Mathematical Biosciences最新文献

{"title":"Stretch-induced recruitment of myosin into transversal actin rings stabilises axonal large cargo transport","authors":"Nizhum Rahman ,&nbsp;Dietmar B. Oelz","doi":"10.1016/j.mbs.2025.109400","DOIUrl":"10.1016/j.mbs.2025.109400","url":null,"abstract":"<div><div>We study the axonal transport of large cargo vesicles and its feedback with contractile transversal actomyosin rings in axons through modelling and simulation. To this end, we simulate a mathematical model that integrates forces generated by the molecular motors and forces exerted by transversal actin rings. Our results predict that cargo vesicles exhibit bidirectional movement along with pauses in agreement with observations. It has been observed that during predominantly retrograde axonal cargo transport, blebbistatin treatment prolongs the periods spent by the cargo in anterograde transport. Our simulations show that this can be explained by mechanotransductive stretch-induced recruitment of myosin motors into transversal actin rings. These findings offer valuable insights into the complex dynamics of axonal cargo transport and propose potential avenues for further experimental research.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"381 ","pages":"Article 109400"},"PeriodicalIF":1.9,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid analysis with phylogeny and population modeling to estimate the recent founding date of a population: A case study in the origins of COVID-19 illustrates how a branching process approximation can simplify a hybrid analysis","authors":"John L. Spouge","doi":"10.1016/j.mbs.2025.109401","DOIUrl":"10.1016/j.mbs.2025.109401","url":null,"abstract":"<div><div>The exact date of the primary infection in COVID-19 remains unknown. One influential article (Pekar et al. (2021)) estimated the date with a hybrid analysis combining epidemiological and phylogenetic methods. The phylogenetic methods analyzed 583 SARS-COV-2 complete genomes to estimate the sample tMRCA (time of the most recent common ancestor). Before igniting as an epidemic, however, COVID-19 may have had several population bottlenecks with only a single infected person, so the MRCA merely represents the last such bottleneck. Pekar et al. (2021) therefore used epidemiological methods to estimate the time from the primary infection to the sample MRCA. The hybrid method involved several arbitrary decisions, however, reflecting the fact that the epidemiological and phylogenetic analyses overlap at the sample MRCA and are generally probabilistically dependent. Towards removing the dependence, note that the start of an epidemic has a branching process approximation. Let the branching process have a single ancestor. If the branching process does not go extinct, define skeleton particles (individuals) to be particles whose lineages do not go extinct, and define the long-time MRCA as the earliest skeleton particle with at least two skeleton offspring. A linear phylogeny of skeleton particles therefore separates the ancestor from the long-time MRCA. Probabilistically, the linear phylogeny is a defective renewal process of skeleton particles, making the generation count geometrically distributed. Moreover, the terminology “long-time MRCA” is apt, because as time becomes arbitrarily large, the MRCA of the corresponding extant population approaches the long-time MRCA. Effectively, the focus on the long-time MRCA makes the forward epidemiological and backward phylogenetic analyses probabilistically independent. The present article can therefore confirm most of the epidemiological conclusions of the hybrid analysis of Pekar et al. (2021). Its use of branching process approximations also points the way to noticeable simplifications in the hybrid method.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"382 ","pages":"Article 109401"},"PeriodicalIF":1.9,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143416645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A conceptual framework for modeling a latching mechanism for cell cycle regulation","authors":"Punit Gandhi ,&nbsp;Yangyang Wang","doi":"10.1016/j.mbs.2025.109396","DOIUrl":"10.1016/j.mbs.2025.109396","url":null,"abstract":"<div><div>Two identical van der Pol oscillators with mutual inhibition are considered as a conceptual framework for modeling a latching mechanism for cell cycle regulation. In particular, the oscillators are biased to a latched state in which there is a globally attracting steady-state equilibrium without coupling. The inhibitory coupling induces stable alternating large-amplitude oscillations that model the normal cell cycle. A homoclinic bifurcation within the model is found to be responsible for the transition from normal cell cycling to endocycles in which only one of the two oscillators undergoes large-amplitude oscillations.