A semigroups theory approach to a model of suspension bridges

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

On a model for the growth of an invasive avascular tumor

This paper is devoted to study the 1D model of invasive avascular tumor growth, which takes into account cell division, death, and motility, proposed by Kolobov and collaborators in 2009. First, we examine the existence and uniqueness of the solution to this model. Second, we studied qualitatively and numerically the traveling wave solutions. Finally, we show some numerical simulations for the cell density and nutrient concentration. © 2013 NSP Natural Sciences Publishing Cor.

Numerical study of the Ginzburg-Landau-Langevin equation: coherent structures and noise perturbation theory

Pós-graduação em Física - IFT

Tópicos de equações diferenciais com retardamento: uma abordagem segundo o trabalho do Prof. Nelson Onuchic

Pós-graduação em Matemática Universitária - IGCE

Ultrastructural Morphology and Nuclear Maturation Rates of Immature Equine Oocytes Vitrified with Different Solutions and Exposure Times

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Exact Solution of the Elastica with Transverse Shear Effects

A new derivation of Euler's Elastica with transverse shear effects included is presented. The elastic potential energy of bending and transverse shear is set up. The work of the axial compression force is determined. The equation of equilibrium is derived using the variation of the total potential. Using substitution of variables an exact solution is derived. The equation is transcendental and does not have a closed form solution. It is evaluated in a dimensionless form by using a numerical procedure. Finally, numerical examples of laminates made of composite material (fiber reinforced) and sandwich panels are provided.

Does the rattle of Crotalus durissus terrificus reveal its dietary history?

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

Expressão diferencial dos genes VuUCP1a e VuUCP1b em caupi sob estresse salino

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aerobic training, but not creatine supplementation, alters the gluteus medius muscle

The aim of the present study was to investigate the effect of oral supplementation of creatine on the muscular responses to aerobic training. Twelve purebred Arabian horses were submitted to aerobic training for 90 d, with and without creatine supplementation, and evaluated with respect to BW and BCS and to the area and frequency of the different types of muscle fibers in the gluteus medius. Supplementation consisted of the daily administration of 75 g of creatine monohydrate mixed into the ration for the 90 d of training. Physical conditioning was conducted on a high-performance treadmill, and training intensity was stipulated by calculating the velocity at which blood lactate reaches 4 mmol/L, determined monthly for each animal. The individual intensity of physical force at 80% of aerobic threshold was established. Morphometry of glutens medius muscle fibers was performed on frozen sections processed for histochemical analysis of myosin adenosine triphosphatase and immunohistochemistry of slow-contracting myosin. The results demonstrated that the animals maintained a moderate BCS without alteration of BW during the course of training, providing evidence of equilibrium between food intake and caloric expenditure during the study period. The present study demonstrated that aerobic training for 90 d caused hypertrophy of fiber types I (P = 0.04), IIA (P = 0.04), and IIX (P = 0.01), as well as an increase in the relative area occupied by type I fibers (P = 0.02) at the expense of type IIX fibers (P = 0.03), resulting in modifications of the contractile and metabolic characteristics of the gluteus medius muscle. It was not possible to show any beneficial effect from creatine on the skeletal muscle characteristics examined.

A Transmission Problem for Euler-Bernoulli beam with Kelvin-Voigt Damping

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

On a moment problem associated with Chebyshev polynomials

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Podolsky's electromagnetic theory on the null-plane gauge

Following the Dirac's technique for constrained systems we performed a detailed analysis of the constraint structure of Podolsky's electromagnetic theory on the null-plane coordinates. The null plane gauge condition was extended to second order theories and appropriate boundary conditions were imposed to guarantee the uniqueness of the inverse of the constraints matrix of the system. Finally, we determined the generalized Dirac brackets of the independent dynamical variables. © 2010 American Institute of Physics.

A teoria de Norbert Elias: uma análise do ser professor

No presente artigo, conforme o entendimento de que modelos te- óricos subsidiam a compreensão de fenômenos investigativos, objetivou-se elucidar os conceitos da teoria sociológica de Norbert Elias, considerando-se que esta é uma excelente fonte de análise para se compreender o universo do ser professor, apesar de o autor não abordar diretamente questões relacionadas ao campo da educação. A partir do conceito de configuração, é possível dizer que a constituição do ser professor resulta das diferentes configurações nas quais ele está imerso, pois, de acordo com Elias, as pessoas (professores, pais, gestores, ministros, alunos etc.) modelam suas ideias a partir de todas as suas experiências e, essencialmente, das experiências vividas no interior do próprio grupo. É observável que as configurações, formadas por grupos interdependentes de pessoas, e não por indivíduos singulares, apresentam-se cada vez mais ampliadas nos contextos escolares, com funções especializadas e específicas (professores, alunos, diretores, coordenadores, supervisores, secretários etc.), em grupos que se tornam cada vez mais funcionalmente dependentes. As cadeias de interdependência estão mais diferenciadas e, consequentemente, mais opacas e dificilmente controláveis por parte de quaisquer grupos ou indiví- duos. Portanto, uma melhor compreensão será possível quando se estudar empiricamente as configurações que estão em jogo na educação brasileira. Daí se justifica a análise das configurações e das teias de interdependência em que os professores estão envolvidos. Enfim, a aplicação dos modelos de competição abordados por Elias possibilita evidenciar as problemáticas sociológicas do ser professor, tornando-as mais evidentes e facilitando o entendimento do jogo para reorganizá-lo em termos de equilíbrio na teia social.

Hamilton-Jacobi formalism to Podolsky electromagnetic theory on the null-plane

In this work we develop the Hamilton - Jacobi formalism to study the Podolsky electromagnetic theory on the null-plane coordinates. We calculate the generators of the Podolsky theory and check the integrability conditions. Appropriate boundary conditions are introduced to assure uniqueness of the Green functions associated to the differential operators. Non-involutive constraints in the Hamilton-Jacobi formalism are eliminated by constructing their respective generalized brackets. © 2013 American Institute of Physics.

On Hepatitis C Virus Evolution: The Interaction between Virus and Host towards Treatment Outcome

Background:Hepatitis C is a disease spread throughout the world. Hepatitis C virus (HCV), the etiological agent of this disease, is a single-stranded positive RNA virus. Its genome encodes a single precursor protein that yields ten proteins after processing. NS5A, one of the non-structural viral proteins, is most associated with interferon-based therapy response, the approved treatment for hepatitis C in Brazil. HCV has a high mutation rate and therefore high variability, which may be important for evading the immune system and response to therapy. The aim of this study was to analyze the evolution of NS5A quasispecies before, during, and after treatment in patients infected with HCV genotype 3a who presented different therapy responses.Methods:Viral RNA was extracted, cDNA was synthesized, the NS5A region was amplified and cloned, and 15 clones from each time-point were sequenced. The sequences were analyzed for evolutionary history, genetic diversity and selection.Results:This analysis shows that the viral population that persists after treatment for most non-responder patients is present in before-treatment samples, suggesting it is adapted to evade treatment. In contrast, the population found in before treatment samples from most end-of-treatment responder patients either are selected out or appears in low frequency after relapse, therefore changing the population structure. The exceptions illustrate the uniqueness of the evolutionary process, and therefore the treatment resistance process, in each patient.Conclusion:Although evolutionary behavior throughout treatment showed that each patient presented different population dynamics unrelated to therapy outcome, it seems that the viral population from non-responders that resists the treatment already had strains that could evade therapy before it started. © 2013 Bittar et al.