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《小哥白尼(野生动物画报)》2014,(8)
<正>"这天下是雄性同胞的天下,我不敢说其他动物,但在长颈象鼻虫的世界里是这样的。"长颈象鼻虫维克多先生总是表现出一副高傲的姿态,在无数枝端和叶尖说这样的话。这也难怪,谁让人家长得那么"帅"气逼人。光鲜亮丽是雄虫长颈象鼻虫来自美丽的马达加斯加,酷爱红黑色经典搭配,尽管其背上鲜红的鞘翅看起来很抢眼,但那毕竟是雌雄虫都有的特征,没啥好炫耀的。因此,其实最让雄性长颈象鼻虫引以为傲的还是它们的脖子。雄长颈象鼻虫有点儿拷贝长颈鹿的造型,脖子比自己身体长出好大一截。每天挺着这么酷的脖子走在树枝尖,回头率可想而知。 相似文献
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长颈树蜂属(Xiphydria)是长颈树蜂科(Xiphydriidae)最大的一个属,全世界已知26种,现增加采自我国云南的一新种。多斑长颈树蜂Xiphydria Plurimaculata,新种。 雌虫:触角第1~4节、第5节基部2/3和最末一节黑色,其余各节黄白色。头部黑色,上颚基部、唇基、触角窝内上方两斑、颊与它相联向后及向眼内缘伸长部分,以及由眼内缘上方向头顶延伸两纵纹黄白色。胸部黑色,前胸背板侧角,前胸侧板大部分、颈 相似文献
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记述了贵州兴义法郎组竹杆坡段(中三叠世拉丁期)长颈龙属未定种(Tanystropheus sp.)一幼年个体的不完整骨架。这是该属在欧洲和中东以外的首次发现。新材料仅保存部分颈椎、躯干和前肢。根据特殊的颈椎形态将该标本归入长颈龙属,而区别于另一种长颈的海生原龙类——东方恐头龙(Dinocephalosaurus orientalis)。新标本的腕骨形态简单,骨化程度弱,表明长颈龙是终生水生的动物。“长颈、长颈肋”见于多种不同海生爬行动物(如原龙类、初龙类),它们很可能都以“吞吸”的方式捕食。长颈龙化石在我国的发现进一步验证了中国南方三叠纪海生爬行动物群与欧洲西特提斯动物群(western Tethyan fauna)之间的密切关系。 相似文献
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贵州中三叠世长颈龙属(原龙目:长颈龙科)一幼年个体 总被引:1,自引:1,他引:1
记述了贵州兴义法郎组竹杆坡段(中三叠世拉丁期)长颈龙属未定种(Tanystropheus sp.)一幼年个体的不完整骨架。这是该属在欧洲和中东以外的首次发现。新材料仅保存部分颈椎、躯干和前肢。根据特殊的颈椎形态将该标本归入长颈龙属,而区别于另一种长颈的海生原龙类———东方恐头龙(Dinocephalosaurus orientalis)。新标本的腕骨形态简单,骨化程度弱,表明长颈龙是终生水生的动物。“长颈、长颈肋”见于多种不同海生爬行动物(如原龙类、初龙类),它们很可能都以“吞吸”的方式捕食。长颈龙化石在我国的发现进一步验证了中国南方三叠纪海生爬行动物群与欧洲西特提斯动物群(western Tethyan fauna)之间的密切关系。 相似文献
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亏祖山秋季不同海拔土壤纤毛虫优势种生态位及其与环境因子的关系 总被引:1,自引:0,他引:1
