Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Fast-Slow Bursters in the Unfolding of a High Codimension Singularity and the Ultra-slow Transitions of Classes.

ABSTRACT: Bursting is a phenomenon found in a variety of physical and biological systems. For example, in neuroscience, bursting is believed to play a key role in the way information is transferred in the nervous system. In this work, we propose a model that, appropriately tuned, can display several types of bursting behaviors. The model contains two subsystems acting at different time scales. For the fast subsystem we use the planar unfolding of a high codimension singularity. In its bifurcation diagram, we locate paths that underlie the right sequence of bifurcations necessary for bursting. The slow subsystem steers the fast one back and forth along these paths leading to bursting behavior. The model is able to produce almost all the classes of bursting predicted for systems with a planar fast subsystem. Transitions between classes can be obtained through an ultra-slow modulation of the model's parameters. A detailed exploration of the parameter space allows predicting possible transitions. This provides a single framework to understand the coexistence of diverse bursting patterns in physical and biological systems or in models.

SUBMITTER: Saggio ML

PROVIDER: S-EPMC5526832 | biostudies-other | 2017 Dec

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Spectral Distortions in Metal-Enhanced Fluorescence: Experimental Evidence for Ultra-Fast and Slow Transitions.

Project description:Metal-enhanced fluorescence (MEF) has become an increasingly important technology in recent years, with thorough research addressing the fundamentals of MEF. In many studies, spectral distortion is observed in the enhanced spectra as compared to free-space fluorescence emission profiles. Despite this observation, very little experimentation has hitherto been undertaken to investigate the mechanistic underpinnings of spectral distortion in MEF. Herein we investigate MEF spectral distortion using Rose Bengal and Fluorescein on silver nanoparticle substrates, subsequently isolating the coupled fluorescence spectrum for a deeper understanding of the spectral modifications. Clear experimental evidence for bathochromic distortion is reported. Remarkably, we also report hypsochromic distortion in one of the first experimental observations of plasmonic coupling to high-energy excited states. Additionally, the coupled fluorescence spectra from other published literature has also been both extracted and examined, and the subsequent spectral distortion reported here. The previously asserted theory of radiative decay rate modification for spectral distortion is discussed in the context of both plasmonic properties as well as fluorophore photophysical characteristics including lifetime and quantum yield. The dual enhancement mechanism of MEF is also explored in the context of spectral distortion. The results and discussion reported herein subsequently provide one of the first comprehensive examinations of spectral distortion in MEF to date.

| S-EPMC8153707 | biostudies-literature

Fast and slow transitions in frontal ensemble activity during flexible sensorimotor behavior.

Project description:The ability to shift between repetitive and goal-directed actions is a hallmark of cognitive control. Previous studies have reported that adaptive shifts in behavior are accompanied by changes of neural activity in frontal cortex. However, neural and behavioral adaptations can occur at multiple time scales, and their relationship remains poorly defined. Here we developed an adaptive sensorimotor decision-making task for head-fixed mice, requiring them to shift flexibly between multiple auditory-motor mappings. Two-photon calcium imaging of secondary motor cortex (M2) revealed different ensemble activity states for each mapping. When adapting to a conditional mapping, transitions in ensemble activity were abrupt and occurred before the recovery of behavioral performance. By contrast, gradual and delayed transitions accompanied shifts toward repetitive responding. These results demonstrate distinct ensemble signatures associated with the start versus end of sensory-guided behavior and suggest that M2 leads in engaging goal-directed response strategies that require sensorimotor associations.

| S-EPMC5003707 | biostudies-literature

Fast association and slow transitions in the interaction between two intrinsically disordered protein domains.

Project description:Proteins that contain long disordered regions are prevalent in the proteome and frequently associated with diseases. However, the mechanisms by which such intrinsically disordered proteins (IDPs) recognize their targets are not well understood. Here, we report the first experimental investigation of the interaction kinetics of the nuclear co-activator binding domain of CREB-binding protein and the activation domain from the p160 transcriptional co-activator for thyroid hormone and retinoid receptors. Both protein domains are intrinsically disordered in the free state and synergistically fold upon binding each other. Using the stopped-flow technique, we found that the binding reaction is fast, with an association rate constant of 3 × 10(7) m(-1) s(-1) at 277 K. Mutation of a conserved buried intermolecular salt bridge showed that electrostatics govern the rapid association. Furthermore, upon mutation of the salt bridge or at high salt concentration, an additional kinetic phase was detected (∼20 and ∼40 s(-1), respectively, at 277 K), suggesting that the salt bridge may steer formation of the productive bimolecular complex in an intramolecular step. Finally, we directly measured slow kinetics for the IDP domains (∼1 s(-1) at 277 K) related to conformational transitions upon binding. Together, the experiments demonstrate that the interaction involves several steps and accumulation of intermediate states. Our data are consistent with an induced fit mechanism, in agreement with previous simulations. We propose that the slow transitions may be a consequence of the multipartner interactions of IDPs.

| S-EPMC3464538 | biostudies-literature

High-Pressure Microfluidics for Ultra-Fast Microbial Phenotyping.

