12Bet官网第四届“生物数学”国际论坛
值此12Bet官网建校二十周年之际,为了进一步加强国内外学术交流,推动12Bet官网数学学科建设,促进生物数学平台建设,营造良好的学术研究氛围,特举办12Bet官网第四届“生物数学”国际论坛。
生物数学建模应用及传染病防控
2022年6月11-12日 上午8:20-下午17:20
线下:12Bet官网求索楼报告厅
线上:腾讯会议(会议号:98721366478)
●主持人
线下主持:潘志明教授,12Bet官网副校长
线上主持:朱怀平教授,约克大学应用数学首席教授,12Bet官网名誉教授
介绍嘉宾和学校领导
12Bet官网刘志远校长致辞
专家报告
报告安排
报告日期 |
报告时间 |
报告名称 |
报告人 |
主持人 |
6月11日 |
8:40-9:20 |
异质性传染病动力学模型与应用 |
崔景安 |
朱怀平 |
9:20-10:00 |
Delayed regulation in physiology and epidemiology |
Jacques Bélair |
10:00-10:40 |
Computational Fluid Dynamics Modeling of indoor aerosol transmission of COVID-19 and other airborne diseases |
Marina Freire-Gormaly |
10:40-11:20 |
Modeling and research on an immuno-epidemiological coupled system with coinfection |
李学志 |
高洁 |
11:20-12:00 |
具有空间异质性的流感传播及控制 |
王玮明 |
Break |
6月11日 |
14:00-14:40 |
Traveling pulse solutions of generalized Keller-Segel systems |
杜增吉 |
李学志 |
14:40-15:20 |
依从性与药物动力学及在HIV治疗中的应用 分析 |
唐三一 |
15:20-16:00 |
Global Threshold Dynamics of SIQS Model in Time Fluctuating Environment |
范 猛 |
16:00-16:40 |
Interlocked feedback loops balance the adaptive immune response |
杨 凌 |
杜增吉 |
16:40-17:20 |
Modeling the role of macrophages in HIV persistence during antiretroviral therapy |
邱志鹏 |
Break |
6月12日 |
8:00-8:40 |
A stochastic model explains the peri-odicity phenomenon of influenza on network |
靳 祯 |
范猛 |
8:40-9:20 |
基于癌症组学数据的数学模型及算法研究 |
高 洁 |
9:20-10:00 |
Persistence, global stability, and global Hopf bifurcation in a staged tick population model with delays |
范桂红 |
10:00-10:40 |
Mathematical modeling of infectious diseases |
王稳地 |
陆海霞 |
10:40-11:20 |
西尼罗河病毒的空间扩散及其风险刻画 |
林支桂 |
11:20-12:00 |
Modelling and dynamics of sweet potato weevilcontrol using natural enemies |
朱怀平 |
专家简介
(依报告顺序)
崔景安,北京建筑大学教授,博士生导师.中国数学学会理事,中国生物数学专业委员会主任,北京市学术创新团队负责人.《International Journal of Biomathematics》编委.主要研究生物数学中的传染病动力学模型,生物动力系统.主持国家自然科学基金项目5项,主要教学科研成果获得了教育部自然科学奖一等奖1项、教育部自然科学奖二等奖2项,北京市教育教学成果奖一等奖1项.
Jacques Bélair,Full Professor in the Department of mathematics and statistics at Université de Montréal. He has a PhD in applied mathematics from Cornell University and he was a postdoctoral fellow in the Department of Physiology at McGill University. He has served as associate director of the Centre de recherches mathématiques (CRM) and vice-dean of the Faculty of Graduate and Postdoctoral Studies at Université de Montréal, President of the Canadian Applied and Industrial Mathematics Society (CAIMS) and co-chaired the Organizing Committee of the Annual Meeting of the Society for Mathematical Biology (SMB) in 2019. His research concerns mathematical modeling of dynamic regulatory processes in biology: in the past, cardiac arrhythmias and motor control, presently, blood cell production (hematopoiesis) and the propagation of infectious diseases in general, and currently COVID-19 in particular. He was a member of the Canadian Mathematical Modeling of COVID-19 Task Force, and is currently involved in the Canadian Emerging and Infectious Diseases Modeling Networks "One Health Modelling Network for Emerging Infections" and "Mathematics of Public Health", and serves as co-director for the Canadian Centre for Disease Modelling.
