Effect of different feeds on growth, survival and production of African catfish (Clarias gariepinus Burchell)

An experiment was conducted to study the effect of different feeds on growth survival and production of African catfish (C. gariepinus) in six cemented tanks (3m² each) over a period of 120 days. Three different feeds namely Feed A (Saudi-Bangla fish feed, 33.43% protein), Feed B (formulated feed, 40.12% protein) and Feed C (chicken raw intestine, 59.58% protein) were applied to treatments I, II and III respectively. Each of the tanks was stocked with 24 fry with mean initial body weight of 2.56±0.06 g. Feeds were supplied to the fish ad-libitum daily in two instalments. Significantly highest weight gain was obtained in treatment III, however, survival rate was low compared to other treatments. The feed conversion ratio (FCR) values ranged from 2.52-6.4. Survival rate of fish varied between 83 and 96%. Treatment II yielded the highest (5000 kg/ha/120 days) production with the highest survival rate of fish. On the basis of survival rate and production, it is suggested that the formulated feed (Feed B) is suitable for the culture of C. gariepinus in cemented tanks.

Utilisation of vegetable leaves for carp production

The results of two sets of experiments on mono-culture of grass carp (Ctenopharyngodon idella) and mixed culture of carps (grass carp 50 : catla 20 : rohu 15 : mrigal 15) fed exclusively with vegetable leaves are reported. The experiments were conducted with two replicates each in 0.02 ha ponds of Wastewater Aquaculture Division of the Central Institute of Freshwater Aquaculture, Rahara during 1991-93. Monoculture of grass carp stocked at 1000/ha demonstrated an average net production of 21.0 kg/ 0.02 ha/8 months (1501 kg/ha/yr). Mixed culture of carps stocked at 5000 /ha recorded an average net production of 22.5 kg/0.02 ha/8 months (1903.7 kg/ha/yr). Field studies revealed that water bind weed (Ipomoea aquatica) is the most preferred feed of grass carp amongst vegetable leaves followed by amaranths (Amaranthus gangeticus and Amaranthus viridis), cauliflower (Brassica oleracia var. votrytis) and cabbage (Brassica oleracia var. capitata) leaves. Through selection of highly productive leaf vegetables and suitable crop planning on fallow fish pond dykes, round the year feeding programme of grass carp has been explored. Recycling of sewage effluent for vegetable production and utilisation of vegetable leaves for fish production is considered an ideal way of integrated resource management for low cost production.

Sulfide binding characteristics of blood serum in Calyptogena pacifica and Vesicomya gigas

The sulfide binding characteristics of blood serum were studied in vitro in two deep-sea vesicomyid clams, Calyptogena pacifica and Vesicomya gigas. Both the C. pacifica and the V. gigas serum concentrated sulfide at least an order of magnitude above ambient levels. V. gigas accumulated sulfide faster than C. pacifica, reaching saturation at 5000 M after an hour. C. pacifica bound sulfide at half the rate of V. gigas, reaching saturation in about two hours at a substantially higher concentration of sulfide. The observed distribution of the animals near cold seeps in the Monterey Submarine Canyon can be explained by their different sulfide binding abilities. The hypothesis that cold seeps are actually much more unstable sources of sulfide than previously assumed is explored.

Effect of Lates calcarifer seed stocking on the survival and production of Indian major carps reared in a freshwater coastal pond in Konkan region

The experiment indicated feasibility of culturing Indian major carps seed with Lates calcarifer, if the size of Indian major carps is larger. In the present investigation the average growths of Catla catla, Labeo rohita and Cirrhinus mrigala are recorded as 1193, 1120 and 821 g, respectively, during the year 1997-98, 1998-99 and 1999-2000 in 7.5 months. Complete harvesting of L. calcarifer is essential before stocking of new seed. The average growth of L. calcarifer was recorded as about 670 g during the above period. About 5000 numbers of Indian major carps fry per hectare can be stocked under the present culture system

Polyculture of giant freshwater prawn, Macrobrachium rosenbergii, with Indian major carps: a case study

A study conducted in a 450 m² earthen pond to evaluate the production potential of giant freshwater prawn (stocked at 20,000 juveniles/ha) and Indian major carps, catla and rohu (stocked at 5000 juveniles/ha in 2:1 proportion) revealed that in nine months growing period, catla and rohu attained average sizes of 357 and 746 g, respectively, while prawn weighed 48.32 g. The growth of rohu was much faster than catla as indicated by higher relative and absolute weight gains. The total fish production per hectare was estimated to be 2418 kg and prawn production stood at 780 kg with excellent survival of both the fish (>98%) and prawn (>80%).

