Observation of fast oscillations in the magnetoresistance of the Bechgaard salt(TMTSF)2SbF6

1998 ◽  
Vol 58 (21) ◽  
pp. 14476-14478 ◽  
Author(s):  
D. Vignolles ◽  
J. P. Ulmet ◽  
M. J. Naughton ◽  
L. Binet ◽  
J. M. Fabre
Keyword(s):  
Bechgaard Salt ◽  
Fast Oscillations

High-field magnetoresistance of the Bechgaard salt (TMTSF)2AsF6:Fast oscillations and spin-density-wave transition

1997 ◽  
Vol 55 (5) ◽  
pp. 3024-3027 ◽  
Author(s):  
Jean Pierre Ulmet ◽  
Abdelhadi Narjis ◽  
Michael J. Naughton ◽  
Jean Marc Fabre
Keyword(s):  
Spin Density ◽  
High Field ◽  
Density Wave ◽  
Spin Density Wave ◽  
Bechgaard Salt ◽  
Fast Oscillations

High field magnetoresistance and fast oscillations in the Bechgaard salt (TMTSF)2AsF6

1997 ◽  
Vol 86 (1-3) ◽  
pp. 2075-2076
Author(s):  
J.P. Ulmet ◽  
A. Narjis ◽  
S. Askenazy ◽  
M.J. Naughton ◽  
J.M. Fabre
Keyword(s):  
High Field ◽  
Bechgaard Salt ◽  
Fast Oscillations

Twin Boundary in Bechgaard Salt: Structure and Unusual Dynamics

1996 ◽  
Vol 6 (12) ◽  
pp. 1567-1574 ◽  
Author(s):  
M. Mukoujima ◽  
K. Kawabata ◽  
T. Sambongi
Keyword(s):  
Twin Boundary ◽  
Salt Structure ◽  
Bechgaard Salt

Reduced TMS-evoked fast oscillations in the motor cortex predict the severity of positive symptoms in first-episode psychosis

2021 ◽  
pp. 110387
Author(s):  
Francesco Luciano Donati ◽  
Rachel Kaskie ◽  
Catarina Cardoso Reis ◽  
Armando D'Agostino ◽  
Adenauer Girardi Casali ◽  
...  
Keyword(s):  
Motor Cortex ◽  
First Episode Psychosis ◽  
First Episode ◽  
Positive Symptoms ◽  
Episode Psychosis ◽  
Fast Oscillations

scholarly journals Complex partial synchronization patterns in networks of delay-coupled neurons

2019 ◽  
Vol 377 (2153) ◽  
pp. 20180128 ◽  
Author(s):  
D. Nikitin ◽  
I. Omelchenko ◽  
A. Zakharova ◽  
M. Avetyan ◽  
A. L. Fradkov ◽  
...  
Keyword(s):  
Nonlinear Dynamics ◽  
Temporal Dynamics ◽  
Delay Systems ◽  
Theme Issue ◽  
Partial Synchronization ◽  
Multiplex Network ◽  
Control Scheme ◽  
Non Local ◽  
Spatio Temporal ◽  
Fast Oscillations

We study the spatio-temporal dynamics of a multiplex network of delay-coupled FitzHugh–Nagumo oscillators with non-local and fractal connectivities. Apart from chimera states, a new regime of coexistence of slow and fast oscillations is found. An analytical explanation for the emergence of such coexisting partial synchronization patterns is given. Furthermore, we propose a control scheme for the number of fast and slow neurons in each layer. This article is part of the theme issue ‘Nonlinear dynamics of delay systems’.

scholarly journals Ion motion in the current sheet with sheared magnetic field – Part 1: Quasi-adiabatic theory

2013 ◽  
Vol 20 (1) ◽  
pp. 163-178 ◽  
Author(s):  
A. V. Artemyev ◽  
A. I. Neishtadt ◽  
L. M. Zelenyi
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Analytical Description ◽  
Particle Energy ◽  
Tangential Component ◽  
Adiabatic Invariant ◽  
Ion Motion ◽  
Adiabatic Theory ◽  
Fast Oscillations ◽  
The Magnetic Field

Abstract. We present a theory of trapped ion motion in the magnetotail current sheet with a constant dawn–dusk component of the magnetic field. Particle trajectories are described analytically using the quasi-adiabatic invariant corresponding to averaging of fast oscillations around the tangential component of the magnetic field. We consider particle dynamics in the quasi-adiabatic approximation and demonstrate that the principal role is played by large (so called geometrical) jumps of the quasi-adiabatic invariant. These jumps appear due to the current sheet asymmetry related to the presence of the dawn–dusk magnetic field. The analytical description is compared with results of numerical integration. We show that there are four possible regimes of particle motion. Each regime is characterized by certain ranges of values of the dawn–dusk magnetic field and particle energy. We find the critical value of the dawn–dusk magnetic field, where jumps of the quasi-adiabatic invariant vanish.

