首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   10篇
  免费   0篇
  2023年   1篇
  2022年   1篇
  2019年   1篇
  2015年   2篇
  2011年   1篇
  2009年   2篇
  2008年   1篇
  1992年   1篇
排序方式: 共有10条查询结果,搜索用时 15 毫秒
1
1.
利用切片方法观察了猞猁Felislynx肝脏的组织结构,应用免疫组织化学方法检测了表皮生长因子(EGF)在肝脏中的表达。结果显示,肝脏外被覆一层结缔组织薄膜,肝小叶不规则且分界不清,肝板、肝血窦及狄氏间隙围绕中央静脉呈放射状排列,肝板由一排肝细胞构成。肝细胞呈圆形或多边形,多为单核,少数具双核,肝细胞间比较松散。肝血窦发达,内可见血细胞。EGF阳性反应主要定位于肝细胞质中,表明EGF可能参与细胞新陈代谢过程的调控。  相似文献   
2.
猞猁(Lynxlynx)是内蒙古赛罕乌拉国家级自然保护区内的顶级捕食者,在维持该地区生态平衡和调节猎物数量上具有重要地位。分析猞猁粪便样品残留物不仅能明确其猎物构成,了解与同域分布其他捕食者的关系,还能为制定物种保护措施和栖息地管理策略提供科学参考。本研究在2006至2008年间利用样线法在该区域收集到35份猞猁粪便样品。通过相对出现频率法对粪样进行食性分析,发现猞猁的主要食物组成以蒙古兔(Lepus tolai,30.85%)和植物(28.72%)较多;年度(χ~2=18.696,P <0.001)和季节性(χ~2=74.695,P <0.001)食物构成均存在显著差异。结果表明,蒙古兔在猞猁的食物组成中占最重要地位;猞猁的食物构成与季节有关,寒冷季节捕食大型猎物,而温暖季节捕食的小型猎物更常见。  相似文献   
3.
We compared probability surfaces derived using one set of environmental variables in three Geographic Information Systems (GIS) -based approaches: logistic regression and Akaike's Information Criterion (AIC), Multiple Criteria Evaluation (MCE), and Bayesian Analysis (specifically Dempster-Shafer theory). We used lynx Lynx canadensis as our focal species, and developed our environment relationship model using track data collected in Banff National Park, Alberta, Canada, during winters from 1997 to 2000. The accuracy of the three spatial models were compared using a contingency table method. We determined the percentage of cases in which both presence and absence points were correctly classified (overall accuracy), the failure to predict a species where it occurred (omission error) and the prediction of presence where there was absence (commission error). Our overall accuracy showed the logistic regression approach was the most accurate (74.51%). The multiple criteria evaluation was intermediate (39.22%), while the Dempster-Shafer (D-S) theory model was the poorest (29.90%). However, omission and commission error tell us a different story: logistic regression had the lowest commission error, while D-S theory produced the lowest omission error. Our results provide evidence that habitat modellers should evaluate all three error measures when ascribing confidence in their model. We suggest that for our study area at least, the logistic regression model is optimal. However, where sample size is small or the species is very rare, it may also be useful to explore and/or use a more ecologically cautious modelling approach (e.g. Dempster-Shafer) that would over-predict, protect more sites, and thereby minimize the risk of missing critical habitat in conservation plans .  相似文献   
4.
猫科动物具有夜行性和活动隐蔽的特点,难以在野外通过直接观察的方式调查种群数量。近年来兴起的自动相机技术,为解决这一难题提供了有效的观察记录手段。为明确欧亚猞猁(Lynx lynx)的种群数量及其野外行为特征,于2010—2012年采用自动相机技术对内蒙古赛罕乌拉国家级自然保护区部分区域进行了调查。在可能出现猞猁的兽道和有蹄类动物投食站等地放置自动相机,3年间共布放90台次,累积25704个相机日,拍摄到猞猁照片154张和录像185段。经对比身体斑纹特征和活动空间,确认2012年在该区域至少有5只猞猁个体,其中2011年和2012年分别发现有母兽与幼兽同时活动,表明该区域分布有一个小而相对稳定的猞猁繁殖种群。猞猁的活动节律表现为典型的夜行性,偶尔也会在白天活动。猞猁的行为类型有取食、威胁、标记、试探、玩耍、舔幼和嗅闻等。调查中没有发现猞猁对自动相机的远红外光产生趋避行为,利用自动相机技术可以作为猞猁种群动态监测和行为研究的重要工具。  相似文献   
5.
