Mathematical medicine and biology : a journal of the IMA最新文献

Estimating transmission parameters and the reproduction number: COVID-19 in Sri Lanka as a case study. 估计传播参数和繁殖数量：以斯里兰卡COVID-19为例研究。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-05-30 DOI: 10.1093/imammb/dqaf005

Dinesh B Ekanayake, Iduruwage Harsha Premarathna, Elizabeth Hansen

{"title":"Estimating transmission parameters and the reproduction number: COVID-19 in Sri Lanka as a case study.","authors":"Dinesh B Ekanayake, Iduruwage Harsha Premarathna, Elizabeth Hansen","doi":"10.1093/imammb/dqaf005","DOIUrl":"https://doi.org/10.1093/imammb/dqaf005","url":null,"abstract":"The study of the dynamics of an infectious disease is fundamental to understanding its community spread. These include obtaining estimates for transmission rates, recovery rates, and the average number of secondary cases per infectious case (reproduction number). Social behaviors, control measures, environmental conditions, and long recovery times result in time varying parameters. Further, imperfect data and many uncertainties lead to inaccurate estimations. This is particularly true in third-world countries, where a greater proportion of people with mild infections may not seek medical treatment. Data on the prevalence of COVID-19 provides an excellent source for case studies to analyze time-dependent parameters. Using Sri Lankan COVID-19 data, we demonstrate how one could utilize Itˆo stochastic differential equations with a gamma distribution correction to estimate disease transmission parameters as a function of time. As we illustrated here, the model is well-suited for forecasting the dates of peak prevalence and the number of new cases using the estimated parameters.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144188738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Mathematical Model of Clonal Hematopoiesis Explaining Phase Transitions in Chronic Myeloid Leukemia. 克隆造血的数学模型解释慢性髓系白血病的相变。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-05-07 DOI: 10.1093/imammb/dqaf004

Lorand Gabriel Parajdi, Xue Bai, Dávid Kegyes, Ciprian Tomuleasa

引用次数: 0

A network-level transport model of tau progression in the Alzheimer's brain. 阿尔茨海默病大脑中tau蛋白进展的网络水平转运模型。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqaf003

Veronica Tora, Justin Torok, Michiel Bertsch, Ashish Raj

{"title":"A network-level transport model of tau progression in the Alzheimer's brain.","authors":"Veronica Tora, Justin Torok, Michiel Bertsch, Ashish Raj","doi":"10.1093/imammb/dqaf003","DOIUrl":"10.1093/imammb/dqaf003","url":null,"abstract":"One of the hallmarks of Alzheimer's disease (AD) is the accumulation and spread of toxic aggregates of tau protein. The progression of AD tau pathology is thought to be highly stereotyped, which is in part due to the fact that tau can spread between regions via the white matter tracts that connect them. Mathematically, this phenomenon has been described using models of 'network diffusion,' where the rate of spread of tau between brain regions is proportional to its concentration gradient and the amount of white matter between them. Although these models can robustly predict the progression of pathology in a wide variety of neurodegenerative diseases, including AD, an underexplored aspect of tau spreading is that it is governed not only by diffusion but also by active transport along axonal microtubules. Spread can therefore take on a directional bias, resulting in distinct patterns of deposition, but current models struggle to capture this phenomenon. Recently, we have developed a mathematical model of the axonal transport of toxic tau proteins that takes into account the effects tau exerts on the molecular motors. Here we describe and implement a macroscopic version of this model, which we call the Network Transport Model (NTM). A key feature of this model is that, while it predicts tau dynamics at a regional level, it is parameterized in terms of only microscopic processes such as aggregation and transport rates, i.e., differences in brain-wide tau progression can be explained by its microscopic properties. We provide numerical evidence that, as with the two-neuron model that the NTM extends, there are distinct and rich dynamics with respect to the overall rate of spread and the staging of pathology when we simulated the NTM on the hippocampal subnetwork. The theoretical insights provided by the NTM have broad implications for understanding AD pathophysiology more generally.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"212-238"},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A signal-processing tool adapted to the periodic biphasic phenomena: the Dynalet transform. 适应周期性双相现象的信号处理工具：动态变换。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqae025

Jacques Demongeot, Jean-Gabriel Minonzio

引用次数: 0

Correction to: Inference on an interacting diffusion system with application to in vitro glioblastoma migration (publication template). 更正：关于相互作用扩散系统在胶质母细胞瘤体外迁移中的应用的推论（出版物模板）。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqae023

引用次数: 0

Effects of reduced temperature on oxygen transport from capillaries to brain tissue. 降低温度对氧气从毛细血管输送到脑组织的影响。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqaf002

