首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
This study concerns the Guedmiwa Berber population living in the Azegour Valley, at an altitude of 2000m on the northern slopes of the western range of the Haut-Atlas mountains. The reproductive behaviour of 506 Guedmiwa Berber families shows a rather elevated fertility which seems influenced at the same time by the socio-familial organisation and by the economic resources at the disposition of the family.  相似文献   

5.
This paper is intended as an investigation of the biogeographic characteristics of insect faunas of the seven islands in West Coastal of Incheon, Korea, using quantitative analysis. The faunal similarity is examined using the Bray & Curtis similarity. The obtained similarity value matrix was examined by a cluster analysis using UPGMA method. The number and the distribution records of each species in the areas are 1,001 species of insects belonging to 12 orders from the seven investigated islands. Among above seven islands, Seokmodo has the highest number of species, 497 species, while Yeonpyeongdo has the lowest, 136 species. The species composition of insects reported in Ganghwado was 309 species under seven orders. The similarity values between seven localities investigated range from 24.907(Gyodongdo to Yeonpyeongdo) to 49.899(Baengnyeongdo to Ganghwado). That is, the species composition of Baengnyeongdo(47.90%) was similar to that of Ganghwado, while that of Yeonpyeongdo(25.28%) was different from that. The cluster analysis using a similarity index shows that all the islands of these areas can be divided into 3 groups at the level of 30.97%.  相似文献   

6.
The site of Ahl al Oughlam near Casablanca, Morocco, dated to ca. 2·5 Ma, has yielded a good sample of Theropithecus atlanticus (Thomas, 1884), a North African late Pliocene species previously known only by its holotype, a lower molar from Algeria. Theropithecus atlanticus, which can now be much better defined, is clearly distinct from other species of the genus, which is thus more diverse than previously thought. The mandible of T. atlanticus has a very characteristic deep and long post-molar sulcus and a deep and well excavated supra-lateral triangular depression of the ramus, with a sharp postero-inferior ridge. The upper and lower canines are rather large but low. The male P3is very wide, with well developed posterior crests; the P4is rounded, with a large talonid and weak notches and clefts. Median lingual notches of the lower molars form an acute angle. Although our incomplete knowledge of T. atlanticus precludes a detailed phylogenetic analysis, we suggest that it arose by clado-genesis from the T. dartiT. oswaldi lineage; it is replaced by the latter species in the Pleistocene.Le gisement de Ahl al Oughlam près de Casablanca (Maroc), daté d'environ 2,5 Ma, a livré une belle collection deTheropithecus atlanticus (Thomas, 1884), espèce du Pliocène supérieur nord-africain qui n'était jusque là connue que par son holotype, une molaire inférieure d'Algérie. T. atlanticus, qui peut maintenant être bien mieux défini, se distingue bien des autres espèces du genre, dont la diversité est ainsi accrue. La mandibule de T. atlanticus est très caractéristique par son espace rétro-molaire vaste et profond, et sa dépression supra-latérale de la branche montante également très profonde, avec un rebord inférieur aigu. Les canines supérieures et inférieures sont grosses mais basses. La P3mâle est très large, avec des crêtes postérieures très développées; la P4est arrondie, avec un grand talonide et des sillons peu profonds. Sur les molaires inférieures, le débouché de la vallée médiane forme un angle aigu. Bien que notre connaissance imparfaite de T. atlanticus interdise une analyse phylétique détaillée, nous suggérons une dérivation par cladogenèse à partir de la lignée T. dartiT. oswaldi; cette dernière espèce le remplace au Pléistocène.  相似文献   

7.
奶牛和肉牛6个STR基因座遗传多态性研究   总被引:6,自引:2,他引:6  
贾名威  杨利国  管峰  陆汉希  金穗华 《遗传》2004,26(3):309-314
利用PCR技术和复合电泳银染技术检测奶牛和肉牛BM2113、BM1862、BMc701、BM2934、TGLA122、BM720等6个STR基因座的多态性分布,并计算该6个基因座的基因频率(P_i)、个体鉴别力(DP)、杂合度(H)、多态信息含量(PIC)、和非父排除概率(PE)。结果显示:6个STR基因座的基因型分布符合Hardy-Weinberg平衡,奶牛中6个STR基因座中BM2113基因座的DP、H和PIC最高,TGLA122基因座的PE最高。6个STR基因座的累积个体鉴别力(CDP)为0.99997,累积非父排除能力(CPE)为0.98827。肉牛中6个STR基因座中BM1862基因座的DP、H、PIC、PE都是最高,6个STR基因座的累积个体鉴别力(CDP)为0.99999,累积非父排除能力(CPE)为0.99578。结果表明,6个STR基因座可用于牛的遗传连锁分析、个体识别和亲子鉴定等研究领域。  相似文献   

