Preliminary observations on the effect of electrical seine on fish catch

Forty-six experiments were done with the electric seine in 24 tanks with a.c. and interrupted a.c. The source of electrical energy was a 3 Kw a.c. generator of water-cooled diesel engine. A control seining without applying electricity was conducted for every experiment with electric "seine" to have a comparison for the efficiency of electric "seine" over control ones. Electric seine was found to have an increased catch over control seining both in numbers and in weight. Electric seine with two electrodes was found to have better effect over three electrodes. Benthic fishes like Cirrhina mrigala, Notopterus notopterus, Cyprinus carpio, Glassogobius giuris, Ophicephalus sp. and Mystus sp. were found to be more sensitive in electric "seine". Increased catch of small fishes like C. mrigala, N, notopterus and Ophicephalus sp. has been observed in electrical "seine" in addition to larger ones.

Unsteady transition in an axial-flow turbine. Part 1. Measurements on the turbine rotor

Previously published measurements in a low-speed, single-stage, axial-flow turbine have been reanalyzed in the light of more recent understanding. The measurements include time-resolved hot-wire traverses and surface hot film gage measurements at the midspan of the rotor suction surface with three different rotor-stator spacings. This paper investigates the suction surface boundary layer transition process, using surface-distance time plots and boundary layer cross sections to demonstrate the unsteady and two-dimensional nature of the process.

Pescaria de camarāo e gestāo: alguns exemplos de experiências de outras áreas

In volume 60 of the FAO Statistical Yearbook of Fisheries, we can see that the world shrimp catch in 1985 was 1.9 million tons. This represents an increase, since 1980, of 250 tons (15%). Catches of shrimp is about 2.5% of global marine fishery products. But as we know, its economic value in the global market is much higher, reaching a value of 30%.

Ground improvement methods for liquefaction remediation

Soil liquefaction continues to be a major source of damage to buildings and infrastructure after major earthquake events. Ground improvement methods are widely used at many sites worldwide as a way of mitigating liquefaction damage. The relative success of these ground improvement methods in preventing damage after a liquefaction event and the mechanisms by which they can mitigate liquefaction continue to be areas of active research. In this paper the emphasis is on the use of dynamic centrifuge modelling as a tool to investigate the effectiveness of ground improvement methods in mitigating liquefaction risk. Three different ground improvement methods will be considered. First, the effectiveness of in situ densification as a liquefaction resistance measure will be investigated. It will be shown that the mechanism by which soil densification offers mitigation of the liquefaction risk can be studied at a fundamental level using dynamic centrifuge modelling. Second, the use of drains to relieve excess pore pressures generated during an earthquake event will be considered. It will be shown that current design methods can be further improved by incorporating the understanding obtained from dynamic centrifuge tests. Finally, the use of soil grouting to mitigate liquefaction risk will be investigated. It will be shown that by grouting the foundation soil, the settlement of a building can be reduced following earthquake loading. However, the grouting depth must extend the whole depth of the liquefiable layer to achieve this reduction in settlements.

Illegal fishing of inland water bodies of Nigeria: Kainji experience

It is a common knowledge that illegal fishing which includes use of wrong gears, explosives, excessive exploitation of choice stocks, enhancement and stocking of water body and pollution has devastating effects on the critical biomass of fish biodiversity and livelihood activities associated with fishing. Efforts worldwide to arrest these menace are significant because it has been found that illegal fishing has made fishing non sustainable, resulted in poor fishermen catches, and exacerbated the use of illegal gears in an effort to a must catch. Conflict between fisher folk and policies has continued to generate different strategies in the control of illegal fishing. Some of these strategies at regional and National levels include creation and implementation of fisheries laws, fishing edicts, code of conduct for responsible fisheries, policing of inland water bodies, capacity building and capability through training of fishermen, creating necessary awareness, arrest and punishment of offenders. There are also other initiative on conservation and management of freshwater ecosystems which have interrelation with illegal fishing. This paper examines efforts in promoting and boosting the fisheries of Lake Kainji, through creating necessary awareness, campaign visits, radio programmes, gear control, reward systems, integration and diversification of livelihood activities, community based management and policing. It further analyses what is working, problems, and prospect of fisheries laws, the need to integrate factors of political policies, other global initiative on water management for people and nature. Recommendations on strategies including protection of fishing grounds, establishment of catch data base, integration of other intervention as alternative source of income to enhance livelihood, reduce fishing pressure, and capacity building of fisher folks, development of rules and regulations that is community based are highlighted.

