Mitochondrial DNA hypervariable region-1 sequence variation and phylogeny of the concolor gibbons, Nomascus

The still little known concolor gibbons are represented by 14 taxa (five species, nine subspecies) distributed parapatrically in China, Myanmar, Vietnam, Laos and Cambodia. To set the stage for a phylogeographic study of the genus we examined DNA sequence

The potential of mixed culture of freshwater giant prawn Macrobrachium rosenbergii de Man and tiger shrimp Penaeus monodon Fab. at Khulna region, Bangladesh

The freshwater giant prawn (golda), Macrobrachium rosenbergii and tiger shrimp (bagda), Penaeus monodon were stocked together with or without fin fishes at different stocking rates in semi-saline waters at Khulna region and their growth, survival, yield and costreturn analysis were made. Survival rate of golda and bagda ranged from 23.0 to 36.8% and 8.2 to 24%, respectively. The both species were significantly affected by their own stocking density. The average final weight of golda and bagda ranged from 62.4 to 73.3 g and 32.0 to 66.4 g. The bivariate analysis of average final weight of both golda and bagda revealed that golda positively and bagda negatively influenced by the total stocking density. However, the results of the individual sizes of both golda and bagda showed an increase in the proportions of smaller animals and a decrease in the proportion of larger ones with increasing stocking rates. The harvesting weights of all animals in the experimental ghers were in marketable sizes although their prices varied with the individual size. The total production comprised of both golda and bagda ranged from 514.6 to 952.8 kg ha·1, over a culture period of 10 months. Return on investment ranged from 51.0 to 125.7%.

Reprint of: Flow filtering and the physical sources of aerodynamic sound

The physical sources of sound are expressed in terms of the non-radiating part of the flow. The non-radiating part of the flow can be obtained from convolution filtering, as we demonstrate numerically by using an axi-symmetric jet satisfying the Navier-Stokes equations. Based on the frequency spectrum of the source, we show that the sound sources exhibit more physical behaviour than sound sources based on acoustic analogies. To validate the sources of sound, one needs to let them radiate within the non-radiating flow field. However, our results suggest that the traditional Euler operator linearized about the time-averaged part of the flow should be sufficient to compute the sound field. © 2010 Published by Elsevier Ltd.

Gene admixture in the Silk Road region of China: Evidence from mtDNA and melanocortin 1 receptor polymorphism

Mitochondrial DNA control region segment I sequences and melanocortin 1 receptor (MC1R) gene polymorphism were examined in ethnic populations in the silk road region of China. Both the frequencies of the MC1R variants and the results of mtDNA data in this region presented intermediate values between those of Europe and East and Southeast Asia, which suggested extensive gene admixture in this area and was in general agreement with previous studies. Phylogenetic analysis of the ethnic populations in the Silk Road region that based on mtDNA data didn't show expected cluster pattern according to their ethnogenesis. We suspect that a high migration rate in female among these closely related populations and other three demographic events might account for it.

CFD-DEM simulation of propagation of sound waves in fluid particles fluidised medium

In this work, speed of sound in 2 phase mixture has been explored using CFD-DEM (Computational Fluid Dynamcis - Discrete Element Modelling). In this method volume averaged Navier Stokes, continuity and energy equations are solved for fluid. Particles are simulated as individual entities; their behaviour is captured by Newton's laws of motion and classical contact mechanics. Particle-fluid interaction is captured using drag laws given in literature.The speed of sound in a medium depends on physical properties. It has been found experimentally that speed of sound drops significantly in 2 phase mixture of fluidised particles because of its increased density relative to gas while maintaining its compressibility. Due to the high rate of heat transfer within 2 phase medium as given in Roy et al. (1990), it has been assumed that the fluidised gas-particle medium is isothermal.The similar phenomenon has been tried to be captured using CFD-DEM numerical simulation. The disturbance is introduced and fundamental frequency in the medium is noted to measure the speed of sound for e.g. organ pipe. It has been found that speed of sound is in agreement with the relationship given in Roy et al. (1990). Their assumption that the system is isothermal also appears to be valid.

Active control of sound radiated by a submarine hull in bending vibration using inertial actuators

Submarines are efficient sources of low frequency radiated noise due to the vibrations induced by the rotation of the propeller in a non uniform wake. In this work the possibility of using inertial actuators to reduce the far field sound pressure is investigated. The submerged vessel is modelled as a cylindrical shell with two conical end caps. Complicating effects such as ring stiffeners, bulkheads and the fluid loading are taken into account. A harmonic radial force is transmitted from the propeller to the hull through the stern end cone and it is tonal at the blade passing frequency (rotational speed of the shaft multiplied by the number of blades). The actuators are attached at the inside of the prow end cone to form a circumferential array. Both Active Vibration Control (AVC) and Active Structural Acoustic Control (ASAC) are analysed and it is shown that the inertial actuators can significantly reduce the far field sound pressure.

