Immunohistochemical study on changes in gill Na+/K+-ATPase α-subunit during smoltification in the wild masu salmon, Oncorhynchus masou

Changes in immunoreactivity of Na⁺/K⁺-ATPase 06x173u11w528r/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-subunit in gill sections of wild masu salmon (Oncorhynchus masou) during the parr-smolt transformation (smoltification) were compared with changes in gill Na⁺/K⁺-ATPase specific activity. Gill Na⁺/K⁺-ATPase specific activity increased from April and peaked in May. Immunohistochemical analysis, using an antiserum against a synthetic oligopeptide based on the conserved region of the Na⁺/K⁺-ATPase 06x173u11w528r/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-subunit, revealed that immunoreactivity was confined to chloride cells in the surface layer of primary lamellae and the proximal end of secondary lamellae. The size and number of these cells increased gradually from February to May; however, the number of chloride cells of the secondary lamellae decreased in May. These data suggest that the synthesis of Na⁺/K⁺-ATPase and the proliferation of chloride cells occur prior to the elevation of enzyme activity. Moreover, it is likely the proliferation and hypertrophy of chloride cells on primary lamellae prepare smolts for entry into seawater and migration in the ocean.     

Effects of dietary lipids on body composition and liver function in juvenile red drum, Sciaenops ocellatus

This study was conducted to evaluate the effects of different concentrations of dietary lipids on body composition and liver function in juvenile red drum, Sciaenops ocellatus. Diets were formulated to contain 40% crude protein from solvent-extracted menhaden fish meal and 0, 7, 14 or 21% lipid from menhaden fish oil. The basal diet, without supplemental fish oil, contained lipid at 0.4% of dry weight. The diets were fed to groups of 25 juvenile red drum initially averaging 7.3 ± 0.18 g fish^013;1 in a recirculating culture system for 8 weeks and weight gain was recorded. After an additional 8 weeks, 16 fish from each treatment were sacrificed and the following measurements were recorded: hepatosomatic index (HSI), intraperitoneal fat (IPF) ratio, and liver 01p66812j7/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-tocopherol, malondialdehyde (MDA) formation, and cytochrome P-4501A activity (measured as 7-ethoxyresorufin O-deethylase (EROD) activity). The activity of alanine and aspartate aminotransferases and concentrations of 01p66812j7/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-tocopherol also were measured in plasma.Weight gain was significantly (p<0.05) affected by dietary lipid concentration, with values ranging from 361% of initial weight for fish fed the basal diet to 527% of initial weight for fish fed the diet containing 7% lipid. The HSI and IPF ratio values also were significantly affected by lipid with the lowest values recorded for fish fed the basal diet and the highest values observed in fish fed the diet containing 21% lipid. Increasing dietary lipid significantly increased oxidative stress as reflected in reduced 01p66812j7/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-tocopherol in liver and plasma and increased MDA formation in the liver, although no overt pathological signs were observed. These findings suggest that lipid concentrations between 7 and 14%, when the diet contains 60 IU vitamin E kg^013;1, are likely to limit oxidative stress and result in normal physiological responses of red drum.     

ORACLE疑难错误解析

ORACLE数据库是目前世界上最流行的大型关系数据库,SQL*PLUS是ORACLE高效的编程工具,也是用户同ORACLE进行交互的窗口。在使用SQL*PLUS的过程中,会碰到各种各样的错误,本文提供使用SQL*PLUS时碰到的看似简单、原因复杂的常见错误原因及解决办法。     

应用热扩散技术对柠条锦鸡儿主根液流速率的研究

运用热扩散技术对柠条锦鸡儿根部液流速率(Fs)进行连续测定,同步进行环境要素的实时监测。选择2008年4—10月30天典型晴天日观测数据。结果表明:1)Fs在晴天日表现出典型的宽峰型正态分布,可划分为4个特征差异明显的阶段,反映了大气环境因子对液流的直接驱动效应,以及柠条锦鸡儿叶片气孔行为对液流变化的调控作用。2)液流的变化受多个环境因子共同驱动,其中潜在蒸发散(ET0)综合性强、与Fs相关紧密,是分析液流特征更为可靠的复合型环境变量。Fs与主要环境因子间的耦合关系因时段而异,在早晨启动的液流上升阶段,Fs与太阳辐射、ET0间均呈线性关系,反映了太阳辐射等因子对液流的驱动与对光合作用的激活效应,而在峰值后的下降阶段基本呈Sigmoidal-Hill函数关系;Fs随大气水分亏缺(VPD)的变化与随太阳辐射、ET0的变化趋势相反,表明VPD在达到一定值后启动气孔调节行为以及抑制过度蒸腾耗水的效应。3)柠条锦鸡儿根部Fs与主要环境要素间的变化近似同步,试验期间没有出现典型的时滞现象。4)在整个生长季的大部分时间内观测到柠条锦鸡儿根部夜间持续存在着液流现象,夜间液流量平均占全天液流量的3.83%。试验结果可例证热扩散技术在根部测定液流并用来计算灌木树种单株耗水方法的科学性与优越性。     

