A delayed n-species nonautonomous Lotka-Volterra type competitive system without dominating instantaneous negative feedback is investigated. By means of a suitable Lyapunov functional, sufficient conditions are derive...A delayed n-species nonautonomous Lotka-Volterra type competitive system without dominating instantaneous negative feedback is investigated. By means of a suitable Lyapunov functional, sufficient conditions are derived for the global asymptotic stability of the positive solutions of the system. As a corollary, it is shown that the global asymptotic stability of the positive solution is maintained provided that the delayed negative feedbacks dominate other interspecific interaction effects with delays and the delays are sufficiently small.展开更多
A strongly coupled elliptic system under the homogeneous Dirichlet boundary condition denoting the steady-state system of the Lotka-Volterra two-species competitive system with cross-diffusion effects is considered. B...A strongly coupled elliptic system under the homogeneous Dirichlet boundary condition denoting the steady-state system of the Lotka-Volterra two-species competitive system with cross-diffusion effects is considered. By using the implicit function theorem and the Lyapunov- Schmidt reduction method, the existence of the positive solutions bifurcating from the trivial solution is obtained. Furthermore, the stability of the bifurcating positive solutions is also investigated by analyzing the associated characteristic equation.展开更多
This paper investigates the persistence and existence of almost periodic solutions for a discrete competitive system with feedback controls based on the comparison theorem of the difference equation and constructing a...This paper investigates the persistence and existence of almost periodic solutions for a discrete competitive system with feedback controls based on the comparison theorem of the difference equation and constructing appropriate Lyapunov function, and several sufficient conditions for the existence of positive almost periodic solutions for the model are obtained.Finally, a numerical example is given to illustrate effectiveness of our main results.展开更多
A class of non-autonomous two species Lotka-Volterra competitive system with pure discrete time delays is discussed. Some sufficient conditions on the boundedness, permanence, periodic solution and global attractivity...A class of non-autonomous two species Lotka-Volterra competitive system with pure discrete time delays is discussed. Some sufficient conditions on the boundedness, permanence, periodic solution and global attractivity of the system are established by means of the comparison method and Liapunov functional.展开更多
In this paper, we consider a stochastic non-autonomous Schoener competitive system. Firstly, we prove the existence of positive periodic solution when the coefficients of Schoener competitive system satisfied certain ...In this paper, we consider a stochastic non-autonomous Schoener competitive system. Firstly, we prove the existence of positive periodic solution when the coefficients of Schoener competitive system satisfied certain conditions. Then the global attractiveness of positive periodic solution is also proved by constructing appropriate Lyapunov function. In addition, we show that the stronger noises will lead to the extinction of competitive systems.展开更多
Gyllenberg and Yan(Discrete Contin Dyn Syst Ser B 11(2):347–352,2009)presented a system in Zeeman’s class 30 of 3-dimensional Lotka-Volterra(3D LV)competitive systems to admit at least two limit cycles,one of which ...Gyllenberg and Yan(Discrete Contin Dyn Syst Ser B 11(2):347–352,2009)presented a system in Zeeman’s class 30 of 3-dimensional Lotka-Volterra(3D LV)competitive systems to admit at least two limit cycles,one of which is generated by the Hopf bifurcation and the other is obtained by the Poincaré-Bendixson theorem.Yu et al.(J Math Anal Appl 436:521–555,2016,Sect.3.4)recalculated the first Liapunov coefficient of Gyllenberg and Yan’s system to be positive,rather than negative as in Gyllenberg and Yan(2009),and pointed out that the Poincaré-Bendixson theorem is not applicable for that system.Jiang et al.(J Differ Equ 284:183–218,2021,p.213)proposed an open question:“whether Zeeman’s class 30 can be rigorously proved to admit at least two limit cycles by the Hopf theorem and the Poincaré-Bendixson theorem?”This paper provides four systems in Zeeman’s class 30 to admit at least two limit cycles by the Hopf theorem and the Poincaré-Bendixson theorem and gives an answer to the above question.展开更多
