Cross-Contamination During Food Preparation: A Mechanistic Model Applied to Chicken-Borne Campylobacter

We develop a model for bacterial cross-contamination during food preparation in the domestic kitchen and apply this to the case of Campylobacter-contaminated chicken breast. Building blocks of the model are the routines performed during food preparation, with their associated probabilities of bacterial transfer between food items and kitchen utensils. The model is used in a quantitative microbiological risk assessment (QMRA) of Campylobacter in the Netherlands. Using parameter values from the literature and performing elementary sensitivity analyses, we show that cross-contamination can contribute significantly to the risk of Campylobacter infection and find that cleaning frequency of kitchen utensils and thoroughness of rinsing of raw food items after preparation has more impact on cross-contamination than previously emphasized. Furthermore, we argue that especially more behavioral data on hygiene during food preparation is needed for a comprehensive Campylobacter risk assessment.     

Food Safety in the Domestic Environment: An Interdisciplinary Investigation of Microbial Hazards During Food Preparation

It has been established that, to a considerable extent, the domestic hygiene practices adopted by consumers can result in a greater or lesser microbial load in prepared meals. In the research presented here, an interdisciplinary study is reported in which interviews, observations of consumers preparing a recipe, and microbial contamination of the finished meals were compared. The results suggest that, while most consumers are knowledgeable about the importance of cross-contamination and heating in preventing the occurrence of foodborne illness, this knowledge is not necessarily translated into behavior. The adoption of habitual cooking practices may also be important. Potentially risky behaviors were, indeed, observed in the domestic food preparation environment. Eighteen of the participants made errors in food preparation that could potentially result in cross-contamination, and seven participants allowed raw meat juices to come in contact with the final meal. Using a tracer microorganism the log reduction as a result of consumer preparation was estimated at an average of log 4.1 cfu/salad. When combining these findings, it was found that cross-contamination errors were a good predictor for log reduction. Procedural food safety knowledge (i.e., knowledge proffered after general open questions) was a better predictor of efficacious bacterial reduction than declarative food safety knowledge (i.e., knowledge proffered after formal questioning). This suggests that motivation to prepare safe food was a better indicator of actual behavior than knowledge about food safety per se.     

Assessing Interventions to Reduce the Risk of Campylobacter Prevalence in Broilers

As part of a comprehensive risk assessment on the Campylobacter prevalence in the chicken production chain (from young born chicken till chicken fillet) in the Netherlands, we formulated a quantitative model on the transmission dynamics of Campylobacter at Dutch broiler farms. This model is used to quantify the risk of Campylobacter prevalence in broilers at the time that flocks leave the farm for processing. To this end, we assumed that the Campylobacter prevalence is primarily determined by two parameters, that is, the within- and between-flock transmission. The within-flock transmission was assessed fitting experimental data to a logistic growth model and the between-flock transmission was assessed fitting field data to a generalized linear model (GLM), which included three possible infection routes: (1) via an infected flock in the previous cycle, (2) via other infected flocks present on the farm, and (3) from other sources. This model was applied to assess the efficacy of three control scenarios; (1) a ban on other livestock on broiler farms, (2) a ban on thinning, and (3) a reduction of the between-flock transmission. In contrast to the other scenarios, the third one was shown to be most effective. Theoretically, this is accomplished by improved biosecurity. However, the impact of improved biosecurity cannot be specified into specific control measures, and therefore it is not clear what investments are needed. Finally, we also assessed the efficacy of scheduled treatment, that is, fresh meat production solely from test-negative flocks. We found that the reliability of negative test results, which is crucial, strongly depends on the length of time between testing and slaughter. The sensitivity and specificity of the test appeared to be of minor importance.     

大力改进领导方式和领导方法

江泽民同志在安徽视察时强调,进一步改进领导方式和领导方法,实现领导方式和领导方法的创新,是当前加强党的建设,也是做好各项工作面临的一个重大课题.在纪念建党80周年重要讲话中,江泽民同志又重申了这一要求.这一重要思想具有强烈的针对性和重要的现实意义.     

Scheduling to Improve Field Service Quality*

This research addresses the problem of scheduling technicians to travel from customer site to customer site to perform emergency maintenance on office machines, computers, robots, telecommunications equipment, medical equipment, heating/cooling equipment, household appliances, and other equipment. We call this the Traveling Technician Problem (TTP). In its simplest form, the TTP is a multiserver, sequence-dependent, tardiness minimization problem. This research frames the TTP as a service quality maximization problem in which service quality is defined in terms of mean tardiness, mean technician phone response time, mean promise time, and mean response time. Tardiness is defined with respect to contractually guaranteed response times. Industry practice is to use dispatching rules to assign service calls to technicians. This research proposes scheduling procedures to maximize field service quality in a dynamic environment. A simulation experiment was used to compare three dispatching rules and three scheduling procedures for the TTP. The scheduling procedures dominated the dispatching rules on all four service quality measures. The proposed scheduling procedures hold promise for improving service quality in a wide variety of field service organizations and in other scheduling environments as well.     

