1
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Li C, Feng T, Tao Y, Zheng X, Wu J. Weak selection and stochastic evolutionary stability in a stochastic replicator dynamics. J Theor Biol 2023; 570:111524. [PMID: 37182722 DOI: 10.1016/j.jtbi.2023.111524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 04/30/2023] [Accepted: 05/08/2023] [Indexed: 05/16/2023]
Abstract
It is a very challenging problem whether natural selection is able to effectively resist the continuous disturbance of environmental noise such that the direction or outcome of evolution determined by the deterministic selection pressure will not be changed. By analyzing the impact of weak selection on the evolutionary stability of a stochastic replicator dynamics with n possible pure strategies, we found that the weak selection is able to enhance the evolutionary stability, that is, under weak selection, the stochastic evolutionary stability of the system is determined by the mean payoff matrix. This finding strongly implies that the weak selection should be regarded as an important mechanism to ensure evolutionary stability in stochastic environments.
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Affiliation(s)
- Cong Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xian, PR China
| | - Tianjiao Feng
- Key Laboratory of Animal Ecology and Conservation Biology, Center for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Yi Tao
- School of Ecology and Environment, Northwestern Polytechnical University, Xian, PR China; Key Laboratory of Animal Ecology and Conservation Biology, Center for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, PR China; Institute of Biomedical Research, Yunnan University, Kunming, PR China
| | - Xiudeng Zheng
- Key Laboratory of Animal Ecology and Conservation Biology, Center for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, PR China.
| | - Jiajia Wu
- College of Ecology, Lanzhou University, Lanzhou, PR China.
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2
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Kargovsky AV, Chichigina OA. Integrated random pulse process with positive and negative periodicity. Phys Rev E 2022; 106:024103. [PMID: 36109971 DOI: 10.1103/physreve.106.024103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
A study of nonstationary processes that are integrals of stationary random sequences of delta pulses is presented. An integrated renewal process can be represented as the sum of a deterministic linear function of time and a Wiener process of the corresponding intensity. This intensity is determined by the mean value and variance of the waiting times of the pulse process and is greater for super-Poisson processes than for sub-Poisson ones. Linear growth over time of all cumulants is proved. An integrated random process with fixed time intervals can be replaced by the sum of a deterministic linear function and a random process with bounded variance. The analytical results are in good agreement with the numerical ones.
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Affiliation(s)
- A V Kargovsky
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - O A Chichigina
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
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3
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Bakalis E, Gavriil V, Cefalas AC, Kollia Z, Zerbetto F, Sarantopoulou E. Viscoelasticity and Noise Properties Reveal the Formation of Biomemory in Cells. J Phys Chem B 2021; 125:10883-10892. [PMID: 34546052 PMCID: PMC8503882 DOI: 10.1021/acs.jpcb.1c01752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
![]()
Living cells are
neither perfectly elastic nor liquid and return
a viscoelastic response to external stimuli. Nanoindentation provides
force–distance curves, allowing the investigation of cell mechanical
properties, and yet, these curves can differ from point to point on
the cell surface, revealing its inhomogeneous character. In the present
work, we propose a mathematical method to estimate both viscoelastic
and noise properties of cells as these are depicted on the values
of the scaling exponents of relaxation function and power spectral
density, respectively. The method uses as input the time derivative
of the response force in a nanoindentation experiment. Generalized
moments method and/or rescaled range analysis is used to study the
resulting time series depending on their nonstationary or stationary
nature. We conducted experiments in living Ulocladium
chartarum spores. We found that spores in the approaching
phase present a viscoelastic behavior with the corresponding scaling
exponent in the range 0.25–0.52 and in the retracting phase
present a liquid-like behavior with exponents in the range 0.67–0.85.
This substantial difference of the scaling exponents in the two phases
suggests the formation of biomemory as a response of the spores to
the indenting AFM mechanical stimulus. The retracting phase may be
described as a process driven by bluish noises, while the approaching
one is driven by persistent noise.