A Molecular Phylogeny of Macaca Based on Mitochondrial Control Region Sequences

通过线粒体部分控制区DNA 序列数据探讨7 种猕猴属物种的分子系统发育关系。结果表明熊猴的 核苷酸多样度最高, 而藏酋猴核苷酸多样度较低。基于控制区序列数据所构建的最大似然树, 不考虑食蟹猴的 位置, 7 种猕猴物种可粗略地分为3 个种组, 即狮尾猴组(包括北平顶猴) 、头巾猴组(包括红面猴、熊猴和藏 酋猴) 和食蟹猴组(包括恒河猴和台湾猴) 。与前人( Fooden & Lanyon , 1989 ; Tosi et al , 2003a ; Deinard & Smith , 2001 ; Evans et al , 1999 ; Hayasaka et al , 1996 ; Morales &Melnick , 1998) 的结果不同, 我们的结果支 持食蟹猴比北平顶猴分化早的假设; 东部恒河猴(相对于台湾猴) 和东部熊猴(相对于藏酋猴) 出现并系。与 Y染色体、等位酶、核基因以及部分形态学数据推测的结果(Delson , 1980 ; Fooden &Lanyon , 1989 ; Fooden , 1990 ; Tosi et al , 2000 , 2003a , b ; Deinard & Smith , 2001) 一致, 红面猴应归于头巾猴组, 但此结论与前人 (Hayasaka et al , 1996 ; Morales &Melnick , 1998 ; Tosi et al , 2003a) 依据线粒体得到的结果有较大分歧。

Structural features of geostrophic circulation in open region of the South China Sea

On the basis of observation data of water temperature and salinity the mean seasonal geostrophic circulation in open region of the South China Sea (SCS) was computed by the dynamic method relative to the 800 decibar reference surface. The results of computation let go to following notices: In both main monsoons (winter and summer) there are two main geostrophic eddies: the anticlockwise eddy in the northern and northwestern part, and the clockwise eddy in the southern part of the SCS with corresponding divergent and convergent zones. The main frontal zones go along the middle latitudes of the sea from the southern continental shelf of Vietnam to the area west of Luzon Island. The strength and stability of the current in winter are higher than in summer. The Kuroshio has an enough strong branch intruding into the SCS through Bashi Strait in winter creating in the sea the water structure similar to that of the Northwest Pacific subtropical and tropical regions. In summer the Kuroshio water can intrude directly only into the area southwest of Taiwan.

The free alpha amino acid nitrogen contents of some common food fishes of Kakinada region, Andhra Pradesh

The moisture and free alpha amino nitrogen contents of some important food fishes and shell fishes of Kakinada region have been studied. Crustaceans and molluscs contain free alpha amino acids in quantities several times higher than all other aquatic animals examined in this study. Their probable role in the physiological activities of these animals has been discussed.

The period gene: High conservation of the region coding for Thr-Gly dipeptides in the Drosophila nasuta species subgroup

In this study, the region corresponding to the Thr-Gly region of the period (per) gene in the Drosophila nasuta subgroup of species was sequenced. The results showed, that this region was highly conserved in the D. nasuta subgroup. There were only nine variable sites found in this 300-bp-long region, all located in two small regions highly variable among Drosophila species. No length variation was observed either within this subgroup or in the Yunnan (YN) population of D. albomicans. The deduced amino acid sequences were identical for all 14 taxa in the D. nasuta subgroup, and a stretch of alternating Thr-Gly pairs was not observed in this subgroup. A phylogenetic tree was constructed. The clustering of some species was in general agreement with previous works, but it also raised some question on the phylogenetic relationship between the nasuta species. The data did not implicate the Thr-Gly region playing a role in behavioral isolation in this subgroup of Drosophila.

Length polymorphism of thymidylate synthase regulatory region in Chinese populations and evolution of the novel alleles

The tandemly repeated 28-bp sequence in the 5'-terminal regulatory, region of human thymidylate synthase (TSER), which has been reported to be polymorphic in different populations, was surveyed in 668 Chinese from 9 Han groups, 8 ethnic populations, and 3