A Review of Training Strategies to Teach Individuals Implementation of Behavioral Interventions

The purpose of this review is to provide a critical analysis of research on staff training procedures to identify best practices as well as unanswered questions, which may be addressed in future research. We analyzed 24 articles along the dimensions of participant and intervention characteristics; the procedures targeted for training, training components, and mediums of delivery; the duration of training and the effectiveness of the outcomes; the generality; and the social validity of the training strategies. We discussed the implication of the findings as they relate to research and practice.     

领导者韧性领导力的增进思路

韧性领导力是一个组织走出危机、持续成长的核心战略资源,其增进之道在于从领导者的心智思维角度切入,形成批判式思维,培育平衡式思维,激发集体智慧和强化学习能力。     

Psychological Determinants of Reactions to Food Risk Messages

In recent years, European countries have witnessed a number of food crises such as dioxin-contaminated chicken, foot-and-mouth disease, and BSE. In such cases, food might be contaminated by microorganisms or chemicals that could pose a risk to the consumer. These cases attract media attention and might instigate the consumer to reduce the consumption of the allegedly contaminated products. Although a decline in consumption of (potentially) contaminated products has been observed, it is not yet clear what determines the individual's reaction to food risk messages. To study the psychological determinants of the reaction to food risk messages, a survey was conducted in the Netherlands (n= 280). Subjects had to imagine two situations involving chicken contamination and report how they would react behaviorally if this situation occurred. Risk perception, affective response, perceived susceptibility to foodborne disease, self-efficacy, outcome expectation, trust, experience with foodborne disease, and need for information were also assessed. It was found that 60% of the subjects would allegedly avoid the risks by not consuming chicken for a while and approximately 60% would seek additional information. Risk avoidance was significantly related to information seeking and the psychological determinants, especially risk perception, affective response, need for information, perceived susceptibility to foodborne disease, and trust. Seeking information was also significantly related to risk perception, affective response, need for information, susceptibility to foodborne disease, and trust, but to a lesser degree. A model describing the relationships between the variables was tested using AMOS. Results are presented and implications are discussed.     

提升单位治理效能的关键因素与创新路径

治理客观环境复杂化、治理内在需求多样化和治理主体多元化是促使单位提升治理效能的客观要求。从单位角度看,员工参与度、公平感、幸福感和满意度是影响单位治理效能提升的关键因素。单位领导者可以从打造多元共治治理格局、建构公平共建共享制度、优化单位人文关怀机制和完善单位公共服务体系等方面出发创新单位治理机制,提升单位治理效能。     

Faculty Performance Evaluation: Modeling to Improve Personnel Decisions*

Based on likely future changes in faculty evaluation practices, this paper examines how institutions of higher education might operationalize performance evaluation as related to research, teaching, and service. A model is developed that allows coupling performance evaluation and relevant market considerations with merit pay, tenure, and promotion decisions. The approach is specifically applicable to tenure-track faculty members in colleges and universities.     

加强组工干部能力建设的思考

加强组工干部的能力建设,既是一个新话题,又是一个老课题。在开展保持共产党员先进性教育活动中,如何通过进一步加强能力建设,切实发挥组工干部的表率作用,是我们必须认真审视和思考的问题。刻苦学习,充实自己要确立终身刻苦学习的好态度。一要注重学习。要把学习作为进步的基础和阶梯,不受社会上学风不浓、玩风太盛现象的影响,让电子计算机的键盘声代替麻将桌上的洗牌声,让朗朗的读书声代替酒桌上的划拳声。要通过刻苦学习,增强自己的真才实学。否则,一个没有真才实学的人,即使通过种种不正当的手段升到了高位,也终有一天会被别人一脚踹下…     

A Procedure to Improve Compliance with Coal Mine Safety Regulations

Safety performance in underground coal mines consists of a wide array of preventive behaviors designed to lessen the possibility of accidental injury or a major mine disaster. Recognizing that some of the greatest catastrophes in the past have been due to fires and explosions, underground coal mines are now required to establish and maintain working ventilation systems, with numerous support behaviors required on each working section. Compliance is monitored through periodic inspections by Mine Safety and Health Administration (MSHA) inspectors, who have the authority to cite and impose a monetary fine on the company when any of these preventive measures are in non-compliance. The current study was targeted toward a reduction in ventilation violations issued by MSHA inspectors at a mine with four coal-producing sections. Performance data were monitored through weekly inspections of each section by a company health and safety inspector assigned to the mine. Through a combined program of periodic observation, contingent punitive control, praise, and graphic feedback, the mine operated for 10 consecutive months without a ventilation violation.     

A Comparison of Unconstraining Methods to Improve Revenue Management Systems

Asuccessful revenue management system requires accurate demand forecasts for each customer segment. The forecasts are used to set booking limits for lower value customers to ensure an adequate supply for higher value customers. The very use of booking limits, however, constrains the historical demand data needed for an accurate forecast. Ignoring this interaction leads to substantial penalties in a firm's potential revenues. We review existing unconstraining methods and propose a new method that includes some attractive properties not found in the existing methods. We evaluate several of the common unconstraining methods against our proposed method by testing them on intentionally constrained simulated data. Results indicate our proposed method outperforms other methods in two of three data sets. We also test the revenue impact of our proposed method, expectation maximization (EM), and “no unconstraining” on actual booking data from a hotel/casino. We show that performance varies with the initial starting protection limits and a lack of unconstraining leads to significant revenue losses.     