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Affiliation(s)
- Evangelos Bakalis
- Dipartimento di Chimica "G. Ciamician", Universita di Bologna, V. F. Selmi 2, Bologna 40126, Italy
| | - Vassilios Gavriil
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece
| | - Alkiviadis-Constantinos Cefalas
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece
| | - Zoe Kollia
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece
| | - Francesco Zerbetto
- Dipartimento di Chimica "G. Ciamician", Universita di Bologna, V. F. Selmi 2, Bologna 40126, Italy
| | - Evangelia Sarantopoulou
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece
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4
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Shi RQ, Ren JN, Wang CH. Stability analysis and Hopf bifurcation of a fractional order mathematical model with time delay for nutrient-phytoplankton-zooplankton. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2020; 17:3836-3868. [PMID: 32987557 DOI: 10.3934/mbe.2020214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In recent years, some researchers paid their attention to the interaction between toxic phytoplankton and zooplankton. Their studies showed that the mechanism of food selection in zooplankton is still immature and when different algae of the same species (toxic and nontoxic) coexist, some zooplankton may not be able to distinguish between toxic and nontoxic algae, and even show a slight preference for toxic strains. Thus, in this article, a fractional order mathematical model with time delay is constructed to describe the interaction of nutrient-phytoplankton-toxic phytoplankton-zooplankton. The main purpose of this paper is to study the influence of fractional order and time delay on the ecosystem. The sufficient conditions for the existence and local stability of each equilibrium are obtained by using fractional order stability theory. By choosing time delay as the bifurcation parameter, we find that Hopf bifurcation occurs when the time delay passes through a sequence of critical values. After that, some numerical simulations are performed to support the analytic results. At last we make some conclusion and point out some possible future work.
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Affiliation(s)
- Rui Qing Shi
- School of Mathematics and Computer Science, Shanxi Normal University, Linfen, 041004, China
| | - Jia Ning Ren
- School of Mathematics and Computer Science, Shanxi Normal University, Linfen, 041004, China
| | - Cui Hong Wang
- School of Mathematics and Computer Science, Shanxi Normal University, Linfen, 041004, China
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5
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Mikhaylov A, Pimashkin A, Pigareva Y, Gerasimova S, Gryaznov E, Shchanikov S, Zuev A, Talanov M, Lavrov I, Demin V, Erokhin V, Lobov S, Mukhina I, Kazantsev V, Wu H, Spagnolo B. Neurohybrid Memristive CMOS-Integrated Systems for Biosensors and Neuroprosthetics. Front Neurosci 2020; 14:358. [PMID: 32410943 PMCID: PMC7199501 DOI: 10.3389/fnins.2020.00358] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/24/2020] [Indexed: 11/18/2022] Open
Abstract
Here we provide a perspective concept of neurohybrid memristive chip based on the combination of living neural networks cultivated in microfluidic/microelectrode system, metal-oxide memristive devices or arrays integrated with mixed-signal CMOS layer to control the analog memristive circuits, process the decoded information, and arrange a feedback stimulation of biological culture as parts of a bidirectional neurointerface. Our main focus is on the state-of-the-art approaches for cultivation and spatial ordering of the network of dissociated hippocampal neuron cells, fabrication of a large-scale cross-bar array of memristive devices tailored using device engineering, resistive state programming, or non-linear dynamics, as well as hardware implementation of spiking neural networks (SNNs) based on the arrays of memristive devices and integrated CMOS electronics. The concept represents an example of a brain-on-chip system belonging to a more general class of memristive neurohybrid systems for a new-generation robotics, artificial intelligence, and personalized medicine, discussed in the framework of the proposed roadmap for the next decade period.