8.
9.
董靓  张米娜 《生物信息学》2018,25(10):32-37
自然河流经过人工水网重塑与城市产生紧密联系,促进了沿岸城市功能区域的生长,形成了以水为中心的具有独特风貌的沿岸景观。以六朝(222—589年)和明代(1368—1644年)的秦淮河水系为研究对象,通过图解分析梳理其沿岸景观的要素构成、分布特征,包括桥梁、里坊、市肆、楼馆、文教建筑等功能建置,皇家园林、私家园林、寺观园林等园林景观和表现公共景观的景观文化3个层面;通过比较分析探究其背后的形成原因,把握水城共生的互动关系,以期对“人与自然和谐共生”的生态文明建设、城市河流景观资源的可持续发展提供借鉴  相似文献   

10.
自然河流经过人工水网重塑与城市产生紧密联系,促进了沿岸城市功能区域的生长,形成了以水为中心的具有独特风貌的沿岸景观。以六朝(222—589年)和明代(1368—1644年)的秦淮河水系为研究对象,通过图解分析梳理其沿岸景观的要素构成、分布特征,包括桥梁、里坊、市肆、楼馆、文教建筑等功能建置,皇家园林、私家园林、寺观园林等园林景观和表现公共景观的景观文化3个层面;通过比较分析探究其背后的形成原因,把握水城共生的互动关系,以期对“人与自然和谐共生”的生态文明建设、城市河流景观资源的可持续发展提供借鉴  相似文献   

11.
12.
Abstract Symbiotic experiments in the glasshouse demonstrated that two species of sulla, Hedysarum coronarium and Hedysarum flexuosum , grown in Morocco were mutually incompatible in their requirements for effectively nitrogen-fixing strains of rhizobia: nitrogen-fixing Rhizobium strains isolated from H. coronarium nodulated H. flexuosum but did not fix nitrogen, conversely strains from H. flexuosum were ineffective for H. coronarium . The agronic implications are discussed.  相似文献   

13.
两湖平原六个湖泊水生植物多样性的比较研究   总被引:6,自引:0,他引:6  
为了揭示人为干扰对淡水湖泊水生植物多样性的影响 ,本文采用断面法 ,应用全球定位系统 (GPS)技术与地理信息系统 (GIS)技术 ,比较研究了所受干扰强度各不相同的两湖平原的白莲湖、海口湖 (轻度干扰 )、长湖、西凉湖 (较强度干扰 )、大通湖与武山湖 (重度干扰 )水生植物多样性的现状及其 2 0年来的变化 ,并探讨了人为干扰强度与植物多样性丰富程度及丧失程度间的关系。主要结论是 (1) 2 0 0 1年白莲湖、海口湖、长湖、西凉湖、大通湖与武山湖各分布有水生植物 6 9、 6 7、 98、 77、 5 6和 38种 ,6个湖泊各有水生植物群丛类型 14、 14、 14、 13、 6和 0个 ,植被覆盖率分别为 10 0 %、 96 18%、 6 5 32 %、 6 1 18%、10 6 0 %和 0 % ,全湖平均单位面积生物量分别是 2 2 31g m2 、 2 718g m2 、 1816g m2 、 14 71g m2 、2 5 6g m2 和 0g m2 。 (2 ) 2 0年来 ,6个湖泊各有 1、 1、 6、 7、 9和 2 9种水生植物消失 ,消失的水生植物群丛类型数目分别是 1、 1、 4、 4、 5和 6个 ,水生植被覆盖率分别下降了0 %、 3 82 %、 32 85 %、 37 80 %、 5 9 4 0 %和 91 0 0 %。 (3)多样性丰富程度的现状是白莲湖、海口湖 >长湖、西凉湖 >大通湖、武山湖 ,丰富程度与所受干扰强度成负相关关系 ;多样性丧失程度与所  相似文献   

14.
Two personality testing forms, the Eysenck Personality Inventory Form A and the Cattell Self Analysis Form, were completed on 471 hospital patients who fell within the general diagnostic range of asthma, bronchitis, or both. Respiratory diagnoses were based on the standard M.R.C. questionary. All categories of patients showed a tendency towards neuroticism, anxiety, and introversion, and the scores were slightly higher for bronchitics than for asthmatics. Neuroticism and anxiety increased with increasing respiratory disability. Variations in these scores with age of onset of symptoms and length of history were small.  相似文献   