Quantifying and mapping how ecosystem services impact agricultural competitiveness is crucial for attaining the Sustainable Development Goals of United Nations.However,few study quantified agricultural competitiveness...Quantifying and mapping how ecosystem services impact agricultural competitiveness is crucial for attaining the Sustainable Development Goals of United Nations.However,few study quantified agricultural competitiveness and mapped the effects of ecosystem services on agricultural competitiveness using multiple models.In this study,multi-source data from 2000 to 2020 were utilized to establish the indicator system of agricultural competitiveness;five ecosystem services were quantified using computation models;Geographic Information System(GIS)spatial analysis was used to explore the spatial patterns of agricultural competitiveness and ecosystem services;geographic detector models were applied to investigate the effects and driving mechanisms of ecosystem services on agricultural competitiveness.Shandong Province of China was selected as the case study area.The results demonstrated that:1)there was a significant increase in agricultural competitiveness during the study period,with high levels observed mainly in the east region of the study area.2)The spatial distribution patterns of ecosystem services and agricultural competitiveness primarily exhibited High-High and Low-Low Cluster types.3)Habitat quality emerged as the main driving factor of agricultural competitiveness in 2000 and 2020,while water yield played a substantial role in 2010.4)The coupling of two ecosystem services exerted a greater effect on agricultural competitiveness compared to individual ecosystem service.The innovations of this study are constructing an indicator system to quantify agricultural competitiveness,and exploring the effects of ecosystem services on agricultural competitiveness.This study proposed an indicator system to quantify agricultural competitiveness,which can be applied in other regions,and explored the effects of ecosystem services on agricultural competitiveness.The findings of this study can serve as valuable insights for policymakers to formulate tailored agricultural development policies that take into account the synergistic effects of ecosystem services on agricultural competitiveness.展开更多
The distribution and competitive behaviors of phosphotungstic acid and ferric chloride in the TBP-HCl-H_(2)O system were investigated by controlling the extractant concentration and the solution environment.The result...The distribution and competitive behaviors of phosphotungstic acid and ferric chloride in the TBP-HCl-H_(2)O system were investigated by controlling the extractant concentration and the solution environment.The results revealed that phosphotungstic acid exhibited a strong affinity for TBP with decreasing TBP concentration.Higher acidity significantly improved the W extraction efficiency with TBP,and the lower Cl^(-)concentration reduced the extraction efficiency of Fe.As the organic phase approached saturation point,phosphotungstic acid competitively displaced Fe to combine with TBP.The hydrogen bond structure(P=O·HO-P-W-O)between phosphotungstic acid and TBP was characterized by FT-IR,and the salting-out effect induced by FeCl_(3) was elucidated.In summary,high acidity is beneficial for exhaustive extraction of W,and an effective W/Fe separation can be achieved by reducing the concentrations of TBP and Cl^(-).展开更多
This study observes the process of strategy building and capability accumulation of companies in the currently booming Chinese electric vehicles(EV)1 market from the perspective of business ecosystems.While examining ...This study observes the process of strategy building and capability accumulation of companies in the currently booming Chinese electric vehicles(EV)1 market from the perspective of business ecosystems.While examining the internal and external factors of the formation about the Chinese EV industry business ecosystem,such as industrial structure transformation,technology transfer,government policies,and corporate competition,with the platform theory,I analyze the growth strategies and competitiveness of Chinese companies,particularly BYD Co.,Ltd.(BYD),which has risen to the top of the world in EV completed vehicles,and Contemporary Amperex Technology Co.,Ltd.(CATL),which has risen to the top of the world in electric vehicle batteries(EVB)2.BYD and CATL have gained competitive advantages by utilizing the distinctive management resources,which have accumulated over the years to build platforms for EVBs and EVs in response to changes in the external environment,and have actively developed their platform strategies.展开更多
The differences in the competitive reactions of hydrogarnet and quicklime when reacting with titaniumcontaining and silicon-containing minerals during the Bayer digestion process were investigated.Thermodynamic analys...The differences in the competitive reactions of hydrogarnet and quicklime when reacting with titaniumcontaining and silicon-containing minerals during the Bayer digestion process were investigated.Thermodynamic analysis,artificial mineral experiments,and an evaluation of the digestion effect of natural diasporic bauxite were conducted.The results indicate that hydrogarnet shows a preferential reaction with anatase,and this preference becomes more pronounced as the silicon saturation coefficient increases.In contrast,quicklime participates in non-selective reactions with both anatase and desilication products(DSP).The preference of hydrogarnet for anatase significantly enhances the utilization efficiency of CaO in the high-temperature Bayer digestion process.展开更多
Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The...Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The long noncoding RNA growth arrest-specific 5(GAS5) is a member of the 5′-terminal oligopyrimidine gene family that may be involved in neurological disorders, but its role in Alzheimer's disease remains unclear. This study aimed to investigate the function of GAS5 and construct a GAS5-associated competitive endogenous RNA network comprising potential targets. RNA sequencing results showed that GAS5 was upregulated in five familial Alzheimer's disease(5×FAD) mice, APPswe/PSEN1dE9(APP/PS1) mice, Alzheimer's disease-related APPswe cells, and serum from patients with Alzheimer's disease. Functional experiments with targeted overexpression and silencing demonstrated that GAS5 played a role in cognitive dysfunction and multiple Alzheimer's disease-associated pathologies, including tau hyperphosphorylation, amyloid-beta accumulation, and neuronal apoptosis. Mechanistic studies indicated that GAS5 acted as an endogenous sponge by competing for microRNA-23b-3p(miR-23b-3p) binding to regulate its targets glycogen synthase kinase 3beta(GSK-3β) and phosphatase and tensin homologue deleted on chromosome 10(PTEN) expression in an Argonaute 2-induced RNA silencing complex(RISC)-dependent manner. GAS5 inhibited miR-23b-3p-mediated GSK-3β and PTEN cascades with a feedforward PTEN/protein kinase B(Akt)/GSK-3β linkage. Furthermore, recovery of GAS5/miR-23b-3p/GSK-3β/PTEN pathways relieved Alzheimer's disease-like symptoms in vivo, indicated by the amelioration of spatial cognition, neuronal degeneration, amyloid-beta load, and tau phosphorylation. Together, these findings suggest that GAS5 promotes Alzheimer's disease pathogenesis. This study establishes the functional convergence of the GAS5/miR-23b-3p/GSK-3β/PTEN pathway on multiple pathologies, suggesting a candidate therapeutic target in Alzheimer's disease.展开更多
A generalized competitive system with stochastic perturbations is proposed in this paper,in which the stochastic disturbances are described by the famous Ornstein–Uhlenbeck process.By theories of stochastic different...A generalized competitive system with stochastic perturbations is proposed in this paper,in which the stochastic disturbances are described by the famous Ornstein–Uhlenbeck process.By theories of stochastic differential equations,such as comparison theorem,Ito’s integration formula,Chebyshev’s inequality,martingale’s properties,etc.,the existence and the uniqueness of global positive solution of the system are obtained.Then sufficient conditions for the extinction of the species almost surely,persistence in the mean and the stochastic permanence for the system are derived,respectively.Finally,by a series of numerical examples,the feasibility and correctness of the theoretical analysis results are verified intuitively.Moreover,the effects of the intensity of the stochastic perturbations and the speed of the reverse in the Ornstein–Uhlenbeck process to the dynamical behavior of the system are also discussed.展开更多
The asymptotic behavior of an almost periodic competitive system is investigated. By using differential inequality, the module containment theorem and the Lyapunov function, a good understanding of the existence and g...The asymptotic behavior of an almost periodic competitive system is investigated. By using differential inequality, the module containment theorem and the Lyapunov function, a good understanding of the existence and global asymptotic stability of posi- tive almost periodic solutions is obtained. Finally, an example and numerical simulations are performed for justifying the theoretical results.展开更多
In the real world, the population systems are often subject to white noises and a system with such stochastic perturbations tends to be suitably modeled by stochastic differential equations. This paper is concerned wi...In the real world, the population systems are often subject to white noises and a system with such stochastic perturbations tends to be suitably modeled by stochastic differential equations. This paper is concerned with the dynamic behaviors of a delay stochastic competitive system. We first obtain the global existence of a unique positive solution of system. Later, we show that the solution of system will be stochastically ultimate boundedness. However, large noises may make the system extinct exponentially with probability one. Also, sufficient conditions for the global attractivity of system are established. FinMly, illustrated examples are given to show the effectiveness of the proposed criteria.展开更多
