In this paper, the dynamical behaviors of a modified Leslie-Gower predator-prey model incorporating fear effect and prey refuge are investigated. We delve into the construction of the model and its biological signific...In this paper, the dynamical behaviors of a modified Leslie-Gower predator-prey model incorporating fear effect and prey refuge are investigated. We delve into the construction of the model and its biological significance, with preliminary results encompassing positivity, boundedness, and persistence. The stability of the system’s boundary and positive equilibrium points is proven by calculating the real part of the eigenvalues of the Jacobian matrix. At the positive equilibrium point, we demonstrate that the system’s unique positive equilibrium is globally asymptotically stable by using the Dulac criterion. Furthermore, at this equilibrium point, we employ the Implicit Function Theorem to discuss how fear effects and prey refuges influence the population densities of both prey and predators. Finally, numerical simulations are conducted to validate the above-mentioned conclusions and explored the impact of Predator-taxis sensitivity αon dynamics of the system.展开更多
In this paper, the dynamic properties of a discrete predator-prey model are discussed. The properties of non-hyperbolic fixed points and hyperbolic fixed points of the model are analyzed. First, by using the classic S...In this paper, the dynamic properties of a discrete predator-prey model are discussed. The properties of non-hyperbolic fixed points and hyperbolic fixed points of the model are analyzed. First, by using the classic Shengjin formula, we find the existence conditions for fixed points of the model. Then, by using the qualitative theory of ordinary differential equations and matrix theory we indicate which points are hyperbolic and which are non-hyperbolic and the associated conditions.展开更多
Recent advances in our understanding of avian chemical communication have highlighted the importance of olfaction in many aspects of avian life.Prior studies investigating predator avoidance behaviors in response to p...Recent advances in our understanding of avian chemical communication have highlighted the importance of olfaction in many aspects of avian life.Prior studies investigating predator avoidance behaviors in response to predator odor cues have produced mixed results across species and contexts.Here we assess if a community of birds in eastern Pennsylvania displays avoidance behaviors towards predator odor cues in a natural foraging setting.We use clay caterpillars to measure foraging activity by birds in the presence of predator(bobcat)urine,non-predator(rabbit)urine,and water controls in two different environmental contexts(field vs.forest).Although we detected a weak trend for birds to forage less at predator urine-treated sites,we found no significant difference in avian foraging between the site types.We did find that foraging rates between environmental contexts changed significantly over the course of the experiment,with forest sites showing decreasing foraging rates and field sites showing increasing foraging rates.Our results reinforce the published literature that avoidance of predator odors by birds may not be ubiquitous across contexts and species.展开更多
In blood or bone marrow,leukemia is a form of cancer.A person with leukemia has an expansion of white blood cells(WBCs).It primarily affects children and rarely affects adults.Treatment depends on the type of leukemia...In blood or bone marrow,leukemia is a form of cancer.A person with leukemia has an expansion of white blood cells(WBCs).It primarily affects children and rarely affects adults.Treatment depends on the type of leukemia and the extent to which cancer has established throughout the body.Identifying leukemia in the initial stage is vital to providing timely patient care.Medical image-analysis-related approaches grant safer,quicker,and less costly solutions while ignoring the difficulties of these invasive processes.It can be simple to generalize Computer vision(CV)-based and image-processing techniques and eradicate human error.Many researchers have implemented computer-aided diagnosticmethods andmachine learning(ML)for laboratory image analysis,hopefully overcoming the limitations of late leukemia detection and determining its subgroups.This study establishes a Marine Predators Algorithm with Deep Learning Leukemia Cancer Classification(MPADL-LCC)algorithm onMedical Images.The projectedMPADL-LCC system uses a bilateral filtering(BF)technique to pre-process medical images.The MPADL-LCC system uses Faster SqueezeNet withMarine Predators Algorithm(MPA)as a hyperparameter optimizer for feature extraction.Lastly,the denoising autoencoder(DAE)methodology can be executed to accurately detect and classify leukemia cancer.The hyperparameter tuning process using MPA helps enhance leukemia cancer classification performance.Simulation results are compared with other recent approaches concerning various measurements and the MPADL-LCC algorithm exhibits the best results over other recent approaches.展开更多
