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1.
对人工饲养条件下褐马鸡繁育的关键性技术进行了研究,并利用分组对比繁育的方法对不同的性比.与受精率、出雏率和成活率之间的关系进行了探讨,所取得的经验对保护国家珍稀鸟类具有积极意义.  相似文献   

2.
基于褐马鸡(Crossoptilon mantchuricum)西部种群的126个分布数据及25个环境变量,利用MaxEnt模型对其适宜生境及主要影响因子进行定量分析。结果显示,模型的预测结果达优秀水平。最干季平均温度、最干月降水量、最冷季平均降水量、最热月极高温度和距道路的距离是主要影响因子,其阈值分别为-6.0~-4.3℃、4.90~5.75 mm、15.3~16.8 mm、23.0~26.3℃和0~54 m。褐马鸡西部种群适宜栖息地集中在陕西省黄龙县、宜川县、洛川县和韩城市。从各县(市)不同适宜等级面积而言,适宜栖息地面积由大到小依次为黄龙县韩城市宜川县洛川县。目前在陕西省黄龙山建立了2个与褐马鸡有关的国家级自然保护区,但褐马鸡最适宜栖息地和中等适宜栖息地已超出保护区范围,建议当地政府或林业管理部门调整保护区的规划或者加强这些超出区域的监测力度。  相似文献   

3.
幽门螺杆菌研究进展   总被引:1,自引:0,他引:1  
幽门螺杆菌(Helicobacterpylori)是1982年Warren和Marshall等人[1]在培养人体胃粘膜活检组织样品时发现的,当时名为幽门弯曲杆菌(Campylobacterpylori);以后随着各方面研究的深入,Goodwin等[2]1989年建立了螺杆菌属(Helicobacter),才将C.Pylori正式命名为H.pylori.H.pylori是人类慢性活动性胃炎(B型胃炎)及胃,十二指肠溃疡的重要病原菌,并且是肠型胃癌的诱发因素之一.因而,引起世界范围内对H.pylor…  相似文献   

4.
反馈     
巴西来信 我是巴西自然保护基金会的技术主任,刚刚收到你们2000年1-6月的《产业与环境》第23卷第1-2期.由于我与巴西东北部地区的海牛计划关系密切(我实际上负责在Alagoas州建立海牛基地),所以请允许我指出93页上的一处印刷错误:在正在被喂食的小海牛图片上方应该是“Trichechus inunguis(淡水生物)”,而不是“Trichechus munguis”…… 谢谢你们在你们的刊物中提到这些奇妙的动物.我觉得它们非常可爱,它们需要它们能从国际社会得到的所有帮助. 希望你们象前些年那样…  相似文献   

5.
苏云金芽孢杆菌无质粒突变株BMB171的转化和表达性能   总被引:4,自引:1,他引:3  
研究了苏云金芽孢杆菌无质粒突变株BMB171的转化性能和表达cry1Ac和cry1Ca基因的性能.用pHT3101、pBMB305、pBMB1736、pBMB671、pBTL1和pHV1249等6种外源质粒电转化无质粒突变株BMB171,其转化频率分别是Bt4Q7、Bt4D10和Bti.IPS.78/11等3种常用受体菌相应最高转化频率的1000、6.7、12.5、66.7、3500和2倍,其每μgDNA的最高转化子数达107.导入BMB171的外源质粒的稳定性与其复制子类型和质粒大小有关.无质粒突变株BMB171表达cry1Ac基因的表达量高于对照受体菌Bt4Q7,略低于Bt4D10和Bti.IPS.78/11,而BMB171表达cry1Ca基因的表达量高于这3种受体菌;对小菜蛾3龄幼虫和甜菜夜蛾初孵幼虫的毒力测定结果表明,BMB171表达cry1Ac基因的杀虫毒力高于Bt4Q7和Bt4D10,略低于Bti.IPS.78/1;而表达cry1Ca基因的毒力高于这3种受体菌  相似文献   

