1,933 research outputs found

    Validação de seqüências didáticas : uma abordagem CTS no ensino da Química

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    Este estudo visa validar externa e internamente uma seqüência didática (SD) com abordagem CTS (Ciência-Tecnologia-Sociedade) no ensino de química, a partir de uma estrutura analítica focada na análise de atividades e ações realizadas na sala de aula, buscando identificar fatores de sucesso/insucesso e possíveis implicações desses fatores na trajetória de aprendizagem dos alunos. A validação externa e interna apontou aspectos relevantes na SD proposta e para a trajetória de aprendizagem dos alunos, indicando como fatores de sucesso: a diversidade e quantidade de ações realizadas por alunos, na abordagem de aspectos científicos e sociais (CTS), e ações motivadoras que possibilitaram generalização, independência e consciência com relação aos conteúdos estudados. A estrutura analítica proposta foi eficiente para a validação da SD, em um nível macro e micro de análise

    Sistema altenativo de criação de aves caipiras (SACAC): núcleo de multiplicação de galinhas.

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    A introdução de aves comerciais advindas de plantéis de raças melhoradas estão contribuindo de forma negativa com a conservação dos nossos recursos genéticos. A grande maioria dessas aves é híbrida e não adaptada às nossas condições ambientais, além de não apresentar produtos com as mesmas peculiaridades das nossas galinhas genuinamente caipiras. Ao contrário das nossas galinhas “caipiras” que são bastante rústicas, tolerantes às adversidade climáticas e resistentes a um grande número de doenças, a continuação da aquisição comercial dessas aves melhoradas tornará o agricultor familiar dependente dessas corporações e incubatórios multinacionais, além de contribuir significativamente com o aumento nos custos de produção. O aproveitamento racional dos nossos recursos naturais renováveis, como ingredientes dietéticos, medicamentos e material para construção de instalações e confecção de equipamentos, abre um mercado consistente na área da agroecologia, o que certamente resultará numa maior e melhor remuneração da nossa produção. Com a conservação e purificação dos nossos recursos genéticos, dentro de pouco tempo poderemos tanto suprir o mercado interno por meio dos módulos de multiplicação, como será possível colocar à disposição dos criadores aves mais competitivas tanto em termos de desempenho produtivo como em composição corporal e de ovos. O próximo passo será com certeza a geração das nossas primeiras raças de galinhas caipiras.bitstream/item/83434/1/Doc-174-Sistema-alternativo-de-criacao-de-aves-caipira.pd

    Health and Economic Burden of the 2017 Portuguese Extreme Wildland Fires on Children

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    Wildland fires release substantial amounts of hazardous contaminants, contributing to a decline in air quality and leading to serious health risks. Thus, this study aimed to understand the contributions of the 2017 extreme wildland fires in Portugal on children health, compared to 2016 (with burned area, in accordance with the average of the previous 15 years). The impact of long-term exposure to PM10 and NO2 concentrations, associated with wildland fires, on postneonatal mortality, bronchitis prevalence, and bronchitis symptoms in asthmatic children was estimated, as well as the associated costs. The excess health burden in children attributable to exposure to PM10 and NO2, was calculated based on WHO HRAPIE relative risks. Fire emissions were obtained from the Fire INventory from NCAR (FINN). The results obtained indicate that the smoke from wildfires negatively impacts children's lung function (PM10 exposure: increase of 320 and 648 cases of bronchitis in 2016 and 2017; NO2 exposure: 24 and 40 cases of bronchitis symptoms in asthmatic children in 2016 and 2017) and postneonatal mortality (PM10 exposure: 0.2 and 0.4 deaths in 2016 and 2017). Associated costs were increased in 2017 by around 1 million (sic) for all the evaluated health endpoints, compared to 2016

