99 resultados para clusters of galaxies


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The structural characteristics of saturated silica sonogels were studied by means of small-angle x-ray scattering (SAXS) and thermogravimetric analysis (TG), after a long time of aging in saturated conditions. The sonogels were obtained by a sol-gel routine from ultrasound stimulated tetramethoxysilane (TMOS) hydrolysis carried out with the initial water/TMOS molar ratio (r) ranging from 2 to 10. The saturated sonogel structure can be described as composed by mass fractal-like aggregates (clusters) of primary silica particles, all imbibed in a liquid phase. The values of the mass fractal dimension (D) of the clusters was found all around 2.5, while the characteristic size of the clusters (ξ) was found generally increasing with r, going from approximately 2.3 nm (r = 2) to 4.5 nm (r = 10). The volume fraction of the clusters was estimated from the SAXS data. The results were compared to the values of weight loss fraction at the inflection point that has been found in the derivative of the TG curve, which should accounts for the instant in which the meniscus of the liquid phase penetrates into the clusters under a rapid evaporation process as in a TG test.

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Liver and lymph nodes injuries characterized by clusters of foamy macrophages, some of them containing birefringent crystals, were observed in cattle fed on Brachiaria brizantha hay. The cattle were from an experimental group poisoned with Senecio brasiliensis known to cause hepatic fibrosis and hepatocyte megalocytosis. One of the animals developed photosensitivity but the exact cause wasn't determined since both plants were fed. The foamy macrophages were present from the 30th d of feeding. Early appearance of these lesions may be particular to the animal specie used or due to the presence of both toxic plants.

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This case report describes a case of a mammary invasive pleomorphic lobular carcinoma in a female dog. Cytology revealed small cohesive clusters of cells and many scattered single large round cells with eccentric nuclei. Histologically, the neoplasm presented plasmacytoid cells with multiple, often bizarre nuclei and an invasive pattern with cells occasionally arranged in Indian files. Vascular invasion was consistently present. Tumour cells also revealed loss of E-cadherin immunoexpression and positive immunoreactivity for HER2/c-erbB2, oestrogen receptor alpha, cytokeratin 19, and Ki67 (52 %), and the tumour was characterised as a mammary invasive pleomorphic lobular carcinoma. This is an interesting case since this is a rare condition that is not widely recognised in dogs. © 2012 Springer-Verlag London Limited.

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Background: Members of the Anostomidae family provide an interesting model system for the study of the influence of repetitive elements on genome composition, mainly because they possess numerous heterochromatic segments and a peculiar system of female heterogamety that is restricted to a few species of the Leporinus genus. The aim of this study was to isolate and identify important new repetitive DNA elements in Anostomidae through restriction enzyme digestion, followed by cloning, characterisation and chromosome mapping of this fragment. To identify repetitive elements in other Leporinus species and expand on studies of repetitive elements in Anostomidae, hybridisation experiments were also performed using previously described probes of LeSpeI repetitive elements. Results: The 628-base pair (bp) LeSpeII fragment was hybridised to metaphase cells of L. elongatus individuals as well as those of L. macrocephalus, L. obtusidens, L. striatus, L. lacustris, L. friderici, Schizodon borellii and S. isognathus. In L. elongatus, both male and female cells contained small clusters of LeSpeII repetitive elements dispersed on all of the chromosomes, with enrichment near most of the terminal portions of the chromosomes. In the female sex chromosomes of L. elongatus (Z2,Z2/W1W 2), however, this repeated element was absent. In the remaining species, a dispersed pattern of hybridisation was observed on all chromosomes irrespective of whether or not they were sex chromosomes. The repetitive element LeSpeI produced positive hybridisations signals only in L. elongatus, L. macrocephalus and L. obtusidens, i.e., species with differentiated sex chromosomes. In the remaining species, the LeSpeI element did not produce hybridisation signals. Conclusions: Results are discussed in terms of the effects of repetitive sequences on the differentiation of the Anostomidae genome, especially with respect to sex chromosome evolution. LeSpeII showed hybridisation patterns typical of Long Interspersed Elements (LINEs). The differential distribution of this element may be linked to sex chromosome differentiation in L. elongatus species. The relationship between sex chromosome specificity and the LeSpeI element is confirmed in the species L. elongatus, L. macrocephalus and L. obtusidens. © 2012 da Silva et al.; licensee BioMed Central Ltd.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The position of 125 countries is studied on the basis of a collection of 26 basic, health, economic and educational indicators. Multivariate statistical methods were used, including Cluster Analysis, Principal Component Analysis and Multivariate Analysis of Variance. The most discriminating variables were life expectancy the child mortality rate, the mortality rate of children of less than five years of age, the birth and fertility rates and the high-school female matriculation rate. The first principal component was interpreted as a measure of the living standard which made it possible to place the countries in order. Five clusters of countries are suggested.

