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1.
本实验用人重组r-干扰素(rhu-IFN)作用HEP-2细胞后HLA-DR抗原和增殖细胞核抗原(PCNA)表达的检测来探讨r-干扰素对HEP-2细胞HLA-DR抗原表达诱导作用及体外抗增殖活性。用单克隆抗体CR3/43(抗HLA-DR)和Ki-67(抗PCNA)。以链霉素一生物素技术(LSAB)检测HEP-2细胞HLA-DR抗原和PCNA表达,结果显示:r-IEN诱导HLA-DR抗原和抑制PCNA表达其强弱与r-IFN剂量有关。资料提示:r-IFN不仅对HEP-2细胞有细胞毒作用,同时能调节其细胞膜特性,因而在喉癌的治疗中是有效的。  相似文献   

2.
中国革螨二新纪录种(蜱螨亚纲:厉螨科、巨螫螨科)TWONEWLYRECORDEDSPECIESOFGAMASINAFROMCHINA(ACARI:LAELAPIDAE,MACROCHELIDAE)¥YERUI-YU(XinjiangInstitute...  相似文献   

3.
被子植物的无融合生殖   总被引:20,自引:4,他引:20  
被子植物的无融合生殖孙敬三刘永胜辛化伟(中国科学院植物研究所,北京100093)APOMIXISINANGIOSPERMSSunJing-san,LiuYong-sheng,XinHua-wei(InstituteofBotany,AcademiaS...  相似文献   

4.
西藏禾本科植物新分类群与新记录种   总被引:1,自引:0,他引:1  
西藏禾本科植物新分类群与新记录种赵南先,李名非(安徽省生物研究所,合肥230031)NEWTAXAANDNEWRECORDINGSPECIESOFGRAMINEAEFROMTIBET¥ZHAONan-Xian;LIMing-Fei(AnhuiInst...  相似文献   

5.
采用荧光分光光度计法检测维甲酸(RA)、1,25(OH)2VD3及佛波酯(PMA)诱导CCL229细胞分化后[Ca2+]i变化,并观察内质网(ER)特异的Ca2+-ATPase抑制剂Thapsigargin(TG)、IP3受体抑制剂Heparin对RA诱导[Ca2+]i变化的影响,从而探讨RA诱导[Ca2+]i变化与ER的关系。结果显示:RA和1,25(OH)2VD3在数秒内引起[Ca2+]i显著升高。在EGTA和Verapamil预处理细胞条件下,TG不能抑制RA引起Ca2+从细胞内钙池中外流,RA作用后TG仍能升高[Ca2+]i。另外,Heparin也不能完全抑制RA升高[Ca2+]i。提示RA诱导大肠癌细胞升高[Ca2+]i可能通过ER上IP3敏感性和非敏感性钙池,亦可能细胞内存在除ER外对RA敏感的钙池。  相似文献   

6.
有毒铜绿微囊藻M.aeruginosaPCC7820对氨基酸的吸收徐平,曾昭琪(南京大学生物系,210008)UPTAKEOFAMINOACIDSBYTOXICMICROCYSTISAERUGINOSAPCC7820¥XuPingandTsengCh...  相似文献   

7.
高成芝   《广西植物》1994,14(1):20-22
广西獐牙菜属一新种高成芝(广西中医药研究所,南宁530022)ANEWSPECIESOFSWERTIAFROMGUANGXI¥GaoChengzhi(GuangxiInstituteofTraditionalMedical&Pharmaceutica...  相似文献   

8.
沙文兰   《广西植物》1994,(1):23-24
广西狸尾豆属一新种沙文兰(广西天然药物研究中心,南宁530022)关键词广西狸尾豆ANEWSPECIESOFURARIAFROMGUANGXl¥shaWenlan(GuangxiResearchCentreofNaturalMateriaMedica...  相似文献   

9.
沙文兰   《广西植物》1994,14(1):23-24
广西狸尾豆属一新种沙文兰(广西天然药物研究中心,南宁530022)关键词广西狸尾豆ANEWSPECIESOFURARIAFROMGUANGXl¥shaWenlan(GuangxiResearchCentreofNaturalMateriaMedica...  相似文献   