scholarly journals Detection and Magnetic Source Imaging of Fast Oscillations (40–160 Hz) Recorded with Magnetoencephalography in Focal Epilepsy Patients

2016 ◽  
Vol 29 (2) ◽  
pp. 218-231 ◽  
Author(s):  
Nicolás von Ellenrieder ◽  
Giovanni Pellegrino ◽  
Tanguy Hedrich ◽  
Jean Gotman ◽  
Jean-Marc Lina ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Magnetic Source ◽  
Fast Oscillations

scholarly journals Theta activity paradoxically boosts gamma and ripple frequency sensitivity in prefrontal interneurons

2021 ◽  
Vol 118 (51) ◽  
pp. e2114549118
Author(s):  
Ricardo Martins Merino ◽  
Carolina Leon-Pinzon ◽  
Walter Stühmer ◽  
Martin Möck ◽  
Jochen F. Staiger ◽  
...  
Keyword(s):  
Low Frequency ◽  
Gamma Oscillations ◽  
Brain State ◽  
Gabaergic Interneurons ◽  
Time Resolved ◽  
Cortical Rhythms ◽  
Brain States ◽  
Fast Spiking ◽  
Fast Oscillations ◽  
Cross Frequency Coupling

Fast oscillations in cortical circuits critically depend on GABAergic interneurons. Which interneuron types and populations can drive different cortical rhythms, however, remains unresolved and may depend on brain state. Here, we measured the sensitivity of different GABAergic interneurons in prefrontal cortex under conditions mimicking distinct brain states. While fast-spiking neurons always exhibited a wide bandwidth of around 400 Hz, the response properties of spike-frequency adapting interneurons switched with the background input’s statistics. Slowly fluctuating background activity, as typical for sleep or quiet wakefulness, dramatically boosted the neurons’ sensitivity to gamma and ripple frequencies. We developed a time-resolved dynamic gain analysis and revealed rapid sensitivity modulations that enable neurons to periodically boost gamma oscillations and ripples during specific phases of ongoing low-frequency oscillations. This mechanism predicts these prefrontal interneurons to be exquisitely sensitive to high-frequency ripples, especially during brain states characterized by slow rhythms, and to contribute substantially to theta-gamma cross-frequency coupling.

scholarly journals Synchronization and Bursting Activity in the Model for Two Predator-Prey Systems Coupled By Predator Migration

2019 ◽  
Vol 14 (2) ◽  
pp. 588-611
Author(s):  
M.P. Kulakov ◽  
E.V. Kurilova ◽  
E.Ya. Frisman
Keyword(s):  
Phase Synchronization ◽  
Oscillation Period ◽  
Logistic Growth ◽  
Predator Prey ◽  
Different Types ◽  
The Difference ◽  
Minimum Numbers ◽  
Fast Oscillations ◽  
Bursting Activity ◽  
Type Ii Functional Response

The papers is devoted to a model for two non-identical predator-prey communities coupled by migration and characterized by logistic growth of prey and Holling type II functional response. The coupling is a predator migration at constant weak rate. The non-identity is the difference in the prey growth rates or predator mortalities in each patch. We studied the equilibrium states of model and scenarios of loss of their stability and emerge of complex periodic solutions. It was shown that in some domains of the parameter space there is a bursting activity which are that the dynamics of two communities contain segments of slowly resting dynamic (as part of a fast-slow cycle or canard) and regular bursts of spikes. In the resting part, the dynamics of the second community, as a rule, follow the slow changes in the first community, i.e. the dynamics in different patches are synchronous. But in the fast part there is only phase synchronization between the fast-slow cycle in first patch and bursts in second. We classified the scenarios of transition between different types of bursting activity by location spiking manifold and canard. These types differ not so much in size, shape or numbers of spikes as in the order of bursts emerge relative a slow-fast cycle. In a typical case the start of burst (divergent fast oscillations) coincides with the minimum numbers or quasi-extinction of prey in the first patch. After a rapid increase in the prey number in the first patch, diverging fluctuations give way to damped in the second patch. Such dynamics correspond to the rhombus-wave shape of spikes cluster. Another case is interesting, when the burst of spikes is formed after the full recovery of prey and with a certain predator number in the first patch. In this case, the spikes cluster takes the shape of a triangle-wave or a truncated rhombus-wave. It was shown that transitions between these types of bursts are accompanied by a change in the oscillation period and the degree of synchronization. Triangular-wave bursters correspond to complete synchronization of the predator dynamics in the resting part and rhomboid-wave correspond to antiphase synchronization. In the fast part with many spikes, communities are completely asynchronous to each other.

Sign in / Sign up

Export Citation Format

Share Document