A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,t...A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,the aging rates between two age groups are set to be constant.The existence-and-uniqueness of global positive solution is firstly showed.Then,by constructing several appropriate Lyapunov functions and using the high-dimensional Itô’s formula,the sufficient conditions for the stochastic extinction and stochastic persistence of the exposed individuals and the infected individuals are obtained.The stochastic extinction indicator and the stochastic persistence indicator are less-valued expressions compared with the basic reproduction number.Meanwhile,the main results of this study are modified into multi-age groups.Furthermore,by using the surveillance data for Fujian Provincial Center for Disease Control and Prevention,Fuzhou COVID-19 epidemic is chosen to carry out the numerical simulations,which show that the age group of the population plays the vital role when studying infectious diseases.展开更多
Stochastic switched epidemic systems with a discrete or distributed time delay are constructed and investigated. By the Lyapunov method and lto＇s differential rule, the existence and uniqueness of global positive sol...Stochastic switched epidemic systems with a discrete or distributed time delay are constructed and investigated. By the Lyapunov method and lto＇s differential rule, the existence and uniqueness of global positive solution of each system is proved. And stability conditions of the disease-free equilibrium of the systems are obtained. Numerical simulations are presented to illustrate the results.展开更多
Porcine epidemic diarrhea(PED)is caused by porcine epidemic diarrhea virus(PEDV),and is characterized by vomiting,diarrhea and dehydration of suckling pigs from 80% to 100% morbidity and 50% to 90% mortality,and resul...Porcine epidemic diarrhea(PED)is caused by porcine epidemic diarrhea virus(PEDV),and is characterized by vomiting,diarrhea and dehydration of suckling pigs from 80% to 100% morbidity and 50% to 90% mortality,and resulted in tremendous economic losses to swine industry.The PEDV mainly infects small intestine of pigs,resulting in vacuolar degeneration and necrosis of mucosal epithelium.The IPEC-J2 is a pig intestine epithelial cell line,which is similar to the intestinal environment of piglets,can be used to isolate and identify the PEDV field isolates.In this study,it appeared the PEDV typical postmortem changes and histopathological lesion of degeneration and destruction of small intestine in infected piglets,and IHC identified that the PEDV distributed in the mucosa and submucosa of small intestine mostly.Furthermore,the PEDV HLJ strain was successfully isolated and characterized in the IPEC-J2 cells,and indicated that the IPEC-J2 cell line was sensitive to isolate and adapt the PEDV field strain,and could be utilized to multiply the PEDV rapidly.The S gene analysis indicated that the PEDV HLJ strain was the prevailed virus,belonged to Group 1 with attenuated virulent DR13,SC1402 and J-S2/2015 strains isolated in South Korea and China from 2014 to 2015.This study had important theoretical and practical significances on analyzing genetic variation of the PEDV,understanding the pathogenic characteristics of the virus and developing new vaccines for the PED.展开更多
The p65 protein is a functional subunit of NF-κB family and exhibits a crucial role in host immune and inflammatory responses,apoptosis and tumor proliferation if improperly-regulated.Given its ubiquitous association...The p65 protein is a functional subunit of NF-κB family and exhibits a crucial role in host immune and inflammatory responses,apoptosis and tumor proliferation if improperly-regulated.Given its ubiquitous association with nearly all the animal cells and its pleotropic functions,the gene encoding NF-κB p65 subunit was cloned and sequenced from porcine kidney(PK-15)cells.The gene was 1662 bp in length,encoded a 553-amino acid protein and contained the prototypical NF-κB functional domains.Real-time quantitative RT-PCR and Western blot were used to characterize the transcription and expression levels of the p65 in different pig tissues.The results indicated that the p65 gene and protein were both broadly expressed in pig tissues,but most highly expressed in the intestine-associated lymph nodes and the lungs.To localize the recombinant protein in intestinal porcine epithelial cells(IPEC-J2),the gene was subcloned into the vector pEGFP(pEGFP-p65).Using fluorescence microscopy,the protein was found confined to the cytoplasm in normal cells;however,during porcine epidemic diarrhea virus(PEDV)infection,mRNA and protein expression were significantly up-regulated and the protein exhibited an overt tendency for nuclear translocalization consistent with a regulatory role in antiviral innate immunity.展开更多
为了应对容迟网络中拓扑结构剧烈变化、节点间连接频繁中断等问题,报文通常采用"存储—携带—转发"的方式进行传输:节点将报文存储在缓存中,携带报文直到遇到合适的机会才将报文转发给其他节点.因为缓存有限,这样的传输方式...为了应对容迟网络中拓扑结构剧烈变化、节点间连接频繁中断等问题,报文通常采用"存储—携带—转发"的方式进行传输:节点将报文存储在缓存中,携带报文直到遇到合适的机会才将报文转发给其他节点.因为缓存有限,这样的传输方式会使节点缓存溢出,导致拥塞的发生.在容迟网络环境下提出一种基于生命游戏的拥塞控制策略(game of life based congestion control strategy in delay tolerant networks,GLCCS),并将其应用于Epidemic路由方式.GLCCS借鉴生命游戏的演化思想,依据邻居节点中持有特定报文的节点比例来决定节点本地缓存中相应报文的操作.同时还提出了基于全网信息的报文排队机制和丢弃策略,依据传递或者丢弃一个报文对整个网络投递成功率的影响,计算出报文的效用值,按照效用值对缓存中报文进行排队和丢弃.在机会网络模拟器ONE中对仿真移动模型和真实运动轨迹进行模拟,实验结果表明,GLCCS与其他拥塞控制策略相比提高了投递成功率,减小了网络时延、丢包率以及负载比率.展开更多
基金Supported by National Natural Science Foundation of China(61911530398,12231012)Consultancy Project by the Chinese Academy of Engineering(2022-JB-06,2023-JB-12)+3 种基金the Natural Science Foundation of Fujian Province of China(2021J01621)Special Projects of the Central Government Guiding Local Science and Technology Development(2021L3018)Royal Society of Edinburgh(RSE1832)Engineering and Physical Sciences Research Council(EP/W522521/1).