A class of nonlinear two-species competitive singularly perturbed initial-boundary-value problems for reaction-diffusion systems are studied. Under suitable assumptions, by using the stretched variable, the formal asy...A class of nonlinear two-species competitive singularly perturbed initial-boundary-value problems for reaction-diffusion systems are studied. Under suitable assumptions, by using the stretched variable, the formal asymptotic expansion for the problems is constructed. The uniform validity of the solution for initial-boundary-value problems is obtained by using the theory of differential inequalities.展开更多
In this paper, we consider almost periodic discrete two-species competitive sys-tems. By using Lyapunov functional, the existence conditions and uniqueness of almost periodic solutions for the this type of systems are...In this paper, we consider almost periodic discrete two-species competitive sys-tems. By using Lyapunov functional, the existence conditions and uniqueness of almost periodic solutions for the this type of systems are obtained.展开更多
A two species Lotka-Volterra competitive system with infinite delays and feedback controls is studied in this paper.By constructing a suitable Lyapunov functional,we show that if the Lotka-Volterra competitive system ...A two species Lotka-Volterra competitive system with infinite delays and feedback controls is studied in this paper.By constructing a suitable Lyapunov functional,we show that if the Lotka-Volterra competitive system is bistable(in the absence of feedback controls),then by choosing some suitable values of feedback control variables,one of the species is driven to extinction while the other one becomes globally stable.Examples together with their numerical simulations are presented to verify the feasibility of our results.Our results not only improve but also complement those of Z.Li,M.A.Han and F.D.Chen[Influence of feedback controls on an autonomous Lotka-Volterra competitive system with infinite delays,Nonlinear Anal.:Real World Appl.,14(2013),402-413].展开更多
In this paper, we consider a discrete competitive system with BeddingtonDe Angelis functional response and the effect of toxic substances. By constructing some suitable Lyapunov type extinction functions, sufficient c...In this paper, we consider a discrete competitive system with BeddingtonDe Angelis functional response and the effect of toxic substances. By constructing some suitable Lyapunov type extinction functions, sufficient conditions which guarantee the extinction of a species and global attractivity of the other one are obtained. Our results not only supplement and improve but also generalize some existing ones. Numerical simulations show the feasibility of our results.展开更多
In this paper, the impulsive exploitation of two species periodic competitive system is considered. First, we show that this type of system with impulsive harvesting has a unique positive periodicsolution, which is gl...In this paper, the impulsive exploitation of two species periodic competitive system is considered. First, we show that this type of system with impulsive harvesting has a unique positive periodicsolution, which is globally asymptotically stable. Further, by choosing the maximum total revenues as the management objective, we investigate the optimal harvesting policies for periodic competitive system with impulsive harvesting. Finally, we obtain the optimal time to harvest and optimal population level.展开更多
A competitive system on the n-rectangle： {x ∈ Rn： 0 ≤ xi ≤ li, i = 1,... ,n} was con- sidered, each species of which, in isolation, admits logistic growth with the hyperbolic structure saturation. It has an （n ...A competitive system on the n-rectangle： {x ∈ Rn： 0 ≤ xi ≤ li, i = 1,... ,n} was con- sidered, each species of which, in isolation, admits logistic growth with the hyperbolic structure saturation. It has an （n - 1）-dimensional invariant surface called carrying simplex E as a globe attractor, hence the long term dynamics of the system is com- pletely determined by the dynamics on E. For the three-dimensional system, the whole dynamical behavior was presented. It has a unique positive equilibrium point and any limit set is either an equilibrium point or a limit cycle. The system is permanent and it is proved that the number of periodic orbits is finite and non-periodic oscillation the May Leonard phenomenon does not exist. A criterion for the positive equilibrium to be globally asymptotically stable is provided. Whether there exist limit cycles or not remains open.展开更多
文摘A delayed n-species nonautonomous Lotka-Volterra type competitive system without dominating instantaneous negative feedback is investigated. By means of a suitable Lyapunov functional, sufficient conditions are derived for the global asymptotic stability of the positive solutions of the system. As a corollary, it is shown that the global asymptotic stability of the positive solution is maintained provided that the delayed negative feedbacks dominate other interspecific interaction effects with delays and the delays are sufficiently small.
