120 resultados para Cluster Analysis. Information Theory. Entropy. Cross Information Potential. Complex Data


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Along with the growth of scientific production, the bibliometric studies have become essential, providing relevant information about any domain while identifying, highlighting and viewing the scientific knowledge constructed within a theme, subject or knowledge area. This article approaches the bibliometric studies under the light of metatheory and domain analysis within the knowledge organization in information science. domain analysis and metatheory are considered significant contribution to bibliometric studies when emphasizing the need for epistemological, sociological and historical analyzes, as well as other qualitative approaches, encouraging researchers to reflect on the whole composition of the research object, by means of different methodological, theoretical and epistemological approaches. This study aims at contributing to the discourse of the theoretical aspects of bibliometric studies by presenting considerations concerning Hjorland's domain analysis, as well as Ritzer's metatheoretical approach, featuring discussions on major theories of a study field, since these approaches together provide a more complete qualitative view upon an area, here, represented by the bibliometric studies.

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Ovigerous females of Ucides cordatus were collected at different mangrove areas in Iguape, SP, Brazil, and reared in the laboratory in order to describe each embryonic stage. Accounts of the biometry, internal morphology, and coloration of the eggs were taken. The embryonic development took 19 +/- 1d (27degreesC, 12:12 h) with eight well-defined stages. A salinity test on embryonic development was conducted, and a better result was obtained in a rearing at 15parts per thousand. Eggs are slightly ellipsoid through development and undergo an increase of 13.9% in diameter to 91.7% in volume. Cluster analysis revealed three different groups for diameter (Stages I-II, III-VI, and VII-VIII) and volume (Stages I-III, IV-V, and VI-VIII), supporting the classification of embryos into initial, intermediate, and final stages, which are currently used in studies on the reproductive biology of decapod crustaceans. In this species, the identification of the different embryonic stages can be achieved only if biometric data are combined with information on the internal morphology of embryos and coloration of the eggs.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Background: Leptospirosis is an important zoonotic disease associated with poor areas of urban settings of developing countries and early diagnosis and prompt treatment may prevent disease. Although rodents are reportedly considered the main reservoirs of leptospirosis, dogs may develop the disease, may become asymptomatic carriers and may be used as sentinels for disease epidemiology. The use of Geographical Information Systems (GIS) combined with spatial analysis techniques allows the mapping of the disease and the identification and assessment of health risk factors. Besides the use of GIS and spatial analysis, the technique of data mining, decision tree, can provide a great potential to find a pattern in the behavior of the variables that determine the occurrence of leptospirosis. The objective of the present study was to apply Geographical Information Systems and data prospection (decision tree) to evaluate the risk factors for canine leptospirosis in an area of Curitiba, PR.Materials, Methods & Results: The present study was performed on the Vila Pantanal, a urban poor community in the city of Curitiba. A total of 287 dog blood samples were randomly obtained house-by-house in a two-day sampling on January 2010. In addition, a questionnaire was applied to owners at the time of sampling. Geographical coordinates related to each household of tested dog were obtained using a Global Positioning System (GPS) for mapping the spatial distribution of reagent and non-reagent dogs to leptospirosis. For the decision tree, risk factors included results of microagglutination test (MAT) from the serum of dogs, previous disease on the household, contact with rats or other dogs, dog breed, outdoors access, feeding, trash around house or backyard, open sewer proximity and flooding. A total of 189 samples (about 2/3 of overall samples) were randomly selected for the training file and consequent decision rules. The remained 98 samples were used for the testing file. The seroprevalence showed a pattern of spatial distribution that involved all the Pantanal area, without agglomeration of reagent animals. In relation to data mining, from 189 samples used in decision tree, a total of 165 (87.3%) animal samples were correctly classified, generating a Kappa index of 0.413. A total of 154 out of 159 (96.8%) samples were considered non-reagent and were correctly classified and only 5/159 (3.2%) were wrongly identified. on the other hand, only 11 (36.7%) reagent samples were correctly classified, with 19 (63.3%) samples failing diagnosis.Discussion: The spatial distribution that involved all the Pantanal area showed that all the animals in the area are at risk of contamination by Leptospira spp. Although most samples had been classified correctly by the decision tree, a degree of difficulty of separability related to seropositive animals was observed, with only 36.7% of the samples classified correctly. This can occur due to the fact of seronegative animals number is superior to the number of seropositive ones, taking the differences in the pattern of variable behavior. The data mining helped to evaluate the most important risk factors for leptospirosis in an urban poor community of Curitiba. The variables selected by decision tree reflected the important factors about the existence of the disease (default of sewer, presence of rats and rubbish and dogs with free access to street). The analyses showed the multifactorial character of the epidemiology of canine leptospirosis.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In Brazil, sugarcane fields are often burned to facilitate manual harvesting, and this burning causes environmental pollution from the large amounts of soot released into the atmosphere. This material contains numerous organic compounds such as PAHs. In this study, the concentrations of PAHs in two particulate-matter fractions (PM2.5 and PM10) in the city of Araraquara (SE Brazil, with around 200,000 inhabitants and surrounded by sugarcane plantations) were determined during the sugarcane harvest (HV) and non-harvest (NHV) seasons in 2008 and 2009. The sampling strategy included four campaigns, with 60 samples in the NHV season and 220 samples in the HV season. The PM2.5 and PM10 fractions were collected using a dichotomous sampler (10 L min(-1), 24 h) with Teflon (TM) filters. The filter sets were extracted (ultrasonic bath with hexane/acetone (1:1 v/v)) and analyzed by HPLC/Fluorescence. The median concentration for total PAHs (PM2.5 in 2009) was 0.99 ng m(-3) (NHV) and 3.3 ng m(-3) (HV). In the HV season, the total concentration of carcinogenic PAHs (benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene) was 5 times higher than in the NHV season. B(a)P median concentrations were 0.017 ng m(-3) and 0.12 ng m(-3) for the NHV and HV seasons, respectively. The potential cancer risk associated with exposure through inhalation of these compounds was estimated based on the benzo[a]pyrene toxic equivalence (BaPeq), where the overall toxicity of a PAR mixture is defined by the concentration of each compound multiplied by its relative toxic equivalence factor (TEF). BaPeq median (2008 and 2009 years) ranged between 0.65 and 1.0 ng m(-3) and 1.2-1.4 ng m(-3) for the NHV and HV seasons, respectively. Considering that the maximum permissible BaPeq in ambient air is 1 ng m(-3), related to the increased carcinogenic risk, our data suggest that the level of human exposure to PAHs in cities surrounded by sugarcane crops where the burning process is used is cause for concern. (C) 2010 Published by Elsevier Ltd.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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We show that for the pion-nucleon theory the thermal bubble graph is analytic at the origin of the momentum-frequency space, although the internal propagators in the loop have the same mass. This means that, for this theory, the thermal effective potential is uniquely defined. We then examine how a slight modification of the interaction term results in a theory for which the thermal bubble graph displays the usual nonanalyticity at the origin and the thermal effective potential is not uniquely defined.