Marina Freire-Gormaly,Assistant Professor in Mechanical Engineering Department at the Lassonde School of Engineering at York University. Her research spans Computational Fluid Dynamics modeling of COVID-19 aerosols in indoor environments, water treatment systems and energy recovery systems for remote communities that lack access to grid electricity and developing new technologies. She also is interested in machine learning applications for smart design of innovative energy and water systems. She completed her Ph.D., M.A.Sc. and BASc., from the University of Toronto in Mechanical Engineering. She currently serves as the Chair of Student Affairs for the Canadian Society of Mechanical Engineers (CSME). She is passionate about research and teaching energy systems to inspire the next generation of engineers to tackle society’s growing sustainability challenges. Her research interests include energy systems, optimization and design for global engineering contexts.
李学志,河南财政金融学院校长,二级教授,博士生导师.河南省优秀专家,河南省基础研究领军人才,教育部数学类专业教学指导委员会委员,中国数学会生物数学专业委员会副主任.主要研究领域:应用泛函分析,生物数学,传染病动力学.主持国家自然科学基金面上项目5项,在德国Springer出版社出版学术著作2部,在SCI收录期刊发表学术论文100余篇,20次应邀到美国、意大利、英国、加拿大、日本、韩国、印度等国访问交流.
王玮明,淮阴师范学院“翔宇学者”、博士、教授,中国数学会生物数学专委会常务理事、副秘书长,中国工业与应用数学会数学与生命科学专委会理事.江苏省十四五“数学”重点学科带头人,江苏省高校科技创新团队“传染病防控的建模分析及预警系统”带头人,淮安市传染病防控及预警重点实验室主任.曾入选浙江省“新世纪151人才工程”第二层次,担任浙江省十二五“应用数学”重点学科带头人.近十年来专注于传染病防控的建模分析及预警研究,得到了完成国家自然科学基金的连续资助,已主持完成面上项目2项,目前主持在研1项,在科学出版社出版专著1部.近五年来,获中国产学研合作与创新成果奖优秀奖、海南省自然科学奖二等奖和新疆自治区科技进步奖二等奖各1项.入选爱思唯尔2020、2021 “中国高被引学者”以及2021科睿唯安“全球高被引科学家”等榜单.
杜增吉,江苏师范大学副校长、教授、博士生导师.中国数学会奇异摄动专业委员会副理事长,江苏省优秀教育工作者,江苏省“333高层次人才”中青年科技领军人才和中青年科学技术带头人,江苏省“青蓝工程”中青年学术带头人.研究方向为微分方程与动力系统、奇异摄动理论及其应用、生物数学等,在J. Funct. Anal.,J. Nonlinear Sciences, J. Differential Equations, J. Math. Biol.等期刊上发表论文80余篇.主持国家自然科学基金项目5项,获得江苏省数学成就奖,江苏省优秀教学成果奖,山东省自然科学奖二等奖等.
唐三一,陕西师范大学科学技术处处长、教授、博士生导师. 2003年中国科学院数学所获得博士学位,2003年至2007年在英国Warwick大学从事交叉学科研究,此后先后到加拿大、美国、日本、德国、法国等国知名大学从事合作研究或多次应邀作生物数学国际大会特邀报告.研究成果在害虫综合治理策略设计、突发性传染病预测预警、药动学参数确定、肿瘤综合治疗与药物毒理效应等方面产生了非常重要的影响,发表SCI论文130多篇,被SCI杂志引用超过7200次.主持1项国家自然科学基金重点项目,参与1项国家自然科学基金重点项目(第二参与人),完成或主持数理、信息、医学等不同学部国家自然科学基金6项(4项面上、1项中美生物医学国际合作和1项数学天元访学项目),研究成果获陕西省自然科学二等奖1项(第一完成人).2018年获陕西省科技创新领军人才称号,2022年聘为“国务院联防联控机制科研攻关组疫苗研发专班专家组成员”.
