TY - JOUR
AB - We consider various modeling levels for spatially homogeneous chemical reaction systems, namely the chemical master equation, the chemical Langevin dynamics, and the reaction-rate equation. Throughout we restrict our study to the case where the microscopic system satisfies the detailed-balance condition. The latter allows us to enrich the systems with a gradient structure, i.e. the evolution is given by a gradient-flow equation. We present the arising links between the associated gradient structures that are driven by the relative entropy of the detailed-balance steady state. The limit of large volumes is studied in the sense of evolutionary Γ-convergence of gradient flows. Moreover, we use the gradient structures to derive hybrid models for coupling different modeling levels.
AU - Maas, Jan
AU - Mielke, Alexander
ID - 8758
IS - 6
JF - Journal of Statistical Physics
SN - 00224715
TI - Modeling of chemical reaction systems with detailed balance using gradient structures
VL - 181
ER -
TY - DATA
AU - Guseinov, Ruslan
ID - 8761
TI - Supplementary data for "Computational design of cold bent glass façades"
ER -
TY - JOUR
AB - This paper introduces a simple method for simulating highly anisotropic elastoplastic material behaviors like the dissolution of fibrous phenomena (splintering wood, shredding bales of hay) and materials composed of large numbers of irregularly‐shaped bodies (piles of twigs, pencils, or cards). We introduce a simple transformation of the anisotropic problem into an equivalent isotropic one, and we solve this new “fictitious” isotropic problem using an existing simulator based on the material point method. Our approach results in minimal changes to existing simulators, and it allows us to re‐use popular isotropic plasticity models like the Drucker‐Prager yield criterion instead of inventing new anisotropic plasticity models for every phenomenon we wish to simulate.
AU - Schreck, Camille
AU - Wojtan, Christopher J
ID - 8765
IS - 2
JF - Computer Graphics Forum
KW - Computer Networks and Communications
SN - 0167-7055
TI - A practical method for animating anisotropic elastoplastic materials
VL - 39
ER -
TY - JOUR
AB - Resources are rarely distributed uniformly within a population. Heterogeneity in the concentration of a drug, the quality of breeding sites, or wealth can all affect evolutionary dynamics. In this study, we represent a collection of properties affecting the fitness at a given location using a color. A green node is rich in resources while a red node is poorer. More colors can represent a broader spectrum of resource qualities. For a population evolving according to the birth-death Moran model, the first question we address is which structures, identified by graph connectivity and graph coloring, are evolutionarily equivalent. We prove that all properly two-colored, undirected, regular graphs are evolutionarily equivalent (where “properly colored” means that no two neighbors have the same color). We then compare the effects of background heterogeneity on properly two-colored graphs to those with alternative schemes in which the colors are permuted. Finally, we discuss dynamic coloring as a model for spatiotemporal resource fluctuations, and we illustrate that random dynamic colorings often diminish the effects of background heterogeneity relative to a proper two-coloring.
AU - Kaveh, Kamran
AU - McAvoy, Alex
AU - Chatterjee, Krishnendu
AU - Nowak, Martin A.
ID - 8767
IS - 11
JF - PLOS Computational Biology
KW - Ecology
KW - Modelling and Simulation
KW - Computational Theory and Mathematics
KW - Genetics
KW - Ecology
KW - Evolution
KW - Behavior and Systematics
KW - Molecular Biology
KW - Cellular and Molecular Neuroscience
SN - 1553-734X
TI - The Moran process on 2-chromatic graphs
VL - 16
ER -
TY - JOUR
AB - One of the hallmarks of quantum statistics, tightly entwined with the concept of topological phases of matter, is the prediction of anyons. Although anyons are predicted to be realized in certain fractional quantum Hall systems, they have not yet been unambiguously detected in experiment. Here we introduce a simple quantum impurity model, where bosonic or fermionic impurities turn into anyons as a consequence of their interaction with the surrounding many-particle bath. A cloud of phonons dresses each impurity in such a way that it effectively attaches fluxes or vortices to it and thereby converts it into an Abelian anyon. The corresponding quantum impurity model, first, provides a different approach to the numerical solution of the many-anyon problem, along with a concrete perspective of anyons as emergent quasiparticles built from composite bosons or fermions. More importantly, the model paves the way toward realizing anyons using impurities in crystal lattices as well as ultracold gases. In particular, we consider two heavy electrons interacting with a two-dimensional lattice crystal in a magnetic field, and show that when the impurity-bath system is rotated at the cyclotron frequency, impurities behave as anyons as a consequence of the angular momentum exchange between the impurities and the bath. A possible experimental realization is proposed by identifying the statistics parameter in terms of the mean-square distance of the impurities and the magnetization of the impurity-bath system, both of which are accessible to experiment. Another proposed application is impurities immersed in a two-dimensional weakly interacting Bose gas.
AU - Yakaboylu, Enderalp
AU - Ghazaryan, Areg
AU - Lundholm, D.
AU - Rougerie, N.
AU - Lemeshko, Mikhail
AU - Seiringer, Robert
ID - 8769
IS - 14
JF - Physical Review B
SN - 2469-9950
TI - Quantum impurity model for anyons
VL - 102
ER -
TY - JOUR
AB - Breakdown of vascular barriers is a major complication of inflammatory diseases. Anucleate platelets form blood-clots during thrombosis, but also play a crucial role in inflammation. While spatio-temporal dynamics of clot formation are well characterized, the cell-biological mechanisms of platelet recruitment to inflammatory micro-environments remain incompletely understood. Here we identify Arp2/3-dependent lamellipodia formation as a prominent morphological feature of immune-responsive platelets. Platelets use lamellipodia to scan for fibrin(ogen) deposited on the inflamed vasculature and to directionally spread, to polarize and to govern haptotactic migration along gradients of the adhesive ligand. Platelet-specific abrogation of Arp2/3 interferes with haptotactic repositioning of platelets to microlesions, thus impairing vascular sealing and provoking inflammatory microbleeding. During infection, haptotaxis promotes capture of bacteria and prevents hematogenic dissemination, rendering platelets gate-keepers of the inflamed microvasculature. Consequently, these findings identify haptotaxis as a key effector function of immune-responsive platelets.