According to one of the theses of optimal foraging theory,main prey species abundance in the hunting area is the main factor determining the diet and habitat choices of birds of prey.However other factors can also be ...According to one of the theses of optimal foraging theory,main prey species abundance in the hunting area is the main factor determining the diet and habitat choices of birds of prey.However other factors can also be important.The habitat structure influences the predators’diets as well.In this study we examined the influence of habitat structure on diet compositions of three species of birds:Long-eared Owl(Asio otus),Short-eared Owl(A.flammeus)and Common Kestrel(Falco tinnunculus).The study was carried out from 2007 to 2019 in a 48 km2area of the Crane’s Homeland Reserve,Moscow Region,Russia.The habitat structures of model species’hunting territories(ratio of different types of landscape elements)were classified in module"Semi-Automatic Classification Plugin"based on the QGIS.A boosted regression tree analysis identified that the share of the main prey species in the diet is primarily determined by the landscape structure of hunting territories.The largest share of Common Vole(Microtus arvalis)in birds’diet was determined by the shrubs area(15%of hunting area),the meadow area(75%),the habitat heterogeneity(70%)and the arable land area(5%).The same predictors determined the largest share of Root Vole(Microtus oeconomus):the shrubs area 25%,the meadow area 70%,and the arable land area 3%.The annual mean abundance of prey species did not determine their importance in the diet of birds of prey.Thus,the main prey abundance in the hunting area is not a determining factor for the formation of diet composition of birds of prey.展开更多
A predator-prey model with linear capture term Holling-II functional response was studied by using differential equation theory. The existence and the stabilities of non-negative equilibrium points of the model were d...A predator-prey model with linear capture term Holling-II functional response was studied by using differential equation theory. The existence and the stabilities of non-negative equilibrium points of the model were discussed. The results show that under certain limited conditions, these two groups can maintain a balanced position, which provides a theoretical reference for relevant departments to make decisions on ecological protection.展开更多
In this paper, we prove the existence of forced waves for Leslie-Gower prey-predator model with nonlocal effects under shifting environment. By constructing a pair of upper and lower solutions with the method of monot...In this paper, we prove the existence of forced waves for Leslie-Gower prey-predator model with nonlocal effects under shifting environment. By constructing a pair of upper and lower solutions with the method of monotone iteration, we can obtain the existence of forced waves for any positive constant shifting speed. Finally, we show the asymptotical behavior of traveling wave fronts in two tails.展开更多
In this paper, we propose a discrete ratio-dependent predator-prey system. The stability of the fixed points of this model is studied. At the same time, it is shown that the discrete model undergoes fold bifurcation a...In this paper, we propose a discrete ratio-dependent predator-prey system. The stability of the fixed points of this model is studied. At the same time, it is shown that the discrete model undergoes fold bifurcation and flip bifurcation by using bifurcation theory and the method of approximation by a flow. Numerical simulations are presented not only to demonstrate the consistence with our theoretical analyses, but also to exhibit the complex dynamical behaviors, such as the cascade of period-doubling bifurcation in period-2 and the chaotic sets. The Maximum Lyapunov exponents are numerically computed to confirm further the complexity of the dynamical behaviors. These results show that the direct discrete method has more rich dynamic behaviors than the discrete model obtained by Euler method.展开更多
A class of nonlinear predator prey reaction diffusion systems for singularly pe rturbed problems are considered.Under suitable conditions, by using theory of di fferential inequalities the existence and asymptotic be...A class of nonlinear predator prey reaction diffusion systems for singularly pe rturbed problems are considered.Under suitable conditions, by using theory of di fferential inequalities the existence and asymptotic behavior of solution for in itial boundary value problems are studied.展开更多
In this paper, the existence o f a positive periodic solution to the following neutral predator_prey system (t)=rH(t)1-a 1(t)H(t-τ)+a 2(t-τ)K-α(t)H(t)P(t), (t)=-b(t)P(t)+β(t)H(t)P(t) is studied,in which ...In this paper, the existence o f a positive periodic solution to the following neutral predator_prey system (t)=rH(t)1-a 1(t)H(t-τ)+a 2(t-τ)K-α(t)H(t)P(t), (t)=-b(t)P(t)+β(t)H(t)P(t) is studied,in which r,a 2,K and τ are positive constants, and a 1(t ),α(t),b(t) and β(t) are positive continuous functions of period ω .展开更多
