Genetic and phylogenetic analyses of human T-cell lymphotropic virus type I variants from Melanesians with an without spastic myelopathy

Molecular variants of human T-cell lymphotropic virus type I (HTLV-I) have been isolated recently from lifelong residents of remote Melanesian populations, including a Solomon Islander with tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) or HTLV-I myeloneuropathy. To clarify the genetic heterogeneity and molecular epidemiology of disease-associated strains of HTLV-I, we enzymatically amplified, then directly sequenced representative regions of thegag, pol, env, andpX genes of HTLV-I strains from Melanesians with and without TSP/HAM, and aligned and compared these sequences with those of HTLV-I strains from patients with TSP/HAM or adult T-cell leukemia/lymphoma and from asymptomatic carriers from widely separated and culturally disparate populations. Overall, the HTLV-I variant from the Solomon Islander with TSP/HAM, like HTLV-I strains from asymptomatically infected Melanesians, diverged by approx 7% from cosmopolitan HTLV-I strain. No disease-specific viral sequences were found. Gene phylogenies, as determined by the unweighted pair-goup method of assortment and by the maximum parsimony method, indicated that the Melanesian and cosmopolitan strains of HTLV-I have evolved along separate geographically dependent lineages, one comprised of HTLV-I strains from Papua New Guinea and the Solomon Islands, and the other composed of virus strains from Japan, India, the Caribbean, Polynesia, the Americas, and Africa. The total absence of nonhuman primates in Papua New Guinea and the Solomon Islands precludes any possibility that the Melanesian HTLV-I strains have evolved recently from the simian homolog of HTLV-I.     

酶电泳资料和系统与进化植物学研究综述

酶电泳资料和系统与进化植物学研究综述葛颂（中国科学院植物研究所系统与进化植物学开放研究实验室北京１０００９３）关键词同工酶,电泳,植物系统学,进化ＥＬＥＣＴＲＯＰＨＯＲＥＴＩＣＤＡＴＡＡＮＤＳＴＵＤＩＥＳＯＦＰＬＡＮＴＳＹＳＴＥＭＡＴＩＣＳＡＮＤＥＶ...     

鲑鱼生长激素基因分泌型表达质粒的构建

生长激素(GH)是动物垂体前叶分泌的一种多肽类激素.应用分子重组及PCR等技术,构建了一种鲑鱼生长激素基因分泌型表达质粒pOsGH153,使编码鲑鱼生长激素成熟肽的序列克隆在大肠杆菌分泌型表达载体PIN-Ⅲ-ompA内,直接位于编码大肠杆菌外膜蛋白A信号肽序列的下游,在Lpp-Lac杂合启动子控制下,经IPTG诱导,分子量约23 000的鲑鱼生长激素在大肠杆菌中获得高效表达,该产物具有天然鲑鱼生长激素的免疫活性,直接分泌到细胞周质,而信号肽被自动剪除.     

磁水对蕃茄酯酶同工酶的影响

蕃茄（ＬｙｃｏｐｅｒｓｉｃｏｍｅｓｃｕｌｅｎｔｕｍＭｉｌｌ）在各生长发育期酯酶同工酶谱带无明显变化,但经磁水处理后各生长发育阶段功能叶中酯酶同工酶酶谱及磷素含量与对照组相比存在显著差异,且具有酶谱负极端带数增加,正极端带数减少的趋势。总磷含量测定结果表明处理组均比对照组显著提高。这些变化在磁水处理著前后代中不存在,故认为磁水只是致使非编码顺序局部复制引起ＤＮＡ分子高级结构改变或是通过活化调节基因来调控酯酶同工酶,活化磷代谢,达到促进生长和增产的效果,而并非导致可遗传变异的结果。     

陕西关中小麦品种更替中性状演变及其发展方向

以关中地区四十年代到九十年代推广种植的主要代表品种及品系为材料,对其分蘖动态、生育期、株高因素、穗部性状、产量、生物学产量、经济系数及冬春性等２０个性状进行了研究,其结果表明关中地区四十代到九十年代小麦品种性状演变的趋势是：冬、春季分蘖变化不大,冬季分蘖趋向略增;春季分蘖趋向略减;成穗数趋向降低,拨节,抽穗和开花期有趋早倾向,而成熟期和总生育天数无明显变化,株高降低极明显（１３７．７－８５．２ｃｍ     

