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关键词： classification   computer-aided diagnosis   decision tree, classification and regression   tree   mass spectrometry  

摘要： A classification and regression tree (CART) model was trained to classify 41 clinical specimens as disease/nondisease based on 26 variables computed from the mass-to-charge ratio (m/z) and peak heights of proteins identified by mass spectroscopy. The CART model built on all of the specimens (no cross-validation) had an error rate of 4/41 = 10%. The CART model suggests that mass spectra peaks in the 8000-10 000, 20000-30000, 45000-60000, and > 125 000 m/z ranges may be valuable in distinguishing between the disease/nondisease specimens. The area under the receiver operating characteristics curve was 0.80 +/- 0.07 for leave-one-out cross-validation.

关键词： epilithon   grazer   nitrogen   (IN)-I-15   stable isotope tracer   mayfly   caddisfly   functional-feeding groups   nutrient limitation   Lake Superior tributary  

摘要： Primary producer-consumer interactions and N dynamics were studied in a 3(rd)-order reach of Amity Creek, a Lake Superior tributary in northeastern Minnesota (mean discharge = 0.08 m(3)/s). A nutrient-limitation-bioassay experiment showed that primary production was co-limited by N and P To evaluate the importance of grazers in controlling epilithic algal biomass, a grazer-reduction experiment was conducted using ceramic tile epilithon substrates (ambient grazing and low grazing treatments). Grazers significantly reduced epilithic biomass as measured by chlorophyll a, demonstrating that grazers constrain algal primary producers in this system. N-15-enriched NH4Cl was added to the stream for 6 wk, as a stable isotope tracer of N flow through producer and grazer compartments. A comparison of delta(15)N of tile epilithon, incubated for 4 wk during the N-15 addition, to that of bulk epilithon collected from rock scrapings, showed that the thinner epilithon associated with tiles was much more enriched in N-15 than the bulk material. We propose a model of layered epilithon, where the outer, presumably newer, material is more active in N cycling than the inner, presumably older material. This more active material was used more by grazers. The caddisfly Glossosoma and mayflies Paraleptophlebia and Ephemerella were notably enriched in N-15 relative to bulk epilithon, similar to tile epilithon, suggesting that they selectively grazed and/or selectively assimilated the subcomponent of the epilithon that was most active in N cycling in this stream. The mayfly Stenonema was isotopically more similar to bulk epilithon than the other primary consumers. Traditional functional-feeding group classifications of these consumers did not accurately describe their food resource assimilation, as illustrated by their N-15 signatures. Grazers may be even more important in N cycling and retention than previously believed because they assimilate much more N than would be expected based on thei

关键词： 中国   货币政策   作用机制   货币供给   实际产出   Granger影响   趋势转变  

摘要： The effectiveness of monetary policy depends on the period of business cycle。By recognizing the monetary policy regime switching and testing for the money-output relationships,we find that in China’s economy,tight monetary policy slow the economy in the boom more than easy monetary policy accelerates the economy in the *** current situations,the targets of robust monetary policy are to stimulus nominal economy and expand the effective demand.

关键词： 出入境检验检疫   分析科学   现代科技革命   队伍建设   重点实验室建设   科技创新  

摘要： 通过讨论现代科学技术革命与分析科学的相互关系 ,针对分析科学技术的迅速发展及出入境检验检疫面临的机会和挑战 ,提出了如何提高检验检疫实验室的人员素质。

关键词： 二项选择模型   经济周期   货币政策   非对称性  

摘要： 货币政策的非对称性主要是指货币政策在经济周期的不同阶段具有不同的效果。采用二项离散选择模型对货币政策的非对称性进行描述不仅能够度量经济波动和货币政策的状态,而且能够在不确定性条件下检验货币政策产生作用的可能性。在我国经济运行中存在一定程度的货币政策作用的非对称性,因此需要对通货紧缩环境下的货币政策传导机制和作用机制进行更为深入的分析。

关键词： 检验生理学   实验设计训练   科研能力   培养  

摘要： 目的对5年制检验专业学生进行科研、创新能力的培养.方法生理学实验教学中设实验班与对照班,对照班用传统方法上课,实验班进行实验设计训练.结果实验班各项调查指标均高于对照班.结论 实验设计的训练,对培养科研能力及创新能力有一定的效果.

关键词： closure of data   data pretreatment   radial data   V-shaped data  

摘要： On the basis of the results of previous studies, the problem of multivariate classification in the presence of the so-called radial or V-shaped data has been briefly re-examined. Taking into account that the radial data, in the absence of preliminary transformations, usually lead to classifications of samples meaningless from a chemical point of view, five different data transformations have been evaluated and compared in the case of both hypothetical and real samples (real samples, in particular, consisted of archaeological ceramic shards to be classified on the basis of provenance). The following transformations have been used: closure to 100, log row centering, log double centering, row centering, and double centering. The transformed data were then classified by means of hierarchical clustering and principal component analysis (PCA). It has been demonstrated that only the first three transformations lead to correct classifications of radial data, and the causes of this fact have been explained. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： Classification   Community Colleges   Database Design   Educational Research   Local Issues   Research   Two Year Colleges  

摘要： This concluding chapter illustrates the practical results of the five classification proposals. Each classification model has been applied to a common sample of colleges, and the authors review the key implications of this collective exercise.

关键词： 中国   入世   WTO   动植物检验检疫   农业经济   农产品进出口有害生物风险预警机制   农业标准化   ,技术壁垒   体系认证   技术咨询  

摘要： 中国加入世界贸易组织是中国对外开放的里程碑,加入世贸组织为检验检疫部门提供了前所未有的机遇和挑战,我们的职责由过去的把关、服务扩展到用技术手段保护国家利益,担负起我国与其他国家的贸易战中用技术手段进行宏观调控的主力军的责任.同时加入WTO对我国农业将产生重大的影响,土地资源密集型大宗农产品因生产成本过高,已经失去了与国外同类产品的比较优势.劳动密集型农产品的优势和竞争力仍然存在,但国际市场对农副产品的卫生质量、保鲜、包装、生产的质量保证体系等不断提出了新的要求.应对入世挑战,促进农业经济的发展,动植物检验检疫工作应发挥重要作用.

关键词： 分类收集   地区   包装废物   循环利用   循环使用  

摘要： (接上期) 8.2.在城市的分类收集计划里,应该明确下列关于辖区内容器和包装废物的分类收集的事情应该明确: