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51.
Injury Scaling as a means for classifying the extent of trauma has a long histroy. This paper describes the origin, development and usage of the Abbreviated Injury Scale. Major revisions to AIS-80 are discussed in detail. Both the value of the AIS as a research tool and its limitations are presented. The critical need for training AIS users in proper application is addressed. The future role of the Committee on Injury Scaling is explained, and three potential uses of the AIS are suggested as priority items. The paper, accompanied by a comprehensive bibliography, serves as a basic state of the art reference for physicians and others researchers in the traffic medicine and highway safety field. 相似文献
52.
Systems used in complex, multi-agency environments have a number of inherent problems and challenges that in many cases, lead to systems failure. The area of system failure has been the subject of extensive research in the past. It has been well documented in a number of places that information systems are difficult to build and are prone to failure. This paper examines system failure from a social perspective in the context of building systems in complex environments. Through a case study modelling approach, a framework has been developed to assist in building information systems in such complex multi-agency environments. The paper introduces this framework through a study of a number of challenges confronting the builder of information systems in complex, social, multi-agency environments. We examine the role of task accountability and problems identifying authority as key reasons why systems are rejected by users. We introduce a task accountability model to help understand this problem. We conclude by identifying work still to be carried out within the study. 相似文献
53.
Angela Bonifati Elaine Chang Terence Ho Laks V. S. Lakshmanan Rachel Pottinger Yongik Chung 《The VLDB Journal The International Journal on Very Large Data Bases》2010,19(2):231-256
Peers in a peer-to-peer data management system often have heterogeneous schemas and no mediated global schema. To translate queries across peers, we assume each peer provides correspondences between its schema and a small number of other peer schemas. We focus on query reformulation in the presence of heterogeneous XML schemas, including data–metadata conflicts. We develop an algorithm for inferring precise mapping rules from informal schema correspondences. We define the semantics of query answering in this setting and develop query translation algorithm. Our translation handles an expressive fragment of XQuery and works both along and against the direction of mapping rules. We describe the HePToX heterogeneous P2P XML data management system which incorporates our results. We report the results of extensive experiments on HePToX on both synthetic and real datasets. We demonstrate our system utility and scalability on different P2P distributions. 相似文献
54.
Objective: The expected emotional consequences of future actions are thought to play an important role in health behavior change. This research examined whether anticipated affective consequences of success and failure vary across stages of physical activity change and differentially predict physical activity adoption as compared to maintenance. Design: Using a prospective design over a 3-month period, a community sample of 329 healthy, middle-aged adults were assessed at 2 time points. Main Outcome Measures: Anticipated positive and negative emotions, stage of behavior change (precontemplation [PC], contemplation [C], preparation [P], action [A], maintenance [M]), and level of physical activity. Results: At baseline, anticipated positive emotions were greater in C versus PC, whereas anticipated negative emotions were greater in M versus A and in M versus P. Higher anticipated positive but not negative emotions predicted physical activity adoption and maintenance after 3 months. Conclusion: Although the expected affective consequences of future success and failure differentiated among individuals in the early and later stages of physical activity change, respectively; only the anticipated affective consequences of success predicted future behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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利用准则实现校准图像质量评测 总被引:1,自引:0,他引:1
利用软件工具定量分析数字成像系统的性能可以优化整体图像质量
从手机相机到便携式摄像机,数字成像技术在人们的生活中无处不住。尽管消费者的选择越来越多,但现在仍没有标准化的客观评价量度来定量分析这些设备的整体性能。目前已有数种由国际标准组织(ISO)制定的标准可以对性能的几个不同方面予以量化, 相似文献
58.
