43 research outputs found

    Differential Equations arising from Organising Principles in Biology

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    This workshop brought together experts in modeling and analysis of organising principles of multiscale biological systems such as cell assemblies, tissues and populations. We focused on questions arising in systems biology and medicine which are related to emergence, function and control of spatial and inter-individual heterogeneity in population dynamics. There were three main areas represented of differential equation models in mathematical biology. The first area involved the mathematical description of structured populations. The second area concerned invasion, pattern formation and collective dynamics. The third area treated the evolution and adaptation of populations, following the Darwinian paradigm. These problems led to differential equations, which frequently are non-trivial extensions of classical problems. The examples included but were not limited to transport-type equations with nonlocal boundary conditions, mixed ODE-reaction-diffusion models, nonlocal diffusion and cross-diffusion problems or kinetic equations

    Analysis of toxic effects and nutrient stress in aquatic ecosystems

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    Kooijman, S.A.L.M. [Promotor]Kooi, B.W. [Copromotor

    Coevolution of dispersal-related traits : modelling and analysis

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    This thesis theoretically investigates dispersal evolution in a wider ecological context. It factors in ecological relevant dependencies e.g. trade-offs or spatial heterogeneity, and allows coevolutionary interactions between immigration and other traits. It extends well-known models to include more biological realism, reveals novel evolutionary mechanisms and helps to understand the complex dispersal patterns more accurately. In particular, this work studies the evolution of dispersal, i.e., natal emigration when it is under a trade-off with fecundity. Furthermore, dispersal is divided into its three phases and hence studied as emigration, transfer and immigration. Emigration and immigration are made dependent on the local conditions experienced by the individuals: the patch types. The coevolution of patch-type dependent immigration is investigated alone, but also the coevolution of patch-type dependent immigration and patch-type dependent emigration or local adaptation is studied. The evolutionary framework was chosen to be adaptive dynamics, a way of describing the long-term evolutionary outcomes of single populations that can lead to evolutionary diversification of strategies

    Bifurcation analysis of the Topp model

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    In this paper, we study the 3-dimensional Topp model for the dynamicsof diabetes. We show that for suitable parameter values an equilibrium of this modelbifurcates through a Hopf-saddle-node bifurcation. Numerical analysis suggests thatnear this point Shilnikov homoclinic orbits exist. In addition, chaotic attractors arisethrough period doubling cascades of limit cycles.Keywords Dynamics of diabetes 路 Topp model 路 Reduced planar quartic Toppsystem 路 Singular point 路 Limit cycle 路 Hopf-saddle-node bifurcation 路 Perioddoubling bifurcation 路 Shilnikov homoclinic orbit 路 Chao

    Dynamical Systems

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    Complex systems are pervasive in many areas of science integrated in our daily lives. Examples include financial markets, highway transportation networks, telecommunication networks, world and country economies, social networks, immunological systems, living organisms, computational systems and electrical and mechanical structures. Complex systems are often composed of a large number of interconnected and interacting entities, exhibiting much richer global scale dynamics than the properties and behavior of individual entities. Complex systems are studied in many areas of natural sciences, social sciences, engineering and mathematical sciences. This special issue therefore intends to contribute towards the dissemination of the multifaceted concepts in accepted use by the scientific community. We hope readers enjoy this pertinent selection of papers which represents relevant examples of the state of the art in present day research. [...

    Topology Reconstruction of Dynamical Networks via Constrained Lyapunov Equations

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    The network structure (or topology) of a dynamical network is often unavailable or uncertain. Hence, we consider the problem of network reconstruction. Network reconstruction aims at inferring the topology of a dynamical network using measurements obtained from the network. In this technical note we define the notion of solvability of the network reconstruction problem. Subsequently, we provide necessary and sufficient conditions under which the network reconstruction problem is solvable. Finally, using constrained Lyapunov equations, we establish novel network reconstruction algorithms, applicable to general dynamical networks. We also provide specialized algorithms for specific network dynamics, such as the well-known consensus and adjacency dynamics.Comment: 8 page

    Book of abstracts

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    MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

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    Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described

    Generalized averaged Gaussian quadrature and applications

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    A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal
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