AU - Nicolai, Leo
AU - Schiefelbein, Karin
AU - Lipsky, Silvia
AU - Leunig, Alexander
AU - Hoffknecht, Marie
AU - Pekayvaz, Kami
AU - Raude, Ben
AU - Marx, Charlotte
AU - Ehrlich, Andreas
AU - Pircher, Joachim
AU - Zhang, Zhe
AU - Saleh, Inas
AU - Marel, Anna-Kristina
AU - Löf, Achim
AU - Petzold, Tobias
AU - Lorenz, Michael
AU - Stark, Konstantin
AU - Pick, Robert
AU - Rosenberger, Gerhild
AU - Weckbach, Ludwig
AU - Uhl, Bernd
AU - Xia, Sheng
AU - Reichel, Christoph Andreas
AU - Walzog, Barbara
AU - Schulz, Christian
AU - Zheden, Vanessa
AU - Bender, Markus
AU - Li, Rong
AU - Massberg, Steffen
AU - Gärtner, Florian R
ID - 8787
JF - Nature Communications
TI - Vascular surveillance by haptotactic blood platelets in inflammation and infection
VL - 11
ER -
TY - JOUR
AB - Cooperation is a ubiquitous and beneficial behavioural trait despite being prone to exploitation by free-riders. Hence, cooperative populations are prone to invasions by selfish individuals. However, a population consisting of only free-riders typically does not survive. Thus, cooperators and free-riders often coexist in some proportion. An evolutionary version of a Snowdrift Game proved its efficiency in analysing this phenomenon. However, what if the system has already reached its stable state but was perturbed due to a change in environmental conditions? Then, individuals may have to re-learn their effective strategies. To address this, we consider behavioural mistakes in strategic choice execution, which we refer to as incompetence. Parametrising the propensity to make such mistakes allows for a mathematical description of learning. We compare strategies based on their relative strategic advantage relying on both fitness and learning factors. When strategies are learned at distinct rates, allowing learning according to a prescribed order is optimal. Interestingly, the strategy with the lowest strategic advantage should be learnt first if we are to optimise fitness over the learning path. Then, the differences between strategies are balanced out in order to minimise the effect of behavioural uncertainty.
AU - Kleshnina, Maria
AU - Streipert, Sabrina
AU - Filar, Jerzy
AU - Chatterjee, Krishnendu
ID - 8789
IS - 11
JF - Mathematics
TI - Prioritised learning in snowdrift-type games
VL - 8
ER -
TY - JOUR
AB - Reachability analysis aims at identifying states reachable by a system within a given time horizon. This task is known to be computationally expensive for linear hybrid systems. Reachability analysis works by iteratively applying continuous and discrete post operators to compute states reachable according to continuous and discrete dynamics, respectively. In this article, we enhance both of these operators and make sure that most of the involved computations are performed in low-dimensional state space. In particular, we improve the continuous-post operator by performing computations in high-dimensional state space only for time intervals relevant for the subsequent application of the discrete-post operator. Furthermore, the new discrete-post operator performs low-dimensional computations by leveraging the structure of the guard and assignment of a considered transition. We illustrate the potential of our approach on a number of challenging benchmarks.
AU - Bogomolov, Sergiy
AU - Forets, Marcelo
AU - Frehse, Goran
AU - Potomkin, Kostiantyn
AU - Schilling, Christian
ID - 8790
IS - 11
JF - IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
SN - 02780070
TI - Reachability analysis of linear hybrid systems via block decomposition
VL - 39
ER -
TY - GEN
AB - When divergent populations are connected by gene flow, the establishment of complete reproductive isolation usually requires the joint action of multiple barrier effects. One example where multiple barrier effects are coupled consists of a single trait that is under divergent natural selection and also mediates assortative mating. Such multiple-effect traits can strongly reduce gene flow. However, there are few cases where patterns of assortative mating have been described quantitatively and their impact on gene flow has been determined. Two ecotypes of the coastal marine snail, Littorina saxatilis, occur in North Atlantic rocky-shore habitats dominated by either crab predation or wave action. There is evidence for divergent natural selection acting on size, and size-assortative mating has previously been documented. Here, we analyze the mating pattern in L. saxatilis with respect to size in intensively-sampled transects across boundaries between the habitats. We show that the mating pattern is mostly conserved between ecotypes and that it generates both assortment and directional sexual selection for small male size. Using simulations, we show that the mating pattern can contribute to reproductive isolation between ecotypes but the barrier to gene flow is likely strengthened more by sexual selection than by assortment.
AU - Perini, Samuel
AU - Rafajlovic, Marina
AU - Westram, Anja M
AU - Johannesson, Kerstin
AU - Butlin, Roger
ID - 8809
TI - Data from: Assortative mating, sexual selection and their consequences for gene flow in Littorina
ER -
TY - JOUR
AB - We develop a geometric version of the circle method and use it to compute the compactly supported cohomology of the space of rational curves through a point on a smooth affine hypersurface of sufficiently low degree.
AU - Browning, Timothy D
AU - Sawin, Will
ID - 177
IS - 3
JF - Annals of Mathematics
TI - A geometric version of the circle method
VL - 191
ER -