Article
Physics, Fluids & Plasmas
Edgar Knobloch, Hannes Uecker, Arik Yochelis
Summary: The article explains the formation of jumping oscillons through the modulational instability of excitable traveling pulses, and also reveals the existence and stability of bound states of oscillons and pulses, including patches of such states. This rich variety of spatiotemporal states can be utilized for information and storage processing.
Article
Multidisciplinary Sciences
Jianhua Zhang, Wen Zheng, Shiyun Zhang, Ding Xu, Yunhuan Nie, Zhehua Jiang, Ning Xu
Summary: This study explores the definition of temperature for nonequilibrium systems, focusing on fluctuation-dissipation temperatures and proposing that they represent characteristic temperatures of their equilibrium counterparts. By calculating the fluctuation-dissipation relation of inherent structures, a temperature-like quantity T-IS is obtained, which matches with crystallization temperature T-c for crystal-formers and onset temperature T-on for glass-formers. The research reveals the nature of effective temperatures, the connections between nonequilibrium and equilibrium systems, and confirms the equivalence between T-on and T-c.
Article
Mathematics, Interdisciplinary Applications
Sanjeev Kumar Sharma, Arnab Mondal, Argha Mondal, M. A. Aziz-Alaoui, Ranjit Kumar Upadhyay, Jun Ma
Summary: In this study, we explore the complex behavior of neural computation using a biophysically motivated model. We identify the occurrence of mixed mode oscillations (MMOs) and mixed mode bursting oscillations (MMBOs) induced by canard phenomenon, and analyze the bifurcation structure of the system under injected current stimulus. The findings contribute to a better understanding of the rich and complex responses of neurons.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Multidisciplinary Sciences
Johannes Vierock, Enrico Peter, Christiane Grimm, Andrey Rozenberg, I-Wen Chen, Linda Tillert, Alejandro G. Castro Scalise, Marilu Casini, Sandra Augustin, Dimitrii Tanese, Benoit C. Forget, Remi Peyronnet, Franziska Schneider-Warme, Valentina Emiliani, Oded Beja, Peter Hegemann
Summary: This article reports on the molecular analysis of recently discovered KCRs and the identification of a novel type of hydrophobic K+ selectivity filter. Among these, WiChR from Wobblia lunata features a highly selective KCR signature motif, stable photocurrents, and prolonged open-state lifetime, making it suitable for low irradiance and reduced tissue heating single- and two-photon inhibition in cardiac myocytes and neurons.
Article
Physics, Multidisciplinary
Jasmin Imran Alsous, Jan Rozman, Robert A. Marmion, Andrej Kosmrlj, Stanislav Y. Shvartsman
Summary: As tissues grow, a small fraction of cells can give rise to a large fraction of the tissue. This clonal dominance can emerge spontaneously, in the absence of pre-existing biases, as a collective property of evolving excitable networks. The spatial coupling of excitable units explains a critical feature of organism development, with implications for tissue organization and dynamics.
Article
Engineering, Mechanical
A. Yassine Karoui, Remco I. Leine
Summary: In this paper, a reduced-order model of a slow-fast piecewise linear 2-DOF oscillator subjected to harmonic excitation is obtained using singular perturbation theory. The study investigates the nonsmooth nonlinearity of piecewise linear nature with bilinear damping and bilinear stiffness characteristics. A continuous matching of the locally invariant slow manifolds obtained in each subregion of the state space is proposed, resulting in a reduced-order model that has the same nature as the full dynamics. The frequency-response curves from both the full system and the reduced-order models indicate that the proposed reduction method can capture nonlinear behaviors such as super- and subharmonic resonances.
NONLINEAR DYNAMICS
(2023)
Article
Mathematics, Applied
Irina Bashkirtseva, Lev Ryashko
Summary: This paper considers the problem of probabilistic analysis of stochastic phenomena in slow-fast dynamical systems modeling biochemical reactions. It studies how multiplicative noise induces systematic shifts of probabilistic distributions and forms phantom attractors in nonlinear enzymatic models. The mathematical analysis of the underlying probabilistic mechanism of such stochastic transformations is performed using the freeze-and-average method. The theoretical results are supported by direct numerical simulation.
