746 resultados para Bcl-X1


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The Brazilian Northeast is the most vulnerable region to climatic variability risks. For the Brazilian semi-arid is expected a reduction in the overall rates of precipitation and an increase in the number of dry days. These changes predicted by the IPCC (2007) will intensify the rainfall and droughts period that could promote the dominance of cyanobacteria, thus affecting the water quality of reservoirs, that are most used for water supply, in the semi-arid. The aim of this study was to evaluate the effects of increasing temperature combined with nutrient enrichment on the functional structure of the phytoplankton community of a mesotrophic reservoir in the semi-arid, in the worst case scenario of climate change predicted by the IPCC (2007). Two experiments were performed, one in a rainy season and another in the dry season. In the water sampled, nutrients (nitrate and orthophosphate) were added in different concentrations. The microcosms were submitted to two different temperatures, five-year average of air temperature in the reservoir (control) and 4°C above the control temperature (warming). The results of this study showed that warming and nutrient enrichment benefited mainly the functional groups of cyanobacteria. During the rainy season it was verified the increasing biomass of small functional groups of unicellular and opportunists algae such as F (colonial green algae with mucilage) and X1 (nanoplanktonic algae of eutrophic lake systems). It was also observed an increasing in total biomass, in the richness and diversity of the community. In the dry season experiment there was a greater contribution in the relative biomass of filamentous algae, with a replacement of the group S1 (non-filamentous cyanobacteria with heterocytes) for H1 (filamentous cyanobacteria with heterocytes) in nutrient- enriched treatments. Moreover, there was also loss in total biomass, species richness and diversity of the community. The effects of temperature and nutrients manipulation on phytoplankton community of reservoir Ministro João Alves provoked changes in species richness, the diversity of the community and its functional composition, being the dry period which showed the highest susceptibility to the increase in the contribution of potentially toxic cyanobacteria with heterocytes

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The present investigation includes a study of Leonhard Euler and the pentagonal numbers is his article Mirabilibus Proprietatibus Numerorum Pentagonalium - E524. After a brief review of the life and work of Euler, we analyze the mathematical concepts covered in that article as well as its historical context. For this purpose, we explain the concept of figurate numbers, showing its mode of generation, as well as its geometric and algebraic representations. Then, we present a brief history of the search for the Eulerian pentagonal number theorem, based on his correspondence on the subject with Daniel Bernoulli, Nikolaus Bernoulli, Christian Goldbach and Jean Le Rond d'Alembert. At first, Euler states the theorem, but admits that he doesn t know to prove it. Finally, in a letter to Goldbach in 1750, he presents a demonstration, which is published in E541, along with an alternative proof. The expansion of the concept of pentagonal number is then explained and justified by compare the geometric and algebraic representations of the new pentagonal numbers pentagonal numbers with those of traditional pentagonal numbers. Then we explain to the pentagonal number theorem, that is, the fact that the infinite product(1 x)(1 xx)(1 x3)(1 x4)(1 x5)(1 x6)(1 x7)... is equal to the infinite series 1 x1 x2+x5+x7 x12 x15+x22+x26 ..., where the exponents are given by the pentagonal numbers (expanded) and the sign is determined by whether as more or less as the exponent is pentagonal number (traditional or expanded). We also mention that Euler relates the pentagonal number theorem to other parts of mathematics, such as the concept of partitions, generating functions, the theory of infinite products and the sum of divisors. We end with an explanation of Euler s demonstration pentagonal number theorem

