917 resultados para Transversal Heteroclinic Cycle
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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In this work we consider the dynamic consequences of the existence of infinite heteroclinic cycle in planar polynomial vector fields, which is a trajectory connecting two saddle points at infinity. It is stated that, although the saddles which form the cycle belong to infinity, for certain types of nonautonomous perturbations the perturbed system may present a complex dynamic behavior of the solutions in a finite part of the phase plane, due to the existence of tangencies and transversal intersections of their stable and unstable manifolds. This phenomenon might be called the chaos arising from infinity. The global study at infinity is made via the Poincare Compactification and the argument used to prove the statement is the Birkhoff-Smale Theorem. (c) 2004 WILEY-NCH Verlag GmbH & Co. KGaA, Weinheim.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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In this work are studied periodic perturbations, depending on two parameters, of planar polynomial vector fields having an annulus of large amplitude periodic orbits, which accumulate on a symmetric infinite heteroclinic cycle. Such periodic orbits and the heteroclinic trajectory can be seen only by the global consideration of the polynomial vector fields on the whole plane, and not by their restriction to any compact set. The global study involving infinity is performed via the Poincare Compactification. It is shown that, for certain types of periodic perturbations, one can seek, in a neighborhood of the origin in the parameter plane, curves C-(m) of subharmonic bifurcations, for which the periodically perturbed system has subharmonics of order m, for any integer m.
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Universidade Estadual de Campinas . Faculdade de Educação Física
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Universidade Estadual de Campinas . Faculdade de Educação Física
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In this paper we will find a continuous of periodic orbits passing near infinity for a class of polynomial vector fields in R3. We consider polynomial vector fields that are invariant under a symmetry with respect to a plane and that possess a “generalized heteroclinic loop” formed by two singular points e+ and e− at infinity and their invariant manifolds � and . � is an invariant manifold of dimension 1 formed by an orbit going from e− to e+, � is contained in R3 and is transversal to . is an invariant manifold of dimension 2 at infinity. In fact, is the 2–dimensional sphere at infinity in the Poincar´e compactification minus the singular points e+ and e−. The main tool for proving the existence of such periodic orbits is the construction of a Poincar´e map along the generalized heteroclinic loop together with the symmetry with respect to .
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En el estudio buscamos caracterizar el análisis de la SOSTENIBILIDAD (Suficiencia) del CICLO DE VIDA de una INFRAESTRUCTURA AEROPORTUARIA centrándonos en la evaluación de los aspectos SOCIALES (de forma Interdisciplinaria o Transversal) que le afectan y considerando todos los AGENTES involucrados (ingenieros/ operadores/ mantenedores/ usuarios/ stakeholders/ etc.). La complejidad de las interacciones entre los edificios y su entorno hace que sea difícil definir y evaluar con precisión la sostenibilidad de un edificio. Las NORMAS AMBIENTALES para la construcción (unas pocas existentes y algunos en fase de desarrollo) se centran en la sostenibilidad ECONÓMICA, SOCIAL Y AMBIENTAL que caracteriza a un edificio, siendo los aspectos socio-económicos difíciles de evaluar. En consecuencia, los métodos existentes para la evaluación de la construcción sostenible (por ejemplo, LEED, BREEAM, SBTool) tienden a superar los aspectos ambientales pues son más fáciles de evaluar de manera cuantitativa. Así desde el punto de vista holístico (global) y utilizando la teoría de sistemas complejos, la sostenibilidad debe ser evaluada, en parte, utilizando los INDICADORES DE SOSTENIBILIDAD SOCIALES Y ECONÓMICOS para cubrir todos los factores de Sostenibilidad. El estudio propone una metodología para valorar la sostenibilidad en la construcción aeroportuaria a través de la evaluación de los indicadores sostenibles de la construcción (SKPIs) sin y superando las carencias presentadas. Para ello hemos implementado una herramienta de evaluación de la sostenibilidad, donde: Puede evaluar, en primer aproximación e independientemente, la sostenibilidad del CICLO DE VIDA de la INFRAESTRUCTURA AEROPORTUARIA Puede COMPLETAR otras herramientas comerciales disponibles (ej. BREEAM, LEED), bajo un enfoque ECONÓMICO-SOCIAL y complementando el enfoque ambiental La evaluación de los KPIs se realiza por medio de TECNOLOGÍAS Y ESTRATEGIAS SOSTENIBLES, cuya aplicación supondría un aumento de la sostenibilidad del edificio La herramienta propuesta considera la complejidad y transdisciplinariedad del problema, fundada en un SISTEMA DE CRÉDITOS fácil de usar. Así el programa diseñado permite el análisis y la comparación del CICLO DE VIDA de la INFRAESTRUCTURA AEROPORTUARIA: Abarcando las etapas de construcción (diseño, operación, mantenimiento, etc.) Incluyendo a todos los agentes de construcción (ocupantes, stakeholders, constructores, etc.) Finalmente, se aporta un ejemplo teórico de una INFRAESTRUCTURA AEROPORTUARIA (Terminal Aeroportuaria) para fijar, demostrar y discutir el estudio presentado Abstract We seek to characterize the sustainability analysis of the life cycle of a building focus us on the evaluation of social aspect. From a holistic point of view and using complex systems theory, sustainability must be evaluated, in part, using social key performance indicator (KPI) to cover all factors of sustainability. The most remarkable of the proposed framework is to provide a methodology to achieve the sustainability in construction through the assessment of social KPIs. Besides we implement a tool to assess sustainability, where this tool could complete other commercial tools available (e.g. BREEAM, LEED). The proposed tool considers the complexity and trans-disciplinary of the problem. The procedure is based on a credit system easy to use. It also allows analysis and comparison of the boundary conditions of the building, embracing construction stages (design, operation), involving all the building agents (occupants, stakeholders, etc.)