脱抗原牛角胎骨移植家兔后的特异性免疫反应

目的 研究脱抗原水牛角胎移植后的免疫排斥反应和成骨效应。方法 以日本大耳白兔为动物模型，分别植入经30% H_2O_2、0.6 mol/L HCl脱抗原脱钙，30% H_2O_2脱抗原不脱钙2种温和方法处理的水牛角胎至兔左侧肢骨缺损处。体外检测外周血特异性T淋巴细胞转化率和ELISA检测血清特异性抗角胎IgG抗体。结果 脱抗原脱钙处理显著地降低了角胎的抗原性，与对照相比，未见受体对移植物产生显著的特异性细胞和体液免疫反应（P > 0.05），尤其是脱抗原不脱钙角胎效果更佳。两者成骨效果均良好。结论 脱抗原角胎是一种免疫原性低、成骨效果好、来源方便的骨移植材料。

Smoking of shrimp and fish from coastal village of north-west Bangladesh

Traditional smoking of mixed shrimp species is a method of preservation in coastal region of Bangladesh. Besides traditional smoked shrimp, attempt had been made to produce smoked shrimp from brown shrimp, Metapenaeus monoceros and fish from mugil, Liza parsia and the quality of smoked product was found good very on the basis of physical properties, proximate composition and mineral contents of the products.

Dissecting the matrilineal components of Tongjiang cattle from Southwest China

Tongjiang cattle are a local cattle population of Sichuan Province, China, numbering approximately half a million in 2005. They have long been grouped into the Bashan breed, although they have a unique breeding history and phenotypic characteristics, as w

芒果炭疽病[Colletotrichum gloeosporioides (Penz)]生物学及其综合防治研究

在云南景谷芒果种植区, 芒果炭疽病对芒果树嫩叶、嫩梢、花穗和果实为害率分别为85.7％、63.4％、77.1％和73.3％。风雨和昆虫媒介是传播的主要方式。发生为害最适温度为22℃--25℃, 相对湿度为85％--100％。该病在景谷种植区全年均可发生为害, 主要为害在发生期。发生前期为害, 是花穗干瘪和幼果掉落的原因之一。采取综合防治措施, 特别在发生前期适时防治, 可控制发生为害。

摘除小鼠颌下腺其附睾内精子数的变化

14周龄雄性昆明种小白鼠颌下腺摘除后第4周开始,附睾内精子数量呈显著减少趋势,第5和第6周的精子数分别为0.56±0.26×10~(7)和0.50±0.13×10~(7),与对照相比分别有显著差异( P<0.05)和非常显著差异( P<0.01)。摘除颌下腺手术后5周内小鼠的体重与对照相比无显著变化,但第6周的体重下降有明显的统计学差异( P<0.01)。

Stress within the postseizure time window inhibits seizure recurrence

Recurrence is a key characteristic in the development of epilepsy. It remains unclear whether seizure recurrence is sensitive to postseizure stress. Here, tonic-clonic seizures were induced with a convulsive dose of pentylenetetrazole (PTZ), and acute seizure recurrence was evoked with a subconvulsive dose of the drug. We found that stress inhibited seizure recurrence when applied 30 minutes or 2 hours, but not 4 hours, after the tonic-clonic seizure. The time-dependent anti-recurrence effect of stress was mimicked by the stress hormone corticosterone and blocked by co-administration of mineralocorticoid and glucocorticoid receptor antagonists. Furthermore, in a PTZ-induced epileptic kindling model, corticosterone administered 30 minutes after each seizure decreased the extent of seizures both during the kindling establishment and in the following challenge test. These results provide novel insights into both the mechanisms of and therapeutic strategies for epilepsy. (C) 2010 Elsevier Inc. All rights reserved.