By using the continuation theorem of coincidence degree theory, sufficient conditions are obtained for the existence of positive periodic solutions of a delayed predator prey system with nonmonotonic functional respon...By using the continuation theorem of coincidence degree theory, sufficient conditions are obtained for the existence of positive periodic solutions of a delayed predator prey system with nonmonotonic functional response in a periodic environment.展开更多
文摘In this paper, the dynamical behaviors of a modified Leslie-Gower predator-prey model incorporating fear effect and prey refuge are investigated. We delve into the construction of the model and its biological significance, with preliminary results encompassing positivity, boundedness, and persistence. The stability of the system’s boundary and positive equilibrium points is proven by calculating the real part of the eigenvalues of the Jacobian matrix. At the positive equilibrium point, we demonstrate that the system’s unique positive equilibrium is globally asymptotically stable by using the Dulac criterion. Furthermore, at this equilibrium point, we employ the Implicit Function Theorem to discuss how fear effects and prey refuges influence the population densities of both prey and predators. Finally, numerical simulations are conducted to validate the above-mentioned conclusions and explored the impact of Predator-taxis sensitivity αon dynamics of the system.
文摘In this paper, the dynamic properties of a discrete predator-prey model are discussed. The properties of non-hyperbolic fixed points and hyperbolic fixed points of the model are analyzed. First, by using the classic Shengjin formula, we find the existence conditions for fixed points of the model. Then, by using the qualitative theory of ordinary differential equations and matrix theory we indicate which points are hyperbolic and which are non-hyperbolic and the associated conditions.
文摘Recent advances in our understanding of avian chemical communication have highlighted the importance of olfaction in many aspects of avian life.Prior studies investigating predator avoidance behaviors in response to predator odor cues have produced mixed results across species and contexts.Here we assess if a community of birds in eastern Pennsylvania displays avoidance behaviors towards predator odor cues in a natural foraging setting.We use clay caterpillars to measure foraging activity by birds in the presence of predator(bobcat)urine,non-predator(rabbit)urine,and water controls in two different environmental contexts(field vs.forest).Although we detected a weak trend for birds to forage less at predator urine-treated sites,we found no significant difference in avian foraging between the site types.We did find that foraging rates between environmental contexts changed significantly over the course of the experiment,with forest sites showing decreasing foraging rates and field sites showing increasing foraging rates.Our results reinforce the published literature that avoidance of predator odors by birds may not be ubiquitous across contexts and species.
基金funded by Researchers Supporting Program at King Saud University,(RSPD2024R809).
文摘In blood or bone marrow,leukemia is a form of cancer.A person with leukemia has an expansion of white blood cells(WBCs).It primarily affects children and rarely affects adults.Treatment depends on the type of leukemia and the extent to which cancer has established throughout the body.Identifying leukemia in the initial stage is vital to providing timely patient care.Medical image-analysis-related approaches grant safer,quicker,and less costly solutions while ignoring the difficulties of these invasive processes.It can be simple to generalize Computer vision(CV)-based and image-processing techniques and eradicate human error.Many researchers have implemented computer-aided diagnosticmethods andmachine learning(ML)for laboratory image analysis,hopefully overcoming the limitations of late leukemia detection and determining its subgroups.This study establishes a Marine Predators Algorithm with Deep Learning Leukemia Cancer Classification(MPADL-LCC)algorithm onMedical Images.The projectedMPADL-LCC system uses a bilateral filtering(BF)technique to pre-process medical images.The MPADL-LCC system uses Faster SqueezeNet withMarine Predators Algorithm(MPA)as a hyperparameter optimizer for feature extraction.Lastly,the denoising autoencoder(DAE)methodology can be executed to accurately detect and classify leukemia cancer.The hyperparameter tuning process using MPA helps enhance leukemia cancer classification performance.Simulation results are compared with other recent approaches concerning various measurements and the MPADL-LCC algorithm exhibits the best results over other recent approaches.
