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.     

质量、信息和公共政策:消费者购买无公害鸡蛋的影响因素分析

本文以在北京市海淀区进行的消费者访谈和问卷调查,分析了消费者收入,消费者对产品的信任程度、消费者个体特征、无公害鸡蛋和普通鸡蛋的价格差等对消费者鸡蛋购买行为的影响。基于数量化理论Ⅱ类的模型估计结果表明,消费者的收入水平、对无公害鸡蛋的相信程度以及性别是影响消费者购买无公害和绿色鸡蛋的主要因素,而年龄和不同地点无公害鸡蛋与普通鸡蛋的价格差对消费者购买行为的影响比较复杂,教育程度对购买行为的影响较小,但其影响方向与理论预期一致。根据实证结论,最后提出了提高中低收入者的收入水平、通过政府监控宣传和生产者的自律提高消费者对无公害食品的信任程度、以及将无公害鸡蛋价格的合理设定等政策含义和商业启示。     

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.     

纸膜成型无铅松花蛋的研制

在松花蛋形成原理基础上 ,利用有效的辅助材料和纸膜技术 ,经过配方筛选 ,对纸膜加工松花蛋的碱液的浓度、形成时间、感官指标等方面进行试验探索 ,为工厂化生产提供依据。     

鲤鱼胚胎冷却至-196℃的试验

鱼类胚胎的低温保存是世界范围内尚未解决的课题,在对鲤鱼胚胎低温保存的初步试验中,我们发现在溶液冰点至-60℃范围内,降温速率对胚胎存活率来说是个决定性因素。如降温速率大于0.5℃/min,胚胎很难存活,而最佳降温速率应小于0.07℃/min,对于鱼类胚胎保存而言,慢复温是比较合适的。在我们的试验研究中,若以2.0mol/LDMSO为抗冻剂,降温速率为0.07℃/min,复温速率为8℃/min时,兴国紅鲤尾芽期胚胎经降温至液氮温度(-196℃),并保存一段时间后复温,仍能存活并孵化为幼鱼。试验达到的最大存活率为25%,出苗率为18%。     

A Risk-Benefit Analysis of French High Fish Consumption: A QALY Approach

The health risk and the nutritional benefit of a food are usually assessed separately. Toxicologists recommend limiting the consumption of certain fish because of methylmercury; while nutritionists recommend eating more oily fish because of omega 3. A common evaluation is imperative to provide coherent recommendations. In order to evaluate the risks along with the benefits related to fish consumption, a common metric based on the quality-adjusted life year (QALY) method has been used. The impact of a theoretical change from a medium n-3 PUFAs intake to a high intake is studied, in terms of the cardiovascular system (CHD mortality, stroke mortality and morbidity) and on fetal neuronal development (IQ loss or gain). This application can be considered as a sensitive analysis of the model used and looks at the impact of changing the dose-response relationships between cardiovascular diseases and n-3 PUFAs intakes. Results show that increasing fish consumption may have a beneficial impact on health. However, the confidence interval of the overall estimation has a negative lower bound, which means that this increase in fish consumption may have a negative impact due to MeHg contamination. Some limits of the QALY approach are identified. The first concerns determination of the dose-response relationships. The second concerns the economic origins of the approach and of individual preferences. Finally, since only one beneficial aspect and one risk element were studied, consideration should be given to how other beneficial and risk components may be integrated in the model.     

精神生态批评视域下的《沉没之鱼》

生态批评历来是文学批评的一个热点视角,作为其一个分支,精神生态批评近年来也引发了越来越多的关注。谭恩美的小说《沉没之鱼》中,旅行团一行十二名游客,每人身上都带有现代文明人精神生态失衡的各种症状。他们通过东方之旅,在不断亲近、深入原生态自然的过程中,逐渐寻回本真的自我,治愈了各种现代病。东方之旅是一次人与自然的和解之旅,一次现代人的自我疗伤之旅。     

《拯救溺水鱼》的空间重构

谭恩美的小说《拯救溺水鱼》是一部另类作品,将作品纳入到布里尔·佐伦的空间叙事框架的考量中,是一种新的探索与尝试。谭恩美以独到的笔法建构出作品的地志空间、时空体空间、文本空间：空间旅行的表层环形结构与内嵌的标志性“亚空间”单位构建多层次空间图像,实现主题观照;“幽灵”叙事,虚实辗转,营构时空体;文本设置中的情节并置、闪回、碎片独白打破时序园囿,突破读者感知限制,创设文本重构空间。这些特点充分展示了作者的空间书写策略,体现了谭恩美对传统写作的超越与独特的文学追求。     

斯坦利·费什的阅读观与女性主义文本

当代女性主义写作由于强调自我和身体感受,招来历史维度和道德维度的批评,作品社会功能的实现受到了阻碍。斯坦利.费什的读者反应理论有助于解释女性作品遭遇男性读者抵制接受的原因,因此女性创作应该坚持"和而不同"的对话原则,而非一味排斥作为"他者"的男性。     

Non-linear state space modelling of fisheries biomass dynamics by using Metropolis-Hastings within-Gibbs sampling

State space modelling and Bayesian analysis are both active areas of applied research in fisheries stock assessment. Combining these two methodologies facilitates the fitting of state space models that may be non-linear and have non-normal errors, and hence it is particularly useful for modelling fisheries dynamics. Here, this approach is demonstrated by fitting a non-linear surplus production model to data on South Atlantic albacore tuna ( Thunnus alalunga ). The state space approach allows for random variability in both the data (the measurement of relative biomass) and in annual biomass dynamics of the tuna stock. Sampling from the joint posterior distribution of the unobservables was achieved by using Metropolis-Hastings within-Gibbs sampling.