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Search Results: 1 - 10 of 107819 matches for " Jose' Carlos Cavalheiro Da Silveira "
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Another look at ADHD
Vania Lucia De Morais Ribeiro,Jose' Carlos Cavalheiro Da Silveira
Dialogues in Philosophy, Mental and Neuro Sciences , 2009,
Aspectos fenomenológicos do conceito de rede: o Aleph, ubiqüidades
Antonio Zumpano,José Carlos Cavalheiro da Silveira,Marco Ant?nio de Oliveira,Maria Antonieta Pereira
Caligrama : Revista de Estudos Romanicos , 2003,
Abstract: Resumo: O artigo analisa o conceito de infinito na literatura de Jorge Luis Borges. Mostra como a literatura é capaz de tecer uma malha relacional criando situa es para que conceitos oriundos de vários saberes possam ser aprendidos. Palavras-chave: Literatura argentina; Jorge Luis Borges; matemática; infinito. Resumen: El artículo analiza el concepto del infinito en la literatura de Jorge Luis Borges. Demuestra como la literatura es capaz de tejer una malla relacional creando situaciones para que conceptos venidos de varios saberes puedan ser aprehendidos. Palabras-clave: Literatura argentina; Jorge Luis Borges; matemática; infinito.Keywords: Argentinian literature; Jorge Luis Borges; mathematics; infinity.
Radionuclide Transport in Fractured Rock: Numerical Assessment for High Level Waste Repository
Claudia Siqueira da Silveira,Antonio Carlos Marques Alvim,Jose de Jesus Rivero Oliva
Science and Technology of Nuclear Installations , 2013, DOI: 10.1155/2013/827961
Abstract: Deep and stable geological formations with low permeability have been considered for high level waste definitive repository. A common problem is the modeling of radionuclide migration in a fractured medium. Initially, we considered a system consisting of a rock matrix with a single planar fracture in water saturated porous rock. Transport in the fracture is assumed to obey an advection-diffusion equation, while molecular diffusion is considered the dominant mechanism of transport in porous matrix. The partial differential equations describing the movement of radionuclides were discretized by finite difference methods, namely, fully explicit, fully implicit, and Crank-Nicolson schemes. The convective term was discretized by the following numerical schemes: backward differences, centered differences, and forward differences. The model was validated using an analytical solution found in the literature. Finally, we carried out a simulation with relevant spent fuel nuclide data with a system consisting of a horizontal fracture and a vertical fracture for assessing the performance of a hypothetical repository inserted into the host rock. We have analysed the bentonite expanded performance at the beginning of fracture, the quantified radionuclide released from a borehole, and an estimated effective dose to an adult, obtained from ingestion of well water during one year. 1. Introduction With the advent of nuclear technology, countries that employ it received many benefits from the energy production increase, but, as occurs to any activity related to industrialization, there is inevitably a waste production, but the volume of radioactive waste produced is very small, when compared with other industrial residues. The relatively long half-lives of some radionuclides present in this material, as well as their high activity and toxicity, pose a burden for the present and future generation. Part of this waste, the high level waste resulting from reprocessing and spent fuel disposal (HLW—high level waste), remains hazardous for thousands of years and therefore should be carefully stored, using barriers that delay the migration of radioisotopes to the biosphere. Thus, the greatest challenge involves the management of high level radioactive waste, which must be isolated from the environment, and a disposal site for this waste, chosen to ensure safety for many thousands of years, OECD [1]. Although it is impossible to establish a safe depth, for which the biosphere could be effectively isolated from the buried radioactive wastes, it is recognized that a deep repository
Eduardo Cavalheiro Jardim,Rosa Lima da Silva,Suzete Silveira Fichtner
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v17i1.2500
Abstract: Sera obtained from 418 adult bovines were examined by the rapid microscopic agglutination test. There were 20.75% positive reactions for different leptospiral serotypes. Based on the frequency of positive reacting sera for the utilized sorotypes, the serotypes Wotfii were the most frequent, followed by pomona, icterohaemorrhagiae and Grippotyphosa. Foram analisados os hemossoros de 418 bovinos adultos, procedentes de seis municípios do Estado de Goiás, com rela o à existência de aglutininas antileptospira. A porcentagem de animais positivos foi de 20,57%, sendo mais encontrados os sorotipos Wolfii, seguido de pomona, do icterohaemorrhagiae e do gripotyphosa, com o maior número de resultados ocorrendo no título de 1:1600.
