346 resultados para Compósitos com fibras naturais
Resumo:
A Multi-locus mixed mating model and correlated mating model were used to analyze the mating system of four natural populations of Peltophorum dubium (Sprengel) Taubert from Western Sao Paulo State, Brazil. Open pollinated seeds were collected from 19 to 33 seed-trees per population and evaluated by allozyme electrophoresis analysis. Significant differences between pollen and ovule gene frequencies were detected in more than 50% of loci in each population, indicating deviations from random mating, probably due to correlated mating, self-fertilizations and mating among relatives. The comparison the fixation index estimated from seed trees ((F) over cap (m), ranged from 0.009 to 0.285) with their progenies ((F) over cap (p), ranged from 0.127 to 0.364) suggested selection against inbreeding between offspring of adult stages. The estimates of multi-locus outcrossing rate (t(m)) ranged from 0.557 to 0.924, indicating that the species has a mixed-mating system. Differences between multi-locus and single-locus outcrossing rate (t(m)-t(s))was positive and significantly different from zero for all populations, with values ranging from 0.092 to 0.111, suggesting mating among relatives within the populations, probably due to the presence of intra-population spatial genetic structure. The mean coefficient of co-ancestry (Theta) within progenies ranged from 0.147 to 0.251; confirming that the progenies are compounded by mixtures of different kinds of relatedness. The results are discussed from the view of genetic improvement and conservation of the species.
Resumo:
Pós-graduação em Odontologia - FOAR
Resumo:
Pós-graduação em História - FCLAS
Resumo:
Using ELISA technique, natural antibodies against self and non self antigens were determined in 80 patients chronically intected by T. cruzi and 40 individuals suffering from a deep mycosis frequentely found in Latin Amarica (Paracoccidioidomycosis - PCM). Two forms of PCM were investigated: adult forms and juvenil type of disease. Eighty percent (80%) of the former group had significantly elevated anti-laminin antibody levels (M=4.7,SD±1.8) compared with healthy controls and different specificities of antibody were associated with anti-laminin in pathological sera. A notable binding to cytoskeletal proteins was observed, specially with band 3 and their peptides derivates, such as 62 kDa peptide. By means of Protein A chromatography we were able to show that natural anti-Gal antibodies may be bound by their Fab region to other immunoglobulins and/or to Protein A by alternative sites of binding. The finding of lgG anti-Gal antibodies in circulating immune complexes isolated from chagasic sera supported the first alternative. However, it is possible that some of lgG anti-Gal antibodies, belong to VH111 subgroup of immunoglobulins, that bind directly to Protein A. Among the 40 sera from PCM examined, the majority was considered as not exhibiting a signilicantly higher binding than normal sera to antigens tested. However thirty percent (30%) of the chronic patients had an increased levels of natural antibodies at least for one specificity such as actyn, myosin and Gala1,3Gal epitopes. ln juvenil type of PCM the mean value found for actyn was also increased 2,42 (range 1,0 to 5,3). Utilizing the polyethylene glicol precipitation the presence of circulating immune complexes was investigated in PCM sera. Specific antibodies for soluble antigens from P. brasiliensis and natural antibodies against myoglobin, myosin and Gala1,3 Gal epitopes were characterized
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Pós-graduação em Ciência e Tecnologia de Materiais - FC
Resumo:
Pós-graduação em Agronomia (Energia na Agricultura) - FCA
Resumo:
Pós-graduação em Ciências Odontológicas - FOAR
Resumo:
Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV
Resumo:
As formigas cortadeiras, pertencentes aos gêneros Atta e Acromyrmex, possuem esse nome pelo hábito que têm de cortar as folhas das plantas. Por este motivo, elas causam danos econômicos, principalmente em áreas de cultura agrícola. Para realizar o controle dessas pragas, existem inúmeros métodos; porém, os únicos que apresentam resultados satisfatórios são os que utilizam inseticidas tradicionais. O controle químico pode gerar efeitos maléficos ao ambiente, à fauna e à população humana. É por isso que há uma grande procura por métodos alternativos, utilizando produtos que tenham grande especificidade e sejam passíveis de rápida degradação, sendo, portanto, menos danosos ao ambiente. Uma destas alternativas é a utilização