Research Topics
| Azmy S AcklehSummaryAffiliation: University of Louisiana at Lafayette Country: USA Publications
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Detail Information
Publications
The global dynamics of a discrete juvenile-adult model with continuous and seasonal reproductionAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504, USA
J Biol Dyn 3:101-15. 2009..When this value is less than one, the population goes to extinction. Conditions on the birth rate where the population with seasonal breeding survives while the population with continuous breeding becomes extinct are provided...- Discrete three-stage population model: persistence and global stability resultsAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA, USA
J Biol Dyn 2:415-27. 2008..If it is larger than one the existence of a unique positive fixed point is proved and the persistence of the system is established. Finally, for certain parameter ranges global stability of the positive fixed point is proved... - A monotone approximation for a size-structured population model with a generalized environmentAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504 1010, USA
J Biol Dyn 1:305-19. 2007..A fully discretized numerical scheme based on these monotone sequences is presented and utilized to provide some numerical examples... - A three-stage discrete-time population model: continuous versus seasonal reproductionAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504 1010, USA
J Biol Dyn 1:291-304. 2007..This is different from the results obtained for a two-stage model discussed by Ackleh and Jang (J. Diff. Equ. Appl., 13, 261-274, 2007), where it was shown that for low birth rates seasonal breeding results in higher adult averages... - Stochastic juvenile--adult models with application to a green tree frog populationAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504 1010, USA
J Biol Dyn 5:64-83. 2011..These models are then used to understand the effect of demographic stochasticity on the dynamics of an urban green tree frog (Hyla cinerea) population... - Fitting a structured juvenile-adult model for green tree frogs to population estimates from capture-mark-recapture field dataAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504 1010, USA
Bull Math Biol 74:641-65. 2012..Numerical results for the model sensitivity with respect to these parameters are given. Finally, the above-mentioned parameter estimates are used to illustrate the long-time behavior of the population under investigation... - Stability of a delay equation arising from a juvenile-adult modelAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
Math Biosci Eng 7:729-37. 2010..We also show that under certain conditions the equation undergoes a Hopf bifurcation. We then study global asymptotic stability and present bifurcation diagrams for two special cases of the model... 
Parameter estimation in a coupled system of nonlinear size-structured populationsAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, Louisiana 70504 1010
Math Biosci Eng 2:289-315. 2005..Convergence results for the parameter estimation technique are established. Ample numerical simulations and statistical evidence are provided to demonstrate the feasibility of this approach...- Parameter estimation in a structured erythropoiesis modelAzmy S Ackleh
Department of Mathematics, University of Louisiana, Lafayette, Louisiana 70504, USA
Math Biosci Eng 5:601-16. 2008..Standard errors for such parameters are also given... - Comparison between stochastic and deterministic selection-mutation modelsAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, Louisiana 70504 1010, USA
Math Biosci Eng 4:133-57. 2007.... - Establishing a beachhead: a stochastic population model with an Allee effect applied to species invasionAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504 1010, USA
Theor Popul Biol 71:290-300. 2007..Furthermore, if migration rates are low, one or more than one patch may be successfully invaded, while if migration rates are high all patches are invaded... - A structured erythropoiesis model with nonlinear cell maturation velocity and hormone decay rateAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504 1010, USA
Math Biosci 204:21-48. 2006..A study of robustness with respect to the forms of these functions and parameter sensitivity is also carried out... - Competitive exclusion and coexistence for a quasilinear size-structured population modelAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504 1010, USA
Math Biosci 192:177-92. 2004..In particular, our results suggest that the ratio of the reproduction and mortality rates is a good measure to determine the winning ecotype. Meanwhile, we show that in the case of open reproduction all ecotypes coexist... - Competitive exclusion and coexistence for pathogens in an epidemic model with variable population sizeAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA 70504 1010, USA
J Math Biol 47:153-68. 2003..In addition, an example is given which shows that if such inequalities are not satisfied then coexistence may occur... - Assessing the Deepwater Horizon oil spill impact on marine mammal population through acoustics: endangered sperm whalesAzmy S Ackleh
Department of Mathematics, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, USA
J Acoust Soc Am 131:2306-14. 2012..This indicates that some sperm whales may have relocated farther away from the spill. Follow-up experiments will be important for understanding long-term impact... - Invasion, disturbance, and competition: modeling the fate of coastal plant populationsSharmila Pathikonda
Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA
Conserv Biol 23:164-73. 2009..Our models contribute new insight into the relationship between environmental disturbance and invasion and demonstrate how influential abiotic factors such as climate change will be in determining interspecific interactions...