Interpretation of gas residence time distributions in large airlift tower loop reactors

Gas-residence time distribution (RTD) response curves measured in a 23 m high pilot plant airlift tower loop reactor, which consisted of a riser, a special downcomer construction and at the top of the riser a large head. The measurements were evaluated by means of a deterministic dispersion model, which yielded the following particular parameters for the riser, downcomer and the head: Gas-Bo numbers, gas-mean residence times, gas holdups, liquid velocities, gas and liquid circulation times as well as a fraction of the large and small bubbles in a model medium (water) and during cultivation of baker's yeast.List of Symbols A cross section - Bo Bodenstein number - Bo _d (= l _d w _G,d /D _d ) - Bo _h (= l _h w _G,h /D _h ) - Bo _r (= l _r w _G,r /D _r ) - D longitudinal dispersion coefficient - E gas holdup - E(t) RTD-density function - L, l length parameter - q fraction of the gas throughput which is not recirculated (approximately equal to fraction of the large bubbles) - r fraction of the throughput which is recirculated (approximately equal to the fraction of the small bubbles) - t _c circulation time - t _cL liquid circulation time - t _c,L ^* liquid circulation time calculated from the measured w _Ld in the downcomer - V ^h hydrodynamical calculated gas-liquid volume - V _d ^h (=V _d+0.75/2 V _k ) - V _k ^h =(0.25V _k ) - V _r ^h = (V _r+0.75/2 V _k ) - V _L liquid volume - V _G dispersed gas volume - V _G ^* gas throughput at the gas distributor (given in m³/h) under standard conditions, 1 bar and 25°C) - V _G,d ^* gas throughput in downcomer (=V _G ^* ) - V _G,h ^* gas throughput in head (=V _G ^* ) - V _G,r ^* gas throughput in riser (V _G ^* (1+) - w _g gas velocity - w _G,rel relative gas velocity with respect to the liquid velocity w _L - w _G,d gas velocity in the downcomer (=w _G,rel –w _Ld ) - w _G,h gas velocity in the head (=w _G,rel ) (since wLh = o) - w _G,r gas velocity in the riser (=w _G,rel +w _Lr ) - w _L liquid velocity - w _L,d liquid velocity in the downcomer measured with mass flow meter - w _sg ·w _SL superficial gas and liquid velocities - first moment of the response curve - mean residence time Indices d downcomer - G gas phase - h head - L liquid phase - r riser - h hydrodynamic (upper position) Dedicated to the 65th birthday of Proffessor Fritz Wagner.The authors gratefully acknowledge the financial support by the Krupp Industrietechnik, Grevenbroich and the support of Pleser Co, Darmstadt. H. M. Rüffer thanks the Verband der Chemischen Industrie for a Fond der Chemie scholarship, and W. Liwei thanks the government of Lower Saxony for a graduate scholarship.     

天然林内红松种群年龄更替数学模型及研究

本文给出天然林内红松种群年令更替数学模型（1）。通过对（1）进行定性分析,得到主要结论是：系统（1）在第一象限内存在唯一稳定周期解的充要条件是bk-bc-2d＞0其生态意义是天然林内红松幼树与母树随时间变化会产生一个有规律、互为消涨的变化特征。     

内蒙古大青山豹蛛属1新种（蜘蛛目：狼蛛科）

记述采自内蒙古自治区大青山地区的狼蛛科Lycosidae豹蛛属Pardosa一新种:大青山豹蛛Pardosa daqing shanica sp.nov.     

大鼠脑神经元特异性烯醇化酶基因的cDNA克隆及序列分析

用ＲＴ－ＰＣＲ方法快速克隆了Ｗｉｓｔａｒ大鼠脑神经元特异性烯醇化酶（ＮＳＥ）的ｃＤＮＡ,将此包括编码全长ＮＳＥ４３３个氨基醚的ＤＮＡ片段重组入ｐＵＣ质粒,并用ＰＣＲ方法测定了全部顺序,经重复实验,发现Ｗｉｓｔａｒ大鼠与Ｆｏｒｓｓ－Ｐｅｔｔｅｒ报导的ＳＤ大鼠ＮＳＥ基因顺序,有两外单碱基的差别,其中一个涉及氨基酸的改变。同时还对ＲＮＡ的提取及长片段ＤＮＡ的ＲＴ－ＰＣＲ扩增进行了方法学的探讨。