遗传物质的发现者之一——麦卡锡

1944年,3位科学家艾弗里、麦卡锡和麦克劳德在DNA遗传本质方面的发现是20世纪最重要的发现之一,这个发现打开了生物学革命的大门,从而改变了人类对自然界的看法,这项研究还为1953年沃森和克里克DNA双螺旋结构的发现奠定了坚实的基础,但不幸的是3位科学家都未曾荣获诺贝尔奖.通过介绍麦克林·麦卡锡的科学研究,从而对这项发现的基本状况有一个基本的了解.     

苏联猛犸象的研究

猛犸象(Elephas primigenius)是最著名的动物化石之一。在欧洲,西伯利亚,中国北部以及其他区域内的许多地方,都曾发现过大批这种动物的遗体,而且它们的庞大的躯体与奇特的形状早就吸引了人们的注意。此外,在亚洲及欧洲的冻土带内,曾发现过这种动物的,连皮,肉和毛都保存着的完整的尸体。古代极北地区的居民,当他们发现了这些由于海岸崩裂而从地下深处露出来的尸体后,曾企图寻求关于这些奇怪动物的外貌的解释。在耶库     

丘脑-皮层感觉通路上的反馈调节

皮层投射到丘脑的纤维数量约为丘脑至皮层的纤维数量的10倍,因此许多研究者都认为这一庞大的反馈网络必然在感觉信息的加工过程中发挥着重要的作用,而越来越多的证据也显示,来自皮层的反馈调节在修整丘脑反应方面起到了非常关键的作用.本文即从解剖学和生理学的角度对皮层.丘脑反馈调节的相关研究做一简要综述.     

c-Cbl介导了hSef的泛素化和降解

Sef(similar expression to fgf genes)作为FGF信号通路中可诱导的拮抗分子相继在斑马鱼,小鼠,和人类中被鉴定出来,并进行了相应的功能研究.目前对于Sef蛋白本身稳定性的研究还未见报道.对c-Cbl对Sef稳定性的影响进行了研究.免疫荧光实验表明Sef能够和c-Cbl蛋白在细胞中发生共定位,随后的免疫共沉淀实验证明Sef能够和c-Cbl发生相互作用.体内泛素化实验表明c-Cbl能够使Sef发生明显的泛素化作用.这种泛素化最终导致了Sef本身的剂量依赖性的降解.针对c-Cbl的siRNA表达也使Sef稳定细胞系的表达水平得到恢复.结果表明,c-Cbl对Sef的泛素化及降解可能作为一种调控拮抗因子的蛋白质水平从而最终调节信号通路的一种机制.     

远古人类的狩猎武器

当你走进中国科学院古脊椎动物与古人类研究所内中国古动物馆的树华古人类馆,你注意到展柜里那些圆形的石头标本了吗?这就是10多万年前古人类狩猎与防身的武器——石球.与现在的手枪、步枪和机关枪的子弹和大炮的炮弹等异曲同工的是,这些远古社会古人类使用的石球是一种远距离杀伤武器.     

脑电图数据的相关性分析

目的:本文对客观记录的脑电图数据进行相关性分析,为正确理解人脑的不同局部以及局部与整体之间的相关性提供基础实验依据和理论根据,为脑电图研究的其它分析做基础分析.方法:分别对10导联电极和21导联电极的两组脑电图数据做互相关和自相关的相关性分析,得出在不同条件、事件下脑的各导联电极的自相关分析结果和左右对称导联电极的互相关分析结果,最后得出相关性值随实验条件和事件的具体变化.数据处理和统计分析采用独立设计的脑电图分析工具箱和相关性分析程序.结果:脑电图数据经过相关性分析后得到的相关图具有和脑电波相似的波形,具有周期性,时间滞后对应的标准化的相关图显示出相关性值的第一个主峰是最大的,主峰频率一般在8到13Hz的脑电波频段内;最后得到的相关性值随事件的变化而改变的结果说明实验事件对相关性的影响.结论:自相关和互相关都是随着时间滞后的增大而逐渐减小;波具有较强的相关性;相关图在从零延迟开始时间滞后所出现的第一个波峰是主峰,反应出相对较强的相关性;从大量数据的分析最后得到的相关性与事件的关系表明相关性是受事件影响的.     

