Locating invariant tori for a family of two-dimensional Hamiltonian mappings

The location of invariant tori for a two-dimensional Hamiltonian mapping exhibiting mixed phase space is discussed. The phase space of the mapping shows a large chaotic sea surrounding periodic islands and limited by a set of invariant tori. Given the mapping considered is parameterised by an exponent γ in one of the dynamical variables, a connection with the standard mapping near a transition from local to global chaos is used to estimate the position of the invariant tori limiting the size of the chaotic sea for different values of the parameter γ. © 2011 Elsevier B.V. All rights reserved.

Aspectos Históricos e organizacionais da agricultura familiar no desenvolvimento da região Nova Alta Paulista

Nova Alta Paulista region, with strong aptitude for agribusiness, is one of the poorest in the state of São Paulo. However, the development of agribusiness productive chains in the region is very heterogeneous. The study aimed at analyzing how the historical background and organizational arrangements in family farming have contributed to regional development by promoting improvements in social welfare at Nova Alta Paulista region. To this end, we analyzed the case of the Associação Agrícola de Junqueirópolis - AAJ, an organization that has been successful in the search for alternative of agricultural production. Integrated to local and global market, this organization has ensured the maintenance of many farmers and generated positive externalities for the entire region. Thus, this case shows the organizational arrangement based on cooperation can be an alternative for family farmers achieve higher levels of welfare and development.

Antagonist coactivation of trunk stabilizer muscles during Pilates exercises

The purpose of this study was to compare the antagonist coactivation of the local and global trunk muscles during mat-based exercises of Skilled Modern Pilates. Twelve women performed five exercises and concurrently, surface EMG from internal oblique (OI), multifidus (MU), rectus abdominis (RA) and iliocostalis lumborum (IL) muscles was recorded bilaterally. The percentage of antagonist coactivation between local (OI/MU) and global muscles (RA/IL) was calculated. Individuals new to the practice of these exercises showed differences in coactivation of the trunk muscles between the exercises and these results were not similar bilaterally. Thus, in clinical practice, the therapist should be aware of factors such as compensation and undesirable rotation movements of the trunk. Moreover, the coactivation of global muscles was higher bilaterally in all exercises analyzed. This suggests that the exercises of Skilled Modern Pilates only should be performed after appropriate learning and correct execution of all principles, mainly the Centering Principle. © 2013 Elsevier Ltd. All rights reserved.

A rescaling of the phase space for Hamiltonian map: Applications on the Kepler map and mappings with diverging angles in the limit of vanishing action

A rescale of the phase space for a family of two-dimensional, nonlinear Hamiltonian mappings was made by using the location of the first invariant Kolmogorov-Arnold-Moser (KAM) curve. Average properties of the phase space are shown to be scaling invariant and with different scaling times. Specific values of the control parameters are used to recover the Kepler map and the mapping that describes a particle in a wave packet for the relativistic motion. The phase space observed shows a large chaotic sea surrounding periodic islands and limited by a set of invariant KAM curves whose position of the first of them depends on the control parameters. The transition from local to global chaos is used to estimate the position of the first invariant KAM curve, leading us to confirm that the chaotic sea is scaling invariant. The different scaling times are shown to be dependent on the initial conditions. The universality classes for the Kepler map and mappings with diverging angles in the limit of vanishing action are defined. © 2013 Published by Elsevier Inc. All rights reserved.

Ergodic crossover in partially self-avoiding stochastic walks

Consider a one-dimensional environment with N randomly distributed sites. An agent explores this random medium moving deterministically with a spatial memory μ. A crossover from local to global exploration occurs in one dimension at a well-defined memory value μ1=log2N. In its stochastic version, the dynamics is ruled by the memory and by temperature T, which affects the hopping displacement. This dynamics also shows a crossover in one dimension, obtained computationally, between exploration schemes, characterized yet by the trajectory size (Np) (aging effect). In this paper we provide an analytical approach considering the modified stochastic version where the parameter T plays the role of a maximum hopping distance. This modification allows us to obtain a general analytical expression for the crossover, as a function of the parameters μ, T, and Np. Differently from what has been proposed by previous studies, we find that the crossover occurs in any dimension d. These results have been validated by numerical experiments and may be of great value for fixing optimal parameters in search algorithms. © 2013 American Physical Society.

Basic ingredients for mathematical modeling of tumor growth in vitro: Cooperative effects and search for space

Based on the literature data from HT-29 cell monolayers, we develop a model for its growth, analogous to an epidemic model, mixing local and global interactions. First, we propose and solve a deterministic equation for the progress of these colonies. Thus, we add a stochastic (local) interaction and simulate the evolution of an Eden-like aggregate by using dynamical Monte Carlo methods. The growth curves of both deterministic and stochastic models are in excellent agreement with the experimental observations. The waiting times distributions, generated via our stochastic model, allowed us to analyze the role of mesoscopic events. We obtain log-normal distributions in the initial stages of the growth and Gaussians at long times. We interpret these outcomes in the light of cellular division events: in the early stages, the phenomena are dependent each other in a multiplicative geometric-based process, and they are independent at long times. We conclude that the main ingredients for a good minimalist model of tumor growth, at mesoscopic level, are intrinsic cooperative mechanisms and competitive search for space. © 2013 Elsevier Ltd.

Agricultura tradicional e a manutenção da agrobidiversidade em comunidades rurais do município de Santo Antonio de Leverger - MT

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A vós suspiramos neste trem da vida: catolicismo, criação religiosa e identidade na devoção a Nossa Senhora Aparecida do Vagão Queimado de Ourinhos-SP (1954-2006)

Pós-graduação em História - FCLAS

Estudo de uma equação de onda não-linear

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Poluição do ar por veículos automotores e tipos de tempo em áreas metropolitanas: a elaboração de um roteiro metodológico

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Consórcio intermunicipal para o manejo integrado de lixo em cinco municípios da região administrativa de Bauru

Pós-graduação em Geografia - IGCE

Análise do efeito interativo de falhas em processos de manufatura através de projeto de experimentos simulados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desafios e possibilidades: a luta por (re) costurar a vida

Pós-graduação em Serviço Social - FCHS

Statistical and dynamical properties of a dissipative kicked rotator

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

Análise ambiental do comércio bilateral Brasil - China

A estrutura do comércio bilateral entre o Brasil e a República Popular da China - China alterou-se ao longo das décadas de 1990 e 2000 e dos anos 2010 e 2011, que correspondem ao período de análise. Os indicadores monetários e físicos aqui utilizados sugerem que essa relação bilateral de comércio apresenta impacto negativo sobre o meio ambiente e uma tendência exponencial deste impacto. Os indicadores físicos parecem permitir uma extrapolação maior do que os monetários: apesar da China estar contribuindo com uma parcela maior com as mudanças climáticas - maior valor absoluto de emissão de CO2 das exportações -, o Brasil está contribuindo proporcionalmente mais do que aquele país para a insustentabilidade global. Assim, a dinâmica dessa estrutura aponta para aumento da vulnerabilidade do setor exportador brasileiro, tanto no aspecto ambiental como no tecnológico, fator primordial para minimização do impacto sobre o ecossistema local e global