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1.
若尔盖湿地国家级自然保护区地处青藏高原东缘,该地区分布有3种两栖类:高原林蛙(Ranakukunoris)、倭蛙(Naroranapleskei)和岷山蟾蜍(Bufominshanica),均为青藏高原特有种。研究在保护区内设定了16个50m×50m的样地(每个样格分为25个10m×10m样格),对每个样格中3种两栖类及环境因子进行了调查。根据3种两栖类分布点距离水体的最远距离初步确定若尔盖保护区高原林蛙(Ranakukunoris)、倭蛙(Naroranapleskei)和岷山蟾蜍(Bufominshanica)的陆地核心生境半径分别为:1000m、55m和580m。由于过大的陆地核心生境在实际保护工作中存在操作上的困难,因此本文提出最小陆地核心生境的概念:在某一季节,不同性别和生活史阶段的某种动物的90%个体完成该季节正常生命活动所通过或者利用的陆地。由此概念,根据高原林蛙90%的雌体、雄体和幼体分布确定其最小陆地核心生境半径为51m。最后通过最优化理论对高原林蛙和岷山蟾蜍分布格局与水体距离、草本层盖度、两栖类密度之间的作用机制进行了探讨,并指出陆地核心生境的范围与其所在生境景观及本种和其他动物种群状况有密切关系。  相似文献   

2.
昆明地区滇蛙与昭觉林蛙同域分布种群的生境利用比较   总被引:1,自引:2,他引:1  
周伟  李明会  麦紫  李伟 《动物学研究》2006,27(4):389-395
现有两栖类生境研究报道多局限于定性描述,缺乏定量数据和统计分析支撑。以蛙的发现点为圆心,作半径1m的样圆,测量12个生态因子。调查共记录滇蛙(Ranapleuraden)133只和昭觉林蛙(Ranachaochiaoensis)62只。采用两独立样本t-检验和非参数Mann-WhitneyU-检验比较两种蛙对同一生境的利用,结果表明,在干燥草地生境仅最高植物高度差异显著;湿润草地生境至水源距离和水百分比差异极显著,水草百分比和湿泥百分比差异显著;水体生境各种生态因子的差异均不显著。主成分分析结果显示,在不同生境中滇蛙和昭觉林蛙所选择的因子往往相同或者顺序颠倒,但这些因子的值几乎均是反向分离的,即小生境不相同。两种蛙的生境利用各有偏好。滇蛙日间活动主要在水体,而昭觉林蛙则在湿润草地和干燥草地。两种蛙对泥地生境利用都少。不同体长的滇蛙对水体生境利用度均较高。昭觉林蛙随着体长增加,对隐蔽条件好的湿润草地和干燥草地生境利用度增加,对水体的利用度减少。  相似文献   

3.
2012—2014年,在长白山自然保护区道路上选取3条长10 km的样带,样带两侧出现的每个水体为小样方,测量水体类型、郁闭度、水体面积、水体深度、水质、集水池形状、离道路距离、集水池形成时间等8个生境因子,对中国林蛙Rana chensinensis、极北鲵Salamandrella keyserlingii和中华大蟾蜍Bufo gargarizans繁殖期的生境选择进行了研究。结果表明:(1)中国林蛙对排水沟和水塘2种类型的选择不具有统计学意义(P>0.05),极北鲵对水塘的选择极显著高于排水沟(P≤0.01),而中华大蟾蜍则显著选择水塘。(2)极北鲵选择大于120 m2的集水池,中华大蟾蜍在120~180 m2的集水池出现率高。(3)极北鲵对水体深度选择具有高度统计学意义(P≤0.01),而中国林蛙对水体深度的选择不具有统计学意义(P>0.05),中华大蟾蜍产卵主要选择在水体深度80 cm以上的集水池,(4)中国林蛙和中华大蟾蜍对集水池离道路距离的选择不具有统计学意义,极北鲵对离道路不同距离的集水池的选择有高度统计学意义。  相似文献   