文摘According to one of the theses of optimal foraging theory,main prey species abundance in the hunting area is the main factor determining the diet and habitat choices of birds of prey.However other factors can also be important.The habitat structure influences the predators’diets as well.In this study we examined the influence of habitat structure on diet compositions of three species of birds:Long-eared Owl(Asio otus),Short-eared Owl(A.flammeus)and Common Kestrel(Falco tinnunculus).The study was carried out from 2007 to 2019 in a 48 km2area of the Crane’s Homeland Reserve,Moscow Region,Russia.The habitat structures of model species’hunting territories(ratio of different types of landscape elements)were classified in module"Semi-Automatic Classification Plugin"based on the QGIS.A boosted regression tree analysis identified that the share of the main prey species in the diet is primarily determined by the landscape structure of hunting territories.The largest share of Common Vole(Microtus arvalis)in birds’diet was determined by the shrubs area(15%of hunting area),the meadow area(75%),the habitat heterogeneity(70%)and the arable land area(5%).The same predictors determined the largest share of Root Vole(Microtus oeconomus):the shrubs area 25%,the meadow area 70%,and the arable land area 3%.The annual mean abundance of prey species did not determine their importance in the diet of birds of prey.Thus,the main prey abundance in the hunting area is not a determining factor for the formation of diet composition of birds of prey.
文摘A predator-prey model with linear capture term Holling-II functional response was studied by using differential equation theory. The existence and the stabilities of non-negative equilibrium points of the model were discussed. The results show that under certain limited conditions, these two groups can maintain a balanced position, which provides a theoretical reference for relevant departments to make decisions on ecological protection.
文摘In this paper, we prove the existence of forced waves for Leslie-Gower prey-predator model with nonlocal effects under shifting environment. By constructing a pair of upper and lower solutions with the method of monotone iteration, we can obtain the existence of forced waves for any positive constant shifting speed. Finally, we show the asymptotical behavior of traveling wave fronts in two tails.
文摘In this paper, we propose a discrete ratio-dependent predator-prey system. The stability of the fixed points of this model is studied. At the same time, it is shown that the discrete model undergoes fold bifurcation and flip bifurcation by using bifurcation theory and the method of approximation by a flow. Numerical simulations are presented not only to demonstrate the consistence with our theoretical analyses, but also to exhibit the complex dynamical behaviors, such as the cascade of period-doubling bifurcation in period-2 and the chaotic sets. The Maximum Lyapunov exponents are numerically computed to confirm further the complexity of the dynamical behaviors. These results show that the direct discrete method has more rich dynamic behaviors than the discrete model obtained by Euler method.
基金Supported by important study project of the National Natural Science Foundation of China(9 0 2 1 1 0 0 4 ) and by the"Hundred Talents'Project"of Chinese Academy of Sciences
文摘A class of nonlinear predator prey reaction diffusion systems for singularly pe rturbed problems are considered.Under suitable conditions, by using theory of di fferential inequalities the existence and asymptotic behavior of solution for in itial boundary value problems are studied.
文摘In this paper, the existence o f a positive periodic solution to the following neutral predator_prey system (t)=rH(t)1-a 1(t)H(t-τ)+a 2(t-τ)K-α(t)H(t)P(t), (t)=-b(t)P(t)+β(t)H(t)P(t) is studied,in which r,a 2,K and τ are positive constants, and a 1(t ),α(t),b(t) and β(t) are positive continuous functions of period ω .
文摘By using the continuation theorem of coincidence degree theory, sufficient conditions are obtained for the existence of positive periodic solutions of a delayed predator prey system with nonmonotonic functional response in a periodic environment.
