Information transmission and noise correlation in continuous and bursty signaling systems

2020 ◽  
pp. 2150015
Author(s):  
Xiyan Yang ◽  
Yahao Wu ◽  
Jiajun Zhang
Keyword(s):  
Information Transmission ◽  
Intrinsic Noise ◽  
Correlated Noise ◽  
Extrinsic Noise ◽  
Signaling Systems ◽  
Signaling Mechanisms ◽  
Multiple Receptors ◽  
Total Noise ◽  
Two Component ◽  
The Relationship

Biological cells sense external concentrations via stochastic receptor signals and respond by regulating the expression of target proteins. Two main signaling mechanisms have been found to encode signal molecular concentrations: continuous modulation (CM), where the receptor signals continuously whenever a ligand is bound, and bursty modulation (BM), where the receptor signals shortly and with fixed size only upon the binding of a ligand. The two mechanisms are often subject to noise which influences the reliability of information transmission. However, how the relationship between noise and information transmission works in the two mechanisms is still unanswered. Here, we analyze a two-component signaling system with multiple receptors which can produce continuous or bursty signals, and decompose the total noise into three terms: intrinsic noise, extrinsic noise and correlated noise. Based on the obtained formulas, we study the information transmission and noise correlations in two signaling mechanisms. We find that (1) the intrinsic noise of BM is always not less than that of CM, whereas the correlation noise of the former is negative and that of the latter is zero; (2) the extrinsic noise of BM can be higher or lower than that of CM, or the former equals the latter, which depends on the mean duration ratio of the receptors at active and inactive states; and (1) the relationship between output noise and mutual information is inversely proportional in the two signaling mechanisms. Our results reveal the correlation between information transmission and noise which can be used to analyze the dynamics of two-component systems.

scholarly journals New Approach to Quantitative Analysis of Two-Component Polymer Systems by Infrared Spectroscopy

1996 ◽  
Vol 50 (6) ◽  
pp. 774-780 ◽  
Author(s):  
K. C. Cole ◽  
Y. Thomas ◽  
E. Pellerin ◽  
M. M. Dumoulin ◽  
R. M. Paroli
Keyword(s):  
Infrared Spectroscopy ◽  
Quantitative Analysis ◽  
Weight Fraction ◽  
Polymer Systems ◽  
Near Ir ◽  
Miscible Blends ◽  
Two Component ◽  
New Treatment ◽  
Two Peaks ◽  
The Relationship

A new treatment is proposed for quantitative analysis of two-component polymer systems by infrared spectroscopy. Like much previous work, it is based on a ratio involving two peaks in the same spectrum. The relationship between such a ratio and the concentration of a given polymer is inherently nonlinear. It is shown that this nonlinearity can be well described by a simple equation derived from the laws of optical transmission. This equation has the form χ1 = m1 + m2 R/(1 + m3 R), where χ1 is the weight fraction of polymer 1, the mi are adjustable coefficients, and the ratio R is equal to Aa/( Aa + Ab). The quantities Aa and Ab are the absorbances (peak heights or areas) at two frequencies a and b of which the first is associated mainly with polymer 1 and the second with polymer 2. This equation has been applied to various peak combinations in spectra of miscible blends of poly(phenylene ether) with polystyrene (both mid-IR and near-IR data) and immiscible blends of polypropylene with polyethylene (mid-IR data). It is shown that the equation is valid in all cases, covering the full concentration range from 0 to 100% even when the peaks used for the analysis involve absorption by both polymers. It is therefore believed to be of broad general usefulness for the analysis of polymer blends and copolymers.

scholarly journals Antidepressants and Circadian Rhythm: Exploring Their Bidirectional Interaction for the Treatment of Depression

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1975
Author(s):  
Soraia Silva ◽  
Joana Bicker ◽  
Amílcar Falcão ◽  
Ana Fortuna
Keyword(s):  
Circadian Rhythms ◽  
Intracellular Signaling ◽  
Scientific Evidence ◽  
Antidepressant Drugs ◽  
Positive Influence ◽  
Drug Dosing ◽  
Signaling Systems ◽  
Treatment Of Depression ◽  
Target Molecules ◽  
The Relationship

