Stochastic Walk
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. Funções generalizadas, modelos de crescimento contínuos e discretos e caminhadas estocásticas em meios desordenados / Generalized functions, discrete and continuous growth models and stochastic walks on disordered media
Este trabalho está divido em duas partes. Na primeira apresentamos as funções logaritmo e exponencial generalizadas. A partir delas uma grande variedade de outras funções generalizadas pode ser obtida, permitindo uma formulação única dos comportamentos oscilatório, exponencial e lei de potência, característicos dos principais fenômenos físicos.
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/07/2011
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2. Superdifusão de caminhadas markovianas e não-markovianas. / Superdifusion of marcovian na non-marcovian walk.
Random walks are tools used in statistical physics to quantitatively describe the evolution of dynamical systems. Such systems are ubiquitous in Nature and each system requires a unique approach. Models of the motion of biological organisms are constructed based on the randomness observed in search strategies. Markovian models attempt to faithfully reproduce
Publicado em: 2010
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3. Transição entre os comportamentos estendido e localizado em caminhadas estocásticas parcialmente auto-repulsivas em sistemas desordenados unidimensionais / Transition between the extended and localized regimes in stochastic partially self-avoiding walks in one-dimensional disordered systems
Consider $N$ sites randomly and uniformly distributed in a $d$-dimensional hypercube. A walker explores this disordered medium going to the nearest site, which has not been visited in the last $\mu$ (memory) steps. The walker trajectory is composed of a transient part and a periodic part (cycles). In this case, travelers can or cannot explore all available s
Publicado em: 2009
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4. Modelos estocásticos e de rede no estudo de mecanismos de adsorção e difusão em adsorventes porosos / Stochastic and network models in the study of adsorption and diffusion mechanisms in porous adsorbents
A compreensão dos fenômenos de adsorção e difusão em superfícies é fundamental no desenvolvimento de materiais de alto rendimento utilizados em uma série de processos de grande relevância industrial. A modelagem de materiais adsorventes porosos através de modelos de rede tem seu potencial uma vez que se pode estudar os fenômenos a nível microscó
Publicado em: 2009
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5. Aspectos especiais e temporais do problema do enovelamento protÃico
The manner in which a protein folds from a random coil into a unique native state in a relatively short time is one of the fundamental puzzles of molecular biophysics. It is well accepted that a unique native three-dimensional structure, characteristic of each protein and determined by the sequence of its amino-acids, dictates protein functions. In this Thes
Publicado em: 2002
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6. Explaining mortality rate plateaus
We propose a stochastic model of aging to explain deviations from exponential growth in mortality rates commonly observed in empirical studies. Mortality rate plateaus are explained as a generic consequence of considering death in terms of first passage times for processes undergoing a random walk with drift. Simulations of populations with age-dependen
The National Academy of Sciences.
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7. Time course of reactions controlled and gated by intramolecular dynamics of proteins: Predictions of the model of random walk on fractal lattices
Computer simulations of random walk on the Sierpiński gasket and percolation clusters demonstrate that the short, initial condition-dependent stage of protein involving reactions can dominate the progress of the reaction over the main stage described by the standard kinetics. This phenomenon takes place if the intramolecular conformational transition dynami
The National Academy of Sciences.
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8. Molecular motors: thermodynamics and the random walk.
The biochemical cycle of a molecular motor provides the essential link between its thermodynamics and kinetics. The thermodynamics of the cycle determine the motor's ability to perform mechanical work, whilst the kinetics of the cycle govern its stochastic behaviour. We concentrate here on tightly coupled, processive molecular motors, such as kinesin and myo
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9. Autonomous T cell trafficking examined in vivo with intravital two-photon microscopy
The recirculation of T cells between the blood and secondary lymphoid organs requires that T cells are motile and sensitive to tissue-specific signals. T cell motility has been studied in vitro, but the migratory behavior of individual T cells in vivo has remained enigmatic. Here, using intravital two-photon laser microscopy, we imaged the locomotion and tra
The National Academy of Sciences.
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10. Inversely correlated cycles in speed and turning in an ameba: an oscillatory model of cell locomotion.
Previous biophysical models of ameboid crawling have described cell movement in terms of a persistent random walk. Speed and orientation were treated in the latter model as independent and temporally homogeneous stochastic processes. We show here that, at least in the case of Dictyostelium discoideum, both speed control and reorientation processes involve a
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11. A random-walk model for helix bending in B-DNA.
The double-helical B-DNA dodecamer of sequence d(C-G-C-G-A-A-T-T-C-G-C-G) has been refined independently from x-ray crystal structure analyses in five different variants: d(C-G-C-G-A-A-T-T-C-G-C-G) at 16 K, at room temperature, and with bound cis-diamminedichloroplatinum(II), and d(C-G-C-G-A-A-T-T-brC-G-C-G) in 60% 2-methyl-2,4-pentanediol at 20 degrees C an
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12. E. coli Superdiffusion and Chemotaxis—Search Strategy, Precision, and Motility
Escherichia coli motion is characterized by a sequence of consecutive tumble-and-swim events. In the absence of chemical gradients, the length of individual swims is commonly believed to be distributed exponentially. However, recently there has been experimental indication that the swim-length distribution has the form of a power-law, suggesting that bacteri
The Biophysical Society.