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Affiliation(s)
- Alexey Mikhaylov
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Alexey Pimashkin
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Yana Pigareva
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | | | - Evgeny Gryaznov
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Sergey Shchanikov
- Department of Information Technologies, Vladimir State University, Murom, Russia
| | - Anton Zuev
- Department of Information Technologies, Vladimir State University, Murom, Russia
| | - Max Talanov
- Neuroscience Laboratory, Kazan Federal University, Kazan, Russia
| | - Igor Lavrov
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States
- Laboratory of Motor Neurorehabilitation, Kazan Federal University, Kazan, Russia
| | | | - Victor Erokhin
- Neuroscience Laboratory, Kazan Federal University, Kazan, Russia
- Kurchatov Institute, Moscow, Russia
- CNR-Institute of Materials for Electronics and Magnetism, Italian National Research Council, Parma, Italy
| | - Sergey Lobov
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
- Center for Technologies in Robotics and Mechatronics Components, Innopolis University, Innopolis, Russia
| | - Irina Mukhina
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
- Cell Technology Group, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Victor Kazantsev
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
- Center for Technologies in Robotics and Mechatronics Components, Innopolis University, Innopolis, Russia
| | - Huaqiang Wu
- Institute of Microelectronics, Tsinghua University, Beijing, China
| | - Bernardo Spagnolo
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
- Dipartimento di Fisica e Chimica-Emilio Segrè, Group of Interdisciplinary Theoretical Physics, Università di Palermo and CNISM, Unità di Palermo, Palermo, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Catania, Italy
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6
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Yu JR, Feng TJ, Zheng XD, Chen DH, Tao Y. Transitions in the cell-fate induction induced by colored noise associated with the inductive stimulus. J Theor Biol 2020; 484:110018. [PMID: 31550442 DOI: 10.1016/j.jtbi.2019.110018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 11/15/2022]
Abstract
The cell-fate induction based on the saddle-node bifurcation is undoubtedly a very important concept in developmental biology, which provides a possible mechanism to explain the intrinsic irreversibility in the developmental process. In this paper, the effect of a colored noise, which is associated with the inductive stimulus, on the saddle-node landscape of cell-fate induction is investigated, especially, the effect of the change of correlation time of colored noise on cell-fate induction. The main results show clearly that the change of correlation time of colored noise could induce the transitions of the system. This implies that the colored noise associated with inductive stimulus may have a profound effect on the saddle-node bifurcation landscape of cell-fate induction. This will also help us to understand more deeply the role of cell-fate induction in developmental biology.
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Affiliation(s)
- Jie-Ru Yu
- College of Resources and Environmental Sciences, Gansu Agricultural University, Lanzhou 730070, China; Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Tian-Jiao Feng
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; School of Systems Science, Beijing Normal University, Beijing 100875, China
| | - Xiu-Deng Zheng
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Da-Hua Chen
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Tao
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
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7
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Kargovsky AV, Chikishev AY, Chichigina OA. Effect of multiplicative noise on stationary stochastic process. Phys Rev E 2018; 97:032112. [PMID: 29776098 DOI: 10.1103/physreve.97.032112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Indexed: 11/07/2022]
Abstract
An open system that can be analyzed using the Langevin equation with multiplicative noise is considered. The stationary state of the system results from a balance of deterministic damping and random pumping simulated as noise with controlled periodicity. The dependence of statistical moments of the variable that characterizes the system on parameters of the problem is studied. A nontrivial decrease in the mean value of the main variable with an increase in noise stochasticity is revealed. Applications of the results in several physical, chemical, biological, and technical problems of natural and humanitarian sciences are discussed.
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Affiliation(s)
- A V Kargovsky
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - A Yu Chikishev
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - O A Chichigina
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
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8
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Zheng XD, Li C, Lessard S, Tao Y. Evolutionary stability concepts in a stochastic environment. Phys Rev E 2017; 96:032414. [PMID: 29347009 DOI: 10.1103/physreve.96.032414] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Indexed: 06/07/2023]
Abstract
Over the past 30 years, evolutionary game theory and the concept of an evolutionarily stable strategy have been not only extensively developed and successfully applied to explain the evolution of animal behaviors, but also widely used in economics and social sciences. Nonetheless, the stochastic dynamical properties of evolutionary games in randomly fluctuating environments are still unclear. In this study, we investigate conditions for stochastic local stability of fixation states and constant interior equilibria in a two-phenotype model with random payoffs following pairwise interactions. Based on this model, we develop the concepts of stochastic evolutionary stability (SES) and stochastic convergence stability (SCS). We show that the condition for a pure strategy to be SES and SCS is more stringent than in a constant environment, while the condition for a constant mixed strategy to be SES is less stringent than the condition to be SCS, which is less stringent than the condition in a constant environment.
