Results 41 to 50 of about 1,091,334 (218)
Taxonomic and functional diversity of urban bees of the world
Conservation Biology, EarlyView.Abstract Bees play a pivotal role in terrestrial environments. Urbanization can affect these organisms and the ecosystem services they provide. However, knowledge of the global diversity of urban bees is limited. Thus, we summarized data on urban bee species identities and occurrences; compared distributions of all bees with those found in urban ...
João C. F. Cardoso +10 more
wiley +1 more source
Conservation Biology, EarlyView.Abstract Bycatch in fisheries is one of the most serious threats to pelagic seabirds, causing major population declines. Mitigation measures can reduce bycatch substantially, but many fisheries fail to apply best practices, and seabird mortality remains high.
V. Warwick‐Evans +2 more
wiley +1 more source
阶层差异的淡化与地区差异的凸显——西部大学生的学业困境探究 [PDF]
, 2018 对大学生学习的研究,阶层差异是一个重要视角。大学生所处阶层的不同并不直接导致其学业表现不同,真正发挥影响的是不同阶层所拥有的文化资本存在着明显的差异。文化资本的差异并不仅仅体现在不同阶层之间,东西部地区由于经济、社会、教育发展水平的不同,文化资本也存在着明显差距。对比不同阶层、不同地区大学生学业成绩、学习动机和学习感受,可以发现阶层差异尽管存在,但却不是反差最明显的。更大的差距体现在东西部地区之间,东部地区的大学生在英语学习、内部动机水平、学习感受上明显优于西部大学生 ...
周序
core +1 more source
Zhongguo shiyan zhenduanxue, 2007 目的本研究旨在为乙型肝炎病毒（HBV）的基因型分布与临床流行病学的关系提供证据。方法采用多对型特异性引物套式聚合酶链反应对吉林省194份来自慢性肝炎、肝硬化及肝癌患者中的HBV阳性血清进行基因分型,并采用卡方检验分析基因构成比的差异。结果在194例HBV阳性血清样品中B型16例、C型172例、BC混合型6例,未发现其它型别的病毒。肝硬化与肝癌患者中乙肝病毒的基因型构成比的差异无统计学意义,而慢性肝炎与肝硬化患者中乙肝病毒的基因型构成比的差异有统计学意义,男女患者所携带的病毒基因型差异无统计学意义 ...
刘桂艳 +10 more
doaj
Conservation Biology, EarlyView.Abstract Knowledge of species distributions is essential for informing policies on nature conservation and restoration. However, updating them on a regular basis and doing so in a harmonized manner at the international level is difficult. The European Bird Census Council integrated national monitoring data covering 5 years to update farmland bird ...
Sergi Herrando +54 more
wiley +1 more source
, 2009 本文首先界定了垂直差异化、属性间水平差异化和属性内水平差异化的内涵。然后深入分析了这些差异化与需求、成本以及价格等变量之间的关系,并在此基础上探讨了三种基于价格差异的差异化类型——溢价差异化、平价差异化和低价差异化——的形成机理。这为企业走出“要么差异化要么低成本“的两难境地提供了理论依据。*本文获国家自然科学基金资助项目(批准号:70672099 ...
莫长炜
core
非小细胞肺癌患者化疗前后血清VEGF/血小板数和TGF-β1检测的临床意义
Zhongguo shiyan zhenduanxue, 2017 目的探讨非小细胞肺癌（NSCLC）患者化疗前后血清VEGF/血小板数和TGF-β1浓度的变化,探讨两者在病情监测中的临床价值。方法 72例NSCLC患者化疗前采用酶联免疫法测定血清VEGF/血小板数和TGF-β1浓度,化疗采用GP方案,连用2周期,治疗结束后1周再次测定血清VEGF/血小板数和TGF-β1浓度,并行胸部CT检查,根据CT结果分为化疗有效组（完全缓解+部分缓解）和无效组（病情稳定+疾病进展）,组间比较采用t检验 ...
顾涛 +6 more
doaj
Assessing differences among elasmobranch nurseries to aid conservation based on a genomics framework
Conservation Biology, EarlyView.Abstract Elasmobranch nurseries often differ in environmental conditions, demographics, and use patterns. These differences affect the distribution of genetic variation among nurseries. However, conservation and management strategies often fail to account for such differences because they are difficult to characterize.
Dominic G. Swift +8 more
wiley +1 more source
Zhongguo shiyan zhenduanxue, 2010 目的建立脊髓缺血再灌注损伤双向凝胶电泳图谱,对照观察蛋白质的差异表达。方法建立脊髓缺血再灌注损伤模型,获取损伤和正常脊髓的蛋白质组双向电泳荧光图谱,观察差异蛋白的不同时间点的变化规律,建立缺血再灌注24 h与正常脊髓蛋白质组的匹配差异图谱,鉴定差异蛋白。结果成功建立损伤和正常的双向电泳荧光图谱和肽质量指纹图谱,比较再灌注损伤24 h组与正常组可检测到46个蛋白差异点,鉴定出10个差异蛋白。结论损伤24 h组较其他组变化明显,与正常脊髓的蛋白质组存在明显差异。
朱本清, 杨小玉, 顾锐, 邱宾涛
doaj
Role of funders in embedding tests in conservation practice
Conservation Biology, EarlyView.Abstract Effective conservation practice requires decisions based on reliable and relevant evidence, but significant gaps in the evidence base exist. Incorporating well‐designed tests of the effectiveness of interventions for biodiversity in conservation projects is one of the best ways to scale up the rate of evidence generation.
Rebecca K. Smith +28 more
wiley +1 more source