uk: Математика, природничі науки

uk: вхід без авторизації

name: Compactness of sign-changing solutions to scalar curvature-type equations with bounded negative part.


Gabriella Tarantello

type: Person

cs: Matematika

de: Mathematik

fi: matematiikka

uk: Математика

en: Mathematics

fr: Mathématiques

da: Matematik

es: Matemáticas

nl: Wiskunde

de: Mathematik, Naturwissenschaften

uk: Математика, природничі науки

en: Mathematics, Natural Sciences

TIB AV-Portal

type: Service

type: WebContent

type: MediaObject

@language: en

cs: přihlášení není vyžadováno

de: keine Anmeldung erforderlich

uk: вхід без авторизації

en: no login required

nl: geen login vereist

name: Minimal immersions of closed surfaces in hyperbolic 3-manifold.

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery

type: Organization

cs: Video

de: Video

fi: Video

uk: Відео

en: Video

fr: Vidéo

da: Video

nl: Video

es: Video


uk: Математика, природничі науки

uk: вхід без авторизації

name: Infinite-time bubbling in the critical nonlinear heat equations


uk: Математика, природничі науки

uk: вхід без авторизації

name: Topological and variational methods for the supercritical Moser-Trudinger equation.


uk: Математика, природничі науки

uk: вхід без авторизації

name: A compactness theorem of the fractional Yamabe problem.


uk: Математика, природничі науки

uk: вхід без авторизації

name: Hardy-Sobolev operator with boundary singularity: stability of the Pohozaev obstruction


uk: Математика, природничі науки

uk: вхід без авторизації

name: The non-local mean-field equation on an interval.


uk: Математика, природничі науки

uk: вхід без авторизації

name: Uniqueness and non-degeneracy of bubbling solutions for Liouville equations.


uk: Математика, природничі науки

uk: вхід без авторизації

name: The Poisson equation on Riemannian manifolds with a weighted Poincaré inequality at infinity.


uk: Математика, природничі науки

uk: вхід без авторизації

name: Supercritical problems on the round sphere and the Yamabe problem in projective spaces.


uk: Математика, природничі науки

uk: вхід без авторизації

name: Liouville type theorems and local behaviour of solutions to degenerate or singular problems.


uk: Математика, природничі науки

uk: вхід без авторизації

name: Influence of the scalar curvature and the mass on blowing-up solutions to low-dimensional conformally invariant equations.


uk: Математика, природничі науки

uk: вхід без авторизації

name: Nonlocal ODE, conformal geometry and applications.


Log-determinants in conformal geometry.

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: A double mean field approach for a curvature prescription problem.


uk: Математика, природничі науки

uk: вхід без авторизації

name: A spinorial analogue of the Brezis-Nirenberg theorem.


cs: Informatika

de: Informatik

fi: tietojenkäsittelytiede

uk: Комп'ютерні науки

en: Computer Science

fr: Informatique

da: Datalogi

es: Ciencias de la Computación

nl: Informatica

uk: Бібліотекознавство, документознавство

en: Information and Library Sciences

de: Geisteswissenschaften

uk: Гуманітарні науки

en: Humanities

cs: Technické vědy

de: Ingenieurwissenschaften

fi: tekniikka

uk: Інженерія

en: Engineering Sciences

fr: Ingénierie

da: Ingeniørvidenskab

es: Ingeniería

nl: Engineering

@language: de

uk: вхід без авторизації

name: re3data COREF - Ausbau und Weiterentwicklung des Registry of Research Data Repositories

name: Verein Deutscher Bibliothekarinnen und Bibliothekare e. V. (VDB)

name: Berufsverband Information Bibliothek e. V. (BIB)


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

uk: вхід без авторизації

name: Forschungsdatenrepositorium mit einem kooperativen Betriebsmodell: Fallstudie


uk: Математика, природничі науки

description: We will begin by defining the rank of an affine invariant submanifold in a stratum of abelian differentials on genus g surfaces. We will end by showing that if the rank is at least g/2 + 1 then the affine invariant submanifold is either the full component of the stratum containing it or a holonomy double cover of a component of a stratum of quadratic differentials. This is joint work with Alex Wright.

uk: вхід без авторизації

name: If an orbit closure is big enough then it's trivial.

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

uk: вхід без авторизації

name: Classification of proper non arithmetic affine manifolds in H(2,2)^{odd} and H(3,1)


uk: Математика, природничі науки

description: A collection of polygons with the property that to each side one can find another side parallel to it can be endowed with a translation surface structure by glueing along those edges. This means that the closed surfaces obtained carries a flat metric outside finitely many conical singularities. Geodesics (which are straight lines) connecting such singularities are called saddle connections. While the asymptotic number of saddle connections of length less then T growth roughly like T^2 (in the sense that there are lower and upper bounds of that order), one can say more for a generic surface with respect to the moduli space of such structures thanks to the natural SL2-action it is equipped with. I shall present some results with polynomial error saving for counting saddle connections in the setting of a) general loci (j/w Nevo,Weiss) b) prescribed congruence restrictions in homology (j/w Magee, Guetierrez-Romo) c) lattice-surfaces using Eisenstein series (j/w Burrin,Nevo,Weiss)

uk: вхід без авторизації

name: Counting Saddle Connection on Translation surfaces.


uk: Математика, природничі науки

description: A group acting on an elliptic curve must have order N = 1, 2, 3, 4, or 6. We call the quotient an elliptic orbifold. Certain branched covers of the order N elliptic orbifold are in bijection with tiled surfaces, and form a lattice in the moduli space of N-ic differentials on Riemann surfaces. The enumerative theory of these branched covers suggests a phantom "elliptic orbifold" for all integers N. I will discuss work-in-progress with Peter Smillie proposing a definition for the Hurwitz theory of this non-existent object, and attempts to relate it to quasi-crystals in the moduli space of quintic differentials and the enumeration of Penrose-tiled Riemann surfaces. From the minute 31:11 of video does not have audio.

uk: вхід без авторизації

name: Penrose tilings and Hurwitz theory of leaf spaces


uk: Математика, природничі науки

uk: вхід без авторизації

name: Towards the Euler characteristic of strata


uk: Математика, природничі науки

description: Let X be a closed, connected, hyperbolic surface of genus 2. Is it more likely for a simple closed geodesic on X to be separating or non-separating? How much more likely? In her thesis, Mirzakhani gave very precise answers to these questions. One can ask analogous questions for square-tiled surfaces of genus 2 with one horizontal cylinder. Is it more likely for such a square-tiled surface to have separating or non-separating horizontal core curve? How much more likely? Recently, Delecroix, Goujard, Zograf, and Zorich gave very precise answers to these questions. Surprisingly enough, their answers were exactly the same as the ones in Mirzakhani’s work. In this talk we explore the connections between these counting problems, showing they are related by more than just an accidental coincidence.

uk: вхід без авторизації

name: Counting square-tiled surfaces with prescribed real and imaginary foliations


uk: Математика, природничі науки

description: Kontsevich and Zorich famously classified the connected components of strata of translation surfaces over moduli space. The corresponding problem over the Teichmüller space requires the analysis of which mapping classes can be realized as deformations lying inside the stratum. In this talk, I will present joint work with Nick Salter in which we classify the (non-hyperelliptic) connected components of strata over Teichmüller space. Unlike the case for strata over moduli space, we find that there can be many (but finitely many) connected components, depending on both genus and cone angle.

uk: вхід без авторизації

name: Translation surfaces, higher spin structures, and the mapping class group


uk: Математика, природничі науки

description: An IET is rational if it translates points by rational amount. In a finite rational IET, all orbits are periodic. In an infinite IETs, this need not be the case. I will discuss some examples of infinite rational IETs in which it can be proved that almost every point is periodic. Further the dynamics on the aperiodic sets can be completely understood. Theory developed to understand these examples points out an interesting class of infinite IETs admitting a renormalization scheme (though it remains to be seen how effective this scheme is for understanding generic IETs). I will be discussing a preprint joint with Kasra Rafi and Anja Randecker, and a work in progress joint with Anna Tao.

uk: вхід без авторизації

name: Renormalization in some infinite rational IETs


uk: Математика, природничі науки

description: The Gauss circle problem consists in counting the number of integer points of bounded length in the plane. This problem is equivalent to counting the number of closed geodesics of bounded length on a flat two dimensional torus. Many counting problems in dynamical systems have been inspired by this problem. For 30 years, the experts try to understand the asymptotic behavior of closed geodesics in translation surfaces and periodic trajectories on rational billiards. (Polygonal billiards yield translation surfaces naturally through an unfolding procedure.) H. Masur proved that this number has quadratic growth rate. In this talk, we will study the counting problem on infinite periodic rational billiards and translation surfaces. The first example and motivation is the wind-tree model, a Z^2-periodic billiard model. In the classical setting, we place identical rectangular obstacles in the plane at each integer point; we play billiard on the complement. It is possible to give quite precise results on the counting problem for this model, thanks to the many symmetries it presents. These results, however, do not extend to more general contexts. I will present a general result on the counting problem for infinite periodic translation surfaces that uses new ideas: a dynamical analogous, for the algebraic hull of a cocycle, to strong and super-strong approximation on algebraic groups. Under these approximation hypothesis I will exhibit asymptotic formulas for the number of closed geodesics of bounded length on infinite periodic translation surfaces. And will present some applications and discuss why I think these hypothesis hold in general (work in progress).

uk: вхід без авторизації

name: Asymptotic formulas on infinite periodic translation surfaces.


uk: Математика, природничі науки

description: When geometric structures on surfaces are determined by the lengths of curves, it is natural to ask which curves’ lengths do we really need to know? It is a classical result of Fricke that a hyperbolic metric on a surface is determined by its marked simple length spectrum. More recently, Duchin–Leininger–Rafi proved that a flat metric induced by a unit-norm quadratic differential is also determined by its marked simple length spectrum. In this talk, I will describe a generalization of the notion of simple curves to that of q-simple curves, for any positive integer q, and show that the lengths of q-simple curves suffice to determine a non-positively curved Euclidean cone metric induced by a q-differential metric.

