{"title":"Average-delay impulsive control for synchronization of uncertain chaotic neural networks with variable delay impulses.","authors":"Biwen Li, Yujie Liu","doi":"10.3934/mbe.2025052","DOIUrl":"https://doi.org/10.3934/mbe.2025052","url":null,"abstract":"<p><p>This paper investigated the synchronization issue of uncertain chaotic neural networks (CNNs) using a delayed impulsive control approach. To address the disturbances caused by parameter uncertainty and the flexibility of impulsive delays, the concept of average impulsive delay (AID) and average impulsive interval (AII) were utilized to handle the delays as a whole. Under the condition that the norms of uncertain parameters are bounded, the synchronization criteria for uncertain CNNs were derived based on linear matrix inequalities (LMIs). Specifically, we relaxed the constraints on the delay in the impulsive control inputs, thus allowing it to flexibly vary without being bound by some conditions, which provides a broader applicability compared to most existing results. Additionally, the results show that delayed impulses can facilitate the synchronization of uncertain CNNs. Finally, the validity of the theoretical results was verified through a numerical example.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 6","pages":"1382-1398"},"PeriodicalIF":2.6,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144660890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mayra Núñez-López, Jocelyn A Castro-Echeverría, Jorge X Velasco-Hernández
{"title":"Dynamic interaction between transmission, within-host dynamics and mosquito density.","authors":"Mayra Núñez-López, Jocelyn A Castro-Echeverría, Jorge X Velasco-Hernández","doi":"10.3934/mbe.2025051","DOIUrl":"https://doi.org/10.3934/mbe.2025051","url":null,"abstract":"<p><p>The central question in this paper is the character and role of the within-host and between-host interactions in vector-transmitted diseases compared to environmental-transmitted diseases. In vector-transmitted diseases, the environmental stage becomes the vector population. We link an epidemiological model for a vector-transmitted disease with a simple immunological process: the effective transmission rate from host to vector, modeled as a function of the infected cell level within the host, and a virus inoculation term that depends on the abundance of infected mosquitoes. We explore the role of infectivity (defined as the number of host target cells infected), recovery rate, and viral clearance rate in the coupled dynamics of these systems. As expected, the conditions for a disease outbreak require the average individual in the population to have an active (within-host) viral infection. However, the outbreak's nature, duration, and dynamic characteristics depend on the intensity of the within-host infection and the nature of the mosquito transmission capacity. Through the model, we establish inter-relations between the infectivity, host recovery rate, viral clearance rate, and different dynamic behavior patterns at the population level.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 6","pages":"1364-1381"},"PeriodicalIF":2.6,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144660892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamical system of quokka population depicting Fennecaphobia by Vulpes vulpes.","authors":"Sangeeta Kumari, Sidharth Menon, Abhirami K","doi":"10.3934/mbe.2025050","DOIUrl":"https://doi.org/10.3934/mbe.2025050","url":null,"abstract":"<p><p>A spatio-temporal prey-predator (quokka and red fox interaction) model with the fear effect, Holling type Ⅱ functional response, and a generalist predator is proposed. The existence of equilibrium points and their corresponding stability are analyzed under certain conditions to explore the system's dynamics. The occurrence of a Hopf bifurcation, a saddle-node bifurcation, and a Bogdanov-Takens bifurcation are confirmed. The partial rank correlation coefficient method is performed for the sensitivity analysis. Furthermore, the cross-diffusion is incorporated in the formulated model system to identify the spatio-temporal dynamics of the system. All theoretical results are validated through a numerical simulation. The outcome of the temporal model shows a decrease in the fear effect due to the predation by the red fox helps to increase the quokka population. The spatio-temporal model indicates that as the diffusion coefficient and fear parameters vary, the pattern changes from isolated spots to stripes, and again from stripes to spots. This represents the variation in spatial interactions and aggregation. The dispersion of predators and prey increases with an increased diffusion; however, the group formation is restricted by a stronger fear effect that scatters prey.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 6","pages":"1342-1363"},"PeriodicalIF":2.6,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144660893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Budget allocation and illegal fishing: a game theoretic approach.","authors":"Maggie R Sullens, Nina H Fefferman","doi":"10.3934/mbe.2025049","DOIUrl":"https://doi.org/10.3934/mbe.2025049","url":null,"abstract":"<p><p>Conservation efforts are under constant threat of failure due to poaching. Efforts to combat poaching may take a number of forms, but access to each form depends on resources, and access to these resources may depend on the success of previous efforts (e.g., monetary donations from supporters could directly combat poaching, but may be more effective if partially spent on recruiting additional supporters who then also donate). We adopted a mathematical framework with inspiration from the famous colonel blotto game to model the ongoing battle between conservationists and poachers. Focusing on a marine setting as a case study, players have budgets consisting of three types of resources: monetary, non-monetary, and supporters. The heterogeneous battlefields (laws, marine reserves, and community) reflect commonly employed conservation tactics meant to limit poaching. conservationists allocate resources to limit the success of poachers, while poachers allocate resources to overcome barriers implemented by conservationists. We assumed that no action can succeed without supporters, and thus whichever player wins over all the supporters in the community (i.e., the community battlefield), wins the game. We analyzed battlefield payoffs and player budget distributions to determine overall player success. We demonstrated how initially disadvantaged players may have an opportunity to win the game, although, we found that success in the first round can be most critical under certain scenarios. By framing the question in this way, we hope to provide additional tools for decision support to guide resource allocation, improving the efficacy of conservation efforts.