范猛,东北师范大学数学与统计学院院长、二级教授、博士生导师.主要从事非线性动力学系统和生物数学研究,出版专著和教材各1部,共同主编论文集和进展特刊7部,发表科研论文百余篇,主持NSFC和省部级项目13项,连续六年入选Elsevier中国高被引学者.获国务院政府特殊津贴、教育部新世纪优秀人才、吉林省首批长白山学者特聘教授、吉林省高级专家等荣誉,获教育部自然,获宝钢教育奖优秀教师奖、明德教师奖、吉林省高等教育教学成果奖等教学奖励.曾在美国Arizona State University和Purdue University、加拿大York University和University of Alberta、日本Shimane University和Osaka Prefecture University等进行学术访问.现任4种期刊编委、中国数学会常务理事、中国数学会生物数学专业委员会副主任、吉林省数学会秘书长、吉林省工业与应用数学学会副理事长等.
杨凌,苏州大学数学科学学院、系统生物学研究中心教授、博士生导师.长期从事生物系统的数学模型方面工作,主要包括:细胞周期,蛋白质-蛋白质作用网络,心肌细胞新陈代谢网络,以及生理节律,基因敲除小鼠表型数据分析等方面的研究.主要成果发表在Physical Review Letters, Biophysical Journal (Cell子刊),Cell Death and Differentiation(Nature杂志社),Nucleic acids research(IF >10), PLoS Genetics (Nature index)、Journal of Biological Chemistry等Top Journal上,担任国家重点研发计划重点专项课题(774万)负责人,主持四个国家自然科学基金面上项目.担任中国工业与应用数学会理事、中国工业与应用数学会数学生命科学分会常务理事、中国细胞生物学会生物节律专业委员会委员、中国数学会生物数学专业委员会委员等职务.
邱志鹏,南京理工大学江阴校区基础前沿交叉中心主任、教授、博士生导师.主要从事常微分方程、动力系统与生物数学的研究工作,正在或完成主持国家自然科学基金4项,国家自然科学基金国际合作基金1项,教育部留学回国基金1项,参加国家自然科学基金面上项目2项和江苏省自然科学基金青年项目1项,目前已在Bull. Math. Biol., Math. Biosci., J. Diff. Equs., SIAM J. Appl. Math., J. Math. Biol., J. Theor. Biol., J. Math. Anal. Appl.等期刊上发表论文70余篇,曾先后访问过美国Purdue大学、Florida大学,意大利Trento大学、加拿大York大学和Alberta大学.
靳祯,山西大学数学科学学院院长、二级教授、博士生导师.中国数学会生物数学专业委员会副主任,山西省“疾病防控的数学技术与大数据分析”重点实验室主任,山西省数学会理事长,享受国务院政府特殊津贴.主要从事生物动力系统研究.曾获山西省科学技术奖(自然科学类)一等奖2项,教育部高等学校优秀成果二等奖奖(自然科学类)1项.
高洁,江南大学理学院副院长、教授、博士生导师. “十四五”江苏省重点学科带头人,中国交叉科学学会常务理事,中国工业与应用数学学会数学生命科学专委会理事,中国运筹学会计算系统生物学专委会理事,江苏省数学学会理事,江苏省概率统计学会常务理事,无锡市现场统计研究会理事长.主要研究方向:计算系统生物学、生物信息学、生物统计学等.获全国素质教育先进工作者、无锡市科协学会系统优秀共产党员、荣智权奖教金.已在Briefings in Bioinformatics等国际国内学术刊物上发表高水平学术论文50多篇,出版学术专著1部、教材2部,授权发明专利1项.主持在研国家自然科学基金重点项目课题1项,主持或主要参与完成国家自然科学基金重大研究计划集成项目、面上项目、中央高校基础研究专项经费项目、横向项目等8项.获中国轻工业联合会科学技术三等奖、中国商业联合会科学技术三等奖、无锡市自然科学优秀学术论文一等奖各1项,获全国素质教育教研成果一等奖1项,校教学成果一等奖2项、二等奖1项.