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Relatório final apresentado para a obtenção do grau de mestre em Educação pré-escolar e 1º ciclo do ensino básico.
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Relatório final apresentado para a obtenção do grau de mestre em Educação pré-escolar e 1º ciclo do ensino básico.
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The growth of organs and whole plants depends on both cell growth and cell-cycle progression, but the interaction between both processes is poorly understood. In plants, the balance between growth and cell-cycle progression requires coordinated regulation of four different processes: macromolecular synthesis (cytoplasmic growth), turgor-driven cell-wall extension, mitotic cycle, and endocycle. Potential feedbacks between these processes include a cell-size checkpoint operating before DNA synthesis and a link between DNA contents and maximum cell size. In addition, key intercellular signals and growth regulatory genes appear to target at the same time cell-cycle and cell-growth functions. For example, auxin, gibberellin, and brassinosteroid all have parallel links to cell-cycle progression (through S-phase Cyclin D-CDK and the anaphase-promoting complex) and cell-wall functions (through cell-wall extensibility or microtubule dynamics). Another intercellular signal mediated by microtubule dynamics is the mechanical stress caused by growth of interconnected cells. Superimposed on developmental controls, sugar signalling through the TOR pathway has recently emerged as a central control point linking cytoplasmic growth, cell-cycle and cell-wall functions. Recent progress in quantitative imaging and computational modelling will facilitate analysis of the multiple interconnections between plant cell growth and cell cycle and ultimately will be required for the predictive manipulation of plant growth.
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Schistosomiasis is a common tropical disease caused by Schistosoma species Schistosomiasis' pathogenesis is known to vary according to the worms' strain. Moreover, high parasitical virulence is directly related to eggs release and granulomatous inflammation in the host's organs. This virulence might be influenced by different classes of molecules, such as lipids. Therefore, better understanding of the metabolic profile of these organisms is necessary, especially for an increased potential of unraveling strain virulence mechanisms and resistance to existing treatments. In this report, direct-infusion electrospray high-resolution mass spectrometry (ESI(+)-HRMS) along with the lipidomic platform were employed to rapidly characterize and differentiate two Brazilian S. mansoni strains (BH and SE) in three stages of their life cycle: eggs, miracidia and cercariae, with samples from experimental animals (Swiss/SPF mice). Furthermore, urine samples of the infected and uninfected mice were analyzed to assess the possibility of direct diagnosis. All samples were differentiated using multivariate data analysis, PCA, which helped electing markers from distinct lipid classes; phospholipids, diacylglycerols and triacylglycerols, for example, clearly presented different intensities in some stages and strains, as well as in urine samples. This indicates that biochemical characterization of S. mansoni may help narrowing-down the investigation of new therapeutic targets according to strain composition and aggressiveness of disease. Interestingly, lipid profile of infected mice urine varies when compared to control samples, indicating that direct diagnosis of schistosomiasis from urine may be feasible.
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The role of key cell cycle regulation genes such as, CDKN1B, CDKN2A, CDKN2B, and CDKN2C in sporadic medullary thyroid carcinoma (s-MTC) is still largely unknown. In order to evaluate the influence of inherited polymorphisms of these genes on the pathogenesis of s-MTC, we used TaqMan SNP genotyping to examine 45 s-MTC patients carefully matched with 98 controls. A multivariate logistic regression analysis demonstrated that CDKN1B and CDKN2A genes were related to s-MTC susceptibility. The rs2066827*GT+GG CDKN1B genotype was more frequent in s-MTC patients (62.22%) than in controls (40.21%), increasing the susceptibility to s-MTC (OR=2.47; 95% CI=1.048-5.833; P=0.038). By contrast, the rs11515*CG+GG of CDKN2A gene was more frequent in the controls (32.65%) than in patients (15.56%), reducing the risk for s-MTC (OR=0.174; 95% CI=0.048-0.627; P=0.0075). A stepwise regression analysis indicated that two genotypes together could explain 11% of the total s-MTC risk. In addition, a relationship was found between disease progression and the presence of alterations in the CDKN1A (rs1801270), CDKN2C (rs12885), and CDKN2B (rs1063192) genes. WT rs1801270 CDKN1A patients presented extrathyroidal tumor extension more frequently (92%) than polymorphic CDKN1A rs1801270 patients (50%; P=0.0376). Patients with the WT CDKN2C gene (rs12885) presented larger tumors (2.9±1.8 cm) than polymorphic patients (1.5±0.7 cm; P=0.0324). On the other hand, patients with the polymorphic CDKN2B gene (rs1063192) presented distant metastases (36.3%; P=0.0261). In summary, we demonstrated that CDKN1B and CDKN2A genes are associated with susceptibility, whereas the inherited genetic profile of CDKN1A, CDKN2B, and CDKN2C is associated with aggressive features of tumors. This study suggests that profiling cell cycle genes may help define the risk and characterize s-MTC aggressiveness.
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Universidade Estadual de Campinas. Faculdade de Educação Física
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Universidade Estadual de Campinas . Faculdade de Educação Física