In this paper, we study the existence and global asymptotic stability of positive periodic solutions of a delayed periodic predator-prey system with Hoffing Ⅱ type functional response. By use of the continuation theo...In this paper, we study the existence and global asymptotic stability of positive periodic solutions of a delayed periodic predator-prey system with Hoffing Ⅱ type functional response. By use of the continuation theorem of coincidence degree theory and the method of Lyapunov function, some sufficient conditions are obtained.展开更多
In this paper, a class of SEIQV epidemic model with general nonlinear incidence rate is investigated. By constructing Lyapunov function, it is shown that the disease-free equilibrium is globally asymptotically stable ...In this paper, a class of SEIQV epidemic model with general nonlinear incidence rate is investigated. By constructing Lyapunov function, it is shown that the disease-free equilibrium is globally asymptotically stable if the basic reproduction number R0 ≤ 1. If R0 〉 1, we show that the endemic equilibrium is globally asymptotically stable by applying Li and Muldowney geometric approach.展开更多
The inducible CRISPR activation(CRISPR-a)system offers unparalleled precision and versatility for regu-lating endogenous genes,making it highly sought after in plant research.In this study,we developed a chem-ically i...The inducible CRISPR activation(CRISPR-a)system offers unparalleled precision and versatility for regu-lating endogenous genes,making it highly sought after in plant research.In this study,we developed a chem-ically inducible CRISPR-a tool for plants called ER-Tag by combining the LexA-VP16-ER inducible system with the SunTag CRISPR-a system.We systematically compared different induction strategies and achieved high efficiency in target gene activation.We demonstrated that guide RNAs can be multiplexed and pooled for large-scale screening of effective morphogenic genes and gene pairs involved in plant regeneration.Further experiments showed that induced activation of these morphogenic genes can accelerate regenera-tion and improve regeneration efficiency in both eudicot and monocot plants,including alfalfa,woodland strawberry,and sheepgrass.Our study expands the CRISPR toolset in plants and provides a powerful new strategy for studying gene function when constitutive expression is not feasible or ideal.展开更多
基金This work is supported by Scientific Research Fund of ShanDong Agricultural University
文摘In this paper, we study the existence and global asymptotic stability of positive periodic solutions of a delayed periodic predator-prey system with Hoffing Ⅱ type functional response. By use of the continuation theorem of coincidence degree theory and the method of Lyapunov function, some sufficient conditions are obtained.
基金The first author was supported by Zhejiang Provincial Natural Science Foundation of China under Grant No. LQ14A010004.
文摘In this paper, a class of SEIQV epidemic model with general nonlinear incidence rate is investigated. By constructing Lyapunov function, it is shown that the disease-free equilibrium is globally asymptotically stable if the basic reproduction number R0 ≤ 1. If R0 〉 1, we show that the endemic equilibrium is globally asymptotically stable by applying Li and Muldowney geometric approach.
基金supported by the National Key R&D Program of China (2022YFD1500503 to X.S.)the Key Projects in Science and Technology of Inner Mongolia (2021ZD0031 to X.C.and S.Z.)+6 种基金the National Key Research and Development Program (2022YFF1002802 to X.D.)the Youth Innovation Promotion Association,CAS (Y2022039 to X.D.)the Youth Innovation Promotion Association,CAS (2022096 to S.Z.)the National Science Foundation of China (NSFC32272692 to J.Z.)Project ZR2022QC054 of the Shandong Provincial Natural Science Foundation (to Y.T.)funding from the State Key Laboratory of Protein and Plant Gene Research (to Q.L.).
文摘The inducible CRISPR activation(CRISPR-a)system offers unparalleled precision and versatility for regu-lating endogenous genes,making it highly sought after in plant research.In this study,we developed a chem-ically inducible CRISPR-a tool for plants called ER-Tag by combining the LexA-VP16-ER inducible system with the SunTag CRISPR-a system.We systematically compared different induction strategies and achieved high efficiency in target gene activation.We demonstrated that guide RNAs can be multiplexed and pooled for large-scale screening of effective morphogenic genes and gene pairs involved in plant regeneration.Further experiments showed that induced activation of these morphogenic genes can accelerate regenera-tion and improve regeneration efficiency in both eudicot and monocot plants,including alfalfa,woodland strawberry,and sheepgrass.Our study expands the CRISPR toolset in plants and provides a powerful new strategy for studying gene function when constitutive expression is not feasible or ideal.
