共查询到20条相似文献，搜索用时 530 毫秒
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大熊猫(Ailuropoda melanoleuca)是我国独有的珍稀濒危物种,其因适应竹子资源的季节变化而进行垂直迁徙,关于其迁徙模式和影响迁徙的因子目前还不甚明确。为了探究影响大熊猫垂直迁徙的因子,于2013年10月至2014年9月,在陕西省佛坪国家级自然保护区三官庙设立了9条样线,共布设52台红外相机对大熊猫的垂直迁徙时间进行研究;同时,结合气象监测数据探究气温、降雨量、湿度和积雪覆盖等因子对大熊猫迁徙活动的影响。研究结果表明,大熊猫垂直空间分布季节性差异明显,7月主要在高海拔秦岭箭竹分布区活动,而2月则主要在低海拔巴山木竹分布区活动。大熊猫从冬居地向夏居地迁徙迅速,仅1~3d即可完成,而从夏居地向冬居地迁徙经历时间较长。气温、积雪覆盖、湿度和降雨量等因素都会对大熊猫的迁徙活动产生影响,大熊猫喜欢选择在“最适温度”区域活动,当高海拔区域出现积雪覆盖时,就会迁徙到低海拔活动。湿度和降雨量主要通过控制竹子发笋和生长来影响大熊猫的迁徙。研究证实了大熊猫的垂直迁徙现象,并获得了关于大熊猫迁徙模式和影响因子相关的较为详细的基础数据,为野生大熊猫的保护提供理论依据。 相似文献
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调查了玉门市移民区社会经济及林果业发展现状,分析了目前移民区发展特色林果产业的不利因素和存在问题,提出了移民区发展特色林果产业的思路。科学规划,合理布局,因地制宜,明确以葡萄、枸杞为重点,甘草等为辅的特色林果产业布局。通过政策扶持、科技服务、市场引导,发展壮大产业规模,以移民区林果业的发展带动全市发展枸杞、葡萄、甘草等产业,建成6667hm2以上的产业基地,并带动相关产业链的发展,成为农村经济新的增长点,改善和提高移民区群众生产生活水平。 相似文献
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《Fitoterapia》2014
Pellitorine (PT), an active amide compound, is well known to possess insecticidal, antibacterial and anticancer properties. In this study, we first investigated the possible barrier protective effects of pellitorine against pro-inflammatory responses induced by lipopolysaccharide (LPS) and the associated signaling pathways in vitro and in vivo. The barrier protective activities of PT were determined by measuring permeability, monocyte adhesion and migration, and activation of pro-inflammatory proteins in LPS-activated human umbilical vein endothelial cells (HUVECs) and in mice. We found that PT inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs) and adhesion/transendothelial migration of monocytes to human endothelial cells. PT also suppressed LPS-induced hyperpermeability and leukocyte migration in vivo. Further studies revealed that PT suppressed the production of tumor necrosis factor-α (TNF-α) or Interleukin (IL)-6 and activation of nuclear factor-κB (NF-κB) or extracellular regulated kinases (ERK) 1/2 by LPS. Moreover, treatment with PT resulted in reduced LPS-induced lethal endotoxemia. These results suggest that PT protects vascular barrier integrity by inhibiting hyperpermeability, expression of CAMs, and adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases. 相似文献
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Pinus massoniana Lamb is a Chinese red pine species used in traditional medicine for the treatment of a variety of human health disorders. Recent studies have shown that P. massoniana bark extract (PMBE) has an anti-proliferation effect on cancer cells. However, it is not clear if PMBE affects cancer cell migration and/or invasion. We tested the effect of PMBE, which has B-type procyanidin as its main constituent, on the adhesion and migration capabilities of HeLa cells, a human cervical cancer cell line, cultured in vitro. Our results showed that PMBE has no significant effect on the adhesion capability of HeLa cells, but strongly inhibits their migration. This finding suggests that PMBE could be a potential therapeutic agent for metastatic cancer. 相似文献
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2008年的9月29日至10月28日对云南巍山隆庆关秋季夜间迁移鸟类环志进行了研究。共网捕迁移鸟109种2 347只,分属11目19科,其中雀形目共71种1 830只,占总网捕种类的65.14%和总数量的77.97%,表明该地迁移鸟类以雀形目等中小型鸟类为主,雀形目鸟类数量优势度十分显著。对网捕迁移鸟进行多样性分析,Shannon—Weaner指数为0.406,Pielou均匀度指数为2.955,F指数为12.68,G指数为3.835,G—F指数为0.698,表明该地迁移鸟的种、属、科等分类阶元多样性均一般。 相似文献
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C.W. Woodall C.M. Oswalt J.A. Westfall C.H. Perry M.D. Nelson A.O. Finley 《Forest Ecology and Management》2010
The lack of objective tree species lists hinders the assessment of climate change effects on tree species distributions. The goal of this study was to develop and evaluate criteria for selecting tree species used in large-scale tree migration monitoring efforts. The results of this study indicate that tree migration conclusions are highly dependant on the species selected for examination. It was found that tree species’ median latitudes or forecasted future areas provided objective criteria for development of species lists for migration hypothesis testing with the latter being insensitive to simulation error. Furthermore, only 10–15 of the top species, in terms of high median latitudes or loss in forecasted future area, are needed to maximize the sensitivity of a migration index. The use of such criteria in this study indicated a northward shift of sensitive tree populations of 27 km. It is suggested that examining species only the most likely to migrate serves as an objective starting point for migration detection. In contrast, the inclusion of all tree species commonly observed in large-scale forest inventories can obfuscate migration detection with tree species that have little ecological reason to immediately migrate in a changing climate. 相似文献
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指出了矿山开采引发的生态环境问题已经逐渐成为世界性的问题,对矿山水土环境中重金属污染研究现状、迁移转化进行了综述。 相似文献
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红角鸮在山西省内分布广泛,笔者于2008年至2010年在阳圪台林场对红角鸮的迁徙、种群数量、繁殖特性、栖息地和食物组成等进行了生态调查,结果表明,红角鸮在山西省的迁徙特点是每年最早迁入的日期差异为2 d~4 d,最晚迁离的日期差异为1 d~4 d,居留期为162 d~167 d,间隔期为198 d~204 d;红角鸮繁殖季前的种群数量为0.75只/km2,繁殖季后为1.08只/km2;鼠类、两爬类、昆虫类等为其主要食物。 相似文献
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In the range of doses of 250-500 mg/kg (given i.p.) the aqueous extract of Loasa speciosa leaves showed an inhibitory effect on leukocyte migration, and a reduction on the pleural exudate, as well as dose-dependent anti-inflammatory and peripheral antinociceptive activities. 相似文献
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2011-2013年冬季,作者采用分组全天跟踪的方法,调查小太平鸟迁徙期活动特征和食性。结果证明:小太平鸟冬季由北向南成群迁徙过程中,会在某个生境优良的区域停留取食9~15日、成群活动在树冠上部。小太平鸟在迁徙期停留区域取食植物果实种类有20种,有人工栽培树种果实,也有野生树种果实。今后应持续迁移路线、停歇地、种群动态监测。 相似文献