901 resultados para partial numerical multiplier


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Publicationes Mathematicae Debrecen

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Outbred male albino mice normal or infected with 30 cercariae of Schistosoma mansoni (LE strain) were submitted to 65% hepatectomy during the acute (70 days) and chronic phase (160 days) phases of the disease. A group of the infected animals was treated with 400 mg/kg of oxamniquine during the acute phase before hepatectomy. Non-infected, infected and treated but not hepatectomized animals were kept as controls. Hepatic regeneration was evaluated by incorporation of tritiated thymidine, intraperitoneally injected into non-hepatectomized and hepatectomized animals, 24 hours after surgery. The results showed that removal of 65% of the hepatic parenchyma, during the acute phase, led to a statistically significant increase of thymidine incorporation, when compared with the uninfected hepatectomized controls. This phenomenon was not observed at the chronic phase. Treatment with oxamniquine administered during the acute phase led to a decrease in thymidine incorporation rate 160 days after infection (90 days after treatment) and 24 hours after hepatectomy. The data suggest that infection with S. mansoni represents a considerable stimulus for the regenerative capacity of the liver during the acute, but not the chronic phase of disease.

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Antigenic preparations (saline, methylic, metabolic and exoantigens) of four agents of chromoblastomycosis, Fonsecaea pedrosoi, Phialophora verrucosa, Cladophialophora (Cladosporium) carrionii and Rhinocladiella aquaspersa were obtained. Partial chemical characterization of these antigenic preparations was obtained by determination of the levels of total lipids, protein, and carbohydrates, and identification of the main sterols and carbohydrates. Methylic antigens presented the highest lipid contents, whereas metabolic antigens showed the highest carbohydrate content. Total lipid, protein, and carbohydrate levels were in the range of 2.33 to 2.00mg/ml, 0.04 to 0.02 mg/ml and 0.10 to 0.02 mg/ml, respectively, in the methylic antigens and in the range of 0.53 to 0.18mg/ml, 0.44 to 0.26mg/ml, and 1.82 to 1.02 mg/ml, respectively, in saline antigens. Total lipid, protein, and carbohydrate contents were in the range of 0.55 to 0.20mg/ml, 0.69 to 0.57mg/ml and 10.73 to 5.93mg/ml, respectively, in the metabolic antigens, and in the range of 0.55 to 0.15mg/ml, 0.62 to 0.20mg/ml and 3.55 to 0.42mg/ml, respectively, in the exoantigens. Phospholipids were not detected in the preparations. Saline and metabolic antigens and exoantigens presented hexose and the methylic antigen revealed additional pentose units in their composition. The UV light absorption spectra of the sterols revealed squalene and an ergosterol fraction in the antigens. The characterization of these antigenic preparations may be useful for serological evaluation of patients of chromoblastomycosis.

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Esta dissertação descreve o desenvolvimento e avaliação de um procedimento de \Numerical Site Calibration" (NSC) para um Parque Eólico, situado a sul de Portugal, usando Dinâmica de Fluídos Computacional (CFD). O NSC encontra-se baseado no \Site Calibration" (SC), sendo este um método de medição padronizado pela Comissão Electrónica Internacional através da norma IEC 61400. Este método tem a finalidade de quantificar e reduzir os efeitos provocados pelo terreno e por possíveis obstáculos, na medição do desempenho energético das turbinas eólicas. Assim, no SC são realizadas medições em dois pontos, no mastro referência e no local da turbina (mastro temporário). No entanto, em Parques Eólicos já construídos, este método não é aplicável visto ser necessária a instalação de um mastro de medição no local da turbina e, por conseguinte, o procedimento adequado para estas circunstâncias é o NSC. O desenvolvimento deste método é feito por um código CFD, desenvolvido por uma equipa de investigação do Instituto Superior de Engenharia do Porto, designado de WINDIETM, usado extensivamente pela empresa Megajoule Inovação, Lda em aplicações de energia eólica em todo mundo. Este código é uma ferramenta para simulação de escoamentos tridimensionais em terrenos complexos. As simulações do escoamento são realizadas no regime transiente utilizando as equações de Navier-Stokes médias de Reynolds com aproximação de Bussinesq e o modelo de turbulência TKE 1.5. As condições fronteira são provenientes dos resultados de uma simulação realizada com Weather Research and Forecasting, WRF. Estas simulações dividem-se em dois grupos, um dos conjuntos de simulações utiliza o esquema convectivo Upwind e o outro utiliza o esquema convectivo de 4aordem. A análise deste método é realizada a partir da comparação dos dados obtidos nas simulações realizadas no código WINDIETM e a coleta de dados medidos durante o processo SC. Em suma, conclui-se que o WINDIETM e as suas configurações reproduzem bons resultados de calibração, ja que produzem erros globais na ordem de dois pontos percentuais em relação ao SC realizado para o mesmo local em estudo.