uk: вхід без авторизації

name: Spectral Rigidity of q-differential Metrics


uk: Математика, природничі науки

description: There is a natural forgetful map p from a stratum H of abelian differentials to the moduli space of Riemann surfaces that takes a pair (X,w) to X. What are the coarse properties of this map p? In particular, when is the image coarsely dense with respect to the Teichmuller metric on moduli space? We answer this question for all strata by showing that the projection is coarsely dense iff it is topologically dense. The proof uses a new compactification of strata due to Bainbridge-Chen-Gendron-Grushevsky-Moller. This is joint work with Jenya Sapir.

uk: вхід без авторизації

name: Coarse density of projection of strata to moduli space


Symbolic coding Euclidean billiards.

uk: Математика, природничі науки

description: In this talk I'll explain how the shape of a Euclidean polygon is essentially determined by the symbolic coding of the "generalized diagonal" billiard trajectories. The bulk of the talk will involve the reduction of this theorem to a rigidity result for flat surfaces. This is joint work with Moon Duchin, Viveka Erlandsson, and Chandrika Sadanand.

uk: вхід без авторизації


Random walk on simplicial complexes

uk: Математика, природничі науки

description: We generalize random walks on graphs to random walks on simplicial complexes, also called hypergraphs, using some notions of topological algebra. The transition matrix of this RW is related to the higher order Laplacian which is the generalization of graph Laplacian. We also analyze the limit behavior of this RW when the number of points in the simplicial complex tends to infinity.

uk: вхід без авторизації


uk: Математика, природничі науки

description: We discuss critical behavior of percolation on finite random networks. In a seminal paper, Aldous (1997) identified the scaling limit for the component sizes in the critical window of phase transition for the Erdos-Renyi random graph (ERRG). Subsequently, there has been a surge in the literature, revealing several interesting scaling limits of these critical components, namely, the component size, diameter, or the component itself when viewed as a metric space. Fascinatingly, when the third moment of the asymptotic degree distribution is finite, many random graph models have been shown to exhibit a universality phenomenon in the sense that their scaling exponents and limit laws are the same as the ERRG. In contrast, when the asymptotic degree distribution is heavy-tailed (having an infinite third moment), the limit law turns out to be fundamentally different from the ERRG case and in particular, becomes sensitive to the precise asymptotics of the highest degree vertices. In this talk, we will focus on random graphs with a prescribed degree sequence. We start by discussing recent scaling limit results, and explore the universality classes that arise from heavy-tailed networks. Of particular interest is a new universality class that arises when the asymptotic degree distribution has an infinite second moment. Not only it gives rise to a completely new universality class, it also exhibits several surprising features that have never been observed in any other universality class so far. This is based on joint works with Shankar Bhamidi, Remco van der Hofstad, Johan van Leeuwaarden and Sanchayan Sen.

uk: вхід без авторизації

name: Critical percolation on networks with given degrees


uk: Математика, природничі науки

description: The ferromagnetic Ising model is a paradigmatic model of statistical physics used to study phase transitions in lattice systems. In this talk I shall consider the setting where the regular spatial structure is replaced by a random graph, which is often used to model complex networks. I shall treat both the case where the graph is essentially frozen (quenched setting) and the case where instead it is rapidly changing (annealed setting). I shall prove that quenched and annealed may have different critical temperatures, provided the graph has sufficient inhomogeneity. I shall also discuss how universal results (law of large numbers, central limit theorems, critical exponents) are affected by the disorder in the spatial structure. The picture that I will present emerges from several joint works, involving V.H. Can, S. Dommers, C. Giberti, R.van der Hofstad and M.L.Prioriello.

uk: вхід без авторизації

name: Quenched and annealed Ising models on random graphs


uk: Математика, природничі науки

description: The main object of study in this paper is an epidemic process on a large network in the presence of various public health interventions. As an example, we consider a simple Susceptible-Infected (SI)-type epidemic process on a Configuration Model (CM) random graph with public health interventions in the form of active random surveillance and contact-tracing. While infected individuals attempt to infect their neighbours, they themselves are at risk of removal due to random surveillance and contact-tracing. We allow the random graph to be constructed dynamically as an outcome of the spread of infection and removal due to contact-tracing. We study the large graph limit of these two competing processes (infection and contact-tracing) as the number of vertices grows to infinity. From the public health perspective, the large graph limit can be utilized to determine the optimal rates for surveillance and contact-tracing given a fixed budget constraint by formulating a suitable optimal control problem. Joint work with Soheil Eshghi, Eben Kenah, Forrest W. Crawford and Grzegorz A. Rempała.

uk: вхід без авторизації

name: Surveillance versus contact-tracing on configuration model graphs


uk: Математика, природничі науки

description: A common goal in the domain of systems and synthetic biology is to understand the relationship between design and function of gene regulatory networks. This is a significant challenge for several reasons. Typically understanding the behavior of a gene regulatory network means understanding the associated dynamics. Traditionally this requires having an acceptable nonlinear model, knowledge of parameter values, and knowledge of initial conditions, all of which are difficult to obtain in the setting of complex multi-scale problems. To circumvent these challenges we have developed a novel approach to nonlinear dynamics based on order theory and algebraic topology. This method allows for efficient computations of rigorous combinatorial/algebraic topological descriptions of the global dynamics over large ranges of parameter space. As a consequence, given a regulatory network, we are able to construct a database describing all the associated dynamics. I will discuss the theory behind this tool and demonstrate how it can be applied to specific examples.

uk: вхід без авторизації

name: The DSGRN Database for Dynamics of Gene Regulatory Networks


uk: Математика, природничі науки

description: Consider a system of N parallel single-server queues with unit-exponential service time distribution and a single dispatcher where tasks arrive as a Poisson process of rate l(N). When a task arrives, the dispatcher assigns it to one of the servers according to the Join-the-Shortest Queue (JSQ) policy. Eschenfeldt and Gamarnik (2015) established that appropriately scaled functionals of the queueing network under the JSQ policy converge weakly to associated functionals for a certain non-elliptic reflected diffusion process as N grows. I will talk about analyzing the detailed behavior of the steady state of this non-standard diffusion process using tools from renewal theory. The tails and bulk behavior of the steady state distribution and sample path fluctuations of the diffusion process will be explored. We will also see how the steady state shows a stark difference in behavior between two regimes governed by a system parameter. This is joint work with Debankur Mukherjee.

uk: вхід без авторизації

name: Joining the shortest queue, non-elliptic reflected diffusions and stationarity


uk: Математика, природничі науки

description: I will discuss a class of random spatial networks and show that they have small world-like properties, but the level of clustering is tunable and we can make it arbitrarily small. In some limits we are able to derive a system of integro-differential equations which allows us to accurately predict both the temporal and spatial dynamics of SIR disease. We can use these equations to determine when the network behaves like a small world network with significant long-range transmissions and when the dynamics are dominated by the short-range transmission. Interestingly, we show that the "small-world" properties of disease spread can exist even in the limit of no clustering, and thus the concept of a small-world network is determined more by whether the network has a combination of short-range and long-range connections than whether the network has many clustered connections.

uk: вхід без авторизації

name: Contagion spread in clustered and unclustered small world networks


uk: Математика, природничі науки

description: As highlighted in a recent perspective article (Science 359:738, 2018), in ecology, exact predictions are extremely challenging. In the presentation, we ask how do species evolve in environments with asymmetric fluctuating temperature profiles. We study how natural selection do not lead to adaption to the mean temperature but to a value that is shifted and given by the skewness of the temperature profile. This prediction is derived from first principles and first results are presented in nematodes. More generally, we discuss effects from ergodicity breaking for evolutionary game theory (Stollmeier & Nagler, Phys. Rev. Lett. 120:058101, 2018), coupled ecosystems and for climate change. In the final part, we ask how to beat seemingly universally optimal strategies (Extortion Zero Determinant Strategies) and how seemingly unresolvable conflicts (such as Prisoner's dilemmas) can be resolved in complex noisy environments and how does machine intelligence (Timme & Nagler, Nature Phys. 15:308, 2019) helps in noisy systems.

uk: вхід без авторизації

name: Population growth, ergodicity breaking and optimal stategies in ecosystems and games

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: I will present comparisons between large-scale stochastic simulations and mean-field theories for the epidemic thresholds and prevalence of the susceptible-infected-susceptible (SIS) model on networks with power-law degree distributions and degree correlations. We confirm the vanishing of the threshold regardless of the correlation pattern and degree exponent. The thresholds are compared with heterogeneous mean-field (HMF), quenched mean-field (QMF) and pair quenched mean-field (PQMF) theories where the degree correlation patterns are explicitly considered. The PQMF, which additionally reckons dynamical correlations, outperforms the other two theories and its level of quantitative success depends on the type of degree correlation (assortative, disassortative or uncorrelated). Furthermore, we observe a strong correlation between the success of PQMF theory and the properties of the principal eigenvector such as the inverse participation ration (IPR) and the spectral gap. If the IPR is large and tends to a finite value at the limit of large networks the PQMF predictions deviate from numerical simulations. Otherwise, if the IPR is small, PQMF theory shows an excellent match with the simulations. Finally, the epidemic prevalence near to the critical point and the corresponding critical exponents are compared with both QMF theory and exact results.

uk: вхід без авторизації

name: Eigenvector localization, dynamical correlations and epidemic thresholds on random networks with degree correlations


uk: Математика, природничі науки

description: Consider a large community, structured as a network, in which an epidemic spreads. Infectious individuals spread the disease to each of their susceptible neighbors, independently, at rate λ, and each infectious individual recovers and becomes immune at rate γ. The social distancing is modeled by each susceptible who has an infectious neighbor rewires away this individual to a randomly chosen individual at rate ω. Our main result is surprising and says: the rewiring is rational from an individual perspective in that it reduces the risk of being infected, but at the same time it may be harmful for the community at large since the outbreak may get bigger compared to no rewiring (ω=0).