de produtos naturais presentes nos vegetais superiores, que podem constituir novas fontes de material com ação tóxica para estes insetos praga. Este trabalho teve por objetivo avaliar a toxicidade das plantas Magonia pubescens e Duguetia lanceolata para operárias de Atta sexdens rubropilosa. Para os testes, as formigas foram divididas em lotes de 50 operárias, distribuídas em 5 placas para cada tratamento e mantidas em B.O.D. durante os 25 dias do experimento. Nos bioensaios de ingestão, os extratos provenientes das plantas foram incorporados em dieta artificial e testados durante 25 dias. No bioensaio tópico, as substâncias eram colocadas no pronoto das formigas e era oferecida dieta pura em todos os dias do experimento. Após os testes, os dados foram transferidos para o software Prisma 3.0, para a confecção de curvas de sobrevivência e para a realização das análises estatísticas. Apesar de Magonia pubescens apresentar um bom resultado, não foi possível continuar com os testes, pois a alta polaridade dos extratos impossibilitava a separação das substâncias... (Resumo completo, clicar acesso eletrônico abaixo)
Resumo:
The region of the biome Cerrado is under threat due to the replacement of their native areas for expansion of agriculture and livestock. This occupation is responsible for the loss of about 50% of two million square kilometers of original native savannah. The land use, without control or zoning, has caused serious damage to natural resources of this biome, considered as an international hotspot area. As a result, some problems caused by ecological imbalances already topping the urban and rural environments, such as species extinction, water scarcity and desertification. Any occupation in this biome should be evaluated with caution, because this region, besides being considered one of the most productive of Brazil, is also rich in biodiversity and water resources. The understanding of the importance of the Cerrado biome and its remaining areas, allows the preparation of detailed studies of environmental valuation, which is essential for the development of conservation policies, avoiding even greater environmental impacts. To meet the growing demand for food, you can increase productivity through agroforestry, for example, and to preserve the remaining areas, you can create new protected areas and tailor existing units
Resumo:
In recent years the aeronautic industries has increased investment in areas of technological research aiming at materials that offer better performance, safety, weight reduction and fuel consumption. For this reason the most studied materials are polymeric materials, due to their higher mechanical strength and higher stiffness. This work evaluated characteristics of two composite laminates produced from the same process, but they differed only in regions where the resin was injected and the vacuum position. The composite laminates were SC-79 resin reinforced with glass fiber fabric (plain weave) processed via VARTM. For this reason the material was subjected to mechanical tests such as: tensile, and fatigue following standards ASTM D 3039 and ASTM D 3479, respectively. The latter was observed the S-N curve. It was performed the ultrassonic C-scan analysis to check impregnation of the fiber. Considering that the process was the same for the two laminates, with small variations in the injection and in vacum ports, it was expected to find similar characteristics
Resumo:
The urbanization process in the Brazilian cities is directly linked to its main economic activities, and causes several impacts on the natural resources. It can be seen at the city of Ilhabela, an archipelago located at the north coast of the state of São Paulo, that still has a great area of preserved Atlantic Rainforest, and where today the tourism is the main economic activity. With this in sight, this paper aimed to make a prospect of the current situation of the city, looking at the main aspects of its economic and urban development and the environmental impacts related to them. Among the aspects studied, are the irregular occupations at preservation areas on the island: the pressure on the sea ecosystems by the fishing and the boat circulation, and at the beaches by the tourists flow. Were also observed the characteristics of the city’s urban infrastructure, such as the water supply, sewer and road networks and the waste collecting. Finally, it was analyzed the way that the government acts over the preservation of the island’s natural resources, by the Municipality and the Ilhabela State Park, so that the acting of these two agents could be compared