The effects of vitamin E on non-specific immune response of the juvenile soft-shelled turtle <Emphasis Type="Italic">Pelodiscus sinensis</Emphasis>

ABSTRACT:   This study was conducted to determine the effect of dietary vitamin E supplements on non-specific immune responses in juvenile soft-shelled turtles. Turtles were fed diets supplemented with vitamin E at 0 (control), 50, 250, 500, 1000 and 5000 mg/kg, respectively, for 4 weeks. Results showed that blood cell phagocytosis and serum bactericidal activity were significantly improved in turtles from two diets (250 and 500 mg/kg vitamin E supplementation), while had no significant improvement in turtles from the three remaining diets (50, 1000 and 5000 mg/kg vitamin E supplementation) when compared to turtles from the control group. Serum bacteriolytic activity in turtles from diets with 50, 250, 500 and 1000 mg/kg vitamin E supplementation were higher than activity levels quantified for the control group, but no significant difference was observed between the 5000 mg/kg vitamin E supplementation diet and the control diet. The results suggest that vitamin E has an upper and lower threshold for improving non-specific immune function in soft-shelled turtles, and the optimal supplementation may be between 250 and 500 mg/kg.     

Effect of dietary vitamin C supplementation on the oxygen consumption, ammonia-N excretion and Na/K ATPase of Macrobrachium nipponense exposed to ambient ammonia

The 96-h LC₅₀ of ammonia-N and the effects of dietary vitamin C on oxygen consumption, ammonia-N excretion and Na⁺/K⁺ ATPase activity of Macrobrachium nipponense exposed to ambient ammonia were investigated. The results showed that the 96-h LC₅₀ of ammonia-N was 36.6 mg l⁻¹ for the freshwater prawn, M. nipponense, at pH 8.0. When prawns were exposed to high ambient ammonia-N concentrations, the oxygen consumption rate increased and ammonia excretion decreased. Dietary vitamin C supplementation led to higher oxygen consumption and lower ammonia excretion. Na⁺/K⁺ ATPase activity increased with increased ambient ammonia-N exposure in the range of 0–18.3 mg l⁻¹, and then was reduced at ambient ammonia-N 36.6 mg l⁻¹. Na⁺/K⁺ ATPase activities of prawns fed a vitamin C-supplemented diet were significantly lower than those of prawns fed a diet which was not supplemented with vitamin C.     

城镇土地定级中结点评价方法的探讨

目前我国的城镇土地定级工作已拉开序幕,随着城镇土地定级工作的不断发展,必然会出现许多新的理论问题和技术问题,研究和解决这些问题对于不断充实和完善城镇土地定级工作的方法理论体系,不断提高城镇土地定级工作的效率,质量和水平都具有十分重要的意义。本文针对单元评价中遇到的一些实际问题,提出了结点评价的粗浅看法,希望有助于这方面研究工作的继续深入和发展。     

Identification of insulin-like growth factor I gene polymorphisms using high-resolution melting and its effect on growth traits in sinipercid species

The aim of this study is to screen single nucleotide polymorphisms (SNPs) of the insulin-like growth factor I (IGF-I) gene and analyze the potential association between IGF-I gene polymorphisms and growth traits in a crossing sinipercid population. Two SNPs (g.A321G, g.A537G) within five exons of the IGF-I gene were tested for association with four growth traits in 250 individuals using the high-resolution melting method. The association analysis of SNPs of IGF-I gene with the four growth traits was carried out using General Linear Model estimation. Results indicated that SNP1 in exon3 of the IGF-I gene was significantly associated with body weight (P < 0.05), body length (P < 0.05) and body width (P < 0.05), and SNP2 in exon5 of the IGF-I gene was significantly associated with body weight (P < 0.05), body depth (P < 0.05) and body width (P < 0.05) in a sinipercid population. The individuals of genotype AA or AG in loci SNP1 and SNP2 grew faster than those of genotype GG. Diplotypes did not show significant effects on growth traits. These findings implied that the two SNPs of the IGF-I gene affecting growth traits could be potential quantitative trait nucleotides and would be useful genetic markers in the selection of some growth traits for developing improved culture lines of sinipercid species in China.     