6.
芒苞草的化学成分   总被引:4,自引:0,他引:4  
从芒包草(Acanthochlamys bracteata P. C. Kao)全草的甲醇撮物中分离出6个晶体,经波谱分析和与标准品对照,将它们分别鉴定为:豆甾醇(Ⅰ)、豆甾醇葡萄糖甙(Ⅱ)、7α-羟基豆甾醇(Ⅲa)和7β-羟基豆甾醇(Ⅲb)的混晶、棕榈酸(Ⅳ)、euscaphic acid(Ⅴ)、和槲皮素-3’,4’7-三甲醚(Ⅵ)。实验表明甾醇类化合物是该植物的主要次主代谢产物。这是该单种属科  相似文献   

7.
网址要览     
气候变化知识网络www.cckn.net 气候变化知识网络是由来自发展中国家、转型国家和发达国家的12个以上的组织组成的联盟。网络的目的是通过在京都机制、适应气候变化和技术转让等问题上的合作研究和行动帮助建立一个更有效的、可持续的合理的气候变化体制;帮助发展中国家和发达国家建立更好地理解和处理气候变化问题的能力;帮助进行网络内部和网络之外的信息和知识交流.欲知详情,请联系:Victoria Kellett,Project Man-ager,International Institute for Sus…  相似文献   

8.
EoNPV的限制性酶切图谱及polyhedrin基因和egt基因的定位   总被引:1,自引:0,他引:1  
用8种限制性内切酶酶解茶尺蠖Ectropisobliqua核型多角体病毒(EoNPV)基因组DNA,获得大于0.88kb的片段数分别为7、38、19、17、16、9、32和14.由此统计,基因组平均大小大于118.5kb,即Mr约大于78.6×106.用BmNPV的多角体蛋白(ph)基因和AcMNPV的egt基因为探针,应用Southern杂交方法,将EoNPV的ph基因定位于BamHIA、ClaID、EcoRIM、EcoRVL、HindⅢF、PstIA、SalIH和XhoIB片段上,将egt基因定位于BamHIA、ClaIl、EcoRIK、EcoRVA、HindⅢH、PstIA、SalIB、XhoII片段上.通过克隆和酶切鉴定EcoRIM和EcoRVL片段,测定ph基因部分序列,并以EcoRIM为探针对基因组酶切印迹进行杂交,制作了EoNPVph基因和egt基因区的酶切图谱,推定egt基因保守区位于ph基因上游约4.55kb处.  相似文献   

9.
电话机的寿命周期设计CarloVezzoli,CIR.IS-UR.PS,跨系研究中心,“为环境可持续性而革新”研究组,ProductandServicesDITecDept.,PolytechnicUniversityofMilan,ViaBonar...  相似文献   

10.
网址要览     
中国加拿大清洁生产合作项目www.chinacp.com中国加拿大清洁生产合作项目是一个英文和中文网址,是为那些对中国清洁生产的实施感兴趣的人们设计的.该网址的中文部分是为中国正在实施清洁生产的工厂及其它组织设计的.由中国加拿大清洁生产合作项目创办并得到加拿大国际发展局资助的这个网址,重点是该项目,但也提供下列信息:清洁生产和ISO14000的更普遍问题,中国的其它清洁生产活动,和与加拿大及国际上有关的清洁生产、污染预防和ISO14000网址的连接键.联系地址:KennethParent,…  相似文献   

