Materials for the genus Lycopodium L. in Prov. Sichuan,China

In the present paper several species of Lycopodium L. from Sichuan, West China, are enumerated, of which 4 are described as new. They are: L. emeiense Ching et H. S. Kung, L. nanchuanense Ching et H. S. Kung, L. crispatum Ching and L. kangdingense Ching. In the course of this study, the writer has tried as much as he could to review rather exhaustively all the Lycopodium species of the province published sporadically in the literature in the past and their identity is established on the basis of rich materials available, thus a number of mistakes by earlier authors being revised. My thanks are due to the comrades of herbaria of many botanical institutions and universities for their friendly co-operation, and to Prof. R. C. Ching of the Instituteof Botany, Academia Sinica, under whose guidance the present study was carried out.     

Overfishing of top predators eroded the resilience of the Black Sea system regardless of the climate and anthropogenic conditions

It is well known that human activities, such as harvesting, have had major direct effects on marine ecosystems. However, it is far less acknowledged that human activities in the surroundings might have important effects on marine systems. There is growing evidence suggesting that major reorganization (i.e., a regime shift) is a common feature in the temporal evolution of a marine system. Here we show, and quantify, the interaction of human activities (nutrient upload) with a favourable climate (run‐off) and its contribution to the eutrophication of the Black Sea in the 1980s. Based on virtual analysis of the bottom‐up (eutrophication) vs. top‐down (trophic cascades) effects, we found that an earlier onset of eutrophication could have counteracted the restructuring of the trophic regulation at the base of the food web that resulted from the depletion of top predators in the 1970s. These enhanced bottom‐up effects would, however, not propagate upwards in the food web beyond the zooplankton level. Our simulations identified the removal of apex predators as a key element in terms of loss of resilience that inevitably leads to a reorganization. Once the food web has been truncated, the type and magnitude of interventions on the group replacing the apex predator as the new upper trophic level have no effect in preventing the trophic cascade. By characterizing the tipping point at which increased bottom‐up forcing exactly counteracts the top‐down cascading effects, our results emphasize the importance of a comprehensive analysis that take into account all structuring forces at play (including those beyond the marine system) at a given time.     

中国后生耳蕨组的孢子形态研究

对国产耳蕨属后生耳蕨组２６种的孢子形态进行了研究。结果表明,后生耳蕨组的孢子周壁纹饰可大致分为粗糙、翅状、脊状、穴状和网状６类。各种的周壁纹饰均有一定差异,同种的孢子形态较为稳定。从孢子形态特征看,支持Ｐｏｌｙｓｔｉｃｈｕｍ ｙｕｎｎａｎｅｎｓｅ Ｃｈｒｉｓｔ和Ｐｊｉｚｈｕｓｈａｎｅｎｓｅ Ｃｈｉｎｇ为独立的种。本文还结合其它特征,讨论了后生耳蕨组孢子形态的演化趋势,进而从孢粉学的角度推测本组线鳞     

Efficient Expression of the Paramecium Calmodulin Gene in Escherichia coli after Four TAA-to-CAA Changes through a Series of Polymerase Chain Reactions

We have expressed the Paramecium calmodulin gene in Escherichia coli by changing the four TAA codons in this gene to CAAs. This was carried out by three polymerase chain reactions (PCRs) and then cloning the product into the expression vector pKK223-3 immediately downstream of its trp-lac hybrid promoter. JM109 strain of E. coli , transformed with the recombinant plasmid harboring the altered Paramecium calmodulin gene, produces a protein judged to be calmodulin. It is recognized by a monoclonal antibody to Paramecium calmodulin; it migrates with the native protein at nearly the same rate in electrophoreses; and it shows a Ca²⁺-dependent shift in electrophoretic pattern. The production of calmodulin is about 170 times as efficient with E. coli as with Paramecium in terms of unit volume of packed cells, and is about 400 times as efficient in unit volume of liquid culture. This method appears useful in site-directed mutageneses and in the heterologous productions of other ciliate proteins. A critique of this method is provided. A calmodulin half-molecule, a by-product of this project, is described.     

人细胞周期相关激酶启动子的克隆和初步分析

克隆人的细胞周期相关激酶(CCRK)基因启动子,分析与其表达有关的转录调控因子。通过巢式PCR方法,从人的基因组总DNA中分离出CCRK基因5′端非翻译区大小为1072bp的片段。这段片段的3′端起始点在第一个外显子里第一个翻译密码子ATG( 1)上游128bp处。以1072bp为模板,对启动子进行5′端删除分析,分别扩增951bp(-1072／-128)、564bp(-692／-128)、313bp(-441／-128)、127bp(-239／-128)的片段,与pGL3-Basic荧光素酶报告载体重组构建,人工加上克隆位点,5′端带有KpnI、3′端带有XhoI位点。瞬时转染恶性神经胶质瘤细胞株U373,通过双荧光素酶活性进行分析。对分离出的1072bp的片段进行测序,结果与GenBank(Accession AF035013)的序列比较,同源序列达到98％。双荧光素酶活性分析564bp片段有最强的活性,313bp片段为有活性的最小片段。本研究为进一步研究分析CCRK的核心启动子和与其相关的转录因子奠定基础。     

日本血吸虫尾蚴头器、腺体及体被超微结构的观察

本文报告用扫描与透射电镜观察大陆品系日本血吸虫(Schistosoma japonicum)尾蚴的头器、膆体及体被的超微结构。 从不同角度扫描电镜观察日本血吸虫的尾蚴头器前端,见有5对钻腺的开口,开口的周围有围褶,围褶的外侧分布有7对无鞘单纤毛的感觉乳突,这些结构靠近头器的腹侧围成马蹄形,顶端为无棘区。作者综合有关图像重建日本血吸虫尾蚴头器表面结构的示意图,供参考。 日本血吸虫尾蚴的体被、头腺及钻腺与曼氏血吸虫尾蚴基本相似,但在前钻腺分泌小体我们另见有连续性条索状透明物,对它的形成及其性质进行了讨论。     

广西咖啡树两种虎天牛的研究

咖啡是我区解放以后栽植的热带经济作物,随着栽植时间的增长和咖啡园林的形成,各种害虫相继繁殖孳生为害。据多年调查,已发现我区咖啡树上害虫约有50种,其中钻蛀性的虎天牛发生普遍,具有毁灭性。幼虫钻蛀为害后,轻者叶黄枝枯,产量锐减;重则主干折断而至整株枯死,颗粒无收。因此,寻求经济有效的防治措施是急待解决的任务。1958年以来,我们即开始进行了调查试验,近又有所补充,今将结果报道如下。