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Brazil follows the tendency of some countries to update and/or review their fundamental geodetic network. The adoption of geocentric referentials like SIRGAS 2000, the new official reference system of the Geodetic Brazilian System has been an advance. Changes in referential implies in coordinates changes on the network stations as well as the network geometry. To make use of analogical and digital products which are already known in the old referentials are necessary approaches to the coordinate conversion, which minimize the distortions between the used reference frames. This paper presents a distortion modeling approach between reference frames, based on distortion grid generation by using the Shepard's method. To analyze the approach some experiments were performed with the generation of a 1 degrees x1 degrees distortion grid to model the distortions between SAD 69 (1996) and SIRGAS (2000) frames. The results in the test stations were promising, with an average reduction of 50% in the RMS coordinates after the distortions modeling.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Paracoccidioides brasiliensis (Pb) yeast cells can enter mammalian cells and probably manipulate the host cell environment to favor their own growth and survival. We studied the uptake of strain Pb 18 into A549 lung and Vero epithelial cells, with an emphasis on the repercussions in the cytoskeleton and the apoptosis of host cells. Cytoskeleton components of the host cells, such as actin and tubulin, were involved in the P. brasiliensis invasion process. Cytochalasin D and colchicine treatment substantially reduced invasion, indicating the functional participation of microfilaments (MFs) and microtubules (MTs) in this mechanism. Cytokeratin could also play a role in the P. brasiliensis interaction with the host. Gp43 was recognized by anti-actin and anti-cytokeratin antibodies, but not by anti-tubulin. The apoptosis induced by this fungus in infected epithelial cells was demonstrated by various techniques: TUNEL, DNA fragmentation and Bak and Bcl-2 immunocytochemical expression. DNA fragmentation was observed in infected cells but not in uninfected ones, by both TUNEL and gel electrophoresis methods. Moreover, Bcl-2 and Bak did not show any differences until 24 h after infection of cells, suggesting a competitive mechanism that allows persistence of infection. Overexpression of Bak was observed after 48 h, indicating the loss of competition between death and survival signals. In conclusion, the mechanisms of invasion of host cells, persistence within them, and the subsequent induction of apoptosis of such cells may explain the efficient dissemination of P. brasiliensis. (C) 2004 Published by Elsevier SAS.

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

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

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

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In this work we studied the asymptotic unbiasedness, the strong and the uniform strong consistencies of a class of kernel estimators fn as an estimator of the density function f taking values on a k-dimensional sphere

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Vascular anomalies constitute a distinct group of lesions, but they may present similar clinical and histopatological characteristics, which can lead to diagnostic mistakes. This study aimed by histopathology and immunohistochemical expression of human glucose transporter protein (GLUT-1), correctly identify and classify oral vascular anomalies, besides analyzing the immunoexpression of markers proliferation and apoptosis (Ki-67 and Bcl-2). All cases diagnosed as "oral hemangiomas" belonging to the archives of the Service of Pathological Anatomy from the subject of Oral Pathology of the Department of Dentistry (DOD), of the Federal University of Rio Grande do Norte (UFRN) were reviewed, totalizing 77 cases. Immunohistochemical analysis for GLUT-1 showed that only 26 (33.8%) of the specimens were true infantile hemangiomas (IHs). The 51 (66.2%%) GLUT-1 negative specimens were then reclassified as pyogenic granulomas (PGs) and vascular malformations (VMs) from their histopathologic characteristics,totalizing 26 (33.8%) cases of IHs, 20 (26.0%) of PGs and 31 (40.2) cases of oral VMs. The cases analyzed by the marker Ki-67 showed different median IH (13,85), PG (33,70) and VM (4.55) with statistically significant differences between them (p <0.001). In relation to the protein Bcl-2, the groups also showed different median of the established scores IH (1.00), PG (1.50), VMs (0.0) demonstrating statistically significant differences between them (p<0,001). No statistically significant correlation between the indexes of positivity for Ki-67 and the scores of immunoexpression of Bcl-2 were observed in any group. Thus, we can conclude that it is necessary a careful and parameterized review of cases of vascular anomalies making use of auxiliary tools such as GLUT-1, since the histopathological findings alone, sometimes, are not sufficient to differentiate some anomalies. Furthermore, analysis of the expressions of markers involved in the levels of proliferation of lesions is important for a better understanding of its biological behavior aspect

