Electrophoretic and meristlc separation of blue maomao and sweep P. J. Smith,B. A. Wood,and P. G. Benson

Fourteen proteins and 12 morphometric characters were examined in specimens of blue maomao and sweep to resolve the question: Are they one or two species? Specimens were fixed for the same alleles at 12 protein loci and shared alleles at 4 polymorphic loci. At a further polymorphic locus they differed in allele frequency and at three loci they did not share alleles. A genetic distance of 0.209 was found between blue maomao and sweep suggesting that they diverged about 1 million years ago. One meristic character showed a difference between specimens.

On the basis of the electrophoretic data and on gill raker counts it is considered that blue maomao and sweep are two separate species. In view of reported differences from Australian specimens the allocation of scientific names at least to sweep remains uncertain.     

Morphological observation and rbcL gene sequences studies of two new species, Grateloupia dalianensis H.W.Wang et D.Zhao, sp. nov. and G. yinggehaiensis H.W.Wang et R.X.Luan, sp. nov. (Halymeniaceae, Rhodophyta) from China

A few species in the genus Grateloupia (Halymeniaceae,Rhodophyta) have been investigated in detail with respect to morphological observations and molecular analyses.In this study,the authors document the vegetative and reproductive structures of two new species of Grateloupia,G.dalianensis H.W.Wang et D.Zhao,sp.nov.and G.yinggehaiensis H.W.Wang et R.X.Luan,sp.nov.They both have the morphological character that carpogonial ampullae and auxiliary cell ampullae are the simple Grateloupia-type.The two species can be distinguished from other species of the genus by their distinctive morphological features respectively.Based on ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) gene sequences,the phylogenetic tree obtained in the study indicated that they are both embedded within the Grateloupia clade.G.dalianensis clusters a subclade with G.asiatica,and G.yinggehaiensis forms a single monophyletic subclade with G.hawaiiana.     

Oceanic crustal basement: A comparison of seismic properties of D.S.D.P. basalts and consolidated sediments

Compressional (V_P) and shear (V_s) wave velocities have been measured to 1.0 kbar for 14 cores of well-consolidated sedimentary rock from Atlantic and Pacific sites of the Deep Sea Drilling Project. The range of V_P (2.05–5.38 km/sec at 0.5 kbar) shows significant overlap with the range of oceanic layer-2 seismic velocities determined by marine refraction surveys, suggesting that sedimentary rocks may, in some regions, constitute the upper portion of layer 2. Differing linear relationships between V_P and V_s for basalts and sedimentary rocks, however, may provide a method of resolving layer-2 composition. This is illustra ted for a refraction survey site on the flank of the Mid-Atlantic Ridge where layer-2 velocities agree with basalt, and two sites on the Saya de Malha Bank in the Indian Ocean where layer-2 velocities appear to represent sedimentary rock.     

美国无人潜航器反制措施研究现状

简要分析了无人潜航器反制措施的必要性,从探测分类、软杀伤对抗和硬杀伤对抗 3 个方面总结分析了美国无人潜航器反制措施研究现状。美国无人潜航器探测目前主要依靠反蛙人探测系统,但是反蛙人探测系统存在告警距离短、响应时间不足的问题。因此,美国海军寻求利用海洋哺乳动物和海洋生物探测和分类潜航器的方法。软杀伤对抗主要包括 UUV 捕获、欺骗、干扰及网络对抗;硬杀伤对抗主要介绍了通过超空泡子弹破坏、摧毁 UUV。