河北下花园洪水庄组含炭质化石岩样的生物标志物

河北下花园古城梁东坡洪水庄组下部和上部藻层泥质白云岩中,存在大量直径8-25mm,的炭质薄膜化石7属8种.用生物标志物(化学化石)的研究结果,讨论这些化石的生物学性质和可能的亲缘.确认这样一些丰度极大的化石主要来源于后生藻类.     

中国遗迹化石研究80年

中国遗迹化石研究经历了零星(1929-1978)、系统(1978-2004)和创新(2004～)研究3阶段.在前寒武纪一寒武纪之交遗迹化石研究;海相遗迹化石及其古环境和古生态意义研究;陆相遗迹化石及其与能源形成环境关系研究;前寒武纪遗迹化石与后生动物的起源与演化研究;拓扑遗迹分析;遗迹化石在浊流、风暴事件和层序地层研究中的应用;复杂遗迹化石的地球生物学研究和遗迹化石模拟与可视化研究8个方面取得了显著的进展和成就.研究队伍偏少且不稳定;原创、系统、有深度、有影响的研究成果不多;缺少有力度的学科交叉和国际合作是存在的主要问题.加强遗迹学人才和团队培育,稳定支持几个有特色的遗迹学研究方向;基于遗迹学资料的系统积累,拓展和深化遗迹化石的地球生物学研究;加强遗迹化石在海、陆相油气资源评价和储层研究中的应用;创新遗迹化石的研究方法手段,重视和加强现代生物遗迹研究是值得今后进一步关注的问题.     

湖北元古代微体化石新材料

黄麦岭磷矿的8个中元古代黄麦岭组变质岩地层剖面中发现了两类微体化石。一类是丁丁虫中的Funnelasinensisgen.etsp.nov.,另一类是球形分类位置未定的Sinosphaera hubeiensisgen.etsp.nov.。两者均为多细胞化石,它们都含磷。在该磷矿中,凡是含微体化石越多的层位,磷矿的品位也就越高。     

贵州独山早石炭世上司组海参化石

从贵州独山早石炭世上司组海参化石的发现,进一步讨论海参集合体的特点及其意义,海参化石组合特征,并与国内外石炭系海参进行对比,同时描述了上司组海参化石8属12种,包括5新种.     

第二届"全国花粉资源开发与利用"研讨会在西安举行

从贵州独山早石炭世上司组海参化石的发现,进一步讨论海参集合体的特点及其意义,海参化石组合特征,并与国内外石炭系海参进行对比,同时描述了上司组海参化石8属12种,包括5新种.     

江西清江盆地早第三纪新余组腹足类化石

一、前言江西清江盆地早第三纪地层发育良好,产有丰富的腹足类化石,已报道的有清江组和临江组的非海相腹足类化石(余汶,1977,1983).本文记述的是清江盆地西部边缘新余县马洪乡新余组中的陆生腹足类化石,共计6属、8种,隶属4科,其中包括1新属和5新种.同时,对这一腹足类化石组合的性质及其时代特征,新余组的沉积环境及时代归属等问题进行了探讨.本文是在余汶老师悉心指导下完成的.承     

蜉蝣目化石的研究进展

回顾了世界蜉蝣目化石研究简史,列出已发表的化石种类名录、分布及年代,共40科、124属、218种,其中包括中国的8属13种;描述了不同地质时期主要蜉蝣化石的分类单元和分布地区.简要介绍了蜉蝣分类系统及系统发育、稚虫食性、与其它昆虫的关系和古生态等方面的研究成果.在本文的第2部分,初步分析了目前该类群所存在的一些问题,并对今后的研究工作进行了展望.     

中国早寒武世早期小壳化石的生物地理分区

中国是研究早寒武世早期小壳化石较早的国家之一,特别是最近十年来,随着震旦系-寒武系界线地层研究工作的深入开展,在全国各地先后发现了许多富含早寒武世早期小壳化石的地点,大大丰富了小壳化石的资料,各地早寒武世早期小壳化石的面貌渐趋清楚,在这个基础上探讨一下早寒武世早期小壳化石的生物地理分区很有必要。根据生物相、岩相特征及古地理位置三方面的因素可以将中国早寒武世早期(梅树村期—沧浪铺期)小壳化石的生物地理区划分为8个大区:Ⅰ.扬子区;Ⅱ.过渡区;Ⅲ.江南区;Ⅳ.东南区;Ⅴ.西北区;Ⅵ.华北-东     

旗腹蜂总科化石研究进展

旗腹蜂总科Evanioidea是膜翅目Hymenoptera在侏罗纪大辐射时出现的一个重要类群.自1910年Brues命名了早白垩世产于美国的旗腹蜂总科的化石昆虫Pristaulacus rohweri和Pristaulacus bradleyi以来,世界古昆虫学家发表了30余篇关于旗腹蜂总科昆虫化石的文章.共记载4科、8亚科、35属、110种,分布于18个国家.本文统计了世界已记载的旗腹蜂总科的化石名录、地理分布及地质年代,初步总结世界旗腹蜂总科昆虫化石的组成特征,提出旗腹蜂总科化石研究中存在的问题,及对未来研究的展望.     

我国泥盆纪鱼类的分布、组合和性质

文中记述了我国泥盆纪鱼类化石分布情况,并根据已描述的化石建立8个组合。     

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.