The role of dorsal respiratory group neurons studied with cross-correlation in the decerebrate rat

1998 ◽  
Vol 121 (1) ◽  
pp. 29-34 ◽  
Author(s):  
G.-F. Tian ◽  
J. Duffin
Keyword(s):  
Cross Correlation ◽  
Dorsal Respiratory Group ◽  
Decerebrate Rat

QUANTIFYING STOCHASTIC RESONANCE IN A SINGLE THRESHOLD DETECTOR FOR RANDOM APERIODIC SIGNALS

2004 ◽  
Vol 04 (02) ◽  
pp. L247-L265 ◽  
Author(s):  
ARUNEEMA DAS ◽  
N. G. STOCKS ◽  
A. NIKITIN ◽  
E. L. HINES
Keyword(s):  
Stochastic Resonance ◽  
Cross Correlation ◽  
Signal To Noise Ratio ◽  
Probability Distributions ◽  
Probability Density Functions ◽  
Surprising Result ◽  
Threshold Detector ◽  
Gaussian Form ◽  
Aperiodic Signal

We explore stochastic resonance (SR) effects in a single comparator (threshold detector) driven by either a Gaussian or exponentially distributed aperiodic signal. The behaviour of different performance measures, namely the cross-correlation coefficient (CCC), signal-to-noise ratio (SNR) and mutual information, I, has been investigated. The signals were added to Gaussian noise before being passed through the threshold detector. For the two signals tested, we observe the perhaps surprising result that the SNR never displays SR. However, SR is displayed by both the CCC and I for Gaussian signals. For exponential signals SR is not displayed by any of the measures. By generating signals whose probability distributions have the generalized Gaussian form Ae-|βx|n it is possible to demonstrate that SR ceases to occur if n<1.7. We conclude that SR is only observable in threshold based systems for certain types of aperiodic signal. Specifically, SR is not expected to occur for signals whose probability density functions have long, slowly decaying, tails. We discuss the implication of these results for the role of SR in biological sensory systems.

Prostaglandins mediate skeletal muscle arteriole dilation in hyperdynamic bacteremia

1990 ◽  
Vol 259 (3) ◽  
pp. H728-H734
Author(s):  
H. G. Cryer ◽  
R. N. Garrison ◽  
P. D. Harris ◽  
B. H. Greenwald ◽  
N. L. Alsip
Keyword(s):  
Skeletal Muscle ◽  
Topical Application ◽  
Serotonin Receptors ◽  
Cremaster Muscle ◽  
Synthesis Inhibitor ◽  
E Coli ◽  
Decerebrate Rat ◽  
Prostaglandin Synthesis Inhibitor ◽  
Baseline Values

Live Escherichia coli bacteremia during the high cardiac output (hyperdynamic) phase of sepsis causes constriction of large arterioles but dilation of small arterioles in skeletal muscle. This study examines the role of dilator prostaglandins, serotonin, and histamine in these differential microvascular responses in the decerebrate rat that avoids the effects of drug anesthesia. Topical application of meclofenamate, a prostaglandin synthesis inhibitor, to the cremaster muscle 60 min after induction of E. coli bacteremia enhanced the constriction of large arterioles from 20 +/- 8 to 46 +/- 9% less than baseline and blunted the dilation of small arterioles from 39 +/- 9 to 17 +/- 7% above baseline values in the cremaster microcirculation. Induction of E. coli bacteremia after pretreatment of the cremaster with meclofenamate constricted large arterioles to 40 +/- 4% less than baseline and small arterioles to 31 +/- 4% less than baseline. This indicates that prostaglandins initiate small arteriole dilation in response to E. coli, but some other dilator factor is activated by prostaglandins to maintain small arteriole dilation during E. coli bacteremia. Topical application of cyproheptadine, an antagonist of both histamine and serotonin receptors, to the cremaster muscle did not alter the E. coli-induced constriction of large arterioles or the dilation of small arterioles in the cremaster microcirculation.

scholarly journals Current Correlations in a Quantum Dot Ring: A Role of Quantum Interference

