Search results for " Oscillation"
showing 10 items of 845 documents
Parametrical Optomechanical Oscillations in PhoXonic Whispering Gallery Mode Resonators
2019
AbstractWe report on the experimental and theoretical analysis of parametrical optomechanical oscillations in hollow spherical phoxonic whispering gallery mode resonators due to radiation pressure. The optically excited acoustic eigenmodes of the phoxonic cavity oscillate regeneratively leading to parametric oscillation instabilities.
The impact of the 2015/2016 El Niño on global photosynthesis using satellite remote sensing
2018
The El Niño-Southern Oscillation exerts a large influence on global climate regimes and on the global carbon cycle. Although El Niño is known to be associated with a reduction of the global total land carbon sink, results based on prognostic models or measurements disagree over the relative contribution of photosynthesis to the reduced sink. Here, we provide an independent remote sensing-based analysis on the impact of the 2015–2016 El Niño on global photosynthesis using six global satellite-based photosynthesis products and a global solar-induced fluorescence (SIF) dataset. An ensemble of satellite-based photosynthesis products showed a negative anomaly of −0.7 ± 1.2 PgC in 2015, but a sli…
Sustained oscillations in the MAP kinase cascade.
2016
Abstract The MAP kinase cascade is a network of enzymatic reactions arranged in layers. In each layer occurs a multiple futile cycle of phosphorylations. The fully phosphorylated substrate then serves as an enzyme for the layer below. This paper focuses on the existence of parameters for which Hopf bifurcations occur and generate periodic orbits. Furthermore it is explained how geometric singular perturbation theory allows to generalize results from simple models to more complex ones.
Mechanisms Underlying Memory Consolidation by Adult-Born Neurons During Sleep
2020
The mammalian hippocampus generates new neurons that incorporate into existing neuronal networks throughout the lifespan, which bestows a unique form of cellular plasticity to the memory system. Recently, we found that hippocampal adult-born neurons (ABNs) that were active during learning reactivate during subsequent rapid eye movement (REM) sleep and provided causal evidence that ABN activity during REM sleep is necessary for memory consolidation. Here, we describe the potential underlying mechanisms by highlighting distinct characteristics of ABNs including decoupled firing from local oscillations and ability to undergo profound synaptic remodeling in response to experience. We further di…
Hippocampal theta phase-contingent memory retrieval in delay and trace eyeblink conditioning
2017
Hippocampal theta oscillations (3-12Hz) play a prominent role in learning. It has been suggested that encoding and retrieval of memories are supported by different phases of the theta cycle. Our previous study on trace eyeblink conditioning in rabbits suggests that the timing of the conditioned stimulus (CS) in relation to theta phase affects encoding but not retrieval of the memory trace. Here, we directly tested the effects of hippocampal theta phase on memory retrieval in two experiments conducted on adult female New Zealand White rabbits. In Experiment 1, animals were trained in trace eyeblink conditioning followed by extinction, and memory retrieval was tested by presenting the CS at t…
Behavioral and Electrophysiological Arguments in Favor of a Relationship between Impulsivity, Risk-Taking, and Success on the Iowa Gambling Task
2019
The aim of the present study was to investigate the relationship between trait impulsivity, risk-taking, and decision-making performance. We recruited 20 healthy participants who performed the Iowa Gambling Task (IGT) and the Balloon Analog Risk Task (BART) to measure decision-making and risk-taking. The impulsivity was measured by the Barratt Impulsiveness Scale. Resting-state neural activity was recorded to explore whether brain oscillatory rhythms provide important information about the dispositional trait of impulsivity. We found a significant correlation between the ability to develop a successful strategy and the propensity to take more risks in the first trials of the BART. Risk-taki…
On Functions of Integrable Mean Oscillation
2005
Given f 2 L1(T) we denote by wmo(f) the modulus of mean oscillation given by wmo(f)(t) = sup 0 0 such that Z 1 0 [wmo(f)(t)]p dt t Z 1 0 [who(f)(t)]p dt t Cp Z 1 0 [wmo(f)(t)]p dt t. -Oscar.Blasco@uv.es
Accretion in strong field gravity with eXTP
2019
In this paper we describe the potential of the enhanced X-ray Timing and Polarimetry (eXTP) mission for studies related to accretion flows in the strong field gravity regime around both stellar-mass and supermassive black-holes. eXTP has the unique capability of using advanced 'spectral-timing-polarimetry' techniques to analyze the rapid variations with three orthogonal diagnostics of the flow and its geometry, yielding unprecedented insight into the inner accreting regions, the effects of strong field gravity on the material within them and the powerful outflows which are driven by the accretion process.
Acute effects of cold pack on mechanical properties of the quadriceps muscle in healthy subjects.
2012
Purpose: To examine the effects of local cooling on mechanical properties of the quadriceps muscle in healthy subjects. Subjects: Thirty-nine healthy subjects (27 women, 12 men, mean age 39, range 20e62) volunteered. Methods: A cold gel pack was applied to the quadriceps muscle for 20 min. Properties were quantified by analyzing the frequency (tension), decrement (elasticity) and stiffness of damped oscillations and the compliance of the muscle before, immediately after and after 15-min after cooling. Results: The largest responses immediately after cooling were seen in the oscillation decrement parameter, 7.9 (3.7e12.1) %, and in the compliance parameter, � 7.5 (� 9.8 to � 5.3) %. Response…
Influence of cognitive-motor expertise on brain dynamics of anticipatory-based outcome processing.
2019
Motor experience plays an important role in the ability to anticipate action outcomes, but little is known about the brain processes through which it modulates the preparation for unexpected events. To address this issue, EEG was employed while table tennis players and novices observed videos of serves in order to predict the expected ball direction based on the kinematics of a model's movement. Furthermore, we manipulated the congruency between the model's body kinematics and the subsequent ball trajectory while assessing the cerebral cortical activity of novices and experts to understand how experts respond to unexpected outcomes. Experts were more accurate in predicting the ball trajecto…