Overcoming the impossibility of age-balanced harvest
Math Biosci. 2023 Nov 21:109111. doi: 10.1016/j.mbs.2023.109111. Online ahead of print.ABSTRACTIn many countries, sustainability targets for managed fisheries are often expressed in terms of a fixed percentage of the carrying capacity. Despite the appeal of such a simple quantitative target, an unintended consequence may be a significant tilting of the proportions of biomass across different ages, from what they would have been under harvest-free conditions. Within the framework of a widely used age-structured model, we propose a novel quantitative definition of "age-balanced harvest" that considers the age-class compositi...
Source: Mathematical Biosciences - November 23, 2023 Category: Statistics Authors: Jerzy A Filar Matthew H Holden Manuela Mendiolar Sabrina H Streipert Source Type: research
Pairwise and higher-order epistatic effects among somatic cancer mutations across oncogenesis
Math Biosci. 2023 Nov 21:109091. doi: 10.1016/j.mbs.2023.109091. Online ahead of print.ABSTRACTCancer occurs as a consequence of multiple somatic mutations that lead to uncontrolled cell growth. Mutual exclusivity and co-occurrence of mutations imply-but do not prove-that mutations exert synergistic or antagonistic epistatic effects on oncogenesis. Knowledge of these interactions, and the consequent trajectories of mutation and selection that lead to cancer has been a longstanding goal within the cancer research community. Recent research has revealed mutation rates and scaled selection coefficients for specific recurrent ...
Source: Mathematical Biosciences - November 23, 2023 Category: Statistics Authors: Jorge A Alfaro-Murillo Jeffrey P Townsend Source Type: research
Overcoming the impossibility of age-balanced harvest
Math Biosci. 2023 Nov 21:109111. doi: 10.1016/j.mbs.2023.109111. Online ahead of print.ABSTRACTIn many countries, sustainability targets for managed fisheries are often expressed in terms of a fixed percentage of the carrying capacity. Despite the appeal of such a simple quantitative target, an unintended consequence may be a significant tilting of the proportions of biomass across different ages, from what they would have been under harvest-free conditions. Within the framework of a widely used age-structured model, we propose a novel quantitative definition of "age-balanced harvest" that considers the age-class compositi...
Source: Mathematical Biosciences - November 23, 2023 Category: Statistics Authors: Jerzy A Filar Matthew H Holden Manuela Mendiolar Sabrina H Streipert Source Type: research
Pairwise and higher-order epistatic effects among somatic cancer mutations across oncogenesis
Math Biosci. 2023 Nov 21:109091. doi: 10.1016/j.mbs.2023.109091. Online ahead of print.ABSTRACTCancer occurs as a consequence of multiple somatic mutations that lead to uncontrolled cell growth. Mutual exclusivity and co-occurrence of mutations imply-but do not prove-that mutations exert synergistic or antagonistic epistatic effects on oncogenesis. Knowledge of these interactions, and the consequent trajectories of mutation and selection that lead to cancer has been a longstanding goal within the cancer research community. Recent research has revealed mutation rates and scaled selection coefficients for specific recurrent ...
Source: Mathematical Biosciences - November 23, 2023 Category: Statistics Authors: Jorge A Alfaro-Murillo Jeffrey P Townsend Source Type: research
Overcoming the impossibility of age-balanced harvest
Math Biosci. 2023 Nov 21:109111. doi: 10.1016/j.mbs.2023.109111. Online ahead of print.ABSTRACTIn many countries, sustainability targets for managed fisheries are often expressed in terms of a fixed percentage of the carrying capacity. Despite the appeal of such a simple quantitative target, an unintended consequence may be a significant tilting of the proportions of biomass across different ages, from what they would have been under harvest-free conditions. Within the framework of a widely used age-structured model, we propose a novel quantitative definition of "age-balanced harvest" that considers the age-class compositi...
Source: Mathematical Biosciences - November 23, 2023 Category: Statistics Authors: Jerzy A Filar Matthew H Holden Manuela Mendiolar Sabrina H Streipert Source Type: research
Vaccination compartmental epidemiological models for the delta and omicron SARS-CoV-2 variants
We present two classes of models that differ depending on the immunological properties of the variant. The first one is for the delta variant, where we do not follow the dynamics of the vaccinated individuals since infections of vaccinated individuals were rare. The second one for the far more contagious omicron variant incorporates the evolution of the infections within the vaccinated cohort. We explore comparisons with available data involving two possible classes of counts, fatalities and hospitalizations. We present our results for two regions, Andalusia and Switzerland (including the Principality of Liechtenstein), wh...
Source: Mathematical Biosciences - November 19, 2023 Category: Statistics Authors: J Cuevas-Maraver P G Kevrekidis Q Y Chen G A Kevrekidis Y Drossinos Source Type: research
Vaccination compartmental epidemiological models for the delta and omicron SARS-CoV-2 variants
We present two classes of models that differ depending on the immunological properties of the variant. The first one is for the delta variant, where we do not follow the dynamics of the vaccinated individuals since infections of vaccinated individuals were rare. The second one for the far more contagious omicron variant incorporates the evolution of the infections within the vaccinated cohort. We explore comparisons with available data involving two possible classes of counts, fatalities and hospitalizations. We present our results for two regions, Andalusia and Switzerland (including the Principality of Liechtenstein), wh...