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This work is related with the proposition of a so-called regular or convex solver potential to be used in numerical simulations involving a certain class of constitutive elastic-damage models. All the mathematical aspects involved are based on convex analysis, which is employed aiming a consistent variational formulation of the potential and its conjugate one. It is shown that the constitutive relations for the class of damage models here considered can be derived from the solver potentials by means of sub-differentials sets. The optimality conditions of the resulting minimisation problem represent in particular a linear complementarity problem. Finally, a simple example is present in order to illustrate the possible integration errors that can be generated when finite step analysis is performed. (C) 2003 Elsevier Ltd. All rights reserved.

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The acquisition and update of Geographic Information System (GIS) data are typically carried out using aerial or satellite imagery. Since new roads are usually linked to georeferenced pre-existing road network, the extraction of pre-existing road segments may provide good hypotheses for the updating process. This paper addresses the problem of extracting georeferenced roads from images and formulating hypotheses for the presence of new road segments. Our approach proceeds in three steps. First, salient points are identified and measured along roads from a map or GIS database by an operator or an automatic tool. These salient points are then projected onto the image-space and errors inherent in this process are calculated. In the second step, the georeferenced roads are extracted from the image using a dynamic programming (DP) algorithm. The projected salient points and corresponding error estimates are used as input for this extraction process. Finally, the road center axes extracted in the previous step are analyzed to identify potential new segments attached to the extracted, pre-existing one. This analysis is performed using a combination of edge-based and correlation-based algorithms. In this paper we present our approach and early implementation results.

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Collagen makes up one third of the total protein in humans, being formed by the connection of three polypeptide chains arranged in a triple helix. This protein has fundamental importance in the formation of extracellular matrix of connective tissue. This study aimed to analyze the structural changes of collagen, which are resulting from inflammatory processes in oral mucosa, and to make the comparative analysis between the histopathology and the Raman spectra. The samples of tissues with inflammatory fibrous hyperplasia (IFH) and normal mucosa (NM) were evaluated by Raman Spectroscopy, hematoxylin-eosin and Massons trichrome stain. The histological analysis in both stains showed differences in collagen fibers, which was presented as thin fibers and arranged in parallel direction in NM and as collagen fibers are thick, mature and not organized, showing that these types of stain show morphological changes of collagen in IFH. The Raman Spectroscopy discriminate the groups of NM and IFH based on vibrational modes of proline, hydroxiproline and CH3, CH2. The histological stains only shows information from morphological data, and can be complemented by Raman spectra. This technique could demonstrate that inflammatory process caused some changes in collagen structure which is related to aminoacids such as proline and hidroxyproline. © 2011 SPIE-OSA.

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Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV