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121.
作业是巩固知识、培养能力的重要环节,是教师为了完成教学目标,及时了解学生的学习状况,使学生知识得以巩固,能力得以提高的重要手段。以计算机高职平面设计方向为例,在体现高职特色和课程特色的基础上,对作业的布置和评价进行初步改革探索。  相似文献   
122.
大庆湿地类型及文化旅游价值估算   总被引:1,自引:0,他引:1  
湿地是一种特殊的具有多种功能的生态系统,湿地在保护生物多样性、保持生态环境和可持续发展方面具有重要价值。本文以大庆湿地为研究对象,结合大庆地区2007年LANDSAT TM遥感图形解译数据和实地调查数据,采用地理信息系统技术(GIS),分析大庆湿地分布特征和类型。在此基础上选用费用支出法对大庆湿地文化旅游价值进行了估算:计算结果表明,大庆湿地文化科研价值为4.159 236亿元,大庆湿地旅游价值为7.48亿元,大庆湿地文化旅游价值为11.639 236亿元。  相似文献   
123.
    
Heterogeneity of variance among subclasses of an effect is a potential source of bias in genetic evaluation. Degrees of the heterogeneity of variance among farm‐market‐year‐sex (FMYS) subclasses for carcass weight, beef marbling standard number, rib‐eye area, rib thickness and subcutaneous fat thickness were investigated in Japanese Black cattle. Consequences of adjusting for the heterogeneity on the predicted breeding values (PBVs) or on the genetic indexes derived from the PBVs of the five carcass traits were assessed. A total of 57 461 records were collected between 1997 and 2002 from steers and heifers fattened at farms across Japan. These records were grouped into 1591 FMYS subclasses. Bartlett's test showed that the degree of the heterogeneity of variance among the FMYS subclasses was sizeable in all traits (P < 0.0001). By applying a two‐step adjustment procedure it was possible to reduce the standard deviation, the coefficient of variation and the Gini coefficient of the phenotypic variances by 67.5% to 75.0% in the different traits. The applied adjustment caused a substantial re‐ranking of elite dams in the PBV for each trait as well as in the genetic index. This study provided evidence that the applied adjustment reduces the bias in the PBVs due to heterogeneous variances and increases the accuracy of bull‐dam selection.  相似文献   
124.
This research study evaluated the effect of different additives on the bait consumption by Indian crested porcupine, a serious forest and agricultural pest, under field conditions. Different additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, yeast powder, mineral oil and coconut oil) at 2 and 5% each were tested for their relative preference, using groundnut–maize (1:1) as basic bait. All the additives were tested under a no‐choice test pattern. For control tests, no additive was mixed with the basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait, while 2% saccharin supplemented bait resulted in a non‐significant bait consumption. All other additives did not enhance the consumption of the bait material; rather, these worked as repellents. However, the repellency was lowest with the common salt, followed by egg yolk, egg shell powder, bone meal, peanut butter, mineral oil, fish meal and yeast powder, while coconut remained the most repellent compound. The present study suggested that groundnut–maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine.  相似文献   
125.
126.
    
  1. Amphibian populations worldwide are in decline. Proactive conservation techniques such as translocations into created and restored wetlands have gained popularity in recent years but may fail owing to high predation and low environmental adaptability.
  2. The Mexican axolotl (Ambystoma mexicanum), affected by rapid urbanization, is now possibly extinct in the wild despite millions living in captivity throughout the world.
  3. The aim of this study was to explore whether ponds from an artificial wetland can function as temporary shelters for a viable population of axolotls that could be re-introduced into their native ecosystem in Xochimilco once it is restored.
  4. Egg-laying and hatching of 11 unique axolotl pairs placed into reproductive enclosures and larval survival to 7 weeks and up to 12 months were examined. Physicochemical and biological parameters were estimated and compared among ponds.
  5. The results from this study are encouraging as they suggest that two ponds have adequate conditions for axolotls to reproduce and for larvae and juveniles to survive.
  相似文献   
127.
Unexpected adverse preclinical findings (APFs) are not infrequently encountered during drug development. Such APFs can be functional disturbances such as QT prolongation, morphological toxicity or carcinogenicity. The latter is of particular concern in conjunction with equivocal genotoxicity results. The toxicologic pathologist plays an important role in recognizing these effects, in helping to characterize them, to evaluate their risk for man, and in proposing measures to mitigate the risk particularly in early clinical trials. A careful scientific evaluation is crucial while termination of the development of a potentially useful drug must be avoided. This first part of the review discusses processes to address unexpected APFs and provides an overview over typical APFs in particular classes of drugs. If the mode of action (MoA) by which a drug candidate produces an APF is known, this supports evaluation of its relevance for humans. Tailor-made mechanistic studies, when needed, must be planned carefully to test one or several hypotheses regarding the potential MoA and to provide further data for risk evaluation. Safety considerations are based on exposure at no-observed-adverse-effect levels (NOAEL) of the most sensitive and relevant animal species and guide dose escalation in clinical trials. The availability of early markers of toxicity for monitoring of humans adds further safety to clinical studies. Risk evaluation is concluded by a weight of evidence analysis (WoE) with an array of parameters including drug use, medical need and alternatives on the market. In the second part of this review relevant examples of APFs will be discussed in more detail.  相似文献   
128.
中央财政科研专项绩效考评制度的建立和实践有效地提高了科技经费效益,但是受科研项目规律影响,科研项目成果相对于科研经费投入存在一定的滞后期,目前的科研专项绩效考评无法对科研成果进行较完整的考核。文章回顾了我国中央财政对科研专项开展绩效考评的历史,分析了目前对科研专项绩效考评存在的不足,指出在现行考评制度框架基础上对科研专项引入延迟性考评指标,并对开展延迟性考评工作的适用对象、考评期限等提出有关建议。  相似文献   
129.
网站是高校图书馆的重要组成部分。通过构建对高校图书馆网站的评价指标体系,在此基础上应用模糊综合评价法运用指标体系对高校图书馆网站进行综合评价,旨在为图书馆网站评价方面的研究作出一些有意义的借鉴。  相似文献   
130.
哈尔滨市作为农业大省黑龙江的省会城市,要实现保证国家粮食安全、建设社会主义新农村等目标,必须要加快农业现代化建设。本文通过建立现代农业发展评价的指标体系和基于层次分析法确立权重的综合评价模型,利用1995-2008年数据对哈尔滨市现代农业发展现状进行评价后认为,哈尔滨市现代农业发展始终在进步,各子系统的发展也非常均衡,特别是农业经营水平和新型农民的发展水平比较高。今后应重点加强科技投入和产业结构调整,进行产业化经营。  相似文献   
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