范桂红,美国哥伦布州立大学数学系主任,加拿大麦克马斯特大学(McMaster Univeristy)博士,约克大学(York Univesity)博士后.主要研究兴趣为泛函微分方程理论及其在生物数学中的应用,特别是时间滞后系统在媒介传播疾病中的建模,理论分析,及其优化控制.具体的研究课题包括以蚊子为媒介的西尼罗病的传播及其预防,以蜱虫为媒介的莱姆病在全球暖化下的影响.已在Journal of Dynamics and Differential Equations, Journal of Mathematical Biology, Journal of Differential Equations, One Health, Transboundary and Emerging Disease等国际刊物发表论文三十余篇.曾在美国国家自然科学基金与美国女性数学会联合的“Mentoring Travel Grant"支持下在Nimbio访学科研一个月,多次被邀请在微分方程方向的主要会议作学术报告.作为合作组织者,多次向美国数学年(JMM)、生物数学年会(SMB)和SIAM年会,组织小组报告(Scientific Special Sessions).
王稳地,西南大学二级教授、博士生导师.中国数学会生物数学专业委员会副主任. 2005年获得重庆市名师称号, 2018年获得重庆市最美教师称号.从事生物数学的研究,在种群动力学和传染病动力学建模和分析方面发表论文100多篇,7次入选Elsevier数学类高引用论文作者,已经主持国家自然科学基金课题7项、教育部项目2项.
林支桂,扬州大学教授、博士生导师.中国数学会生物数学专业委员会副主任、《生物数学学报》和《Int. J. Biomath.》杂志编委.曾赴丹麦科技大学留学一年,在韩国浦项科技大学作博士后研究.多次应邀到丹麦科技大学、新加坡国立大学、韩国浦项科技大学、高丽大学、澳大利亚New England大学、加拿大York大学等作短期学术访问.从事应用数学方面的研究,已出版专著一部,发表论文100余篇,主持国家自然科学基金8项、省部级项目6项. 2021年获江苏省自然科学奖三等奖.
朱怀平,加拿大约克大学应用数学首席教授,约克大学疾病建模中心(CCDM)、并行计算与模拟实验室(LAMPS)和加拿大人畜共患病建模中心(OMNI)主任.长期从事分支理论及其应用、希尔伯特第十六问题、种群生态学与传染病学的数学分析研究、气候变化模拟和影响、以及蚊虫疾病的实时预报和控制等研究工作.在数学及生物数学的国际顶级或高水平期刊上累计发表文章120多篇,解决了著名的希尔伯特第16问题关于幂零图周期重数有限性的问题,是动力系统分支理论和应用领域著名专家,曾获加拿大国家创新基金会基础创新奖、安大略省青年科学研究奖等多种奖项.作为项目负责人和主要参与者获得加拿大自然科学和工程研究委员会(NSERC)、加拿大公共卫生部(PHAC)、加拿大卫生研究院(CIHR)、加拿大创新基金会(CFI)和加拿大安大略省相关部委等资助。他领导LAMPS团队建立了安大略省气候数据门户以支持安大略省和加拿大的气候行动。朱教授目前主持加拿大NSERC-PHAC共同资助的大型创新团队项目“新兴感染的共同健康建模(OMNI)”,资助经费250万加币.
报告摘要
(依报告顺序)
报告1异质性传染病动力学模型与应用(崔景安)
报告1摘要:传染病的传播与控制过程中,基本再生数、最终规模、免疫策略问题的研究至关重要.针对异质的多群组传染病模型探讨了基本再生数与最终规模的关系,应用于一些传染病案例与免疫策略的研究.
报告2Delayed regulation in physiology and epidemiology(Jacques Bélair)
报告2摘要:The description of the regulation of many biological processes involves the incorporation of explicit time delays to account for such elements as the latency period in infection, or the maturation interval in proliferating cell production. By developing biologically correct models of these systems, we are naturally lead to the investigation of nonlinear systems of delay-differential equations, some with state-dependent delays, which we can investigate to establish dynamical properties (stability, bifurcations) of the underlying systems. I will present two classes of examples where such analysis has been performed: interacting populations in which a virus is circulating, and models for instabilities in erythropoiesis (red blood cell production) and thrombopoiesis (platelet production).
报告3Computational Fluid Dynamics Modeling of indoor aerosol transmission of COVID-19 and other airborne diseases(Marina Freire-Gormaly)
报告3摘要:Amid the COVID-19 pandemic and in an era of climate change with emerging infectious diseases, concerns arise as to how the ventilation configuration in indoor environments can affect airborne transmission routes. The ventilation techniques required to mitigate airborne transmission are unique to each space, and thorough research to determine the unique needs of various spaces is still lacking. The study focuses on developing a method to determine the risk factors associated with various ventilation configurations, complex room dimensions and dependence of index host location in the domain. The method consists of computational fluid dynamics (CFD) studies to determine possible transport phenomena in different conditions and simulating various possible infection source locations to determine the range of risk scenarios. After a verified method is developed to quantify risk factors based on the above-mentioned parameters, future work can incorporate various room dimensions, occupancies and HVAC designs to determine the risk of transmission associated with commonly used spaces.
报告4Modeling and research on an immuno-epidemiological coupled system with coinfection(李学志)
报告4摘要:In this talk, a two-strain model with coinfection that links immunological and epidemiological dynamics across scales is formulated. On the with-in host scale, the two strains eliminate each other with the strain having the larger immunological reproduction number persisting. However, on the population scale coinfection is a common occurrence. Individuals infected with strain one can become coinfected with strain two, and similarly for individuals originally infected with strain two. The immunological reproduction numbers Rj , the epidemiological reproduction numbers Rj and invasion reproduction numbers Rij are computed. Besides the disease-free equilibrium, there are strain one and strain two dominance equilibria. The disease-free equilibrium is locally asymptotically stable when the epidemiological reproduction numbers Rj are smaller than one. In addition, each strain dominance equilibrium is locally asymptotically stable if the corresponding epidemiological reproduction number is larger than one and the invasion reproduction number of the other strain is smaller than one. The coexistence equilibrium exists when all the reproduction numbers are greater than one. Simulations suggest that when both invasion reproduction numbers are smaller than one bistability occurs with one of the strains persisting or the other, depending on initial conditions.
报告5具有空间异质性的流感传播及控制(王玮明)
报告5摘要:主要介绍异质环境中具有一般发病率的SIRS流感模型的传播动力学,建立了流感模型的全局阈值动力学:如果基本再生数R_0<1,则模型存在唯一无病平衡点且全局渐近稳定,不存在地方病平衡点;如果R_0<1,模型至少存在一个地方病平衡点且是一致持续的.研究结果表明:流感的空间异质性会增加流感的感染风险,要控制流感的传播,必须提高流感的恢复率和传播率的空间异质性,或者改变出行计划尽可能留在家里以降低扩散.
报告6Traveling pulse solutions of generalized Keller-Segel systems(杜增吉)
报告6摘要:In this talk, we are concerned with the existence of traveling pulse solutions of one-dimensional generalized Keller-Segel system with nonlinear chemical gradients and small cell diffusion by using the dynamical systems approach. To show the existence of traveling pulse solutions, we first analyze the dynamics of the system by geometric singular perturbation theory. And then we seek an invariant region for the associated traveling wave equation. Finally, we apply Poincare-Bendixson theorem to analyze the flow on this invariant region to obtain the existence of traveling pulse solutions in this bounded invariant region. This talk is based on joint work with Jiang Liu and Yulin Ren.
报告7依从性与药物动力学及在HIV治疗中的应用分析(唐三一)
报告7摘要:本报告将介绍如何根据不同给药方式和消除速率构建单舱室药物动力学模型,重点说明模型解析求解公式的重要性及其求解过程.然后介绍个体依从性驱动的随机药物动力学模型的构建方法,相关模型解的均值与期望以及解的极限分布的存在性.最后简单介绍如何融合药物动力学、药物效应学与HIV抗病毒治疗,特别是分析个体依从性对HIV抗病毒治疗的影响.