Manuela Tosin Dr. Lorena Betancor Dr. Elaine Stephens Dr. W. M. Ariel Li Peter F. Leadlay Prof. 《Chembiochem : a European journal of chemical biology》2010,11(4):539-546
Modular biocatalysis is responsible for the generation of countless bioactive products and its mining remains a major focus for drug discovery purposes. One of the enduring hurdles is the isolation of biosynthetic intermediates in a readily‐analysed form. We prepared a series of nonhydrolysable pantetheine and N‐acetyl cysteamine mimics of the natural (methyl)malonyl extender units recruited for polyketide formation. Using these analogues as competitive substrates, we were able to trap and off‐load diketide and triketide species directly from an in vitro reconstituted type I polyketide synthase, the 6‐deoxyerythronolide B synthase 3 (DEBS3). The putative intermediates, which were extracted in organic solvent and characterised by LC‐HR‐ESI‐MS, are the first of their kind and prove that small‐molecule chain terminators can be used as convenient probes of the biosynthetic process. 相似文献
59.
Chen Y Allegood J Liu Y Wang E Cachón-Gonzalez B Cox TM Merrill AH Sullards MC 《Analytical chemistry》2008,80(8):2780-2788
The quality of tissue imaging by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) depends on the effectiveness of the matrix deposition, especially for lipids that may dissolve in the solvent used for the matrix application. This article describes the use of an oscillating capillary nebulizer (OCN) to spray small droplets of matrix aerosol onto the sample surface for improved matrix homogeneity, reduced crystal size, and controlled solvent effects. This system was then applied to the analysis of histological slices of brains from mice with homozygous disruption of the hexb gene (hexb-/-), a model of Tay-Sachs and Sandhoff disease, versus the functionally normal heterozygote (hexb+/-) by imaging MALDI-MS. This allowed profiling and localization of many different lipid species, and of particular interest, ganglioside GM2, asialo-GM2 (GA2), and sulfatides (ST). The presence of these compounds was confirmed by analysis of brain extracts using electrospray ionization in conjunction with tandem mass spectrometry (MS/MS). The major fatty acid of the ceramide backbone of both GM2 and GA2 was identified as stearic acid (18:0) versus nervonic acid (24:1) for ST by both tissue-imaging MS and ESI-MS/MS. GM2 and GA2 were highly elevated in hexb-/- and were both localized in the granular cell region of the cerebellum. ST, however, was localized mainly in myelinated fiber (white matter) region of the cerebellum as well as in the brain stem with a relatively uniform distribution and had similar relative signal intensity for both hexb+/- and hexb-/- brain. It was also observed that there were distinct localizations for numerous other lipid subclasses; hence, imaging MALDI-MS could be used for "lipidomic" studies. These results illustrate the usefulness of tissue-imaging MALDI-MS with matrix deposition by OCN for histologic comparison of lipids in tissues such as brains from this mouse model of Tay-Sachs and Sandhoff disease. 相似文献
60.
Elaine E. Vaughan Hans G. H. J. Heilig Erwin G. Zoetendal Reetta Satokari J. Kevin Collins Antoon D. L. Akkermans Willem M. de Vos 《Trends in Food Science & Technology》1999,10(12):1393
Functional foods comprising probiotic bacteria are receiving increasing attention from the scientific community and science funding agencies [1]. An essential aspect relating to the functionality of probiotic-based foods is to develop molecular methods to determine the presence, activity and viability of probiotic bacteria in the human gastrointestinal (GI) tract [2]. The GI tract is composed of a complex ecosystem of various microbial habitats colonized by numerous different commensal micro-organisms. This indigenous gut microbiota is essential to the overall health of the host by performing important physiological functions. In particular, they protect against pathogenic bacteria and drive the development of the immune system during neonatal life. Further metabolic activities of the GI microbiota that beneficially affect the host include continued degradation of food components, vitamin production, and production of short chain fatty acids that feed the colonic mucosa. It is clear that factors such as diet, sickness, stress, or medication can result in loss of well-being of the host, and it is assumed that some of these symptoms are due to perturbation of what is termed the normal balance of the gut microbiota. Knowledge of the structure and function of the standard microbiota, and its response to diet, genetic background and lifetime of the host must be taken into account when designing probiotic-based functional foods. The application of molecular techniques for detection and identification of microbes has provided a major breakthrough in the analysis of microbial ecosystems and their function [3]. The successful application and further potential of these molecular methods to study probiotic bacteria and their impact on the standard GI microbiota is discussed below. 相似文献