中西方道德教育在建筑之窗“眼”中的镜像

本文从中西建筑窗式的异同和功用出发,分析了中西方在对各自文化精神的传播以及道德教育环境营造上的意图和匠心,阐释了中西方高度一致地均将窗"眼"的视觉延伸至道德教化、指点迷津的精神层面,这对于我国当前社会的"道德滑坡"现象具有积极的现实意义。     

The Economic Efficiency of Sampling Size: The Case of Beef Trim Revisited

A recent paper by Ferrier and Buzby provides a framework for selecting the sample size when testing a lot of beef trim for Escherichia coli O157:H7 that equates the averted costs of recalls and health damages from contaminated meats sold to consumers with the increased costs of testing while allowing for uncertainty about the underlying prevalence of contamination. Ferrier and Buzby conclude that the optimal sample size is larger than the current sample size. However, Ferrier and Buzby's optimization model has a number of errors, and their simulations failed to consider available evidence about the likelihood of the scenarios explored under the model. After correctly modeling microbial prevalence as dependent on portion size and selecting model inputs based on available evidence, the model suggests that the optimal sample size is zero under most plausible scenarios. It does not follow, however, that sampling beef trim for E. coli O157:H7, or food safety sampling more generally, should be abandoned. Sampling is not generally cost effective as a direct consumer safety control measure due to the extremely large sample sizes required to provide a high degree of confidence of detecting very low acceptable defect levels. Food safety verification sampling creates economic incentives for food producing firms to develop, implement, and maintain effective control measures that limit the probability and degree of noncompliance with regulatory limits or private contract specifications.     

Impact of Microbial Ecology of Meat and Poultry Products on Predictions from Exposure Assessment Scenarios for Refrigerated Storage

A novel extension of traditional growth models for exposure assessment of food-borne microbial pathogens was developed to address the complex interactions of competing microbial populations in foods. Scenarios were designed for baseline refrigeration and mild abuse of servings of chicken broiler and ground beef Our approach employed high-quality data for microbiology of foods at production, refrigerated storage temperatures, and growth kinetics of microbial populations in culture media. Simple parallel models were developed for exponential growth of multiple pathogens and the abundant and ubiquitous nonpathogenic indigenous microbiota. Monte Carlo simulations were run for unconstrained growth and growth with the density-dependent constraint based on the "Jameson effect," inhibition of pathogen growth when the indigenous microbiota reached 10(9) counts per serving. The modes for unconstrained growth of the indigenous microbiota were 10(8), 10(10), and 10(11) counts per serving for chicken broilers, and 10(7), 10(9) and 10(11) counts per serving for ground beef at respective sites for backroom, meat case, and home refrigeration. Contamination rates and likelihoods of reaching temperatures supporting growth of the pathogens in the baseline refrigeration scenario were rare events. The unconstrained exponential growth models appeared to overestimate L. monocytogenes growth maxima for the baseline refrigeration scenario by 1500-7233% (10(6)-10(7) counts/serving) when the inhibitory effects of the indigenous microbiota are ignored. The extreme tails of the distributions for the constrained models appeared to overestimate growth maxima 110% (10(4)-10(5) counts/serving) for Salmonella spp. and 108% (6 x 10(3) counts/serving) for E. coli O157:H7 relative to the extremes of the unconstrained models. The approach of incorporating parallel models for pathogens and the indigenous microbiota into exposure assessment modeling motivates the design of validation studies to test the modeling assumptions, consistent with the analytical-deliberative process of risk analysis.     

"三个代表"思想之本

毛泽东在中国共产党第七次代表大会上第一次向世人宣布了中国共产党的"三大作风",并将全心全意为人民服务,一切从人民的利益出发,总结为"三大作风"的核心.57年后的今天,江泽民在庆祝中国共产党成立八十周年的"七一"讲话中,提出"三个代表"思想.继续强调始终代表最广大人民的根本利益,是中国共产党战胜各种困难和风险、不断取得事业成功的根本保证.     