uk: вхід без авторизації

name: Epidemics in structured communities with social distancing


Epidemic Spread on Networks

uk: Математика, природничі науки

description: Epidemic models are increasingly applied in real-world networks to understand various kinds of diffusion phenomena (such as the spread of diseases, emotions, innovations, failures) or the transport of information (such as news, memes in social on-line networks and activity in functional human brain networks). We will mainly focus on Susceptible-Infected-Susceptible (SIS) epidemics on networks. We believe that the SIS Markovian epidemics on a given, fixed graph is one of the simplest "local rule - global emergence" models that allows a remarkable level of analysis. After a brief review of the SIS continuous-time Markovian process on a graph, we will show why SIS epidemics on networks are so interesting and we will overview our recent developments.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In a recent paper KhudaBukhsh et al., we showed that solutions to Ordinary Differential Equations (ODEs) describing the large-population limits of Markovian stochastic compartmental dynamical systems can be interpreted as survival or hazard functions when analyzing data from individuals sampled from the population. An earlier paper by Kenah showed that likelihoods from individual-level mass-action transmission models simplify in the limit of a large population when the depletion of susceptibles is negligible. In this paper, we unify and generalize these results by deriving population-level survival and hazard functions from explicit individual-level models. This allows population-level survival analysis to be applied to a more general class of epidemic models and allows the asymptotic pairwise likelihoods to be applied throughout the course of an epidemic. In practice, this will provide a logically consistent framework for the analysis of both high-resolution outbreak investigations or household studies and population-level surveillance or sentinel data.

uk: вхід без авторизації

name: Survival Dynamical Systems: Individual-level survival analysis from population-level transmission models


The Contact Process with Avoidance

uk: Математика, природничі науки

description: The (classical) contact process is a stochastic process on the vertices of a graph, which is a discrete, spatial model for the spread of a disease. The state of the contact process at time t is given by an infected subset of the vertices of the graph. At rate 1, each infected vertex becomes healthy, and therefore susceptible to reinfection. At rate lambda>0, each edge between an infected vertex and a healthy vertex transmits the infection, thus infecting the healthy vertex. The contact process has been thoroughly analyzed on the integer lattices and regular trees, where it is well-known to exhibit a phase transition: for large lambda, epidemics persist, while for smaller lambda, all vertices are eventually healthy. More recently, researchers have made progress in analyzing the behavior of the contact process on (finite) complex networks, where epidemics may persist for all lambda>0 on graphs with `heavy-tailed' degree distributions. I will discuss recent progress on a version of the contact process in which the edges of the graph are also dynamic: at rate alpha, each edge from an infected vertex to a healthy vertex will deactivate; the edge will become active again when the infected vertex becomes healthy, and only active edges can transmit the infection. This emulates avoidance of infected individuals by healthy individuals. We demonstrate that the long-time qualitative behavior of this model may or may not differ from the classical contact process, depending on the underlying network topology. A technical obstacle is the lack of a certain type of monotonicity, which is present for the classical model. Based on joint work with Shirshendu Chatterjee and Matthew Wascher.

uk: вхід без авторизації


uk: Математика, природничі науки

description: The process we consider are voter model perturbations in the sense of Cox, Durrett, and Perkins. We will describe results for two examples: evolutionary games with weak selection and the latent voter model in which individuals who adopt a new technology (e.g. buy an iPhone) have a latent period in which they will not change their state. These examples were analyzed in joint work with Ted Cox (EG) and Ran Huo (LVM). The relevant papers are 179, 202 and 203 on my web page.

uk: вхід без авторизації

name: ODE limits for particle systems on graphs


uk: Математика, природничі науки

description: Stochastic models of populations have a long history beginning with branching processes and continuing with models in population genetics and models of the spatial distribution of populations. At the same time, models of population genealogies were developed in the population genetics literature. Work with Peter Donnelly (1999) showed how to simultaneously construct models that include both the forward in time evolution of the population distribution and the backward in time genealogy starting at any time point in the forward in time evolution. These "lookdown" constructions were essentially restricted to neutral models, that is, models in which birth rates, offspring distributions, and death rates do not depend on the types or locations of the individuals in the population. Following some earlier preliminary results, work with Eliane Rodrigues (2011) gave lookdown constructions for general Markov branching processes in which the birth rates, offspring distributions, and death rates can depend on the location/type of the individual. Extension of these lookdown/genealogical constructions to very general Markov population models, to appear in a forthcoming paper with Alison Etheridge, will be discussed.

uk: вхід без авторизації

name: Genealogies for stochastic population models


uk: Математика, природничі науки

description: The idea of a survival dynamical system (SDS) is to apply aggregated dynamics of a macro model at the level of an individual agent. SDS may be also viewed a limit of agents’ dynamics obtained when replacing individual’s random hazard function with its large volume limit. Under this second interpretation it is relatively simple to obtain an extension of the classical mass-action SDS to a configuration model random graph and to provide some basic results allowing for estimating the underlying epidemic parameters from micro-level data. As it turns out, in a certain class of degree distributions the SDS model takes a particularly simple from and its statistical analysis is only moderately more complicated than the classical mass-action SDS as given by the standard SIR equations.

uk: вхід без авторизації

name: Survival Dynamical Systems on Random Graphs


uk: Математика, природничі науки

description: The theory of large deviations gives decay rates of probabilities of rare events in terms of certain optimal control problems. In general these control problems do not admit simple form solutions and one needs numerical methods in order to obtain useful information. In this talk I will present some large deviation problems where one can use methods of calculus of variations to give explicit solutions to the associated optimal control problems. These solutions then yield explicit asymptotic formulas for probability decay rates in several settings. The case of the Configuration Model will be discussed in detail.

uk: вхід без авторизації

name: On Some Calculus of Variations Problems for Rare Event Asymptotics


uk: Математика, природничі науки

description: Very large networks linking dynamical agents are now ubiquitous and there is significant interest in their analysis, design and control. The emergence of the graphon theory of large networks and their infinite limits has recently enabled the formulation of a theory of the centralized control of dynamical systems distributed on asymptotically infinite networks [Gao and Caines, IEEE CDC 2017, 2018]. Furthermore, the study of the decentralized control of such systems has been initiated in [Caines and Huang, IEEE CDC 2018] where Graphon Mean Field Games (GMFG) and the GMFG equations are formulated for the analysis of non-cooperative dynamical games on unbounded networks. In this talk the GMFG framework will be first be presented followed by the basic existence and uniqueness results for the GMFG equations, together with an epsilon-Nash theorem relating the infinite population equilibria on infinite networks to that of finite population equilibria on finite networks.

uk: вхід без авторизації

name: Mean Field Games on Unbounded Networks and the Graphon MFG Equations


uk: Математика, природничі науки

description: Seemingly trivial modifications to the classical model of contagion spreading can dramatically alter its phenomenology. For example, discontinuous phase transitions can occur due to complex or interacting contagions, accelerating transmission and hysteresis loops can occur when individuals modify their behaviour after becoming infectious, and double phase transitions can emerge in the presence of asymmetric percolation. In this talk, I will present recent theoretical work on the affect of behaviour on contagion spreading and discuss empirical support for these new models. Our findings demonstrate the inherent complexity of biological contagion and we anticipate that our methods will advance the emerging field of disease forecasting.

uk: вхід без авторизації

name: Behaviour-induced phase transitions in contagion models on networks


uk: Математика, природничі науки

description: The Gross-Pitaevskii (GP) equation is named after Eugene P. Gross and Lev P. Pitaevskii who introduced it independently in 1961 for the purpose of describing vortices in superfluids. At that time the only known superfluid was liquid helium, but since the first experimental realization of Bose-Einstein condensates in trapped gases of alkali atoms in 1995 the GP equation has become a basic tool for theoretical investigations of the manifold quantum phenomena exhibited by dilute, ultracold Bose gases. Mathematically, the GP equation is a special case of a non-linear Schrödinger equation and the mathematics and physics literature about it is vast. In the talk the focus will be on the following topics: 1) The interpretation of the equation on the basis of many-body quantum mechanics. 2) Vortices in rapidly rotating trapped superfluids at strong coupling and the determination of critical speeds that mark phase transitions from single vortices to a vortex lattice pattern and finally to a giant vortex.

uk: вхід без авторизації

name: The Gross-Pitaevskii Equation and Quantum Vortices


uk: Математика, природничі науки

description: Landau-Lifshitz equations are the basic dynamical equations in a micromagnetic description of a ferromagnet. They are naturally viewed as geometric evolution PDE of dispersive, Hamiltonian type (Schrödinger maps") , which scale critically with respect to the physical energy in two space dimensions. We describe here recent results on the stability of important topological soliton solutions known as ``chiral magnetic skyrmions".

uk: вхід без авторизації

name: Stability of chiral magnetic skyrmions for 2D Landau-Lifshitz equations


uk: Математика, природничі науки

description: Considering general classes of nonlinear Schrödinger equations on the circle with nontrivial cubic part and without external parameters, I will present the construction a new type of normal forms, namely rational normal forms, on open sets surrounding the origin in high Sobolev regularity. With this new tool we prove that, given a large constant M and a sufficiently small parameter \varepsilon$, for generic initial data of size \varepsilon, the flow is conjugated to an integrable flow up to an arbitrary small remainder of order \varepsilon^{M+1}. This implies that for such initial data u(0) we control the Sobolev norm of the solution u(t) for time of order \varepsilon^{-M}. Furthermore this property is locally stable: if v(0) is sufficiently close to u(0) (of order \varepsilon^{3/2}) then the solution v(t) is also controled for time of order $\varepsilon^{-M}. This is a joint work with Erwan Faou and Benoît Grébert.

uk: вхід без авторизації

name: Rational normal forms and stability of small solutions to nonlinear Schrödinger equations


uk: Математика, природничі науки

description: In the talk I will present some recent results on upper and lower bounds for the growth of Sobolev norms in linear time dependent Schrödinger equations. After discussing the known upper bounds on the Sobolev norms of the solutions, I will explain a strategy to construct time dependent perturbations which provoke transfer of energy from low to high modes, leading to unbounded solutions.