Suzete Silveira Fichtner,Eduardo Cavalheiro Jardim,Jacy Luiz da Costa
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v18i1.2557
Abstract: Age at first calving was studied in 136 dams: 97 Polled Tabapu and 39 Polled Nelore in experimental farm of Itau ú, Goiás. The average age at first calving was 36,8 ± 3,0 months to Polled Tabapu and 35,8 ± 1,9 months to cows Polled Nelore. There was no significant difference (P > 0,05) between two breeds. The most calving was between 35 and 37 months of age in cows. Foi estudada a informa o existente na Fazenda Experimental de Itau ú (GO), da Secretaria da Agricultura de Goiás, relativa à idade ao primeiro parto de 136 pari es de vacas, sendo 97 da ra a mocho Tabapu , e 39 Nelore mocho, encontrando-se o valor médio de 36,8 ± 3,0 meses para as vacas da ra a mocho Tabapu e de 35,8 ± 1,9 meses para as ra as Nelore mocho. N o foi encontrada diferen a estatística entre as ra as estudadas (P > 0,05). Observou-se, ainda, que a maior percentagem de partos ocorreu entre os 35 e 37 meses de idade das vacas.
Wood cross-arms coated with polyurethane resin - tests and numerical simulations
Altafim, Ruy Alberto Correa;Silva, Jose Francisco Resende da;Gonzaga, Diógenes Pereira;Ribeiro, Cacilda;Godoy, Jo?o;Basso, Heitor Curry;Bueno, Benedito;Calil Júnior, Carlito;Sartori, Jose Carlos;Altafim, Ruy Alberto Pisani;Silveira, Alex;
Materials Research , 2006, DOI: 10.1590/S1516-14392006000100015
Abstract: brazil's electric power utilities have commonly employed native timbers as the main material for manufacturing cross-arms for distribution lines. however, the increasingly high costs of these timbers and brazil's new environmental laws have contributed to change this situation, spurring research on new materials for application in transmission and distribution systems. this paper discusses two reforested wood species, pinus elliottii and eucalyptus citriodora, coated with castor oil-based polyurethane resins, as an alternative material for distribution line cross-arms, from the standpoint of their mechanical and electrical properties and their low cost. numerical simulations and a complete description of the entire coating process are also part of this work.
Alcohol Abuse Promotes Changes in Non-Synaptic Epileptiform Activity with Concomitant Expression Changes in Cotransporters and Glial Cells
Luiz Eduardo Canton Santos, Gilcélio Amaral da Silveira, Victor Diego Cupertino Costa, Aline Gisele Batista, Ana Paula Madureira, Ant?nio Márcio Rodrigues, Carla Alessandra Scorza, Henrique Alves Amorim, Ricardo Mário Arida, Mario Ant?nio Duarte, Fúlvio Alexandre Scorza, Esper Abr?o Cavalheiro, Ant?nio-Carlos Guimar?es de Almeida
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0078854
Abstract: Non-synaptic mechanisms are being considered the common factor of brain damage in status epilepticus and alcohol intoxication. The present work reports the influence of the chronic use of ethanol on epileptic processes sustained by non-synaptic mechanisms. Adult male Wistar rats administered with ethanol (1, 2 e 3 g/kg/d) during 28 days were compared with Control. Non-synaptic epileptiform activities (NEAs) were induced by means of the zero-calcium and high-potassium model using hippocampal slices. The observed involvement of the dentate gyrus (DG) on the neurodegeneration promoted by ethanol motivated the monitoring of the electrophysiological activity in this region. The DG regions were analyzed for the presence of NKCC1, KCC2, GFAP and CD11b immunoreactivity and cell density. The treated groups showed extracellular potential measured at the granular layer with increased DC shift and population spikes (PS), which was remarkable for the group E1. The latencies to the NEAs onset were more prominent also for the treated groups, being correlated with the neuronal loss. In line with these findings were the predispositions of the treated slices for neuronal edema after NEAs induction, suggesting that restrict inter-cell space counteracts the neuronal loss and subsists the hyper-synchronism. The significant increase of the expressions of NKCC1 and CD11b for the treated groups confirms the existence of conditions favorable to the observed edematous necrosis. The data suggest that the ethanol consumption promotes changes on the non-synaptic mechanisms modulating the NEAs. For the lower ethanol dosage the neurophysiological changes were more effective suggesting to be due to the less intense neurodegenertation.