    NUMERICAL ANALYSES OF OPENFOAM'S OVERTOPPING DEVICE SOLUTION

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    Studies related to ocean energy are getting more important lately, once world claims for renewable energy usage. The Overtopping Device is a kind of Ocean Waves Energy Converter (OWEC), which main concept is storing water provided by incident waves above sea level to feed a set of low head turbines. In order to obtain the desired effect, this device contains a ramp which elevates the incident waves toward the reservoir. Present study aims to perform a numerical model of a 2D Overtopping Device by means of OpenFOAM simulations. OpenFOAM is a free open source code which has shown applicability in many areas of engineering. The adopted solver (InterFOAM) is Volume of Fluid based (VOF) according to Finite Volume Method (FVM), these methodologies has been largely used among researchers in propagating waves field. FLUENT (commercial code) is used to verify OpenFOAM's results. Once, the main point of this paper is to present OpenFOAM as a considerable tool for propagating waves studies, it firstly presents a numerical wave verification with analytical solutions (second order Stokes theory). The second section of results presents overtopping time series peaks in 100 s of simulation. Also, by mass flow rate integration, it presents total mas of water climbed to the reservoir. The integration of mass flow rate takes 94 s of simulation (not 100 s) because it is noticeable a pause between two peaks of overtopping at that time. Results show agreement between wave elevation and wave velocity profiles with straight convergence of periods between analytical and numerical waves. Most important differences are found near air/water interface, owed to faster air flow at that region. Generally OpenFOAM and FLUENT results are similar, with converged overtopping time series peaks and their magnitudes too. Similarly, the amount of water marked by both software are close with very similar trend lines

    Reduced-risk insecticides in Neotropical stingless bee species: impact on survival and activity

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    Background: As honeybees are the main pollinator species subject to an intense research regarding effects of pesticides, other ecologically important native bee pollinators have received little attention in ecotoxicology and risk assessment of pesticides in general, and insecticides in particular, some of which are perceived as reduced-risk compounds. Here the impact of three reduced-risk insecticides – azadirachtin, spinosad, and chlorantraniliprole – was assessed in two species of stingless bees, Partamona helleri and Scaptotrigona xanthotrica, which are important native pollinators in Neotropical America. The neonicotinoid imidacloprid was used as a positive control.Results: Spinosad exhibited high oral and contact toxicities in adult workers of both species at the recommended label rates, with median survival times (LT50s) ranging from 1 to 4 h, whereas these estimates were below 15 min for imidacloprid. Azadirachtin and chlorantraniliprole exhibited low toxicity at the recommended label rates, with negligible mortality that did not allow LT50 estimation. Sublethal behavioral assessments of these two insecticides indicated that neither one of them affected the overall group activity of workers of the two species. However, both azadirachtin and chlorantraniliprole impaired individual flight take-off of P. helleri and S. xanthotrica worker bees, which may compromise foraging activity, potentially leading to reduced colony survival.Conclusion: These findings challenge the common perception of non-target safety of reduced-risk insecticides and bioinsecticides, particularly regarding native pollinator species.Keywords: behavioral impact; biopesticides; colony and individual level effects; native bee pollinators; sublethal effect

    Continental-scale surface reflectance product from CBERS-4 MUX data: Assessment of atmospheric correction method using coincident Landsat observations

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    A practical atmospheric correction algorithm, called Coupled Moderate Products for Atmospheric Correction (CMPAC), was developed and implemented for the Multispectral Camera (MUX) on-board the China-Brazil Earth Resources Satellite (CBERS-4). This algorithm uses a scene-based processing and sliding window technique to derive MUX surface reflectance (SR) at continental scale. Unlike other optical sensors, MUX instrument imposes constraints for atmospheric correction due to the absence of spectral bands for aerosol estimation from imagery itself. To overcome this limitation, the proposed algorithm performs a further processing of atmospheric products from Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) sensors as input parameters for radiative transfer calculations. The success of CMPAC algorithm was fully assessed and confirmed by comparison of MUX SR data with the Landsat-8 OLI Level-2 and Aerosol Robotic Network (AERONET)-derived SR products. The spectral adjustment was performed to compensate for the differences of relative spectral response between MUX and OLI sensors. The results show that MUX SR values are fairly similar to operational Landsat-8 SR products (mean difference \u3c 0.0062, expressed in reflectance). There is a slight underestimation of MUX SR compared to OLI product (except the NIR band), but the error metrics are typically low and scattered points are around the line 1:1. These results suggest the potential of combining these datasets (MUX and OLI) for quantitative studies. Further, the robust agreement of MUX and AERONET-derived SR values emphasizes the quality of moderate atmospheric products as input parameters in this application, with root-mean-square deviation lower than 0.0047. These findings confirm that (i) CMPAC is a suitable tool for estimating surface reflectance of CBERS MUX data, and (ii) ancillary products support the application of atmospheric correction by filling the gap of atmospheric information. The uncertainties of atmospheric products, negligence of the bidirectional effects, and two aerosol models were also identified as a limitation. Finally, this study presents a framework basis for atmospheric correction of CBERS-4 MUX images. The utility of CBERS data comes from its use, and this new product enables the quantitative remote sensing for land monitoring and environmental assessment at 20 m spatial resolution