高黎贡山北段东西坡种子植物区系的比较研究

高黎贡山北段的东西坡由于在降雨量和热量分配等方面存在着显著的差异,致使东西坡在植物的种类、组成及区系特征等方面表现出明显的差异.东坡记载野生种子植物152科,580属,1475种及192变种(亚种),西坡记载野生种子植物162科,659属,1804种及186变种(亚种).东西坡种子植物科、属、种的对比分析表明:1)东西坡现代种子植物区系具有相同的历史渊源,但其区系联系减弱了,东西坡区系相似性程度,依科、属、种的顺序依次递减;2)西坡现代种子植物区系比东坡具有更为深刻的热带起源烙印.就科、属、种三个水平来说,东坡的热带成分低于西坡,温带成分高于西坡.许多典型的泛热带大科在西坡比东坡有着更为丰富的种类,其中有些泛热带科分子在东坡缺乏分布,而在西坡找到了合适的驻留之地;3)西坡现代种子植物区系与东喜马拉雅植物区系的联系比东坡紧密,而东坡与高黎贡山以东的区系联系比西坡密切,由于高黎贡山山脉的阻隔,近代植物物种的东西坡交流发生了障碍;4)西坡生态地理环境比东坡更有利于物种的生存、繁衍和分化,它既是古老成分的避难所,又是孕育新生成分的摇篮.     

鸡的瞬膜

瞬膜(nictitating membrane),又称第三眼睑,是一种保护眼球、防止灰尘的结构.鸟类的瞬膜位于眼眶的前眼角,为半透明的膜,其内缘具有一种羽毛上皮,借以刷洗角膜上的灰尘.在飞行时能遮覆眼球,以避免干燥气流和灰尘对眼球的伤害.由于瞬膜在鸟类睁眼的一瞬间迅速缩回前眼角,很难拍摄到.最近费了好大的周折,终于拍到了理想的鸡瞬膜照片,现予以发表供生物学界的同行共享(友情提示:如引用请注明原作者).     

江西考古的结缘地——安义

正友情笔者从事史前考古学已40余年,让我最难忘的是与江西安义县文物爱好者胡贤钢的友情,这种友情还需从1988年讲起。当年,胡贤钢20岁,是安义县食品厂的一名工人。他勤奋好学,对历史文化有着浓厚的兴趣。他从中学历史书中掌握的一些史前学知识,来了解远古人类使用过的生产和生活工具。在休假的时候,他常常在自己家乡的丘陵和台地采集古人类使用过的工具来收藏。当时他的家庭人口多,经济拮据,但是他喜欢读书,他的父母支持他的爱好,舍得花钱给他买一些书。1988年在县的新华书店曾花一角钱,     

叶绿体基因组研究进展

作为植物细胞器的重要组成部分和光合作用的器官,叶绿体在生物进化的漫长历史中发挥了重要作用.伴随着生物技术的深入发展,人们发现叶绿体基因组结构和序列的信息在揭示物种起源、进化演变及其不同物种之间的亲缘关系等方面具有重要价值.与此同时,比核转化具有明显优势的叶绿体转化技术在遗传改良、生物制剂的生产等方面显示出巨大潜力,而叶绿体基因组结构和序列分析则是叶绿体转化的基石.基于叶绿体的这些重要作用,收集整理了有关的资料,从几个方面归纳了本领域最近的研究进展,希望能使读者对迅速发展的叶绿体基因组研究有更全面的了解,以及对叶绿体基因组在物种的进化、遗传、系统发育关系等方面的作用有更深刻的认识,同时也希望对叶绿体转化技术的研究和广泛应用产生积极作用.     

温带地区表土植硅体对温度的响应

植硅体的现代过程研究是利用植硅体这一指标精准恢复区域古植被、古气候的前提和关键环节,探讨表土植硅体组合的空间分布特征及其对环境因子的响应尤为重要.本研究在东北地区沿着年降水量为600 mm等降水线采集54块表土样品,研究单一温度控制下表土植硅体的空间分布规律,以期寻找对温度比较敏感的植硅体类型.结果表明:54块表土样品...     

Comparing development with physical fitness, motor ability, and health of children among various living environment

This study had the purpose to compare with development of fitness, motor ability and health among various living environments of the sea-side, the urban, and the mountain districts, where were situated at Nadachi town on the suburbs of Niigata Prefecture. Five hundred thirty-five children (aged 4-15 yrs) were measured at the kindergarten, the fundamental school, and the junior high school. Measuring items of the physique were the height, the weight, the chest circumference, the sitting height, and the foot area. Physical fitness tests were the muscular grip-strength, the lung vital capacity, the closed-eye single-leg balance, the dipping time of the upper extremity, the vertical jump, the standing trunk flexibility, the endurance run, and pull-up. And, motor ability tests were the finger tapping, 5m shuttle run, 50m dash, and the ball throwing. As items of health inspection, the blood pressure (systolic and diasystolic) and the visual ability were adopted. As results of this study, following data were obtained; 1) At the sea-side environment, development of the muscle power, the respiratory function, and the physique were showed much faster rate of growth at the childhood than that of the other ones, significantly (P less than 0.01). 2) At the mountain environment, the arch-bend of the foot print only were appeared larger areas than that of the other ones, significantly (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

