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991.
Acrylamide forms primarily from a reaction between reducing sugars (e.g., glucose and fructose) and an amino acid (asparagine, Asn) formed naturally in foods, including potatoes. This reaction occurs when carbohydrate‐rich foods are heated at temperatures above 120 °C. Multiple potato varieties were transformed with potato genomic DNA that results in down‐regulation of the expression of the asparagine synthetase‐1 gene (Asn1), significantly reducing synthesis of free Asn, and consequently lowering the potential to form acrylamide during cooking. These potatoes with low acrylamide potential (LAP) were tested in agronomic trials, and processed into French fries and potato chips. Decreased levels of acrylamide were measured in these cooked food products when derived from LAP potatoes compared with those derived from conventional potatoes. These reductions can be directly attributed to reduction in Asn levels in the LAP potatoes. The corresponding average reduction in exposure to acrylamide from French fry and potato chip consumption is estimated to be 65%, which would amount to approximately a 25% reduction in overall dietary exposure. Considering that children consume nearly three times more acrylamide than adults on a per kg body weight basis, they would experience the most impact from the reduced acrylamide associated with LAP potatoes. The potential public health impacts, in context of dietary acrylamide exposure reduction, are discussed in this study.  相似文献   
992.
The matching identification problem (MIP) is a combinatoric search problem related to the fields of learning from examples, boolean functions, and knowledge acquisition. The MIP involves identifying a single “goal” item from a large set of items. Because there is commonly a cost associated with evaluating each guess, the goal item should be identified in as few guesses as possible. As in most search problems, the items have a similar structure, which allows an evaluation of each guessed item. In other words, each guessed item elicits partial information about the goal item, i.e. how similar the guess is to the goal. With this information the goal is more quickly identified.The unordered MIP has been studied by Mehrez and Steinberg (ORSA J. Comput. 7 (1995) 211) in which they proposed two different types of algorithms. The purpose of the present paper is to suggest an improved Spanning Heuristic algorithm. Its improvement increases as the problem size increases. Further results and comparisons are derived for the unordered and ordered cases.This research shows that when the search space is very large, it is better to inquire from items that are known not to be the goal (they have been ruled out by previous guesses), for the purpose of acquiring more information about the goal. As the search space is narrowed, it is better to guess items that have not been ruled out.  相似文献   
993.
The career-plateau as challenge to enterprises, employees and consultantsThe authors intend to link life-span-psychology to career-research in order to make understand the phenomenon of career-plateau and how individuals and organisations can deal with it. People take stock in the middle of their lives and assess their personal or professional targets. This process often relates to a personal crisis, especially when the success rate of a job is an important part of the self-concept and hierarchical development has stopped simultaneously. Nevertheless, the desire for a career continues to exist. On top of that what makes it even harder is that the individual has to work at least 20 more years because of demographic reasons. We assume that the way how to manage this crisis has a big influence on performance motivation and that life-span-orientated management development can help the individual to overcome the crisis or even prevent it.  相似文献   
994.
The purpose of this study is to revise and revalidate the End‐User Computing Satisfaction (EUCS) instrument to measure satisfaction with a Web site from a usability perspective. This study is especially important given the increased significance of the Web and the uniqueness of the Web as a computing environment. A total of 176 students participated in a lab simulation that involved a usability evaluation of the Lands' End Web site ( http://www.landsend.com ). Students were asked to complete a set of tasks, record their answers, and then complete the EUCS instrument. Confirmatory factor analysis and invariance analyses were conducted to test the reliability, validity, and generalizability of the revised EUCS. The results show that the EUCS is a valid and robust instrument in the Web environment but that one of the subfactors, timeliness, will need further refinement in the future. Usability practitioners can use the EUCS to measure end‐user satisfaction with a Web site and use the feedback for improving Web‐site design. We describe a case study of an actual usability application that utilized the revised EUCS effectively to support the design of building supply Web sites involving two types of end users, homeowners and contractors. We also propose a typology that researchers can use as a starting point to judge when it is necessary to revalidate an instrument like the EUCS. Finally, we discuss the limitations of our study and present avenues for future research.  相似文献   
995.
Recently, innovation‐oriented firms have been competing along dimensions other than price, lead time being one such dimension. Increasingly, customers are favoring lead time guarantees as a means to hedge supply chain risks. For a make‐to‐order environment, we explicitly model the impact of a lead time guarantee on customer demands and production planning. We study how a firm can integrate demand and production decisions to optimize expected profits by quoting a uniform guaranteed maximum lead time to all customers. Our analysis highlights the increasing importance of lead time for customers, as well as the tradeoffs in achieving a proper balance between revenue and cost drivers associated with lead‐time guarantees. We show that the optimal lead time has a closed‐form solution with a newsvendor‐like structure. We prove comparative statics results for the change in optimal lead time with changes in capacity and cost parameters and illustrate the insights using numerical experimentation.  相似文献   
996.
