Stock assessment and biology of Johnius glaucus (Day) off the northwest coast of India

The stock size and biology of Johnius glaucus (Day) resource off the northwest coast of India were studied for 1982-83 and 1983-84. The total length at the end of 6, 12, 18, 24 and 26 months was 121 mm, 183 mm, 237 mm, 261 mm and 264 mm respectively. The length growth parameters were: L∞=300 mm, K=0.0807 (monthly) and t(sub)0=-0.51 month. The weight growth parameters were: W∞= 317g, K=0.0762 (monthly) and t(sub)0= -0.41 month. The exploited stock mainly composed of 1/2 + and 1+ age groups. The annual Z, M and F were 2.34, 1.49 and 0.85 respectively. The l(sub)b, t(sub)b, l(sub)r, t(sub)r and selection factor K were 155 mm, 0.75 year, 65 mm, 0.25 year and 3.875 respectively. The Yw/R was optimum at the exploitation rate (E) of 0.75 and coded mesh size of 37 mm. The total stock for 1982-83 and 1983-84 was 14,624 and 26,190 tons respectively. The standing stock of 1982-83 and 1983-84 was 5,645 and 10,110 tons respectively. The MSY for 1982-83 and 1983-84 was 6,623 and 11,788 tons respectively. The F and Z were lowest in 0+ age group and highest in 1+ age group.

Applications of stochastic context-free grammars using the Inside-Outside algorithm

This paper describes two applications in speech recognition of the use of stochastic context-free grammars (SCFGs) trained automatically via the Inside-Outside Algorithm. First, SCFGs are used to model VQ encoded speech for isolated word recognition and are compared directly to HMMs used for the same task. It is shown that SCFGs can model this low-level VQ data accurately and that a regular grammar based pre-training algorithm is effective both for reducing training time and obtaining robust solutions. Second, an SCFG is inferred from a transcription of the speech used to train a phoneme-based recognizer in an attempt to model phonotactic constraints. When used as a language model, this SCFG gives improved performance over a comparable regular grammar or bigram. © 1991.

Macrogyrodactylus polypteri Malberg on Polypterus senegalus in the Sudan

Polypterus is a genus of fishes which is best considered as descendent of the Palaeoniscid stock coming from Devonian times (400 million years ago). This genus, one of the indigenous fishes of Africa, is of economic importance in some parts of the Sudan.

Comparison of stabilised/solidified mixes of model drill cuttings based on the North Sea and Red Sea Areas

Following the global stringent legislations regulating the wastes generated from the drilling process of oil exploration and production activities, the management of hazardous drill cuttings has become one of the pressing needs confronting the petroleum industry. Most of the prevalent treatment techniques adopted by oil companies are extremely expensive and/or the treated product has to be landfilled without any potential end-use; thereby rendering these solutions unsustainable. The technique of stabilisation/solidification is being investigated in this research to treat drill cuttings prior to landfilling or for potential re-use in construction products. Two case studies were explored namely North Sea and Red Sea. Given the known difficulties with stabilising/solidifying oils and chlorides, this research made use of model drill cutting mixes based on typical drill cutting from the two case studies, which contained 4.2% and 10.95% average concentrations of hydrocarbons; and 2.03% and 2.13% of chlorides, by weight respectively. A number of different binders, including a range of conventional viz. Portland cement (PC) as well as less-conventional viz. zeolite, or waste binders viz. cement kiln dust (CKD), fly ash and compost were tested to assess their ability to treat the North Sea and Red Sea model drill cuttings. The dry binder content by weight was 10%, 20% and 30%. In addition, raw drill cuttings from one of the North Sea offshore rigs were stabilised/solidified using 30% PC. The characteristics of the final stabilised/solidified product were finally compared to those of thermally treated cuttings. The effectiveness of the treatment using the different binder systems was compared in the light of the aforementioned two contaminants only. A set of physical tests (unconfined compressive strength (UCS)), chemical tests (NRA leachability) and micro-structural examinations (using scanning electron microscopy (SEM), and X-ray diffraction (XRD)) were used to evaluate the relative performance of the different binder mixes in treating the drill cuttings. The results showed that the observed UCS covered a wide range of values indicating various feasible end-use scenarios for the treated cuttings within the construction industry. The teachability results showed the reduction of the model drill cuttings to a stable non-reactive hazardous waste, compliant with the UK acceptance criteria for non-hazardous landfills: (a) by most of the 30% and 20% binders for chloride concentrations, and (b) by the 20% and 30% of compost-PC and CKD-PC binders for the Red Sea cuttings. The 20% and 30% compost-PC and CKD-PC binders successfully reduced the leached oil concentration of the North Sea cuttings to inert levels. Copyright 2007, Society of Petroleum Engineers.

Geometrical properties and turbulent flame speed measurements in stationary premixed V-flames using direct numerical simulation

Three dimensional, fully compressible direct numerical simulations (DNS) of premixed turbulent flames are carried out in a V-flame configuration. The governing equations and the numerical implementation are described in detail, including modifications made to the Navier-Stokes Characteristic Boundary Conditions (NSCBC) to accommodate the steep transverse velocity and composition gradients generated when the flame crosses the boundary. Three cases, at turbulence intensities, u′/sL, of 1, 2, and 6 are considered. The influence of the flame holder on downstream flame properties is assessed through the distributions of the surface-conditioned displacement speed, curvature and tangential strain rates, and compared to data from similarly processed planar flames. The distributions are found to be indistinguishable from planar flames for distances greater than about 17δth downstream of the flame holder, where δth is the laminar flame thermal thickness. Favre mean fields are constructed, and the growth of the mean flame brush is found to be well described by simple Taylor type diffusion. The turbulent flame speed, sT is evaluated from an expression describing the propagation speed of an isosurface of the mean reaction progress variable c̃ in terms of the imbalance between the mean reactive, diffusive, and turbulent fluxes within the flame brush. The results are compared to the consumption speed, sC, calculated from the integral of the mean reaction rate, and to the predictions of a recently developed flame speed model (Kolla et al., Combust Sci Technol 181(3):518-535, 2009). The model predictions are improved in all cases by including the effects of mean molecular diffusion, and the overall agreement is good for the higher turbulence intensity cases once the tangential convective flux of c̃ is taken into account. © 2010 Springer Science+Business Media B.V.

