Article
Neurosciences
Lindsey M. Crown, Daniel T. Gray, Lesley A. Schimanski, Carol A. Barnes, Stephen L. Cowen
Summary: This study investigates the effects of locomotor activity and age on gamma and theta frequencies in the hippocampus of rats. The results show that age affects the modulation of gamma and theta frequencies, with older rats showing slower increases in gamma frequency and lower theta frequencies. Acceleration is also found to have a lower correlation with gamma frequency in both age groups. Older animals have greater spike phase-locking to gamma and reduced firing rates within place fields, but higher spatial information content per spike. These findings suggest that locomotor behavior and age significantly impact local-field potential activity in the hippocampus.
JOURNAL OF NEUROSCIENCE
(2022)
Article
Psychiatry
Zhen Li, Rong Chen, Dachuan Liu, Xizhe Wang, Wei Yuan
Summary: This study investigated the effects of low-intensity transcranial ultrasound stimulation (TUS) on theta and gamma oscillations in the hippocampus under different behavioral states. The results showed that TUS enhanced the absolute power of theta and gamma oscillations in the anesthesia and awake states, but weakened their phase-amplitude coupling (PAC) under the running state. Additionally, the relative power of theta and gamma oscillations changed with ultrasound intensity, and the PAC index between theta and gamma increased with ultrasound intensity. These findings suggest that TUS can modulate hippocampal oscillations depending on the behavioral state.
FRONTIERS IN PSYCHIATRY
(2023)
Article
Chemistry, Physical
Xinli Wang, Canying Cai, Guangwen Zhou
Summary: This study elucidates the interfacial dynamics of hafnium with gamma-Al2O3 and theta-Al2O3 during the oxidation of Ni-Al alloys. The presence of interfacial Al vacancies plays a critical role in influencing the interfacial segregation of Hf atoms and HfO2 formation. The results provide insights into manipulating the interfacial transport process of reactive elements by controlling the phase and stoichiometry of the transient oxide phases.
APPLIED SURFACE SCIENCE
(2022)
Article
Neurosciences
Tony Ye, Mitchell J. Bartlett, Scott J. Sherman, Torsten Falk, Stephen L. Cowen
Summary: This study focused on the impact of LID on neural circuitry and synchrony, investigated the effects of L-DOPA dosage and exposure duration on these impacts, and explored the effects of sub-anesthetic ketamine treatment on LID. Novel neural signatures were identified related to LID and ketamine treatment.
EXPERIMENTAL NEUROLOGY
(2021)
Article
Astronomy & Astrophysics
Jaume Zuriaga-Puig, Viviana Gammaldi, Daniele Gaggero, Thomas Lacroix, M. A. Sanchez-Conde
Summary: This paper presents a comprehensive study of the gamma-ray flux observed in the Galactic Center using the H.E.S.S. telescope. The aim of the study is to constrain the distribution of dark matter in the region and investigate the possibility of a density enhancement near the supermassive black hole Sgr A*. The results support the hypothesis of an enhanced dark matter density in the Galactic Center and provide guidance for future studies using current and next-generation telescopes.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Multidisciplinary Sciences
Pallavi Kaushik, Amir Moye, Marieke Van Vugt, Partha Pratim Roy
Summary: This study investigated the possibility of predicting attention and distraction using EEG data collected in a natural setting, and demonstrated that data extracted in daily life settings can accurately predict attention states, potentially leading to the development of Brain-Computer Interfaces for real-time attention tracking.
SCIENTIFIC REPORTS
(2022)
Article
Neurosciences
Brittany K. Taylor, Elizabeth Heinrichs-Grahama, Jacob A. Eastman, Michaela R. Frenzel, Yu-Ping Wang, Vince D. Calhoun, Julia M. Stephen, Tony W. Wilsona
Summary: This study examines the developmental trajectory of fluid reasoning and its neural oscillatory dynamics in children and adolescents. The findings indicate a stable optimization of fluid reasoning abilities over time, along with changes in neural activity that are associated with improvements in task performance.
Article
Mathematics, Applied
Ruslan Kulaev, Alexandra Urtaeva
Summary: In this paper, the spectral properties of a fourth-order differential operator on a network, which models the Euler-Bernoulli beam system, are studied. A new approach based on the concept of a sign-constant zone for a continuous function on a graph is proposed for developing oscillatory spectral theory of the operator. It is shown that the eigenvalues and eigenfunctions of the corresponding operator on a network exhibit oscillatory properties, and a condition for the simplicity of eigenvalues is established. Furthermore, the distribution of zeros of eigenfunctions is investigated, and it is demonstrated that the k-th eigenfunction has exactly k zeros on the graph.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Biology
Eloy Parra-Barrero, Kamran Diba, Sen Cheng
Summary: The study examines the relationships between theta phase, represented position, and true location in navigation through space in mammalian brains. Existing concepts of 'spatial' or 'temporal' theta sweeps are found to be inadequate in explaining how relevant variables change with running speed. A new concept of 'behavior-dependent' sweeps is introduced, where theta sweep length and place field properties vary based on running speed characteristics at different locations in the environment, providing essential structured heterogeneity for understanding the hippocampal code.