Source: Mathematical Biosciences - November 19, 2023 Category: Statistics Authors: J Cuevas-Maraver P G Kevrekidis Q Y Chen G A Kevrekidis Y Drossinos Source Type: research
Nonlinear control designs and their application to cancer differentiation therapy
Math Biosci. 2023 Nov 7:109105. doi: 10.1016/j.mbs.2023.109105. Online ahead of print.ABSTRACTWe designed three new controllers: a sigmoid-based controller, a polynomial dynamic inversion-based controller, and a proportional-integral-derivative (PID) impulsive controller for cancer differentiation therapy. We compared these three controllers to existing control strategies to show the improvement in performance and compare their robustness. The sigmoid-based controller adds a sigmoid term associated with the error of the controlled state and a selected observed state. The sigmoid term is multiplied by a control gain, thereb...
Source: Mathematical Biosciences - November 9, 2023 Category: Statistics Authors: Yen-Che Hsiao Abhishek Dutta Source Type: research
A model for voles interference in cultivated orchards
Math Biosci. 2023 Nov 7;366:109107. doi: 10.1016/j.mbs.2023.109107. Online ahead of print.ABSTRACTWe consider a dynamical system involving seven populations to model the presence of voles in a cultivated orchard. The plant population is stratified by age (three groups) and by health status (being damaged or not). The last equation models the voles with a modified logistic equation with Allee effect, where the modification takes into account the disturbance provided by the human activity on the orchard. Both an analytical investigation and numerical simulations on a case study are presented. The latter support the observed ...
Source: Mathematical Biosciences - November 9, 2023 Category: Statistics Authors: Alberto Viscardi Sandro Bertolino Ezio Venturino Source Type: research
Nonlinear control designs and their application to cancer differentiation therapy
Math Biosci. 2023 Nov 7:109105. doi: 10.1016/j.mbs.2023.109105. Online ahead of print.ABSTRACTWe designed three new controllers: a sigmoid-based controller, a polynomial dynamic inversion-based controller, and a proportional-integral-derivative (PID) impulsive controller for cancer differentiation therapy. We compared these three controllers to existing control strategies to show the improvement in performance and compare their robustness. The sigmoid-based controller adds a sigmoid term associated with the error of the controlled state and a selected observed state. The sigmoid term is multiplied by a control gain, thereb...
Source: Mathematical Biosciences - November 9, 2023 Category: Statistics Authors: Yen-Che Hsiao Abhishek Dutta Source Type: research
A model for voles interference in cultivated orchards
Math Biosci. 2023 Nov 7;366:109107. doi: 10.1016/j.mbs.2023.109107. Online ahead of print.ABSTRACTWe consider a dynamical system involving seven populations to model the presence of voles in a cultivated orchard. The plant population is stratified by age (three groups) and by health status (being damaged or not). The last equation models the voles with a modified logistic equation with Allee effect, where the modification takes into account the disturbance provided by the human activity on the orchard. Both an analytical investigation and numerical simulations on a case study are presented. The latter support the observed ...
Source: Mathematical Biosciences - November 9, 2023 Category: Statistics Authors: Alberto Viscardi Sandro Bertolino Ezio Venturino Source Type: research
Nonlinear control designs and their application to cancer differentiation therapy
Math Biosci. 2023 Nov 7:109105. doi: 10.1016/j.mbs.2023.109105. Online ahead of print.ABSTRACTWe designed three new controllers: a sigmoid-based controller, a polynomial dynamic inversion-based controller, and a proportional-integral-derivative (PID) impulsive controller for cancer differentiation therapy. We compared these three controllers to existing control strategies to show the improvement in performance and compare their robustness. The sigmoid-based controller adds a sigmoid term associated with the error of the controlled state and a selected observed state. The sigmoid term is multiplied by a control gain, thereb...
Source: Mathematical Biosciences - November 9, 2023 Category: Statistics Authors: Yen-Che Hsiao Abhishek Dutta Source Type: research
A model for voles interference in cultivated orchards
Math Biosci. 2023 Nov 7;366:109107. doi: 10.1016/j.mbs.2023.109107. Online ahead of print.ABSTRACTWe consider a dynamical system involving seven populations to model the presence of voles in a cultivated orchard. The plant population is stratified by age (three groups) and by health status (being damaged or not). The last equation models the voles with a modified logistic equation with Allee effect, where the modification takes into account the disturbance provided by the human activity on the orchard. Both an analytical investigation and numerical simulations on a case study are presented. The latter support the observed ...
Source: Mathematical Biosciences - November 9, 2023 Category: Statistics Authors: Alberto Viscardi Sandro Bertolino Ezio Venturino Source Type: research
Nonlinear control designs and their application to cancer differentiation therapy
Math Biosci. 2023 Nov 7:109105. doi: 10.1016/j.mbs.2023.109105. Online ahead of print.ABSTRACTWe designed three new controllers: a sigmoid-based controller, a polynomial dynamic inversion-based controller, and a proportional-integral-derivative (PID) impulsive controller for cancer differentiation therapy. We compared these three controllers to existing control strategies to show the improvement in performance and compare their robustness. The sigmoid-based controller adds a sigmoid term associated with the error of the controlled state and a selected observed state. The sigmoid term is multiplied by a control gain, thereb...
Source: Mathematical Biosciences - November 9, 2023 Category: Statistics Authors: Yen-Che Hsiao Abhishek Dutta Source Type: research
A model for voles interference in cultivated orchards
Math Biosci. 2023 Nov 7;366:109107. doi: 10.1016/j.mbs.2023.109107. Online ahead of print.ABSTRACTWe consider a dynamical system involving seven populations to model the presence of voles in a cultivated orchard. The plant population is stratified by age (three groups) and by health status (being damaged or not). The last equation models the voles with a modified logistic equation with Allee effect, where the modification takes into account the disturbance provided by the human activity on the orchard. Both an analytical investigation and numerical simulations on a case study are presented. The latter support the observed ...
Source: Mathematical Biosciences - November 9, 2023 Category: Statistics Authors: Alberto Viscardi Sandro Bertolino Ezio Venturino Source Type: research
