Factor intensity and economic returns of alternate shrimp crop and shrimp-salt farming in the coastal areas of Bangladesh

The paper examines the factor intensity and economic returns of alternate shrimp-crop and shrimp-salt farming in the coastal areas of Bangladesh. Data were collected from 30 shrimp-crop and 30 shrimp-salt farmers, 30 shrimp farmers and 30 rice farmers from three selected coastal districts of Bangladesh. Cobb-Douglas production function model was used to determine the effect of various factors on alternate shrimp-crop farming. The chosen variables were stocking of juveniles, paddy seed, labour, fertilizers, feed and farm size of respective type of farming. The results indicated that the production function exhibited increasing remrns to scale for alternate shrimp-rice, alternate shrimp-salt and year round shrimp farming while it indicated decreasing returns for year round rice farming. Economic analysis of same system of farming indicated that higher amount of input use produced higher level of yield, gross return and net return for each type of production system.

Dynamics of in-plane arch rocking: An energy approach

This study employs an analytical model to describe the rocking response of a masonry arch to in-plane seismic loading. Through evaluation of the rate of energy input to the system, the model reveals the ground motions that cause maximum rocking amplification. An experimental investigation of small-scale masonry arches subjected to past earthquake time histories is used to evaluate the analytical model and to explore arch rocking behaviour. The results demonstrate that rocking amplification can occur, but is highly sensitive to slight variations in the ground motion. Thus, the accuracy to which the arch response can be predicted is brought into perspective. The concept that the primary impulse of an expected ground motion is fundamentally important in predicting arch collapse is evaluated in light of the developed energy approach. Finally, a statistical method is proposed for predicting the probability of arch collapse during seismic loading.

Morphometric characteristics and meristic traits of Tilapia zillii from three major dams of a southwestern state, Nigeria

Tilapia zillii was examined in three major dams in Ekiti State, Nigeria (Ureje dam, Ado, Egbe dam and Ero dam) for their morphometric characteristics and meristic traits. The results showed that the average body weight of the fish sampled were 145.86±50.06g in Ado, 30.19±9.35g in Egbe and 40.58±52.30g in Ero dam. Average total lengths were 21.29±3.20cm, 12.32±1.74cm and 11.24±1.56cm for Ado, Egbe and Ero dam respectively. The relationship between average weight and length of T. zillii showed that Y=15.202X-179.33 (R2=0.7181), Y=4.40049±-24.075 (R2=0.6708) and Y=2.6676X10.596 (R2=0.0063) for Ado, Egbe and Ero dam respectively. The results on headlength, total length, body weight and standard length and pre-pelvic distance are significantly different at 95% among the T.zillii of the three dams. There was no significant difference in the meristic traits of the T. zillii of the three dams. The population size of T.zillii in the three dams was just too small compared to other species of fish hence the need to assess the stock of fish in these dams critically for the encouragement of proper fishing activities in these dams.

中华眼镜蛇膜毒素与McAb偶联物对白血病细胞的杀伤作用

用中华眼镜蛇膜毒素(CT)与抗人T细胞McAb Wu71偶联制备免疫毒素Wu71CT。经SDS-聚丙烯酰胺凝胶电泳、免疫双扩散和间接免疫荧光检测, 证实结合物中Ab和CT均保持活性。实验表明Wu71:CT有较好的特异性杀伤作用。扫描电镜显示, 免疫毒素作用下的CEM靶细胞膜破列、 萎缩、崩溃, 而非靶细胞大部分保持完整。 图4参12

Adoption, productivity and profitability of rice-fish and fingerling culture in three selected districts of Bangladesh

The study aimed to investigate the productivity and profitability of rice-fish farming. It also determined the factors affecting rice-fish and fingerling production in Bangladesh. Among the total respondents about 55% were involved in rice-fish farming, 37% in pond fish culture and rest 9% in fish nursery. Integrated rice-fish farming contributed about 83% of the annual farm income in Comilla while it was about 20% in both Kishoregonj and Chandpur districts. Among the different farming systems integrated rice-fish culture and rearing fingerlings in the nursery pond were more profitable at the farm level. Farmers earned a net return of Tk. 49,714/ha from integrated fish culture with boro rice while the net return of boro rice-alone was only Tk. 11,179/ha. This indicated that farmer could earn 218% higher net return from integrated rice-fish farming than that of boro rice only farming. Moreover, integrated rice-fish culture also reduced pesticides cost to about 77% and weeding cost to about 51% in boro season. Fingerling nursing earned highest net returns among the three technologies.

On the comparative fishing experiments with a four-seam and a two-seam trawls on the east coast

Fishing experiments were undertaken to study the relative utility of a newly designed four seam type net on a conventional two seam net at the centre along the East Coast in both inshore and deeper zones (up to 100m.) and the results indicated that the new four seam net has given higher catch rate of 6 to 8% more with higher catch rate of fish supposed to belong to off bottom region. Further this gear found more selective in obtaining Lactarius, which is one of the good variety of fish from trawlers, in both quantity as well as in quality. In terms of horizontal spread this new net gave less on comparison with the conventional two seam net, thereby showed corresponding increase in vertical spread; but warp tension remained more or less same in both the gear. Both gear have worked equally well in majority of depth ranges experimented with optimum spread. Finally the results indicated that the new net can work well from the present trawlers along the coast.