Article
Mathematics, Applied
Xiaoqing Chi, Xiaoyun Jiang
Summary: This paper investigates the numerical solution for a two-dimensional generalized Oldroyd-B fluid on a semi-infinite domain, proposing a numerical method and proving its stability and convergence. Numerical examples are implemented to further validate the theoretical analysis.
APPLIED MATHEMATICS AND COMPUTATION
(2021)
Article
Mathematics
Julia Elyseeva
Summary: This paper investigates two linear Hamiltonian differential systems that depend nonlinearly on the spectral parameter. With Dirichlet boundary conditions, the main result of the paper, the relative oscillation theorem, connects the difference in the numbers of finite eigenvalues of the two problems to the oscillation numbers associated with the Wronskian of the principal solutions. The paper also presents the renormalized oscillation theorems as a corollary.
MATHEMATISCHE NACHRICHTEN
(2023)
Article
Neurosciences
Jack P. Kennedy, Yuchen Zhou, Y. Qin, Sarah D. Lovett, A. Sheremet, S. N. Burke, A. P. Maurer
Summary: This study explores the relationship between theta rhythm and voluntary movement in hippocampal neurophysiology research, highlighting the impact of running speed on theta frequency and power compared to acceleration. The results suggest that speed plays a more significant role in influencing theta frequency, contradicting previous findings that acceleration is the dominant factor. Caution is advised in interpreting absolute claims about hippocampal physiology from single behavioral repertoires, emphasizing the need to consider multiple sensory inputs in navigation tasks.
JOURNAL OF NEUROSCIENCE
(2022)
Article
Engineering, Aerospace
Lei Qiao, Jiakuan Xu, Junqiang Bai, Yang Zhang
Summary: A novel transition closure model is proposed for three-dimensional hypersonic boundary layers considering crossflow effects. Through parameter analyses and numerical validation, the model shows high accuracy and compatibility in predicting crossflow-induced transition.
Article
Neurosciences
B. S. Katerman, Y. Li, J. K. Pazdera, C. Keane, M. J. Kahana
Summary: This study investigated spectral EEG biomarkers of memory retrieval and found that in the moments leading up to recall, there was an increase in theta (4-8 Hz) power, a decrease in alpha (8-20 Hz) power, and an increase in gamma (40-128 Hz) power. This spectral pattern could distinguish between long-term delay and immediate recall conditions.
Article
Mechanics
Marco Mondelli, Ramji Venkataramanan
Summary: The study focuses on estimating signals from measurements obtained via a generalized linear model, proposing an AMP algorithm initialized with a spectral estimator and rigorously characterizing its performance in the high-dimensional limit.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Mathematics, Applied
Melanie Kobras, Valerio Lucarini, Maarten H. P. Ambaum
Summary: In this study, a minimal dynamical system derived from the classical Phillips two-level model is introduced to investigate the interaction between eddies and mean flow. The study finds that the horizontal shape of the eddies can lead to three distinct dynamical regimes, and these regimes undergo transitions depending on the intensity of external baroclinic forcing. Additionally, the study provides insights into the continuous or discontinuous transitions of atmospheric properties between different regimes.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Shu-hong Xue, Yun-yun Yang, Biao Feng, Hai-long Yu, Li Wang
Summary: This research focuses on the robustness of multiplex networks and proposes a new index to measure their stability under malicious attacks. The effectiveness of this method is verified in real multiplex networks.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Julien Nespoulous, Guillaume Perrin, Christine Funfschilling, Christian Soize
Summary: This paper focuses on optimizing driver commands to limit energy consumption of trains under punctuality and security constraints. A four-step approach is proposed, involving simplified modeling, parameter identification, reformulation of the optimization problem, and using evolutionary algorithms. The challenge lies in integrating uncertainties into the optimization problem.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Alain Bourdier, Jean-Claude Diels, Hassen Ghalila, Olivier Delage
Summary: In this article, the influence of a turbulent atmosphere on the growth of modulational instability, which is the cause of multiple filamentation, is studied. It is found that considering the stochastic behavior of the refractive index leads to a decrease in the growth rate of this instability. Good qualitative agreement between analytical and numerical results is obtained.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Ling An, Liming Ling, Xiaoen Zhang
Summary: In this paper, an integrable fractional derivative nonlinear Schrodinger equation is proposed and a reconstruction formula of the solution is obtained by constructing an appropriate Riemann-Hilbert problem. The explicit fractional N-soliton solution and the rigorous verification of the fractional one-soliton solution are presented.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Marzia Bisi, Nadia Loy