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The aim of this study was to evaluate the changes caused by chronic diabetes in the rat ventral prostate and to establish a correlation between diabetes and the development of prostatic lesions. Male rats received alloxan (42 mg/kg b.w.) to induce diabetes. Ninety days after diabetes diagnosis, animals were sacrificed and the ventral prostate was removed and prepared for general and immunohistochemical analyses. The total area showing different types of lesions was estimated. Diabetes led to a decrease in the body and prostatic weights, as well as in testosterone levels. The prostate morphology and stereology showed high variation in the diabetic group. Some animals had light changes; the great majority had an intense epithelial atrophy; and other rats showed premalignant and malignant lesions in the prostate. Such epithelial atrophy was, in some samples, combined with chronic inflammation, similar to proliferative inflammatory atrophy (PIA). The diabetic group also presented high incidence of prostatitis, adenocarcinoma and prostatic intra-epithelial neoplasia (PIN). Samples with adenocarcinoma had poorly differentiated acini with high levels of cellular proliferation and nuclear atypia. These lesions exhibited an invasive feature showing Bcl-2-positive cells and interruptions in the basement membrane. An association of PIA, PIN and adenocarcinoma was detected in one sample. Reduced androgen levels have a synergic effect to insulin dysfunction promoting negative effects in the rat prostate. Diabetic individuals had a high incidence of prostatitis, and this inflammation could stimulate the incidence of other forms of prostatic pathology.

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Water scarcity is a reality for the inhabitants of the Brazilian semiarid region. The problem, in quantitative terms , is caused due to local climatic conditions due mostly to a water deficit. Qualitatively, results of multiple uses and resulting contamination by human activities. Eutrophication is presented as a threat to the sustainable use of water resources, in order to favor the predominance of dense populations of cyanobacteria, which can be potentially harmful to human health. The aim of this study is to understand the population dynamics of phytoplankton and cyanobacteria to assess water quality of reservoirs Santa Cruz do Apodi and Pau dos Ferros belonging to bacia Apodi Mossoró-RN . Water samples were collected monthly between October 2011 and May 2012 in reservoirs Santa Cruz do Apodi and Pau dos Ferros, in this latter , in Jan/12 we performed a diel profile . The abiotic variables obtained in the field and in the laboratory were: water temperature , dissolved oxygen , pH , turbidity , transparency , total nitrogen and total phosphorus . Phytoplankton samples were collected with a plankton net and bottle of Van dorn . Were performed : identification , quantification , calculation of biovolume , classification into functional groups and index calculation phytoplankton assembly ( Q ) , cyanotoxins were quantified by ELISA . Statistical analyzes supported the evaluation of the dynamics between biotic and abiotic factors. A questionnaire was conducted to examine the conceptions of the population, education professionals and students. The reservoir of Pau dos Ferros, shallow , turbid and eutrophic showed dominance of the functional group SN throughout the sample period . The phytoplankton biomass ranged from 20 to 70 mm ³ . L - 1, the lowest values coincided with the increase of the mixing zone and transparency, which contributed to the occurrence of a change in species composition phytoplankton . The application of the index Q proved relevant, the reservoir of Pau dos Ferros , depending on the species present , was classified ecologically as bad for almost the entire sample period . The reservoir Santa Cruz do Apodi showed low biomass ( 0.04 and 4.31 mm ³ . L - 1 ) and greater diversity in the phytoplankton composition . According to the index assembly (Q ), it showed moderate condition during most of the period influenced by different functional groups of typical meso- eutrophic environment (K S0, H1, C, F , J , E, D and N) . Associations of diatoms and green algae D and X1 succeeded populations of cyanobacteria in periods marked by greater instability in the system , caused by wind or rain. In summary , the occurrence of drought has a direct influence on the hydrological conditions of the reservoirs , in general, these events, reducing the reservoir level is directly related to decreased water quality and increased density of phytoplankton occurring predominance of cyanobacteria , the index Q reflected well to changes in phytoplankton composition , being a good indicator for biomonitoring of reservoirs in this study and survey of previous conceptions showed the need to work on environmental awareness for the preservation of water resources by conducting workshops for Environmental Education

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