11.
本研究旨在探讨BDE 209长期暴露对出生后不同发育阶段子鼠血液系统的影响。将75只雌性昆明小鼠随机分为对照组、低剂量组(1.5 mg·kg-1·d-1)和高剂量组(225 mg·kg-1·d-1)。BDE 209暴露10 d后,将雌鼠与雄鼠合笼。选取怀孕时间相近(相差不过2 d)的10只孕鼠持续染毒直至自然分娩。出生后子鼠在哺乳期通过母乳染毒,断乳后则按照与母鼠相同的方式进行染毒,并在不同时间点进行外周血常规、外周血形态学、骨髓细胞形态学、骨髓细胞染色体组型和数目分析。血常规结果显示,低、高剂量BDE 209暴露对出生后不同发育阶段子鼠的白细胞计数没有影响,即白细胞、中性粒细胞、淋巴细胞及单核细胞的数量均无显著变化(P0.05);红细胞系统检查显示一定性别差异,即低剂量和高剂量BDE 209染毒的雄性小鼠在PND30出现红细胞(RBC)(P0.05)、血红蛋白(Hb)(P0.05或P0.01)及红细胞压积(P0.05或P0.01)的显著降低;而雌性小鼠只在PND 30出现红细胞压积的降低(P0.05);在PND 30,高剂量暴露组的雌性及雄性小鼠,低剂量暴露组的雌性小鼠均出现血小板计数的显著降低(P0.05或P0.01);而PND 60、PND 90的实验组血小板均未观察到显著改变(P0.05)。外周血形态学检查表明,低剂量组在PND 30、PND 60,及高剂量组在PND 90检测到典型异常结果多表现为白细胞数的增多。而低剂量组在PND 90检测到的典型异常结果多表现为异型深染淋巴细胞(P0.05)。骨髓形态学检测表明,低剂量组子代雄性及雌性小鼠在PND 60、PND 90骨髓涂片可检测到骨髓细胞的异常结果,表现为骨髓增生活跃,高剂量组雄性小鼠在PND 90观察到3例异常涂片,表现为骨髓增生异常(P0.05)。研究结果表明,BDE 209长期暴露可能导致出生子代外周血和骨髓的毒性,提示具有血液系统发育毒性。  相似文献   

12.
Variations in organ indices, organic levels, organic and caloric contents of the gonads of the brooding echinoid Abatus cordatus (Verrill), collected in the Morbihan Gulf (49°30′S; 70°E) were studied over a 1 yr period (March 1978 to January 1979). In both sexes, a clear annual cycle was discernable for organ indices, and for organic and caloric contents. In contrast, the protein levels in the gonads varied moderately, while the levels of lipid and carbohydrate remained almost constant. This peculiarity sets A. cordatus apart from nearly all other echinoids characterized by an annual reproductive cycle. The male and female gonad indices change synchronously. The gonad indices double during maturation, reflecting variations in the germinal tissue. In both sexes, the maximal gonad index (at the end of March) coincides with the onset of the spawning season. The average male gonad index is 50% higher than that of the female. This difference is related to the restriction of coelomic space in the female due to development of the brood pouches. At maturity, the lipid and carbohydrate levels in the ovary are 2.8 and 2.1 times greater, respectively, than the levels in the testis, the latter having a 25% higher protein level. This disparity in organic levels reflects mainly the differences in germinal tissue composition. The female reproductive effort is higher than that of the male. The spawn energy output of a standard individual is 200 cal for a male and 228 cal for a female. The unusually lower gonad index of the female is compensated for by higher lipid and carbohydrate levels, giving the ovary a 40% higher calorific value.  相似文献   

13.
为了研究低剂量的全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)对水生生物的内分泌干扰效应和作用机制,考察了PFOS对斑马鱼(Brachydanio rerio)血浆和组织匀浆中卵黄蛋白原(vitellogenin,VTG)含量的影响。将雄性和雌性斑马鱼分别暴露于0.1、1、10和100μg·L-1的PFOS中进行21d毒性实验,染毒结束后分别检测雄鱼和雌鱼的血浆、头尾组织匀浆液和全鱼匀浆液中的VTG含量。结果显示:(1)PFOS暴露可引起斑马鱼血浆、全鱼和头尾匀浆液中VTG含量的升高,VTG含量的排序为雌鱼(血浆>>全鱼匀浆>头尾匀浆)>>雄鱼(血浆>全鱼匀浆>>头尾匀浆);(2)PFOS暴露所引起的雄鱼血浆和头尾匀浆中VTG含量的升高与剂量呈负相关关系,暴露浓度为0.1μg·L-1时与对照组相比有显著性差异(p<0.05);(3)雌鱼血浆和头尾匀浆中VTG含量的升高与剂量呈倒U型曲线关系,暴露浓度为10μg·L-1时与对照组相比有显著性差异(p<0.05);(4)雄鱼和雌鱼的全鱼匀浆液中的VTG含量与对照组相比均无显著性差异。研究结果表明,PFOS暴露对斑马鱼的内分泌干扰作用明显,其毒性作用机制可能是类雌激素效应,血液和头尾匀浆液中VTG含量能够作为PFOS内分泌干扰效应评价的敏感生物标志物,但响应曲线可能因性别和组织部位的不同有所差异。  相似文献   