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Affiliation(s)
- Xiu-Deng Zheng
- Key Laboratory of Animal Ecology and Conservation Biology, Centre for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Cong Li
- Department of Mathematics and Statistics, University of Montreal, Montreal QC H3C 3J7, Canada
| | - Sabin Lessard
- Department of Mathematics and Statistics, University of Montreal, Montreal QC H3C 3J7, Canada
| | - Yi Tao
- Key Laboratory of Animal Ecology and Conservation Biology, Centre for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100101, China
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9
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Ogura M, Wakaiki M, Rubin H, Preciado VM. Delayed bet-hedging resilience strategies under environmental fluctuations. Phys Rev E 2017; 95:052404. [PMID: 28618624 DOI: 10.1103/physreve.95.052404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Indexed: 06/07/2023]
Abstract
Many biological populations, such as bacterial colonies, have developed through evolution a protection mechanism, called bet hedging, to increase their probability of survival under stressful environmental fluctuation. In this context, the concept of preadaptation refers to a common type of bet-hedging protection strategy in which a relatively small number of individuals in a population stochastically switch their phenotypes to a dormant metabolic state in which they increase their probability of survival against potential environmental shocks. Hence, if an environmental shock took place at some point in time, preadapted organisms would be better adapted to survive and proliferate once the shock is over. In many biological populations, the mechanisms of preadaptation and proliferation present delays whose influence in the fitness of the population are not well understood. In this paper, we propose a rigorous mathematical framework to analyze the role of delays in both preadaptation and proliferation mechanisms in the survival of biological populations, with an emphasis on bacterial colonies. Our theoretical framework allows us to analytically quantify the average growth rate of a bet-hedging bacterial colony with stochastically delayed reactions with arbitrary precision. We verify the accuracy of the proposed method by numerical simulations and conclude that the growth rate of a bet-hedging population shows a nontrivial dependency on their preadaptation and proliferation delays. Contrary to the current belief, our results show that faster reactions do not, in general, increase the overall fitness of a biological population.
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Affiliation(s)
- Masaki Ogura
- Graduate School of Information Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Masashi Wakaiki
- Graduate School of System Informatics, Kobe University, Nada, Kobe, Hyogo 657-8501, Japan
| | - Harvey Rubin
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Victor M Preciado
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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10
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11
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Dubkov AA, Rudenko OV, Gurbatov SN. Probability characteristics of nonlinear dynamical systems driven by δ-pulse noise. Phys Rev E 2016; 93:062125. [PMID: 27415226 DOI: 10.1103/physreve.93.062125] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Indexed: 11/07/2022]
Abstract
For a nonlinear dynamical system described by the first-order differential equation with Poisson white noise having exponentially distributed amplitudes of δ pulses, some exact results for the stationary probability density function are derived from the Kolmogorov-Feller equation using the inverse differential operator. Specifically, we examine the "effect of normalization" of non-Gaussian noise by a linear system and the steady-state probability density function of particle velocity in the medium with Coulomb friction. Next, the general formulas for the probability distribution of the system perturbed by a non-Poisson δ-pulse train are derived using an analysis of system trajectories between stimuli. As an example, overdamped particle motion in the bistable quadratic-cubic potential under the action of the periodic δ-pulse train is analyzed in detail. The probability density function and the mean value of the particle position together with average characteristics of the first switching time from one stable state to another are found in the framework of the fast relaxation approximation.