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The aim of this research was to evaluate the protein polymorphism degree among seventy-five C. albicans strains from healthy children oral cavities of five socioeconomic categories from eight schools (private and public) in Piracicaba city, São Paulo State, in order to identify C. albicans subspecies and their similarities in infantile population groups and to establish their possible dissemination route. Cell cultures were grown in YEPD medium, collected by centrifugation, and washed with cold saline solution. The whole-cell proteins were extracted by cell disruption, using glass beads and submitted to SDS-PAGE technique. After electrophoresis, the protein bands were stained with Coomassie-blue and analyzed by statistics package NTSYS-pc version 1.70 software. Similarity matrix and dendrogram were generated by using the Dice similarity coefficient and UPGMA algorithm, respectively, which made it possible to evaluate the similarity or intra-specific polymorphism degrees, based on whole-cell protein fingerprinting of C. albicans oral isolates. A total of 13 major phenons (clusters) were analyzed, according to their homogeneous (socioeconomic category and/or same school) and heterogeneous (distinct socioeconomic categories and/or schools) characteristics. Regarding to the social epidemiological aspect, the cluster composition showed higher similarities (0.788 < S D < 1.0) among C. albicans strains isolated from healthy children independent of their socioeconomic bases (high, medium, or low). Isolates of high similarity were not found in oral cavities from healthy children of social stratum A and D, B and D, or C and E. This may be explained by an absence of a dissemination route among these children. Geographically, some healthy children among identical and different schools (private and public) also are carriers of similar strains but such similarity was not found among other isolates from children from certain schools. These data may reflect a restricted dissemination route of these microorganisms in some groups of healthy scholars, which may be dependent of either socioeconomic categories or geographic site of each child. In contrast to the higher similarity, the lower similarity or higher polymorphism degree (0.499 < S D < 0.788) of protein profiles was shown in 23 (30.6%) C. albicans oral isolates. Considering the social epidemiological aspect, 42.1%, 41.7%, 26.6%, 23.5%, and 16.7% were isolates from children concerning to socioeconomic categories A, D, C, B, and E, respectively, and geographically, 63.6%, 50%, 33.3%, 33.3%, 30%, 25%, and 14.3% were isolates from children from schools LAE (Liceu Colégio Albert Einstein), MA (E.E.P.S.G. "Prof. Elias de Melo Ayres"), CS (E.E.P.G. "Prof. Carlos Sodero"), AV (Alphaville), HF (E.E.P.S.G. "Honorato Faustino), FMC (E.E.P.G. "Prof. Francisco Mariano da Costa"), and MEP (E.E.P.S.G. "Prof. Manasses Ephraim Pereira), respectively. Such results suggest a higher protein polymorphism degree among some strains isolated from healthy children independent of their socioeconomic strata or geographic sites. Complementary studies, involving healthy students and their families, teachers, servants, hygiene and nutritional habits must be done in order to establish the sources of such colonization patterns in population groups of healthy children. The whole-cell protein profile obtained by SDS-PAGE associated with computer-assisted numerical analysis may provide additional criteria for the taxonomic and epidemiological studies of C. albicans.

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Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática

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Fractional dynamics is a growing topic in theoretical and experimental scientific research. A classical problem is the initialization required by fractional operators. While the problem is clear from the mathematical point of view, it constitutes a challenge in applied sciences. This paper addresses the problem of initialization and its effect upon dynamical system simulation when adopting numerical approximations. The results are compatible with system dynamics and clarify the formulation of adequate values for the initial conditions in numerical simulations.

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Recently simple limiting functions establishing upper and lower bounds on the Mittag-Leffler function were found. This paper follows those expressions to design an efficient algorithm for the approximate calculation of expressions usual in fractional-order control systems. The numerical experiments demonstrate the superior efficiency of the proposed method.

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The calculation of fractional derivatives is an important topic in scientific research. While formal definitions are clear from the mathematical point of view, they pose limitations in applied sciences that have not been yet tackled. This paper addresses the problem of obtaining left and right side derivatives when adopting numerical approximations. The results reveal the relationship between the resulting distinct values for different fractional orders and types of signals.

