Mathematical medicine and biology : a journal of the IMA最新文献_第3页

Assessing marginal effects of non-pharmaceutical interventions on the transmission of SARS-CoV-2 across Africa: a hybrid modeling study. 评估非药物干预对 SARS-CoV-2 跨非洲传播的边际效应：混合模型研究

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-09-16 DOI: 10.1093/imammb/dqae013

Yvette Montcho, Sidoine Dako, Valère Kolawole Salako, Chénangnon Frédéric Tovissodé, Martin Wolkewitz, Romain Glèlè Kakaï

{"title":"Assessing marginal effects of non-pharmaceutical interventions on the transmission of SARS-CoV-2 across Africa: a hybrid modeling study.","authors":"Yvette Montcho, Sidoine Dako, Valère Kolawole Salako, Chénangnon Frédéric Tovissodé, Martin Wolkewitz, Romain Glèlè Kakaï","doi":"10.1093/imammb/dqae013","DOIUrl":"10.1093/imammb/dqae013","url":null,"abstract":"Since 2019, a new strain of coronavirus has challenged global health systems. Due its fragile healthcare systems, Africa was predicted to be the most affected continent. However, past experiences of African countries with epidemics and other factors, including actions taken by governments, have contributed to reducing the spread of SARS-CoV-2. This study aims to assess the marginal impact of non-pharmaceutical interventions in fifteen African countries during the pre-vaccination period. To describe the transmission dynamics and control of SARS-CoV-2 spread, an extended time-dependent SEIR model was used. The transmission rate of each infectious stage was obtained using a logistic model with NPI intensity as a covariate. The results revealed that the effects of NPIs varied between countries. Overall, restrictive measures related to assembly had, in most countries, the largest reducing effects on the pre-symptomatic and mild transmission, while the transmission by severe individuals is influenced by privacy measures (more than $10%$). Countries should develop efficient alternatives to assembly restrictions to preserve the economic sector. This involves e.g. training in digital tools and strengthening digital infrastructures.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"225-249"},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141857499","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 modelling, selection and hierarchical inference to determine the minimal dose in IFNα therapy against myeloproliferative neoplasms. 通过数学建模、选择和层次推理，确定 IFNα 治疗骨髓增殖性肿瘤的最小剂量。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-06-15 DOI: 10.1093/imammb/dqae006

Gurvan Hermange, William Vainchenker, Isabelle Plo, Paul-Henry Cournède

引用次数: 0

Phenotype divergence and cooperation in isogenic multicellularity and in cancer. 同源多细胞和癌症中的表型分化与合作

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-06-15 DOI: 10.1093/imammb/dqae005

Frank Ernesto Alvarez, Jean Clairambault

{"title":"Phenotype divergence and cooperation in isogenic multicellularity and in cancer.","authors":"Frank Ernesto Alvarez, Jean Clairambault","doi":"10.1093/imammb/dqae005","DOIUrl":"10.1093/imammb/dqae005","url":null,"abstract":"We discuss the mathematical modelling of two of the main mechanisms that pushed forward the emergence of multicellularity: phenotype divergence in cell differentiation and between-cell cooperation. In line with the atavistic theory of cancer, this disease being specific of multicellular animals, we set special emphasis on how both mechanisms appear to be reversed, however not totally impaired, rather hijacked, in tumour cell populations. Two settings are considered: the completely innovating, tinkering, situation of the emergence of multicellularity in the evolution of species, which we assume to be constrained by external pressure on the cell populations, and the completely planned-in the body plan-situation of the physiological construction of a developing multicellular animal from the zygote, or of bet hedging in tumours, assumed to be of clonal formation, although the body plan is largely-but not completely-lost in its constituting cells. We show how cancer impacts these two settings and we sketch mathematical models for them. We present here our contribution to the question at stake with a background from biology, from mathematics and from philosophy of science.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"135-155"},"PeriodicalIF":0.0,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141545723","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 Model of Individual BMI Trajectories. 个人体重指数轨迹模型。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-03-15 DOI: 10.1093/imammb/dqad009

Laurens Bogaardt, Anoukh van Giessen, H Susan J Picavet, Hendriek C Boshuizen

引用次数: 0

Asymptotic properties of the Lotka-Volterra competition and mutualism model under stochastic perturbations. 随机扰动下 Lotka-Volterra 竞争与互惠模型的渐近特性

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-03-15 DOI: 10.1093/imammb/dqae001

