18 research outputs found
Dynamics of a stochastic excitable system with slowly adapting feedback
We study an excitable active rotator with slowly adapting nonlinear feedback
and noise. Depending on the adaptation and the noise level, this system may
display noise-induced spiking, noise-perturbed oscillations, or stochastic
busting. We show how the system exhibits transitions between these dynamical
regimes, as well as how one can enhance or suppress the coherence resonance, or
effectively control the features of the stochastic bursting. The setup can be
considered as a paradigmatic model for a neuron with a slow recovery variable
or, more generally, as an excitable system under the influence of a nonlinear
control mechanism. We employ a multiple timescale approach that combines the
classical adiabatic elimination with averaging of rapid oscillations and
stochastic averaging of noise-induced fluctuations by a corresponding
stationary Fokker-Planck equation. This allows us to perform a numerical
bifurcation analysis of a reduced slow system and to determine the parameter
regions associated with different types of dynamics. In particular, we
demonstrate the existence of a region of bistability, where the noise-induced
switching between a stationary and an oscillatory regime gives rise to
stochastic bursting
GrassPlot v. 2.00 – first update on the database of multi-scale plant diversity in Palaearctic grasslands
Abstract: GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phyto- coenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems
Indicateurs de biodiversité dans les exploitations agricoles biologiques et conventionnelles des Vallées et Coteaux de Gascogne, cas d’étude français du projet européen BIOBIO:Biodiversity indicators in organic and conventional farming systems: main results from the European project BIOBIO
Mechanisms and clinical relevance of the bidirectional relationship of viral infections with metabolic diseases
Interplay management: enhancing environmental policy integration among international institutions
Environmental Policy Integration, International Environmental Governance, Institutional interaction, Institutional interplay, International environmental policy, International institutions, Interplay management, Multilateral Environmental Agreements,