为深入了解拉萨河流域亏祖山不同海拔梯度秋季土壤纤毛虫优势种生态位及其与环境因子的关系,于2015年10月在亏祖山共设置11个样点,用土壤采样器采用梅花五点式采集土样,同时记录相应的理化因子,土样在实验室自然风干后,采用"非淹没培养法"和"活体观察法"进行培养和形态学鉴定。亏祖山11个样点中,共鉴定到土壤纤毛虫132种,隶属3纲14目48科66属,其中14个优势种(Y>0.02)。土壤纤毛虫优势种生态位宽度最大的是明显长颈虫(Dileptus conspicuus),生态位宽度最小的是卵圆前管虫(Prorodon ovum)和似肾形虫(Colpoda simulans)。土壤纤毛虫优势种生态位重叠值位于0.02-0.99之间,生态位重叠值最低的为似肾形虫(Colpoda simulans)和卵圆前管虫(Prorodon ovum),而生态位重叠值最高的为念珠角毛虫(Keronopsis monilata)和膨胀肾形虫(Colpoda inflata)。亏祖山14个优势种生态响应速率之和为负值,表明土壤纤毛虫优势种处于衰退阶段。土壤纤毛虫优势种与环境因子的典范对应分析(CCA)结果显示,轴1和轴2累计解释物种变异的37.8%,表明轴1和轴2能较好地反映优势种与环境因子的关系;总氮是显著解释变量,对优势种变异的解释率为17.6%。综上分析得出,明显长颈虫(Dileptus conspicuus)、点滴半眉虫(Hemiophrys pectinata)和前口瞬目虫(Glaucoma frontata)对土壤环境适应能力较强,具有广泛的生态适应幅度;土壤纤毛虫优势种生态位重叠值低,种间竞争比较弱;土壤纤毛虫优势种之间以及优势种和环境之间尚未达到相对的动态平衡,优势种正处衰退阶段;总氮是影响拉萨河流域土壤纤毛虫优势种分布和生态位的主要环境因子。 相似文献
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屏顶螳属Kishinouyeum由Ouchi氏建立于1938年,隶属于长颈螳科Vatidae,长颈螳亚科Vatinac.本记述采自云南西双版纳的屏顶螳属一个新种,短屏顶螳Klshinouyeum breve,sp.nov新种模式标本保存于中国科学院上海昆虫研究所. 相似文献
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在地史上的中生代,长颈恐龙的肺部所产生的巨大浮力,足以使长颈恐龙浮于水面而游动,但是为什么它的身体竟有5米之多的部位始终沉没于水中?这个离奇的不解之谜,引起了各国古生物学者的巨大兴趣。学者D.G.德庇在挖掘长颈恐龙化石时,往往在其胃部发现许多被食而未消化的小动物化石及许多石块,终于揭开了这个不解之谜。原来,长颈恐龙与鳄鱼一样,会把许多石块食进胃中,以增加体重来使身体沉没于水中,将鼻与眼伸出水面,来捕获猎物。此外,学者J.A.比松还研究了长颈恐龙的四只脚,根据其脚是前端呈尖状的翼型,断定长颈恐龙不是依靠脚蹼来游动的,它如同海豹、企鹅一样,借助于上 相似文献
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采用林间调查和室内饲养等方法,发现了油茶林鳞翅目害虫的3种天敌,即印度长颈步甲Ophionea indica、日本长颈步甲Mimocolliuris insulana和茶梢尖蛾长体茧蜂Macrocentrus parametriates ivorus,前2种天敌主要捕食鳞翅目卷叶类害虫、假眼小绿叶蝉Empoasca vitis等,且为首次在油茶林中发现;茶梢尖蛾长体茧蜂寄生茶梢尖蛾Parametriotes theae幼虫,为首次在广东省记录。记述了3种天敌的形态特征、寄主、国内分布及生物学特性等。 相似文献
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水稻上的一类小型步行虫 总被引:1,自引:0,他引:1
我国南方水稻上常见一类小型步行虫,它们的头部具有狭细的“颈部”,前胸背板简形,中部两侧膨出,鞘翅宽阔,一些种类不仅形状相似,其中有一些色泽及斑纹亦十分近同。它们属于步行虫科(Carabidae)长颈步甲族(Odacanthini)。这一类步行虫在白天十分活跃,成虫、幼虫捕食稻飞虱、纵卷叶螟等害虫,是水稻害虫的重要天敌,为便于识别,本文列出了较常见的8种长颈类步行虫的检索表。 相似文献
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Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献