218 resultados para erosion features
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Pós-graduação em Geografia - FCT
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Since soil erosion is currently a worldwide threat, its control has become a necessity. The performance and effectiveness of synthetic organic polymers such polyacrylamide (PAM), have been intensively studied, especially for erosion control in temperate climate conditions. In tropical regions, however, where climatic conditions are usually severe, very little research has been conducted. The Brazilian region is a good example, where few papers on this subject exist. In addition to the severe climatic conditions, careless land use has been prevalent for many years. The use of PAM for erosion control in Brazilian soils may be a good option to minimize the impacts of the soil degradation process, but more research is required to optimize its application.
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Research on the micro-structural characterization of metal-matrix composites uses X-ray computed tomography to collect information about the interior features of the samples, in order to elucidate their exhibited properties. The tomographic raw data needs several steps of computational processing in order to eliminate noise and interference. Our experience with a program (Tritom) that handles these questions has shown that in some cases the processing steps take a very long time and that it is not easy for a Materials Science specialist to interact with Tritom in order to define the most adequate parameter values and the proper sequence of the available processing steps. For easing the use of Tritom, a system was built which addresses the aspects described before and that is based on the OpenDX visualization system. OpenDX visualization facilities constitute a great benefit to Tritom. The visual programming environment of OpenDX allows an easy definition of a sequence of processing steps thus fulfilling the requirement of an easy use by non-specialists on Computer Science. Also the possibility of incorporating external modules in a visual OpenDX program allows the researchers to tackle the aspect of reducing the long execution time of some processing steps. The longer processing steps of Tritom have been parallelized in two different types of hardware architectures (message-passing and shared-memory); the corresponding parallel programs can be easily incorporated in a sequence of processing steps defined in an OpenDX program. The benefits of our system are illustrated through an example where the tool is applied in the study of the sensitivity to crushing – and the implications thereof – of the reinforcements used in a functionally graded syntactic metallic foam.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Background: The number of Escherichia coli in the gut of Crohn's disease (CD) patients is higher than that of normal subjects, but the virulence potential of these bacteria is not fully known. Previous studies have shown that these E. coli are closely related to extraintestinal pathogenic categories (ExPEC), are able to invade epithelial cells, and usually do not produce exotoxins. We report here the detection, in a CD patient, of an E. coli which belongs to a classical enteropathogenic (EPEC) serotype and displays virulence markers of enteroinvasive (EIEC), enteroaggregative (EAEC) and enterohemorrhagic (EHEC) pathotypes. Methods: The E. coli strain was isolated, in 2009, by classical bacteriological procedures from a 56 year old woman who underwent ileo-terminal resection 1 year before, due to intestinal obstruction. The bacterial characterization was carried out by in vitro adhesion and invasion assays to cultured epithelial cells and macrophages and screening by PCR to identify virulence genetic markers of diarrheogenic E. coli (DEC) and to detect one of the gene combinations which define the phylogroups of the E. coli reference (EcoR) collection. The strain was also tested for the ability to produce biofilm and shiga cytotoxins and had its whole genome sequenced by Ion Torrent Sequencing Technology. Results: The studied strain, which was detected both in ileum biopsies and the stools of the patient, displayed the aggregative adherence (AA) phenotype to Hep-2 cells and an ability to enter Caco-2 cells 3x as high as that of EIEC reference strain and 89% of that of the prototype AIEC LF82 strain. Although it could invade cultured macrophages, the strain was unable to replicate inside these cells. PCR screening revealed the presence of eae, aggR and stx1. Tests with bacterial culture supernatants in Vero cells demonstrating cytotoxicity suggested the production of Stx1. In addition, the strain revealed to be a strong biofilm producer, belonged to the B2 EcoR phylogroup, to the O126:H27 serogroup and to the multilocus sequencing type (MLST) ST3057. The 2 later features were deduced from the whole genome sequence of the strain. Conclusions: The characterization of this E. coli isolate from a CD patient revealed a combination of virulence markers of distinct DEC pathotypes, namely eae and stx1 of EHEC, AA, aggR and biofilm formation of EAEC, and invasiveness of EIEC. These features along with its serotype and phylogroup identity seem to suggest a potential to be involved in CD, an observation which should be tested with additional studies.
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This study evaluated the genetic erosion risk factors and the strategic points for the conservation of Lychnophora ericoides population in “Paraíso Perdido” farm, Serra da Canastra (20° 37’ 54” S; 46° 19’ 37” W; 833 m height) in São João Batista do Glória City, Minas Gerais State, Brazil. The number of young and adult plants, the soil and the phenology were evaluated in two sample areas of 125 m2. Information about the species utilization was obtained with local informants. Data on the region were obtained through literature review, in loco evaluation, GPS and geo-referenced map. In addition, local use of the plant for mixtures of drug was evaluated. According to the results obtained, the soil of the population is lithic with a weathered portion of frank-sandy texture, very acidic and dystrophic. The population density is 0.16 individuals/m2, 0.078 young/adult plant. The predominant phenophase was fruiting (100% plants) followed by flowering (21.62% plants). The local community uses the leaves of the plant in the form of hydroalcoholic extracts, as anti-inflammatory. Based on the evaluated parameters, the population is at 73% risk of genetic erosion. The detected key points were the development of activities including the participation of the local community for habitat protection as well as germplasm collection, seedlings production and reintroduction, together with environmental education, supervision, and reduction in the propensity for fire.
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Pós-graduação em Geociências e Meio Ambiente - IGCE