Article
Neurosciences
Markus Meister
Summary: Animals can learn efficiently from a single experience and adapt their future behavior. Fast learning is related to genetic encoding, while slow learning is acquired through unsupervised learning from the environment.
CURRENT OPINION IN NEUROBIOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Peipei Cen, Zixin He, Runmei Ding, Huifang Yang, Li Li, Yi-Quan Zhang, Yonghong Li, Danian Tian, Xiangyu Liu
Summary: A mononuclear dysprosium complex with single-molecule magnet behavior was synthesized, and dilution experiments revealed the molecular origin of the magnetic behavior. Ab initio calculations were used to discuss the relaxation mechanisms and magneto-structure relationship.
Article
Physics, Multidisciplinary
Khady Diagne, Thomas M. Bury, Marc W. Deyell, Zachary Laksman, Alvin Shrier, Gil Bub, Leon Glass
Summary: We studied the dynamics generated by two periodic sources with different frequencies in excitable cardiac tissue culture using optogenetic techniques. The observed rhythms showed unexpected regularities related to classic results in number theory, which can be modeled and analyzed using cellular automata. These findings have potential applications in identifying cardiac arrhythmias caused by competing pacemakers in humans.
PHYSICAL REVIEW LETTERS
(2023)
Article
Mathematics, Applied
Arnab Mondal, Argha Mondal, Sanjeev Kumar Sharma, Ranjit Kumar Upadhyay, Chris G. Antonopoulos
Summary: This paper investigates an excitable biophysical system that facilitates the propagation of nerve impulses and explores the mechanisms and characteristics of spatiotemporal patterns formed in different brain areas. The study reveals various neural excitabilities and conditions for spiral-wave formation, providing insights into the collective behavior of coupled excitable systems with diverse firing characteristics in irregular neural dynamics.
Article
Physics, Multidisciplinary
Yaru Liu, Shenquan Liu, Bo Lu, Juergen Kurths
Summary: This article explores the dynamics of mixed-mode oscillations (MMOs) in the auditory cortex based on the calcium-based inner hair cells (IHCs) model, revealing the mechanism of MMOs generation using the geometric singular perturbation theory (GSPT). The analysis shows that system parameters control the oscillation patterns in the IHCs model, with many new oscillations occurring. The study also conducts dynamic analysis using slow-fast analysis and bifurcation analysis, uncovering the underlying dynamic properties of perturbed systems under singular perturbation theory.
Article
Mathematics, Applied
Yan-Yu Chen, Hirokazu Ninomiya, Chang-Hong Wu
Summary: This study investigates the global dynamics of a one-dimensional free boundary problem in the singular limit of a FitzHugh-Nagumo type reaction-diffusion system. By introducing the notion of symbolic dynamics, the asymptotic behaviors of solutions are classified into three categories: convergence to resting state, convergence to a series of traveling pulses, and convergence to a propagating wave consisting of multiple traveling pulses and fronts.
SIAM JOURNAL ON MATHEMATICAL ANALYSIS
(2021)
Article
Mathematics, Applied
Pedro Toniol Cardin
Summary: This paper provides a geometric analysis of relaxation oscillations in the context of planar fast-slow systems with a discontinuous right-hand side. The conditions for the existence of a stable crossing limit cycle and the convergence of the cycle to a crossing closed singular trajectory are given. The regularization of the crossing relaxation oscillator and the existence of a relaxation oscillation in the regularized vector field are studied. The results are demonstrated with examples including a model of an arch bridge with nonlinear viscous damping.
Article
Multidisciplinary Sciences
Seungtaek Lee, Juho Lee, Yeonguk Kim, Seokyong Jeong, Dong Eon Kim, Gunsu Yun
Summary: In supercritical fluids, simple fluids are believed to be homogeneous, but experiments show that liquid droplets can survive for a surprisingly long time in a supercritical background.
NATURE COMMUNICATIONS
(2021)