14.
赤霉酸是目前国内外使用极其广泛的一种植物生长调节剂,但是针对其发育毒性的数据依然较少。本文探讨了赤霉酸暴露对SD大鼠青春期发育的影响。参考国内外环境内分泌干扰物危害的评价方法,将144只初断乳SD大鼠按体重随机分为4组,分别为对照组和1、10、100 mg·kg-1bw剂量组,采用经口灌胃方式对雄鼠连续染毒28 d,雌鼠连续染毒21 d。暴露结束后检测大鼠的体重、食物利用率、雄鼠包皮分离时间/雌鼠阴道开口时间、血清生化指标、脏器系数及组织病理学的变化。研究结果表明,与对照组相比,仅10和100 mg·kg-1bw剂量组雄鼠的肌酐水平显著升高(P<0.01),100 mg·kg-1bw剂量组雌鼠谷丙转氨酶水平有显著升高(P<0.01)。而与对照组相比,所有剂量组均未观察到大鼠的体重、食物利用率、雄鼠包皮分离时间/雌鼠阴道开口时间、脏器系数等指标有显著性差异的改变(P>0.05),组织病理学结果亦显示大鼠重要器官无损害性改变。因此,在本试验给予的剂量范围内赤霉酸染毒不会对SD大鼠青春期发育产生显著影响。  相似文献   

15.
以北京油松(Pinus tabuliformis)人工林为研究对象,采用独立样本T检验、冗余分析等方法,分析重度火烧1年后林下植被(灌木层和草本层)的物种多样性、叶功能性状及其与土壤因子的关系.结果显示:(1)与对照样地相比,重度火烧后灌木层物种丰富度指数极显著降低(P <0.01),但Shannon指数、Simpson指数以及Pielou指数虽呈下降趋势但未达显著水平(P> 0.05);草本层除Pielou指数外,各物种多样性指数均显著增加(P <0.05).(2)重度火烧样地灌木层和草本层的叶厚度(LT)、叶干物质含量(LDMC)、叶碳含量(LCC)、叶磷含量(LPC)均高于对照样地,而比叶面积(SLA)、叶氮含量(LNC)、叶片氮磷比(N:P)、叶绿素含量(CHL)低于对照样地,除灌木层LPC和N:P及草本层SLA、LCC和LPC外,其他各叶功能性状在火烧与对照间差异均达显著水平.对于不同生活型而言,对照样地的LDMC、LNC、LCC、CHL存在显著差异,而在重度火烧后差异不显著;LT、SLA在重度火烧和对照样地上均呈现显著差异;而LPC、N:P在重度火烧与对照样地上均无显著差异.(3)重度火烧后1年,灌木层和草本层的叶功能性状均仅与土壤含水率、容重和非毛管孔隙度密切相关.本研究表明在油松人工林重度火烧后1年,灌木层物种多样性降低,而草本层物种多样性增加,灌草层的各叶功能性状主要受土壤物理性质的影响呈现不同的变化规律.(图4参45)  相似文献   

