Brownian Movements
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Movimento browniano com respeito a métricas riemannianas dependendo do tempo e aplicações ao fluxo de curvatura média / Brownian motion with respect to riemannian metrics depending on time and applications to the mean curvature flow
Neste trabalho estudamos o movimento Browniano, sobre uma variedade Riemanniana munida de métricas que variam com respeito ao tempo. Tratamos brevemente os conceitos de semimartingale, equações diferenciáveis estocásticas e processos de difusão sobre variedades diferenciáveis. Apresentamos a construção clássica do movimento Browniano sobre uma vari
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/04/2011
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2. Estudo do acoplamento efetivo entre duas particulas brownianas quanticas / Study of effective coupling between two quantum Brownian particles
We use the system-plus-reservoir model to study the dynamics of a system of two particles that interact with a heat bath in thermal equilibrium, but do not interact with each other. We present an extension of the bath of oscillators capable of inducing an effective coupling between the brownian particles depending on the choice made to the spectral function
Publicado em: 2006
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3. Dissipação, termalização e descoerencia via acoplamento caotico / Dissipation, thermalization and decoherence through chaotic coupling
We study here how and under which conditions a chaotic system with only two degrees of freedom can produce irreversible phenomena such as dissipation, thermalization and, from the quantum point of view, decoherence in a simple system coupled to it. In the classical formulation of the problem, we describe analytically the behavior of the energy ux in Linear R
Publicado em: 2006
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4. Homotopia de trajetorias de sistemas dinamicos / Homotopy of trajectories of dynamical systems
Este trabalho aborda a homotopia monotônica, uma variante apropriada de homotopia, de trajetórias de sistemas de controle. Primeiro é introduzido um conceito de regularidade para funções de controle e depois é considerada a definição de homotopia monotônica de trajetórias regulares de um sistema de controle sigma evoluindo sobre uma variedade M. Em
Publicado em: 2005
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5. Intestinal Coccidia (Apicomplexa: Eimeriidae) of Brazilian Lizards. Eimeria carmelinoi n.sp., from Kentropyx calcarata and Acroeimeria paraensis n.sp. from Cnemidophorus lemniscatus lemniscatus (Lacertilia: Teiidae)
Eimeria carmelinoi n.sp., is described in the teiid lizard Kentropyx calcarata Spix, 1825 from north Brazil. Oocysts subspherical to spherical, averaging 21.25 x 20.15 µm. Oocyst wall smooth, colourless and devoid of striae or micropyle. No polar body or conspicuous oocystic residuum, but frequently a small number of fine granules in Brownian movement. Spor
Memórias do Instituto Oswaldo Cruz. Publicado em: 2002-03
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6. Detection of temporary lateral confinement of membrane proteins using single-particle tracking analysis.
Techniques such as single-particle tracking allow the characterization of the movements of single or very few molecules. Features of the molecular trajectories, such as confined diffusion or directed transport, can reveal interesting biological interactions, but they can also arise from simple Brownian motion. Careful analysis of the data, therefore, is nece
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7. Cell motility driven by actin polymerization.
Certain kinds of cellular movements are apparently driven by actin polymerization. Examples include the lamellipodia of spreading and migrating embryonic cells, and the bacterium Listeria monocytogenes, that propels itself through its host's cytoplasm by constructing behind it a polymerized tail of cross-linked actin filaments. Peskin et al. (1993) formulate
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8. Confined lateral diffusion of membrane receptors as studied by single particle tracking (nanovid microscopy). Effects of calcium-induced differentiation in cultured epithelial cells.
The movements of E-cadherin, epidermal growth factor receptor, and transferrin receptor in the plasma membrane of a cultured mouse keratinocyte cell line were studied using both single particle tracking (SPT; nanovid microscopy) and fluorescence photobleaching recovery (FPR). In the SPT technique, the receptor molecules are labeled with 40 nm-phi colloidal g
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9. Direct observation of brownian motion of lipids in a membrane.
Nanovid microscopy, which uses 30- to 40-nm colloidal gold probes combined with video-enhanced contrast, can be used to examine random and directed movements of individual molecules in the plasma membrane of living cells. To validate the technique in a model system, the movements of lipid molecules were followed in a supported, planar bilayer containing fluo
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10. High-resolution tracking of microtubule motility driven by a single kinesin motor.
Kinesin is a microtubule-based motor protein that contains two identical force-generating subunits. The kinesin binding sites along the microtubule lie 8 nm apart (the dimension of the tubulin dimer), which implies that kinesin must translocate a minimum distance of 8 nm per hydrolysis cycle. Measurements of kinesin's microtubule-stimulated ATPase activity (