Scientific evidence that circadian rhythms affect pharmacokinetics and pharmacodynamics has highlighted the importance of drug dosing-time. Circadian oscillations alter drug absorption, distribution, metabolism, and excretion (ADME) as well as intracellular signaling systems, target molecules (e.g., receptors, transporters, and enzymes), and gene transcription. Although several antidepressant drugs are clinically available, less than 50% of depressed patients respond to first-line pharmacological treatments. Chronotherapeutic approaches to enhance the effectiveness of antidepressants are not completely known. Even so, experimental results found until this day suggest a positive influence of drug dosing-time on the efficacy of depression therapy. On the other hand, antidepressants have also demonstrated to modulate circadian rhythmicity and sleep–wake cycles. This review aims to evidence the potential of chronotherapy to improve the efficacy and/or safety of antidepressants. It includes pre-clinical and clinical studies that demonstrate the relevance of determining the most appropriate time of administration for antidepressant drugs. In parallel, their positive influence on the resynchronization of disrupted circadian rhythms is also herein discussed. It is expected that this review will promote the investigation of chronotherapy for the treatment of depression, contribute to a better understanding of the relationship between antidepressants and circadian rhythms, and consequently promote the development of new therapeutics.

The level of cytoskeleton remodeling proteins in the blood serum and the expression of their mRNA in the tumor tissue in metastasis of the larynx and hypopharynx cancer

2021 ◽  
Author(s):  
Gelena Kakurina ◽  
Olga V Cheremisina ◽  
Elena E Sereda ◽  
Elena S Kolegova ◽  
Irina V Kondakova ◽  
...  
Keyword(s):  
Serum Level ◽  
Blood Serum ◽  
Mrna Expression ◽  
Tumor Tissue ◽  
Mrna Level ◽  
Actin Binding ◽  
Tissue Samples ◽  
Signaling Systems ◽  
Cytoskeleton Remodeling ◽  
The Relationship

Abstract Purpose: Actin-binding proteins (ABPs) and various signaling systems are involved in the metastasis of squamous cell carcinoma of the larynx and hypopharynx (SCCLH). The clinical significance of these proteins has not yet been determined. We analyzed the relationship between the mRNA level of cofilin 1 (CFL1), profilin 1 (PFN1), adenylyl cyclase-associated protein 1 (CAP1), SNAIL and RND3 with metastasis in the SCCLH tissue. The serum level of the listed ABPs was estimated and the relationship of them with the expression of the corresponding mRNA was carried out. Materials and methods: The expression level of ABPs mRNA was measured by real-time RT-PCR in paired tissue samples taken from 54 patients with SCCLH (T 1-4 N 0-1 M 0 ). Expression analysis was performed using the 2 - ΔΔ CT method. The level of ABPs in the blood serum was measured by ELISA. Statistical analysis was carried out using the SPSS Statistica 20.0 software package. Results: The mRNA expression of the studied genes in tumor tissue of patients with SCCLH T 1-3 N 0 M 0 and T 2-4 N 1-2 M 0 did not differ significantly. High expression of RND3 mRNA was accompanied by an increase in mRNA expression of all studied ABPs. In the blood serum of T 2-4 N 1-2 M 0 patients the level of PFN1 was significantly lower by 21% and the level of CAP1 was higher by 75% compared with the group of patients with T 1-4 N 0 M 0 stage. Conclusion: According to our data RND3 is involved in the regulation of molecular cascades SCCLH metastasis. PFN1 and CAP1 serum level can be a good classifier of metastases in patients with SCCLH.

Application of spectral analysis for determine the phase shift of signals with equal amplitudes using full-wave transformation when measuring the characteristics of weapons

2021 ◽  
pp. 12-23
Author(s):  
S. Tyshko ◽  
O. Lavrut ◽  
V. Smolar ◽  
O. Zabula ◽  
Yu. Chernichenko
Keyword(s):  
Spectral Analysis ◽  
Phase Shift ◽  
Information Transmission ◽  
Measurement Problem ◽  
Wave Transformation ◽  
Measuring Systems ◽  
Transmission Channels ◽  
Harmonic Signals ◽  
Full Wave ◽  
The Relationship

The article defines the list of technical characteristics of armaments and military equipment (ARM), the value of which is measured using phase methods. An analysis of known methods that have found wide application in measuring technology, which is designed to determine the technical characteristics associated with the measurement of phase shift during the development, manufacture and operation of weapons. Based on this analysis, it was determined that the measuring systems are designed to determine the phase shift of two harmonic signals in their composition have two channels of information transmission. This architecture of the implementation of measuring systems leads to the fact that a significant impact on the accuracy of the proposed measurement problem, makes a component of the error due to the phase symmetry of the signal transmission channels, as well as internal and external noise. As an alternative approach to solving the measurement problem of determining the phase shift of two harmonic signals, which will significantly reduce the error component due to phase asymmetry of information transmission channels, it is proposed to use the signal obtained by summing harmonic signals after full-wave transformation followed by spectral analysis. In order to implement the above approach, a measurement problem was set to determine the phase shift of two harmonic signals, using spectral analysis of the signal obtained by summing the harmonic signals after their full-wave transformation. A list of assumptions required for the synthesis of analytical relations that establish the relationship between the spectra of phases and amplitudes (power) of the signal obtained by summing harmonic signals after their full-wave transformation and phase shift of two harmonic signals. Analytical relationships are proposed that establish the relationship between the above characteristics. It is shown that the values of the spectrum of phases and amplitudes, which are calculated using the proposed expressions, differ from the values obtained in the calculations using the Fourier series coefficients, not more than 0.1%.