uk: вхід без авторизації

name: Growth of Sobolev norms for abstract linear Schrödinger equations


uk: Математика, природничі науки

description: Steady states in Hamiltonian PDEs are often constrained minimizers of energy subject to fixed mass and momentum. I will discuss two examples when the minimizers are degenerate so that spectral stability of minimizers does not imply their nonlinear stability due to lack of coercivity of the second variation of energy. For the example related to the conformally invariant cubic wave equation on three-sphere, we prove that integrability of the normal form equations results in nonlinear stability of steady states. For the other example related to the nonlinear Schrodinger equation on a star graph, we prove that the lack of momentum conservation results in the irreversible drift of steady states and their nonlinear instability.

uk: вхід без авторизації

name: Drift of steady states in Hamiltonian PDEs: two examples


uk: Математика, природничі науки

uk: вхід без авторизації

name: Dynamical System Approach to Spectral Theory of Quasi-Periodic Schrödinger operators


General introduction to "KAM for PDEs"

uk: Математика, природничі науки

description: It is well known that the phase space of a finite dimensional integrable system is filled by invariant tori; KAM theory ensures that most of them persist under small perturbation. In PDEs the situation is much more complicated, and the only quite complete theory that we know, allows to deal with Hamiltonian PDEs in one space dimension and only allows to show persistence of finite dimensional tori. A few eamples in higher dimensions are also known. Also some preliminary results on the persistence of infinite dimensional tori are known. In this talk I will present some of the above results and discuss some open problems related to the possible application to Gross Pitaevskii equation.

uk: вхід без авторизації


uk: Математика, природничі науки

description: We study the issue of collisions in finite time for vortex filaments in 3D incompressible fluids, according to a model introduced by Klein, Majda and Damodaran. We also mention another more precise model for the dynamics of one filament introduced by Zhakarov. This is joint work with Valeria Banica and Erwan Faou.

uk: вхід без авторизації

name: Dynamics and collisions of nearly parallel vortex filaments


uk: Математика, природничі науки

description: We consider the NLS equation with focusing nonlinearities in a presence of an external field. We investigate the soliton motions that correspond to a free soliton escaping the well created by the potential. We exhibit the dynamical system driving the exiting trajectory and construct the associated nonlinear dynamics for untrapped motions.

uk: вхід без авторизації

name: Solitons of the NLS equation escaping a potential.

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: We consider the defocusing cubic nonlinear Schrödinger equation (NLS) on the two-dimensional torus. This equation admits a special family of elliptic invariant quasiperiodic tori called finite-gap solutions. These solutions are inherited from the integrable 1D model (cubic NLS on the circle) by considering solutions that depend only on one variable. We study the long-time stability of such invariant tori for the 2D NLS model and show that, under certain assumptions and over sufficiently long timescales, they exhibit a strong form of transverse instability in Sobolev spaces H^s(T^2) (0 < s < 1). More precisely, we construct solutions of the 2D cubic NLS that start arbitrarily close to such invariant tori in the H^s topology and whose H^s norm can grow by any given factor. In my talk, I will also say some words about the ongoing work concerning Sobolev instability of more general 2D quasi-periodic solutions. The subject of this talk is partly motivated by the problem of infinite energy cascade for 2D NLS, and it is a joint work with M. Guardia, Z. Hani, A. Maspero and M. Procesi.

uk: вхід без авторизації

name: Strong Sobolev instability of quasi-periodic solutions of the 2D cubic Schrödinger equation


uk: Математика, природничі науки

description: In this talk I will present a reducibility result holding for time quasi-periodic unbounded perturbations of a non-resonant transport equation on the d−dimensional torus $T^d$ . Such a result is obtained combining pseudo-differential calculus, used to conjugate the initial system to a new one with a smoothing perturbation, and a KAM scheme, implemented to actually obtain reducibility. This makes possible to exhibit an example of reducibility for a higher dimensional Hamiltonian PDE, in a case where, in addition, the unperturbed problem has a spectrum which is dense on the real axis.

uk: вхід без авторизації

name: Reducibility of a transport equation on T^ d with unbounded perturbations


uk: Математика, природничі науки

description: A new compound method to compute periodic orbits in symplectic maps without the use of symmetries is presented. The results corroborate classical results from renormalization theory in examples not considered in the literature. Moreover the findings suggest a natural procedure to compute critical self-similar geometrical coefficients for these new cases.

uk: вхід без авторизації

name: Periodic orbits and symmetries in symplectic maps


uk: Математика, природничі науки

description: The quantum vortices of a superfluid are described as nodal lines of a solution to the time-dependent Gross-Pitaevskii equation. Experiments and extensive numerical computations show that quantum vortices cross, each of them breaking into two parts and exchanging part of itself for part of the other. This phenomenon is known as quantum vortex reconnection, and usually leads to a change of topology of the quantum vortices. In this talk I will show that, given any initial and final congurations of quantum vortices (which do not need to be topologically equivalent) and any conceivable way of reconnecting them (that is, of transforming one into the other), there is a Schwartz initial datum whose associated solution is smooth and realizes this specific vortex reconnection scenario. Key for the proof of this result is a new global approximation theorem for the linear Schrodinger equation, and the construction of pseudo-Seifert surfaces in spacetime. This is based on joint work with Alberto Enciso.

uk: вхід без авторизації

name: Approximation theorems for the Schrodinger equation and vortex reconnection in quantum fluids.


uk: Математика, природничі науки

description: In this talk we discuss families of homographic standing waves appearing from n vortex filaments rotating uniformly at a central configuration. The solution of the filaments are time periodic with periodic boundary conditions, i.e. this is a small divisor problem for a Hamiltonian partial differential equation which requires techniques related to KAM theory. In this case the Nash-Moser method gives rise to a family of solutions over a Cantor set of parameters. On the other hand, we show that when the relation between temporal and spatial periods is fixed at certain rational numbers, the contraction mapping theorem gives existence of an infinite number of families of standing waves that bifurcate from these configurations.

uk: вхід без авторизації

name: Small divisors and free vibrations in the n-vortex filament problem


uk: Математика, природничі науки

description: The systems of coupled NLS equations occur in some physical problems, in particular in nonlinear optics (coupling between two optical waveguides, pulses or polarized components...). From the mathematical point of view, the coupling effects can lead to truly nonlinear behaviors, such as the beating effect (solutions with Fourier modes exchanging energy) of Grébert, Paturel and Thomann (2013). In this talk, I will use the coupling between two NLS equations on the 1D torus to construct a family of linearly unstable tori, and therefore unstable quasi-periodic solutions. The idea is to take profit of the Hamiltonian structure of the system via the construction of a Birkhoff normal form and the application of a KAM theorem. In particular, we will see of this surprising behavior (this is the first example of unstable tori for a 1D PDE) is strongly related to the existence of beating solutions. This is a work in collaboration with Benoît Grébert (Université de Nantes).

uk: вхід без авторизації

name: Construction of unstable KAM tori for a system of coupled NLS equations.


uk: Математика, природничі науки

description: Breathers are periodic in time spatially localized solutions of evolutionary PDEs. They are known to exist for the sine-Gordon equation but are believed to be rare in other Klein-Gordon equations. Exchanging the roles of time and position, breathers can be interpreted as homoclinic solutions to a steady solution. In this talk, I will explain how to obtain an asymptotic formula for the distance between the stable and unstable manifold of the steady solution when the steady solution has weakly hyperbolic one dimensional stable and unstable manifolds. Their distance is exponentially small with respect to the amplitude of the breather and therefore classical perturbative techniques cannot be applied. This is a joint work with O. Gomide, T. Seara and C. Zeng.

uk: вхід без авторизації

name: On the break down of small amplitude breathers for the Klein-Gordon equation


uk: Математика, природничі науки

description: I will present a method for constructing quasi-periodic response solutions (i.e. quasi-periodic solutions with the same frequency as the forcing) for over-damped systems. Our method applies to non-linear wave equations subject to very strong damping and quasi-periodic external forcing and to the varactor equation in electronic engineering. The strong damping leads to very few small divisors which allows to prove the existence by using a contraction mapping argument requiring very weak non-resonance conditions on the frequency. This is joint work with A. Celletti, L. Corsi, and R. de la Llave.

uk: вхід без авторизації

name: Construction of quasi-periodic response solutions for forced systems with damping


uk: Математика, природничі науки

description: The problem of persistence of invariant tori in infinite dimension is a challenging problem in the study of PDEs. There is a rather well established literature on the persistence of n-dimensional invariant tori carrying a quasi-periodic Diophantine flow (for one-dimensional system) but very few on the persistence of infinite-dimensional ones. Inspired by the classical "twisted conjugacy theorem" of M. Herman for perturbations of degenerate Hamiltonians possessing a Diophantine invariant torus, we intend to present a compact and unified frame in which recover the results of Bourgain and Pöschel on the existence of almost-periodic solutions for the Nonlinear Schrödinger equation. We shall discuss the main advantages of our approach as well as new perspectives. This is a joint work with L. Biasco and M. Procesi.

uk: вхід без авторизації

name: Almost-periodic tori for the nonlinear Schrödinger equation


uk: Математика, природничі науки

description: Using spatial dynamics and results from the KAM theory, we develop a framework to find solutions of semilinear elliptic equations on the entire space which are quasiperiodic in one variable, decaying in the other variables. These results apply to a wide class of nonhomogeneous (and some homogeneous) problems. A careful application of Birkhoff normal form allows us to obtain a nondegeneracy condition for KAM that works even for some purely quadratic nonlinearities.

uk: вхід без авторизації

name: Partially localized solutions of elliptic equations on {R}^{N+1}


uk: Математика, природничі науки

description: I will present a renormalization problem about the convergence of normal forms in the presence of counterterms for some semiclassical systems that are close to be completely integrable. I will also explain some applications of these normal-form constructions to the study of quantum limits and semiclassical measures.

uk: вхід без авторизації

name: Renormalization of semiclassical KAM systems.


