To better understand the diversity of metal resistance genetic determinant from microbes that survived at metal tailings in northwest of China, a highly elevated level of heavy metal containing region, genomic analyse...To better understand the diversity of metal resistance genetic determinant from microbes that survived at metal tailings in northwest of China, a highly elevated level of heavy metal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria（PGPB）. It shows that： Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF（Cation Diffusion Facilitator）, Hup E/Ure J and CHR（chromate ion transporter） family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative Cop A/Cue O system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while Znt A transporter, assisted with putative Czc D, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid（IAA） secretion,indicating a potential in-site phytoremediation usage in the mining tailing regions of China.展开更多
This paper formulates an SEIRSHM epidemic model with general birth rate,media report and limited medical resources.Firstly,the well-posedness of the solutions and the extinction of the disease are discussed.Then,the e...This paper formulates an SEIRSHM epidemic model with general birth rate,media report and limited medical resources.Firstly,the well-posedness of the solutions and the extinction of the disease are discussed.Then,the existence of the endemic equilibrium is discussed and we find when R^(*)>1 and R0=1,there exhibits a backward bifurcation,if R^(*)<1 and R0=1,there exhibits a forward bifurcation.Finally,numerical simulations are carried out to illustrate the main results and show that media report and limited medical resources have a great impact on disease transmission.展开更多
In this paper,a SVEIRDP epidemic model is proposed to investigate the transmission dynamics of Ebola by cumulative release from the infected individuals and corpses in the form of infinite integrals.First,the positivi...In this paper,a SVEIRDP epidemic model is proposed to investigate the transmission dynamics of Ebola by cumulative release from the infected individuals and corpses in the form of infinite integrals.First,the positivity and ultimate boundedness of solutions are proved.Second,the basic reproduction number R0 is calculated.Furthermore,it is proven that if R0<1,the model has the disease-free equilibrium and is globally asymptotically stable(GAS);If R0>1,the unique endemic equilibrium is GAS.To clearly illustrate the theoretical results,real data are used to conduct numerical simulations.We discover that modeling the cumulative release of Ebola from the infected individuals and corpses using the infinite integral with an appropriate probability density function(PDF)provides a more realistic and accurate representation of the actual disease spread.展开更多
In this paper,we study an SS_(v)EIQR model with nonlinear contact rate,isolation rate and vaccination rate driven by media coverage.First,the basic reproduction number R_(0)is derived.Then,the threshold dynamics of th...In this paper,we study an SS_(v)EIQR model with nonlinear contact rate,isolation rate and vaccination rate driven by media coverage.First,the basic reproduction number R_(0)is derived.Then,the threshold dynamics of the disease are obtained in terms of R_(0):when R_(0)≤1,the global stability of the disease-free equilibrium is obtained by constructing an appropriate Lyapunov function;when R_(0)>1,the sufficient conditions to prove the globally stability of endemic equilibrium are obtained by applying the geometric method into the four-dimensional system,which needs to estimate the Lozinskii measure of a 6×6 matrix.Further,we conduct some numerical simulations to validate our theoretical results,and analyze the impact of media coverage on disease transmission,the results show that media coverage could effectively suppress the spread of the disease and reduce the number of infected individuals.Finally,through the sensitivity analysis of R_(0),we obtain some measures to control the spread of the disease,such as reducing contact,strengthening isolation and vaccination.展开更多
In this paper,a stochastic delayed differential algebraic predator-prey model with Michaelis-Menten-type prey harvesting is proposed.Due to the influence of gestation delay and stochastic fluctuations,the proposed mod...In this paper,a stochastic delayed differential algebraic predator-prey model with Michaelis-Menten-type prey harvesting is proposed.Due to the influence of gestation delay and stochastic fluctuations,the proposed model displays a complex dynamics.Criteria on the local stability of the interior equilibrium are established,and the effect of gestation delay on the model dynamics is discussed.Taking the gestation delay and economic profit as bifurcation parameters,Hopf bifurcation and singularity induced bifurcation can occur as they cross through some critical values,respectively.Moreover,the solution of the model will blow up in a limited time when delay τ>τ0.Then,we calculate the fluctuation intensity of the stochastic fluctuations by Fourier transform method,which is the key to illustrate the effect of stochastic fluctuations.Finally,we demonstrate our theoretical results by numerical simulations.展开更多
基金supported by the National High Technology Research and Development Program (863) of China (No.2012AA101402)the National Science Foundation of China (Nos.31125007,31370142)
文摘To better understand the diversity of metal resistance genetic determinant from microbes that survived at metal tailings in northwest of China, a highly elevated level of heavy metal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria（PGPB）. It shows that： Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF（Cation Diffusion Facilitator）, Hup E/Ure J and CHR（chromate ion transporter） family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative Cop A/Cue O system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while Znt A transporter, assisted with putative Czc D, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid（IAA） secretion,indicating a potential in-site phytoremediation usage in the mining tailing regions of China.
