带不完全椭球约束生长曲线模型线性估计的泛容许性

讨论带不完全椭球约束生长曲线模型中回归系数线性估计的泛容许性,给出了回归系数的线性估计在线性估计类中是泛容许估计的充要条件.     

小麦选系“7182—0—11—1”与黑麦可杂交性的遗传分析

小麦选系“７１８２－０－１１－１”与黑麦的可杂交性明显高于传统的高亲和性品系“中国春”。遗传分析表明,“７１８２－０－１１－１”与“中国春”的可杂交性基因一样表现为完全隐性,“７１８２－０－１１－１”除具有“中国春”的３对可杂交性基因,好５Ｂ上的ｋｒ１、５Ａ上的ｋｒ２和５Ｄ上的ｋｒ３外,还具有一个新的可杂交性基因ｋｒ５,位于２Ｂ染色体上,ｋｒ５表现为强效,其效应接近ｋｒ１,小麦可杂交性隐性纯合等位     

小麦新材料“J—11”与黑麦可杂交性的遗传研究

新材料“J－11”比众所周知的高亲和性品系“中国春”具有明显更高的与黑麦的可杂交性,遗传分析表明,“J－11”与“中国春”的可杂交性基因一样表现为完全隐性,但控制“J－11”和“中国春”与黑麦可杂交性的基因型确实不相同,“J－11”除具有“中国春”的3对可杂交性基因,即5B上的kr1,5A上的kr2和5D上的kr3,外,还具有1个新的可杂交性基因kr4,位于1A染色体上,新基因kr4表现为强效,其效应比kr1的弱,但在kr2和kr3的强。小麦可杂交性基因间存在互作,表现为纯合隐性等位基因对其它显性等位基因的抑制作用,而纯合隐性等位基因的效应可加性。     

氨基甲酸酯类农药（叶蝉散）在地面水中最高容许浓度的研究

通过急性、蓄积、慢性毒性、致畸性和致突变性的毒理学试验,得出异丙威的最大无作用剂量为1．0mgkg.bw。据此计算出每日容许摄入量为0．01mg／kg.d,以成人每人每天饮水3L、体重60kg以及从水体进入人体的异丙威为总摄入量的9％计算,则异丙威在水中的浓度为0．018mg/L,这一浓度可满足其对地面水感官性状和自净过程两方面的要求,因此建议地面水中异丙威的最高容许浓度不应超过0．018mg/L。     

生物多样性价值的经济学处理：一些理论障碍及其克服

本文首先对国际生态经济学界围绕“世界生态系统功能价值计量”的方法学论争进行短简的评价,接着阐述了生物多样性价值的新的概念框架,并据此就生物多样性价值计量中尚未得到关注的问题（生物多样性价值的可计算性,价值计量方法的恰当性,价值分量的可加性和可解析性,价值误差测算）提出解决思路,本文最后讨论了两个保护经济学问题方法学构架,其一是生物多样性破坏的经济损失计算,其二是生物多样性保护工程的成本－效益体质与成本－效果分析。     

农作物种子检验中发芽试验的容许误差的统计模型与计算

当代计算手段远远优于计算种子检验规程发芽试验现行标准中容许误差数值的20 世纪60年代,鉴于此,本文在提出发芽试验统计检验模型的基础上,利用MATLAB编程重新计算了容许误差值．过去计算的三种容许误差有较大的正偏差,另一种有很小的负偏差．建议对现行的种子检验规程有关计数型的容许误差数值进行修订．     

对人眼晶状体α－晶体蛋白聚集体的准弹性激光散射研究

以准弹性激光散射技术,研究了人眼晶状体内α－晶体蛋白聚集体的扩散系数和流体力学半径,以及其弥散性随温度和浓度的变化。所研究的α－晶体蛋白用分离的方法分别取自成人和胚胎眼晶状体。研究结果表明,人眼α－晶体蛋白在一定浓度和温度下可形成聚集体,且其聚集体半径随α－晶体蛋白的浓度近乎线性地增大,随温度的增加而变小。对α－晶体蛋白溶液（５０ｍｍｏｌ／Ｌ磷酸脂缓冲液）的弥散度分析表明,溶液中有两种不同粒径的散射体,除开α－晶体蛋白聚集体外,还有一种粒径约为１８．５ｎｍ的估计是α－晶体蛋白单体分子。由于α－晶体蛋白分子的变性聚集在人眼白内障的形成起着重要作用,故本研究的结果对于人眼白内障随年龄及温度变化的发展过程及其机理的认识具有指导意义。     

一种新型的可诱导性基因表达系统：Tet—off／Tet—on基因表达系统

Ｔｅｔ－ｏｆｆ／Ｔｅｔ－ｏｎ基因表达系统是新近发展起来的高效,无毒,具有严密开／关功能的基因表达系统。自推出以来,在很多方面得到了广泛的应用,尤其是在基因的表达调控及基因治疗上。本文拟就Ｔｅｔ－ｏｆｆ／Ｔｅｔ－ｏｎ基因表达系统的基本工作原理以及主要应用作一综述。     

黄土高原地区土壤可蚀性及其应用研究

通过回顾已有的成果,分析评价了我国土壤可蚀性研究的进展及存在的问题,提出我国土壤可蚀性研究中的标准小区定义,运用野外观测资料,研究计算了黄土高原地区土壤可蚀性指标标值,结果表明,陕北和晋西北一带黄土可蚀性K值变化于0．3－0．7之间,并且有以陕西子洲,绥德一带为最大,以此为中心,向南,向北和向东都减少的变化趋势。     

线性广义系统的无源控制

研究线性广义系统在有界能量外部输入作用下的无源控制问题,给出广义系统容许且具有严格无源性的充分条件,并且在一定条件下设计一个状态反馈控制器使得闭环系统容许,同时具有严格无源性．     

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.