Summary: This paper proposes and investigates general kinetic models with transition probabilities that can describe the simultaneous change of multiple microscopic states of the interacting agents. The mathematical properties of the kinetic model are proved, and the quasi-invariant asymptotic regime is studied and compared with other models. Numerical tests are performed to demonstrate the time evolution of distribution functions and macroscopic fields.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Carlos A. Pires, David Docquier, Stephane Vannitsem
Summary: This study presents a general theory for computing information transfers in nonlinear stochastic systems driven by deterministic forcings and additive and/or multiplicative noises. It extends the Liang-Kleeman framework of causality inference to nonlinear cases based on information transfer across system variables. The study introduces an effective method called the 'Causal Sensitivity Method' (CSM) for computing the rates of Shannon entropy transfer between selected causal and consequential variables. The CSM method is robust, cheaper, and less data-demanding than traditional methods, and it opens new perspectives on real-world applications.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Feiting Fan, Minzhi Wei
Summary: This paper focuses on the existence of periodic and solitary waves for a quintic Benjamin-Bona-Mahony (BBM) equation with distributed delay and diffused perturbation. By transforming the corresponding traveling wave equation into a three-dimensional dynamical system and applying geometric singular perturbation theory, the existence of periodic and solitary waves are established. The uniqueness of periodic waves and the monotonicity of wave speed are also analyzed.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Wangbo Luo, Yanxiang Zhao
Summary: We propose a generalized Ohta-Kawasaki model to study the nonlocal effect on pattern formation in binary systems with long-range interactions. In the 1D case, the model displays similar bubble patterns as the standard model, but Fourier analysis reveals that the optimal number of bubbles for the generalized model may have an upper bound.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Corentin Correia, Ana Cristina Moreira Freitas, Jorge Milhazes Freitas
Summary: The emergence of clustering of rare events is due to periodicity, where fast returns to target sets lead to a bulk of high observations. In this research, we explore the potential of a new mechanism to create clustering of rare events by linking observable functions to a finite number of points belonging to the same orbit. We show that with the right choice of system and observable, any given cluster size distribution can be obtained.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Enyu Fan, Changpin Li
Summary: This paper numerically studies the Allen-Cahn equations with different kinds of time fractional derivatives and investigates the influences of time derivatives on the solutions of the considered models.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Yuhang Zhu, Yinghao Zhao, Chaolin Song, Zeyu Wang
Summary: In this study, a novel approach called Time-Variant Reliability Updating (TVRU) is proposed, which integrates Kriging-based time-dependent reliability with parallel learning. This method enhances risk assessment in complex systems, showcasing exceptional efficiency and accuracy.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Chiara Cecilia Maiocchi, Valerio Lucarini, Andrey Gritsun, Yuzuru Sato
Summary: The predictability of weather and climate is influenced by the state-dependent nature of atmospheric systems. The presence of special atmospheric states, such as blockings, is associated with anomalous instability. Chaotic systems, like the attractor of the Lorenz '96 model, exhibit heterogeneity in their dynamical properties, including the number of unstable dimensions. The variability of unstable dimensions is linked to the presence of finite-time Lyapunov exponents that fluctuate around zero. These findings have implications for understanding the structural stability and behavior modeling of high-dimensional chaotic systems.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Christian Klein, Goksu Oruc
Summary: A numerical study on the fractional Camassa-Holm equations is conducted to construct smooth solitary waves and investigate their stability. The long-time behavior of solutions for general localized initial data from the Schwartz class of rapidly decreasing functions is also studied. Additionally, the appearance of dispersive shock waves is explored.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Vasily E. Tarasov
Summary: This paper extends the standard action principle and the first Noether theorem to consider the general form of nonlocality in time and describes dissipative and non-Lagrangian nonlinear systems. The general fractional calculus is used to handle a wide class of nonlocalities in time compared to the usual fractional calculus. The nonlocality is described by a pair of operator kernels belonging to the Luchko set. The non-holonomic variation equations of the Sedov type are used to describe the motion equations of a wide class of dissipative and non-Lagrangian systems. Additionally, the equations of motion are considered not only with general fractional derivatives but also with general fractional integrals. An application example is presented.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