Enhanced Synaptic Connectivity in the Dentate Gyrus during Epileptiform Activity: Network Simulation
Keite Lira de Almeida Fran?a,Ant?nio-Carlos Guimar?es de Almeida,Antonio Fernando Catelli Infantosi,Mario Ant?nio Duarte,Gilcélio Amaral da Silveira,Fulvio Alexandre Scorza,Ricardo Mario Arida,Esper Abr?o Cavalheiro,Ant?nio Márcio Rodrigues
Computational Intelligence and Neuroscience , 2013, DOI: 10.1155/2013/949816
Abstract: Structural rearrangement of the dentate gyrus has been described as the underlying cause of many types of epilepsies, particularly temporal lobe epilepsy. It is said to occur when aberrant connections are established in the damaged hippocampus, as described in human epilepsy and experimental models. Computer modelling of the dentate gyrus circuitry and the corresponding structural changes has been used to understand how abnormal mossy fibre sprouting can subserve seizure generation observed in experimental models when epileptogenesis is induced by status epilepticus. The model follows the McCulloch-Pitts formalism including the representation of the nonsynaptic mechanisms. The neuronal network comprised granule cells, mossy cells, and interneurons. The compensation theory and the Hebbian and anti-Hebbian rules were used to describe the structural rearrangement including the effects of the nonsynaptic mechanisms on the neuronal activity. The simulations were based on neuroanatomic data and on the connectivity pattern between the cells represented. The results suggest that there is a joint action of the compensation theory and Hebbian rules during the inflammatory process that accompanies the status epilepticus. The structural rearrangement simulated for the dentate gyrus circuitry promotes speculation about the formation of the abnormal mossy fiber sprouting and its role in epileptic seizures. 1. Introduction Epileptic syndromes are a group of neurological disorders with different etiology and clinics characterized by recurrent seizures with excessive and hypersynchronous neuronal activity [1]. Nowadays, approximately 50 million people are affected with epilepsy and 40% of which are classified as temporal lobe epilepsy (TLE) [2]. The human TLE is frequently associated with neuronal loss in the hippocampus and dentate gyrus (DG) [3]. Throughout this degeneration, called hippocampal sclerosis, the granule cells are less affected. The neurotransmitter gamma-aminobutyric acid and proteins expressed in these cells are allegedly responsible for neuroprotection, increasing resistance to excitatory injury [4]. The DG has been proposed to be a gate for entry of intense neuronal activity into the hippocampus. However, in TLE, the synaptic reorganization involving the DG granule cells (abnormal sprouting of hippocampal mossy fibers) may act to reduce the DG filtration properties, increasing the propensity to intensify the neuronal activity and, therefore, the seizure propagation through the hippocampus and other limbic system structures [5]. Mossy fiber sprouting
Eduardo Cavalheiro Jardim,Suzete Silveira Fichtner,Rosa Lima da Silva,Dinis Louren?o da Silva
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v9i1.2361
Abstract: Foram examinados 156 soros de suínos, sem ra a definida, de ambos os sexos, com a idade variando de 8 a 15 meses, procedentes de nove municípios goianos e abatidos em matadouro na cidade de Goiania (GO). Os autores assinalaram a prevalência média de 31,5%, e a presen a dos sorotipos grypothyphosa — 27,6% e o wolffi — 3,9%. N o foram assinalados outros sorotipos encontrados pelos autores consultados, o que indica a necessidade de serem continuados os estudos a respeito do assunto. 156 swine, in 9 counties of the state of Goiás, Brazil, were examined by the rapid microscopic agglutination test. There were 31.5% positive reactions for different serotypes. Based on the frequency of positive reacting for the utilized serotypes, the serotypes grypothyphosa (27.6%) was the most frequent, followed by wolffi (3.9%).
Jacy Luiz da Costa,Suzete Silveira Fichtner,Eduardo Cavalheiro Jardim,Túlio Márcio G. Ribeiro
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v8i1.2328
Abstract: Pela análise dos dados do presente estado, o peso médio ao nascer dos bezerros machos foi superior ao das fêmeas, tanto da ra a Nelore Mocho como da Mocho Tabapu , pertencentes à Fazenda Experimental de Itau u, da Secretaria da Agricultura do Estado de Goiás. Os machos da ra a Nelore Mocho apresentaram o peso (kg) ao nascer de 31,92 ± 2,84 e as fêmeas de 30,63 +/- 2,53. Os machos da ra a Tabapu apresentaram o peso médio (kg) de 33,28 +/- 3,52 e o das fêmeas foi de 30,80 +/- 2,54 kg. Birth weight data were taken in Nelore Polled (85 males and 79 females) and in Polled Tabapu calves ( 130 males and 117 females) born from 1975 to 1978 at Itau u Experimental Farm, Goiás - Brazil. The average results were the following (in kg): Nelore Polled males: 31.92 ± 2.84; Nelore Polled females: 30.63 +/- 2.53; Polled Tabapu : males 33. 28 +/- 3.52 and Polled Tabapu females 30.80 +/- 2.54.
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