基金supported by the National Natural Science Foundation(12201540)the Natural Science Foundation of Xinjiang Uygur Autonomous Region,China(2022D01C64)the Doctoral Research Initiation Fund of Xinjiang University,China(620320024).
文摘This paper formulates an SEIRSHM epidemic model with general birth rate,media report and limited medical resources.Firstly,the well-posedness of the solutions and the extinction of the disease are discussed.Then,the existence of the endemic equilibrium is discussed and we find when R^(*)>1 and R0=1,there exhibits a backward bifurcation,if R^(*)<1 and R0=1,there exhibits a forward bifurcation.Finally,numerical simulations are carried out to illustrate the main results and show that media report and limited medical resources have a great impact on disease transmission.
基金supported by the Natural Science Foundation of China(Grant No.12261087,12371504,12201540)the Natural Science Foundation of Xinjiang,China(Grant No.2022D01E41)+1 种基金the Leading Talents of Tianshan Project in Xinjiang Uygur Autonomous Region,China(Grant No.2023TSYCLJ0054)the Open Project of Key Laboratory of Applied Mathematics of Xinjiang,China(Grant No.2021D04014).
文摘In this paper,a SVEIRDP epidemic model is proposed to investigate the transmission dynamics of Ebola by cumulative release from the infected individuals and corpses in the form of infinite integrals.First,the positivity and ultimate boundedness of solutions are proved.Second,the basic reproduction number R0 is calculated.Furthermore,it is proven that if R0<1,the model has the disease-free equilibrium and is globally asymptotically stable(GAS);If R0>1,the unique endemic equilibrium is GAS.To clearly illustrate the theoretical results,real data are used to conduct numerical simulations.We discover that modeling the cumulative release of Ebola from the infected individuals and corpses using the infinite integral with an appropriate probability density function(PDF)provides a more realistic and accurate representation of the actual disease spread.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2022D01C64,2022D01C699)Natural Science Foundation of China(12201540)the Doctoral Foundation of Xinjiang University(620320024).
文摘In this paper,we study an SS_(v)EIQR model with nonlinear contact rate,isolation rate and vaccination rate driven by media coverage.First,the basic reproduction number R_(0)is derived.Then,the threshold dynamics of the disease are obtained in terms of R_(0):when R_(0)≤1,the global stability of the disease-free equilibrium is obtained by constructing an appropriate Lyapunov function;when R_(0)>1,the sufficient conditions to prove the globally stability of endemic equilibrium are obtained by applying the geometric method into the four-dimensional system,which needs to estimate the Lozinskii measure of a 6×6 matrix.Further,we conduct some numerical simulations to validate our theoretical results,and analyze the impact of media coverage on disease transmission,the results show that media coverage could effectively suppress the spread of the disease and reduce the number of infected individuals.Finally,through the sensitivity analysis of R_(0),we obtain some measures to control the spread of the disease,such as reducing contact,strengthening isolation and vaccination.
基金This work was supported by the Natural Science Foundation of China(Grant Nos.11861065,11771373 and 11961066)the Natural Science Foundation of Xinjiang Province of China(Grant No.2019D01C076)+2 种基金The Doctoral innovation project of Xinjiang University(XJUBSCX-2017005)the graduate research innovation project of Xinjiang Province(XJ2019G007)the China Scholarship Council under a joint-training program at Memorial University of Newfoundland(201907010023).
文摘In this paper,a stochastic delayed differential algebraic predator-prey model with Michaelis-Menten-type prey harvesting is proposed.Due to the influence of gestation delay and stochastic fluctuations,the proposed model displays a complex dynamics.Criteria on the local stability of the interior equilibrium are established,and the effect of gestation delay on the model dynamics is discussed.Taking the gestation delay and economic profit as bifurcation parameters,Hopf bifurcation and singularity induced bifurcation can occur as they cross through some critical values,respectively.Moreover,the solution of the model will blow up in a limited time when delay τ>τ0.Then,we calculate the fluctuation intensity of the stochastic fluctuations by Fourier transform method,which is the key to illustrate the effect of stochastic fluctuations.Finally,we demonstrate our theoretical results by numerical simulations.