4.
周伟  李明会  麦紫  李伟 《动物学研究》2006,27(4):389-395
现有两栖类生境研究报道多局限于定性描述,缺乏定量数据和统计分析支撑。以蛙的发现点为圆心,作半径1 m的样圆,测量12个生态因子。调查共记录滇蛙(Rana pleuraden)133只和昭觉林蛙(Rana chaochiaoensis)62只。采用两独立样本t-检验和非参数Mann-Whitney U-检验比较两种蛙对同一生境的利用,结果表明,在干燥草地生境仅最高植物高度差异显著;湿润草地生境至水源距离和水百分比差异极显著,水草百分比和湿泥百分比差异显著;水体生境各种生态因子的差异均不显著。主成分分析结果显示,在不同生境中滇蛙和昭觉林蛙所选择的因子往往相同或者顺序颠倒,但这些因子的值几乎均是反向分离的,即小生境不相同。两种蛙的生境利用各有偏好。滇蛙日间活动主要在水体,而昭觉林蛙则在湿润草地和干燥草地。两种蛙对泥地生境利用都少。不同体长的滇蛙对水体生境利用度均较高。昭觉林蛙随着体长增加,对隐蔽条件好的湿润草地和干燥草地生境利用度增加,对水体的利用度减少。  相似文献   

5.
为考察道路和道路施工对若尔盖高寒泥炭湿地野生动物的影响,我们在穿过若尔盖湿地的2条道路两侧,对距道路不同距离的小型兽类和鸟类分布进行了调查,其中小型兽类调查深度距离公路800m,鸟类调查深度距离公路400m。施工中的国道213线路两侧黑唇鼠兔(Ochotonacurzoniae)洞穴高密度区域离道路更远,在道路两侧400m处达到峰值,极显著高于距离道路10m处的密度;而在正常运营中的省道209线两侧,其洞穴密度在200m处达到最高值,与其他距离的洞穴密度没有显著性差异。无论在国道213线还是省道209线,道路对高原鼢鼠(Myospalaxbaileyi)洞穴分布的影响均未达到显著性水平。在正常运营的省道209线两侧,高原鼢鼠土堆密度最高区域为距离道路100m处;而施工的道路两侧高原鼢鼠土堆密度最高区域则出现在距离道路10m处,第二高峰出现在距离道路400m处。雀形目和隼形目鸟类的分布均呈现距离道路越远密度越高的趋势,但是只有距离道路400m处雀形目鸟类的密度显著高于50m与200m处;距离道路不同距离的样线中隼形目鸟类密度和物种丰富度没有显著性差异。由此可以看出,施工中的道路对黑唇鼠兔的影响区域比正常运营的道路更宽,其公路效应域达到400m,400m的调查深度对鸟类尤其是隼形目鸟类来说可能还略有不足。但是,根据此深度的调查可以确定施工中的国道213线雀形目和隼形目鸟类的公路效应域宽度大于400m。  相似文献   

6.
四川省若尔盖季节性水塘周边高原林蛙夏秋季活动特征   总被引:2,自引:0,他引:2  
影响无尾两栖类活动的因素很多,水体是最主要的因素之一。本研究采用样线法,分别于2006年7月和9月下旬对若尔盖季节性水塘周边高原林蛙(Rana kukunoris)的活动特征进行了研究。样线宽2m,长70-150m,采用十字交叉法,基本按照东、南、西、北、东北、西北、东南、西南方向设置8条样线。结果表明:夏季高原林蛙主要在水塘周边活动,高原林蛙遇见率与水塘距离呈显著负相关(Pearson,成体:r=?0.479,P<0.05;亚成体:r=?0.480,P<0.05);90%的高原林蛙个体在距离水塘110m范围内活动,亚成体比成体更接近水体活动,远离水塘的成体选择泉眼和草沓草地活动。秋季高原林蛙的活动与水塘距离无显著相关性(Pearson,r=?0.016,P>0.05),水塘周边高原林蛙的遇见率很低,远离水塘的高原林蛙偏向选择泉眼活动。  相似文献   