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"382 ","pages":"Article 109396"},"PeriodicalIF":1.9,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143411670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equilibrium analysis of discrete stochastic population models with gamma distribution","authors":"Haiyan Wang","doi":"10.1016/j.mbs.2025.109398","DOIUrl":"10.1016/j.mbs.2025.109398","url":null,"abstract":"<div><div>This paper analyzes the stochastic logistic and Ricker difference equations at equilibrium with the gamma distribution. We identify mathematical relationships among the intrinsic growth rate in the stochastic equations, the parameters of the gamma distribution and a small stochastic perturbation. The mathematical relations reveal that there are two branches of the intrinsic growth rate, representing alternative stable states corresponding to higher and lower growth rates. This duality provides deeper insights into population stability and resilience under stochastic conditions. We present the biological significance of these relationships, emphasizing how the stochastic perturbation and shape parameter of the gamma distribution influence population dynamics at equilibrium.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"381 ","pages":"Article 109398"},"PeriodicalIF":1.9,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of phase tumbling and the reentrainment of circadian oscillators","authors":"Guangyuan Liao ,&nbsp;Casey O. Diekman ,&nbsp;Amitabha Bose","doi":"10.1016/j.mbs.2025.109381","DOIUrl":"10.1016/j.mbs.2025.109381","url":null,"abstract":"<div><div>Circadian clocks are comprised of networks of cellular oscillators that synchronize to produce endogenous daily rhythms in gene expression and protein abundance. These clocks have evolved to align the physiology and behavior of organisms to the 24-h environmental cycles arising from Earth’s rotation. Rapid travel across time zones causes misalignment between an organism’s circadian rhythms and its environment, leading to sleep problems and other jet lag symptoms until the circadian system entrains to the external cycles of the new time zone. Experimental and modeling work has shown that phase tumbling, defined as desynchronizing networks of circadian oscillators prior to an abrupt phase shift of the light-dark cycle, can speed up the process of reentrainment. Here, we use a mathematical model of circadian oscillators and 2-D entrainment maps to analyze the conditions under which phase tumbling has a positive, neutral, or negative effect on reentrainment time. We find that whether or not phase tumbling is beneficial depends on the size of the external phase shift and the location of the perturbed oscillator with respect to the fixed points and invariant manifolds of the entrainment map.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"381 ","pages":"Article 109381"},"PeriodicalIF":1.9,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal control of species augmentation in a competition model","authors":"Munkaila Dasumani ,&nbsp;Suzanne Lenhart ,&nbsp;Gladys K. Onyambu ,&nbsp;Stephen E. Moore","doi":"10.1016/j.mbs.2025.109394","DOIUrl":"10.1016/j.mbs.2025.109394","url":null,"abstract":"<div><div>Mathematical models of endangered competitive interactions incorporating the Allee effect with augmentation strategies have not been studied extensively. This area is however critical to ecologists since it relates to ways species can become endangered and possibly go extinct due to competition for limited resources. More importantly, the climatic change with its adverse effects has not only affected green forests but has also caused the extinction of some species. Thus, there is a need for critical augmentation strategies to safeguard such species. This paper, therefore, presents an optimal control strategy for a continuous time competition interaction model with strong Allee effects. We seek to maximize the target species at the end of each final time. We consider two objective functionals involving the populations and the cost of the controls. Using Pontryagin’s Maximum Principle, we obtain the optimal control characterizations. We perform numerical simulations using the forward–backward sweep method and the approximate solutions are presented and discussed. Since there is a cost involved in the translocation of the reserve species, we adopt a minimization cost strategy. In addition, we compute the objective functional values for each simulation.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"381 ","pages":"Article 109394"},"PeriodicalIF":1.9,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling the influence of the objective functional on epidemic optimal control: Insights from the SIR model","authors":"Fernando Saldaña ,&nbsp;Hao Wang ,&nbsp;José Ariel Camacho-Gutiérrez","doi":"10.1016/j.mbs.2025.109395","DOIUrl":"10.1016/j.mbs.2025.109395","url":null,"abstract":"<div><div>In the application of optimal control theory to medical and biological problems, the dependence of the objective functional on the control variable is often subject to uncertainty. This study examines the effects of this dependency on the outcomes of optimal control problems in the context of disease control using the SIR model. We formulate two distinct optimal control problems: one for the control of disease spread through prophylactic vaccination, and another for the treatment of infected individuals. For each scenario, we propose four variations of the objective functional to capture the cost of control interventions, namely, quadratic state-independent, quadratic state-dependent, linear state-independent, and linear state-dependent. We also conduct numerical simulations to compare optimal control solutions across different weight parameters. While some qualitative characteristics of the control profiles are similar in certain scenarios, there are also notable differences suggesting that the choice of objective functional can substantially alter the resulting control profiles. Consequently, when there is uncertainty regarding the functional form of the objective and its relationship to the control parameter, it is recommended to evaluate multiple objectives and subsequently identify which solution is most suitable for practical implementation.