Mathematical Modelling of Natural Phenomena最新文献

Lévy flights, optimal foraging strategies, and foragers with a finite lifespan 莱维飞行、最佳觅食策略和寿命有限的觅食者

IF 2.6 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-07-03 DOI: 10.1051/mmnp/2024015

S. Dipierro, Giovanni Giacomin, Enrico Valdinoci

引用次数: 0

Patient-specific input data for predictive modeling of the Fontan operation 用于方坦手术预测建模的特定患者输入数据

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-06-12 DOI: 10.1051/mmnp/2024013

T. Dobroserdova, Lyudmila Yurpolskaya, Yuri Vassilevski, Andrey Svobodov

{"title":"Patient-specific input data for predictive modeling of the Fontan operation","authors":"T. Dobroserdova, Lyudmila Yurpolskaya, Yuri Vassilevski, Andrey Svobodov","doi":"10.1051/mmnp/2024013","DOIUrl":"https://doi.org/10.1051/mmnp/2024013","url":null,"abstract":"Personalized blood flow models are used for optimization of the Fontan procedure. In this paper we discuss clinical data for model initialization. Before the Fontan procedure patients undergo CT or MRI examination. Computational domain of interest is reconstructed from this data. CT images are shown to have a better spatial resolution and quality and are more suitable for segmentation. MRI data gives information about blood flow rates and it is utilized for setting boundary conditions in local 3D hemodynamic models.\u0000 \u0000We discovered that the MRI data is contradictory and too inaccurate for setting boundary conditions: the error of measured velocities is comparable with blood velocities in veins. We discuss a multiscale 1D3D circulation model as potentially suitable for prediction of the Fontan procedure results. Such model may be initialized with more reliable data (MR measurements of blood flow in aorta and ultrasound examination of easily accessible vessels) and take into account collateral and fenestration blood flows which are typical for Fontan patients. We have calculated these flow rates for several patients and demonstrated that such flows occur systematically.","PeriodicalId":18285,"journal":{"name":"Mathematical Modelling of Natural Phenomena","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141355312","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}

引用次数: 0

Multi-wave modelling and short-term prediction of ICU bed occupancy by patients with COVID-19 in regions of Italy 意大利各地区 COVID-19 患者重症监护病房床位占用率的多波建模和短期预测

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-05-23 DOI: 10.1051/mmnp/2024012

Frederico José Ribeiro Pelogia, Henrique Mohallem Paiva, Roberson Saraiva Polli

{"title":"Multi-wave modelling and short-term prediction of ICU bed occupancy by patients with COVID-19 in regions of Italy","authors":"Frederico José Ribeiro Pelogia, Henrique Mohallem Paiva, Roberson Saraiva Polli","doi":"10.1051/mmnp/2024012","DOIUrl":"https://doi.org/10.1051/mmnp/2024012","url":null,"abstract":"Contribution: This study provides insights into COVID-19 dynamics by employing a phenomenological model representing multiple epidemiological waves. It aims to support decision-making for health authorities and hospital administrators, particularly in optimizing Intensive Care Unit (ICU) bed management and implementing effective containment measures. Background: Given the intricate complexity of ICU environments, utilizing a mathematical model to anticipate occupancy is highly beneficial and might mitigate mortality rates associated with COVID-19. The study focuses on the evolution of intensive care patient numbers across multiple epidemiological waves in Italian regions. Methodology: Our methodology involves the application of a low-complexity phenomenological model with an efficient optimization procedure. ICU occupancy data from five populous Italian regions are utilized to demonstrate the model’s efficacy on describing historical data and providing forecasts for two-week intervals. Findings: Drawing from the analyzed ICU occupancy data, the study establishes the effectiveness of the proposed model. It successfully fits historical data and offers accurate forecasts, achieving an average relative RMSE of 0.51% for the whole fit and 0.93% for the predictions, across all regions. Beyond the immediate context, the model low complexity and efficient optimization make it suitable to diverse regions and diseases, supporting the tracking and containment of future epidemics.","PeriodicalId":18285,"journal":{"name":"Mathematical Modelling of Natural Phenomena","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141104312","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}

引用次数: 0

Mathematical Modelling of Natural Phenomena 自然现象的数学建模

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-05-22 DOI: 10.1051/mmnp/2024010

A. Decoene, Sebastien Martin, Chabane Meziane

{"title":"Mathematical Modelling of Natural Phenomena","authors":"A. Decoene, Sebastien Martin, Chabane Meziane","doi":"10.1051/mmnp/2024010","DOIUrl":"https://doi.org/10.1051/mmnp/2024010","url":null,"abstract":"We propose a hierarchy of mathematical models for the numerical simulation of active thin structures in a viscous fluid and its application to mucociliary transport. Our aim is to simulate large forests of cilia and analyze the collective dynamics arising in the flow, as well as their impact on the efficiency of the mucus transport. In a 3d model we describe the cilia individually and study their joint actions on the fluid. The model is built upon a 3d Stokes problem with singular source terms that represent the action of the 1d cilia on the fluid, including the background flow (making the problem nonlocal). Surface tension between the periciliary layer and the mucus is taken into account. From the 3d model we also derive a 1d space averaged model, describing the dynamics of the mean velocity of the mucus that is propelled by the cilia, hence allowing lower computational costs and still providing useful characterization of the efficiency of the transport. Mathematical properties of the models (existence and uniqueness of solutions in suitable functional spaces) are analyzed. Numerical simulations highlight the influence of critical parameters on the efficiency of the mucociliary transport in the case of dense forests of cilia.","PeriodicalId":18285,"journal":{"name":"Mathematical Modelling of Natural Phenomena","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141110272","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}

