山东聊城地区阿城镇煤田二叠纪孢粉组合

对山东聊城阿城镇煤田A19-6、A20-6、L104钻孔岩石样品进行了分析,发现从太原组中上部到上石盒子组地层中均有大量孢粉化石保存,经分析鉴定和统计,共有孢粉化石53个属168种及部分未定种.根据孢粉属种的纵向分布情况及含量的变化,在本区二叠系建立了4个孢粉组合,自上而下为:Ⅳ.Triquitrtites microgranifer-Macrotorispora media组合带;Ⅲ.Limitisporires rhombicorpus -Patellisporites meishanenisis组合带;Ⅱ.Gulisporites cochlearius-Sinulatis porites sinensis组合带;Ⅰ.Thymospora pseudothiessenii-Laevogatisporites vulgaris组合带.通过与邻区及华北部分地区对比,确定本区孢粉组合所在的地质时代应为:太原组中上部,早二叠世早期(组合Ⅰ);山西组,早二叠世中期(组合Ⅱ);下石盒子组,早二叠世晚期(组合Ⅲ);上石盒子组,晚二叠世早期(组合Ⅳ).     

波环孢属(Sinulatis porites)在华北地区的时空分布及其地层学意义

对鲁西晚古生代含煤岩系以及华北各地石炭、二叠系孢粉组合中已经发现的Sinulatisporites一属的时空分布进行详细研究,结果表明：其时空分布仅限于华夏植物区的北方亚区,在时间上始于早二叠世早期(太原组),灭绝于中二叠世中、晚期,可视为鲁西乃至华北地区早二叠世晚期、中二叠世早期中期华夏植物区北方亚区的典型分子。其母体植物可能为一种喜湿热的真蕨植物或种子蕨植物。该属产出层位稳定,延续时间较短,在月门沟统山西组、石盒子统下石盒子组含量丰富,又常产出于月门沟统山西组的主要含煤岩段及其上部石盒子统下石盒子组的砂、泥岩段,故可作为二叠系划分和对比煤层的重要依据。     

天津张贵庄晚二叠世孢粉植物群

天津张贵庄SR13号钻孔原归为石盒子组的地层近顶部发现了丰富的孢粉化石,这一组合兼具上石盒子组和孙家沟组孢粉组合的特征。一方面,它与上石盒子组（特别是其上部）组合有不少共同分子,在蕨类孢子和裸子植物花粉（包括具肋花粉）的含量比例上也可以与之对比,但缺乏一些标志分子。另一方面,在属种组成上,当前组合与已知的孙家沟组合也颇可比较,而且出现了一些中生代色彩的分子。这一组合的揭示与研究有助于提高人们对华北晚二叠世晚期孢粉植物群特征的认识。依据当前组合与已知相关孢粉组合的对比讨论,将其时代定为晚二叠世,并倾向于晚二叠世晚期（对应于孙家沟组）。     

新疆准噶尔盆地东部覆盖区锅底坑组的发现及其化石证据

本文对准噶尔盆地东部CS-1井1 082—1 126m井段10块样品中所含孢粉和大孢子化石进行了比较系统的分析研究,共获得孢粉化石68属114种,以及少量大孢子化石,并建立Limatulasporites fossulatus-Klausipollenites schaubergeri孢粉组合,组合以Limatulasporites fossulatus和Kraeuselisporites spinullous比较发育,并见有Klausipollenites schaubergeri,Lundbladispora和Welwitschipollenites clarus等为主要特征。根据孢粉组合特征和大孢子化石的分布规律,详细讨论了含化石井段地层的时代及层位,认为该段地层的时代为晚二叠世晚期至早三叠世早期,层位为锅底坑组。     

鲁西地区二叠系上、下石盒子组孢粉组合及其分界

为解决鲁西地区上、下石盒子组分界问题,在相关地层共采集处理孢粉样品100多块,经系统研究建立本区上、下石盒子组两个孢粉组合,自下而上为：1)Sinulatisporites sinensis-Patellisporites meishanensis组合;2)Anticapipollis reticor pus-Macrotorispora gigantea组合。根据所建立的孢粉组合特征,经与华北各地二叠系孢粉组合广泛对比,进一步阐述各孢粉组合的地质时代,并为本区二叠系上、下石盒子组的分界提出了较为可靠的意见。该界线与区内中期华夏植物群晚期和晚期华夏植物群早期植物群界线基本一致。     