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"381 ","pages":"Article 109395"},"PeriodicalIF":1.9,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Target reproduction numbers for time-delayed population systems","authors":"Xueying Wang ,&nbsp;Xiao-Qiang Zhao","doi":"10.1016/j.mbs.2025.109384","DOIUrl":"10.1016/j.mbs.2025.109384","url":null,"abstract":"<div><div>In the field of population dynamics, target reproduction number is a crucial metric that dictates the necessary control efforts for achieving specific prevention, intervention, or control goals. Recently, the concept of the target reproduction number has undergone significant extensions. Lewis et al. <span><span>[1]</span></span> presented a general framework of the target reproduction number for nonnegative matrices, and Wang and Zhao <span><span>[2]</span></span> further developed it to positive operators on an ordered Banach space. These extensions encompass fundamental metrics like basic reproduction number and type reproduction number, along with other threshold parameters from existing literature, elucidating their roles in population control. In the current paper, we establish the theory of target reproduction number for a large class of compartmental population models with time delay in the case where control is targeted toward either new infection/production or internal evolution/transition. It turns out that the target reproduction number of the original time-delayed population model can be viewed as a basic reproduction number of some modified system. At the end, we apply these analytic results to three epidemic models, which enhances our theoretical understanding and provides valuable insights for effective strategies in population-based interventions and control measures.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"381 ","pages":"Article 109384"},"PeriodicalIF":1.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143344367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergence of multiple foraging strategies under competition","authors":"Hyunjoong Kim ,&nbsp;Manoj Subedi ,&nbsp;Krešimir Josić","doi":"10.1016/j.mbs.2025.109377","DOIUrl":"10.1016/j.mbs.2025.109377","url":null,"abstract":"<div><div>Foraging strategies are shaped by interactions with the environment, and evolve under metabolic constraints. Optimal strategies for isolated and competing organisms have been studied extensively in the absence of evolution. Much less is understood about how metabolic constraints shape the evolution of an organism’s ability to detect and reach food. To address this question, we introduce a minimal agent-based model of the coevolution of two phenotypic attributes critical for successful foraging in crowded environments: movement speed and perceptual acuity. Under competition higher speed and acuity lead to better foraging success, but at higher metabolic cost. We derive the optimal foraging strategy for a single agent, and show that this strategy is no longer optimal for foragers in a group. We show that mutation and selection can lead to the coexistence of two strategies: A metabolically costly strategy with high acuity and velocity, and a metabolically cheap strategy. Generally, in evolving populations speed and acuity co-vary. Therefore, even under metabolic constraints, trade-offs between metabolically expensive traits are not guaranteed.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"380 ","pages":"Article 109377"},"PeriodicalIF":1.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling the role of temperature-dependent microbiome composition in black band disease transmission among coral reefs","authors":"Alex Busalacchi ,&nbsp;Maya Weissman ,&nbsp;Feng-Bin Wang ,&nbsp;Naveen K. Vaidya","doi":"10.1016/j.mbs.2024.109371","DOIUrl":"10.1016/j.mbs.2024.109371","url":null,"abstract":"<div><div>Black band disease (BBD) is one of the most prevalent diseases causing significant destruction of coral reefs. Coral reefs acquire this deadly disease from bacteria in the microbiome community, the composition of which is highly affected by the environmental temperature. While previous studies have provided valuable insights into various aspects of BBD, the temperature-dependent microbiome composition has not been considered in existing BBD models. We developed a transmission dynamics model, incorporating the effects of temperature on the microbiome composition and, subsequently, on BBD in coral reefs. Based on our non-autonomous model systems, we calculate the infection invasion threshold, providing an environmental condition for the disease to persist in the coral reef community. Our results suggest that temperature significantly impacts coral reef health, with microbiome-favored moderate environmental temperatures resulting in more BBD-infected corals. Our model and related results help investigate potential strategies to protect reef ecosystems from stressors, including BBD.</div></div>","PeriodicalId":51119,"journal":{"name":"Mathematical Biosciences","volume":"380 ","pages":"Article 109371"},"PeriodicalIF":1.9,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}