25 research outputs found

    Active Brownian Particles. From Individual to Collective Stochastic Dynamics

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    We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

    CP Asymmetries in B_s Decays and Spontaneous CP violation

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    We study possible effects of new physics in CP asymmetries in two-body BsB_s decays in left-right models with spontaneous CP violation. Considering the contributions of new CP phases to the BsB_s mixing as well as to the penguin dominated decay amplitudes we show that, with the present constraints, large deviations from the standard model predictions in CP asymmetries are allowed in both cases. Detection of the new physics can be done by measuring non-zero asymmetries which are predicted to vanish in the standard model or by comparing two measurements which are predicted to be equal in the standard model. In particular, we show that the measurement of the CKM angle γ\gamma in electroweak penguin dominated processes Bs0ρ0η(),ρ0ϕB_s^0\to\rho^0\eta^{(')}, \rho^0\phi can largely be affected by the new physics.Comment: References and discussion added, version to be published in PR

    Collider aspects of flavour physics at high Q

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    This review presents flavour related issues in the production and decays of heavy states at LHC, both from the experimental side and from the theoretical side. We review top quark physics and discuss flavour aspects of several extensions of the Standard Model, such as supersymmetry, little Higgs model or models with extra dimensions. This includes discovery aspects as well as measurement of several properties of these heavy states. We also present public available computational tools related to this topic.Comment: Report of Working Group 1 of the CERN Workshop ``Flavour in the era of the LHC'', Geneva, Switzerland, November 2005 -- March 200

    Modeling mango fruit and vegetative growth

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    Die gezielte Freisetzung genetisch veraenderter Organismen Oekologische Ueberlegungen und Empfehlungen

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    Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLE2. ed.DEGerman

    Desenvolvimento dos frutos de pêssego 'Aurora' e nectarina 'Sunraycer' no sul de Santa Catarina

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    O desenvolvimento do fruto de pessegueiro é resultado da diferenciação e do crescimento das paredes do ovário após a fecundação. A persistência e o crescimento do fruto na planta dependem das relações exatas entre os hormônios auxina, giberelina e citocinina que condicionam o desenvolvimento dos frutos, caracterizado por uma curva dupla sigmoide, com três estádios distintos. O presente trabalho teve por objetivo conhecer o comportamento dos frutos e das sementes do pêssego Aurora e da Nectarina Sunraycer durante todo o seu ciclo de desenvolvimento. O crescimento dos frutos e das sementes durante o ciclo foi determinado semanalmente, coletando-se 30 frutos de dez diferentes plantas em ramos previamente identificados. As sementes foram separadas do fruto para a determinação do peso fresco (PF) e do peso seco (PS). O crescimento dos frutos da variedade Sunraycer dá-se de forma contínua e acelerada desde a floração até a maturação, sugerindo um curto período ou a inexistência do Estágio II de crescimento. Para a variedade Aurora, a curva de crescimento é diferenciada nos três estádios (I, II e III). O raleio dos frutos deve ser feito até o início do estádio II, para a variedade Aurora e Sunraycer. As sementes das variedades Aurora e Sunraycer atingem seu tamanho máximo no estágio I de crescimento do fruto. O aumento de peso seco na semente, para a variedade Sunraycer, é praticamente inexistente no estádio III, enquanto para a variedade Aurora ocorre o maior aumento de peso seco que vai até a maturação do fruto
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