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Affiliation(s)
- Alexander A Dubkov
- Radiophysics Department, Lobachevsky State University, Gagarin Ave. 23, 603950 Nizhni Novgorod, Russia
| | - Oleg V Rudenko
- Radiophysics Department, Lobachevsky State University, Gagarin Ave. 23, 603950 Nizhni Novgorod, Russia.,Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia.,Prokhorov General Physics Institute, Russian Academy of Sciences, ul. Vavilova 38, 119991 Moscow, Russia.,Schmidt Institute of the Earth, Russian Academy of Sciences, ul. B. Gruzinskaya 10, 123242 Moscow, Russia.,Blekinge Institute of Technology, SE-371 Karlskrona, Sweden
| | - Sergey N Gurbatov
- Radiophysics Department, Lobachevsky State University, Gagarin Ave. 23, 603950 Nizhni Novgorod, Russia
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12
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Kargovsky AV, Chichigina OA, Anashkina EI, Valenti D, Spagnolo B. Relaxation dynamics in the presence of pulse multiplicative noise sources with different correlation properties. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:042140. [PMID: 26565201 DOI: 10.1103/physreve.92.042140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Indexed: 06/05/2023]
Abstract
The relaxation dynamics of a system described by a Langevin equation with pulse multiplicative noise sources with different correlation properties is considered. The solution of the corresponding Fokker-Planck equation is derived for Gaussian white noise. Moreover, two pulse processes with regulated periodicity are considered as a noise source: the dead-time-distorted Poisson process and the process with fixed time intervals, which is characterized by an infinite correlation time. We find that the steady state of the system is dependent on the correlation properties of the pulse noise. An increase of the noise correlation causes the decrease of the mean value of the solution at the steady state. The analytical results are in good agreement with the numerical ones.
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Affiliation(s)
- A V Kargovsky
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory, 119992 Moscow, Russia
| | - O A Chichigina
- Faculty of Physics and International Laser Center, Lomonosov Moscow State University, Leninskie Gory, 119992 Moscow, Russia
| | - E I Anashkina
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 119992 Moscow, Russia and Dipartimento di Fisica e Chimica, Group of Interdisciplinary Theoretical Physics, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo, Italy
| | - D Valenti
- Dipartimento di Fisica e Chimica, Group of Interdisciplinary Theoretical Physics, Università di Palermo and CNISM, Unità di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Italy
| | - B Spagnolo
- Dipartimento di Fisica e Chimica, Group of Interdisciplinary Theoretical Physics, Università di Palermo and CNISM, Unità di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Italy
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13
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Valenti D, Denaro G, Spagnolo B, Conversano F, Brunet C. How diffusivity, thermocline and incident light intensity modulate the dynamics of deep chlorophyll maximum in Tyrrhenian Sea. PLoS One 2015; 10:e0115468. [PMID: 25629963 PMCID: PMC4309620 DOI: 10.1371/journal.pone.0115468] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 11/23/2014] [Indexed: 11/22/2022] Open
Abstract
During the last few years theoretical works have shed new light and proposed new hypotheses on the mechanisms which regulate the spatio-temporal behaviour of phytoplankton communities in marine pelagic ecosystems. Despite this, relevant physical and biological issues, such as effects of the time-dependent mixing in the upper layer, competition between groups, and dynamics of non-stationary deep chlorophyll maxima, are still open questions. In this work, we analyze the spatio-temporal behaviour of five phytoplankton populations in a real marine ecosystem by using a one-dimensional reaction-diffusion-taxis model. The study is performed, taking into account the seasonal variations of environmental variables, such as light intensity, thickness of upper mixed layer and profiles of vertical turbulent diffusivity, obtained starting from experimental findings. Theoretical distributions of phytoplankton cell concentration was converted in chlorophyll concentration, and compared with the experimental profiles measured in a site of the Tyrrhenian Sea at four different times (seasons) of the year, during four different oceanographic cruises. As a result we find a good agreement between theoretical and experimental distributions of chlorophyll concentration. In particular, theoretical results reveal that the seasonal changes of environmental variables play a key role in the phytoplankton distribution and determine the properties of the deep chlorophyll maximum. This study could be extended to other marine ecosystems to predict future changes in the phytoplankton biomass due to global warming, in view of devising strategies to prevent the decline of the primary production and the consequent decrease of fish species.