7.
王刚  李成  吴军  韩金锋  江建平  谢锋 《生态学报》2016,36(17):5556-5563
近几十年来,全球两栖动物种群衰减显著,两栖动物的生存现状引起了越来越多的生态学家和保护生物学家的关注。若尔盖湿地不仅是世界上最大的一块高原泥炭沼泽湿地,也是我国生物多样性保护的热点地区之一。该地区分布有3种两栖类:高原林蛙(Rana kukunoris)、倭蛙(Narorana pleskei)和中华蟾蜍岷山亚种(Bufo gargarizans minshanica)。已有研究发现该3种两栖动物种群数量均有不同程度的下降。采用人工掩蔽物法,在2011—2014年对该地区中华蟾蜍种群生态做了连续追踪。结果表明:该区域中华蟾蜍种群数量逐年波动较大,年龄结构数据显示该种群处于增长期;中华蟾蜍为聚集分布,且发现率与水体距离呈显著的线形关系(P0.01),在样地范围内离水体越远,发现的个体越多;线形样方比方形样方捕获动物的效率更高(P=0.018);中华蟾蜍亚成体的肥满度季节间无明显差异;中华蟾蜍具有较强的迁徙能力,可能沿着固定的线路周而复始的迁徙。对于家域范围大,迁徙距离远的中华蟾蜍这类物种,应加强最适栖息地的保护并防止栖息地破碎化。  相似文献   

8.
我们于2006年7月对分布于青藏高原东部若尔盖高寒湿地的7只高原林蛙(Rana kukunoris)进行了追踪研究。Monte-Carlo模拟表明:在研究期内高原林蛙的运动是随机的,还没有开始迁移。高原林蛙的平均运动距离为7.1m,雌雄运动距离没有差异。95%和50%Kernel家域分别为796.2m2±704.0m2和119.9m2±94.6m2,MCP家域为157.9m2±119.5m2。雌雄高原林蛙生境选择存在差异,雄性倾向于在洞穴较多的生境中运动和隐蔽,而雌性倾向于在草丛中运动和藏匿;早晨高原林蛙选择地面温度较高、相对湿度较大的微生境活动,雌雄活动点的空气温度、相对湿度和植被高度没有显著差异。追踪个体的微生境利用表明:高原林蛙和哺乳类洞穴具有很强的相关性。  相似文献   

9.
了解动物的生境特征及其生境选择性,对于动物野生种群的保护具有重要意义。2013年9月,在浙江温州楠溪江流域对国家二级保护动物虎纹蛙的野外生境进行了研究,并利用生境喜好系数和主成分分析法对其生境选择性进行了分析。结果表明:虎纹蛙偏好的生境特征为地形较平缓,坡度较小;地表基质类型为淤泥和细沙,相对湿度较大;植被类型为水稻和草丛,高度和盖度适中;离大型水体的距离较远,离小型水体的距离较近,其栖息水域为静水水域,流速较缓、深度较浅、水质较好、温度较高;离农田的距离较近,离道路的距离适中,离居民点的距离较远;影响虎纹蛙生境选择的主要因子为坡度、坡位、植被高度、植被盖度、地表基质类型、地表温度、离水体的距离、水体温度、水体p H、水体氧含量、离农田的距离和离道路的距离。  相似文献   

10.
长白山区道路建设对两栖类繁殖生境带来减少和退化的影响,为缓解和恢复路域受损两栖类繁殖生境,于2021年3月末至5月初,在吉林长白山国家级自然保护区环区公路两侧100 m内,选择40个面积>10 m2,深度>15 cm的池塘,放置10个网框和20个树枝框作为辅助材料开展极北鲵Salamandrella keyserlingii和中国林蛙Rana chensinensis繁殖生境恢复实验。结果显示:(1)网框和树枝框显著提升了极北鲵对繁殖池的利用率,但对中国林蛙的影响不显著;(2)极北鲵对树枝框利用率(85.00%)显著高于网框(50.00%)(P=0.03);(3)实验组的产卵数量(极北鲵197.00粒±11.29粒,中国林蛙149.00粒±13.74粒)均高于对照组(极北鲵128.00粒±11.32粒,中国林蛙88.00粒±14.12粒),但差异不显著。建议今后在长白山区路域结合两栖类动物通道设置、取弃土场恢复工程营造两栖类繁殖生境时,首选树枝框、其次选网框作为两栖类繁殖产卵的媒介。  相似文献   

11.
The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.  相似文献   

12.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

13.
This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.  相似文献   

14.
A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.  相似文献   

15.
The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γj in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γj are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO3 (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li+ are: Cs+ (1.38), Rb+ (1.32), K+ (1.31), Na+ (1.16), TMA+ (0.53), TEA+ (0.45), TBA+ (0.03), Cl (0.19), glutamate (0.04), and NO3− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.  相似文献   

16.
17.
The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid.  相似文献   

18.
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

19.
《Ibis》1894,36(3):447-460
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20.
Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine.  相似文献   

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