The identity of Schizothorax griseus Pellegrin, 1931, with descriptions of three new species of schizothoracine fishes (Teleostei: Cyprinidae) from China

The identity of Schizothorax griseus Pellegrin, 1931, is clarified and the species redescribed. Three new species previously identified as S. griseus are described: S. nudiventris, from the Lancang Jiang, China; S. heterophysallidos, from the Nanpan Jiang

Molecular Mechanics Simulation of Recognition Identity of tRNA~(His/GUG)

本文选用经过实验验证的碱基序列 ,用简化的方式 ,构建了被水分子和镁离子修饰的核酸序列的分子模型 ,应用分子力学模拟方法对序列进行能量优化 ,对优化后序列的构象参数、成键状况和能量数据等进行了分析。对tRNAHHis GUG的识别特性作了初步的探索 ,得到了和实验结果相近的结论。此外 ,还从能力学的角度讨论了溶剂 -溶质 -溶剂相互作用形成的网状氢键网络对核酸结构稳定性的影响 ,探讨了非Crick_WatsonGU、UU配对的能力学特征并存在于被水分子和镁离子修饰的核酸序列中的GU、UU配对情况。

Molecular systematics of medusae in the genus Craspedacusta (Cnidaria: Hydrozoa: Limnomedusae) in China with the reference to the identity of species

The objective of this study was to illustrate the phylogenetic relationship of the species in the genus Craspedacusta in China. The medusae samples were collected at 28 localities in China representing seven described species with their entire ITS region (the contiguous sequences of ITS-1, 5.8S and ITS-2 rDNA) rDNA sequences cloned. Among the 28 samples, the range of sequence variation in the complete ITS and 5.8S region was between 0 and 36.2%. Three main clades were revealed by both maximum likelihood and neighbour-joining trees, with sequence difference of 0-0.9, 0-3.7 and 0.1-1.5% in the three clades. The nesting of C. xinyangensis representatives within C. sowerbii, C. brevinema within C. sinensis and C. sichuanensis within C. kiatingi is strongly supported, with interspecific sequence divergence of 0-0.9, 0.1-1.4 and 0.0-0.4%, respectively. Thus, it is suggested that C. xinyangensis should be the synonym of C. sowerbii, C. sichuanensis the synonym of C. kiatingi and C. brevinema the synonym of C. sinensis. However, the taxonomic status of C. ziguiensis is still uncertain. According to the tree topology, C. kiatingi was closer to C. sowerbii than to C. sinensis. Craspedacusta sinensis was the most genetically distinct from distance matrix values, and located at the base of the phylogenetic trees, so it can be speculated that the C. sinensis may be the ancestral form in the genus Craspedacusta.

BRST quantization and canonical Ward identity of the supersymmetric electromagnetic interaction system

According to the method of path integral quantization for the canonical constrained system in Becchi-Rouet-Stora-Tyutin scheme, the supersymmetric electromagnetic interaction system was quantized. Both the Hamiltonian of the supersymmetric electromagnetic interaction system in phase space and the quantization procedure were simplified. The BRST generator was constructed, and the BRST transformations of supersymmetric fields were gotten; the effective action was calculated, and the generating functional for the Green function was achieved; also, the gauge generator was constructed, and the gauge transformation of the system was obtained. Finally, the Ward-Takahashi identities based on the canonical Noether theorem were calculated, and two relations between proper vertices and propagators were obtained.

Structure and identity of 4,4 '-thiobisbenzenethiol self-assembled monolayers

Self-assembled monolayers (SAMs) of 4,4'-thiobisbenzenethiol (TBBT) can be formed on Au surface spontaneously. The structural characteristics and adsorption behavior of TBBT SAMs on Au have been investigated by surface enhanced Raman scattering (SERS), electrochemical cyclic voltammetry (CV), ac impedance spectroscopy (EIS), and atomic force microscopy (AFM). It is demonstrated that TBBT adsorbed on Au by losing a H atom, forming one Au-S bond, and the other mercapto group is free at the surface of the monolayer owing to the presence of the nu(S-H) at 2513 cm(-1) and the delta(C-S-H) at 910 cm(-1) in SERS. The enhancement of the vibration of C-S (1064 cm(-1)), the aromatic C-H vibration (3044 cm(-1)), and the absence of the vibration of S-S illustrate TBBT adsorbed on Au forming a monolayer with one benzene ring tilted with respect to the Au surface. The interpretation of the observed frequencies is aided by ab initio molecular orbital (MO) calculations at the HF/6-31G* level of theory. Electrochemical CV and EIS indicate TBBT monolayers can passivate the Au effectively for its low ratio of pinhole defects (theta = 99.6%). AFM studies give details about the surface morphology. The applications of TBBT SAMs have been extensively investigated by exposure of Cu2+ ion to TBBT SAMs on Au and covalent adsorption of metal nanoparticles.

Assessing genetic identity of sporophytic offspring of the brown alga Undaria pinnatifida derived from mono-crossing of gametophyte clones by use of amplified fragment length polymorphism and microsatellite markers

The haploid stage of gametophytes of the subtidal brown alga Undaria pinnatifida can be vegetatively propagated under favorable conditions. This unique characteristic makes it possible to establish independent gametophyte cell lines that are zoospore-derived. Sporophytic offspring can be generated through hybridizing the male and female gametophytes, which are derived from different cell lines. Accumulated experiences in this and other species in Laminariales demonstrated the applicability of this novel way to breed desired strains for open-sea cultivation. Sporophytic offspring originated from mono-crossing of male and female gametophyte clones were shown to have similar morphological characteristics under identical ambient conditions. However, there has been no report to relate this similarity on molecular levels. In this report, amplified fragment length polymorphism (AFLP) and microsatellite markers were used to analyze the genetic identity of sporophytic offspring of U. pinnatifida originated from two mono-crossing lines (M1 and M2), two self-breeding lines (S1 and S2) and one wild population (W). Totally 318 AFLP loci were revealed by use of 11 primer sets, of which 4.7%, 0.3%, 17.9%, 16.4% and 36.5% were polymorphic in M1, M2, S1, S2 and W, respectively. The pairwise genetic identity among the individuals of the same line was assessed. It was shown that offspring from mono-crossing lines had a higher degree of identity (95.6-100%) than self-breeding lines (87.7-98.4%) and the wild population (81.5-92.1%). Analysis by use of six microsatellite loci also revealed a higher genetic identity among individuals of the mono-crossing line, further confirming the results of AFLP analysis. Results from this investigation support, on molecular levels, the novel way to produce and maintain strains in U. pinnatifida by use of different gametophyte cell lines.