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 6","pages":"1307-1341"},"PeriodicalIF":2.6,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144660891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Darwinian version of the Leslie logistic model for age-structured populations.","authors":"George Th Ellison, Hanan Rhoma","doi":"10.3934/mbe.2025048","DOIUrl":"10.3934/mbe.2025048","url":null,"abstract":"<p><p>In this review, we explore the advances, setbacks, and future possibilities of directed acyclic graphs (DAGs) as conceptual and analytical tools in applied and theoretical epidemiology. DAGs are literal, theoretical or speculative, and diagrammatic representations of known, uncertain, or unknown data generating mechanisms (and dataset generating processes) in which the causal relationships between variables are determined on the basis of two over-riding principles-\"directionality\" and \"acyclicity\". Among the many strengths of DAGs are their transparency, simplicity, flexibility, methodological utility, and epistemological credibility. All these strengths can help applied epidemiological studies better mitigate (and acknowledge) the impact of avoidable (and unavoidable) biases in causal inference analyses based on observational/non-experimental data. They can also strengthen the credibility and utility of theoretical studies that use DAGs to identify and explore hitherto hidden sources of analytical and inferential bias. Nonetheless, and despite their apparent simplicity, the application of DAGs has suffered a number of setbacks due to weaknesses in understanding, practice, and reporting. These include a failure to include all possible (conceivable and inconceivable) unmeasured covariates when developing and specifying DAGs; and weaknesses in the reporting of DAGs containing more than a handful of variables and paths, and where the intended application(s) and rationale(s) involved is necessary for appreciating, evaluating, and exploiting any causal insights they might offer. We proposed two additional principles to address these weaknesses and identify a number of opportunities where DAGs might lead to further advancements: The critical appraisal and synthesis of observational studies; the external validity and portability of causality-informed prediction; the identification of novel sources of bias; and the application of DAG-dataset consistency assessment to resolve pervasive uncertainty in the temporal positioning of time-variant and time-invariant exposures, outcomes, and covariates.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 6","pages":"1280-1306"},"PeriodicalIF":2.6,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144660889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Darwinian version of the Leslie logistic model for age-structured populations.","authors":"Jim M Cushing","doi":"10.3934/mbe.2025047","DOIUrl":"https://doi.org/10.3934/mbe.2025047","url":null,"abstract":"<p><p>The known global dynamics of the classic Leslie logistic model for the dynamics of an age-structured population are extended to a Darwinian dynamic version of the model for a single phenotypic trait (that is subject to natural selection). This is done under the assumption that the speed of evolution does not exceed an upper bound and that the maximum intraspecific competition intensity experienced by an individual occurs when its inherited trait equals that of the population mean trait. An example is given that applies the results to a model in which age-specific birth rates are subject to natural selection and that illustrates conditions under which evolution favors an iteroparous-type or a semelparous-type of life history strategy.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 6","pages":"1263-1279"},"PeriodicalIF":2.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144660888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Using mathematical modeling to study the dynamics of Legionnaires' disease and consider management options.","authors":"Mark Z Wang, Christina J Edholm, Lihong Zhao","doi":"10.3934/mbe.2025045","DOIUrl":"https://doi.org/10.3934/mbe.2025045","url":null,"abstract":"<p><p>Legionnaires' disease (LD) is a largely understudied and underreported pneumonic environmentally transmitted disease caused by the bacteria Legionella. It primarily occurs in places with poorly maintained artificial sources of water. There is currently a lack of mathematical models on the dynamics of LD. In this paper, we formulate a novel ordinary differential equation-based susceptible-exposed-infected-recovered (SEIR) model for LD. One issue with LD is the difficulty in its detection, as the majority of countries around the world lack the proper surveillance and diagnosis methods. Thus, there is not much publicly available data or literature on LD. We use parameter estimation for our model with one of the few outbreaks with time series data from Murcia, Spain in 2001. Furthermore, we apply a global sensitivity analysis to understand the contributions of parameters to our model output. To consider managing LD outbreaks, we explore implementing sanitizing individual sources of water by constructing an optimal control problem. Using our fitted model and the optimal control problem, we analyze how different parameters and controls might help manage LD outbreaks in the future.