10.
东北鼢鼠种群生长指标的主分量分析   总被引:2,自引:0,他引:2  
东北鼢鼠种群生长指标的主分量分析PRINCIPALCOMPONENTANALYSISOFGROWTHINDEXOFPOPULATIONFORMANCHURIANZOKOR(MYOPALAXPSILURAS)东北鼢鼠(Myopalaxpsiluras...  相似文献   

11.
为了更好地了解荒漠河岸林植被动态与生物多样性维持机制,于塔里木河干流源头荒漠河岸林内建立6个1 hm2样地,对群落物种组成、数量特征和空间格局等进行综合分析。结果表明,塔河源荒漠河岸林群落结构简单、物种多样性低,共有物种12科15属16种,杨柳科重要值最大(28.97%),是群落优势建群科。取样面积在0.04 hm2时,包括了87.5%的物种;样地内稀有种和偶见种均占所有物种的12.5%。植物区系贫乏,单种科、属多,温带成分占绝对优势,古地中海成分也占有重要地位,具典型温带区系性质。样地内DBH ≥ 1 cm的活木本个体有2497株,灰胡杨多度占92.95%,胸高断面积和重要值最大,在群落中占绝对优势地位。群落内科、属、种的数量随植株高度级的增加而减少,垂直结构层次分明,由乔木层、灌木层和草本层构成。样地内所有树种平均胸径15.57 cm,径级与高度级结构均呈偏正态分布,缺乏高度≤ 2 m的个体,群落更新不良。优势种灰胡杨、胡杨径级结构均呈单峰型,其中胡杨幼树出现断层,灰胡杨幼苗向幼树发展过程中死亡率极高(92.56%),均为衰退型种群。两个优势种空间格局呈聚集分布,不同生境下随径级增大空间分布格局变化不同;且两个优势种在空间上相互排斥而占据不同生境,暗示着种间竞争与生境异质性是影响荒漠河岸林物种空间分布格局和物种共存的重要因素。  相似文献   

12.
基于七姊妹山自然保护区内6 hm~2监测样地多度数据,通过累计经验分布曲线(ECDF)表征该样地内不同生活型功能群的物种-多度分布格局,并采用6种模型对各功能群不同取样尺度物种等级-多度曲线进行拟合并检验其拟合效果,分析多度格局与模型拟合在不同尺度间的差异,探讨其背后的生态学过程与机制。结果表明:(1)各尺度下落叶种比常绿种的物种数多,物种多样性指数更大,但个体数相对较少;不同功能群稀有种比例排序为:落叶种所有种常绿种。(2)6种模型中的断棍模型的拟合效果较差;中大尺度(50 m×50 m、100 m×100 m)上不同生活型树种多度分布能接受的模型较少,除大尺度的常绿树种外,拟合最优模型均为对数正态分布模型,大尺度的常绿树种拟合最优模型为中性模型;小尺度上(20 m×20 m)常绿树种的最优模型为对数正态分布模型,落叶树种最优模型为生态位优先模型,所有树种在小尺度最优模型为Zipf-Mandelbrot模型。研究认为,随着尺度逐渐扩大,中性过程较生态位过程对物种-多度格局的解释力度更大,落叶树种物种多度格局的形成机制较常绿树种更接近于样地所有树种物种-多度格局的形成机制。  相似文献   

13.
塔河源荒漠河岸林群落物种组成、结构与植物区系特征   总被引:1,自引:0,他引:1  
为了更好地了解荒漠河岸林植被动态与生物多样性维持机制,于塔里木河干流源头荒漠河岸林内建立6个1 hm 2样地,对群落物种组成、数量特征和空间格局等进行综合分析。结果表明,塔河源荒漠河岸林群落结构简单、物种多样性低,共有物种12科15属16种,杨柳科重要值最大(28. 97%),是群落优势建群科。取样面积在0. 04 hm 2时,包括了87. 5%的物种;样地内稀有种和偶见种均占所有物种的12. 5%。植物区系贫乏,单种科、属多,温带成分占绝对优势,古地中海成分也占有重要地位,具典型温带区系性质。样地内 DBH ≥ 1 cm 的活木本个体有2497株,灰胡杨多度占92. 95%,胸高断面积和重要值最大,在群落中占绝对优势地位。群落内科、属、种的数量随植株高度级的增加而减少,垂直结构层次分明,由乔木层、灌木层和草本层构成。样地内所有树种平均胸径15. 57 cm,径级与高度级结构均呈偏正态分布,缺乏高度≤ 2 m的个体,群落更新不良。优势种灰胡杨、胡杨径级结构均呈单峰型,其中胡杨幼树出现断层,灰胡杨幼苗向幼树发展过程中死亡率极高(92. 56%),均为衰退型种群。两个优势种空间格局呈聚集分布,不同生境下随径级增大空间分布格局变化不同;且两个优势种在空间上相互排斥而占据不同生境,暗示着种间竞争与生境异质性是影响荒漠河岸林物种空间分布格局和物种共存的重要因素。  相似文献   

