论四射珊瑚征珊瑚属 Charactophyllum Simpson,1900

对Ｃｈａｒａｃｔｏｐｈｙｌｕｍ作了全面的回顾整理,记述了本属的骨骼构造,在此基础上讨论了其定义范围和时空分布及有关的分类问题。Ｃｈａｒａｃｔｏｐｈｙｌｕｍ的隔壁为板状隔壁而非包珊瑚型隔壁,由波状弯曲的单列单晶榍组成,单晶榍整体呈半扇形排列而非扇形排列,隔壁光滑或发育微弱的榍凸（ｃａｒｉｎａｅ）而无典型的横耙状榍凸（ｙａｒｄａｒｍｃａｒｉｎａｅ）,鳞板半扇形排列而不是扇形排列。本属分布仅限于北美和华北的晚泥盆世早期。Ｃｈａｒａｃｔｏｐｈｙｌｕｍ隔壁中单晶榍由放射状排列的不规则短轴晶柱和晶针组成,横列构造鳞板和横板均由晶板型层状骨骼组成。本属骨骼微细构造的重要特征具有奥陶志留纪与石炭二叠纪四射珊瑚之间的过渡性质。表明四射珊瑚骨骼微细构造演化趋向稳定,是追索演化的重要线索,在较高级别的分类中具有重要意义     

论四射珊瑚征瑚属Charactophyllum Simpson,1990

对Ｃｈａｒａｃｔｏｐｈｙｌｌｕｍ作了全面的回顾整理,记述了本属的骨骼构造,在此基础上讨论了其定义范围和时空分布及有关的分类问题。Ｃｈａｒａｃｔｏｐｈｙｌｌｕｍ的隔壁为板状隔壁而非包珊瑚型隔壁,由波状弯曲的单列单晶榍组成,单晶榍整体呈半扇形排列,隔壁光滑或发育微弱的榍凸（ｃａｒｉｎａｅ）而无典型的横耙状榍凸（ｙａｒｄａｒｍ ｃａｒｉｎａｅ）,鳞板半扇形排列而不是扉形排列。本属分布仅限于北美和华北的晚     

论四射珊瑚包珊瑚科（AmplexidaeChapman,1893）的分类

讨论了包珊来龙去脉 科（ＡｍｐｌｅｘｉｄａｅＣｈａｐｍａｎ１８９３）的分类。把包珊瑚型隔型限于仅在外端连续,向轴部变薄呈短而低的脊状,纵向呈下连续的着生于横板之上。包珊瑚型隔壁的微细构造以层状骨骼为主,其轴部有时可出现非晶榍型纤状之骨骼,包括晶粒和短轴晶柱。     

聚类分析法对镣珊瑚类的修订

镣珊瑚类是奥陶纪-志留纪地层中常见的以链状珊瑚复体为特征的一类床板珊瑚,地理分布广泛,研究历史较长。但不同学者对其骨骼构造特征的分类学意义认识不一,使得类群中许多属的定义和范围长期存有争议。本文结合我国的已发表材料,对镣珊瑚的分类进行简要讨论,依据隔壁刺的有无将镣珊瑚分为Catenipora和Quepora两属,认为Procatenipora和Eocatenipora分别是前者和后者的同义名。运用聚类分析的方法对我国镣珊瑚类的种进行修订。     

聚类分析法对镣珊瑚类的修订北大核心

镣珊瑚类是奥陶纪-志留纪地层中常见的以链状珊瑚复体为特征的一类床板珊瑚,地理分布广泛,研究历史较长。但不同学者对其骨骼构造特征的分类学意义认识不一,使得类群中许多属的定义和范围长期存有争议。本文结合我国的已发表材料,对镣珊瑚的分类进行简要讨论,依据隔壁刺的有无将镣珊瑚分为Catenipora和Quepora两属,认为Procatenipora和Eocatenipora分别是前者和后者的同义名。运用聚类分析的方法对我国镣珊瑚类的种进行修订。     

论实轴型中柱皱纹珊瑚的分类

具实轴型中柱的皱纹珊瑚的分类位置至今尚未取得统一。这类珊瑚的轴部由纤状组织构成,它不同于复中柱或皱形复中柱,它的形成与主隔壁,对隔壁或一级隔壁内端没有关系,是皱纹珊瑚中一类独立发育的轴部构造。具实轴型中柱的珊瑚可以独立建立新目,称Ｃｙａｔｈａｘｏｎｉｉｄａ ｏｒｄ．ｎｏｖ．。按照组成实轴的纤状组织类型和实轴形态,可以划分为３科,即Ｃｙａｔｈａｘ－ｏｎｉｉｄａｅ ｅｄｗａｒｄｓ ｅｔ Ｈａｉｍｅ,１     

论泡沫珊瑚目(Cystiphyllida)的细构造在分类及地层上的意义

泡沫珊瑚类是世界志留系和泥盆系常见的一类珊瑚化石,据不完全统计,目前被置于该目的属已有50多个,但是其中有不少属,仅根据泡沫板和隔壁刺的形态是难以区别的。例如:Cystiphyllum,Holmophyllum和Cystiphylloides3属之间,Cysticonophyllum,Hedstromophyllum和Wedekindophyllum3属之间,Protocystiphyllum,Gyalophyllum和Zonophyllum3属和Pseudomicroplasma与Microplasma2属之间,从它们的特征描述来看,并无明显区别。因此,长期     

论四射珊瑚微细骨骼构造的基本形式

一历史的回顾早在十九世纪中叶,珊瑚化石研究的开创者M.Edwards和Haime在其巨著中就明确提出珊瑚骨骼的组成单元是scleroderimites(与羽簇fibre fascicles同义),这些羽簇连续发育,成线状排列,则为pourtrales(与羽榍trabeculae同义)。关于骨骼分泌的方式,十九世纪末von Heider和von Koch几乎同时发现珊瑚软体底     

泡沫珊瑚目的新属种

对于泡沫珊瑚类化石,许多研究者注重于骨骼形态分类,因而目前一些属种包括范围较广,地质历程较长。虽然部分作者曾描述报道过隔壁细构造的某些特征,但对这些特征在分类中的意义并未引起足够的重视。1979年,笔者在中国古生物学会十二届学术年会上,提交     

新疆南天山中泥盆世泡沫轴珊瑚属(Aphraxonia)一新种

描述泡沫轴珊瑚属一新种———Aphraxoniawuqiaensissp .nov .,标本产于沿新疆南天山地区乌恰县托帕 吐乐尕特山口公路边的中泥盆统托格买提组。泡沫珊瑚属过去仅在土耳其Anatolia地区和我国湖南株州地区发现 ,目前在新疆中泥盆统的发现 ,不仅丰富了该属的化石种资料 ,同时也表明在中晚泥盆世南天山地区可能与土耳其Anatolia地区和华南地区存在密切的生物地理区联系。通过与该属已知 2个种特征和产出时代的对比 ,看出从中泥盆世Givetian期到晚泥盆世 ,可能存在从A .zhuzhouensis→A .wuqiaensissp .nov→A .taurensis的演化谱系和由华南→新疆南天山→土耳其的迁移路线。其演化趋势体现为 :1 )一级隔壁数目逐渐减少 ;2 )隔壁由中部加厚→边缘加厚 ;3)主、对隔壁分离 ,对隔壁伸过中心形成轴端微膨胀板状中轴→轴端膨胀明显的板状中轴→主、对隔壁在中心交汇形成轴端膨胀中轴 ;4 )一级隔壁不达中轴→与中轴相交。     

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.