SRY基因进化的研究现状

国家自然科学基金重点项目及中国科学院重大项目资助。

氨基酸和微量元素在虫草菌感染虫草蝠蛾幼虫中的影响

该文收集了虫草蝠蛾2—6龄五个龄期组幼虫, 四组处于不同发育阶段的虫草菌丝体、被虫草菌感染后的僵虫体、全虫草体及子实体共计12组样品的氨基酸, 微量元素分析资料, 应用聚类分析方法对各样品变量的分类单元及其贡献值进行初步探讨. 结果显示: 各样品间的氨基酸、微量元素组成水平各不相同, 5、4龄幼虫的总体组成水平在比例关系上更接近全虫草体, 虫草菌丝体愈培养至晚期就愈接近子实体的组成. 分析认为, 5、4龄虫易被感染与其氨基酸、微量元素的组成背景值有关; 以培养至晚期的菌丝体或有性生殖孢子更易感染幼虫。

Population genetic structure of Rutilus frisii kutum in Caspian Sea using biometry and microsatellite molecular technique

In order to carry out Biometric studies, 75 samples were caught from 3 locations ( Tajan river, Sefidrud and Shirud) using Salic and the length (±1 mm) and weights (± 5 gr) of samples were determined. Using One-way ANOVA by SPPSS software, there wasn’t significant difference between locations in length and fecondity (P ≥0.01(, but there was significant difference between Shirud and tajan samples with sefidrud in weight ) P≤0.01(. In order to carry out genetic variation studies, 210 fish were caught from 3 different regions of the Iranian coastline (Khoshkrud, Tonekabon, Gorganrud) and 1 region in Azerbaijan (Waters of the Caspian Sea close to Kura River mouth) during 2008-2009 . Genomic DNA was extracted of fin using the phenol-chloroform. The quantity and quality of DNA from samples were assessed by spectrophptometer and 1% agarose gel electro-phoresis. PCR was carried out using 15 paired microsatellite primers. PCR products were separated on 8% polyacrylamide gels that were stained using silver nitrate. Molecular weight calculate using UVTech software. The recorded microsatellite genotypes were used as input data for the GENALEX software version 6 package in order to calculate allele and genotype frequencies, observed (Ho) and (He) expected heterozygosities and to test for deviations from Hardy-Weinberg equilibrium. Genetic distance between two populations was estimated from Nei standard genetic distance and genetic similarity index (Nei, 1972). Genetic differentiation between populations was also evaluated by the calculation of pairwise estimates of Fst and Rst values. From 15 SSR markers were used in this investigation, 9 of them were polymorph. Average of expected and observed heterozygosity was 0.54 and 0.49 respectively. Significant deviations from Hardy-Weinberg expectations were observed in all of location except Anzali lagoon- autumn in AF277576 and EF144125, Khoshkrud in EF144125 and Gorganrud and Kura in AF277576. Using Fst and Rst there was significant difference between locations ) P≤0.01(. According to Fst , the highest population differentiation (Fst= 0.217) was between Gorganrud and Khoshkrud that have the lowest Nm and the lowest (Fst= 0.086) was between Gorganrud and Tonekabon that have the highest Nm. Using Rst the highest population differentiation (Rst= 0.271) was between Tonekabon and spring Anzali lagoon and the lowest (Rst= 0.026) was between Tonekabon and Autumn Anzali 159 lagoon. Also the difference between Spring Anzali lagoon and Autumn Anzali lagoon was noticeable (Fst=0.15). AMOVA analysis with consideration of 2 sampling regions (Iran and Azerbaijan) and 7 sampling locations (Iran: Khoshkrud, Tonekabon, Gorganrud, Spring Anzali lagoon and Autumn Anzali lagoon ; Azerbaijan: the Kura mouth) revealed that almost all of the variance in data namely 83% )P≤0.01( was within locations, Genetic variances among locations was 14% )P≤0.01( and among regions was 3% )P≤0.01(. The genetic distance was the highest (0.646) between Gorganrud and Autumn Anzali lagoon populations, whereas the lowest distance (0.237) was between Gorganrud and Tonekabon River. Result obtained from the present study show that at least 2 different population of Rutilus frissi kutum are found in the Caspian sea,which are including the kura river population and the southern Caspian sea samples and it appears that there is more than one population in southern Caspian sea that should be attantioned in artifical reproduction Center and stoke rebilding.

盘鮈属鱼类的分类研究及两新种记述 (鲤形目: 鲤科)

盘鮈属是我国鲤科鱼类的一个特有属, 过去已记录7种, 因早期发表的云南盘鮈原始描述简略, 国内又无人察看过模式标本, 造成一些种名归属混乱. 该工作在核对多数种的模式标本或地模标本的基础上, 对盘鮈属鱼类的分类性状重新估价, 认为多鳞盘鮈 D. polylepis Huang 不能成立, 为长鳔盘鮈 D. macrophysallidos Huang 的同物异名, 予以归并, 经整理本属鱼类可分为8个种, 其中具2个新种, 文中给出了分种检索表, 还就过去分类中存在的其他问题进行了讨论。