14.
Comparison of the diversity and community structure of Coleoptera (Passalidae) collected in Los Tuxtlas, Veracruz, Mexico, in primary and secondary tropical forest has been carried out. The saproxylophagous beetles studied can be differentiated according to their presence in three distinct microhabitats of rotting logs: underbark, sapwood—heartwood and microhabitat generalists. Over the 2-year study period, 12 passalid species were recorded (six Passalini and six Proculini) represented by a total of 2971 individuals, collected from 234 rotting logs. The rarefaction method, the lognormal species—abundance relationship, and the nonparametric jackknife method were used to compare species richness between the habitats. The data were also fitted to log series, truncated lognormal, geometric, and broken-stick species abundance models to detect changes in community structure. The community composition of Passalidae in Los Tuxtlas did not differ ostensibly between the primary and secondary forests. Neither the mean number of individuals nor the biomass per log differed significantly. Furthermore, there were no significant differences between the two habitats in terms of the number of underbark, sapwood/heartwood, and microhabitat generalist species. Different richness estimators indicated that the primary forest community is only slightly richer. The slight decrease in richness of the secondary forest is related to a decrease in dominance by certain species, as well as to a more balanced abundance distribution, which is adequately described by the broken-stick model. Complementary explanations for this pattern may be: (1) that logging reduces the abundance of dominant species, thus preventing competitive exclusion in the secondary forest; and (2) that passalid diversity is not regulated by the diversity of tree species.  相似文献   

15.
Aim To assess short‐term variability in the community composition and community structure of tintinnid ciliates, herbivores of the microzooplankton. Location North‐west Mediterranean Sea. Methods We sampled on 18 dates over a 4‐week period in 2004 at an open‐water site. Species were classified as ‘core species’, found on every date, or ‘occasional species’, absent on one or more dates. Species abundance distributions of the entire community, and separately the core and occasional species, were compared with geometric, log‐series and log‐normal distributions. Core and occasional species were compared in terms of the shell or lorica oral diameter (LOD), analogous to gape size. Results We found 11 core and 49 occasional species. Diversity metrics were stable compared with shifts in abundances. Core species accounted for the majority of individuals in all samples. On each date, 9–22 occasional species, representing 10–15% of the population, were found. Species richness of the occasionals was positively related to population size. The identities of the occasional species found were unrelated to the time between sampling. The species abundance distribution of the occasional population was best fit by a log‐series distribution, while that of the core species was best fit by a log‐normal distribution. The species abundance distribution of the entire community was best fit by a log‐series distribution. Most of the occasional species had LODs distinct from that of a core species and occupied size classes left empty by the core population. However, the most abundant and frequent of the occasional species had a LOD similar to that of a core species. Main conclusions Among tintinnids, which are planktonic protists, occasional species have a species abundance distribution pattern distinct from that of core species. Occasional species appeared to be composed of two groups, one of relatively abundant species and similar to core species, and a second group of ephemeral species with morphologies distinct from core species. The existence of two categories of occasional or rare species may be common: (1) those similar to, and thus perhaps able to replace, dominant species in the absence of a change in the environment; and (2) those distinct from dominant species and requiring different conditions to prosper.  相似文献   

16.
Patterns in the relationships among the range, abundance, and distribution of species within a biome are of fundamental interest in ecology. A self-similarity condition, imposed at the community level and previously demonstrated to lead to the power-law form of the species-area relationship, is extended to the species level and shown to predict testable power-law relationships between range size and both species abundance and area of census cell across scales of spatial resolution. The predicted slopes of plots of log(range size) versus log(abundance) are shown to be in good agreement with data from British breeding bird and mammal censuses and with data on the distribution of fern species in old-growth forest. The predicted slopes of plots of log(range size) versus log (area of census cell) are consistent with the limited available data for British plant species. Self-similarity provides a testable theoretical framework for a unified understanding of patterns among the range, abundance, and distribution of species.  相似文献   