基金Supported by the National Natural Science Foundation of China (10961017)"Qinglan" Talent Programof Lanzhou Jiaotong University (QL-05-20A)
文摘A strongly coupled elliptic system under the homogeneous Dirichlet boundary condition denoting the steady-state system of the Lotka-Volterra two-species competitive system with cross-diffusion effects is considered. By using the implicit function theorem and the Lyapunov- Schmidt reduction method, the existence of the positive solutions bifurcating from the trivial solution is obtained. Furthermore, the stability of the bifurcating positive solutions is also investigated by analyzing the associated characteristic equation.
基金Supported by the National Natural Science Foundation of China(Grant No.11561070)the Natural Scientific Research Fund Project of Yunnan Province(Grant No.2014FD049)
文摘This paper investigates the persistence and existence of almost periodic solutions for a discrete competitive system with feedback controls based on the comparison theorem of the difference equation and constructing appropriate Lyapunov function, and several sufficient conditions for the existence of positive almost periodic solutions for the model are obtained.Finally, a numerical example is given to illustrate effectiveness of our main results.
文摘A class of non-autonomous two species Lotka-Volterra competitive system with pure discrete time delays is discussed. Some sufficient conditions on the boundedness, permanence, periodic solution and global attractivity of the system are established by means of the comparison method and Liapunov functional.
文摘In this paper, we consider a stochastic non-autonomous Schoener competitive system. Firstly, we prove the existence of positive periodic solution when the coefficients of Schoener competitive system satisfied certain conditions. Then the global attractiveness of positive periodic solution is also proved by constructing appropriate Lyapunov function. In addition, we show that the stronger noises will lead to the extinction of competitive systems.
基金the National Natural Science Foundation of China(NSFC)under Grant No.12171321.
文摘Gyllenberg and Yan(Discrete Contin Dyn Syst Ser B 11(2):347–352,2009)presented a system in Zeeman’s class 30 of 3-dimensional Lotka-Volterra(3D LV)competitive systems to admit at least two limit cycles,one of which is generated by the Hopf bifurcation and the other is obtained by the Poincaré-Bendixson theorem.Yu et al.(J Math Anal Appl 436:521–555,2016,Sect.3.4)recalculated the first Liapunov coefficient of Gyllenberg and Yan’s system to be positive,rather than negative as in Gyllenberg and Yan(2009),and pointed out that the Poincaré-Bendixson theorem is not applicable for that system.Jiang et al.(J Differ Equ 284:183–218,2021,p.213)proposed an open question:“whether Zeeman’s class 30 can be rigorously proved to admit at least two limit cycles by the Hopf theorem and the Poincaré-Bendixson theorem?”This paper provides four systems in Zeeman’s class 30 to admit at least two limit cycles by the Hopf theorem and the Poincaré-Bendixson theorem and gives an answer to the above question.