On the realizability of pressure–strain closures

2014 ◽  
Vol 755 ◽  
pp. 535-560 ◽  
Author(s):  
Aashwin A. Mishra ◽  
Sharath S. Girimaji
Keyword(s):  
Statistical Models ◽  
Flow Stability ◽  
Mean Flow ◽  
Model Formulation ◽  
Closure Model ◽  
Two Component ◽  
The Mean ◽  
The Relationship ◽  
Rapid Pressure ◽  
Domain Of Validity

AbstractThe realizability condition for statistical models of turbulence is augmented to ensure that not only is the Reynolds stress tensor positive semi-definite, but the process of its evolution is physically attainable as well. The mathematical constraints due to this process realizability requirement on the rapid pressure strain correlation are derived. The resulting constraints reveal important limits on the inter-component energy transfer and the consequent flow stability characteristics, as a function of the mean flow. For planar mean flows, the realizability constraints are most stringent for the case of purely sheared flows rather than elliptic flows. The relationship between the constraints and flow stability is explained. Process realizability leads to closure model guidance not only at the two-component (2C) limit of turbulence (as in the classical realizability approach) but throughout the anisotropy space. Consequently, the domain of validity and applicability of current models can be clearly identified for different mean flows. A simple framework for incorporating these process realizability constraints in model formulation is outlined.

scholarly journals Correlated activity favors synergistic processing in local cortical networks in vitro at synaptically relevant timescales

2020 ◽  
Vol 4 (3) ◽  
pp. 678-697
Author(s):  
Samantha P. Sherrill ◽  
Nicholas M. Timme ◽  
John M. Beggs ◽  
Ehren L. Newman
Keyword(s):  
Information Processing ◽  
Mutual Information ◽  
Information Transmission ◽  
Cortical Circuits ◽  
Correlated Activity ◽  
Neural Information ◽  
Neural Information Processing ◽  
The Relationship ◽  
Information Values

Neural information processing is widely understood to depend on correlations in neuronal activity. However, whether correlation is favorable or not is contentious. Here, we sought to determine how correlated activity and information processing are related in cortical circuits. Using recordings of hundreds of spiking neurons in organotypic cultures of mouse neocortex, we asked whether mutual information between neurons that feed into a common third neuron increased synergistic information processing by the receiving neuron. We found that mutual information and synergistic processing were positively related at synaptic timescales (0.05–14 ms), where mutual information values were low. This effect was mediated by the increase in information transmission—of which synergistic processing is a component—that resulted as mutual information grew. However, at extrasynaptic windows (up to 3,000 ms), where mutual information values were high, the relationship between mutual information and synergistic processing became negative. In this regime, greater mutual information resulted in a disproportionate increase in redundancy relative to information transmission. These results indicate that the emergence of synergistic processing from correlated activity differs according to timescale and correlation regime. In a low-correlation regime, synergistic processing increases with greater correlation, and in a high-correlation regime, synergistic processing decreases with greater correlation.

scholarly journals Feature Selection in Simple Neurons: How Coding Depends on Spiking Dynamics

2010 ◽  
Vol 22 (3) ◽  
pp. 581-598 ◽  
Author(s):  
Michael Famulare ◽  
Adrienne Fairhall
Keyword(s):  
Feature Selection ◽  
Information Transmission ◽  
Nonlinear Function ◽  
Sensory Systems ◽  
Statistical Characteristics ◽  
Neuron Models ◽  
Linear Filters ◽  
Feature Selectivity ◽  
Coding Strategy ◽  
The Relationship

The relationship between a neuron's complex inputs and its spiking output defines the neuron's coding strategy. This is frequently and effectively modeled phenomenologically by one or more linear filters that extract the components of the stimulus that are relevant for triggering spikes and a nonlinear function that relates stimulus to firing probability. In many sensory systems, these two components of the coding strategy are found to adapt to changes in the statistics of the inputs in such a way as to improve information transmission. Here, we show for two simple neuron models how feature selectivity as captured by the spike-triggered average depends on both the parameters of the model and the statistical characteristics of the input.

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