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

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

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 : 2025-03-27 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":"https://doi.org/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°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":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-27","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

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

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

Forecasting the changes between endemic and epidemic phases of a contagious disease, with the example of COVID-19. 以 COVID-19 为例，预测传染病在流行期和流行期之间的变化。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqae012

Jacques Demongeot, Pierre Magal, Kayode Oshinubi

{"title":"Forecasting the changes between endemic and epidemic phases of a contagious disease, with the example of COVID-19.","authors":"Jacques Demongeot, Pierre Magal, Kayode Oshinubi","doi":"10.1093/imammb/dqae012","DOIUrl":"10.1093/imammb/dqae012","url":null,"abstract":"Background: Predicting the endemic/epidemic transition during the temporal evolution of a contagious disease.Methods: Indicators for detecting the transition endemic/epidemic, with four scalars to be compared, are calculated from the daily reported news cases: coefficient of variation, skewness, kurtosis and entropy. The indicators selected are related to the shape of the empirical distribution of the new cases observed over 14 days. This duration has been chosen to smooth out the effect of weekends when fewer new cases are registered. For finding a forecasting variable, we have used the principal component analysis (PCA), whose first principal component (a linear combination of the selected indicators) explains a large part of the observed variance and can then be used as a predictor of the phenomenon studied (here the occurrence of an epidemic wave).Results: A score has been built from the four proposed indicators using the PCA, which allows an acceptable level of forecasting performance by giving a realistic retro-predicted date for the rupture of the stationary endemic model corresponding to the entrance in the epidemic exponential growth phase. This score is applied to the retro-prediction of the limits of the different phases of the COVID-19 outbreak in successive endemic/epidemic transitions for three countries, France, India and Japan.Conclusion: We provided a new forecasting method for predicting an epidemic wave occurring after an endemic phase for a contagious disease.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"98-112"},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142010169","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

Biological invasions and epidemics with nonlocal diffusion along a line. 沿线非局部扩散的生物入侵和流行病。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2025-03-17 DOI: 10.1093/imammb/dqae014

Henri Berestycki, Jean-Michel Roquejoffre, Luca Rossi

{"title":"Biological invasions and epidemics with nonlocal diffusion along a line.","authors":"Henri Berestycki, Jean-Michel Roquejoffre, Luca Rossi","doi":"10.1093/imammb/dqae014","DOIUrl":"10.1093/imammb/dqae014","url":null,"abstract":"To James D. Murray, with our admiration. The goal of this work is to understand and quantify how a line with nonlocal diffusion given by an integral enhances a reaction-diffusion process occurring in the surrounding plane. This is part of a long-term programme where we aim at modelling, in a mathematically rigorous way, the effect of transportation networks on the speed of biological invasions or propagation of epidemics. We prove the existence of a global propagation speed and characterize in terms of the parameters of the system the situations where such a speed is boosted by the presence of the line. In the course of the study we also uncover unexpected regularity properties of the model. On the quantitative side, the two main parameters are the intensity of the diffusion kernel and the characteristic size of its support. One outcome of this work is that the propagation speed will significantly be enhanced even if only one of the two is large, thus broadening the picture that we have already drawn in our previous works on the subject, with local diffusion modelled by a standard Laplacian. We further investigate the role of the other parameters, enlightening some subtle effects due to the interplay between the diffusion in the half plane and that on the line. Lastly, in the context of propagation of epidemics, we also discuss the model where, instead of a diffusion, displacement on the line comes from a pure transport term.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"4-37"},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141891446","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 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 : 2025-03-13 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":"https://doi.org/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 simply by diffusion but also 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; that is, 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":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-13","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

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 : 2025-02-12 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":"https://doi.org/10.1093/imammb/dqaf001","url":null,"abstract":"Controlling the elevated levels of methane (CH4) 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":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-12","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

Effect of diffusivity of amyloid beta monomers on the formation of senile plaques. 淀粉样 beta 单体的扩散性对老年斑形成的影响

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-12-16 DOI: 10.1093/imammb/dqae019

Andrey V Kuznetsov

{"title":"Effect of diffusivity of amyloid beta monomers on the formation of senile plaques.","authors":"Andrey V Kuznetsov","doi":"10.1093/imammb/dqae019","DOIUrl":"10.1093/imammb/dqae019","url":null,"abstract":"Alzheimer's disease (AD) presents a perplexing question: why does its development span decades, even though individual amyloid beta (Aβ) deposits (senile plaques) can form rapidly in as little as 24 hours, as recent publications suggest? This study investigated whether the formation of senile plaques can be limited by factors other than polymerization kinetics alone. Instead, their formation may be limited by the diffusion-driven supply of Aβ monomers, along with the rate at which the monomers are produced from amyloid precursor protein and the rate at which Aβ monomers undergo degradation. A mathematical model incorporating the nucleation and autocatalytic process (via the Finke-Watzky model), as well as Aβ monomer diffusion, was proposed. The obtained system of partial differential equations was solved numerically, and a simplified version was investigated analytically. The computational results predicted that it takes approximately 7 years for Aβ aggregates to reach a neurotoxic concentration of 50 μM. Additionally, a sensitivity analysis was performed to examine how the diffusivity of Aβ monomers and their production rate impact the concentration of Aβ aggregates.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"346-362"},"PeriodicalIF":0.0,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484531","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