An overview of the Salmonella enteritidis risk assessment for shell eggs and egg products.

This article summarizes a quantitative microbial risk assessment designed to characterize the public health impact of consumption of shell eggs and egg products contaminated with Salmonella Enteritidis (SE). This risk assessment's objectives were to: (1) establish the baseline risk of foodborne illness from SE, (2) identify and evaluate potential risk mitigation strategies, and (3) identify data gaps related to future research efforts. The risk assessment model has five modules. The Egg Production module estimates the number of eggs produced that are SE-contaminated. Shell Egg Processing, Egg Products Processing, and Preparation & Consumption modules estimate the increase or decrease in the numbers of SE organisms in eggs or egg products as they pass through storage, transportation, processing, and preparation. A Public Health Outcomes module then calculates the incidence of illnesses and four clinical outcomes, as well as the cases of reactive arthritis associated with SE infection following consumption. The baseline model estimates an average production of 2.3 million SE-contaminated shell eggs/year of the estimated 69 billion produced annually and predicts an average of 661,633, human illnesses per year from consumption of these eggs. The model estimates approximately 94% of these cases recover without medical care, 5% visit a physician, an additional 0.5% are hospitalized, and 0.05% result in death. The contribution of SE from commercially pasteurized egg products was estimated to be negligible. Five mitigation scenarios were selected for comparison of their individual and combined effects on the number of human illnesses. Results suggest that mitigation in only one segment of the farm-to-table continuum will be less effective than several applied in different segments. Key data gaps and areas for future research include the epidemiology of SE on farms, the bacteriology of SE in eggs, human behavior in food handling and preparation, and human responses to SE exposure.     

河南学人与甲骨学研究

殷墟甲骨文被发现后 ,1 0 0年来已发展为一门国际“显学”。河南学人在甲骨文的发掘、整理、刊布、研究等方面都卓有成效 ,是甲骨学和殷商文化研究界的一支重要的学术力量。     

释"毛"、"舞"

先秦典籍中,“毛”字含义有三:毛发与兽毛之类;草类;五谷。金文和《说文》中的“毛”,字形像谷子。“毛”字的基本含义就是“五谷”。甲骨文中无“毛”字而有“舞”字,“舞”字中一人所执之物非一般所释的“牛尾”,而是倒执的“毛”,即五谷。“舞”是古人在谷物成熟后执禾而舞。     

用于陆地工业的增压锅炉设计改进

增压锅炉节能环保的优点使其具有良好的陆地工业应用前景。针对制造成本和技术要求高的缺点,提出使用罗 茨风机代替附加汽轮机的工作方案;改用锅壳式布置形式,降低增压锅炉炉膛出口烟温。研究结果表明以上改进措施可 以大幅降低增压锅炉生产成本,提高锅炉的承压及密封效果,解决耐高温材料限制。     

Consumer-Phase Salmonella enterica serovar Enteritidis Risk Assessment for Egg-Containing Food Products

We describe a one-dimensional probabilistic model of the role of domestic food handling behaviors on salmonellosis risk associated with the consumption of eggs and egg-containing foods. Six categories of egg-containing foods were defined based on the amount of egg contained in the food, whether eggs are pooled, and the degree of cooking practiced by consumers. We used bootstrap simulation to quantify uncertainty in risk estimates due to sampling error, and sensitivity analysis to identify key sources of variability and uncertainty in the model. Because of typical model characteristics such as nonlinearity, interaction between inputs, thresholds, and saturation points, Sobol's method, a novel sensitivity analysis approach, was used to identify key sources of variability. Based on the mean probability of illness, examples of foods from the food categories ranked from most to least risk of illness were: (1) home-made salad dressings/ice cream; (2) fried eggs/boiled eggs; (3) omelettes; and (4) baked foods/breads. For food categories that may include uncooked eggs (e.g., home-made salad dressings/ice cream), consumer handling conditions such as storage time and temperature after food preparation were the key sources of variability. In contrast, for food categories associated with undercooked eggs (e.g., fried/soft-boiled eggs), the initial level of Salmonella contamination and the log10 reduction due to cooking were the key sources of variability. Important sources of uncertainty varied with both the risk percentile and the food category under consideration. This work adds to previous risk assessments focused on egg production and storage practices, and provides a science-based approach to inform consumer risk communications regarding safe egg handling practices.     

固体火箭发动机壳体的模态分析

不稳定燃烧是固体火箭发动机的一种不正常的工作状态,这种不稳定燃烧可使燃烧室压强振荡的振幅达到相当大的量级,使发动机产生强烈的振动,可能使燃烧室壳体或推进剂装药受到破坏,从而引起发动机爆炸.利用大型有限元分析软件AN SY S对固体火箭发动机壳体进行了模态分析,并获得了对其强度和性能影响强烈的频率,此结果对研究固体火箭发动机的动力学特性及不稳定燃烧进行了理论分析、预测和防止压强发生振荡具有重要作用.     

静水压力对加筋壳体振动特性的影响

采用Ｆｌｕｇｇｅ’ｓ壳体理论，对两端简支环加筋壳体在静水压力作用下的振动特性进行了研究，分析了静水压力及其变化对加筋壳体振动特性的影响，探讨了内压、外压及轴向压力对环加筋壳体固有频率的影响．     

基于语料库的搭配和类联接研究——以回指概念外壳名词为例

搭配是语言中横组合关系的词项间的习惯性共现,类联接是比搭配更高一级的词汇与语法之间的共现关系。对英语中搭配和类连接的研究不应局限于短语或小甸,而应扩展到语篇层面。文章以回指概念外壳名词为例,进行基于语料库的与语篇功能相连的搭配和类连接的研究。结果显示,外壳名词在评价力的强度、类连接构式的倾向性、对前置修饰语的依赖度、语篇类型的敏感度方面都存在诸多差异。     

Expert Edge

No abstract available for this article.     

均衡型城市化：中国城市化的发展方向

通过对＂均衡型城市化＂概念的界定及其主要特征和表现形式的简析,得知：中国城市化的＂非均衡态＂凸显、城市病潮的涌现以及农村＂空壳化＂问题的显露成为实现＂均衡型城市化＂的现实成因。基于这些成因的分析,在城市化进程中以及城市化模式抉择的形势下,实现城市的网络化、找寻最佳城市规模、实行农村＂就地城市化＂,以及优化产业空间、促进产业升级成为城市化由＂非均衡＂模式转向＂均衡＂模式的有效举措。