Article
Mathematics, Applied
Jennifer Lopez, Mattia Coccolo, Ruben Capeans, Miguel A. F. Sanjuan
Summary: In this study, a method is proposed to control the orbits of the two-dimensional Rulkov model affected by bounded noise. The phase space exhibits two chaotic regions separated by a transient chaotic region. The control technique allows the neuron to exhibit very long burstings by connecting both chaotic regions. A region Q and an advantageous set S symbolscript Q are defined to drive the orbits with minimal control, and the set S changes with the noise intensity and can be used in different control scenarios.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Mathematics, Applied
Siyu Guo, Albert C. J. Luo
Summary: This study analytically presents infinite homoclinic orbits induced by unstable periodic orbits in the Lorenz system. The stable and unstable periodic motions to chaos on the period-doubling cascaded bifurcation trees are determined using a discrete mapping method. Examples of period-1, period-2, and period-4 motions on a period-doubling bifurcation tree are generated, with corresponding homoclinic orbits relative to these unstable periodic orbits determined. Illustrations of homoclinic orbits and periodic orbits are provided, presenting a method to determine infinite homoclinic orbits through unstable periodic orbits in three-dimensional or higher-dimensional nonlinear systems.
Article
Engineering, Mechanical
Andre Gusso, Sebastian Ujevic, Ricardo L. Viana
Summary: Numerical demonstration shows that two-frequency excitation can effectively induce chaos in the Duffing oscillator with single- and double-well potentials, with chaos being robust in the latter case. The robust chaos is characterized by the existence of a single chaotic attractor unaffected by parameter changes, necessary for practical applications to prevent chaos destruction by fabrication tolerances, external influences, and aging.
NONLINEAR DYNAMICS
(2021)
Article
Multidisciplinary Sciences
Jerome Hardouin, Claire Dore, Justine Laurent, Teresa Lopez-Leon, Jordi Ignes-Mullol, Francesc Sagues
Summary: This study reveals that active liquid crystals can develop active boundary layers that polarize the confining walls regardless of their curvature. The accumulation of negatively-charged defects in the boundary layer influences the dynamics of the system and can even fully control the behavior of the active liquid crystals.
NATURE COMMUNICATIONS
(2022)
Editorial Material
Physics, Multidisciplinary
Jakub Zakrzewski
Summary: Two experiments with cold atoms have shown how many-body interactions can suppress dynamical localization in a periodically kicked quantum rotor.
Article
Agriculture, Dairy & Animal Science
Marina Bottrel, Isabel Ortiz, Manuel Hidalgo, Maria Diaz-Jimenez, Blasa Pereira, Cesar Consuegra, Mohamed Samy Yousef, Jesus Dorado
Summary: Embryo transfer is crucial for endangered species like donkeys, where manipulation of cycles is important to maximize the number of embryos obtained. This study compared the effectiveness of two prostaglandins and two ovulation-inducing agents in 26 fertile embryo donor jennies. Both prostaglandins were effective in shortening cycles, while DES was more efficient in inducing ovulation. High uterine edema was associated with lower embryo quality.
Article
Physics, Multidisciplinary
Joseph Hall, Simon Malzard, Eva-Maria Graefe
Summary: In this work, a semiclassical phase-space density of Schur vectors in non-Hermitian quantum systems is constructed, where each Schur vector is associated with a single Planck cell. The Schur states are organized based on a classical norm landscape on phase space, which reflects the lifetimes characteristic of non-Hermitian systems. The construction is applied to a complex example of a PT-symmetric kicked rotor in the regimes of mixed and chaotic classical dynamics to demonstrate its generality.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Christophe Letellier, Irene Sendina-Nadal, Ludovico Minati, I. Leyva
Summary: In a network of identical dynamical systems, nodes within the same degree class differentiate in a similar manner and visit a sequence of states of diverse complexity independently of the global network structure.
Article
Physics, Fluids & Plasmas
Hidetsugu Sakaguchi, Keito Yamasaki
Summary: We consider control methods for spiking from a nonlinear dynamics perspective. In the FitzHugh-Nagumo model, the repetitive spiking can be suppressed by periodic sinusoidal force with high frequency, and we study this transition numerically and through linear stability analysis. We also study coupled FitzHugh-Nagumo equations and find that periodic forcing induces chaos, leading to desynchronization and weakened total output of spiking in a certain parameter range. Additionally, we propose a feedback control method for spiking frequency, which allows for achieving desired spiking and bursting frequency.
Article
Mechanics
Shijie Qin, Shijun Liao
Summary: In this paper, the authors study the three-dimensional steady-state Arnold-Beltrami-Childress (ABC) flow of fluid, which exhibits a chaotic Lagrangian structure and satisfies the Navier-Stokes equations. They discover the existence of ultra-chaos in Lagrangian trajectories of fluid particles, where the statistical properties are highly sensitive to tiny disturbances. Numerical experiments show that the transition from laminar to turbulence leads to the emergence of ultra-chaos in most fluid particles. The authors discuss the relationships between ultra-chaos and concepts such as the Poincare section, ergodicity/non-ergodicity, and turbulence.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Plant Sciences
Kamila Godel-Jedrychowska, Katarzyna Kulinska-Lukaszek, Ewa Kurczynska
Summary: The research found that the symplasmic domains between somatic embryos (SEs) and zygotic embryos (ZEs) were similar, but there were spatial-temporal differences in the symplasmic transport restriction. These findings provide a new perspective on intercellular signaling during embryonic development.
FRONTIERS IN PLANT SCIENCE
(2021)
Article
Mathematics, Applied
Dennis Duncan, Christoph Raeth
Summary: This study investigates the predictive capabilities of three different architectures for hybrid reservoir computing and finds that the output hybrid approach is the most favorable in terms of accuracy and interpretability. It also demonstrates that all hybrid reservoir computing approaches significantly improve the prediction results, provided that the model is sufficiently accurate.
Article
Agriculture, Dairy & Animal Science
Lakshmi Devi Huidrom, Shital Nagargoje Dhanaji, Sriti Pandey, Vikash Chandra, Taru Sharma Gutulla
Summary: Early embryonic loss is a major cause of repeat breeding in buffalo. Proper communication between the embryo and maternal system is crucial for successful pregnancy outcomes. The embryo releases specific molecules as signals to the maternal endometrium for survival and continued pregnancy. Understanding the molecular cross-talk between the embryo and uterine endometrium is important for improving IVF outcomes.
Article
Mathematics, Applied
Zbigniew Galias
Summary: The dynamics of the Colpitts oscillator with an exponential nonlinearity are studied using rigorous interval arithmetic based tools. The existence of various types of periodic attractors is proved by employing the interval Newton method. The main findings include the construction of a trapping region for the associated return map in the chaotic case, and the computation of a rigorous lower bound for the value of the topological entropy, which confirms the topological chaotic nature of the system. A systematic search for unstable periodic orbits embedded in the chaotic attractor is conducted, and the results are used to obtain an accurate approximation of the topological entropy of the system.
Article
Engineering, Mechanical
Ruben Capeans, Miguel A. F. Sanjuan
Summary: Partial control is a technique used in systems with transient chaos to prevent the escape of orbits from a specific region. By finding a safe set within this region, chaotic orbits can be sustained with minimal control. This study presents a control strategy using a safety function to gradually guide chaotic orbits into the safe set, ultimately transforming it into a global attractor.
NONLINEAR DYNAMICS
(2022)