    Development of methodologies for virus detection in soybean and wheat seeds.

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    Seeds that contain large amounts of oil, starch, fibers and phenols are the most difficult tissues for RNA extraction. Currently, there are some reports of virus detection in seeds using commercial kits for RNA extraction. However, individual seeds were used, which may not be always suitable for analyses that deal with large amounts of seeds. Sangha [1] described a simple, quick and efficient protocol for RNA extraction and downstream applications in a group of seeds of jatropha (Jatropha curcas), mustard (Brassica sp.) and rice (Oryza sativa). We tested this protocol for soybean (Glycine max), maize (Zea mays), wheat (Triticum aestivum) and triticale (×Triticosecale) seeds and further reverse transcription PCR (RT-PCR)/quantitative real-time PCR (qPCR) in order to have a faster and more practical method for virus detection from seeds than the traditional scheme of seed planting and subsequent Elisa/RT-PCR from leaves. The essential points in the method are: • Some modifications in the protocol [1] were done in order to increase performance: Wheat and triticale seeds are incubated with water prior to maceration. An amount of 1.2 g of dry soybean seeds is used to maceration. • RT-PCR is used for detection of Wheat streak mosaic virus from wheat seeds and RT-qPCR for detection of Soybean mosaic virus from soybean seeds. • The method may be tested for other viruses, however, pre-validation will be needed

    Variabilidade fenotípica e genotípica em galinhas caipiras (Gallus gallus domesticus): resultados preliminares.

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    O presente trabalho teve como objetivo a avaliação preliminar da variabilidade fenotípica presente nessas aves e a seleção de marcadores moleculares, microssatélites ancorados (ISSR), para análise da variabilidade genética...bitstream/item/80683/1/circular-46.PD

    Genetic association of variations in the kappa-casein and beta-lactoglobulin genes with milk traits in girolando cattle.

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    Made available in DSpace on 2019-12-30T18:13:12Z (GMT). No. of bitstreams: 1 RrevBrasSPAMartaGenetic.pdf: 131332 bytes, checksum: b33cda6d68a0a1b815ecb7811a132abe (MD5) Previous issue date: 2019bitstream/item/207946/1/RrevBrasSPA-Marta-Genetic.pd

    A coalgebraic perspective on logical interpretations

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    In Computer Science stepwise refinement of algebraic specifications is a well-known formal methodology for rigorous program development. This paper illustrates how techniques from Algebraic Logic, in particular that of interpretation, understood as a multifunction that preserves and reflects logical consequence, capture a number of relevant transformations in the context of software design, reuse, and adaptation, difficult to deal with in classical approaches. Examples include data encapsulation and the decomposition of operations into atomic transactions. But if interpretations open such a new research avenue in program refinement, (conceptual) tools are needed to reason about them. In this line, the paper’s main contribution is a study of the correspondence between logical interpretations and morphisms of a particular kind of coalgebras. This opens way to the use of coalgebraic constructions, such as simulation and bisimulation, in the study of interpretations between (abstract) logics.Fundação para a Ciência e a Tecnologia (FCT
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