细胞色素分子疏水性与进化的关系

在先前研究结果的基础上, 通过对细胞色素分子一维结构间疏水相似性的计算, 建立了相应的分子系统树, 并对细胞色素分子间的进化关系进行了探讨。结果表明, 从蛋白质分子的疏水相似性和非线性三维结构来研究分子间的进化关系, 不仅得到了与用其它方法所得到的结果基本一致的结论, 而且还在一定程度上克服了其它一些方法的局限性, 取得了较佳的结果。

Anti-HIV-1 activity of trichobitacin, a novel ribosome-inactivating protein

AIM: To determine whether trichobitacin, a novel ribosome-inactivating protein purified from the root tubers of Trichosanthes kirilowii, possesses the anti-HIV activity. METHODS: The inhibition of syncytial cell formation induced by human immunodeficiency virus type 1 (HIV-1),was determined under microscope, reduction of HIV-1 p24 antigen expression level was measured by ELISA, and decrease in numbers of HIV-1 antigen positive cells in acutely and-chronically infected cultures were detected by indirect immunofluorescence assay. RESULTS: Trichobitacin Was-found to greatly suppress syncytial cell formation induced by HIV-1 and to markedly reduce both expression of HIV-1 p24 antigen and the number of HIV antigen positive cells in acutely but not chronically HIV-1 infected culture. The median inhibitory concentration (IC50) in inhibition of syncytial cell formation and HIV antigen positive cells were 5 mu g.L-1 (95 % confidence limits: 1.3 - 20 mu g.L-1) and 0.09 mg.L-1 (95 % confidence limits: 0.011 - 0.755 mg.L-1), respectively. CONCLUSION: Trichobitacin is a novel ribosome-inactivating protein with anti-HIV-l activity.

De novo origination of a new protein-coding gene in Saccharomyces cerevisiae

Origination of new genes is an important mechanism generating genetic novelties during the evolution of an organism. Processes of creating new genes using preexisting genes as the raw materials are well characterized, such as exon shuffling, gene duplicat

Effects of stocking density on growth and survival of Mystus gulio in nursery ponds

A study on the effect of stocking density on growth and survival of nona tengra (Mystus gulio) was carried out in brackishwater earthen nursery ponds (2 decimal each) for a period of 42 days. Five-day old captive bred tengra post-larvae (ABL: 4.53±0.83 mm and ABW:3.33 mg) were stocked at four different densities of 200/m² (Treatment-1), 250/m² (Treatment-2), 350/m² (Treatment-3) and 450/m² (Treatment-4). Fries were fed twice a day with a mixture of fine rice bran, mustard oil cake and fishmeal at the ratio of 2:1:1. The specific growth rate (SGR) of larvae did not vary significantly (p>0.05) between T1 (5.096% mg/day) and T2 (5.08% mg/day), but it was found significantly (p<0.05) higher from T3 (4.98% mg/day) and T4 (4.91% mg/day), respectively. The final survival rates of 89.25±5.41% in T1 and 88.72±6.09% in T2 were found similar (p>0.05), but significantly higher (p<0.05) than those of, 76.20±4.77% in T3 and 70.34±5.71% in T4. The results indicate that 5-day old hatchery bred nona tengra post-larvae can be nursed in earthen pond at a stocking density of 200-250/m².

Species diversification in coastal aquaculture: production potentials of shrimp (Penaeus monodon) with mono and mixed sex tilapia

An experiment of 120 days of culture was conducted in brackishwater earthen ponds having an area of 0.2ha each. The hatchery produced shrimp (Penaeus monodon) post larvae were stocked in the 40m² fine meshed nylon net nursery enclosures were fed with commercial pellet feed. After two weeks of nursing, juveniles were allowed to spread in cultural pond by opening the fence. Fingerlings of three different strain of tilapia were stocked as shrimp and Strain-1 all male (monosex) (T1), shrimp and Strain-2 all male (T2), shrimp and Strain-3 mixed sex population (T3) @ 20.000/ha and 10.000/ha, respectively and shrimp only (monoculture) (T4) @ 20.000/ha. The shrimp and fish were fed with farm made feed consisting of a mixture of fishmeal 29%, MOC 15%, rice bran 30%, soybean meal 16%, wheat flour 9% and vitamin premix 0.1%. The average final weight of shrimp was 24.9±1.13g, 23.41±3.26g and 26.67±1.89g that stocked with tilapia in treatments T1, T2, and T3 respectively. The final average weight of shrimp in monoculture (T4) was 27.41±0.76g, apparently higher but insignificant in treatments. The survival of shrimp was 42.17%, 32.38%, 39.45% and 61.98% in treatments T1 T2, T3 and T4 respectively. The production of shrimp in concurrent culture was 193.67, 154.26 and 210.41kg/ha in T1, T2 and T3, respectively, while in monoculture (T4) was 339.77 kg/ha. The growth and survival of tilapia among the treatments was insignificant. The growth of monosex tilapia ranged 225.29 and 291.31g and survival 62.77 and 72.20% in T1 and T2, respectively, in mixed sex was 193.0g and 83.20% (T3). The production of tilapia monosex strains was 1676.69kg/ha (Strain-2 all male) and 1668.98 kg/ha (Strain-1 all male) while that of Strain-3 mixed sex population was 1622.92 kg/ha.