Simulation of the spread of infectious diseases in a geographical environment

The study of mathematical models for the spread of infectious diseases is an important issue in epidemiology. Given the fact that most existing models cannot comprehensively depict heterogeneities (e.g., the population heterogeneity and the distribution heterogeneity) and complex contagion patterns (which are mostly caused by the human interaction induced by modern transportation) in the real world, a theoretical model of the spread of infectious diseases is proposed. It employs geo-entity based cellular automata to simulate the spread of infectious diseases in a geographical environment. In the model, physical geographical regions are defined as cells. The population within each cell is divided into three classes: Susceptible, Infective, and Recovered, which are further divided into some subclasses by states of individuals. The transition rules, which determine the changes of proportions of those subclasses and reciprocal transformation formulas among them, are provided. Through defining suitable spatial weighting functions, the model is applied to simulate the spread of the infectious diseases with not only local contagion but also global contagion. With some cases of simulation, it has been shown that the results are reasonably consistent with the spread of infectious diseases in the real world. The model is supposed to model dynamics of infectious diseases on complex networks, which is nearly impossible to be achieved with differential equations because of the complexity of the problem. The cases of simulation also demonstrate that efforts of all kinds of interventions can be visualized and explored, and then the model is able to provide decision-making support for prevention and control of infectious diseases. Supported by Postdoctoral Foundation of China (Grant No. 20070410552) and Youth Fund of Institute of Policy and Management (IPM), the Chinese Academy of Sciences (Grant No. O700481Q01)     

热带海洋珍珠贝类立克次体病研究 Ⅳ.组织细胞病理学研究

类立克次体（RLO）对大珠母贝和合浦珠母贝具有强烈的致病性,引起基本一致的病理变化．在急性坏死破坏期内,RLO导致外套膜、鳃、消化管、肝胰腺、生殖腺腺管及全身血管内皮系统等多器官组织的变性坏死,使器官组织结构的完整性遭到破坏,破坏程度与RLO包涵体的数目密切相关,而细胞的破坏与细胞内RLO的生长发育及繁殖到大量数目密切相关．鉴于此,将RLO引起的珍珠贝病称为类立克次体病（RLO病）．RLO病呈急性变质性炎症和慢性增生性炎症病理,在前者细胞呈现崩解性坏死、溶解性坏死和退变性坏死;在后者存在实质细胞增生和纤维母细胞增生为纤维细胞并形成纤维化．根据炎症病理的发展过程,RLO病可分为急性坏死破坏期和慢性增生修复期．     

对虾组织蛋白质和同工酶表型及其在病虾中的变化

利用ＳＤＳ－聚丙烯酰胺凝胶电泳和非变性聚丙烯酰胺凝胶龟泳对中国对虾四和中组织的蛋白质、酯酶、乳酸脱氢酶和超氧化物歧化酶等同工酶进行了分析研究，并将健康虾与流行病病虾进行了比较。结果表明，肝胰脏和肌肉组织的蛋白质表型、肝胰脏酯酶和超氧化物歧化酶的表型在健康虾和病虾之间存在着较明显的差异。说明肝胰脏内蛋白质代谢有明显的紊乱现象。肝胰脏和肌肉的组织蛋白、肝酯酶和超氧化物歧化酶的特异性变化，可作为虾病早期     

导致热带产卡拉胶海藻大规模死亡原因分析与藻株抗病差异性比较

2008年夏季东南亚地区栽培的产卡拉胶海藻麒麟菜类陆续发生冰样白化病害并造成大规模死亡.本文根据作者近年来的观测和实验数据探讨了产生该现象的环境因素,通过重演性实验验证和比较了不同株系抗病力差异.结果表明:1)不同海菜株系的抗病能力差异很大,从印度尼西亚引进株系比从菲律宾引进株系抗病能力强,其中株系5抗病能力最强,没有发生冰样白化病症:株系4、6和11的抗病能力次之,只在10%以下的藻株出现病害症状,日生长速率在7%以上的高水平:株系7、8和9号病害损伤程度是印度尼西亚引进株系中最为严重的,但比原产菲律宾海菜要轻.2)与往年同期气象数据相比,在病害发生期间光照时间短、强度弱、海水温度高、降雨量多、蒸发量少、海水盐度下降,上述变化明显不能满足热带产胶海藻生长所需要环境条件,导致了海菜生理状况和生长速率下降.3)从海湾内海菜发病分布和死亡程度上,越远离海湾口和偏离主航道、水浅流速小区域所栽培的海菜发病越早、死亡也越严重;相反,在靠近湾口与外海具有较好水交换和离航道近、水深流速大的区域,海菜发病相对较晚.4)重演实验证实,将海菜浸泡在盐度28的海水中2h,1天后部分株系就会出现冰样白化病症,3天后藻体软化而死亡;海菜浸泡在22盐度的海水2h,会导致更多株系的海菜发生严重的白化病害并死亡.上述结果表明,过多降雨所导致的海水盐度下降是诱发热带产胶海藻爆发大面积病害发生和死亡的主要原因.     