16.
Summary Experiments were designed to determine the effects of male pigmentation patterns on female choice in guppies. When presented with a series of variably-colored males, females of different genetic strain consistently exhibited similar preferences (Tables 1 and 2), preferring those males with the greatest development of both carotenoid and iridescent pigments (Table 3). A partial rank correlation analysis of pigments of males indicates positive correlations between the iridescent and carotenoid pigments and also between melanins and showiness (Table 4). Only when either the carotenoid or iridescent pigments were held constant was there any effect of the other pigments on the ranking order of males by the females. Other pigments appear to be relatively unimportant in influencing female choice of males. These results indicate that females discriminate among males on the basis of color and that females of different strains prefer the same male colors rather than those characteristics of males of their own strain. The results support those models of sexual selection that hold that sexually selected traits honestly advertise the phenotypic and genetic qualities of males; they do not support models of runaway selection for particular male traits, such as first proposed by Fisher (1930).  相似文献   

17.
黄精多糖对果蝇寿命的影响   总被引:30,自引:1,他引:30  
水提法从黄精属的一种(Pdygonatum sp.)分离得到一种含糖为96.25%的黄精多糖(Polygonatum polysaccharide,简称PP)。PP经UV-240紫外分光光度计扫描,其特征吸收率为200nm,无蛋白质(280nm)和核酸(260mn)的特征吸收峰。浓度分别为0.05%、0.5%、2%的PP哺养果蝇(60d)的实验结果表明:三种浓度组两性果蝇的平均寿命和最高寿命均明显  相似文献   

18.
Although female animals tend to be choosier than males in selecting mates, sexual selection theory predicts that males should also be choosy when female fecundity varies. Reproductive success among female spotted hyenas varies greatly with social rank. Our goals were therefore to determine whether male hyenas preferentially associate with high-ranking females, and whether male preferences are affected by female reproductive state. Interactions between adult males and females were observed intensively, and association indices calculated for all male-female pairs, over a 7-year period in one population of free-living hyenas. Males initiated most affiliative interactions with females, and males associated most closely with females that were likeliest to be fertile. High- and middle-ranking males associated most closely with high-ranking females, but low-ranking males associated equally closely with females in all rank categories. We used molecular markers to determine the paternity of cubs born during the study period, and found that sires associated more closely with the mothers of those cubs than did non-sires, particularly during the last months before conception. These association data indicate that male spotted hyenas do indeed exhibit selective mate choice, and that they prefer females likeliest to maximize male reproductive success.  相似文献   

19.
Theory predicts that frequent dyadic association should promote cooperation through kin selection or social tolerance. Here we test the hypothesis that sex differences in the strength and stability of association preferences among free-ranging chimpanzees conform to sex differences in cooperative behavior. Using long-term data from the Kanyawara chimpanzee (Pan troglodytes schweinfurthii) community (Kibale National Park, Uganda), we calculated indices of intra-sexual dyadic association over a 10-year period. We found that (1) male–male dyads had significantly stronger association indices than female–female dyads, (2) the pattern of association preferences in both sexes changed little over the entire study period, and (3) when comparing periods with different alpha males, changes in association strength were more frequent among males. These results demonstrate that both the strength and stability of association patterns are important components of social relationships. Male chimpanzees, which are characterized by frequent cooperation, had association preferences that were both strong and stable, suggesting that forming long-term bonds is an important dominance strategy. However, the fact that male association patterns were sensitive to upheaval in the male dominance hierarchy suggests that males also take advantage of a changing social climate when choosing association partners. By contrast, the overall strength of female associations was relatively weak. Female association preferences were equally stable as males’; however, this reflected a dyad’s tendency to be found in the same party rather than to associate closely within that party. Therefore, in this community, female association patterns appear to be more a consequence of individual ranging behavior rather than a correlate of cooperation.  相似文献   

20.
Courtship and body condition of male two-spotted gobies (Gobiusculus flavescens) harbouring naturally acquired microsporidian infections were compared with those of microsporidian-free males under standardized conditions in the lab. Although parasite infection had no apparent effect on individual condition, it significantly affected male courtship intensity. This effect, however, was affected by the intensity of the female courtship. Our study is one of the first to demonstrate a sub-lethal behavioural effect of a microsporidian parasite that could negatively affect the reproductive success of infected individuals. Our results also suggest that secondary sexual traits like courtship may be more sensitive to moderately detrimental effects of parasite infection than classical condition indices.  相似文献   

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