Biclustering consists in simultaneous partitioning of the set of samples and the set of their attributes (features) into subsets (classes). Samples and features classified together are supposed to have a high relevance to each other which can be observed by intensity of their expressions. We define the notion of consistency for biclustering using interrelation between centroids of sample and feature classes. We prove that consistent biclustering implies separability of the classes by convex cones. While previous works on biclustering concentrated on unsupervised learning and did not consider employing a training set, whose classification is given, we propose a model for supervised biclustering, whose consistency is achieved by feature selection. The developed model involves solution of a fractional 0–1 programming problem. Preliminary computational results on microarray data mining problems are reported.This research work was partially supported by NSF, NIH and AirForce grants.  相似文献   
997.
B. J. M. Ale 《Risk analysis》2005,25(2):231-241
In managing major accident hazards in industry risk, both the United Kingdom and the Netherlands use quantitative risk analysis and quantified risk criteria. These should be understood in the historical, legal, and political context in which they were drawn up. Even when criteria are numerically the same they do not necessarily mean the same thing. The legal and historical context differs widely between the two countries. Nevertheless, it is surprising that the final results in terms of land use and levels of risk are very similar.  相似文献   
998.
The extreme importance of critical infrastructures to modern society is widely recognized. These infrastructures are complex and interdependent. Protecting the critical infrastructures from terrorism presents an enormous challenge. Recognizing that society cannot afford the costs associated with absolute protection, it is necessary to identify and prioritize the vulnerabilities in these infrastructures. This article presents a methodology for the identification and prioritization of vulnerabilities in infrastructures. We model the infrastructures as interconnected digraphs and employ graph theory to identify the candidate vulnerable scenarios. These scenarios are screened for the susceptibility of their elements to a terrorist attack, and a prioritized list of vulnerabilities is produced. The prioritization methodology is based on multiattribute utility theory. The impact of losing infrastructure services is evaluated using a value tree that reflects the perceptions and values of the decisionmaker and the relevant stakeholders. These results, which are conditional on a specified threat, are provided to the decisionmaker for use in risk management. The methodology is illustrated through the presentation of a portion of the analysis conducted on the campus of the Massachusetts Institute of Technology.  相似文献   
999.
Motives and values at work have long been key topics of business and management studies. In a focused review of the literature on the nature of human values, this paper identifies a disconnect with the literature on human motivation, despite the otherwise inherent relatedness of the two fields. Specifically, extant theory and research have conceptualized values generally in terms of ideals, namely desired end‐states that individuals strive to approach. Although values, by this definition, express motivational concerns, theories of human motivation suggest that there are two forces to consider, i.e. approach and avoidance motivation. By applying this ‘two forces’ perspective to value research, this paper identifies a gap in the literature on values: namely, the idea that individuals are also influenced by counter‐ideal values, i.e. end‐states that they deliberately seek to avoid. The identification of this gap opens up new opportunities for value research in general and organizational value research in particular. To pave the way for future research, this paper critically discusses the few studies that have taken first steps in that direction and outlines research questions that may follow for issues such as employer branding and person–organization fit. This paper closes by providing suggestions on how to tackle the issue in organizational practice.  相似文献   
1000.
The current study was carried out per management request to improve the overall quality of telephone customer service among appointment coordinators in a medical clinic. Exceptional telephone customer service included (a) using a standard greeting, (b) speaking in the appropriate tone of voice throughout the call, and (c) answering every call received by the unit. A preintervention analysis suggested that performance deficiencies resulted from weak antecedents, poor knowledge and skills, and weak performance contingencies. Task clarification, goal setting, feedback, and performance-contingent consequences were combined to improve these customer service behaviors for 20 full-time appointment coordinators at the clinic. The study used an ABÁ reversal design with weekly maintenance and 5-month follow-up observations. Introduction of the multicomponent intervention produced visible improvements in greeting (38% increase) and friendly voice tone (22% increase) behaviors; performance was maintained above baseline levels at 5 months postmaintenance. Abandon rates (the percentage of calls not answered by a live voice) remained fairly stable, on average. Findings support the use of a multicomponent intervention to increase telephone customer service behavior in medical clinic settings.  相似文献   
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