Leonid Shaikhet, Andrei Korobeinikov

{"title":"Asymptotic properties of the Lotka-Volterra competition and mutualism model under stochastic perturbations.","authors":"Leonid Shaikhet, Andrei Korobeinikov","doi":"10.1093/imammb/dqae001","DOIUrl":"10.1093/imammb/dqae001","url":null,"abstract":"Stochastically perturbed models, where the white noise type stochastic perturbations are proportional to the current system state, the most realistically describe real-life biosystems. However, such models essentially have no equilibrium states apart from one at the origin. This feature makes analysis of such models extremely difficult. Probably, the best result that can be found for such models is finding of accurate estimations of a region in the model phase space that serves as an attractor for model trajectories. In this paper, we consider a classical stochastically perturbed Lotka-Volterra model of competing or symbiotic populations, where the white noise type perturbations are proportional to the current system state. Using the direct Lyapunov method in a combination with a recently developed technique, we establish global asymptotic properties of this model. In order to do this, we, firstly, construct a Lyapunov function that is applicable to the both competing (and globally stable) and symbiotic deterministic Lotka-Volterra models. Then, applying this Lyapunov function to the stochastically perturbed model, we show that solutions with positive initial conditions converge to a certain compact region in the model phase space and oscillate around this region thereafter. The direct Lyapunov method allows to find estimates for this region. We also show that if the magnitude of the noise exceeds a certain critical level, then some or all species extinct via process of the stochastic stabilization ('stabilization by noise'). The approach applied in this paper allows to obtain necessary conditions for the extinction. Sufficient conditions for the extinction (that for this model occurs via the process that is known as the 'stochastic stabilization', or the 'stabilization by noise') are found applying the Khasminskii-type Lyapunov functions.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"19-34"},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139643727","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

Dosage optimization for reducing tumor burden using a phenotype-structured population model with a drug-resistance continuum. 利用具有耐药性连续体的表型结构群体模型优化剂量，减轻肿瘤负担。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-03-15 DOI: 10.1093/imammb/dqae003

Lifeng Han, Osman N Yogurtcu, Marisabel Rodriguez Messan, Wencel Valega-Mackenzie, Ujwani Nukala, Hong Yang

{"title":"Dosage optimization for reducing tumor burden using a phenotype-structured population model with a drug-resistance continuum.","authors":"Lifeng Han, Osman N Yogurtcu, Marisabel Rodriguez Messan, Wencel Valega-Mackenzie, Ujwani Nukala, Hong Yang","doi":"10.1093/imammb/dqae003","DOIUrl":"10.1093/imammb/dqae003","url":null,"abstract":"Drug resistance is a significant obstacle to effective cancer treatment. To gain insights into how drug resistance develops, we adopted a concept called fitness landscape and employed a phenotype-structured population model by fitting to a set of experimental data on a drug used for ovarian cancer, olaparib. Our modeling approach allowed us to understand how a drug affects the fitness landscape and track the evolution of a population of cancer cells structured with a spectrum of drug resistance. We also incorporated pharmacokinetic (PK) modeling to identify the optimal dosages of the drug that could lead to long-term tumor reduction. We derived a formula that indicates that maximizing variation in plasma drug concentration over a dosing interval could be important in reducing drug resistance. Our findings suggest that it may be possible to achieve better treatment outcomes with a drug dose lower than the levels recommended by the drug label. Acknowledging the current limitations of our work, we believe that our approach, which combines modeling of both PK and drug resistance evolution, could contribute to a new direction for better designing drug treatment regimens to improve cancer treatment.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"35-52"},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139975237","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

Impact of climate change on vegetation patterns in Altay Prefecture, China. 气候变化对中国阿勒泰地区植被格局的影响。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-03-15 DOI: 10.1093/imammb/dqae002

Li Li, Yi-Zhi Pang, Gui-Quan Sun, Shigui Ruan

{"title":"Impact of climate change on vegetation patterns in Altay Prefecture, China.","authors":"Li Li, Yi-Zhi Pang, Gui-Quan Sun, Shigui Ruan","doi":"10.1093/imammb/dqae002","DOIUrl":"10.1093/imammb/dqae002","url":null,"abstract":"Altay Prefecture, a typical arid region in northwestern China, has experienced the climate transition from warming-drying to warming-wetting since 1980s and has attracted widespread attention. Nonetheless, it is still unclear how climate change has influenced the distribution of vegetation in this region. In this paper, a reaction-diffusion model of the climate-vegetation system is proposed to study the impact of climate change (precipitation, temperature and carbon dioxide concentration) on vegetation patterns in Altay Prefecture. Our results indicate that the tendency of vegetation growth in Altay Prefecture improved gradually from 1985 to 2010. Under the current climate conditions, the increase of precipitation results in the change of vegetation pattern structures, and eventually vegetation coverage tends to be uniform. Moreover, we found that there exists an optimal temperature where the spot vegetation pattern structure remains stable. Furthermore, the increase in carbon dioxide concentration induces vegetation pattern transition. Based on four climate change scenarios of the Coupled Model Intercomparison Project Phase 6 (CMIP6), we used the power law range (PLR) to predict the optimal scenario for the sustainable development of the vegetation ecosystem in Altay Prefecture.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"53-80"},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139992245","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