Development of an enzyme-linked immunosorbent assay (ELISA) for vitellogenin measurement in greenback flounder Rhombosolea tapirina

Vitellogenin (Vtg) was purified from the plasma of 17-estradiol (E₂)-injected male greenback flounder,Rhombosolea tapirina. The molecular weight of the native Vtg was estimated by gel filtration as 540 kD. SDS-PAGE and Western blotting analyses indicated that this protein consisted of three bands with molecular weights of 155, 104, 79 kD, respectively. A polyclonal antibody against the highest molecular weight band of putative Vtg was generated in sheep and an indirect antibody-capture competitive enzyme-linked immunosorbent assay (ELISA) was developed. The assay was validatedfor plasma Vtg measurement in greenback flounder. Serial dilutions of plasma from vitellogenic females parallelled the standard Vtg curve, whereas no cross-reaction was observed with the plasma of males in the ELISA. The Vtg ELISA was used to assess the induction of Vtg by E₂ in vivo in males. The induction of Vtg in greenback flounder showed a time- and dose-dependent response as in other species. In E₂-treated fish, detectable levels of Vtg were first found at 48 h, and reached a peak at 96 h post-injection. Plasma levels of Vtg increased as the E2 dose increased with a threshold of 0.1 mg kg^–1.     

Standardizing catch and effort data of the Taiwanese distant-water longline fishery in the western and central Pacific Ocean for bigeye tuna, Thunnus obesus

Catch per unit effort (CPUE) is often used as an index of relative abundance in fisheries stock assessments. However, the trends in nominal CPUE can be influenced by many factors in addition to stock abundance, including the choice of fishing location and target species, and environmental conditions. Consequently, catch and effort data are usually ‘standardized’ to remove the impact of such factors. Standardized CPUE for bigeye tuna, Thunnus obesus, caught by the Taiwanese distant-water longline fishery in the western and central Pacific Ocean (WCPO) for 1964–2004 were derived using three alternative approaches (GLM, GAM and the delta approach), and sensitivity was explored to whether catch-rates of yellowfin tuna and albacore tuna are included in the analyses. Year, latitude, and the catch-rate of yellowfin explained the most of the deviance (32–49%, depending on model configuration) and were identified consistently among methods, while trends in standardized catch-rate differed spatially. However, the trends in standardized catch-rates by area were found to be relatively insensitive to the approach used for standardization, including whether the catch-rates of yellowfin and albacore were included in the analyses.     

HUDACAPP— 一种工艺规程自动设计系统

本文介绍浦沅工程机械总厂准柔性制造系统(P-FMS)中加工箱体零件所用的一个工艺规程自动设计系统—HUDACAPP,阐述了系统的原理、结构和实现.给出了实例.本系统能按零件输入信息自动生成工艺过程,选择机床、夹具、刀具、量具、切削参数以及计算工时,并能与P-FMS的实时管理调度软件联接,提供所需的资料.     

近红外多组分分析中异常样本识别方法

近红外光谱分析中,异常样本的存在严重影响定标模型的预测性能和适配性。基于 X / Y 联合的ODXY异常样本识别和剔除方法,提出并证明了一种专用于多组分分析的MODXY异常样本识别方法。实验采用80组玉米近红外光谱数据,利用不同异常样本识别方法剔除异常样本后建立玉米含水率、含油率、蛋白质含量和淀粉含量4种组分的偏最小二乘预测模型,采用预测均方差和决定系数作为评价指标比较所建模型的性能,检验MODXY方法在多组分分析中的异常样本识别能力。实验结果表明：在近红外多组分分析中,MODXY方法在大多数情况下具有更好的异常样本识别能力;MODXY方法和ODXY方法均有一定的适用范围,它们更适合于相应组分化学值的相对标准偏差较大的情况。     

STUDY ON THE DEVELOPMENT AND FEEDING MANAGEMENT OF YOUNG DEMOISELLE CRANES

DemofsellecraneisthesmalleStoneofallcrans,ithasgreatdistributioninChinaandhasvarioushabitatThebredngareaismoStiylocatedineastInnerMongchaAUtonomousedOn,HeilowiirePrednceandWesternhlinPrOvince.ItwigratshereinthendddleofMarh,laysopboearyMaytothendddleofJune,andbonstondgratetothesouthinthelateoctobe.TherearelotsofreportSaboutecolOgicalndesOfbooiselecranes,butfewreportSabootthedeveoPInenofneshiop.TherehasbeenafewstUdiesaboutedngofdemoisel1ecranesinsomezoosinChina.msresearchmaterialisfrOm…     

草鱼、鲢、鳙秋繁及其对次年春繁的影响

1991年秋催产草鱼、鲂、鲢、鳙亲鱼256组,共获鱼苗5040万尾。平均催产率78.2%,受精率71.9%,孵化率75.4%。秋繁鱼苗当年可育成10cm以上鲢、鳙鱼种和8cm以上草鱼、鲂鱼种。鱼苗到鱼种成活率为37.2%。秋繁亲鱼次年春繁催产率、受精率和孵化率基本不受影响,产卵量比往年未秋繁者低6.8%～9.6%,卵径、卵粒重和鱼苗体长等无显著差异。草鱼、鲢、鳙卵母细胞发育不同步,春繁后经60天左右强化培育,卵巢中未成熟的卵母细胞可发育成熟。