基金Under the auspices of the National Key Research and Development Program of China(No.2022YFC3204404)。
文摘Quantifying and mapping how ecosystem services impact agricultural competitiveness is crucial for attaining the Sustainable Development Goals of United Nations.However,few study quantified agricultural competitiveness and mapped the effects of ecosystem services on agricultural competitiveness using multiple models.In this study,multi-source data from 2000 to 2020 were utilized to establish the indicator system of agricultural competitiveness;five ecosystem services were quantified using computation models;Geographic Information System(GIS)spatial analysis was used to explore the spatial patterns of agricultural competitiveness and ecosystem services;geographic detector models were applied to investigate the effects and driving mechanisms of ecosystem services on agricultural competitiveness.Shandong Province of China was selected as the case study area.The results demonstrated that:1)there was a significant increase in agricultural competitiveness during the study period,with high levels observed mainly in the east region of the study area.2)The spatial distribution patterns of ecosystem services and agricultural competitiveness primarily exhibited High-High and Low-Low Cluster types.3)Habitat quality emerged as the main driving factor of agricultural competitiveness in 2000 and 2020,while water yield played a substantial role in 2010.4)The coupling of two ecosystem services exerted a greater effect on agricultural competitiveness compared to individual ecosystem service.The innovations of this study are constructing an indicator system to quantify agricultural competitiveness,and exploring the effects of ecosystem services on agricultural competitiveness.This study proposed an indicator system to quantify agricultural competitiveness,which can be applied in other regions,and explored the effects of ecosystem services on agricultural competitiveness.The findings of this study can serve as valuable insights for policymakers to formulate tailored agricultural development policies that take into account the synergistic effects of ecosystem services on agricultural competitiveness.
基金supported by the National key R&D Program of China(No.2022YFC2905105)the National Natural Science Foundation of China(No.72088101)。
文摘The distribution and competitive behaviors of phosphotungstic acid and ferric chloride in the TBP-HCl-H_(2)O system were investigated by controlling the extractant concentration and the solution environment.The results revealed that phosphotungstic acid exhibited a strong affinity for TBP with decreasing TBP concentration.Higher acidity significantly improved the W extraction efficiency with TBP,and the lower Cl^(-)concentration reduced the extraction efficiency of Fe.As the organic phase approached saturation point,phosphotungstic acid competitively displaced Fe to combine with TBP.The hydrogen bond structure(P=O·HO-P-W-O)between phosphotungstic acid and TBP was characterized by FT-IR,and the salting-out effect induced by FeCl_(3) was elucidated.In summary,high acidity is beneficial for exhaustive extraction of W,and an effective W/Fe separation can be achieved by reducing the concentrations of TBP and Cl^(-).
文摘This study observes the process of strategy building and capability accumulation of companies in the currently booming Chinese electric vehicles(EV)1 market from the perspective of business ecosystems.While examining the internal and external factors of the formation about the Chinese EV industry business ecosystem,such as industrial structure transformation,technology transfer,government policies,and corporate competition,with the platform theory,I analyze the growth strategies and competitiveness of Chinese companies,particularly BYD Co.,Ltd.(BYD),which has risen to the top of the world in EV completed vehicles,and Contemporary Amperex Technology Co.,Ltd.(CATL),which has risen to the top of the world in electric vehicle batteries(EVB)2.BYD and CATL have gained competitive advantages by utilizing the distinctive management resources,which have accumulated over the years to build platforms for EVBs and EVs in response to changes in the external environment,and have actively developed their platform strategies.
基金the financial support from the Natural Science Foundation of Hunan Province,China(No.2022JJ40616)。
文摘The differences in the competitive reactions of hydrogarnet and quicklime when reacting with titaniumcontaining and silicon-containing minerals during the Bayer digestion process were investigated.Thermodynamic analysis,artificial mineral experiments,and an evaluation of the digestion effect of natural diasporic bauxite were conducted.The results indicate that hydrogarnet shows a preferential reaction with anatase,and this preference becomes more pronounced as the silicon saturation coefficient increases.In contrast,quicklime participates in non-selective reactions with both anatase and desilication products(DSP).The preference of hydrogarnet for anatase significantly enhances the utilization efficiency of CaO in the high-temperature Bayer digestion process.