引用次数: 0

Generalities on a delayed spatiotemporal host-pathogen infection model with distinct dispersal rates 具有不同扩散率的延迟时空宿主-病原体感染模型的一般情况

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-05-16 DOI: 10.1051/mmnp/2024008

Djilali salih

引用次数: 0

The role of Allee effect in cannibalistic species: An action plan to sustain the declining cod population 阿利效应在食人物种中的作用：维持鳕鱼数量下降的行动计划

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-05-15 DOI: 10.1051/mmnp/2024007

Parimita Roy, Sanjoli Jain, Mohamed Maama

{"title":"The role of Allee effect in cannibalistic species: An action plan to sustain the declining cod population","authors":"Parimita Roy, Sanjoli Jain, Mohamed Maama","doi":"10.1051/mmnp/2024007","DOIUrl":"https://doi.org/10.1051/mmnp/2024007","url":null,"abstract":"Atlantic cod collapsed in the late 20th century after being harvested heavily for 50 years. This paper aims to design conservation guidelines for the cod population, which is diminishing due to predation by grey seals and cannibalism. For this purpose, we first designed a continuous time ecological model (with and without the Allee effect) using a system of differential equations consisting of juvenile Atlantic cod, adult Atlantic cod, and grey seals. The developed model has set forth global existence, non-negativity, and long-term behavior. Subsequently, to handle the extinction problem cost-effectively, Pontryagin's principle is employed to construct the optimal control, which is then numerically solved using an iterative forward–backward method. We numerically explored the impact of the Allee effect on cod survival within the original model and its two extended versions (i) stochastic and (ii) reaction-diffusion, to thoroughly understand the possible consequences wherein a population has cannibalistic tendencies. The numerical comparison between the non-Allee and Allee models (Ordinary, Stochastic, Reaction-Diffusion) reveals that the Allee effect may significantly promote recovery and benefit the cannibalistic population. We adopted a partial rank correlation coefficient (PRCC) to conduct a global sensitivity analysis to estimate the most sensitive parameters responsible for cod prevalence.","PeriodicalId":18285,"journal":{"name":"Mathematical Modelling of Natural Phenomena","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140974365","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}

引用次数: 0

Additive multiple contacts and saturation phenomena in epidemiological models are not detected by $R_0$ R_0$ 检测不到流行病学模型中的加性多重接触和饱和现象

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-04-01 DOI: 10.1051/mmnp/2024006

José Geiser Villavicencio-Pulido, I. Barradas, C. Nila-Luévano

{"title":"Additive multiple contacts and saturation phenomena in epidemiological models are not detected by $R_0$","authors":"José Geiser Villavicencio-Pulido, I. Barradas, C. Nila-Luévano","doi":"10.1051/mmnp/2024006","DOIUrl":"https://doi.org/10.1051/mmnp/2024006","url":null,"abstract":"Many infections are transmitted by direct contacts. Usually one single direct contact is needed to transmit the required minimum infectious load. Most models describe contagions by single contacts using a term of the type mass action law. However, modelling infections that are transmitted after the susceptible individual had contact with several sources of infection requires more than mass action law terms. We call additive multiple contacts those that do not produce infection by themselves, but can produce infection if they happen simultaneously. We are interested in understanding the role played by R0 missing the mark in infections in which the minimum infectious load is reached not only by single contacts but also by additive multiple contacts. We propose different mathematical models describing not only infections by one single contact but also by additive multiple contacts. We show all models have the same value of R0, but correspond to different epidemiological mechanisms. Two models show contagions by additive multiple contacts and a third one shows reduction of infections by some saturation process which is not captured by R0. This shows that trying to control the epidemics by controlling R0 could be unsufficient or in some cases waste resources.","PeriodicalId":18285,"journal":{"name":"Mathematical Modelling of Natural Phenomena","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140353088","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}

引用次数: 0

(3+1)-dimensional Gardner equation deformed from (1+1)-dimensional Gardner equation and its conservation law 由 (1+1) 维加德纳方程变形而来的 (3+1) 维加德纳方程及其守恒定律

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-03-11 DOI: 10.1051/mmnp/2024004

Guiming Jin, Xueping Cheng, Jianan Wang

引用次数: 0

Global Hopf bifurcation of a delayed diffusive Gause-type predator-prey system with the fear effect and Holling type III functional response 具有恐惧效应和霍林 III 型功能响应的延迟扩散高斯型捕食者-猎物系统的全局霍普夫分岔

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-02-16 DOI: 10.1051/mmnp/2024003

Qian Zhang, Ming Liu, Xiaofeng Xu

引用次数: 0

Global Hopf bifurcation of a delayed diffusive Gause-type predator-prey system with the fear effect and Holling type III functional response 具有恐惧效应和霍林 III 型功能响应的延迟扩散高斯型捕食者-猎物系统的全局霍普夫分岔

IF 2.2 4区数学

Mathematical Modelling of Natural Phenomena Pub Date : 2024-02-16 DOI: 10.1051/mmnp/2024003

Qian Zhang, Ming Liu, Xiaofeng Xu

引用次数: 0