Samikshaa Natarajan, Timothy W Secomb

{"title":"Effects of reduced temperature on oxygen transport from capillaries to brain tissue.","authors":"Samikshaa Natarajan, Timothy W Secomb","doi":"10.1093/imammb/dqaf002","DOIUrl":"10.1093/imammb/dqaf002","url":null,"abstract":"The normal function of the brain depends on adequate oxygen supply. Oxygen deprivation (hypoxia) can result in irreversible damage to neurons within minutes. Cooling (hypothermia) of brain tissue can reduce the rate of damage, and is used in surgeries where blood flow to the brain is interrupted, such as aortic arch reconstruction. Hypothermia affects several factors that influence tissue oxygen levels, including oxygen consumption rate, diffusivity and solubility. The goal of the present work is to predict the effects of hypothermia on the partial pressure of oxygen in brain tissue. The dependence on temperature of parameters governing oxygen transport is estimated from literature data. A theoretical model based on the Krogh cylinder configuration is used to predict the effects of hypothermia on the distribution of oxygen partial pressure in the cylindrical tissue region surrounding a capillary. For a given blood flow rate and inflowing oxygen level, tissue oxygen levels are shown to increase with decreasing temperature. Although oxygen diffusivity in tissue declines with hypothermia, the reduction in oxygen consumption leads to a net increase in predicted oxygen levels. Tissue hypoxia resulting from reductions in blood flow rate can be ameliorated by reductions in temperature. For example, if blood flow is reduced to 36% of normal, temperature reduction by $2.3^circ{C}$ can increase tissue oxygen levels above the hypoxic range. The results support the use of hypothermia to reduce brain damage under conditions of reduced blood flow.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"239-251"},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143733663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the large time behaviour of the solutions of an evolutionary-epidemic system with spatial dispersal. 关于具有空间分散性的进化-流行系统解的大时间行为。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqae022

A Ducrot, D Manceau, A Sylla

引用次数: 0

KPP transition fronts in a one-dimensional two-patch habitat. 一维双斑块生境中的 KPP 过渡前沿。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqae011

François Hamel, Mingmin Zhang

引用次数: 0

HeMiTo-dynamics: a characterization of mammalian prion toxicity using non-dimensionalization, linear stability and perturbation analyses. 半微动力学：哺乳动物朊病毒毒性的特征使用无量纲化，线性稳定性和摄动分析。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqae024

Johannes G Borgqvist, Christoffer Gretarsson Alexandersen

{"title":"HeMiTo-dynamics: a characterization of mammalian prion toxicity using non-dimensionalization, linear stability and perturbation analyses.","authors":"Johannes G Borgqvist, Christoffer Gretarsson Alexandersen","doi":"10.1093/imammb/dqae024","DOIUrl":"10.1093/imammb/dqae024","url":null,"abstract":"Prion-like proteins play crucial parts in biological processes in organisms ranging from yeast to humans. For instance, many neurodegenerative diseases are believed to be caused by the production of prion-like proteins in neural tissue. As such, understanding the dynamics of prion-like protein production is a vital step toward treating neurodegenerative disease. Mathematical models of prion-like protein dynamics show great promise as a tool for predicting disease trajectories and devising better treatment strategies for prion-related diseases. Herein, we investigate a generic model for prion-like dynamics consisting of a class of non-linear ordinary differential equations (ODEs), establishing constraints through a linear stability analysis that enforce the expected properties of mammalian prion-like toxicity. Furthermore, we identify that prion toxicity evolves through three distinct phases for which we provide analytical descriptions using perturbation analyses. Specifically, prion-toxicity is initially characterized by the healthy phase, where the dynamics are dominated by the healthy form of prions, thereafter the system enters the mixed phase, where both healthy and toxic prions interact, and lastly, the system enters the toxic phase, where toxic prions dominate, and we refer to these phases as HeMiTo-dynamics. These findings hold the potential to aid researchers in developing precise mathematical models for prion-like dynamics, enabling them to better understand underlying mechanisms and devise effective treatments for prion-related diseases.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"159-175"},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142752730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mathematical modeling and analysis of emission and mitigation of methane from the integrated rice-livestock farming system. 水稻-牲畜综合养殖系统甲烷排放与减排的数学建模与分析。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqaf001

Maitri Verma, Alok Kumar Verma

{"title":"Mathematical modeling and analysis of emission and mitigation of methane from the integrated rice-livestock farming system.","authors":"Maitri Verma, Alok Kumar Verma","doi":"10.1093/imammb/dqaf001","DOIUrl":"10.1093/imammb/dqaf001","url":null,"abstract":"Controlling the elevated levels of methane ($mathrm{CH}_{4}$) in the atmosphere is crucial to tackling the problem of climate change. Both rice paddies and livestock farming are substantial contributors to this elevated methane. The integrated rice-livestock farming system is an agricultural practice designed to optimize the use of agricultural waste, while concurrently boosting rice and livestock productivity. Achieving the dual objectives of food security and mitigating climate change demands formulation and implementation of strategies that are aimed at managing the methane emissions from the rice-livestock farming system. This study introduces a nonlinear mathematical model of the emission and mitigation of methane in the integrated rice-livestock farming system. Through qualitative analysis, the model's dynamic behavior is thoroughly explored, identifying conditions for reduction and stabilization of atmospheric methane concentrations. Model parameters are estimated using secondary data on atmospheric methane concentration, rice yield and livestock population. A sensitivity analysis is presented to evaluate the influence of variations in crucial parameters on the system's behavior. Numerical simulations are conducted to confirm the validity of the theoretical results.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"176-211"},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143400941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0