scholarly journals Signal Fluctuations and the Information Transmission Rates in Binary Communication Channels

2020 ◽  
Author(s):  
Agnieszka Pregowska
Keyword(s):  
Information Transmission ◽  
Information Sources ◽  
Transition Probabilities ◽  
Transmission Rate ◽  
Spike Trains ◽  
Noisy Environment ◽  
Transmission Rates ◽  
Stationary Stochastic Processes ◽  
System Information ◽  
Transmission Information

(1) Background: In nervous system information is conveyed by a sequence of action potentials, called spikes-trains. As MacKay and McCulloch proposed, spike-trains can be represented as bits sequences coming from Information Sources. Previously, we studied relations between Information Transmission Rates (ITR) carried out by the spikes, their correlations, and frequencies. Here, we concentrate on the problem of how spikes fluctuations affect ITR. (2) Methods: The Information Theory Method developed by Shannon is applied. Information Sources are modeled as stationary stochastic processes. We assume such sources as two states Markov processes. As a spike-trains' fluctuation measure, we consider the Standard Deviation sigma, which, in fact, measures average fluctuation of spikes around the average spike frequency. (3) Results: We found that character of ITR and signal fluctuations relation strongly depends on the parameter s which is a sum of transitions probabilities from no spike state to spike state and vice versa. It turned out that for smaller s (s<1) the quotient ITR\sigma has a maximum and can tend to zero depending on transition probabilities. While for s large enough (1<s) the ITR\sigma is separated from 0 for each s. Similar behavior was observed also when we replaced Shannon entropy terms in Markov entropy formula by their approximation with polynomials. We also show that the ITR quotient by Variance behaves in a completely different way. (4) Conclusions: Our results show that for large transition parameter s the Information Transmission Rate by sigma will never decrease to zero. Specifically, for 1<s<1.7 the ITR will be always, independently on transition probabilities which form this s, above the level of fluctuations, i.e. in this case we have sigma<ITR. Thus, we conclude that in a more noisy environment, to get appropriate reliability and efficiency of transmission, Information Sources with higher tendency of transition from the state no spike to spike state and vice versa should be applied.

scholarly journals Signal Fluctuations and the Information Transmission Rates in Binary Communication Channels

Entropy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 92
Author(s):  
Agnieszka Pregowska
Keyword(s):  
Information Transmission ◽  
Action Potentials ◽  
Transition Probabilities ◽  
Transmission Rate ◽  
Spike Trains ◽  
Learning Mechanisms ◽  
Transmission Rates ◽  
Stationary Stochastic Processes ◽  
System Information ◽  
Selection Of

In the nervous system, information is conveyed by sequence of action potentials, called spikes-trains. As MacKay and McCulloch suggested, spike-trains can be represented as bits sequences coming from Information Sources (IS). Previously, we studied relations between spikes’ Information Transmission Rates (ITR) and their correlations, and frequencies. Now, I concentrate on the problem of how spikes fluctuations affect ITR. The IS are typically modeled as stationary stochastic processes, which I consider here as two-state Markov processes. As a spike-trains’ fluctuation measure, I assume the standard deviation σ, which measures the average fluctuation of spikes around the average spike frequency. I found that the character of ITR and signal fluctuations relation strongly depends on the parameter s being a sum of transitions probabilities from a no spike state to spike state. The estimate of the Information Transmission Rate was found by expressions depending on the values of signal fluctuations and parameter s. It turned out that for smaller s<1, the quotient ITRσ has a maximum and can tend to zero depending on transition probabilities, while for 1<s, the ITRσ is separated from 0. Additionally, it was also shown that ITR quotient by variance behaves in a completely different way. Similar behavior was observed when classical Shannon entropy terms in the Markov entropy formula are replaced by their approximation with polynomials. My results suggest that in a noisier environment (1<s), to get appropriate reliability and efficiency of transmission, IS with higher tendency of transition from the no spike to spike state should be applied. Such selection of appropriate parameters plays an important role in designing learning mechanisms to obtain networks with higher performance.

scholarly journals How Far can Neural Correlations Reduce Uncertainty? Comparison of Information Transmission Rates for Markov and Bernoulli Processes

2019 ◽  
Vol 29 (08) ◽  
pp. 1950003 ◽  
Author(s):  
Agnieszka Pregowska ◽  
Ehud Kaplan ◽  
Janusz Szczepanski
Keyword(s):  
Information Transmission ◽  
Crucial Role ◽  
Transition Probabilities ◽  
Temporal Code ◽  
Rate Code ◽  
Neural Codes ◽  
Loss Of Information ◽  
Transmission Rates ◽  
Firing Rates ◽  
Markov Source