Influence of stocking density on the culture potential of freshwater catfish Pangasius pangasius in pond

Influence of stocking density on the production of freshwater catfish Pangasius pangasius with formulated feed in ponds was studied. The fish fry were collected from the Meghna river near Chandpur which is a natural breeding ground of this fish. Three stocking densities chosen during this experiment were 5000, 8000 and 11000 fry/ha with an initial weight of 42.57 ±2.51 g. The formulated feed was prepared in the laboratory which contained 45% fish meal, 30% mustard oil cake, 15% wheat bran and 10% rice bran to supply 40.48% protein in feed. The growth of P. pangasius in terms of net weight gain was 409.49, 266.49 and 236.37 g at the 5000/ha, 8000/ha and 11000/ha stocking densities respectively, which was statistically significant (p<0.05). High food conversion ratio (FCR) was also observed during this research study which ranged between 7.06 to 7.72. A production of 2.6 tons/ha at the stocking density of 11000/ha; 2.13 tons/ha at the stocking density of 8000/ha and 2.04 tons/ha at the stocking density of 5000/ha was obtained, while the growth of individual fish at the end of experiment was in opposite order. The result of this experiment indicates that stocking density has significant influence on the culture potential of freshwater catfish P.pangasius.

Ultrafast switching liquid crystals for electro-optic transmissive and reflective displays and microscopic lasers

We have used novel liquid crystals with extremely large flexoelectric coefficients in a range of ultra-fast photonic/display modes, namely 1) the uniform lying helix, that leads to in-plain switching, birefringence based displays with 100 μs switching times at low fields, i.e.2-5 V/μm, wide viewing angle and analogue or grey scale capability, 2) the uniform standing helix, using planar surface alignment and in-plane fields, with sub ms response times and optical contrasts in excess of 5000:1 with a perfect black "off state", 3) the wide temperature range blue phase that leads to field controlled reflective color and 4) high slope efficiency, wide wavelength range tunable narrow linewidth microscopic liquid crystal lasers.

Phantom mutation hotspots in human mitochondrial DNA

Phantom mutations are systematic artifacts generated in the course of the sequencing process. Contra common belief these artificial mutations are nearly ubiquitous in sequencing results, albeit at frequencies that may vary dramatically. The amount of artifacts depends not only on the sort of automated sequencer and sequencing chemistry employed, but also on other lab-specific factors. An experimental study executed on four samples under various combinations of sequencing conditions revealed a number of phantom mutations occurring at the same sites of mitochondrial DNA (mtDNA) repeatedly. To confirm these and identify further hotspots for artifacts, > 5000 mtDNA electropherograms were screened for artificial patterns. Further, > 30000 published hypervariable segment 1 sequences were compared at potential hotspots for phantom mutations, especially for variation at positions 16085 and 16197. Resequencing of several samples confirmed the artificial nature of these and other polymorphisms in the original publications. Single-strand sequencing, as typically executed in medical and anthropological studies, is thus highly vulnerable to this kind of artifacts. In particular, phantom mutation hotspots could easily lead to misidentification of somatic mutations and to misinterpretations in all kinds of clinical mtDNA studies.

Pharmacokinetics of sifuvirtide, a novel anti-HIV-1 peptide, in monkeys and its inhibitory concentration in vitro

Aim: To study the pharmacokinetics of sifuvirtide, a novel anti-human immunodeficiency virus (HIV) peptide, in monkeys and to compare the inhibitory concentrations of sifuvirtide and enfuvirtide on HIV-1-infected-cell fusion. Methods: Monkeys received 1.2 mg/kg iv or sc of sifuvirtide. An on-line solid-phase extraction procedure combined with liquid chromatography tandem mass spectrometry (SPELC/MS/MS) was established and applied to determine the concentration of sifuvirtide in monkey plasma. A four-I-127 iodinated peptide was used as an internal standard. Fifty percent inhibitory concentration (IC50) of sifuvirtide on cell fusion was determined by co-cultivation assay. Results: The assay was validated with good precision and accuracy. The calibration curve for sifuvirtide in plasma was linear over a range of 4.88-5000 mu g/L, with correlation coefficients above 0.9923. After iv or sc administration, the observed peak concentrations of sifuvirtide were 10626 +/- 2886 mu g/L and 528 +/- 191 mu g/L, and the terminal elimination half-lives (T,12) were 6.3 +/- 0.9 h and 5.5 +/- 1.0 h, respectively. After sc, T-max was 0.25-2 h, and the absolute bioavailability was 49% +/- 13%. Sifuvirtide inhibited the syncytium formation between HIV-1 chronically infected cells and uninfected cells with an IC50 of 0.33 mu g/L. Conclusion: An on-line SPE-LC/MS/MS approach was established for peptide pharmacokinetic studies. Sifuvirtide was rapidly absorbed subcutaneously into the blood circulation. The T-1/2 of sifuvirtide was remarkably longer than that of its analog, enfuvirtide, reported in healthy monkeys and it conferred a long-term plasma concentration level which was higher than its IC50 in vitro.

