277 research outputs found
Trabalhando a Matemática e a Geografia através do tema Sustentabilidade
O presente artigo trata sobre o desenvolvimento de duas maquetes, construídas por uma turma de nono ano, que foi dividida em dois grupos para trabalhar com o tema sustentabilidade. Um grupo construiu uma casa sustentável e o outro uma casa com consumo elevado de energia. O grupo da casa consumista desenvolveu um circuito para gerar energia e o outro uma casa com hábitos sustentáveis, visando à preservação dos recursos naturais. Para construir as casas utilizaram-se placas de fibra de madeira de média densidade (MDF – Medium-Density Fiberboard). Os alunos tiveram que medir portas e janelas reais e utilizar as devidas proporções para utilização do MDF. O Teorema de Pitágoras foi usado para encontrar as medidas das janelas, portas, molduras, entre outros. Para a construção da maquete, foi desenvolvida uma planta com as medições reais, desenvolvendo o estudo de Escala
Adubação nitrogenada em videiras jovens e em fase produtiva: recuperação e distribuição na planta do nitrogênio adicionado no solo.
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Comparison of two techniques for assessing pancreatic islet viability : flow cytometry and fluorescein diacetate/propidium iodide staining
Introduction: The success of islet transplantation for patients with unstable type 1 diabetes mellitus depends, in part, on the number of isolated islets and their quality, which is assessed by functional and viability tests. The test currently employed to evaluate islet viability, used by the Collaborative Islet Transplant Registry to release products for transplantation, is fluorescein diacetate/propidium iodide (FDA/PI) staining. However, the efficacy of this method relies on researcher experience; in this context, a quantitative method may be useful. The aim of this study was to compare islet viability as assessed by flow cytometry and the FDA/PI assay. Methods: Viability was analyzed in islets isolated from 10 male Wistar rats. Upon FDA/PI staining, 50 islets from each animal were analyzed under fluorescence microscopy by two well-trained researchers. For flow cytometry, islets were dispersed and 100 000 single cells were incubated with the 7-amino-actinomycin D (7AAD) fluorophore (dyes necrotic and late apoptotic cells) and the Annexin V-APC antibody (marks early apoptotic cells). Results: A moderate correlation was found between techniques (r = 0.6; p = 0.047). The mean islet viability measured by flow cytometry was higher than that estimated using FDA/PI staining (95.5 ± 1.4% vs 89.5 ± 5.0%; p = 0.002). Conclusions: Although flow cytometry is more expensive and time-consuming than FDA/PI staining, it is a quantitative technique with greater reproducibility that is less subject to inter-observer variability than FDA/PI. Therefore, flow cytometry appears to be the technique of choice when aiming for a more precise determination of islet viability
Cobre em solos cultivados com a videira na Serra Gaúcha do Rio Grande do Sul.
O presente trabalho objetivou determinar as formas de cobre e a cinética de dessorção em solos cultivados com a videira e submetidos a sucessivas aplicações de fungicidas cúpricos.bitstream/CNPUV/10103/1/cot086.pd
Mineralogical changes caused by grape production in a regosol from subtropical Brazilian climate.
Purpose Inadequate soil use and management practices promote commonly negative impacts on the soil constituents and their properties, with consequences to ecosystems. As the soil mineralogy can be permanently altered due to soil use, this approach can be used as a tool to monitor the anthropogenic pressure. The objective of the present study was to assess the mineralogical alterations of a Brazilian regosol used for grape production for 40 years in comparison with a soil under natural vegetation (forest), aiming to discuss anthropogenic pressure on soils. Material and methods Soil samples were collected at depths of 0?0.20 and 0.20?0.40 m from vineyard production and natural vegetation sites. Physical and chemical parameters were analysed by classic approaches. Mineralogical analyses were carried out on <2 mm, silt and clay fractions. Clay minerals were estimated by the relative percentage of peak surface area of the X-ray patterns. Results and discussion Grape production reduced the organic matter content by 28% and the clay content by 23% resulting in a decreasing cation exchange capacity. A similar clay fraction was observed in both soils, containing kaolinite, illite/mica and vermiculite with hydroxy-Al polymers interlayered. Neither gibbsite nor chlorite was found. However, in the soil under native vegetation, the proportion of illite (79 %) was higher than vermiculite (21 %). Whereas, in the soil used for grape production during 40 years, the formation of vermiculite was promoted. Conclusions Grape production alters the proportions of soil constituents of the regosol, reducing clay fraction and organic matter contents, as well as promoting changes in the soil clay minerals with the formation of vermiculite to the detriment of illite, which suggests weathering acceleration and susceptibility to anthropogenic pressure. Recommendations and perspectives Ecosystems in tropical and subtropical climates can be more easily and permanently altered due to anthropogenic pressure, mainly as a consequence of a great magnitude of phenomena such as temperature amplitude and rainfall that occurs in these regions. This is more worrying when soils are located on steep grades with a high anthropogenic pressure, like regosols in Southern Brazil. Thus, this study suggests that changes in soil mineralogy can be used as an important tool to assess anthropogenic pressure in ecosystems and that soil quality maintenance should be a priority in sensible landscapes to maintain the ecosystem quality
Recovery and distribution of supplied nitrogen to young grapevines
O objetivo deste trabalho foi estimar a recuperação e a distribuição do N fornecido a videiras jovens. O experimento foi realizado em casa de vegetação na Embrapa Uva e Vinho, Bento Gonçalves, RS. Foram utilizadas videiras da cultivar Riesling Itálico e Chardonnay, enxertadas no porta-enxerto 101-14 Mgt. Foi cultivada uma planta por vaso contendo 3,5 kg de um Neossolo Litólico. A solução de sulfato de amônio com 2% de átomos 15N, na dose de 185,60 mg de N foi aplicada na superfície do solo depois do transplante das videiras. As plantas foram coletadas em seis épocas, e separadas em folhas, porta-enxerto + enxerto, raízes grossas e finas. Todas as partes das videiras foram secadas em estufa, para determinação da produção de matéria seca e análise do N total e 15N. A maior recuperação do N do fertilizante pelas videiras jovens ocorreu em épocas próximas ao fornecimento do N. A maior quantidade de N acumulado nas videiras derivou-se de formas diferentes daquelas do N fornecido. As folhas e raízes foram o maior compartimento de N total e N derivado do fertilizante.The objective of this work was to estimate the recovery and the distribution of N supplied to young grapevines. The experiment was carried out in greenhouse at Embrapa Uva e Vinho, Bento Gonçalves, RS, Southern Brazil. Cultivars used were Riesling Itálico and Chardonnay grafted on rootstock 101-14 Mgt. One plant was cultivated in each vase containing 3.5 kg of Udorthent soil. The solution of ammonium sulphate with 2% atoms 15N, at the rate of 185.60 mg N, was applied on the soil surface after the transplantation of the grapevines. Plants were collected six times, during vegetative growth, and fractionated in leaves, rootstock + scion, thick roots and fine roots, and then oven-dried, weighted, and analyzed for total N and 15N contents. The largest N recovery of the fertilizer for the young grapevines ocurred in times near to the N supplying. The largest amount of N accumulated in the grapevines was derived from different forms of the N supplied. Leaves and roots were the largest compartment of total N and N fertilizer
VIAGEM PELO CÉU: ASTRONOMIA PROMOVENDO O SABER CIENTÍFICO NA EDUCAÇÃO INFANTIL E NAS SÉRIE INICIAIS DO ENSINO FUNDAMENTAL
Avaliação da expressão gênica de UCP1 em indivíduos com diferentes graus de obesidade e da sua correlação com os níveis plasmáticos de irisina
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