Effects of vaccination on the two-strain transmission dynamics of COVID-19: Dougherty County, Georgia, USA, as a case study. 疫苗接种对COVID-19两株传播动态的影响:以美国乔治亚州多尔蒂县为例

Mathematical medicine and biology : a journal of the IMA Pub Date : 2023-12-15 DOI: 10.1093/imammb/dqad007

Buddhi Pantha, Jemal Mohammed-Awel, Naveen K Vaidya

{"title":"Effects of vaccination on the two-strain transmission dynamics of COVID-19: Dougherty County, Georgia, USA, as a case study.","authors":"Buddhi Pantha, Jemal Mohammed-Awel, Naveen K Vaidya","doi":"10.1093/imammb/dqad007","DOIUrl":"10.1093/imammb/dqad007","url":null,"abstract":"The emergence of multiple strains of SARS-COV-2 has made it complicated to predict and control the COVID-19 pandemic. Although some vaccines have been effective in reducing the severity of the disease, these vaccines are designed for a specific strain of the virus and are usually less effective for other strains. In addition, the waning of vaccine-induced immunity, reinfection of recovered people, and incomplete vaccination are challenging to the vaccination program. In this study, we developed a detailed model to describe the multi-strain transmission dynamics of COVID-19 under vaccination. We implemented our model to examine the impact of inter-strain transmission competition under vaccination on the critical outbreak indicators: hospitalized cases, undiagnosed cases, basic reproduction numbers, and the overtake-time by a new strain to the existing strain. In particular, our results on the dependence of the overtake-time on vaccination rates, progression-to-infectious rate, and relative transmission rates provide helpful information for managing a pandemic with circulating two strains. Furthermore, our results suggest that a reduction in the relative transmission rates and a decrease in vaccination dropout rates or an increase in vaccination rates help keep the reproduction number of both strains below unity and keep the number of hospitalized cases and undiagnosed cases at their lowest levels. Moreover, our analysis shows that the second and booster-dose vaccinations are useful for further reducing the reproduction number.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"308-326"},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"107593169","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

Which airways should we treat? Structure-function relationships and estimation of the singular input modes from the forward model alone. 我们应该治疗哪种呼吸道？结构-函数关系以及仅从正向模型对奇异输入模式的估计。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2023-12-15 DOI: 10.1093/imammb/dqad006

Graham M Donovan

引用次数: 0

Pattern formation and travelling waves in a multiphase moving boundary model of tumour growth. 肿瘤生长多相移动边界模型的模式形成和行波。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2023-12-15 DOI: 10.1093/imammb/dqad008

Jacob M Jepson, Reuben D O'Dea, John Billingham, Nabil T Fadai

{"title":"Pattern formation and travelling waves in a multiphase moving boundary model of tumour growth.","authors":"Jacob M Jepson, Reuben D O'Dea, John Billingham, Nabil T Fadai","doi":"10.1093/imammb/dqad008","DOIUrl":"10.1093/imammb/dqad008","url":null,"abstract":"We employ the multiphase, moving boundary model of Byrne et al. (2003, Appl. Math. Lett., 16, 567-573) that describes the evolution of a motile, viscous tumour cell phase and an inviscid extracellular liquid phase. This model comprises two partial differential equations that govern the cell volume fraction and the cell velocity, together with a moving boundary condition for the tumour edge, and here we characterize and analyse its travelling-wave and pattern-forming behaviour. Numerical simulations of the model indicate that patterned solutions can be obtained, which correspond to multiple regions of high cell density separated by regions of low cell density. In other parameter regimes, solutions of the model can develop into a forward- or backward-moving travelling wave, corresponding to tumour growth or extinction, respectively. A travelling-wave analysis allows us to find the corresponding wave speed, as well as criteria for the growth or extinction of the tumour. Furthermore, a stability analysis of these travelling-wave solutions provides us with criteria for the occurrence of patterned solutions. Finally, we discuss how the initial cell distribution, as well as parameters related to cellular motion and cell-liquid drag, control the qualitative features of patterned solutions.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"327-347"},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138300845","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