长白山某些树种叶子的分解动态研究

 在长白山针阔叶混交林下,红松、蒙古栎、春榆、白桦、山杨、色木及紫椴叶分解至300天时,其重量损失百分数分别为24.2,37.6,30.8,44.47,50.6及55.6。在分解过程中,每种叶子的重量损失同该叶子的木质素、水溶性物质、全碳及全氮的变化成线性相关(R=0.99**)。在叶子分解前期,木质素、N素的绝对量有所增加,而水溶性物质则急剧减少。除紫椴叶外,其它几种叶子在分解过程中氮的含量有一定增加。但是,当红松、蒙古栎、春榆、白桦、山杨及色木叶中N素浓度分别为0.96%,1.41%,2.38%,1.67%,1.32%及1.32%时,则开始了N素的矿化释放。     

Integrated population genetic and medical genetic study of two raions of the Tver oblast

An integrated medical genetic an population genetic study has been performed in two raions (administrative districts) of the Tver oblast (region) of Russia: the Udomlya raion located in the zone affected by the Kalininskaya Nuclear Power Plant and the Ostashkov raion, which served as a control district. No significant differences has been found with respect to the genetic parameters studied. The values of these parameters in the populations of the town of Udomlya, the town of Ostashkov, the Udomlya raion, and the Ostashkov raion, respectively, are the following: random inbreeding, 0.00006, 0.00011, 0.000167, and 0.000366; endogamy index, 0.05, 0.43, 0.30, and 0.42; local inbreeding, 0.0003, 0.00045, 0.0009, and 0.0011; the degree of isolation by distance, 0.0003, 0.00045, 0.0009, and 0.0005; sigma, 2098, 1338, 1473, and 1189; the load of autosomal dominant (AD) diseases, 0.71, 0.92, 0.92, and 1.37; the load of autosomal recessive (AR) diseases, 0.68, 0.69, 0.67, and 0.82; and the load of X-linked diseases, 0.18, 0.64, 0.83, and 0.27.     

青藏高原白垩纪双壳类生物地理

青藏高原白垩纪沉积见于６条东西向延伸的条带内。双壳类主要发育于这些条带的Ｂｅｒｒｉａｓｉａｎ,Ａｐｔｉａｎ－Ａｌｂｉａｎ,Ｃｅｎｏｍａｎｉａｎ－Ｔｕｒｏｎｉａｎ,Ｃｏｎｉａｃｉａｎ－Ｓａｎｔｏｎｉａｎ和Ｃａｍｐａｎｉａｎ－Ｍａａｓｔｒｉｃｈｔｉａｎ５个时期的地层。雅鲁藏布江缝合线为白垩纪双壳类地理分布的主要控制界线。早白垩世期间,雅鲁藏布江缝合带以南的喜马拉雅地区的双壳类Ｐｅｔｒｏｃｅｒａｍｕｓ,     

生境空气质量测定与评价指标

该指标系统规定了空气生境指数(Air entironment index,简称AEI)、生境空气质量分级、采样点及取值时间,采样与分析方法及数据统计的有效性规定。空气生境指数(AEI)的测定与评价的十个项目:空气洁净度(CI)、空气新鲜度(T)、植物精气浓度、人均绿地面积、绿地植物覆盖率、硬质覆盖率、水体覆盖率、界外植物覆盖率、移植植物树龄或原生植物树龄、植物种类和植物景观。本手册适用于住区生境空气质量评价。住区生境空气质量分为五级:5A级空气质量住区;4A级空气质量住区;3A级空气质量住区;2A级空气质量住区;1A级空气质量住区。     

The effect of neurotropic substances on the self-stimulation reaction at the thalamic level]

The effect of d-amphetamine, cocaine, caffeine, morphine, imipramine, phenobarbital, LSD-25, benactyzine, meprobamate, diazepam, chloridiazepoxide on the lateral hypothalamic self-stimulation of rats was investigated. D-amphetamine, cocaine, caffeine, morphine, imipramine decreased the threshold of selfstimulation. Meprobamate, diazepam, chlordiazepoxide failed to influence this index, but increase the intensity of self-stimulation during the threshold, the optimum and more than the optimum cirrent intensity. Benactyzine, LSD-25, phenobarbital decreased the threshold and increased the frequency of self-stimulation during all the current intensities. A comparative study of the above results showed the agents of the first group to exert a direct stimulating action on the positive reinforcement system. Tranquillizers activated this system due to their depressive action on the negative reinforcement system. Benactyzine, LSD-25, phenobarbital activated the system and depressed the system of negative reinforcement.     

