Search results for " Oscillation"
showing 10 items of 845 documents
Positive impacts of important bird and biodiversity areas on wintering waterbirds under changing temperatures throughout Europe and North Africa
2020
Clausen, Preben/0000-0001-8986-294X WOS: 000536149100018 Migratory waterbirds require an effectively conserved cohesive network of wetland areas throughout their range and life-cycle. Under rapid climate change, protected area (PA) networks need to be able to accommodate climate-driven range shifts in wildlife if they are to continue to be effective in the future. Thus, we investigated geographical variation in the relationship between local temperature anomaly and the abundance of 61 waterbird species during the wintering season across Europe and North Africa during 1990-2015. We also compared the spatio-temporal effects on abundance of sites designated as PAs, Important Bird and Biodivers…
The Impact of Climate Change on Lakes in Northern Europe
2009
In Northern Europe, most lakes are characterized by extended periods of winter ice cover, high spring inflow from snow melt and brown water produced by the transport of dissolved organic carbon (DOC) from the surrounding catchments. In this chapter, the potential impact of climate change on the dynamics of these lakes is addressed by: (i) Describing the historical responses of the lakes to changes in the weather. (ii) Summarizing the results of modelling studies that quantify the impact of future changes in the climate on the lakes and the surrounding catchments. Many existing water quality problems could well be exacerbated by the effects of climatic change. It is therefore important to as…
Regional and Supra-Regional Coherence in Limnological Variabler
2009
Limnologists and water resources managers have traditionally perceived lakes as discrete geographical entities. This has resulted in a tendency for scientific lake studies to concentrate on lakes as individuals, with little connection either to each other or to large-scale driving forces. Since the 1990s, however, a shift in the prevailing paradigm has occurred, with lakes increasingly being seen as responding to regional, rather than local, driving forces. The seminal work on regional coherence in lake behaviour was that of Magnuson et al. (1990), who showed that many features of lakes within the same region respond coherently to drivers such as climate forcing and catchment processes. Fro…
Differential contributions of the two human cerebral hemispheres to action timing
2019
Rhythmic actions benefit from synchronization with external events. Auditory-paced finger tapping studies indicate the two cerebral hemispheres preferentially control different rhythms. It is unclear whether left-lateralized processing of faster rhythms and right-lateralized processing of slower rhythms bases upon hemispheric timing differences that arise in the motor or sensory system or whether asymmetry results from lateralized sensorimotor interactions. We measured fMRI and MEG during symmetric finger tapping, in which fast tapping was defined as auditory-motor synchronization at 2.5 Hz. Slow tapping corresponded to tapping to every fourth auditory beat (0.625 Hz). We demonstrate that t…
Acute Exercise Modulates Pain-induced Response on Sensorimotor Cortex ∼20 Hz Oscillation.
2019
Exercise affects positively on self-reported pain in musculoskeletal pain conditions possibly via top-down pain inhibitory networks. However, the role of cortical activity in these networks is unclear. The aim of the current exploratory study was to investigate the effects of acute exercise on cortical nociceptive processing and specifically the excitability in the human sensorimotor cortex. Five healthy adults (mean age 32.8 years) were recorded with a whole-head 306-channel magnetoencephalography (MEG, Elekta Neuromag® Triux™). Participant’s right hand third fingertip was stimulated electrically with an intracutaneous non-magnetic copper tip electrode before and immediately after an exerc…
Local field potential activity dynamics in response to deep brain stimulation of the subthalamic nucleus in Parkinson's disease
2020
Abstract Local field potentials (LFPs) may afford insight into the mechanisms of action of deep brain stimulation (DBS) and potential feedback signals for adaptive DBS. In Parkinson's disease (PD) DBS of the subthalamic nucleus (STN) suppresses spontaneous activity in the beta band and drives evoked resonant neural activity (ERNA). Here, we investigate how STN LFP activities change over time following the onset and offset of DBS. To this end we recorded LFPs from the STN in 14 PD patients during long (mean: 181.2 s) and short (14.2 s) blocks of continuous stimulation at 130 Hz. LFP activities were evaluated in the temporal and spectral domains. During long stimulation blocks, the frequency …
Dynamical Features of the MAP Kinase Cascade
2017
The MAP kinase cascade is an important signal transduction system in molecular biology for which a lot of mathematical modelling has been done. This paper surveys what has been proved mathematically about the qualitative properties of solutions of the ordinary differential equations arising as models for this biological system. It focuses, in particular, on the issues of multistability and the existence of sustained oscillations. It also gives a concise introduction to the mathematical techniques used in this context, bifurcation theory and geometric singular perturbation theory, as they relate to these specific examples. In addition further directions are presented in which the application…
The Cumulative Effect of Transient Synchrony States on Motor Performance in Parkinson's Disease.
2020
Bursts of beta frequency band activity in the basal ganglia of patients with Parkinson's disease (PD) are associated with impaired motor performance. Here we test in human adults whether small variations in the timing of movement relative to beta bursts have a critical effect on movement velocity and whether the cumulative effects of multiple beta bursts, both locally and across networks, matter.
Multimodal determinants of phase-locked dynamics across deep-superficial hippocampal sublayers during theta oscillations
2020
Theta oscillations play a major role in temporarily defining the hippocampal rate code by translating behavioral sequences into neuronal representations. However, mechanisms constraining phase timing and cell-type-specific phase preference are unknown. Here, we employ computational models tuned with evolutionary algorithms to evaluate phase preference of individual CA1 pyramidal cells recorded in mice and rats not engaged in any particular memory task. We applied unbiased and hypothesis-free approaches to identify effects of intrinsic and synaptic factors, as well as cell morphology, in determining phase preference. We found that perisomatic inhibition delivered by complementary populations…
Extricating New Physics Scenarios at DUNE with High Energy Beams
2017
The proposed Deep Underground Neutrino Experiment (DUNE) utilizes a wide-band on-axis tunable muon-(anti)neutrino beam with a baseline of 1300 km to search for CP violation with high precision. Given the long baseline, DUNE is also sensitive to effects due to non-standard neutrino interactions (NSI) which can interfere with the standard 3-flavor oscillation paradigm. In this Letter, we exploit the tunability of the DUNE neutrino beam over a wide-range of energies and utilize a new theoretical metric to devise an experimental strategy for separating oscillation effects due to NSI from the standard 3-flavor oscillation scenario. Using our metric, we obtain an optimal combination of beam tunes…