keywords:
Vargas-Magaña, Rosa Maria
Vargas-Magana, Rosa Maria

uk: Математика, природничі науки

description: The research is concerned with the study of dispersive shock waves (DSW), also termed undular bores, on the surface of fluids, DSWs arise due to the dispersive resolution of step, or near-step, initial conditions and are a common waveform in nature. They consist of a modulated dispersive wavetrain linking distinct levels ahead and behind it. In this talk, we will present some preliminary results related to the accuracy of DSW solutions of the Hamiltonian Bidirectional Whitham compared with fully nonlinear results. All research on DSWs to date has been based on weakly nonlinear approximations of full systems of equations, for instance, the water wave equations. The research of this project is the first attempt for the study of fully nonlinear DSWs. We will use the Whitham-Boussinesq (W-B) model that I introduced in my doctoral thesis as the bridge between the water wave equations (the free-surface Euler equations) and in which the "Shock fitting method” can be applied. This "Shock fitting method", derived by G. El and his collaborators, is a general method for determining the leading and trailing edges of DSWs, based on the dispersion relation for the governing nonlinear, dispersive wave equation.

uk: вхід без авторизації

name: Dispersive Shock waves in Hamiltonian Bidirectional Whitham systems


uk: Математика, природничі науки

description: In this talk I report on joint work with Patrick Gérard concerning the construction of global Birkhoff coordinates for the Benjamin-Ono equation. In these coordinates this equation can be solved by quadrature, meaning that it is an integrable (pseudo)differential equation in the strongest possible sense. The construction is based on the Lax pair formulation of this equation. I will present spectral properties of the Lax operator, discuss a generating function of the Benjamin-Ono hierarchy, which allows to establish various trace formulas, and introduce the Birkhoff coordinates. Furthermore, I will provide a characterization of finite gap solutions.

uk: вхід без авторизації

name: On the integrability of the Benjamin-Ono equation with periodic boundary conditions


uk: Математика, природничі науки

description: The neural crest offer a unique model system to study mechanisms of cell migration since cells are accessible to in vivo imaging and manipulation. Although cranial neural crest cells travel through dense extracellular matrix and mesoderm during vertebrate morphogenesis, very little is known how head tissue dynamics effect neural crest cell migratory behaviors. Here, we examine the relationship between neural crest cell and head mesoderm tissue dynamics using time-lapse imaging, computational modeling, and experimental manipulations in the chick embryo. I will discuss our discovery that head mesoderm dynamics vary dramatically in space and time during neural crest cell migration and share our comparison between model simulations with distinct domain growth profiles in normal and manipulated embryos. Together, our results raise intriguing questions how collective cell migration responds to underlying tissue dynamics during embryonic development and our approach offers a framework to consider this in a broader context of development and disease.

uk: вхід без авторизації

name: Neural Crest Cell Migration and Tissue Dynamics


uk: Математика, природничі науки

description: Neural crest cells migrate rapidly over long distances during early embryonic development of vertebrates, and their migration has been much studied as a model for chemotaxis and cancer metastasis. A curious observation is the "group advantage": in a chemokine gradient too shallow to induce a single cell to chemotax, a cluster of cells can demonstrate robust chemotaxis up the gradient. In this talk, I will describe a model that explains this behavior based on cell-cell interaction. Through contact inhibition and co-attraction, the cells modulate each other's Rac1 and RhoA dynamics on their membranes and achieve a common polarity. This affords a group of cells much stronger persistence in their chemotaxis than a single cell against ambient noise.

uk: вхід без авторизації

name: Group advantage in chemotaxis of neural crest cells


uk: Математика, природничі науки

description: Collective cell movement is closely related to normal development and cancer metastasis and scientists are studying it from different points of view, on different scales and using different biological systems. We would like to study its mechanism focusing on the mechanical and morphological effects using Cellular Potts Model. Our model is based on the experiments on the trunk ventral cells (TVCs) in Ciona cardiopharyngeal progenitors which include only two migratory cells so that it is the simplest case for collective cell movement. The observation in the experiment tells us that these two cells are polarized as leader and trailer cells with different morphological properties. So, we apply different mechanical properties for these two cells, such as adhesion, surface tension, protruding and retracting forces, to study their effects on cell shape, moving speed, and persistence in direction. We hope to see in what way two cells behave better than one.

uk: вхід без авторизації

name: Study the mechanical effect in collective movement of two cells using Cellular Potts Model


uk: Математика, природничі науки

description: Clusters of cells can work together in order to follow a signal gradient, chemotaxing even when single cells do not. This behavior is robust over many cell types and many signals, including gradients of extracellular matrix stiffness (durotaxis) and electrical potential (galvanotaxis). Cells in different regions of collectively migrating neural crest streams show different gene expression profiles, suggesting that cells may specialize to leader and follower roles in collective chemotaxis. We use a simple mathematical model to understand when this specialization would be advantageous. In our model, leader cells sense the gradient with an accuracy that depends on the kinetics of ligand-receptor binding while follower cells attempt to follow the cluster's direction with a finite error. Intuitively, specialization into leaders and followers should be optimal when a few cells have much more information than the rest of the cluster, such as in the presence of a sharp transition from one chemical concentration to another. We do find this - but also find that high levels of specialization can be optimal in the opposite limit of a very shallow gradient. This occurs because in a sufficiently shallow gradient, each leader cell has such little information about the gradient direction that - after a sufficient number of leaders are created - adding leader cells adds more noise to the cluster motion than adding a follower cell. There is also an important tradeoff: clusters have to choose between speed in following a gradient and ability to reorient quickly. We find that clusters with only a few leaders can take orders of magnitude more time to reorient than all-leader clusters.

uk: вхід без авторизації

name: Collective chemotaxis: collective guidance and leadership

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: In many biological processes, whether the formation of embryos or of tumors, cells dynamically organize in a context-dependent and spatiotemporal manner. These cells live and actively migrate in a heterogeneous environment of many cell types with different physical properties. For example, in many types of cancers such as colon, melanoma, prostrate and breast cancers, experiments have shown that the cancer cells are mechanically more deformable than the corresponding non-tumorigenic cells. It is also known that while non-cancerous (epithelial) cells tend to adhere to each other due to the adhesion protein E-cadherin and form a confluent tissue, in cancerous (mesenchymal) cells the expression of this protein is often heavily down-regulated. Motivated by this, we study the organization in a co-culture of two types of self-propelled particles (cells) with different stiffness and adhesion. We observe that the system phase separates into clusters with distinct morphologies and dynamics. We investigate the structure and growth of these segregating clusters with time by studying distribution functions and density structure factors, and characterize differences in the migration of the two cell types by studying their mean square displacements. Our results may elucidate how changes in cell mechano-adhesive properties during tumor progression impact cellular organization and dynamics in tumors.

uk: вхід без авторизації

name: Collective behavior in co-cultures of cells with different mechano-adhesive cells


uk: Математика, природничі науки

description: The robustness of biological performance, whether developmental or physiological, relies heavily on feedback control. The autocatalytic nature of cell proliferation makes such control especially important in tissue homeostasis, and multiple mechanisms of cell cooperation have been described—and seem to be universally necessary—just to balance cell turnover with spatially even, constant cell production, achieve physiologically desirable steady states, respond quickly to perturbations, and resist breaking down in the face of common somatic mutation. It is thus within the context of densely-connected networks of feedback control that cancers arise, yet the implications of this fact are little explored. I will discuss recent progress and current challenges in the quantitative understanding of proliferative dynamics and its control. In addition, I will argue that the fact that cancers, even as they progress, most likely retain pieces of the feedback control machinery that characterizes normal tissues, can help shed light on some of the common peculiarities of cancer, such as slow growth, arrest of benign tumors at fixed sizes, senescence or elimination of oncogene-expressing clones, dormancy, oscillatory responses to therapy, and the prevalence of hierarchical lineage structures ("cancer stem cells'').

uk: вхід без авторизації

name: The essential role of feedback in the control of proliferation: implications for normal biology and cancer


uk: Математика, природничі науки

description: Embryonic development requires the precise spatio-temporal activation of specific cell behaviours such as migration and division. Re-activation of these processes in adult cells is a hallmark of cancer. This makes experimental models for studying developmental processes, such as the fruit fly Drosophila melanogaster, highly informative for cancer studies: such research has often provided the first glimpse into the mechanism of action of human cancer-related proteins. In our lab, we use Drosophila to study the basic biology of epithelial-to-mesenchymal transitions (EMTs), as well as the collective migration of heterogenous cell populations, which results from partial-EMTs. We study these processes during normal development of the embryonic midgut, and also during tumour progression in an exciting new model of metastatic colorectal cancer that we recently generated. The collective migration of the embryonic midgut cells during Drosophila development is a particularly fascinating model for collective migration, as the midgut constitutes a mixed population of epithelial-like, mesenchymal and progenitor cells, yet midgut migration is highly coordinated both within and between these different cell types. Using the midgut as a paradigm, ongoing research in the lab is focused on identifying the mechanisms and mechanics of heterogeneous collective cell migration. Until recently, the study of midgut migration was restricted to simple qualitative analysis in fixed embryos, preventing quantification of cell-to-tissue scale behaviour. We recently pioneered live-imaging of midgut migration, enabled by multi-photon confocal microscopy, and have developed methods to perform 4-D tracking of the different cell populations within the migrating midgut. This has already allowed us to extract quantitative parameters and identify a novel role for E-cadherin mediating adhesion during cell migration. With our studies moving from qualitative descriptions to state-of-the-art deep-tissue imaging, quantitative analysis and generation of complex datasets, there is a pressing need to combine these innovative approaches with biophysical and computational modelling techniques, which we currently need help in developing.

uk: вхід без авторизації

name: Identifying the mechanisms and mechanics underlying collective migration of heterogeneous groups of cells