报告8Global Threshold Dynamics of SIQS Model in Time Fluctuating Environment(范猛)
报告8摘要:The global threshold dynamics of an SIQS model in fluctuating environments are explored. Criteria are established for the permanence and extinction of the infective in general nonautonomous scenario. In particular, an environment varying periodically in time is further considered. The global threshold dynamics (i..e, the existence and global asymptotic stability of the disease-free periodic solution, the existence of the endemic periodic solution and the permanence of the infective) are completely characterized by the basic reproduction number defined by the spectral radius of an associated linear integral operator.
报告9Interlocked feedback loops balance the adaptive immune response(杨凌)
报告9摘要:Adaptive immune responses can be activated by harmful stimuli. Upon activation, a cascade of biochemical events ensues the proliferation and the differentiation of T cells, which can remove the stimuli and undergo cell death to maintain immune cell homeostasis. However, normal immune processes can be disrupted by certain dysregulations, leading to pathological responses, such as cytokine storms and immune escape. In this paper, a qualitative mathematical model, composed of key feedback loops within the immune system, was developed to study the dynamics of various response behaviors. First, simulation results of the model well reproduce the results of several immune response processes, particularly pathological immune responses. Next, we demonstrated how the interaction of positive and negative feedback loops leads to irreversible bistable, reversible bistable and monostable,which characterize different immune response processes: cytokine storm, normal immune response, immune escape. The stability analyses suggest that the switch-like behavior is the basis of rapid activation of the immune system, and a balance between positive and negative regulation loops is necessary to prevent pathological responses. Furthermore, we have shown how the treatment moves the system back to a healthy state from the pathological immune response. The bistable mechanism that revealed in this work is helpful to understand the dynamics of different immune response processes.
报告10Modeling the role of macrophages in HIV persistence during antiretroviral therapy(邱志鹏)
报告10摘要:HIV preferentially infects activated CD4+Tcells.Current antiretroviral therapy cannot eradicate the virus. Viral infection of other cells such as macrophages may contribute to viral persistence during antiretroviral therapy. In addition to cell-free virus infection, macrophages can also get infected when engulfing infected CD4+ T cells as innate immune sentinels. How macrophages affect the dynamics of HIV infection remains unclear. In this paper, we develop an HIV model that includes the infection of CD4+ T cells and macrophages via cell-free virus infection and cell-to-cell viral transmission. We derive the basic reproduction number and obtain the local and global stability of the steady states. Sensitivity and viral dynamics simulations show that even when the infection of CD4+ T cells is completely blocked by therapy, virus can still persist and the steady-state viral load is not sensitive to the change of treatment efficacy. Analysis of the relative contributions to viral replication shows that cell-free virus infection leads to the majority of macrophage infection. Viral transmission from infectedCD4+Tcells to macrophages during engulfment accounts for a small fraction of the macrophage infection and has a negligible effect on the total viral production. These results suggest that macrophage infection can be a source contributing to HIV persistence during suppressive therapy. Improving drug efficacies in heterogeneous target cells is crucial for achieving HIV eradication in infected individuals. This is a joint work with Ting Guo and Libin Rong.
报告11A stochastic model explains the periodicity phenomenon of influenza on network(靳祯)
报告11摘要:In this talk, based on the randomness of population number and the heterogeneity of population contact, we have established a stochastic infectious disease model about influenza based on the degree of the network, and obtained the power spectral density function by using the van Kampen expansion method of the master equation. The relevant parameters are obtained by fitting the influenza data of sentinel hospitals.