The nature of neural codes is central to neuroscience. Do neurons encode information through relatively slow changes in the firing rates of individual spikes (rate code) or by the precise timing of every spike (temporal code)? Here we compare the loss of information due to correlations for these two possible neural codes. The essence of Shannon’s definition of information is to combine information with uncertainty: the higher the uncertainty of a given event, the more information is conveyed by that event. Correlations can reduce uncertainty or the amount of information, but by how much? In this paper we address this question by a direct comparison of the information per symbol conveyed by the words coming from a binary Markov source (temporal code) with the information per symbol coming from the corresponding Bernoulli source (uncorrelated, rate code). In a previous paper we found that a crucial role in the relation between information transmission rates (ITRs) and firing rates is played by a parameter [Formula: see text], which is the sum of transition probabilities from the no-spike state to the spike state and vice versa. We found that in this case too a crucial role is played by the same parameter [Formula: see text]. We calculated the maximal and minimal bounds of the quotient of ITRs for these sources. Next, making use of the entropy grouping axiom, we determined the loss of information in a Markov source compared with the information in the corresponding Bernoulli source for a given word length. Our results show that in the case of correlated signals the loss of information is relatively small, and thus temporal codes, which are more energetically efficient, can replace rate codes effectively. These results were confirmed by experiments.

Information theoretic analysis of dynamical encoding by filiform mechanoreceptors in the cricket cercal system

1996 ◽  
Vol 75 (4) ◽  
pp. 1365-1376 ◽  
Author(s):  
J. C. Roddey ◽  
G. A. Jacobs
Keyword(s):  
Information Transmission ◽  
Transmission Rate ◽  
Spike Trains ◽  
Integration Time ◽  
Median Frequency ◽  
Hair Length ◽  
Information Theoretic ◽  
Response Properties ◽  
Stimulus Response ◽  
Receptor Cells

1. The stimulus/response properties of 20 mechanosensory receptors in the cricket cercal sensory system were studied using electrophysiological techniques. These receptors innervated filiform hairs of various lengths and directional selectivities. Previous studies have characterized the sensitivity of such cells to the direction of air currents and to the amplitude of sinusoidal stimuli. In the experiments reported here, the quantity and quality of information encoded in the receptors' elicited responses about the dynamics of more complex air current waveforms were characterized. 2. Based on a white analysis of receptor response properties, the median frequency of each receptor's frequency tuning curve was found to be strongly correlated with the length of its associated mechanosensory hair. The receptors connected to hairs > 900 microns encoded frequencies below approximately 150 Hz very accurately and the receptors connected to shorter hairs encoded progressively higher bands of frequencies. These results were interpreted within the constraints imposed by the biomechanics of the air current-to-cercus boundary. 3. The encoding accuracy was expressed in the information theoretic units of bits/second, which characterizes the information transmission rate of a receptor. The information rates of the neuronal spike trains ranged from 75 to 220 bits/s. The information transmission rate was not correlated with the length of the mechanosensory hair. The average amount of information transmitted per action potential was negatively correlated with receptor hair length and ranged between 0.6 and 3.1 bits/spike. Decoding of the receptor responses was restricted to linear transformations of the spike trains. 4. The stimulus/response latencies of the different receptors ranged between 5 and 11 ms, and the integration time of the receptors ranged between 8 and 30 ms. The latency of a receptor was only weakly correlated with the length of its associated hair, and a receptor's integration time was correlated with hair length. 5. The stimulus/response phase difference for receptor cells that innervated hairs longer than approximately 800 microns increased with frequency > 50 Hz. The phase responses for receptor cells connected to hairs < 800 microns did not vary for frequencies > 50 Hz.

scholarly journals A Scheme for Controlled Cyclic Asymmetric Remote State Preparation in Noisy Environment

2021 ◽  
Vol 11 (4) ◽  
pp. 1405
Author(s):  
Nan Zhao ◽  
Tingting Wu ◽  
Yan Yu ◽  
Changxing Pei
Keyword(s):  
Quantum Information ◽  
Information Transmission ◽  
Remote State Preparation ◽  
Quantum Computers ◽  
Noisy Environment ◽  
State Preparation ◽  
Channel Expression ◽  
Actual Environment ◽  
The Impact ◽  
Multi Mode

As research on quantum computers and quantum information transmission deepens, the multi-particle and multi-mode quantum information transmission has been attracting increasing attention. For scenarios where multi-parties transmit sequentially increasing qubits, we put forward a novel (N + 1)-party cyclic remote state preparation (RSP) protocol among an arbitrary number of players and a controller. Specifically, we employ a four-party scheme in the case of a cyclic asymmetric remote state preparation scheme and demonstrate the feasibility of the scheme on the IBM Quantum Experience platform. Furthermore, we present a general quantum channel expression under different circulation directions based on the n-party. In addition, considering the impact of the actual environment in the scheme, we discuss the feasibility of the scheme affected by different noises.