Project description:Here, we present a novel methodology based on high-pressure microfluidics to rapidly perform temperature-based phenotyping of microbial strains from deep-sea environments. The main advantage concerns the multiple on-chip temperature conditions that can be achieved in a single experiment at pressures representative of the deep-sea, overcoming the conventional limitations of large-scale batch metal reactors to conduct fast screening investigations. We monitored the growth of the model strain Thermococcus barophilus over 40 temperature and pressure conditions, without any decompression, in only 1 week, whereas it takes weeks or months with conventional approaches. The results are later compared with data from the literature. An additional example is also shown for a hydrogenotrophic methanogen strain (Methanothermococcus thermolithotrophicus), demonstrating the robustness of the methodology. These microfluidic tools can be used in laboratories to accelerate characterizations of new isolated species, changing the widely accepted paradigm that high-pressure microbiology experiments are time-consuming.

| S-EPMC9168469 | biostudies-literature

Spectral Distortions in Zinc-based Metal-Enhanced Fluorescence Underpinned by Fast and Slow Electronic Transitions.

Project description:Metal-enhanced fluorescence (MEF) is a promising technology with impact in diagnostics, electronics, and sensing. Despite investigation into MEF fundamentals, some properties remain unresearched, notably spectral distortion. To date, publications have described its underpinnings, yet comprehensive analysis is needed, as presented recently for silver films. Herein we expand this description using zinc substrates (ZnNPs). Significant red-edge and blue-edge distortions are reported using Rose Bengal. Radiative decay rate modification is identified as key in amplifying fast/slow electronic transitions by the enhanced emission mechanism. Furthermore, we identify distortion in published studies, bolstering our thinking that spectral distortion is an intrinsic property of MEF.

| S-EPMC7082079 | biostudies-literature

The High-Frequency Signature of Slow and Fast Laboratory Earthquakes.

Project description:Tectonic faults fail through a spectrum of slip modes, ranging from slow aseismic creep to rapid slip during earthquakes. Understanding the seismic radiation emitted during these slip modes is key for advancing earthquake science and earthquake hazard assessment. In this work, we use laboratory friction experiments instrumented with ultrasonic sensors to document the seismic radiation properties of slow and fast laboratory earthquakes. Stick-slip experiments were conducted at a constant loading rate of 8 μm/s and the normal stress was systematically increased from 7 to 15 MPa. We produced a full spectrum of slip modes by modulating the loading stiffness in tandem with the fault zone normal stress. Acoustic emission data were recorded continuously at 5 MHz. We demonstrate that the full continuum of slip modes radiate measurable high-frequency energy between 100 and 500 kHz, including the slowest events that have peak fault slip rates <100 μm/s. The peak amplitude of the high-frequency time-domain signals scales systematically with fault slip velocity. Stable sliding experiments further support the connection between fault slip rate and high-frequency radiation. Experiments demonstrate that the origin of the high-frequency energy is fundamentally linked to changes in fault slip rate, shear strain, and breaking of contact junctions within the fault gouge. Our results suggest that having measurements close to the fault zone may be key for documenting seismic radiation properties and fully understanding the connection between different slip modes.

| S-EPMC9287021 | biostudies-literature

Ultra-fast transcriptional responses in plants

Project description:Transcriptome of plants exposed to 0, 20 and 60 sec light stress was analyzed using Illumina HiSeq2000. We found that mRNA accumulation of more than 700 transcripts in plants occurs as early as 20-60 sec following light stress application

2016-12-06 | GSE60865 | GEO

Demography: Fast and Slow.

Project description:Scientific ideas on the human population tend to be rooted in a "slow demography" paradigm, which emphasizes an inertial, predictable, self-contained view of population dynamics, mostly dependent on fertility and mortality. Yet, demography can also move fast. At the country level, it is crucial to empirically assess how fast demography moves by taking migratory movements into account, in addition to fertility and mortality. We discuss these ideas and present new estimates of the speed of population change, that is, country-level population turnover rates, as well as the share of turnover due to migration, for all countries in the world with available data between 1990 and 2020. Population turnover is inversely related to population size and development, and migratory movements tend to become important factors in shaping demography for both small and highly developed countries. Longitudinally, we analyze annual turnover data for Italy and Germany, documenting the changing speed of population change over time and its determinants. Accepting the "fast and slow" demography perspective has several implications for science and policy, which we discuss.

| S-EPMC9305154 | biostudies-literature

slow/fast muscle with or without amplification

Project description:Comparing the gene expression profiles of slow and fast skeletal muscle (soleus VS FDB) with either amplified RNA (cRNA probes) or original mRNA (cDNA probes). The fidelity of mRNA amplification method in identifying the gene expression profiles of our samples were validated. Keywords: cell type comparison

2007-01-18 | GSE6654 | GEO

Ultra-Fast High-Precision Metallic Nanoparticle Synthesis using Laser-Accelerated Protons.

Project description:Laser-driven proton acceleration, as produced during the interaction of a high-intensity (I?>?1 × 1018?W/cm2), short pulse (<1?ps) laser with a solid target, is a prosperous field of endeavor for manifold applications in different domains, including astrophysics, biomedicine and materials science. These emerging applications benefit from the unique features of the laser-accelerated particles such as short duration, intense flux and energy versatility, which allow obtaining unprecedented temperature and pressure conditions. In this paper, we show that laser-driven protons are perfectly suited for producing, in a single sub-ns laser pulse, metallic nanocrystals with tunable diameter ranging from tens to hundreds of nm and very high precision. Our method relies on the intense and very quick proton energy deposition, which induces in a bulk material an explosive boiling and produces nanocrystals that aggregate in a plasma plume composed by atoms detached from the proton-irradiated surface. The properties of the obtained particles depend on the deposited proton energy and on the duration of the thermodynamical process. Suitably controlling the irradiated dose allows fabricating nanocrystals of a specific size with low polydispersity that can easily be isolated in order to obtain a monodisperse nanocrystal solution. Molecular Dynamics simulations confirm our experimental results.

| S-EPMC7293332 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data