报告12基于癌症组学数据的数学模型及算法研究(高洁)
报告12摘要:With the development of high-throughput technologies, the accumulation of large amounts of multidimensional genomic data provides an excellent opportunity to study the multilevel biological regulatory relationships in cancer. Based on the hypothesis of ceRNA network, lncRNAs can eliminate the inhibition of miRNAs on their target genes by binding to intracellular miRNA sites so as to improve the expression level of these target genes. However, previous studies on cancer expression mechanism are mostly based on individual or two-dimensional data, and lack of integration and analysis of various RNA-seq data, making it difficult to verify the complex biological relationships involved. To explore RNA expression patterns and potential molecular mechanisms of cancer, a network-regularized sparse orthogonal-regularized joint nonnegative matrix factorization (NSOJNMF) algorithm is proposed, which combines the interaction relations among RNA-seq data in the way of network regularization and effectively prevents multicollinearity through sparse constraints and orthogonal regularization constraints to generate good modular sparse solutions. NSOJNMF algorithm is performed on the datasets of liver cancer and colon cancer, then ceRNA co-modules of them are recognized. The enrichment analysis of these modules shows that>90% of them are closely related to the occurrence and development of cancer. In addition, the ceRNA networks constructed by the ceRNA co-modules not only accurately mine the known correlations of the three RNA molecules but also further discover their potential biological associations, which may contribute to the exploration of the competitive relationships among multiple RNAs and the molecular mechanisms affecting tumor development.
报告13Persistence, global stability, and global Hopf bifurcation in a staged tick population model with delays(范桂红)
报告13摘要:Transmitted by ticks, Lyme disease is an emerging infectious disease which can cause severe problems for human health. The reproduction and development of ticks are closely related to the environmental factors, in particularly the daily temperature. We study a three-stage population model for ticks with three delays to reflect the impact of average daily temperature on the developmental stages. We define the basic reproduction number R0 of tick population. The tick population is uniformly persistent if R0 > 1. In addition,if 1 < R0 < e^2, then the unique positive equilibrium point is globally asymptotically stable. If R0 > e^2, the positive equilibrium could lose stability through the occurrence of a Hopf bifurcation and the system shows oscillatory behaviors. Recently, we proved the existence of global Hopf bifurcation as bifurcation parameters vary. To illustrate our theoretical results, we present some global Hopf bifurcation diagrams as delays vary and some numerical solutions of the model.
报告14Mathematical modeling of infectious diseases(王稳地)
报告14摘要:First, I will talk about scarlet fever, whichis an acute respiratory infectious disease with the increasing incidencerate from 2011 throughout the world. We propose the mathematical models that incorporate both direct transmissions and indirect transmissions of scarlet fever. The threshold conditions for disease invasion are obtained in terms of the basic reproduction number. The peak value, final size and epidemic time in a seasonal prevalence are investigated numerically. Furthermore, the effects of seasonal fluctuations on disease outbreak are also studied on the basis of real data in China. Second, I introduce the model of age-structured pertussis model with covert infection. It is shown that although the vaccine coverage rate is relativelyhigh, the model has a backward bifurcation for a larger covert infection rate. This highlights the importance to control the covert infections.
报告15西尼罗河病毒的空间扩散及其风险刻画(林支桂)
报告15摘要:我们用反应扩散方程组描述西尼罗河病毒的空间扩散,用自由边界表示病毒扩散的边沿.为了检查空间特征对病毒扩散的影响,我们定义了四个基本再生数,分别对应于常微分方程组问题、具齐次Neumann问题,齐次Dirichlet问题和自由边界问题.结果表明,在高风险区域,如果感染区域范围大或者扩散慢,病毒将蔓延;在低风险区域,小的初始感染病例,小的感染范围和大的扩散速率有利于病毒的消退.另外我们还考察了全球气候变暖,空间异质性、区域演化和季节演化对西尼罗河病毒扩散的影响.
报告16Modelling studies and population dynamics of sweet potato weevil(朱怀平)
报告16摘要:Sweet potato weevil is the most serious pest of sweet potato worldwide. It causes damage in the field, in storage, and is of quarantine significance. The reproduction of go through egg, larva, pupa amd adult four stages, with a complicated cycle of one to two months depending on season. The generations are indistinct and the number of generations occurring annually varies. All stages can be found throughout the year if suitable host material is available. In this talk, I will present a simplified stage structure model for the population of sweet potato weevil in a field of sweet potatoes emphasizing on the harmful stage of adult and larvae which is more predominant. I will also report our preliminary results of the model which would be helpful in understanding the population dynamics for controlling such pest in the sweet potato field. This is a joint work with Haixia Lu, Zengji Du and Zongyun Li.