基金supported by the National Natural Science Foundation of China,Nos. 82173806 and U1803281Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Science,Nos. 2021-I2M-1-030 and 2022-I2M-2-002Non-Profit Central Research Institute Fund of Chinese Academy of Medical Sciences,No. 2022-JKCS-08 (all to RL)。
文摘Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The long noncoding RNA growth arrest-specific 5(GAS5) is a member of the 5′-terminal oligopyrimidine gene family that may be involved in neurological disorders, but its role in Alzheimer's disease remains unclear. This study aimed to investigate the function of GAS5 and construct a GAS5-associated competitive endogenous RNA network comprising potential targets. RNA sequencing results showed that GAS5 was upregulated in five familial Alzheimer's disease(5×FAD) mice, APPswe/PSEN1dE9(APP/PS1) mice, Alzheimer's disease-related APPswe cells, and serum from patients with Alzheimer's disease. Functional experiments with targeted overexpression and silencing demonstrated that GAS5 played a role in cognitive dysfunction and multiple Alzheimer's disease-associated pathologies, including tau hyperphosphorylation, amyloid-beta accumulation, and neuronal apoptosis. Mechanistic studies indicated that GAS5 acted as an endogenous sponge by competing for microRNA-23b-3p(miR-23b-3p) binding to regulate its targets glycogen synthase kinase 3beta(GSK-3β) and phosphatase and tensin homologue deleted on chromosome 10(PTEN) expression in an Argonaute 2-induced RNA silencing complex(RISC)-dependent manner. GAS5 inhibited miR-23b-3p-mediated GSK-3β and PTEN cascades with a feedforward PTEN/protein kinase B(Akt)/GSK-3β linkage. Furthermore, recovery of GAS5/miR-23b-3p/GSK-3β/PTEN pathways relieved Alzheimer's disease-like symptoms in vivo, indicated by the amelioration of spatial cognition, neuronal degeneration, amyloid-beta load, and tau phosphorylation. Together, these findings suggest that GAS5 promotes Alzheimer's disease pathogenesis. This study establishes the functional convergence of the GAS5/miR-23b-3p/GSK-3β/PTEN pathway on multiple pathologies, suggesting a candidate therapeutic target in Alzheimer's disease.
基金This work is supported by the Sichuan Science and Technology Program under Grant 2017JY0336 and Hunan Science and Technology Program under Grant 2019JJ50399National College Students,Innovation and Entrepreneurship Training Program under Grant S202010619021Longshan Talent Research Fund of Southwest University of Science and Technology under Grants 17LZX670 and 18LZX622.
文摘A generalized competitive system with stochastic perturbations is proposed in this paper,in which the stochastic disturbances are described by the famous Ornstein–Uhlenbeck process.By theories of stochastic differential equations,such as comparison theorem,Ito’s integration formula,Chebyshev’s inequality,martingale’s properties,etc.,the existence and the uniqueness of global positive solution of the system are obtained.Then sufficient conditions for the extinction of the species almost surely,persistence in the mean and the stochastic permanence for the system are derived,respectively.Finally,by a series of numerical examples,the feasibility and correctness of the theoretical analysis results are verified intuitively.Moreover,the effects of the intensity of the stochastic perturbations and the speed of the reverse in the Ornstein–Uhlenbeck process to the dynamical behavior of the system are also discussed.
文摘The asymptotic behavior of an almost periodic competitive system is investigated. By using differential inequality, the module containment theorem and the Lyapunov function, a good understanding of the existence and global asymptotic stability of posi- tive almost periodic solutions is obtained. Finally, an example and numerical simulations are performed for justifying the theoretical results.
基金Acknowledgments The authors thank the referees for their reports and many valuable comments and suggestions that greatly improved the presentation of this paper. The work is supported by the National Natural Science Foundation of China （No. 11261017）, the Key Laboratory of Biological Resources Protection and Utilization of Hubei Province （No. PKLHB1323） and the Key Project of Chinese Ministry of Education （No. 212111）.
