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11.
The objective of meat inspection is to promote animal and public health by preventing, detecting, and controlling hazards originating from animals. With the improvements of sanitary level in pig herds, the hazards profile has shifted and the inspection procedures no longer target major foodborne pathogens (i.e., not risk based). Additionally, carcass manipulations performed when searching for macroscopic lesions can lead to cross‐contamination. We therefore developed a stochastic model to quantitatively describe cross‐contamination when consecutive carcasses are submitted to classic inspection procedures. The microbial hazard used to illustrate the model was Salmonella, the data set was obtained from Brazilian slaughterhouses, and some simplifying assumptions were made. The model predicted that due to cross‐contamination during inspection, the prevalence of contaminated carcass surfaces increased from 1.2% to 95.7%, whereas the mean contamination on contaminated surfaces decreased from 1 logCFU/cm² to ?0.87 logCFU/cm², and the standard deviations decreased from 0.65 to 0.19. These results are explained by the fact that, due to carcass manipulations with hands, knives, and hooks, including the cutting of contaminated lymph nodes, Salmonella is transferred to previously uncontaminated carcasses, but in small quantities. These small quantities can easily go undetected during sampling. Sensitivity analyses gave insight into the model performance and showed that the touching and cutting of lymph nodes during inspection can be an important source of carcass contamination. The model can serve as a tool to support discussions on the modernization of pig carcass inspection.  相似文献   
12.
We used an agent‐based modeling (ABM) framework and developed a mathematical model to explain the complex dynamics of microbial persistence and spread within a food facility and to aid risk managers in identifying effective mitigation options. The model explicitly considered personal hygiene practices by food handlers as well as their activities and simulated a spatially explicit dynamic system representing complex interaction patterns among food handlers, facility environment, and foods. To demonstrate the utility of the model in a decision‐making context, we created a hypothetical case study and used it to compare different risk mitigation strategies for reducing contamination and spread of Listeria monocytogenes in a food facility. Model results indicated that areas with no direct contact with foods (e.g., loading dock and restroom) can serve as contamination niches and recontaminate areas that have direct contact with food products. Furthermore, food handlers’ behaviors, including, for example, hygiene and sanitation practices, can impact the persistence of microbial contamination in the facility environment and the spread of contamination to prepared foods. Using this case study, we also demonstrated benefits of an ABM framework for addressing food safety in a complex system in which emergent system‐level responses are predicted using a bottom‐up approach that observes individual agents (e.g., food handlers) and their behaviors. Our model can be applied to a wide variety of pathogens, food commodities, and activity patterns to evaluate efficacy of food‐safety management practices and quantify contamination reductions associated with proposed mitigation strategies in food facilities.  相似文献   
13.
针对反求工程中截面重构时由于分段点提取不精确造成重构结果不理想的问题,提出一种分段点精确提取方 法。基于截面数据的法向量信息构建高斯图,将分段点确定在一个区间内,根据区间端点将截面数据分为不同的特征 段;优先重构直线特征,再根据约束重构自由特征,并在自由特征重构过程中建立动态搜索模型,用二次插值法动态搜索 精确分段点。实验表明该方法提高了分段点的提取精度和截面重构的精度,重构的结果很好地还原了产品模型的初始 设计意图。  相似文献   
14.
《布鲁塞尔规则》2001年取代了《布鲁塞尔公约》,成为新的欧盟指令来规范相关的跨界国际私法的争议。欧盟委员会2004年针对适用《欧洲经济共同体条约》第81条的规定颁布了配套的指令TTBER和适用这个指令的指南。指令第3条规定了两个协议合作的企业市场份额门槛的认定标准,这个标准取代了过去的分类方法,在欧洲引起广泛的讨论。欧盟知识产权跨界禁令和竞争规则研究,突破了知识产权的地域性原则,完善了知识产权的竞争规则,并提供了相应的法律救济,有助于中国政府指导自己的企业与欧盟开展贸易。  相似文献   
15.
作为当代语义学的一种新范式,自然语义元语言理论于1972年由波兰语义学派创始人安娜·威尔兹彼卡提出.国内的自然语义元语言理论研究始于20世纪90年代初.1994-2014年,我国学者发表相关论文达五十余篇,出版专著两部,初步建构起一套独特的自然语义元语言理论研究体系.从NSM的本体研究、与其他语义学理论的比较、语义解释力、批判性评价、应用研究等五个方面回顾了20年来国内自然语义元语言理论研究的概况,指出了该领域研究中存在的不足,并对其发展前景进行了展望.  相似文献   
16.
在海明威的短篇小说中,《弗朗西斯·麦康伯短暂的幸福生活》的叙述艺术别具一格,具有极大的艺术魅力。就其叙述方式说,横断面写法、围绕主题选择时间切点、张弛有致的节奏、悬念丛生的结局,显示了海明威构思的精巧。就其描写方式说,神态描写、语言描写,特别是肖像描写、心理描写,显示了海明威描写的传神。这些精巧的构思与传神的描写构成了小说的结构艺术特色。  相似文献   
17.
针对大气污染呈现出的复合型、流动性和跨区域的特点,将地方政府在大气污染联合防治中的相互影响总结为“同向外部效应”和“部分排他效应”,应用演化博弈分析法,剖析地方政府之间大气污染联合防治的演化过程和演化结果。研究结果表明:地方政府治污成本的降低、对不治理污染地方政府惩罚力度的加大、地方政府治理大气污染效果的提高、地方政府不治理大气污染可见性的提升、大气污染治理外部性的减弱等都有助于演化博弈的稳定策略向地方政府跨区域联合防治的方向演进,从而有助于提升大气污染的治理效果,达到改善生态环境的目的。  相似文献   
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19.
The shared resource hypothesis suggests that married couples share the same environmental resources, which shape their health concordance. This study tests its cross‐national applicability. Cross‐sectional 2012–2013 Health and Retirement Study data from China, England, Mexico, and the United States were analyzed. Heterosexual couples (age ≥60) who were married or partnered were studied (N = 20,565 pairs). Dyadic data were analyzed by multilevel models to examine the effect of self and spousal social and physical health statuses on depressive symptoms. Regression models were used to test the relationship between couples' shared resources and depressive symptom concordance. Results indicated both husbands and wives' depressive symptoms were associated with their own and spouses' social and health statuses. Most couple‐level resources were insignificant predictors for Chinese and Mexican couples' concordance, but having more social and financial resources was associated with higher concordance among British and American couples. Self‐reported health was the most consistent predictor in all countries. The shared resource hypothesis was more applicable to depressive symptom concordance within couples in the United States and England, but not in China and Mexico. Couple‐centered intervention is suggested for clinical practice, and the spousal effect should be considered in policymaking.  相似文献   
20.
周芸  吴蕾 《学术探索》2009,(4):134-139
跨体式新闻语言是一种由不同语体标记相互渗透所形成的言语现象。特定社会的时代精神、文化心理、思维模式以及新闻记者的角色定位、受众的知识文化背景等语境因素,不但影响着跨体式新闻语言的生成,促使跨体式新闻语言生成某种特殊的修辞效果,而且还因该效果所呈现的风格色彩进一步影响到新闻报道语言风格的形成。  相似文献   
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