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 527 ◽  
Author(s):  
Bogdan R. Bułka ◽  
Jakub Łuczak
Keyword(s):  
Correlation Functions ◽  
Quantum Interference ◽  
Cross Correlation ◽  
Destructive Interference ◽  
Quantum Interference Effect ◽  
Auto Correlation ◽  
Current Correlation ◽  
Relevant Role ◽  
Opposite Chirality

We present studies of the electron transport and circular currents induced by the bias voltage and the magnetic flux threading a ring of three quantum dots coupled with two electrodes. Quantum interference of electron waves passing through the states with opposite chirality plays a relevant role in transport, where one can observe Fano resonance with destructive interference. The quantum interference effect is quantitatively described by local bond currents and their correlation functions. Fluctuations of the transport current are characterized by the Lesovik formula for the shot noise, which is a composition of the bond current correlation functions. In the presence of circular currents, the cross-correlation of the bond currents can be very large, but it is negative and compensates for the large positive auto-correlation functions.

scholarly journals The role of galaxies and AGN in reionizing the IGM – III. IGM–galaxy cross-correlations at z ∼ 6 from eight quasar fields with DEIMOS and MUSE

2020 ◽  
Vol 494 (2) ◽  
pp. 1560-1578
Author(s):  
Romain A Meyer ◽  
Koki Kakiichi ◽  
Sarah E I Bosman ◽  
Richard S Ellis ◽  
Nicolas Laporte ◽  
...  
Keyword(s):  
Correlation Function ◽  
Cross Correlation ◽  
Mean Free Path ◽  
Lyman Break Galaxies ◽  
The Galaxy ◽  
Cross Correlations ◽  
The Mean ◽  
Improved Model ◽  
First Time

ABSTRACT We present improved results of the measurement of the correlation between galaxies and the intergalactic medium transmission at the end of reionization. We have gathered a sample of 13 spectroscopically confirmed Lyman-break galaxies (LBGs) and 21 Lyman-α emitters (LAEs) at angular separations 20 arcsec ≲ θ ≲ 10 arcmin (∼0.1–4 pMpc at z ∼ 6) from the sightlines to eight background z ≳ 6 quasars. We report for the first time the detection of an excess of Lyman-α transmission spikes at ∼10–60 cMpc from LAEs (3.2σ) and LBGs (1.9σ). We interpret the data with an improved model of the galaxy–Lyman-α transmission and two-point cross-correlations, which includes the enhanced photoionization due to clustered faint sources, enhanced gas densities around the central bright objects and spatial variations of the mean free path. The observed LAE(LBG)–Lyman-α transmission spike two-point cross-correlation function (2PCCF) constrains the luminosity-averaged escape fraction of all galaxies contributing to reionization to $\langle f_{\rm esc} \rangle _{M_{\rm UV}\lt -12} = 0.14_{-0.05}^{+0.28}\, (0.23_{-0.12}^{+0.46})$. We investigate if the 2PCCF measurement can determine whether bright or faint galaxies are the dominant contributors to reionization. Our results show that a contribution from faint galaxies ($M_{\rm UV} \gt -20 \, (2\sigma)$) is necessary to reproduce the observed 2PCCF and that reionization might be driven by different sub-populations around LBGs and LAEs at z ∼ 6.

Role of upper cervical inspiratory neurons studied by cross-correlation in the cat

1992 ◽  
Vol 90 (1) ◽  
Author(s):  
M.A. Douse ◽  
J. Duffin ◽  
D. Brooks ◽  
L. Fedorko
Keyword(s):  
Cross Correlation ◽  
Inspiratory Neurons ◽  
Upper Cervical

The 2016 Mw 7.8 Kaikoura earthquake and its relationship to tremors.