猞猁是一种珍贵的野生毛皮动物及观赏动物,具有很高的经济价值。有关猞猁球虫病尚未见报道。长春市动植物园的猞猁发生自然死亡,经病理学及病原鉴定,诊断为球虫病,现报告如下。  相似文献   
6.
<正>猫科动物广泛分布于世界各地(Johnson et al.,2006),全球现存37种猫科动物,其中25种已被国际自然保护联盟(IUCN)列为濒危和易危,86%以上的种群数量处于下降或未知状态(IUCN Red List,2011)。我国有13种猫科动物,占世界种类的35%(王应祥,2003),其中属于国家一级保护的有4种,二级保护的有8种,然而,对这些珍稀物种的生态学研究并不充分(高耀亭,  相似文献   
7.
We compared probability surfaces derived using one set of environmental variables in three Geographic Information Systems (GIS) -based approaches: logistic regression and Akaike's Information Criterion (AIC),Multiple Criteria Evaluation (MCE),and Bayesian Analysis (specifically Dempster-Shafer theory). We used lynx Lynx canadensis as our focal species,and developed our environment relationship model using track data collected in Banff National Park,Alberta,Canada,during winters from 1997 to 2000. The accuracy of the three spatial models were compared using a contingency table method. We determined the percentage of cases in which both presence and absence points were correctly classified (overall accuracy),the failure to predict a species where it occurred (omission error) and the prediction of presence where there was absence (commission error). Our overall accuracy showed the logistic regression approach was the most accurate (74.51% ). The multiple criteria evaluation was intermediate (39.22%),while the Dempster-Shafer (D-S) theory model was the poorest (29.90%). However,omission and commission error tell us a different story: logistic regression had the lowest commission error,while D-S theory produced the lowest omission error. Our results provide evidence that habitat modellers should evaluate all three error measures when ascribing confidence in their model. We suggest that for our study area at least,the logistic regression model is optimal. However,where sample size is small or the species is very rare,it may also be useful to explore and/or use a more ecologically cautious modelling approach (e.g. Dempster-Shafer) that would over-predict,protect more sites,and thereby minimize the risk of missing critical habitat in conservation plans.  相似文献   
8.
研究了非自由生活的4窝11只猞猁幼仔的玩耍行为、亲和及入侵关系的变化.观察到36-57日龄幼仔的同胞打斗行为,这些打斗减少了这些幼仔之间游戏性接触的频次.这个"打斗期"与游戏行为和食性的变化同步发生.打斗后,幼仔游戏性接触的非对称性以及同胞之间的偏爱更加清楚.这些打斗导致了不同窝的幼仔之间等级结构的建立.  相似文献   
9.
<正>猞猁(Lynx lynx Linnaeus, 1758)为食肉目(CARNIVORA)猫科(Felidae)猞猁属(Lynx)的中等体型哺乳动物,主要分布于欧洲、北亚、西亚及中亚地区(蒋志刚等,2015)。猞猁分布较广,数量多,为IUCN红色名录的无危物种(Least Concern, LC)(Breitenmoser et al., 2015)。亚洲地区的猞猁主要栖息在山地森林、无林裸岩地带、密集灌木丛和草原,分布海拔可达4 500 m (汪松,1998)。在中国,猞猁分布于东北、华北、西北和西南地区(高耀亭等,1987;王应祥,2003),野外种群数量较少,属于国家二级重点保护野生动物,  相似文献   
10.
<正>群落内多物种如何共存是群落生态学和生物多样性研究的核心内容之一。经典物种共存理论强调物种之间的生态位分化,侧重于物种对环境的需求,Hutchinson (1957)提出超体积生态位概念,认为物种适合度是由多个因素共同决定,即物种只有在满足其生态位需求的多维空间,  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号