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Affiliation(s)
- Davide Valenti
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
- * E-mail:
| | - Giovanni Denaro
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Bernardo Spagnolo
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Theoretical Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
- Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Catania, Italy
- Radiophysics Department, Lobachevsky State University, Nizhniy Novgorod, Russia
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14
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Wang Y, Cao J, Sun GQ, Li J. Effect of time delay on pattern dynamics in a spatial epidemic model. PHYSICA A 2014; 412:137-148. [PMID: 32308253 PMCID: PMC7156238 DOI: 10.1016/j.physa.2014.06.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/10/2014] [Indexed: 06/11/2023]
Abstract
Time delay, accounting for constant incubation period or sojourn times in an infective state, widely exists in most biological systems like epidemiological models. However, the effect of time delay on spatial epidemic models is not well understood. In this paper, spatial pattern of an epidemic model with both nonlinear incidence rate and time delay is investigated. In particular, we mainly focus on the effect of time delay on the formation of spatial pattern. Through mathematical analysis, we gain the conditions for Hopf bifurcation and Turing bifurcation, and find exact Turing space in parameter space. Furthermore, numerical results show that time delay has a significant effect on pattern formation. The simulation results may enrich the finding of patterns and may well capture some key features in the epidemic models.
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Affiliation(s)
- Yi Wang
- Department of Mathematics, Southeast University, Nanjing 210096, People's Republic of China
| | - Jinde Cao
- Department of Mathematics, Southeast University, Nanjing 210096, People's Republic of China
- Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Gui-Quan Sun
- Complex Systems Research Center, Shanxi University, Taiyuan, Shanxi 030006, People's Republic of China
- Department of Mathematics, North University of China, Taiyuan, Shanxi 030051, People's Republic of China
| | - Jing Li
- Department of Mathematics, North University of China, Taiyuan, Shanxi 030051, People's Republic of China
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Denaro G, Valenti D, Spagnolo B, Basilone G, Mazzola S, Zgozi SW, Aronica S, Bonanno A. Dynamics of two picophytoplankton groups in mediterranean sea: analysis of the deep chlorophyll maximum by a stochastic advection-reaction-diffusion model. PLoS One 2013; 8:e66765. [PMID: 23826130 PMCID: PMC3691268 DOI: 10.1371/journal.pone.0066765] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/13/2013] [Indexed: 11/25/2022] Open
Abstract
A stochastic advection-reaction-diffusion model with terms of multiplicative white Gaussian noise, valid for weakly mixed waters, is studied to obtain the vertical stationary spatial distributions of two groups of picophytoplankton, i.e., picoeukaryotes and Prochlorococcus, which account about for 60% of total chlorophyll on average in Mediterranean Sea. By numerically solving the equations of the model, we analyze the one-dimensional spatio-temporal dynamics of the total picophytoplankton biomass and nutrient concentration along the water column at different depths. In particular, we integrate the equations over a time interval long enough, obtaining the steady spatial distributions for the cell concentrations of the two picophytoplankton groups. The results are converted into chlorophyll a and divinil chlorophyll a concentrations and compared with experimental data collected in two different sites of the Sicily Channel (southern Mediterranean Sea). The comparison shows that real distributions are well reproduced by theoretical profiles. Specifically, position, shape and magnitude of the theoretical deep chlorophyll maximum exhibit a good agreement with the experimental values.
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Affiliation(s)
- Giovanni Denaro
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Davide Valenti
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Bernardo Spagnolo
- Dipartimento di Fisica e Chimica, Università di Palermo, Group of Interdisciplinary Physics and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Unità di Palermo, Palermo, Italy
| | - Gualtiero Basilone
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | - Salvatore Mazzola
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | | | - Salvatore Aronica
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
| | - Angelo Bonanno
- Istituto per l’Ambiente Marino Costiero, Centro Nazionale delle Ricerche, Unità Operativa di Supporto di Capo Granitola, Campobello di Mazara, Trapani, Italy
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Kargovsky AV, Anashkina EI, Chichigina OA, Krasnova AK. Velocity distribution for quasistable acceleration in the presence of multiplicative noise. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:042133. [PMID: 23679397 DOI: 10.1103/physreve.87.042133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 04/16/2013] [Indexed: 06/02/2023]
Abstract
Processes that are far both from equilibrium and from phase transition are studied. It is shown that a process with mean velocity that exhibits power-law growth in time can be analyzed using the Langevin equation with multiplicative noise. The solution to the corresponding Fokker-Planck equation is derived. Results of the numerical solution of the Langevin equation and simulation of the motion of particles in a billiard system with a time-dependent boundary are presented.
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Affiliation(s)
- A V Kargovsky
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 119992 Moscow, Russia.
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