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Materials with high photoluminescence (PL) intensity can potentially be used in optical and electronic devices. Although the PL properties of bismuth(III) oxide with a monoclinic crystal structure (α-Bi2O3) have been explored in the past few years, methods of increasing PL emission intensity and information relating PL emission to structural defects are scarce. This research evaluated the effect of a pressure-assisted heat treatment (PAHT) on the PL properties of α-Bi2O3 with a needlelike morphology, which was synthesized via a microwave-assisted hydrothermal (MAH) method. PAHT caused an angular increase between the [BiO6]-[BiO6] clusters of α-Bi2O3, resulting in a significant increase in the PL emission intensity. The Raman and XPS spectra also showed that the α-Bi2O3 PL emissions in the low-energy region (below ∼2.1 eV) are attributed to oxygen vacancies that form defect donor states. The experimental results are in good agreement with first-principles total-energy calculations that were carried out within periodic density functional theory (DFT).

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

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One of needs of modern agriculture is the prediction of spatial variability of soil properties at more detailed scales for sustainable management and optimization of management practices. The mathematical model associated with knowledge of variability of soil attributes and mapping of relief forms has helped in agricultural planning. In this regard the aim of this study was to characterize the spatial variability of physical and chemical properties of Oxisols and Ultisols using numerical classification and the digital elevation model. Two distinct landforms: convex for the Oxisol (158 ha) and linear for the Ultisol (172 ha). 53 samples from the Oxisol and 57 samples from the Ultisol were taken. Multivariate analysis of clusters of attributes studied from their euclidean distances was performed. This analysis by dendograms along with digital elevation models for different soils characterized was more homogeneous in Ultisol groups, and less homogeneous for the Oxisol in convex landform. These quantitative methods showed that the landforms conditioned the spatial pattern of soil attributes.

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Este trabalho teve por objetivo realizar um levantamento em 40 vinhedos de 'Niagara Rosada' nos municípios de Jundiaí e Louveira-SP, sendo metade sobre o porta-enxerto 'Ripária do Traviú' e outra sobre o 'IAC 766'. Determinaram-se, em cada vinhedo, a produtividade, a duração do ciclo, o número de cachos e de ramos produtivos por planta, as características físicas dos cachos e bagas, e o acúmulo de nutrientes pelos cachos. Avaliaram-se nos cachos amostrados a massa da matéria fresca, o comprimento e a largura dos cachos e baga, e diâmetro do pedicelo. Os cachos de cada vinhedo amostrado foram secos em estufa e posteriormente submetidos à análise química para determinar os teores de macro e micronutrientes, visando a estimar o acúmulo de nutrientes por tonelada de uva. Constatou-se um comportamento semelhante entre os porta-enxertos para os dados de produtividade, duração do ciclo, número de cachos e ramos produtivos, sendo de, respectivamente, 11.100kg ha-1, 134 dias, 13 cachos e 9 ramos produtivos. Quanto às características físicas, os valores médios da massa da matéria fresca, comprimento e largura dos cachos foram de, respectivamente, 209g, 12 e 6,8cm; massa da matéria fresca, comprimento e largura das bagas, e diâmetro do pedicelo de, respectivamente, 4,3g; 19,9; 18,2 e 3,2mm. Quanto ao acúmulo de nutrientes, concluiu-se que a cultivar Niagara Rosada enxertada sobre 'Ripária do Traviú' apresentou maior acúmulo de P, Fe e Zn, enquanto sobre o porta-enxerto 'IAC 766' houve maior acúmulo de Mn. em ambos os porta-enxertos, a 'Niagara Rosada' apresentou a seguinte escala de acúmulo de nutrientes em ordem decrescente: K>N>P>Ca>S>Mg>B>Fe>Mn>Cu>Zn.

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OBJETIVO: Avaliar parâmetros bioquímicos e fisiológicos em adolescentes do sexo feminino com sobrepeso/obesidade ou com peso corporal normal e avaliar se fatores de risco cardiovascular, postulados como componentes da síndrome metabólica, já estão presentes nessa faixa etária. MÉTODOS: Estudo transversal, tendo-se comparado a totalidade de meninas com idades entre 12 e 18 anos de um colégio de Ribeirão Preto, divididas em dois grupos: sobrepeso/obesidade (n=30) e controle (n=39). de cada menina, foram avaliados parâmetros antropométricos (peso, estatura, dobras cutâneas, circunferências do abdome e do quadril) e bioquímicos (glicose, insulina, lipidograma, ureia, creatinina, fibrinogênio, PAI-1, ferritina, sódio e microalbuminúria). RESULTADOS: As adolescentes com sobrepeso/obesidade apresentaram níveis maiores de pressão arterial, glicose, triglicérides, ácido úrico, PAI-1, fibrinogênio e insulina e níveis menores de colesterol-HDL em relação ao grupo controle. A análise de alterações e formação de clusters de fatores de risco demonstrou que 76,7% das adolescentes do grupo sobrepeso apresentaram dois ou mais fatores de risco relacionados à síndrome metabólica, enquanto 79,5% das adolescentes do grupo controle apresentaram nenhuma ou apenas uma alteração. Os parâmetros microalbuminúria e ferritina sérica não apresentaram alterações e diferenças entre os grupos. CONCLUSÕES: Adolescentes do sexo feminino com sobrepeso/obesidade já apresentam hipertensão, dislipidemias, disfibrinólise, hiperinsulinemia e clusters de fatores de risco cardiovascular.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)