洞庭湖流域中上游地区景观格局变化的水文响应

将洞庭湖流域中上游地区1980、1995和2000年的Landsat MSS和TM卫星照片解译所得的景观数据,与经过最大似然估计法“消噪”的湘、资、沅、澧四水入湖水文站的年内最高洪峰水位、最大瞬时流量、年入湖径流量和年入湖泥沙量数据进行Paneldata模型处理,并对处理后的景观和水文数据进行灰色分析和主成分分析。结果表明：研究区最高洪峰水位的变化受景观格局变化影响最大,入湖泥沙量的变化受景观格局变化影响最小。对最高洪峰水位变化影响最大的是山地水田、水库坑塘和灌木林地疏林地景观面积的变化,影响指数值分别达-48．5、-48．1和45．2;对最大瞬时流量变化影响最大的是水库坑塘、水田（山地水田除外）和灌木林地疏林地景观面积的变化,影响指数值分别达-41．9、41．2和41．2。有林地景观因林分差和林种结构单一,对各水文特征指标变化的影响较小,影响指数值分别仅为-10．1、-13．5和-14．5。     

Immunohistochemical mapping of galanin-like neurons in the rat central nervous system

Using an antiserum generated in rabbits against synthetic galanin (GA) and the indirect immunofluorescence method, the distribution of GA-like immunoreactive cell bodies and nerve fibers was studied in the rat central nervous system (CNS) and a detailed stereotaxic atlas of GA-like neurons was prepared. GA-like immunoreactivity was widely distributed in the rat CNS. Appreciable numbers of GA-positive cell bodies were observed in the rostral cingulate and medial prefrontal cortex, the nucleus interstitialis striae terminalis, the caudate, medial preoptic, preoptic periventricular, and preoptic suprachiasmatic nuclei, the medial forebrain bundle, the supraoptic, the hypothalamic periventricular, the paraventricular, the arcuate, dorsomedial, perifornical, thalamic periventricular, anterior dorsal and lateral thalamic nuclei, medial and central amygdaloid nuclei, dorsal and ventral premamillary nuclei, at the base of the hypothalamus, in the central gray matter, the hippocampus, the dorsal and caudoventral raphe nuclei, the interpeduncular nucleus, the locus coeruleus, ventral parabrachial, solitarii and commissuralis nuclei, in the A1, C1 and A4 catechaolamine areas, the posterior area postrema and the trigeminal and dorsal root ganglia. Fibers were generally seen where cell bodies were observed. Very dense fiber bundles were noted in the septohypothalamic tract, the preoptic area, in the hypothalamus, the habenula and the thalamic periventricular nucleus, in the ventral hippocampus, parts of the reticular formation, in the locus coeruleus, the dorsal parabrachial area, the nucleus and tract of the spinal trigeminal area and the substantia gelatinosa, the superficial layers of the spinal cord and the posterior lobe of the pituitary. The localization of the GA-like immunoreactivity in the locus coeruleus suggests a partial coexistence with catecholaminergic neurons as well as a possible involvement of the GA-like peptide in a neuroregulatory role.     

Screening of Native Hyperaccumulators at the Huayuan River Contaminated by Heavy Metals

Plant, soil, and sediment samples were taken from the Fuqiao area within the Huayuan River basin in South China. Concentrations of manganese, zinc, cadmium, and lead in the samples were measured, and the characteristics of the plant samples to absorb, transfer, and accumulate the target metals were analyzed. It was indicated that the concentrations of target metals in 13 plant samples greatly exceeded the background values of target metals in plants over the world, and that the plant species might evolve to the accumulating ecotypes for the target metals under the long-term stress from the contaminated environment. Among 13 plant species, Alternanthera philoxeroides exhibited the highest accumulation capacities for the target metals, amounting to 6511, 13,784, 155, and 104 mg/kg in its shoots for manganese, zinc, cadmium, and lead, respectively. Its bioaccumulation coefficients for manganese, zinc, cadmium, and lead were 5.08, 49.23, 36.78, and 34.81, respectively, and its transfer factors for manganese, zinc, cadmium, and lead were 7.53, 3.19, 7.38, and 1.29, respectively. The results showed that Alternanthera philoxeroides satisfied the criteria for the hyperaccumulator for zinc and cadmium, and that it might be a potential native plant species for phytoremediation of the contaminated soil, sediment, and river water by the target metals within the basin.