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在粗蛋白42%和粗脂肪8%的半精制饵料中,添加不同剂量的鱼油、玉米油、花生油和芝麻油,使20C:5n-3(EPA)+22C:6n-3(DHA)的含量(占总脂肪的%)和n-3/n-6比例分别为14.942,0.728;15.551,0.851;19.365,1.238;19.976,1.345和20.457,1.406。饲喂黄颡鱼(Pelteobagrus fulvidraco,Richardson)幼鱼50 d,研究了不同脂肪酸含量及比例对黄颡鱼幼鱼体组成的影响。结果表明,随着饵料中EPA+DHA的含量和n-3/n-6比例的逐渐增加,鱼体肌肉中水分含量逐渐增加,粗蛋白含量逐渐降低,肌肉中的n-3脂肪酸含量和n-3/n-6比例逐渐增加,肌肉的n-6和n-9脂肪酸含量逐渐降低。 相似文献
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[目的]检测鲤鱼、鲫鱼和鲶鱼3种淡水鱼血浆中游离磷脂的有无,为探索3种淡水鱼凝血现象的生理机制奠定基础。[方法]采用加热兔脑磷脂凝血有效性试验检测加热磷脂的活性。以兔的PPP为基质血浆,用加热的鲤、鲫和鲶CFP为被检测血浆,混合后分别测定凝血时间,并测定其血浆中是否存在参与凝血的游离磷脂。将鲤、鲫和鲶CFP分别80℃加热20min,冷却至室温,再与兔的不同稀释倍数(血浆∶去离子水:1∶0,1∶1,1∶2,1∶3)的PPP混合,然后各混合血浆再加入0.05mol/LCaCl2(2∶1),测混合血浆凝固时间。以3种未加加热鱼的CFP和兔的PPP混合血浆复钙时间作为对照。[结果]各试验动物血浆加热磷脂的APTT平均值与对照间差异不显著(P0.05),说明磷脂在80℃加热20min后,其凝血功能并未发生变化。家兔PPP、加热后的鱼CFP-兔PPP混合血浆、正常鱼CFP-兔PPP混合血浆3个试验组的平均凝固时间,加热鱼CFP-兔PPP混合血浆凝固最慢,正常鱼CFP-兔PPP混合血浆凝固最快,家兔PPP凝固时间居中,不同稀释倍数的血浆复钙时间差异极显著(P0.01)。[结论]鲤鱼、鲫鱼和鲶鱼的CFP中不含游离的磷脂,它们CFP在无磷脂存在的条件下也可以发生凝固。 相似文献
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Seismic Behaviors of Frames in Frame Wall Structures under Rare Earthquakes on the Zone of Fortification Intensity 8 in China 总被引:1,自引:0,他引:1
To investigate the seismic behaviors of frames in frame wall structures (dual system), which may be different from those of frame structures, two frame wall structures were designed conforming to current Chinese design codes. One is a twenty four story building on the Zone of Fortification Intensity 8 (0.3g), and the other is a thirty story building on the Zone of Fortification Intensity 8 (0.2g). Then inelastic dynamic response analyses of the two structures were conducted with series of inputs of ground motions in a rare earthquake level. The seismic behaviors of the two structures were investigated preliminarily. It was found that the columns and beams of the frames in the frame wall structures did not experienced yielding under strong earthquake, while coupled beams in walls were the major energy dissipation elements with their post yielding plasticity. And the bases of some walls formed hinges as well. The reasons for the frames of dual system remained non yielding states were analyzed and discussed from the aspects of their favorable load carrying state and strengthening measures for them in dual systems in Chinese design codes. A preliminary proposal was made that it may be feasible to loosen moderately some seismic fortification measures concerning the frame in the dual system with a height exceeding 60m on the Zone of Fortification Intensity 8. 相似文献
77.
To find out whether or not the locomotor activity of the Japanese sea catfish, Plotosus lineatus, shows a circadian rhythmicity, the locomotor activity of this catfish was recorded in a laboratory. All of the catfish recorded
(n = 20) showed a nocturnal locomotor activity rhythm under a light–dark (LD) cycle (LD 12:12). The locomotor activity started
after the light was turned off, and declined during the period of darkness. In five of the six catfish we examined, locomotor
activity shifted gradually over the course of 3–4 days in order to synchronize to the LD cycle after it was advanced by 6 h.
Locomotor activity persisted within a constant darkness (DD) in all eight of the catfish. The average free-running period
of locomotor activity under DD lasted for 24.2 ± 0.4 h (mean ± SD). Thus, the present results demonstrate that the Japanese
sea catfish has an endogenous circadian oscillator entrained by an LD cycle. 相似文献
78.
Carole Engle Nilima Renukdas Jeonghwan Park Patrick Rees 《Journal Of Applied Aquaculture》2017,29(3-4):245-255
Alternative management strategies will be required to produce hybrid catfish (♂Ictalurus punctatus X ♀Ictalurus furcatus) year-round to provide continuous market supply. Hybrid catfish fingerlings were stocked at 9,880 head/ha singly or in co-culture with sub-marketable (mean weight = 454 ± 16 g) hybrid catfish carried over the winter from a previous year’s multi-size trial. Economic analyses compared cost of production ($/kg of market-size fish produced) and cash flow of single- and multiple-batch production of hybrid catfish for a single- and two-year period. Gross total and marketable yields were significantly greater in the mixed-size treatment as compared to the single-size treatment, in spite of the significantly greater percentage of market-size fish (84%) in the single-size treatment than in the mixed-size treatment (71%). Cost of production ($/kg) was 4% to 10% lower in the multi-size treatment in the single-year analysis, but 18% to 20% lower when the full two-year cycle was assessed. Cash flow and cash flow risk were improved substantially with the multi-size treatment primarily because the overwintered sub-market-size fish from the previous year reached market size three to four months earlier than in the single-size treatment. 相似文献
79.
E. Jakku 《Agricultural Systems》2010,103(9):675-682
Scientists develop decision support systems (DSSs) to make agricultural science more accessible for farmers and extension officers. Despite the growing use of participatory approaches in agricultural DSS development, reflection on this endeavour has largely focused on the ‘doing’ of participation or the ‘problem of implementation’ when DSSs have not been adopted by stakeholders. There has been little reference to relevant theoretical approaches to the social processes involved in ‘participation’ or ‘implementation’. However, if DSS use is to reach its full potential, a more conceptually informed understanding of how stakeholders collaborate in the participatory development of DSSs is required. To contribute to this conceptualisation, we developed a framework based on three concepts drawn from the field of science and technology studies: technological frames, interpretative flexibility and boundary objects. The framework highlights the importance and value of social learning for participatory DSS development, which relies upon exploring the participating parties’ different perspectives on the agricultural system represented in the DSS. Our framework provides a broad definition of success for participatory DSS development, placing greater weight on learning during the participatory process compared with subsequent use of the DSS by farmers and/or advisors. Two case studies of stakeholder collaboration to develop an irrigation scheduling DSS for sugarcane production were used to explore the relevance of the framework. The concepts in the framework were clearly displayed during the case studies. At the conclusion of the studies there were contrasting outcomes for the DSS. One group of farmers was keen to apply it in their ongoing irrigation management, while another saw little relative advantage in use of the DSS. In both instances co-learning occurred amongst case study participants, so the participatory process was clearly a success. 相似文献
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