17.
秦岭及陕北黄土区辽东栎林群落物种多样性特征   总被引:17,自引:0,他引:17  
应用5种物种多样性测度指标及4种物种—多度分布模型对秦岭和黄土区辽东栎林种子植物物种多样性及木本植物种—多度分布进行了对比研究,结果表明:秦岭辽东栎林无论是群落物种多样性还是各层次的物种多样性均高于黄土区辽东栎林。秦岭辽东栎林木本植物种—多度分布符合对数正态分布而黄土区辽东栎林则符合对数级数分布,分布区气候差异是造成两类辽东栎林物种多样性差异的主要原因。物种—多度分布分析与物种多样性分析结果是一致的。  相似文献   

18.
R. G. Death 《Hydrobiologia》1996,317(2):97-107
Spatial and temporal patterns in the species abundance distribution of benthic invertebrate communities of 11 freshwater habitats (10 streams and a wind-swept lake shore) were examined with respect to habitat stability. Abundance patterns varied markedly between seasons at most sites. However, mean abundance distributions at 4 of the 5 unstable sites and the 2 most stable sites were dominated by one or two taxa with a large number of rare species, whereas sites of intermediate stability had more equitable distributions. Both the log series and log normal distributions were statistically indistinguishable, at the 5% level, from all the observed mean abundance patterns. In contrast, graphical comparisons of the observed and fitted distributions suggested the log series may be the better fit at most of the unstable sites and the two most stable sites, whereas the more equitable distribution at sites of intermediate stability suggested the log normal distribution was the better fit. If conditions at a site favoured one or two species, either through severe physical conditions, or through competitive superiority in the absence of disturbance then the log series distribution may result. However, if no species in the community was strongly advantaged over others, a log normal distribution should result. Given the discriminating power of the appropriate statistical test it may not, however, be possible to pick up these differences without graphical comparisons as well.  相似文献   

19.
森林群落物种多样性格局和动态一直是生态学的研究热点,人工林弃管后演替进程中物种多样性变化也很值得研究。杉木(Cunninghamia lanceolata)作为我国南方林区人工栽培最广、经济价值最高的用材树种之一,其人工林分布面积很大,通常群落结构简单、物种多样性低,然而群落中杉木数量如何影响植物物种多样性,迄今缺乏研究。在浙江省自然保护区内,选择不同疏伐强度和弃管时间的杉木人工林,建立了6个1 hm~2长期动态监测样地,在10 m×10 m、20 m×20 m、50 m×50 m和100 m×100 m尺度下,探究群落物种多样性(物种丰富度、Simpson指数、Shannon-Wiener指数和Pielou均匀度指数)的变化规律,分析杉木数量(多度和相对多度)对物种多样性的影响。结果显示:弃管前对杉木林的疏伐强度越高,演替恢复后的群落物种多样性越高。相同疏伐程度下,物种多样性随演替时间的延长有先升高后降低的趋势。取样尺度小于100 m×100 m时,杉木数量与物种多样性呈极显著负相关;100 m×100 m尺度下仅杉木相对多度与3种多样性指数呈显著负相关,杉木多度与各物种多样性均无显...  相似文献   

20.
李超凡  范春雨  张春雨  赵秀海 《生态学报》2021,41(23):9502-9510
以吉林蛟河阔叶红松林的木本植物为研究对象,将30hm2的样地面积划分为5m×5m,10m×10m,20m×20m,25m×25m的连续取样单元,在4个不同尺度下分别统计各物种在每个取样单元中的有无,得到每个物种在不同尺度下的取样单元数。利用随机分布模型和负二项分布模型分析物种的多度分布,对比预测多度与观测多度讨论两个模型的科学性与实用性。结果表明:对于阔叶红松林而言,负二项分布模型在所有研究尺度上的预测精度都要优于随机分布模型。随机分布和负二项分布的模型预测误差随着研究尺度的增大而增大,因此选取较小的取样单元可以切实提高物种多度的预测精度。利用随机分布和负二项分布模型对多度较小的物种进行预测的效果要优于多度较大的物种。负二项分布模型适合用来模拟阔叶红松林的物种多度分布格局,并且模型的拟合效果受取样单元大小影响。  相似文献   

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