Three new species of misophrioid copepods from oceanic islands

Three new species of misophrioid copepods are described from anchialine habitats on oceanic islands. Expansophria galapagensis n.sp. is described from two localities on Santa Cruz, Galapagos Islands, Speleophria campaneri n.sp. from Ngamduk Cave, Angaur Island, Palau and S. scottodicarloi n.sp. from Chalk Cave on Bermuda.     

Accurate localization and excision of genomic islands in four strains of <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> and <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis>

Mobile genomic islands (GIs) can be excised from the chromosome, then form a circular intermediate and be reintegrated into the chromosome by the GI internal integrase. Some mobile GIs can also be transferred into a new receptor cell by transformation, conjugation, or transduction. The action sites of the integrase are usually flanked direct repeats (DRs) of the GIs. Accurate localization of the flanking sequences is a precondition for determining the mobility of the GI. Mobile GIs are generally associated with transfer RNAs (tRNAs). Based on the correlation between flanking sequences and tRNA sequences, the flanking sequences of 11 putative mobile GIs in Pseudomonas aeruginosa PAO1, P. aeruginosa PA14, P. fluorescens Pf-5 and P. fluorescens Pf0-1 were identified. Among the 11 GIs, Pf0-1GI-1 is responsible for benzoate degradation. PAO1GI-1, Pf5GI-2, Pf5GI-3, and Pf5GI-4 were confirmed experimentally to be excised from a chromosome to form a circular intermediate. The action sites of the integrases are these GIs direct repeats. Due to distinct DRs, cutting sites for the internal integrase of PAO1GI-1, Pf5GI-2, Pf5GI-3 and Pf5GI-4 were determined outside the T-loop of the tRNA^Gly gene, outside the anticodon loop of the tRNA^Ser gene and tRNA^Lys gene, and at the asymmetric 3′-end of the tRNA^Leu gene, respectively. PAO1GI-1 and other mobile GIs may be transferred into many different strains that belong to different phyla because of the clear flanking sequences. This study describes basic information about the action sites of the integrases, assesses the mobility of GIs, and can help design and transfer mobile GIs to candidate strains.     

Subspeciation or none? The hardun in the Aegean (Reptilia: Sauria: Agamidae: Laudakia stellio)

A study aimed at testing the contested validity of the subspecies Laudakia stellio daani yielded novel insights into the essence of subspecies. We examined morphologically museum specimens from Greece, Aegean islands, and Anatolia (n?=?118; not all could be used in all analyses). Beyond the conventional mensural, meristic and qualitative characters we quantified 14 coloration characters, thus totalling 34 characters (including sex). Biometry was statistically analysed within and between the two geographically defined presumed subspecies, L. s. daani and L. s. stellio. Excluding or including broken‐tailed specimens changed the outcome of tests. Significant minor directional asymmetry occurred in one of four character‐taxon combinations. Phenetic cluster analysis poorly separated the two presumed subspecies when all characters, including those with discordant variation, were included; after selection of characters, the separation improved. Some biometric characters distinguish the two presumed subspecies, confirming their validity. The associations of significant inter‐character correlations differed between the two subspecies. Additionally, the two differed in parameters reflecting selection pressures and social structure: L. s. stellio is more colourful than L. s. daani; its sexual dimorphism is mainly chromatic, versus mensural in L. s. daani; and its population seems to include many males with underdeveloped callous scales, presumably socially subordinate, versus very few in L. s. daani.     

接合转座子Tn916的水平基因转移

水平基因转移（HGT）极大地提高了细菌物种对环境的适应性,促进了细菌的进化.原核生物通过水平基因转移获得的基因片段为基因岛（GEIs）.接合转座子（CTns）则是一种常见的可移动基因岛,通过接合进行水平基因转移,并主要传播抗生素抗性.该文介绍与讨论了一种发现较早,且被广泛研究的接合转座子Tn916的重组、接合转移和调控模块,阐述了这类接合转座子的一般结构、转移机制和影响.     

《死の棘》：战争文学的文本

岛尾敏雄是日本有名的战后派作家之一。《死の棘》是他历时17年完成的一部以家庭生活经历为题材的长篇小说。一直以来,这部小说被当成私小说进行论述、分析。虽然这是一部描写家庭生活的作品,但是第二次世界大战结束前夕,作者作为特攻队队长的战争经历却与这部作品的创作背景息息相关,通过作者与战争经历和南岛的关系,可以将其作为战争文学来解读。     

日本列岛气候纬向地带性分异规律的顺归分析

气候的纬向地带性是地球表面最基本的分异规律,温度的差异是纬向地带性的重要的标志．本文主要是通过任意选取的日本列岛不同自然带中的13个测站的月均温与纬度值,运用数理统计中回归分析的方法对日本列岛的气候纬向地带性的分异规律做出了定量分析,进而扩展到对于世界各地的气候的纬向地带性分析都可采用这种定性和定量分析相结合的方法来研究．     

庙岛群岛南部岛群无居民海岛植被净初级生产力评估

无居民海岛具有显著的战略地位和重要的生态价值,植被净初级生产力(NPP)评估对维护无居民海岛生态系统稳定性和活力具有重要意义.以庙岛群岛南部岛群中螳螂岛等5个无居民海岛为研究对象,通过遥感手段,对海岛NPP总量和密度及其空间分布特征进行分析.结果显示：1) 全年NPP总量为134.22 tC·a－1,平均密度为274.13 gC·m－2·a－1,并表现出明显的季节差异,各岛NPP平均密度由大到小依次为牛砣子岛、羊砣子岛、螳螂岛、南砣子岛和挡浪岛;2) 不同地表覆盖类型NPP平均密度由大到小依次为阔叶林、针叶林、草地、建设用地和裸地,各岛NPP平均密度与裸地面积占比呈明显的负相关,区域NPP密度与海拔、坡度、坡向和归一化植被指数呈显著正相关;3) 黑松和刺槐是北方无居民海岛人工林的理想树种,持续的人工林种植是提升无居民海岛NPP的重要途径.     

回火温度对低碳贝氏体高强度钢组织性能的影响

利用光学显微镜、扫描电镜、透射电镜和力学性能试验机等手段,系统研究了不同回火温度下低碳贝氏体高强度钢的组织及力学性能变化.结果表明:回火后位错密度的变化、析出相的形态、板条贝氏体的合并粗化和M/A岛的分解是导致力学性能变化的主要原因.600℃回火后屈服强度较热轧态强度提高了35MPa,-40℃冲击功提高了49J,此回火温度下实验钢具有最佳的强韧性配合.回火后低碳贝氏体高强度钢韧性改善主要是由于粗大M/A岛的分解,细小弥散分布的M/A岛可有效阻止裂纹扩展,改善低温冲击韧性.     

风车草泡板型浮岛在污染河水中的脱氮试验

介绍了泡板型浮岛在污染河水中的脱氮试验.实验表明浮岛植物的脱氮效能依次为:风车草>香根草>菖蒲.研究了去除负荷与覆盖率及进水负荷之间关系,结果表明以30%覆盖率为分界点,去除负荷与覆盖率之间的关系有明显的变化;去除负荷与进水负荷之间满足二次函数关系.最后得出了实验条件下的最适宜的覆盖率和进水负荷.