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 5","pages":"1226-1242"},"PeriodicalIF":2.6,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144023360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stochastic forest transition model dynamics and parameter estimation via deep learning.","authors":"Satoshi Kumabe, Tianyu Song, Tôn Việt Tạ","doi":"10.3934/mbe.2025046","DOIUrl":"https://doi.org/10.3934/mbe.2025046","url":null,"abstract":"<p><p>Forest transitions, characterized by dynamic shifts between forest, agricultural, and abandoned lands, are complex phenomena. This study developed a stochastic differential equation model to capture the intricate dynamics of these transitions. We established the existence of global positive solutions for the model and conducted numerical analyses to assess the impact of model parameters on deforestation incentives. To address the challenge of parameter estimation, we proposed a novel deep learning approach that estimates all model parameters from a single sample containing time-series observations of forest and agricultural land proportions. This innovative approach enables us to understand forest transition dynamics and deforestation trends at any future time.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 5","pages":"1243-1262"},"PeriodicalIF":2.6,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144049807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yixun Xing, Casey Moore, Debabrata Saha, Dan Nguyen, MaryLena Bleile, Xun Jia, Robert Timmerman, Hao Peng, Steve Jiang
{"title":"Mathematical modeling of the synergetic effect between radiotherapy and immunotherapy.","authors":"Yixun Xing, Casey Moore, Debabrata Saha, Dan Nguyen, MaryLena Bleile, Xun Jia, Robert Timmerman, Hao Peng, Steve Jiang","doi":"10.3934/mbe.2025044","DOIUrl":"https://doi.org/10.3934/mbe.2025044","url":null,"abstract":"<p><p>The synergy between radiotherapy and immunotherapy plays a pivotal role in enhancing tumor control and treatment outcomes. To explore the underlying mechanisms of synergy, we investigated a novel treatment approach known as personalized ultra-fractionated stereotactic adaptive radiation (PULSAR) therapy, which emphasizes the impact of radiation timing. Unlike conventional daily treatments, PULSAR delivers high-dose radiation in spaced intervals over weeks or months, enabling tumors to adapt and potentially enhancing synergy with immunotherapy. Drawing on insights from small-animal radiation studies, we developed a discrete-time model based on multiple difference equations to elucidate the temporal dynamics of tumor control driven by both radiation and the adaptive immune response. By accounting for the migration and infiltration of T cells within the tumor microenvironment, we established a quantitative link between radiation therapy and immunotherapy. Model parameters were estimated using a simulated annealing algorithm applied to training data, and our model achieved high accuracy for the test data with a root mean square error of 287 mm<sup>3</sup>. Notably, our framework replicated the PULSAR effect observed in animal studies, revealing that longer intervals between radiation treatments in the context of immunotherapy yielded enhanced tumor control. Specifically, mice receiving immunotherapy alongside radiation pulses delivered at extended intervals, ten days, showed markedly improved tumor responses, whereas those treated with shorter intervals did not achieve comparable benefits. Moreover, our model offers an in-silico tool for designing future personalized ultra-fractionated stereotactic adaptive radiation trials. Overall, these findings underscore the critical importance of treatment timing in harnessing the synergy between radiotherapy and immunotherapy and highlight the potential of our model to optimize and individualize treatment protocols.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 5","pages":"1206-1225"},"PeriodicalIF":2.6,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144043744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bruno Buonomo, Rossella Della Marca, Manalebish Debalike Asfaw
{"title":"Modelling human response to information in voluntary vaccination behaviour using epidemic data.","authors":"Bruno Buonomo, Rossella Della Marca, Manalebish Debalike Asfaw","doi":"10.3934/mbe.2025043","DOIUrl":"https://doi.org/10.3934/mbe.2025043","url":null,"abstract":"<p><p>Here, we considered Holling functional responses, a core concept in population dynamics, and discussed their potential interpretation in the context of social epidemiology. Then, we assessed which Holling functional response best represents the vaccination behaviour of individuals when such a behaviour is influenced by information and rumours about the disease. In particular, we used the Holling functionals to represent the information-dependent vaccination rate in a socio-epidemiological model for meningococcal meningitis. As a field case test, we estimated the information-related parameters by using official data from a meningitis outbreak in Nigeria and numerically assessed the impact of the functionals on the solutions of the model. We observed significant inaccuracies on parameter estimates when either Holling type Ⅰ or Holling type Ⅲ functional were used. On the contrary, when the Holling type Ⅱ functional was employed, epidemiological data were well reproduced, and reasonable values of the information parameters were obtained. Given the socio-epidemiological interpretation of the Holling type Ⅱ functional, this means that the rate at which susceptible individuals come into contact with information may be assumed to be constant and that the time needed to handle the available information cannot be neglected.</p>","PeriodicalId":49870,"journal":{"name":"Mathematical Biosciences and Engineering","volume":"22 5","pages":"1185-1205"},"PeriodicalIF":2.6,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144040937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}