Factors influencing transmission of alfalfa mosaic virus through seed of annual medics (Medicago spp.) and the genetic control of seed transmission rate

1997 ◽  
Vol 48 (7) ◽  
pp. 989 ◽  
Author(s):  
W. Pathipanawat ◽  
R. A. C. Jones ◽  
K. Sivasithamparam
Keyword(s):  
Mosaic Virus ◽  
Genetic Control ◽  
Transmission Rate ◽  
Alfalfa Mosaic Virus ◽  
Seed Transmission ◽  
Virus Concentration ◽  
Rate Condition ◽  
Reciprocal Crosses ◽  
Transmission Rates ◽  
Annual Medics

Factors likely to influence rates of transmission of alfalfa mosaic virus (AMV) through seed to seedlings of annual medics (Medicago spp.) and genetic control of the magnitude of its seed transmission rate were investigated in plants from 17 early-flowering accessions of M. polymorpha and in progenies of crosses involving M. murex cv. Zodiac × accession 5320 as parents. Plants were graft-inoculated when 6 weeks old to ensure successful and uniform infection. To exclude variation in seed transmission rates due to virus isolate or temperature, only 1 AMV isolate was used and the plants were kept under uniform temperature conditions. In M. polymorpha, significant differences were found between accessions in the levels of AMV transmitted through seed to progeny seedlings, SA 8250 giving the highest mean level of seed transmission (52%) and SA 4188 the lowest (3%). Neither virus concentration nor symptom severity influenced the rates of seed transmission obtained. However, part of the variation in seed transmission rates found in these accessions was related to their flowering times, seed transmission rates increasing as the interval between inoculation and owering increased. In seed samples collected from individual graft-inoculated plants of M. murex from (i) the F2 generation from crosses and reciprocal crosses, and (ii) the backcross progenies, the rates of transmission of AMV through seed to seedlings ranged from 0 to 77% and showed a continuous pattern of variation. Also, there was evidence of transgressive segregation for the low seed transmission rate condition. This indicates that the low seed transmission rate condition for AMV in medics is quantitatively inherited and under polygenic control. In contrast, when the pods from F2 progeny plants from the crosses and reciprocal crosses were examined, the segregation ratios obtained revealed that the smooth pod character from parent accession 5320 was controlled by a single recessive gene, for which the name sp is proposed. The presence in a plant of gene sp, or of its spiny pod-determining allele from the other parent cv. Zodiac, was not correlated with low seed transmission rates of AMV. It is concluded that selection for low rates of seed transmission and a population breeding approach can be used to produce improved M. polymorpha and M. murex cultivars with good resistance to seed-borne AMV

scholarly journals Modeling the Novel Coronavirus (SARS-CoV-2) Outbreak in Sicily, Italy

2020 ◽  
Vol 17 (14) ◽  
pp. 4964 ◽  
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta ◽  
Sebastiano Battiato ◽  
Antonella Agodi
Keyword(s):  
Transmission Rate ◽  
Control Measures ◽  
Transmission Dynamics ◽  
The Novel ◽  
Epidemic Spread ◽  
Transmission Rates ◽  
Contact Precautions ◽  
Travel Restrictions ◽  
Novel Coronavirus ◽  
Reported Data

Italy was the first country in Europe which imposed control measures of travel restrictions, quarantine and contact precautions to tackle the epidemic spread of the novel coronavirus (SARS-CoV-2) in all its regions. While such efforts are still ongoing, uncertainties regarding SARS-CoV-2 transmissibility and ascertainment of cases make it difficult to evaluate the effectiveness of restrictions. Here, we employed a Susceptible-Exposed-Infectious-Recovered-Dead (SEIRD) model to assess SARS-CoV-2 transmission dynamics, working on the number of reported patients in intensive care unit (ICU) and deaths in Sicily (Italy), from 24 February to 13 April. Overall, we obtained a good fit between estimated and reported data, with a fraction of unreported SARS-CoV-2 cases (18.4%; 95%CI = 0–34.0%) before 10 March lockdown. Interestingly, we estimated that transmission rate in the community was reduced by 32% (95%CI = 23–42%) after the first set of restrictions, and by 80% (95%CI = 70–89%) after those adopted on 23 March. Thus, our estimates delineated the characteristics of SARS-CoV2 epidemic before restrictions taking into account unreported data. Moreover, our findings suggested that transmission rates were reduced after the adoption of control measures. However, we cannot evaluate whether part of this reduction might be attributable to other unmeasured factors, and hence further research and more accurate data are needed to understand the extent to which restrictions contributed to the epidemic control.

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