U.K. Foot and Mouth Disease: A Systemic Risk Assessment of Existing Controls

This article details a systemic analysis of the controls in place and possible interventions available to further reduce the risk of a foot and mouth disease (FMD) outbreak in the United Kingdom. Using a research‐based network analysis tool, we identify vulnerabilities within the multibarrier control system and their corresponding critical control points (CCPs). CCPs represent opportunities for active intervention that produce the greatest improvement to United Kingdom's resilience to future FMD outbreaks. Using an adapted ‘features, events, and processes’ (FEPs) methodology and network analysis, our results suggest that movements of animals and goods associated with legal activities significantly influence the system's behavior due to their higher frequency and ability to combine and create scenarios of exposure similar in origin to the U.K. FMD outbreaks of 1967/8 and 2001. The systemic risk assessment highlights areas outside of disease control that are relevant to disease spread. Further, it proves to be a powerful tool for demonstrating the need for implementing disease controls that have not previously been part of the system.     

绝经后女性冠心病患者性激素改变与血脂水平的研究

目的探讨绝经后女性冠心病(CHD)患者性激素水平的变化及与血脂的关系.方法对30例绝经后女性CHD患者和30例绝经后女性正常对照者的血清总胆固醇(TC)、甘油三脂(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、雌二醇(E2)、孕酮(P)、睾酮(T)、卵泡刺激素(FSH)、促黄体生成素(LH)进行了检测.结果两组间年龄、绝经年数差异无显著性.绝经后女性CHD患者较正常对照组的E2、E/T、HDL-C明显降低(P＜0.001、P=0.002、P=0.001),TC、TG、LDL-C增高(P=0.027、P=0.041、P＜0.001),两组T、P无显著性差异(P＞0.05).相关分析表明绝经后女性CHD患者的E2与TC、TG、LDL-C均呈显著负相关,与HDL-C呈显著正相关.E/T与TC、TG亦呈显著负相关.结论绝经后女性CHD患者血脂异常与雌激素水平明显降低有关,它们共同参与绝经后女性CHD的发生和发展.     

Optimal design of experimental epidemics

We consider the optimal design of controlled experimental epidemics or transmission experiments, whose purpose is to inform the practitioner about disease transmission and recovery rates. Our methodology employs Gaussian diffusion approximations, applicable to epidemics that can be modeled as density-dependent Markov processes and involving relatively large numbers of organisms. We focus on finding (i) the optimal times at which to collect data about the state of the system for a small number of discrete observations, (ii) the optimal numbers of susceptible and infective individuals to begin an experiment with, and (iii) the optimal number of replicate epidemics to use. We adopt the popular D-optimality criterion as providing an appropriate objective function for designing our experiments, since this leads to estimates with maximum precision, subject to valid assumptions about parameter values. We demonstrate the broad applicability of our methodology using a diverse array of compartmental epidemic models: a time-homogeneous SIS epidemic, a time-inhomogeneous SI epidemic with exponentially decreasing transmission rates and a partially observed SIR epidemic where the infectious period for an individual has a gamma distribution.     

Models for residual time to AIDS

The distributions of the time from Human Immunodeficiency Virus (HIV) infection to the onset of Acquired Immune Deficiency Syndrome (AIDS) and of the residual time to AIDS diagnosis are important for modeling the growth of the AIDS epidemic and for predicting onset of the disease in an individual. Markers such as CD4 counts carry valuable information about disease progression and therefore about the two survival distributions. Building on the framework set out by Jewell and Kalbfleisch (1992), we study these two survival distributions based on stochastic models for the marker process (X(t)) and a marker-dependent hazard (h()). We examine various plausible CD4 marker processes and marker-dependent hazard functions for AIDS proposed in recent literature. For a random effects plus Brownian motion marker process X(t)=(a+bt+BM(t))⁴, where a has a normal distribution, b<0 is an unknown parameter and BM(t) is Brownian motion, and marker-dependent hazard h(X(t)), we prove that, given CD4 cell count X(t), the residual time to AIDS distribution does not depend on the time since infection t. Using simulation and numerical integration, we find the marginal incubation period distribution, the marginal hazard and the residual time distribution for several combinations of marker processes and marker-dependent hazards. An example using data from the Multicenter AIDS Cohort Study is given. A simple regression model relating the cube root of residual time to AIDS to CD4 count is suggested.     

生殖健康面临的严峻挑战：全球艾滋病形势综述

严重影响人类生殖健康的艾滋病正以前所未有的速度在全世界流行．从发现第一例病人至今不足20年时间里,绝大多数国家都已经报告发现了艾滋病病毒感染者．怎样进一步防治艾滋病已是各国政府、民间组织和科学工作者共同关注的焦点．     

敦煌书仪《问疾书》的语言表现

本文以敦煌书仪《问疾书》为研究对象，对其在语言上的表现作了考察。通过考察发现，《问疾书》中所使用的语言，在待遇表现上，是本着谦自己、赞他人的原则；在类似表现中不仅有直接表现，也有委婉表现。此外，尚罗列了一些在词典中没有收录的词汇。     

鱼病的初步诊断方法

渔业生产上常常需要通过肉眼来检查诊断鱼病 ,本文全面介绍了“鱼、病原体、养鱼环境”的“观察、检查、调查、综合分析”等科学诊断方法 ,以及常见鱼病的症状参考表 ,为渔业生产者提供技术信息。     

一例急性败血性猪丹毒爆发的诊断

１９９９年４月在四川省某区的架子猪陆续发病，经过流行病学调查、病原分离、鉴定，诊断为猪丹毒。药敏试验结果表明氨苄青霉素和头孢哌酮敏感。     

禽流感疫病控制博弈模型与中央政府宏观调控模式选择

禽流感疫病控制博弈是完美但不完全信息非合作动态三方博弈。根据中央政府可能采取的(扑杀、强制免疫、扑杀和强制免疫)三种防控策略和中央政府(全额补偿、中央政府加地方政府不同比例全额补偿、中央政府加地方政府加个人不同比例补偿、中央政府加个人不同比例补偿、个人全额补偿)五种补偿政策,组合成十五种宏观调控模式。采用得益矩阵和均衡分析不难发现,中央政府最佳的宏观调控模式是中央政府采用(扑杀加强制免疫)防控策略和(中央政府加个人不同比例补偿)的补偿政策相结合的调控模式。