selekcije na razumevanje evolucije pri osnovnošolcih

Several researchers and scientific institutions argue that evolution should be explored from the first school years. However, few studies have analysed primary school students’ understanding of evolutionary processes or evaluated the impact of educational activities on such knowledge. The available data: i) suggest that primary school students can learn about evolution; and ii) identify differential reproduction as the key evolution concept less often used by students to make and justify evolutionary predictions. In the present study, we evaluate the impact of an educational programme on primary school students’ level of understanding of evolution by sexual selection and on their ability to employ differential reproduction to propose and justify evolutionary predictions. An evaluation framework was applied to estimate primary school students’ level of understanding of evolution by sexual selection in third- and fourth-grade classes, before and after the students were exposed to the educational programme. A significant increase in the level of understanding of evolution by sexual selection was observed in the target classes, but not in the control classes. This result was primarily driven by a significant increase in the students’ justifications employing the concept of differential reproduction. The results suggest that activities that model and simulate biological evolution through sexual selection can contribute to primary school students’ understanding of evolutionary processes. (DIPF/Orig.

MODELOS DE REGRESSÃO LINEAR MÚLTIPLA APLICADOS À AVALIAÇÃO DE TERRENOS URBANOS - CASO DO MUNICÍPIO DE ITAQUI-RS

Este trabalho teve como objetivo identificar variáveis explicativas para a modelagem e predição do valor real (ITBI) e venal de lotes urbanos no município de Itaqui-RS utilizando o Método Comparativo Direto de Dados do Mercado, desenvolvido por regressão linear múltipla. Em uma amostra de 67 lotes foram avaliadas variáveis quantitativas: área, testada, valor do m², valor venal e valor do ITBI e variáveis qualitativas: topografia, situação e pavimentação, sendo que para cada variável foram determinados parâmetros estatísticos incluindo a distribuição de dados por assimetria, curtose, teste de normalidade de Kolmogorov-Smirnov, bem como a correlação linear de Pearson e análise de trilha, que mostra as relações de causa e efeito das variáveis explicativas sobre o valor venal e ITBI. A importância de cada variável explicativa sobre o modelo de valor venal e ITBI foi determinada pelo método stepwise. O valor venal apresentou correlação positiva, significativa (p≤0,05) e crescente com a pavimentação, testada, área e valor do m2, nessa ordem. Já o valor de ITBI apresentou correlação positiva, significativa (p≤0,05) e crescente com valor do m2 e pavimentação, nessa ordem. A análise de trilha indicou que a área e o valor do m2 possuem relação de causa e efeito sobre o valor venal e o valor do m2 e a pavimentação apresenta relação de causa e efeito sobre o valor de ITBI. Os modelos: Y=16,90×área + 594,69×valor do m2-9526,54×topografia (r2=0,91) e, Y=868,36×valor do m2 - 23642,19×topografia + 33633,46×pavimentação (r2=0,70), são adequados para a estimação dos valores venal e de ITBI, respectivamente

Influência da temperatura e do fluxo de ar sobre o consumo de ração e ganho de peso em ratos Wistar (Rattus norvegicus) mantidos em sistema microambiental

Wistar rats had been kept individually, in metabolic wire cages, without shelter, in microenvironmental system, under direct air flow at 0,6 m/s, under temperatures of 22º, 24º, 26º, 28º and 30º C. The food consumption and the weight gain had been compared in the end of 5 days (ANOVA; Tukey-Kramer). In the total, 7 groups, 10 animals each, had been compared. For the 22ºC temperature, had been used 3 groups, one experimental and two controls. One of them was kept in similar ambient of conventional laboratory animal rooms conditions (general diluitory ventilation, GDV) - C1. The other control group (C2) was kept in the interior of the equipment of microenvironmental ventilation, however, without the direct air flow, simulating the GDV. The gotten results demonstrate clearly that animal kept under direct microenvironmental ventilation at 26º, 28º and 30ºC have the same gain of corporal mass that C1 group. The groups kept at 22º and 24ºC, had less corporal mass gain when compared to C1 (p<0,001 and p<0,01 respectively). The weight gain for all the experimental groups, when compared to C2, presents statistical differences, except 30ºC group, that was equal to C2. The food consumption of all the groups was constant. Only the 30ºC group presented a reduction in the food consumption when compared with the groups C1 and C2 (p<0,05 for the two comparisons).Ratos wistar foram mantidos individualmente, em gaiolas metabólicas de arame, sem abrigo, em sistema microambiental, sob fluxo direto de ar a 0,6 m/s, nas temperaturas de 22º, 24º, 26º, 28º e 30º C. O consumo de ração e o ganho de peso foram comparados do final de 5 dias (ANOVA; Tukey-Kramer). No total, sete grupos de 10 animais cada foram comparados. Para a faixa de 22ºC foram utilizados três grupos, sendo um grupo experimental e dois grupos controles. Um deles foi mantido em condições ambientais semelhantes a biotérios convencionais sob ventilação geral diluidora (VGD) - C1. O outro grupo controle (C2) foi mantido no interior do equipamento de ventilação microambiental, porém, sem o direcionamento de ar, simulando a VGD. Os resultados obtidos demonstram claramente que animais mantidos sob ventilação microambiental direta a 26º, 28º e 30ºC apresentam o mesmo ganho de massa corpórea que animais do grupo C1. Os grupos de animais mantidos a 22º e 24ºC, apresentaram menor ganho de massa corpórea quando comparados a C1 (p<0,001 e p<0,01 respectivamente). O ganho de peso de todos os grupos experimentais, quando comparado ao C2, apresenta diferenças estatísticas, exceto o mantido a 30ºC que apresentou índice de ganho de peso equivalente a C2. O consumo de ração de todos os grupos se manteve constante. Somente o grupo E5 apresentou uma redução no consumo de ração quando comparado aos grupos C1 e C2 (p<0,05 para as duas comparações)