15.
16.
We report the existence, in Torpedo marmorata tissues, of a cholinesterase species (sensitive to 10(-5) M eserine) that differs from acetylcholinesterase (AChE, EC 3.1.1.7) in several respects: (a) The enzyme hydrolyzes butyrylthiocholine (BuSCh) at about 30% of the rate at which it hydrolyzes acetylthiocholine (AcSCh), whereas Torpedo AChE does not show any activity on BuSCh. (b) It is not inhibited by 10(-5) M BW 284C51, but rapidly inactivated by 10(-8) M diisopropylfluorophosphonate. (c) It does not exhibit inhibition by excess substrate up to 5 X 10(-3) M AcSCh. (d) It does not cross-react with anti-AChE antibodies raised against purified Torpedo AChE. This enzyme is obviously homologous to the "nonspecific" or pseudocholinesterase (pseudo-ChE, EC 3.1.1.8) that exists in other species, although it is closer to "true" AChE than classic pseudo-ChE in several respects. Thus, it shows the highest Vmax with acetyl-, and not propionyl- or butyrylthiocholine, and it is not specifically sensitive to ethopropazine. Pseudo-ChE is apparently absent from the electric organs, but represents the only cholinesterase species in the heart ventricle. Pseudo-ChE and AChE coexist in the spinal cord and in blood plasma, where they contribute to AcSCh hydrolysis in comparable proportions. Pseudo-ChE exists in several molecular forms, including collagen-tailed forms, which can be considered as homologous to those of AChE. In the heart the major component of pseudo-ChE appears to be a soluble monomeric form (G1). This form is inactivated by Triton X-100 within days.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

17.
18.
In order to reveal the effects of human disturbance on aquatic plant diversity in freshwater lakes,the species and community diversity of aquatic plant,and their long term changes in six freshwater lakes of Dongting Poyang District (Lake Bailian and Haikou under lightly disturbance,Changhu and Xiliang under heavy disturbance,Datong and Wushan under very heavy disturbance) were comparatively studied by means of Transect Sampling Method,Global Position System Technique (GPS) and Geographical Information System Technique(GIS).The main results are as follows:(1)It was found that Lake Bailian,Haikou,Changhu,Xiliang,Datong and Wushan contained 69,67,98,77,56,38 aquatic plant species and 14,14,14,13,6,0 associations,respectively in 2001.Their coverages reached to 100%,9618%,6532%,6118%,1060%,0% and mean biomass 2231?g/m2,2718?g/m2,1816?g/m2,1471?g/m2,256?g/m2,0?g/m2 (fresh weight),respectively.(2)As compared with the data obtaining from the surveys in 1980 to 1982,1,1,6,7,9 and 29 species,and 1,1,4,4,5 and 6 associations of aquatic plant disappeared from the six lakes respectively in the last twenty years.Their respective vegetation coverage decreased by 0%,382%,3285%,3780%,594% and 9100%.(3)According to the statistics of plant species,there appeared a gradient as follows:Lake Bailian,Haikou>Changhu,Xiliang>Datong,Wushan.Their different current situations clearly reflected that in the past twenty years thery had suffered from human disturbance in different degrees.(4)The main biological mechanism for the loss of aquatic plants is that human disturbance destroyed the rhizomes and the dormant kuds can't formed.  相似文献   

19.
目的:研究海南汉族人群MICB等位基因的多态性与乳腺癌易感性之间的关联性。方法:采用PCRSSP(PCR sequence-specific primers)和PCR-SBT(PCR sequence-based typing)方法对样本MICB等位基因的多态性进行检测。结果:乳腺癌患者中检出14种MICB等位基因;和对照组相比较,MICB*002和MICB*014等位基因在乳腺癌患者组分布频率较少,MICB*002和MICB*014等位基因可能对乳腺癌不易感(MICB*002:OR=0.31,95%CI:0.19-0.51,Pc0.05;MICB*014:OR=0.32,95%CI:0.17-0.60,Pc0.05)。MICB*016和MICB*003等位基因在乳腺癌患者组分布较多;MICB*016和MICB*003等位基因可能对乳腺癌易感(MICB*016:OR=10.68,95%CI:2.52-45.28,Pc0.05;MICB*003:OR=3.57,95%CI:1.34-9.49,Pc0.05);MICB*002/002和MICB*014/014基因型可能对乳腺癌不易感(MICB*002/002:OR=0.12,95%CI:0.04-0.36,Pc0.05;MICB*014/014:OR=0.30,95%CI:0.10-0.89,Pc0.05)。结论:MICB等位基因的多态性与乳腺癌的易感性之间存在关联性。  相似文献   

20.
目的:研究海南汉族人群MICB等位基因的多态性与肺癌易感性之间的关联性。方法:采用PCR-SSP(PCR sequence-specific primers)和PCR-SBT(PCR sequence-based typing)方法对样本MICB等位基因的多态性进行检测。结果:肺癌患者中检出14种MICB等位基因;和对照组相比较,MICB*00502等位基因在肺癌患者组分布频率较少(43.5%vs 57.8%),MICB*016等位基因在肺癌患者组分布较多(5.9%vs 0.6%);MICB*016等位基因可能对肺癌易感(OR=11.19,95%CI:2.59-48.24,Pc0.05);MICB*00502等位基因可能对肺癌不易感(MICB*00502:OR=0.56,95%CI:0.42-0.76,Pc0.05)。结论:MICB等位基因的多态性与肺癌的易感性之间存在关联性。  相似文献   

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