SAD和FAD家族基因调控山核桃不饱和脂肪酸组分配比

以山核桃胚为试材,测定5个山核桃油脂合成积累关键时期(授粉后75、85、100、109和127 d)的油脂组分和油含量,并利用实时荧光定量PCR检测山核桃Δ9–硬脂酰–ACP脱氢酶(SAD)基因(CcSAD-1、CcSAD-2、CcSAD-3)和山核桃脂肪酸去饱和酶(FAD)基因(CcFAD2、CcFAD3-1、CcFAD3-2、CcFAD3-3、CcFAD6、CcFAD7、CcFAD8-1、CcFAD8-2、CcFAD8-3)的表达模式。结果表明:成熟的山核桃种仁含油率超过种仁干质量的70%,同时不饱和脂肪酸比例达到90%以上;山核桃5个时期的脂肪酸组分,主要由棕榈酸(C16︰0)、硬脂酸(C18︰0)、油酸(C18︰1)、亚油酸(C18︰2)以及亚麻酸(C18︰3)组成;随着山核桃SAD家族基因表达上升,山核桃油中的油酸含量上升并维持一定水平,其中CcSAD-3可能是影响油酸含量的主效基因;同时随着山核桃油酸含量上升,CcFADs基因表达上升,山核桃不饱和脂肪酸比例增加。     

中籼898产量构成及高产栽培措施研究

对中籼 898产量构成因素的分析表明 ,4个产量构成因素对产量贡献的大小依次为有效穗、每穗总粒数、结实率、千粒重。产量 9.0t/hm2 以上的合理穗粒结构为 :有效穗 (2 85± 15 )万 /hm2 ,每穗总粒数 (16 0± 10 )粒 ,结实率 (86± 2 ) % ,千粒重 2 9.5g。并提出高产栽培措施。     

基于支持向量机优化粒子群算法的作物生育期ET_0预测

ET0是计算作物需水量、进行农田灌溉管理及区域水资源优化配置的重要依据。为了提高ET0的预测精度,将粒子群(particle swarm optimization,PSO)算法引入到ET0预测中,并用支持向量回归机(support vector machine,SVM)优化参数。PSO-SVM将最高气温、最低气温、相对湿度、平均风速与日照时数输入到SVM中学习,将SVM参数作为PSO中的粒子,把ET0值作为PSO的目标函数,然后通过粒子之间相互协作得到SVM最优参数,对ET0进行预测,并采用PM模型计算值验证。该文以新疆喀什地区为例,通过采用粒子群耦合支持向量机(PSO-SVM)算法训练得到模型,并用10组数据进行预测;最后引用BP神经网络算法和PSO-SVM算法进行了对比,其结果表明,PSO-SVM算法预测准确率较高,预测值与实测值间相关系数达0.682,平均相对误差为3.19%。     

基于公共天气预报的三江平原ET0预报模型比较及敏感性分析

为了提出适合我国三江平原的高精度ET0预报方法,基于该区6个气象站点的天气预报数据和实测气象数据,以FAO56-Penman-Monteith(FAO56-PM)公式计算值为基准,比较Hargreaves-Samani(HS)、Thornthwaite(TH)和Blaney-Criddle(BC)3个ET₀预报模型的效果,对最优模型进行敏感性分析。结果表明:3个模型1~7 d预见期平均绝对误差均值分别为0.66、0.65、0.65 mm/d,均方根误差分别为0.93、0.96、0.95 mm/d,相关系数分别为0.857、0.828、0.840。1~5 d预见期最优预报模型为HS模型,6~7 d为TH模型。总体上预报精度由高到低为HS、TH、BC模型,建议采用HS模型在三江平原开展ET₀预报,HS模型预报对最高温预报的敏感性大于最低温。其预报值在夏季受温度预报误差影响最大,冬季最小,4季整体误差较小。研究可为灌溉预报提供较准确的数据基础。     

牙鲆仔鱼早期阶段的摄食能力

本文主要在实际观察值的基础上,利用发育反应方程Ｃ＝ＫＷ＾ｙ与功能反应Ｈｏｌｌｉｎｇ、Ｉｖｌｅｖ方程对２～１０日龄的牙鲆仔鱼的摄食能力进行了计算与预测。其结果表明：牙鲆仔鱼在２～６日龄、轮虫饵料密度不超过３０００ｉｎｄ．Ｌ＾－１的水体中,摄食强度不超过１．７μｇ．ｈ＾－１;随着日龄的增加,摄食强度迅速增强,在４、６、１０日龄、饵料密度为３０００ｉｎｄ．Ｌ＾－１的水体中,摄食强度分别是１．３５、１．６