以斑马鱼为疾病模型的小分子药物筛选研究进展

斑马鱼具有体积小,产卵量多,发育迅速,胚胎透明等特点,目前已成为一种非常重要的发育生物学模式动物。同时,斑马鱼胚胎体外发育,小分子化合物渗透性强,这些优势使其成为大规模小分子药物筛选的理想模型。近年来,随着以CRISPR/Cas9为代表的基因编辑技术的兴起,大量的转基因斑马鱼和突变体被构建出来,成为模拟人类疾病的良好模型,这些模型被广泛应用于药物筛选的多个方面。利用斑马鱼进行药物筛选,不仅具备高通量、低成本的优点,还能够比较准确的评估药物效果以及药物毒性。本文主要介绍了斑马鱼的特点以及其作为疾病模型在药物筛选中的应用,旨在帮助人们了解斑马鱼药物筛选的研究进展以及阐明斑马鱼在新药研发中的优势。     

Studies on pathogen of explosive epidemic disease of shrimp Ⅱ.Purification of pathogen

ThisworkisfundedbyagrantfromtheNationalKeyTaskProjectsof8thand9thFive-yearplanprogram.INTRODUCTIONInthepastyears,studiesonthevirusesofpenaeidshrimpshavemadegreatprogressinvari-ouscountries.Rightnow,aboutl4virusesofpenaeidshrimpswerefound,i.e.BP(Baculoviruspenaei,Couch,1974),MBV(Penaeusmonndonbaculovirus,Lightneretal.,1983)orPBV(Penaeusplebejusbaculovirus,Lesteretal.,1987),BMN(Baculovirusmidgutglandnecrosisvirus,Sanaetal.,1981),PHRV(Penaeushybridrod-shapedvirus,Owensetal.,199l),…     

螺旋藻(Spirulina)对慢性肝损伤小鼠肝组织抗氧化能力的影响

用四氯化碳导致小鼠肝损伤,各组每日灌胃不同剂量螺旋藻,检测了饲养45d的小鼠血清的ALT活力、肝组织的SOD活力和MDA含量,分别建立ALT、SOD活力以及MDA含量随剂量(C)变化的函数,求出各项临界参数值,并对参数的生物学意义进行解释,以观察螺旋藻对肝损伤小鼠肝组织中SOD活力和MDA的影响.实验结果显示:螺旋藻能提高小鼠SOD的活力并降低其MDA含量,进一步验证了螺旋藻可提高肝损伤小鼠肝组织的抗氧化能力,分析结果还显示螺旋藻对肝组织抗氧化能力的提高既具有一定的量效累积性,也存在量效局限性.     

Effect of Short-term Forest Bathing in Urban Parks on Perceived Anxiety of Young-adults: A Pilot Study in Guiyang,Southwest China