文摘A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,the aging rates between two age groups are set to be constant.The existence-and-uniqueness of global positive solution is firstly showed.Then,by constructing several appropriate Lyapunov functions and using the high-dimensional Itô’s formula,the sufficient conditions for the stochastic extinction and stochastic persistence of the exposed individuals and the infected individuals are obtained.The stochastic extinction indicator and the stochastic persistence indicator are less-valued expressions compared with the basic reproduction number.Meanwhile,the main results of this study are modified into multi-age groups.Furthermore,by using the surveillance data for Fujian Provincial Center for Disease Control and Prevention,Fuzhou COVID-19 epidemic is chosen to carry out the numerical simulations,which show that the age group of the population plays the vital role when studying infectious diseases.
基金supported by the National Natural Science Foundation of China(60874114)
文摘Stochastic switched epidemic systems with a discrete or distributed time delay are constructed and investigated. By the Lyapunov method and lto＇s differential rule, the existence and uniqueness of global positive solution of each system is proved. And stability conditions of the disease-free equilibrium of the systems are obtained. Numerical simulations are presented to illustrate the results.
基金Supported by the National Natural Science Foundation of China(31201911 31372438)
文摘Porcine epidemic diarrhea(PED)is caused by porcine epidemic diarrhea virus(PEDV),and is characterized by vomiting,diarrhea and dehydration of suckling pigs from 80% to 100% morbidity and 50% to 90% mortality,and resulted in tremendous economic losses to swine industry.The PEDV mainly infects small intestine of pigs,resulting in vacuolar degeneration and necrosis of mucosal epithelium.The IPEC-J2 is a pig intestine epithelial cell line,which is similar to the intestinal environment of piglets,can be used to isolate and identify the PEDV field isolates.In this study,it appeared the PEDV typical postmortem changes and histopathological lesion of degeneration and destruction of small intestine in infected piglets,and IHC identified that the PEDV distributed in the mucosa and submucosa of small intestine mostly.Furthermore,the PEDV HLJ strain was successfully isolated and characterized in the IPEC-J2 cells,and indicated that the IPEC-J2 cell line was sensitive to isolate and adapt the PEDV field strain,and could be utilized to multiply the PEDV rapidly.The S gene analysis indicated that the PEDV HLJ strain was the prevailed virus,belonged to Group 1 with attenuated virulent DR13,SC1402 and J-S2/2015 strains isolated in South Korea and China from 2014 to 2015.This study had important theoretical and practical significances on analyzing genetic variation of the PEDV,understanding the pathogenic characteristics of the virus and developing new vaccines for the PED.
基金Supported by the National Natural Science Foundation of China(31370140,31372438)。
文摘The p65 protein is a functional subunit of NF-κB family and exhibits a crucial role in host immune and inflammatory responses,apoptosis and tumor proliferation if improperly-regulated.Given its ubiquitous association with nearly all the animal cells and its pleotropic functions,the gene encoding NF-κB p65 subunit was cloned and sequenced from porcine kidney(PK-15)cells.The gene was 1662 bp in length,encoded a 553-amino acid protein and contained the prototypical NF-κB functional domains.Real-time quantitative RT-PCR and Western blot were used to characterize the transcription and expression levels of the p65 in different pig tissues.The results indicated that the p65 gene and protein were both broadly expressed in pig tissues,but most highly expressed in the intestine-associated lymph nodes and the lungs.To localize the recombinant protein in intestinal porcine epithelial cells(IPEC-J2),the gene was subcloned into the vector pEGFP(pEGFP-p65).Using fluorescence microscopy,the protein was found confined to the cytoplasm in normal cells;however,during porcine epidemic diarrhea virus(PEDV)infection,mRNA and protein expression were significantly up-regulated and the protein exhibited an overt tendency for nuclear translocalization consistent with a regulatory role in antiviral innate immunity.
文摘为了应对容迟网络中拓扑结构剧烈变化、节点间连接频繁中断等问题,报文通常采用"存储—携带—转发"的方式进行传输:节点将报文存储在缓存中,携带报文直到遇到合适的机会才将报文转发给其他节点.因为缓存有限,这样的传输方式会使节点缓存溢出,导致拥塞的发生.在容迟网络环境下提出一种基于生命游戏的拥塞控制策略(game of life based congestion control strategy in delay tolerant networks,GLCCS),并将其应用于Epidemic路由方式.GLCCS借鉴生命游戏的演化思想,依据邻居节点中持有特定报文的节点比例来决定节点本地缓存中相应报文的操作.同时还提出了基于全网信息的报文排队机制和丢弃策略,依据传递或者丢弃一个报文对整个网络投递成功率的影响,计算出报文的效用值,按照效用值对缓存中报文进行排队和丢弃.在机会网络模拟器ONE中对仿真移动模型和真实运动轨迹进行模拟,实验结果表明,GLCCS与其他拥塞控制策略相比提高了投递成功率,减小了网络时延、丢包率以及负载比率.