新疆兵团农七师垦区绿洲农业经济发展研究

新疆兵团农七师垦区应抓住西部大开发契机,认清当前绿洲农业的现状,明确其今后发展方向,在充分发挥绿洲农业优势的基础上进行产业结构的战略调整,在专业化的基础上适度综合发展,实现农业经济的协调、稳定、快速发展。     

A Mathematical Model for Pathogen Cross‐Contamination Dynamics during the Postharvest Processing of Leafy Greens

We developed a probabilistic mathematical model for the postharvest processing of leafy greens focusing on Escherichia coli O157:H7 contamination of fresh‐cut romaine lettuce as the case study. Our model can (i) support the investigation of cross‐contamination scenarios, and (ii) evaluate and compare different risk mitigation options. We used an agent‐based modeling framework to predict the pathogen prevalence and levels in bags of fresh‐cut lettuce and quantify spread of E. coli O157:H7 from contaminated lettuce to surface areas of processing equipment. Using an unbalanced factorial design, we were able to propagate combinations of random values assigned to model inputs through different processing steps and ranked statistically significant inputs with respect to their impacts on selected model outputs. Results indicated that whether contamination originated on incoming lettuce heads or on the surface areas of processing equipment, pathogen prevalence among bags of fresh‐cut lettuce and batches was most significantly impacted by the level of free chlorine in the flume tank and frequency of replacing the wash water inside the tank. Pathogen levels in bags of fresh‐cut lettuce were most significantly influenced by the initial levels of contamination on incoming lettuce heads or surface areas of processing equipment. The influence of surface contamination on pathogen prevalence or levels in fresh‐cut bags depended on the location of that surface relative to the flume tank. This study demonstrates that developing a flexible yet mathematically rigorous modeling tool, a “virtual laboratory,” can provide valuable insights into the effectiveness of individual and combined risk mitigation options.     

七七事变前后抗日救亡运动特点之比较

抗日救亡运动与整个抗日战争相始终,并因政局和战局的变化呈现出明显的阶段性和阶段性特点.从运动的行为方式来看,七七事变前多属于民众自发行为或政党行为;而七七事变后则转变为被国民政府认可、参与的政府行为.从运动的形式和规模来看,七七事变前的多为请愿、示威等具有相当规模的个体活动;七七事变以后则发展为具有很大规模的整体运动.从运动的作用来看,七七事变前的抗日救亡运动有力地打击了国民党和国民政府的不抵抗政策,敦促其对日政策的调整和改变,驱使其最终走上抗战的道路;七七事变后的抗日救亡运动则坚定了国民政府的抗战信心,动员和激励了全国军民的抗战热情和胜利信念.     

The experience of the EEC Eurolink Project in modeling bilateral trade linkage equations

Following the basic philosophical approach of the LINK Project, which links various national econometric models built in different countries, the Commission of the European Communities has succeeded in linking the full-size quarterly econometric models of the four major European countries. The Eurolink Project is being extended to cover the other EEC countries as well as the United States, Canada, and Japan. The results reported in this paper are part of this larger project which attempts to link the EEC member economies in a trade and capital flows econometric model and explain the transmission of interdependent economic fluctuations from country to country. In the present study, the interconnection between the various economies is represented by bilateral trade flows only. Flows of invisibles and of financial capital are not completely studied and are not yet ready to be included in this report.The theoretical structural model with its bilateral trade supply and demand functions and the technique employed for the construction of bilateral import and export price indices are presented. Estimation results are shown and discussed with emphasis on their use for the analysis of international trade and for policy decision making.     

Smooth Estimation of the Reliability Function

Problems with censored data arise quite frequently in reliability applications. Estimation of the reliability function is usually of concern. Reliability function estimators proposed by Kaplan and Meier (1958), Breslow (1972), are generally used when dealing with censored data. These estimators have the known properties of being asymptotically unbiased, uniformly strongly consistent, and weakly convergent to the same Gaussian process, when properly normalized. We study the properties of the smoothed Kaplan-Meier estimator with a suitable kernel function in this paper. The smooth estimator is compared with the Kaplan-Meier and Breslow estimators for large sample sizes giving an exact expression for an appropriately normalized difference of the mean square error (MSE) of the two estimators. This quantifies the deficiency of the Kaplan-Meier estimator in comparison to the smoothed version. We also obtain a non-asymptotic bound on an expected ₁-type error under weak conditions. Some simulations are carried out to examine the performance of the suggested method.