南海北部珠江口盆地深水区LW5井晚渐新世——早中新世孢粉组合

本文对南海北部珠江口盆地深水区LW5井3 070—3 480m井段81个孢粉样品进行了分析,共鉴定86个孢粉属种类型;另有沟鞭藻和有孔虫内膜。根据孢粉和藻类化石组合面貌、丰度变化和特征分子的分布规律,将研究井段地层划分为2个孢粉组合:3 070—3 325m井段为Polypodiaceaesporites-Dinocysts组合,层位相当于珠江组,时代为早中新世。本组合含丰富的沟鞭藻和微有孔虫,孢粉以Graminidites,Zonocostatites和Chenopodipollis等为主,沉积环境为滨浅海,气温较高,指示了湿润的热带、亚热带古气候;3 330—3 470m井段为AlnipollenitesPinuspollenites组合,与珠海组层位相当,地层时代为晚渐新世。本组合沟鞭藻和微有孔虫少量出现,孢粉含丰富的Pinuspollenites和Abietineaepollenites,出现较多的Cedripites等,反映海陆交互的古环境,显示了气温低的亚热带古气候。     

塔里木盆地二叠系孢粉组合及生物地层学*

首次系统地研究了塔里木盆地二叠系孢子花粉，讨论了盆地各地层分区孢粉组合特征，建立了从早二叠世至早三叠世早期的6个孢粉组合带，阐述了各组合带孢粉学特征。依据对盆地二叠纪孢粉植物群组成分子的分析及其与国内外相关孢粉组合的比较研究，将盆地孢粉植物群分为3个发展阶段，即：早二叠世早、中期的欧美型植物群，早二叠世晚期至晚二叠世早期的安加拉欧美混生型植物群和晚二叠世中、晚期的安加拉型植物群。文中还从孢粉地层学角度论述了沙井子组、杜瓦组和普司格组的地质时代以及二叠/三叠系界线等问题。描述孢粉25属33种（含2新种）。     

江苏句容上二叠统龙潭组孢粉组合及孢粉热变指数和有机质类型

通过对苏南句容A10井的孢粉研究,首次发现了上二叠统龙潭组孢粉化石。根据孢粉组合特征。与国内同时期的孢粉组合进行了比较和讨论,并用孢粉热变指数和有机质类型,对龙潭组进行了油气评价。为苏南地区晚二叠世的地层对比,提供了新的古生物依据。     

山东滕县煤田石炭-二叠纪孢粉组合

山东滕县上石炭统—二叠系含煤地层中发现大量保存良好的孢粉化石属种及部分未定属种。根据孢粉化石主要属种的纵向分布规律及含量的变化,建立了本区五个孢粉组合带,自上而下为:V.Triquitrites-Macrotorisporacathayensis;IV.Patellisporitesmeishanensis-Torisporasecuris;III.Gulisporitescerevus-Sinulatisporitesshanxiensis;II.Thymosporapseudothiessenii-Laevigatosporitesvulgaris;I.Crassisporakosankei-Densosporitesanulatus。它们自上而下分别代表了本区晚古生代二叠系石盒子统上石盒子组、下石盒子组和月门沟统山西组、太原组上段以及上石炭统太原组下段。本文简述了各孢粉组合的特征,并与邻区及华北部分地区进行了对比;另外,还论证了滕县煤田晋祠组的存在。     

珠江口盆地揭阳凹陷早渐新世-中新世古生物地层及沉积环境

位于珠江口盆地揭阳凹陷的S1井是盆地东南部唯一钻井,其地层和沉积环境分析意义重大。本研究通过对S1井孢粉、有孔虫和钙质超微化石地层对比分析,确定了所钻地层时代。井段(3 326.5～2 950 m)共鉴定孢粉40属62种,孢粉组合无明显变化,以桤木粉-双束松粉为主,组合与盆地内渐新统珠海组相同。整个分析段3 326.5～2 059.5 m共鉴定浮游有孔虫11属41种,依据标准种首末现事件共划分出P19-N6 5个带或联合化石带。钙质超微化石共鉴定8属24种,划分NP23-NN4共5个钙质超微化石带。综合判定:地层时代为早渐新世-早中新世(～31-18 Ma),渐新统与中新统的界限在2 876.5 m附近。利用浮游有孔虫的丰度和底栖有孔虫的组合来判别该地层的沉积环境,认为揭阳凹陷S1井在早渐新世-早中新世均为陆坡深水环境,水深>1 000 m。     

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.