Pond culture of mud crab (Scylla serrata): an economic analysis

The findings are presented of a study conducted to determine the economic feasibility of the pond culture of mud crab (Scylla serrata) at various stocking densities. Investments, costs, and returns are given for a 1 ha crab monoculture at 4 stocking densities - 5000, 10,000, 15,000 and 20,000. Results show that mud crab monoculture in brackishwater ponds is economically feasible at stocking densities of 5000/ha and 10,000/ha.

Zinc oxide nanowire based hydrogen sensor on SOI CMOS platform

Here we report on the successful low-temperature growth of zinc oxide nanowires (ZnONWs) on silicon-on-insulator (SOI) CMOS micro-hotplates and their response, at different operating temperatures, to hydrogen in air. The SOI micro-hotplates were fabricated in a commercial CMOS foundry followed by a deep reactive ion etch (DRIE) in a MEMS foundry to form ultra-low power membranes. The micro-hotplates comprise p+ silicon micro-heaters and interdigitated metal electrodes (measuring the change in resistance of the gas sensitive nanomaterial). The ZnONWs were grown as a post-CMOS process onto the hotplates using a CMOS friendly hydrothermal method. The ZnONWs showed a good response to 500 to 5000 ppm of hydrogen in air. We believe that the integration of ZnONWs with a MEMS platform results in a low power, low cost, hydrogen sensor that would be suitable for handheld battery-operated gas sensors. © 2011 Published by Elsevier Ltd.

Ultrafast switching liquid crystals for electro-optic transmissive and reflective displays and microscopic lasers

We report on novel liquid crystals with extremely large flexoelectric coefficients in a range of ultra-fast photonic modes, namely 1) the uniform lying helix, that leads to in-plain switching, birefringence phase devices with 100 μs switching times at low fields, i.e.2-5 V/μm, and analogue or grey scale capability, 2) the uniform standing helix, using planar surface alignment and in-plane fields, with sub ms response times and optical contrasts in excess of 5000:1 with a perfect optically isotropic or black "off state", 3) the wide temperature range blue phase that leads to field controlled reflective color, 4) chiral nematic optical reflectors electric field tunable over a wide wavelength range and 5) high slope efficiency, wide wavelength range tunable narrow linewidth microscopic liquid crystal lasers. © 2011 Materials Research Society.

大型通江湖泊洞庭湖的鱼类物种多样性及其时空变化

为了解通江湖泊鱼类物种多样性现状,于2004年3月-2004年12月和2005年5月对洞庭湖城陵矶、岳阳和沅江三个区域的鱼类进行逐月调查.共鉴定鱼类69种,隶属6目14科44属,其中59.4%为鲤科鱼类.以种类数和多样性指数分析了群落多样性特征,结果表明洞庭湖鱼类种类多样性较高,且时空变化较大.一般地,湖区与长江干流的距离越近,种类数达到峰值的时间就越早;鱼类多样性在春夏季高于秋冬季,在南洞庭湖高于其它两个区域.以优势度>5000为标准,全湖有17种优势种,其中80.0%为湖泊定居性鱼类.在生态类群方面,

稀有■鲫亚慢性毒性试验

研究了一种快速评价有毒化学品对稀有鲫慢性毒性的试验方法。选择＜3d龄的稀有峋鲫幼鱼开始暴露，试验药物为国际标准参比毒物CU(+2)，Cr(+6)，Zn(+2)和PCP；试验温度为25±1℃，每天更换试验液一次，试验持续5d。以现存量为测试指标，Cu(+2)，Cr(+6)，Zn(+2)和PCP对稀有鲫的无可观察效应浓度[NOEC]为20，2500，100，40ug／L;最低可观察效应浓度[LOEC]为40，5000，200，80ug／L，与7d亚慢性毒性试验结果相接近。试验结果表明，稀有鲫亚慢性毒性试验可从