Mean Cluster Approach to Active Matter

uk: Математика, природничі науки

description: Cell migration is essential to cell sorting, playing a central role in tissue formation, wound healing, and tumor evolution. In a limit where inner cells are diluted when compared to outer cells, cell sorting can be described directly by the evolution of inner cells in a process of diffusion and fusion. Experiments show that far from finite size boundaries the average mass of inner cell clusters grows as a power law. In active matter systems, the dependency of the diffusion constant with the cluster mass does not follow the expected inverse relation but still preserves a simple relation. The diffusion constant depends on the cluster mass as a power law. In this work, we take into account this dependency within a Mean Cluster Approach (MCA). It results that, out of finite size limits, the average cluster mass evolves as a power law and its exponent depends only on the system dimension and on the exponent in the relation between diffusion constant and cluster mass, independent of the specific segregation mechanism. We confirm this simple prediction using simulations with different segregation hypotheses describing cell-cell interaction: differential adhesion hypothesis (DAH) and different velocities hypothesis (DVH). We performed MCA analysis and simulations below the transition to the ordered phase. However, system behavior above the transition is still not explored. Preliminary analytic and simulation results present a non-trivial positive exponent for the diffusion constant in the ordered phase. These results apply for active matter systems in general and, in particular, the mechanisms found underlying the increase in cell sorting speed and in cell crawling certainly has profound implications in biological evolution as a selection mechanism.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In this talk, I will present a mechanobiochemical model for 3D cell migration which couples the actomyosin dynamics described by a system of reaction-diffusion equations on evolving volumes and a force balance viscoelastic mechanical model for the cell displacements. The novelty is that the pressure and contractile forces are influenced by actin and myosin spatiotemporal dynamics. To analyse the model, we carry out linear stability analysis to determine key bifurcation parameters and find analytical solutions close to bifurcation points. To validate theoretical findings as well as study the longtime behaviour of the model system away from bifurcation points, we employ the evolving finite element method in multi-dimensions. Solutions predicted from linear stability theory are replicated in the early stages of cell movement. Subsequently, both simple and complex cell deformations such as expansions, protrusions, contractions and translations of the cell are observed. This theoretical and computational framework set premises for studying more complex and experimentally-driven reaction kinetics involving, actin, myosin and other molecular species coupled to mechanical properties that play an important role in cell movement and deformation. Cell movement is critical in multicellular organisms due to its role in embryogenesis, wound healing, immune response, cancer metastasis, tumour invasion, and other biomedical processes.

uk: вхід без авторизації

name: Unravelling a mechanobiochemical model for 3D cell migration


Modelling Epithelial Morphogenesis

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Exploring Dynamically Branching Structures by Agent-Based Modeling


uk: Математика, природничі науки

uk: вхід без авторизації

name: A novel approach to investigate transitions in tutor tissue architecture using computational topology


uk: Математика, природничі науки

description: The interface between a tumour and the adjacent stroma is a site of great importance for tumour development. At this site, carcinoma cells are highly proliferative, undergo invasive phenotypic changes, and directly interact with surrounding stromal cells, such as cancer-associated fibroblasts (CAFs) and immune cells, which further exert pro-tumourigenic effects. Here we describe the development of two tissue engineered platforms to probe these interactions: GLAnCE (Gels for Live Analysis of Compartmentalized Environments), an easy-to-use hydrogel-culture platform for investigating CAF-tumour cell interactions in vitro at a tumour-stroma interface, and TRACER a scaffold-based strategy that enables isolation of cells from specific regions within the tumour microenvironment to probe how cell-cell interactions and functions vary across gradients of microenvironmental factors such as oxygen.

uk: вхід без авторизації

name: Engineered models to probing cell behaviours in diseased and (re)egenerating microenvironmental


uk: Математика, природничі науки

description: Cancer invasion may be viewed as collective phenomenon emerging from the interplay of individual biological cells with their environment. Cell-based mathematical models can be used to decipher the rules of interaction. In these models cells are regarded as separate movable units. Here, we introduce an integrative modelling approach based on mesoscopic biological lattice-gas cellular automata (BIO-LGCA) to analyse collective effects in cancer invasion. This approach is rule- and cell-based, computationally efficient, and integrates statistical and biophysical models for different levels of biological knowledge. In particular, we provide BIO-LGCA models to analyse mechanisms of invasion in glioma and breast cancer cell lines. Ref.: Deutsch, A., Dormann, S.: Cellular automaton modeling of biological pattern formation: characterization, applications, and analysis. Birkhauser, Boston, 2018

uk: вхід без авторизації

name: Biological lattice-gas cellular automaton models for the analysis of collective effects in cancer invasion


uk: Математика, природничі науки

description: Pattern formation through reaction-diffusion of proteins is core to establishing functionally distinct domains within cells. In fact, cells are able to be in either a “rest state”, in which such proteins are distributed homogeneously along its interior, or in a “polarised” state, in which clear domains establish. This phenomenon of polarization, allows cells to change shape. Animal cells move accordingly to these domains, while plant cells, encased in a rigid cellulose cell wall, use them for cell shape changes and polar transmission of signals. Molecular studies reveal that even though plants and animals diverged 1.6 billion years ago, they still share the a similar core machinery required for cell shape changes. A fascinating similarity between animal and plant cells with respect to the organization of cytoskeletal elements in the regions of active protrusive growth and cell wall extension (the `leading edges'), is paralleled by a striking conserved molecular mechanism responsible for the creation and organization of these `leading edges'. To unravel and understand the interplay and feedbacks which brings about animate cell motility, we have developed a multiscale model of a motile cells, describing how the reaction-diffusion module can be biophysically coupled to the cells' deformation. We then contrast this to the cell shape changes that occur in the pavement cells (PCs) in the leaves: PCs grow multiple lobes, which fit perfectly into the indentations of the neighboring cells, generating interdigitating, jigsaw-like patterns. Finally, we use both systems to show how polarity formation can also be used as an integrator for sensing external cues, and discuss how alterations of this could cause tissue-level disruption. Hence, we argue that part of cell signaling can be seen as an outcome of feedbacks between intracellular reaction-diffusion patterning, cell shape dynamics and external signals. Lastly, I will show how our modelling framework can also be used for segmentation of imaging data, showing examp les that range from complex epithelia to organoids.

uk: вхід без авторизації

name: Getting into Shape: intracellular dynamics coupled to cell shape changes triggers emergent tissue responses


uk: Математика, природничі науки

description: Wild-type zebrafish feature black and yellow stripes across their body and fins, but mutants display a range of altered patterns, including spots and labyrinth curves. All these patterns form due to the interactions of pigment cells, which sort out through movement, birth, competition, and transitions in cellular shape during early development. The diversity of patterns on zebrafish makes it a useful organism for helping elucidate how genes, cell behavior, and visible animal characteristics are related, and the goal of our work is to help link genetic mutations to altered cell behaviors. Using an agent-based approach, we couple deterministic cell migration by ODEs with stochastic rules for updating population size to reproduce a range of fish patterns. Within a single zebrafish mutation, however, there is a lot of variability, and this makes it challenging to first identify the features of a pattern that we are trying to reproduce and then judge model success. Moreover, cells interact in a noisy environment on the fish skin, and model results need to be robust to realistic biological stochasticity. To help address these challenges, here we present a study of pattern variability and model robustness using topological tools to quantify zebrafish pattern features. This is joint work with Melissa McGuirl and Bjorn Sandstede.

uk: вхід без авторизації

name: Quantifying zebrafish pattern variability & robustness


uk: Математика, природничі науки

description: The concept of cell states is increasingly used to classify cellular behaviour in development, regeneration, and cancer. This is driven in part by a deluge of data comprising snapshots of cell populations at single-cell resolution. Yet quantitative predictive models of cell states and their transitions remain lacking. Such models could help, for example, to optimise differentiation protocols in vitro. Here, starting with a tractable immunostaining dataset of transcription factor expression we explore systematically if cell state transition rates can be inferred quantitatively and what information is required to do this. We investigate early cell fate decisions in primitive streak-like populations derived from epiblast stem cells (Tsakiridis et al., 2014). A particular challenge of the existing data is that labelling of cell states can be incomplete, i.e., not all of the markers that define a cell state are read out simultaneously in a given experiment. Using a top-down approach, we enumerate all possible cell states from known lineage markers, and build a minimal mathematical model for the transitions between these states in a growing colony. We adopt a Bayesian inference approach to quantify cell state transition rates and their uncertainties.

uk: вхід без авторизації

name: Inference of cell state transition rates in heterogeneous stem cell populations


uk: Математика, природничі науки

description: One of the major challenges in biology concerns the integration of data across length and time scales into a consistent framework: how do macroscopic properties and functionalities arise from the molecular regulatory networks and how do they evolve? Morphogenesis provides an excellent model system to study how simple molecular networks robustly control complex pattern forming processes. In my talk, I will focus on lung and kidney branching morphogenesis and discuss how chemical signaling and mechanical constraints shape the developing organs. Using light-sheet microscopy, we can observe epithelial dynamics during branching at cellular resolution, and I will discuss the physical principles of epithelial organization.

uk: вхід без авторизації

name: From Networks to Function – Computational Models of Organogenesis


uk: Математика, природничі науки

description: The control and downstream interpretation of gene expression dynamics is crucial in many biological contexts. For example, gene expression oscillations have been proposed to control the timing of cell differentiation during embryonic neurogenesis. However, mathematical analysis of gene expression dynamics may be hindered by sparse data and parameter uncertainty. Here, we combine Bayesian inference and quantitative experimental data on mouse and zebrafish neurogenesis to explore mechanisms controlling aperiodic and oscillatory gene expression dynamics during cell differentiation. We find that quantitatively accurate model predictions are possible despite high parameter uncertainty. We identify examples of stochastic amplification, where oscillations are enhanced by intrinsic noise and we show how such oscillations can be initiated by changes in biophysical parameters. We further consider mechanisms that may enable the down-stream interpretation of dynamic gene expression. Our analysis illustrates how quantitative modelling can help unravel fundamental mechanisms of dynamic gene regulation.