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Software tools in education became popular since the widespread of personal computers. Engineering courses lead the way in this development and these tools became almost a standard. Engineering graduates are familiar with numerical analysis tools but also with simulators (e.g. electronic circuits), computer assisted design tools and others, depending on the degree. One of the main problems with these tools is when and how to start use them so that they can be beneficial to students and not mere substitutes for potentially difficult calculations or design. In this paper a software tool to be used by first year students in electronics/electricity courses is presented. The growing acknowledgement and acceptance of open source software lead to the choice of an open source software tool – Scilab, which is a numerical analysis tool – to develop a toolbox. The toolbox was developed to be used as standalone or integrated in an e-learning platform. The e-learning platform used was Moodle. The first approach was to assess the mathematical skills necessary to solve all the problems related to electronics and electricity courses. Analysing the existing circuit simulators software tools, it is clear that even though they are very helpful by showing the end result they are not so effective in the process of the students studying and self learning since they show results but not intermediate steps which are crucial in problems that involve derivatives or integrals. Also, they are not very effective in obtaining graphical results that could be used to elaborate reports and for an overall better comprehension of the results. The developed tool was based on the numerical analysis software Scilab and is a toolbox that gives their users the opportunity to obtain the end results of a circuit analysis but also the expressions obtained when derivative and integrals calculations, plot signals, obtain vector diagrams, etc. The toolbox runs entirely in the Moodle web platform and provides the same results as the standalone application. The students can use the toolbox through the web platform (in computers where they don't have installation privileges) or in their personal computers by installing both the Scilab software and the toolbox. This approach was designed for first year students from all engineering degrees that have electronics/electricity courses in their curricula.

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This report describes a preliminary characterization of proteolytic activity of proteins isolated from lysate of Giardia trophozoites of an axenic Brazilian strain. Fractions obtained by high-performance liquid chromatography (FPLC) were tested in SDS-polyacrylamide gel for the protein profiles, and the proteases activity was analyzed using gelatin impregnated SDS-PAGE. The proteases characterization was based on inhibition assays employing synthetic inhibitors for cysteine (E-64, IAA), serine (PMSF, TPCK, TLCK, and elastatinal), metalo (EDTA) and aspartic (pepstatin) proteases. Among thirty eluted fractions, polypeptide bands were observed in eight of them, however, proteolytic activity was detected in four ones (F23, F24, F25 and F26). Protein profiles of these fractions showed a banding pattern composed by few bands distributed in the migration region of 45 to < 18 kDa. The zymograms revealed proteolytic activity in all the four fractions assayed, mainly distributed in the migration region of 62 to 35 kDa. Among the profiles, the main pronounced zones of proteolysis were distinguished at 62, 55, 53, 50, 46 and 40 kDa. In inhibition assays, the protease activities were significantly inhibited by cysteine (E-64) and serine proteases (TPCK, TLCK and elastatinal) inhibitors. Gels incubated with other cysteine and serine protease inhibitors, IAA and PMSF, respectively, showed a decrease in the intensity of hydrolysis zones. Indeed, in the assays with the inhibitors EDTA for metalloproteases and pepstatin for aspartic proteases, none inhibition was detected against the substrate. These observations are relevants, especially if we consider that to define the real role of the proteases in host-parasite interaction, the purification of these enzymes for detailed studies may be warranted.

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Clinical history - A 4-year-old boy, born prematurely at 29 weeks (twin pregnancy), with periventricular leukomalacia and epilepsy underwent brain MRI. Neurological examination showed severe developmental retardation with axial hypotonia, spastic tetraparesis and convergent strabismus. Imaging findings - Cranial MRI revealed typical aspects of partial rhombencephalosynapsis with vermian hypoplasia, midline fusion of the cerebellar hemispheres and transversely oriented folia and fissures. There was also mild dilatation and dysmorphism of the ventricular system, the septum pellucidum was absent, the hippocampi were malrotated and had vertical orientation and additional finding of associated periventricular cystic leukomalacia. Discussion - Rhombencephalosynapsis (RS) is a rare congenital defect of the cerebellum classically characterised by vermian agenesis or hypogenesis, fusion of the hemispheres, and closely apposed or fused dentate nuclei. It is now considered to result from an absence of division of the cerebellar hemispheres, following an insult between the 28th and 44th day of gestation (i.e., before the formation of the vermis). Other features have also been described such as fusion of the thalami and cerebral peduncles, malrotated hippocampi, corpus callosum agenesis, hypoplastic chiasm, absence of the septum pellucidum, ventriculomegaly, agenesis of the posterior lobe of the pituitary and cortical malformations. Musculoskeletal, cardiovascular, urinary tract, and respiratory abnormalities have been reported. Typical symptoms consist of swallowing difficulties, delayed motor acquisitions, muscular hypotonia, spastic quadriparesis, cerebellar signs including dysarthria, gait ataxia, abnormal eye movements, and seizures and hydrocephalus. The major MRI signs consist of fused cerebellar hemispheres, with absent or hypoplastic vermis, narrow diamond-shaped fourth ventricle and fused dentate nuclei. In a minority of cases, partial RS has been identified by MRI, demonstrating the presence of the nodulus and the anterior vermis and absence of part of the posterior vermis with only partial fusion of the hemispheres in the inferior part. Other cerebellar malformations involving vermian agenesis or hypoplasia include the Dandy–Walker continuum, Joubert syndrome, tectocerebellar dysraphy or pontocerebellar hypoplasias, and are now easily distinguished from RS by both brain MRI and morphology.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies

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Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente, perfil Engenharia Sanitária