2020 ◽  
Author(s):  
Pierre Romanet ◽  
Florent Aden-Antoniow ◽  
Satoshi Ide
Keyword(s):  
Cross Correlation ◽  
Seismic Energy ◽  
Slow Slip ◽  
Unexpected Events ◽  
Slow Slip Event ◽  
Slow Earthquakes ◽  
Slip Event ◽  
Kaikoura Earthquake ◽  
The Relationship

&lt;p&gt;The relationship between slow earthquake and regular earthquake is fundamental question in seismology. It was already shown that some slow slip event may have led to some megathrust event. In return, passing surface wave from earthquake may also trigger tremors and slow slip event. Documenting these possible triggering effects between slow and fast events is of primary importance to understand them.&lt;/p&gt;&lt;p&gt;In this study we will focus more particularly on Marlborough region, in a region that was subject to the Mw 7.8 2016 Kaikoura earthquake. Two years before Kaikoura earthquake, we observed a Northeast to Southwest migration of tremors, getting closer to the hypocenter of Kaikoura earthquake. Despite being speculative, this may indicate that a slow slip event is happening shortly before Kaikoura earthquake, which is also supported by a small signal in two GPS stations nearby. After the earthquake, the rate of tremors increased in the region. Studying the relationship between tremors and the Kaikoura earthquake may provide some information on the role of the subduction in the region, as well as provide a new documented interaction of slow earthquakes with a crustal earthquake.&lt;/p&gt;&lt;p&gt;To detect and locate tremors, we use broadband and shortband velocity traces from the GeoNet network. The traces are bandpass filtered between 2-8Hz, and transform into envelope. Then we apply a classic cross-correlation technic to detect and locate the events. To remove unexpected events (i.e.: earthquakes), we used a criteria base on seismic energy and duration. Finally, we manually check each velocity traces and spectrograms.&lt;/p&gt;

scholarly journals Involvement of Thalamus in Initiation of Epileptic Seizures Induced by Pilocarpine in Mice

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Yong-Hua Li ◽  
Jia-Jia Li ◽  
Qin-Chi Lu ◽  
Hai-Qing Gong ◽  
Pei-Ji Liang ◽  
...  
Keyword(s):  
Information Flow ◽  
Cross Correlation ◽  
Flow Direction ◽  
Epileptic Seizures ◽  
Seizure Onset ◽  
Parafascicular Nucleus ◽  
Two Measures ◽  
Initiation Period ◽  
Variation Tendency

Studies have suggested that thalamus is involved in temporal lobe epilepsy, but the role of thalamus is still unclear. We obtained local filed potentials (LFPs) and single-unit activities from CA1 of hippocampus and parafascicular nucleus of thalamus during the development of epileptic seizures induced by pilocarpine in mice. Two measures, redundancy and directionality index, were used to analyze the electrophysiological characters of neuronal activities and the information flow between thalamus and hippocampus. We found that LFPs became more regular during the seizure in both hippocampus and thalamus, and in some cases LFPs showed a transient disorder at seizure onset. The variation tendency of the peak values of cross-correlation function between neurons matched the variation tendency of the redundancy of LFPs. The information tended to flow from thalamus to hippocampus during seizure initiation period no matter what the information flow direction was before the seizure. In some cases the information flow was symmetrically bidirectional, but none was found in which the information flowed from hippocampus to thalamus during the seizure initiation period. In addition, inactivation of thalamus by tetrodotoxin (TTX) resulted in a suppression of seizures. These results suggest that thalamus may play an important role in the initiation of epileptic seizures.

scholarly journals Role of Viscosity in Deviations from the Nernst-Einstein Relation

2019 ◽  
Author(s):  
Yunqi Shao ◽  
Keisuke Shigenobu ◽  
Masayoshi Watanabe ◽  
Chao Zhang
Keyword(s):  
Molecular Dynamics ◽  
Periodic Boundary ◽  
Cross Correlation ◽  
Finite Size ◽  
Periodic Boundary Conditions ◽  
Finite Size Effect ◽  
Einstein Relation ◽  
Experimental Measurements ◽  
Dynamics Simulations

<div><div><div><p>Deviations from the Nernst-Einstein rela- tion are commonly attributed to ion-ion (cross)correlation and ion-pairing. Despite the fact that these deviations can be quantified by either experimental measurements or molecular dynamics simulations, there is no rule of thumb to tell the extent of deviations. Here, we show that deviations from the Nernst-Einstein relation scale linearly with the inverse viscosity by exploring the finite-size effect in periodic boundary conditions. This conclusion is in accord with published experimental results of ionic liquids.</p></div></div></div>

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