uk: вхід без авторизації

name: Roles of noise in shaping gene expression dynamics


uk: Математика, природничі науки

description: A critical first even in mammalian development is construction of the inner cell mass and trophoectoderm surrounding it. Using imaging and computational modeling, we show that by controlling the pace of cell fate specification, the embryo creates a crucial window of time where regulatory noise promotes accurate organization of these structures. Imaging results further indicate different gene products (Oct4 and Cdx2) exhibit significantly different levels of noise variation. Surprisingly, this asymmetry provides a novel means to balance the positive and negative influence of stochasticity. More generally, these results indicate noise has a positive role in spatially organizing the embryo.

uk: вхід без авторизації

name: Stochastically Organizing the Early Mammalian Embryo


uk: Математика, природничі науки

description: In this talk, I will discuss several examples, drawn from our ongoing studies in worm, fruit fly and ascidian embryos, in which strong coupling between biochemical signaling, force generation and transmission leads to complex emergent spatiotemporal dynamics. At the cellular scale, I will focus on spatiotemporal dynamics of pulsed contractility, and dynamic stabilization of cell polarity in one-cell C. elegans embryos. At the tissue scale, I will highlight two examples in which mechanochemical coupling drives waves of morphogenesis across a sheet of epithelial cells. My goal is to highlight My goal is to highlight a class of problems that could really benefit from development of new mathematical and computational tools.

uk: вхід без авторизації

name: Mechanochemical coupling and pattern formation at cell and tissue scales


uk: Математика, природничі науки

description: Retinal vasculature is essential for adequate oxygen supply to the inner layers of the retina, the light sensitive tissue in the eye. In embryonic development, formation of the retinal vasculature via angiogenesis is critically dependent on prior establishment of a mesh of astrocytes, which are a type of brain glial cell. Astrocytes emerge from the optic nerve head and then migrate over the retinal surface as a proliferating cell population in a radially symmetric manner. Astrocytes begin as stem cells, termed astrocyte precursor cells (APCs), then transition to immature perinatal astrocytes (IPAs), which eventually transition to mature astrocytes. We develop a partial differential equation model describing the migration of astrocytes where APCs and IPAs are represented as two subpopulations. Numerical simulations are compared to experimental data to assist in elucidating the mechanisms responsible for the distribution of astrocytes.

uk: вхід без авторизації

name: Spreading Mechanics and Differentiation of Astrocytes During Retinal Development


uk: Математика, природничі науки

description: Cutting-edge cancer treatments like immunotherapy and engineered microbes are examples of current and upcoming cell-based therapeutics. The success, failure, and side effects of these therapies critically depend upon multicellular cancer systems biology: the dynamical chemical and mechanical interactions between the engineered cells, tumor cells, and the microenvironment. Computational models can act as "virtual laboratories" for multicellular systems. The ideal laboratory would include cell and tissue biomechanics, biotransport of multiple chemical substrates including signaling factors, and many interacting cells. In this talk, we will introduce PhysiCell (\url{http://dx.doi.org/10.1371/journal.pcbi.1005991}), an open source agent-based platform for 3D multicellular systems biology. With this platform, desktop workstations can routinely simulate systems of ten or more cell-secreted chemical signals and tissue substrates, along with $10^5$ to $10^6$ individual cells that grow, divide, die, secrete chemical signals, move, exchange mechanical forces, and remodel their tissue microenvironment. After introducing PhysiCell, we will describe some recent projects that help expand its use. One project demonstrates how customized Jupyter notebook GUIs for PhysiCell models can be automatically generated and ported to nanoHUB (\url{https://nanohub.org}) where they can be run by anyone using just a Web browser. This makes it possible to 1) provide easy-to-run simulators to accompany models discussed in publications, and 2) let students submit demo simulators as part of class assignments and also be part of their academic portfolio. Another project describes two extreme-scale model explorations using the EMEWS framework on Cray supercomputers at Argonne National Lab. In our most recent collaboration, we explored a six-parameter therapeutic design space for cancer immunotherapy. This combined high-performance/high-throughput computing and active learning to optimize the immunotherapeutic design, characterize the topology (shape) of the design space, and automatically rank the importance of design parameters. We will close by pointing to some of the free online simulators and briefly discuss the future outlook for using high-throughput multicellular simulations to efficiently explore high-dimensional design spaces and accelerate discovery. Joint work with: Gary An, Nicholson Collier, Jonathan Ozik, and Paul Macklin.

uk: вхід без авторизації

name: Simulating cancer systems biology with PhysiCell: customized simulators, model exploration, and machine learning

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

uk: вхід без авторизації

name: Reproducible Virtual-Tissue Modeling: Challenges and Opportunities


uk: Математика, природничі науки

description: Scratch assays are standard in-vitro experimental methods for studying cell migration. In these experiments, a scratch is made on a cell monolayer and imaging of the recolonisation of the scratched region is performed to quantify cell migration rates. This experimental technique is commonly used in the pharmaceutical industry to identify new compounds that may promote cell migration in wound healing; and to evaluate the efficacy of potential drugs that inhibit cancer invasion. Two mathematical frameworks will be presented that analyse the dynamics of these experiments. First, a new migration quantification method will be presented that fits experimental data more closely than existing quantification methods, as well as providing a more accurate statistical classification of the migration rate between different assays. Moreover, it is also able to analyse experimental data of lower quality. The method’s robustness is validated using in-vitro and in-silico data. Then, an age-structured population model will be presented that aims to explain the two phases of proliferation in scratch assays previously observed experimentally. The cell population is modelled by a McKendrick-von Foerster partial differential equation. The conditions under which the model captures this two-phase behaviour are presented.

uk: вхід без авторизації

name: Quantitative frameworks for understanding cancer cell invasion through in-vitro scratch assays


uk: Математика, природничі науки

description: Cellular migration is a tightly regulated process that involves actin cytoskeleton, adaptor proteins, and integrin receptors. Forces are transmitted extracellularly through complexes of these molecules called adhesions. We recently developed a biophysical model of nascent adhesions (NA), as co-localized clusters of integrins and adaptor proteins, to understand their dynamics and mechanosensitive properties. The model was then analyzed to characterize the dependence of NA area on biophysical parameters that regulate the number of integrins and adaptor proteins within NA through a mechanosensitive co-aggregation mechanism. Our results revealed that NA formation is triggered beyond a threshold of adaptor protein, integrin, or extracellular ligand densities (listed in a decreasing order of relative influence), that an increase in co-aggregation or reductions in integrin mobility inside NA potentiate their formation, and that stress (rather than adhesion load) is the permissive mechanical parameter which allows for NA-assembly/disassembly via a bistable-switch possessing a hysteresis. These results were then confirmed by performing stochastic simulations of the model. In this talk, I will give an overview of the model and the predictions made in connection with experimental findings.

uk: вхід без авторизації

name: Dynamic and mechanosensitive properties of nascent adhesions


uk: Математика, природничі науки

description: Turing’s famous theory for explaining embryonic pattern formation, laid out in his seminal study ``The chemical basis of morphogenesis'', remains a cornerstone of theoretical biology and has inspired enormous interest, both from theoretical and experimental communities. Despite a number of ups and downs along the way, technical advances coupled to the increased collaboration between experimentalists and theoreticians has led to a number of convincing cases in which Turing’s idea may play a key role. In this talk I will recount some key milestones in the history of this theory and describe how it is clarifying our understanding of development in a number of processes, using our exploration of feather bud morphogenesis as a principal case study. Yet Turing’s paper opens with the disclaimer that ``This model will be a simplification and an idealization, and consequently a falsification.'' I will therefore also describe how recent results are pointing the way towards exciting new extensions and directions for Turing’s theory, particularly as links emerge between chemical-based and mechanical/cell motility based mechanisms for generating tissue pattern formation.

uk: вхід без авторизації

name: Turing’s model for morphogenesis: past, present, future


uk: Математика, природничі науки

description: Progression from a ductal carcinoma in situ (DCIS) to an invasive tumor is a major step initiating a devastating and often lethal metastatic cascade. We will discuss biological events leading to the formation of small invasive cohorts streaming from the DCIS. Using mathematical models on micro- and macro-scales integrated with information extracted from patients’ histology samples, we investigated how changes in the local microenvironmental niche near the DCIS edge enable initiation and progression of ductal microinvasions. Of particular interest are the biomechanical interactions between the cells and the ECM fiber structure, and microenvironmental features that define tumor niche prone to microinvasions.

uk: вхід без авторизації

name: Ductal Microinvasions: Cell and Matrix Interactions in Normal and Cancerous Tissues


uk: Математика, природничі науки

description: Two dominant models of mitotic spindle assembly are search-and-capture (SAC) and acentrosomal microtubule assembly (AMA). SAC predicts that kinetochores are captured randomly by dynamically unstable centrosomal microtubules (MTs), while AMA posits that kinetochore-associated MT bundles get integrated with centrosomal asters at random times. Both models predict a slow spindle assembly plagued by errors. Recent data shows that randomness in kinetochore capture is very low, that spindle assembles in relatively precise stages, and that small and dynamic MT ‘clouds’ near the kinetochores are critical in assisting centrosomal MTs in the spindle assembly. We used 3D tracking of centrosomes and kinetochores in mitotic animal cells to inform a computational model, according to which: 1) initially, when the centrosomes are proximal, the centrosomal MTs rapidly and indiscriminately ‘skewer’ the kinetochore MT clouds, effectively establishing lateral MT-kinetochore connections. When the pole-pole distance reaches a threshold, the polarity sorting of the kinetochore MTs and integration of the kinetochore and centrosomal MTs lead to establishing a vast majority of amphitelic attachments within a narrow time window.

uk: вхід без авторизації

name: Feedbacks between mechanics, geometry and polarity sorting ensured non-random, rapid and precise spindle assembly


uk: Математика, природничі науки

description: To form patterns in vivo or in vitro, cells must carefully coordinate their behavior. Here I will present mathematical modeling approaches for modeling cell-ECM cross-talk. The models predict how the ECM can regulate the shape of individual cells, and how it can coordinate collective cell behavior as it occurs, e.g., during the formation of blood vessels or the alignment of cells in muscles and tendons. After discussing these initial models, I will show how detailed measurements and new mathematical models of the mechanosensitive kinetics of focal adhesions have helped us to model cell-ECM interactions in more biophysical detail. I will sketch how this approach allows us to mechanistically predict changes in cell shape and in collective cell behavior from changes in focal adhesion kinetics, e.g., due to genetic knockouts or pharmacological treatment. I will end by showing our recent steps to include anisotropy of the cytoskeleton into our models. Altogether, our models help explain how local, cell-ECM interactions assist in global coordination of cell behavior during multicellular patterning.