Proposal for a framework to evaluate elementary school students understanding of natural selection

Evolution is one of the key concepts in biology that should be explored since kindergarten. However, the few studies analysing elementary school students' learning about natural selection used distinct criteria to evaluate their knowledge. In the present work we develope a framework to evaluate students' understanding of natural selection, based on a literature review and on an empirical study. This framework can be used to assess students understanding of evolution and natural selection, to inform the development of educational activities and to assess their impact on students' understanding of these processes

Following Darwin’s footsteps: Evaluating the impact of an activity designed for elementary school students to link historically important evolution key concepts on their understanding of natural selection

While several researchers have suggested that evolution should be explored from the initial years of schooling, little information is available on effective resources to enhance elementary school students’ level of understanding of evolution by natural selection (LUENS). For the present study, we designed, implemented, and evaluated an educational activity planned for fourth graders (9 to 10 years old) to explore concepts and conceptual fields that were historically important for the discovery of natural selection. Observation field notes and students’ productions were used to analyze how the students explored the proposed activity. Additionally, an evaluation framework consisting of a test, the evaluation criteria, and the scoring process was applied in two fourth-grade classes (N = 44) to estimate elementary school students’ LUENS before and after engaging in the activity. Our results show that our activity allowed students to link the key concepts, resulting in a significant increase of their understanding of natural selection. They also reveal that additional activities and minor fine-tuning of the present activity are required to further support students’ learning about the concept of differential reproduction.info:eu-repo/semantics/publishedVersio

Controle termo-higrométrico microambiental para animais de laboratório por meio de tecnologia termoelétrica: estudo experimental para roedores de laboratório

An air conditioner for animal facilities was mounted with thermoelectric modules of Peltier effect. For heat exchange, a water dissipation system was employed.The air temperature difference (Δt) was 21 ºC, the performance was 46.02% and the power consumption was 524 W/h. The mathematical simulation of operation, with mixture of no conditioned air showed that the system can serve approximately 137 standard mouse microisolators, with water dissipation system. The thermoelectric system also showed an accuracy of ± 0.1 ºC at the experimental temperatures, which is impossible in a system of Freon Gas. We tested the following temperatures: 22º, 24º, 26º, 28º and 30 ºC, always getting stability and accuracy at any outside temperature.Um condicionador de ar para biotérios foi montado com módulos termoelétricos de efeito Peltier. Para troca térmica foram empregados dissipadores externos a água, obtendo-se Δt de 21 ºC, rendimento de 46,02%, consumo de 524 W/h. A simulação matemática de operação, com mistura de ar não condicionado, mostrou que o sistema pode servir a aproximadamente 137 microisoladores padrão rato com dissipação externa a água. O sistema termoelétrico mostrou ainda, precisão de ± 0,1 ºC, nas temperaturas experimentais, o que é impossível num sistema de freon. Foram ensaiadas as seguintes temperaturas: 22º, 24º, 26º, 28º e 30 ºC, obtendo sempre estabilidade e precisão, independentemente da temperatura ambiental onde o equipamento estava em operação

Teaching science with experimental work and computer simulations in a primary teacher education course: what challenges to promote epistemic practices?

The objective of this work is to study how teachers’ mediation can promote the development of students’ epistemic practices (EPs), in a classroom environment, using computer simulations (CS) articulated with experimental work (EW). In particular, we want to explore characteristics of teacher mediation using CS articulated with EW as a didactical approach and what EPs occur when students work in the pathway from theory (T) to the observable-world (OW), and vice-versa. We report a multi-case study with two teachers of a primary teacher education course. We use multimodal narratives (a description of what happens in the classroom, using several types of data collected) to analyse the students’ EPs and the teachers’ mediation. This analysis is made using the qualitative analysis software (NVivo 8®). The results point that the differences in the occurrences and pathways found in students’ EPs can be related to the different characteristics of teachers’ mediation. The results also point to the existence of students’ epistemic practices that were differently promoted depending on the use of CS or EW, which means an interesting complementarity between the two teaching approaches. When teachers’ mediation incorporates the use CSs articulated with EW.info:eu-repo/semantics/publishedVersio