吉中地区晚古生代腕足动物古生物地理与环境的协同演化*

吉中地区发育了普里道利期—洛霍考夫期Retziella、杜内期通气沟组以及空谷期—沃德期哲斯等腕足动物群。前两者属于"暖水"动物群、后者属于"凉水"动物群。同时参考珊瑚和等动物群分析,说明吉中地区从普里道利期至阿瑟尔期发育"暖水"动物群,从空谷期到沃德期发育"凉水"动物群。"凉、暖"转换是以寿山沟组的Monodiexodina动物群为代表,发生在萨克马尔期。"凉、暖"水动物群的发育及其转换是构造古地理与气候变化双重因素导致的结果。晚志留世—早泥盆世,西伯利亚板块、哈萨克斯坦板块、佳-蒙地块均位于中—低纬度带。吉中地区晚志留世—早泥盆世(乃至中泥盆世)腕足动物群属于"暖水"动物群,古生物地理区划属于中-澳生物地理区。石炭纪,东欧板块东北缘、哈萨克斯坦板块大部分地区、佳-蒙地块南缘属于特提斯洋北缘构造域,发育了特提斯洋北缘腕足动物群,形成了特提斯北缘生物地理区,吉中地区腕足动物群属于这一生物地理区。空谷期—沃德期凉水型哲斯腕足动物群的形成是由于佳-蒙地块西端与塔里木板块以及华北板块西端拼合,形成了西拉木伦洋构造域,以及此时期全球降温事件导致的结果。古生物地理、构造古地理以及古气候之间的协同演化关系表明吉中地区晚古生代地层应属于佳-蒙地块南缘的大陆边缘沉积。     

浙西早寒武世梅树村期棒状化石

该文记述了浙江省西部江山县新塘坞地区灯影组(梅树村期)中新发现的矿化骨骼化石——浙江棒(新属)Zhejiangorhabdion gen.nov.。该化石的形态与以往化石类群均不相同,为个体微小的棒状,表面具较复杂的纹饰,不同个体间的纹饰都有一定变化,推测是动物体内不同部位的骨棒所具有的特征,代表了一个新的化石类群。新属的发现丰富了梅树村期动物群的内容,对了解具骨骼动物群体在这一时期的演化具有一定的意义。     

西伯利亚地台早寒武世钙藻的发育特征

西伯利亚地台的新元古代到早寒武世间的钙藻化石特别丰富,为研究钙藻化石的发育历史提供了模式。在几次演化事件背景下记录了演化的两次转折,其中一个是藻类的普遍钙化,还有一个是Botomian晚期到Toyonian早期之间在西伯利亚地台缺失钙藻化石记录,而在其它地区包括西伯利亚地台的边缘(Altay—Sayan地区),钙藻的丰度却达到了最大。     

江西玉山王家坝早志留世早期（EarlyLlandoverian）新腕足动物群的发现…

系统描述江西省玉山县王家坝地区早志留世早期地层中新发现的腕足动物群６目、９超科、１７科、２１属、２８种,并将它们统称为Ｉｓｏｒｔｈｉｓ－Ｌｅｐｔａｅｎａ动物群。同时指出发现该腕足动物群的意义及其生存的地质时代。     

湖北京山早三叠世有孔虫动物群的发现及其意义

本文首次报道了湖北京山地区早三叠世有孔虫动物群,计６属１５种,其中包括４新种,在对该动物群分析基础上,作者建立了Ａｕｌｏｔｏｒｔｕｓｃｈｉａｌｉｎｇｃｈｉａｎｇｅｎｓｉｓ－Ｄｉｃｈｏｓｐｉｒａｓｉｎｅｎｓｉｓ组合带,通过对其古生态特征及生物相研究,揭示了该动物群的生活习性与生态环境的关系,简述了该有孔虫动物群的发现在地层划分对比及油气勘探中的意义。     

贵州东部下寒武统杷榔组上部的三叶虫

贵州凯里市西北郊瓮岭塘寒武系都匀阶下部(下寒武统)杷榔组顶部和镇远县江古镇杷榔组上部的杷榔动物群,是新近发现的重要动物群。动物群由始海百合与莱德利基虫类三叶虫及多门类的化石组成,表明黔东早寒武世都匀期早期斜坡相生物的多样性。就属种而言,三叶虫类最为丰富,计有4属5种,1亚种和1未定种,包括莱得利基虫类的Redlichia(Pteroredlichia)chinensis,Redlichia(Pteroredlichia)chinensislui,Redlichia(Pteroredlichia)murakamii,耸棒头虫类Arthricocephaluschauveaui,Changaspisplacenta,Changaspismicropyge及褶颊虫类Probowmania(Probowmania)sp.。褶颊虫类Probowmania(Probowmania)的出现,丰富了黔东地区杷榔组上部三叶虫组合,层位明显下延。文章还报道Redlichia(Pteroredlichia)chinensis分节末期到成虫早期个体发育特征。     

陕西洛南龙牙洞动物群的特点、时代及环境

从陕西洛南龙牙洞中采得哺乳动物化石３０多个属种,与之共存的有洛南直立人及其石制品。该动物群中同时具有古北区和东洋区的动物,为华北－华南动物地理区系间的一个过渡性动物群,时代为早更新世晚期,可与公王岭动物群对比。动物群的性质反映了当时洛南地区乃至秦岭东段为一温暖、湿润的森林草原环境,部分属种可能主要因为不适应急剧变化的气候而绝灭。     

辽河断陷东部晚寒武世至早奥陶世牙形石物地层

根据王参1井和界3井所产的牙形石动物群的分析,讨论了辽河断陷东部存在晚寒武世长山组;早奥陶世下马家沟组和冶里组的地层,与国内外有关的地区进行了对比,同时,以实例说明了仅仅根据岩性和电性划分出的晚寒武世凤山组、崮山组,中寒武世张夏组以及早奥陶世上马家沟组、亮甲山组层尚需进一步的系统的牙形石生物地层工作来核实或修正。     

树锦鸡儿的分布式样及其生态适应

树锦鸡儿为典型的中生植物,既是锦鸡儿属的模式种,又是该属植物的原始种。本文认为树锦鸡儿的分布式样为西西伯利亚东南部（阿尔泰—萨彦）—东亚北部（华北—东北—远东）间断分布种。在西西伯利亚东南部地区,本种为寒温型常绿针叶林西伯利亚落叶松和西伯利亚冷杉林下及林缘的伴生种,在东亚北部地区本种为中温型和暖温型夏绿阔叶林蒙古栎和辽东栎林下及林缘灌丛的伴生种。     

湘东南栖霞组底部石炭-二叠纪有孔虫混生动物群的发现

首次报道湖南省邵东保和堂柳东地区栖霞组底部与史塔夫（Staffella)Ting类群共生的丰富的小有孔虫动物群,包括19属、62种,其中新种2个,该动物群具有非常典型的石炭－二叠纪有孔虫群的混生特点,称Bradyina-Geinitzina组合,它标志着“隆林阶”在湖南地区的首次发现。     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

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     

Selection with two alleles and complete dominance

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.