uk: вхід без авторизації

name: Mathematical Modeling of Cell Shape and Collective Endothelial Cell Behavior due to cell-ECM cross-talk


uk: Математика, природничі науки

description: Accumulating experimental and clinical evidence suggests that the immune response to cancer is not exclusively anti-tumor. In fact, several pro-tumor effects of the immune system have been identified, such as production of growth factors, establishment of angiogenesis, inhibition of immune response, initiation of cell movement and metastasis, and establishment of metastatic niches. Based on experimental data, we develop a mathematical model for the immune-mediated theory of metastasis, which includes anti- and pro-tumor effects of the immune system. The immune-mediated theory of metastasis can explain dormancy of metastasis and metastatic blow-up after resection of the primary tumor. It can explain increased metastasis at sites of injury, and the relatively poor performance of Immunotherapies, due to pro-tumor effects of the immune system. Our results suggest that further work is warranted to fully elucidate and control the pro-tumor effects of the immune system in metastatic cancer. (with Adam Rhodes).

uk: вхід без авторизації

name: Mathematical Modeling of the Immune-Mediated Theory of Metastasis


keywords:
3-Säulen
3-Säulen-Modell
Hochschulfinanzierung
Grundfinanzierung
Innovationsorientierte Finanzierung
Leistungsorientierte Finanzierung
Bildungsmanagement
Wissenschaftsmanagement
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

de: Rechts-, Wirtschafts- und Sozialwissenschaften

uk: Право, економіка та суспільні науки

en: Law, Economics and Social Sciences

de: Wirtschaftswissenschaften

uk: Бізнес та економіка

en: Business and Economics

description: In diesem Screencast wird das 3-Säulen-Modell der Hochschulfinanzierung beschrieben und an einem Beispiel erklärt, wie das Modell in der Praxis anzuwenden ist. Die zugrundeliegende PowerPoint-Präsentation ist ebenfalls beigefügt. Das 3-Säulen-Modell basiert auf einer Grundfinanzierung, der leistungsorientierten Finanzierung und einer programm- bzw. innovationsorientierten Finanzierung. Neben der allgemeinen Definition der drei Säulen werden in diesem Screencast vor allem auch verwendbare Instrumente der Hochschulfinanzierung erläutert.

uk: вхід без авторизації

Hochschule Osnabrück

addressCountry: DE

addressLocality: Osnabrück

addressRegion: Lower Saxony


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Hochschule Osnabrück
Strategisches Management
Grundlagen
Strategieverständnis
Instrumentenumsetzung

uk: Право, економіка та суспільні науки

uk: Бізнес та економіка

description: Im Screencast-Video zu den Grundlagen des strategischen Managements geht es vor allem um die Grundbegriffe des strategischen Denkens und Handelns sowie um das Verständnis prozessualer Strategien und wie derartige Prozesse ideal umgesetzt werden können.

uk: вхід без авторизації

name: Grundlagen des Strategisches Management an Hochschulen


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Hochschule Osnabrück
Strategisches Management
Chancen und Grenzen

uk: Право, економіка та суспільні науки

uk: Бізнес та економіка

description: In diesem Screencast-Video geht es um die Chancen und Grenzen des strategische Managements für Wissenschaftseinrichtungen. Herr Prof. Ziegele geht auf die Notwendigkeit, aber auch auf die Probleme des strategischen Managements ein. Abschließend erläutert er außerdem die Schlussfolgerungen, die aus den Chancen und Grenzen des strategischen Managements entstehen.

uk: вхід без авторизації

name: Chancen, Grenzen und Risiken des strategischen Managements für Wissenschaftseinrichtungen


Profilbildung und Strategie

keywords:
Wissenschaftsmanagement
Bildungsmanagement
Profilbildung
Strategie
Strategisches Management
Profilierung
Qualitätsentwicklung

uk: Право, економіка та суспільні науки

description: In diesem Screencast erläutert Professor Ziegele erste Grundlagen dazu, wie und warum Profilbildung etwas mit Strategie von Hochschulen zu tun haben kann. Er erläutert zudem, welche wichtige Rolle die Qualitätsentwicklung im Gegensatz zur Profilierung im Rahmen der Strategieentwicklung von Hochschulen spielt.

uk: вхід без авторизації


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Profilbildung
Zukunft der Fachhochschule
Strategieoptionen
Strategie
Strategie von Hochschulen

uk: Право, економіка та суспільні науки

description: Im diesen Screencast für die Aufgaben zu Profilbildung und Strategie fasst Professor Ziegele die wichtigsten Ergebnisse der vorangegangen Quellen zusammen und erläutert verschiedene Überlegungen zu den vorher gestellten Aufgaben.

uk: вхід без авторизації

name: Lösungsansätze - Profilbildung und Strategie


Mission Statements

keywords:
Wissenschaftsmanagement
Bildungsmanagement
Mission statements
Leitbilder
Strategisches Management
Beispiele
Strategischer Prozess

uk: Право, економіка та суспільні науки

description: In diesem Screencast erklärt Professor Ziegele, welche Rolle "Mission Statements" oder in der Strategieentwicklung von Hochschulen spielen. Er zeigt dabei anhand praktischer Beispiele, welche Erwartungen und Probleme in Verbindung mit "Mission Statements" entstehen können und geht darauf ein welche grundlegenden Erfolgsfaktoren für erfolgreiche "Mission Statements" identifiziert werden können.

uk: вхід без авторизації


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Hochschule Osnabrück
Strategisches Management
Digitalisierung
Hochschulbildung
E-Learning
Learning Environment
Learning Spaces
Open Educational Resources
New Technology
Student Success

uk: Право, економіка та суспільні науки

description: In dem Video "Digital Transformation in Higher Education - The Future of Teaching and Learning" geht es um die Digitalisierung von Hochschulen und die Rolle Lehren und Lernen im digitalen Zeitalter. Die Referentin Dr. Budde geht dezidiert auf die Herausforderungen und Chancen digitalen Lehrens und Lernens ein und skizziert die notwendigen digitalen Kompetenzen im gegenwärtigen und zukünftigen wissenschaftlichen Arbeitsmarkt.

uk: вхід без авторизації


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Zielvereinbarung
Gegenstrom-Prinzip
Gegenstromverfahren
Zielorientierung
Strategische Perspektive
Ergebnisorientierung
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Право, економіка та суспільні науки

uk: Бізнес та економіка

description: In diesem Video erklärt Professor Ziegele, welche Merkmale Zielvereinbarungen haben sollten um ideal in der Praxis eingesetzt werden zu können.

uk: вхід без авторизації

name: Merkmale von Zielvereinbarungen - Screencast


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Zielvereinbarung
Dezentrale Planung
Profilierung
Hochschulweite Ziele
SWOT
Finanzielle Flexibilität
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Право, економіка та суспільні науки

uk: Бізнес та економіка

description: In diesem Video erklärt Professor Ziegele, welche Funktionen Zielvereinbarungen bei der Gestaltung von Mittelverteilungsmodellen haben können. Die Aspekte werden durch praxisnahe Beispiele erklärt und veranschaulicht.

uk: вхід без авторизації

name: Funktionen von Zielvereinbarungen - Screencast


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Formelgebundene Finanzierung
Finanzierungsformel
Formelfinanzierung
Mittelverteilung
Bemessung
Verteilung
Hochschulmanagement
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Право, економіка та суспільні науки

uk: Бізнес та економіка

description: Dies ist Teil 1 von 3 der Screencastreihe Formelgebundene Mittelverteilung Checkliste. Professor Ziegele erklärt in diesem Screencast, welche Aspekte bei der Gestaltung einer Formel beachtet werden sollen und geht auf mögliche Schwierigkeiten in der praktischen Umsetzung ein.

uk: вхід без авторизації

name: Formelgebundende Mittelverteilung Checkliste 1 - Screencast


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Mittelverteilung
Formelgebundene Finanzierung
Formelfinanzierung
Finanzierungsformel
Formel
Hochschulmanagement
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Право, економіка та суспільні науки

uk: Бізнес та економіка

description: Dies ist Teil 2 von 3 der Screencastreihe Formelgebundene Mittelverteilung Checkliste. Professor Ziegele erklärt in diesem Screencast, welche Aspekte bei der Gestaltung einer Formel beachtet werden sollen und geht auf mögliche Schwierigkeiten in der praktischen Umsetzung ein.

uk: вхід без авторизації

name: Formelgebundende Mittelverteilung Checkliste 2 - Screencast


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Formelgebundene Finanzierung
Finanzzierungsformel
Formelfinanzierung
Formel
Mittelverteilung
Hochschulmanagement
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Право, економіка та суспільні науки

uk: Бізнес та економіка

description: Dies ist Teil 3 von 3 der Screencastreihe Formelgebundene Mittelverteilung Checkliste. Professor Ziegele erklärt in diesem Screencast, welche Aspekte bei der Gestaltung einer Formel beachtet werden sollen und geht auf mögliche Schwierigkeiten in der praktischen Umsetzung ein.

uk: вхід без авторизації

name: Formelgebundende Mittelverteilung Checkliste 3 - Screencast


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Mittelvergabe
Forschungsleistung
Zielkonflikt
Kappungsdilemma
Hochschulebene
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Право, економіка та суспільні науки

uk: Бізнес та економіка

description: In diesem Screencast erklärt Professor Ziegele, welche Probleme bei der Mittelvergabe auftreten können. Er geht dabei mit praktischen Beispielen darauf ein, wie einige dieser Probleme bei der Gestaltung von Mittelvergabeinstrumenten umgangen werden können.

uk: вхід без авторизації

name: Gängige Probleme der Mittelvergabe - Screencast