文摘In the real world, the population systems are often subject to white noises and a system with such stochastic perturbations tends to be suitably modeled by stochastic differential equations. This paper is concerned with the dynamic behaviors of a delay stochastic competitive system. We first obtain the global existence of a unique positive solution of system. Later, we show that the solution of system will be stochastically ultimate boundedness. However, large noises may make the system extinct exponentially with probability one. Also, sufficient conditions for the global attractivity of system are established. FinMly, illustrated examples are given to show the effectiveness of the proposed criteria.
文摘A class of nonlinear two-species competitive singularly perturbed initial-boundary-value problems for reaction-diffusion systems are studied. Under suitable assumptions, by using the stretched variable, the formal asymptotic expansion for the problems is constructed. The uniform validity of the solution for initial-boundary-value problems is obtained by using the theory of differential inequalities.
基金the Natural Science Foundation of Fujian Province (Z0511014)the Foundation of Developing Science and Technology of Fuzhou University (2005-QX-18, 2005-QX-21).
文摘In this paper, we consider almost periodic discrete two-species competitive sys-tems. By using Lyapunov functional, the existence conditions and uniqueness of almost periodic solutions for the this type of systems are obtained.
基金supported by the Natural Science Foundation of Fujian Province(2011J01007)the Technology Innovation Platform Project of Fujian Province(2009J1007)
文摘A two species Lotka-Volterra competitive system with infinite delays and feedback controls is studied in this paper.By constructing a suitable Lyapunov functional,we show that if the Lotka-Volterra competitive system is bistable(in the absence of feedback controls),then by choosing some suitable values of feedback control variables,one of the species is driven to extinction while the other one becomes globally stable.Examples together with their numerical simulations are presented to verify the feasibility of our results.Our results not only improve but also complement those of Z.Li,M.A.Han and F.D.Chen[Influence of feedback controls on an autonomous Lotka-Volterra competitive system with infinite delays,Nonlinear Anal.:Real World Appl.,14(2013),402-413].
基金The research was supported by the Natural Science Foundation of Fujian Province(2019J01089)Program for New Century Excellent Talents in Fujian Province University(2017,2018).
文摘In this paper, we consider a discrete competitive system with BeddingtonDe Angelis functional response and the effect of toxic substances. By constructing some suitable Lyapunov type extinction functions, sufficient conditions which guarantee the extinction of a species and global attractivity of the other one are obtained. Our results not only supplement and improve but also generalize some existing ones. Numerical simulations show the feasibility of our results.
基金the National Natural Science Foundation of China (10471040)Program for New Century Excellent Talents in University (NCET050271)the Natural Science Foundation of North University of China (54)
文摘In this paper, the impulsive exploitation of two species periodic competitive system is considered. First, we show that this type of system with impulsive harvesting has a unique positive periodicsolution, which is globally asymptotically stable. Further, by choosing the maximum total revenues as the management objective, we investigate the optimal harvesting policies for periodic competitive system with impulsive harvesting. Finally, we obtain the optimal time to harvest and optimal population level.
文摘A competitive system on the n-rectangle： {x ∈ Rn： 0 ≤ xi ≤ li, i = 1,... ,n} was con- sidered, each species of which, in isolation, admits logistic growth with the hyperbolic structure saturation. It has an （n - 1）-dimensional invariant surface called carrying simplex E as a globe attractor, hence the long term dynamics of the system is com- pletely determined by the dynamics on E. For the three-dimensional system, the whole dynamical behavior was presented. It has a unique positive equilibrium point and any limit set is either an equilibrium point or a limit cycle. The system is permanent and it is proved that the number of periodic orbits is finite and non-periodic oscillation the May Leonard phenomenon does not exist. A criterion for the positive equilibrium to be globally asymptotically stable is provided. Whether there exist limit cycles or not remains open.