如何有效利用我国失业保险基金以促进再就业

我国失业保险基金大量闲置,促进就业功能难以发挥,国内对失业保险优化相关领域的研究又基本空缺.本文针对这一问题总结了西方基于促进就业的优化失业保险的四种途径,并在此基础上根据我国目前的状况,提出了合理运用我国失业保险基金、优化我国失业保险的一系列政策建议.     

The Potential of Next-Generation Microbiological Diagnostics to Improve Bioterrorism Detection Speed

Emerging, rapid, multivalent, microbial diagnostic technologies can produce results in hours, as contrasted to the standard methods that require at least the better part of a week. Used in bioterrorism surveillance in medical settings, the new biodetectors could significantly reduce the time between a covert attack and its detection. By how much is determined by the intensity of sampling. If used to screen all patients reporting flu-like symptoms to their doctors, this basic level of "front-line" sampling would reduce life-threatening medical floundering and missteps and give responders 3-5 days of warning that they otherwise would not have had. Being miniaturized and amenable to mass production, these devices could reduce the cost of screening to a fraction of current costs and so it is tempting to imagine their use in more intensive bioterrorism screening programs aimed at the apparently healthy population, programs that could detect a covert attack even before the victims felt ill. This article examines the tradeoffs between surveillance effort and probability of detection for such programs. Dual-use deployment, where the biodetector provides some medically useful information in addition to bioterrorism surveillance, is discussed.     

Clinic Overbooking to Improve Patient Access and Increase Provider Productivity*

The problem of patient no‐shows (patients who do not arrive for scheduled appointments) is significant in many health care settings, where no‐show rates can vary widely. No‐shows reduce provider productivity and clinic efficiency, increase health care costs, and limit the ability of a clinic to serve its client population by reducing its effective capacity. In this article, we examine the problem of no‐shows and propose appointment overbooking as one means of reducing the negative impact of no‐shows. We find that patient access and provider productivity are significantly improved with overbooking, but that overbooking causes increases in both patient wait times and provider overtime. We develop a new clinic utility function to capture the trade‐offs between these benefits and costs, and we show that the relative values that a clinic assigns to serving additional patients, minimizing patient waiting times, and minimizing clinic overtime will determine whether overbooking is warranted. From the results of a series of simulation experiments, we determine that overbooking provides greater utility when clinics serve larger numbers of patients, no‐show rates are higher, and service variability is lower. Even with highly variable service times, many clinics will achieve positive net results with overbooking. Our analysis provides valuable guidance to clinic administrators about the use of appointment overbooking to improve patient access, provider productivity, and overall clinic performance.     

Performance Feedback to Improve the Planning and Evaluation of Instructional Programs

Federal and State regulations regarding education for handicapped children require that teachers document plans and evaluate instructional programs on a regular basis. This study investigated the performance of teachers on their documentation of services provided their students. The study employed a multiple baseline across schools designed to assess a performance feedback intervention. Following the initiation of feedback, large increases over baseline were observed for teachers in both schools on two performance measures: Percentage of instructional programs (IPs) planned: and percentage of teachers recording evaluation information on IPs. Results of the study are discussed with respect to the usefulness of performance feedback ss a practical, cost-effective intervention procedure for supervisors and administrators in organizational settings.     

Emergency Department Staff Planning to Improve Patient Care and Reduce Costs

In the face of high staffing costs, uncertain patient arrivals, and patients unsatisfied with long wait times, staffing of medical emergency departments (EDs) is a vexing problem. Using empirical data collected from three active EDs, we develop an analytic model to provide an effective staffing plan for EDs. Patient demand is aggregated into discrete time buckets and used to model the stochastic distribution of patient demand within these buckets, which considerably improves model tractability. This model is capable of scheduling providers with different skill profiles who work either individually or in teams, and with patients of varying acuity levels. We show how our model helps to balance staffing costs and patient service levels, and how it facilitates examination of important ED staffing policies.     

结合RSM和田口方法改进产品/过程质量

对产品/过程参数进行优化时,响应曲面方法(RSM)和田口方法各有优缺点.本文在对两种方法的优缺点分析比较的基础上,提出了运用双响应曲面方法将RSM和田口方法结合起来,实现优势互补,以期能更有效地改进产品/过程质量.     

Management Policies to Improve the Effectiveness of Multi-Station Service Organizations*

A SLAM based simulation model of a multi-station, tandem queuing structure characteristic of a variety of service systems is employed to test various design options for the system. The model is based on an extensive study of the State of Florida driver licensing offices. The multiple objectives of low time in the system for customers and the efficient use of personnel resources are employed to measure the benefits of policy options. The use of simulation analysis permits the incorporation of complex system characteristics, therefore providing a realistic representation of the effects of possible management actions. Effective methods to control labor in such systems are suggested.