Forest can be taken as a natural therapy to alleviate perceived anxiety of visitors. Given the geographical difference between urban and rural forest environments, little is known about the urban forest therapy effect of anxiety alleviation with reference to the rural forest. In this study, forty-three university students(aged from 19 to 23) were recruited as participants to visit the forest parks at urban and rural areas of Guiyang City on 21 and 23 December 2016. The forest experience was separated by four sceneries. Participants were asked to complete questionnaires by self-evaluating specific anxiety change from 12 questions with scores from 1 to 10 at both entrance and exit of the parks. The Wilcoxon signed-rank test and paired t-test were used to compare the change of anti-anxiety scores during forest bathing and between urban and rural forests, respectively. Results revealed that forest bathing in the urban park can alleviate the anxiety from financial state(P = 0.0028), exam-pass pressure(P = 0.0040) and love-affair relationship(P = 0.0286). Although rural forest bathing can also alleviate the anxiety from financial state(P = 0.0222), meanwhile, it maintained the anxiety about campus life(P < 0.0001). Forest tree richness tended to be higher in the rural forest park than in the urban one, which in contrast decreased the anxiety alleviation from inter-communication in the rural forest park(P = 0.0487). Principle component analysis indicated that participants tended to perceive more decline of anxiety from social contact in the urban forest. In conclusion, university students were recommended to pay a short visit to the urban forest with partners if they felt anxious about personal affairs and felt necessary to talk with others. For general people's visiting, urban forest trees can be controlled in diversity to some extent to look orderly and alleviate perceived anxiety.     

基于信息熵的中国自然疫源性疾病分布特征研究

中国目前发现有43种自然疫源性疾病,其中鼠疫、人禽流感、疟疾、登革热等14种被列为国家法定传染病,对中国人民生命健康造成了很大的威胁。为了探讨中国自然疫源性疾病发病数量均衡/不均衡的区域分布规律,本文运用Shannon信息熵理论和空间自相关方法,基于2004-2015年14种自然疫源性疾病的发病数,对中国自然疫源性疾病进行了分析。研究结果表明：① 中国自然疫源性疾病发病数量均衡/不均衡的区域在空间上具有明显的西北-东南分异特征,并具有显著的空间自相关关系,高值聚集区和低值聚集区主要分布在以河北-云南连线上山脉分界线的两侧;② 自然因素是影响自然疫源性疾病发病均衡程度的主要因素,在温暖潮湿（即温度适宜、水分充足）的地区更容易发生多种疾病,疾病发病数量相近;在特定牲畜为主或特定蚊虫流行地区更容易发生单种疾病,疾病发病数量不均衡;③ 我国发病总数高的区域往往是因为单种疾病极其严重导致,而信息熵高的地区往往存在多种疾病发生,这两类地区在自然疫源性疾病防治上,需要根据地区特点采取不同措施。     

酵母培养物替代鱼粉对凡纳滨对虾生长性能、血清生化指标、免疫力和抗病力的影响

【目的】探讨高蛋白酵母培养物替代鱼粉对凡纳滨对虾(Litopenaeusvannamei)生长性能、血清生化指标、非特异性免疫力和抗病力的影响。【方法】在基础饲料中分别添加质量分数0、2.5%、5.0%和7.5%酵母培养物(记为Y0、Y2.5、Y5.0和Y7.5组),分别替代质量分数0、10%、20%和30%的鱼粉,配制4种等氮等脂饲料,饲喂凡纳滨对虾(初始体质量0.70±0.03 g)56 d后,测定对虾生长性能、血清生化及免疫酶指标;用哈维氏弧菌(Vibrioharveyi)攻毒,测定对虾累计死亡率。【结果】Y2.5和Y5.0组凡纳滨对虾增重率和特定生长率与Y0组的差异无统计学意义(P> 0.05),Y5.0组凡纳滨对虾摄食率显著高于Y0和Y2.5组(P <0.05);Y5.0组凡纳滨对虾血清甘油三酯含量显著低于Y0组(P<0.05),Y7.5组凡纳滨对虾血清谷丙转氨酶含量显著高于Y0、Y2.5组(P <0.05),血清总胆固醇显著低于Y0、Y2.5组(P <0.05);酵母培养物替代饲料中20%和30%的鱼粉可显著提高对虾攻毒前肝胰腺超氧化物歧化酶、过氧化物酶活性(P <0.05),Y7.5组对虾肝胰腺丙二醛含量在哈维氏弧菌(Vibrio harveyi)攻毒后显著低于Y0组(P <0.05);攻毒7 d后,Y7.5组凡纳滨对虾累积死亡率显著低于Y0组(P<0.05)。【结论】酵母培养物替代鱼粉比例小于20%时,不会显著影响凡纳滨对虾生长性能;替代比例为30%时,生长受抑制。当替代量比例为30%时可显著提高凡纳滨对虾非特异性免疫力和抗病力。