Investigations of physiological and pathological levels of total plasma protein in rainbow trout, Oncorhynchus mykiss (Walbaum)

This study was aimed at construction of reference (physiological) value intervals determined by lower 2.5% and upper 97.5% quantiles for total plasma protein (TPP) in farmed rainbow trout, Oncorhychus mykiss (Kamloops strain), aged 10–12 months (n=755). Total plasma protein in male trout from raceway culture was found to be significantly greater (38–58.3 g L^?1) relative to females (31–51.5 g L^?1). Total plasma protein in trout from cage culture was significantly greater (32–54 g L^?1) compared with the raceway culture (31–49 g L^?1). Moderate product–moment correlations between TPP and cholesterol (r=0.8730), TPP and total calcium (r=0.8188), TPP and alanine aminotransferase (r=0.6200) and between TPP and aspartate aminotransferase (r=0.6430) were estimated. Proteinaemia was explained as a metabolic response to feed content, infections of bacterial or viral aetiology or to intoxications.     

确定137Cs背景值所需的采样点数与采样面积

137Cs背景值的确定是利用核示踪技术研究土壤侵蚀的前提和根本,直接关系到侵蚀速率计算的准确与否。而大部分研究对137Cs背景值的确定均采取随机采样,没有统一的采样点数与确定的采样面积。本研究利用网格加密采样法,对未扰动地和长期耕种且未平整的农耕地各两块样地的137Cs背景值空间变异进行了分析,结果表明：在未扰动地与农耕地采样地块,137Cs采样点数与背景值空间变异系数都存在指数回归关系;在未扰动地块137Cs背景值存在较大空间变异性,且随着网格面积的扩大137Cs空间变异系数表现为增加趋势,在0.25m2范围内选取最少11个样点才能满足试验精度;在农耕地采样地块,因长期的耕种作用使得137Cs在耕层中混合相对均匀,137Cs背景值空间变异性显著变小,最少选取7个样点就能满足试验精度,且不受采样面积的影响。     

三倍体虹鳟实时荧光定量PCR内参基因稳定性分析

采用实时荧光定量PCR(qRT-PCR)方法比较甘油醛-3-磷酸脱氢酶(gapdh)、核糖体大亚基蛋白基因(rplp2)、真核延伸因子基因(ef1-α)、β-肌动蛋白(β-actin)和18S核糖体核酸基因(18S rRNA)等5个候选内参基因在体质量约800 g三倍体虹鳟脑、眼、鳃、皮肤、心脏、肾脏(头肾、中肾、后肾...     

中国美利奴羊(新疆型)皮肤组织GAPDH基因实时荧光定量PCR方法的建立

【目的】建立GAPDH内参基因实时荧光定量PCR方法,为进一步研究中国美利奴羊(新疆型)相关基因的定量表达奠定基础。【方法】采用中国美利奴羊(新疆型)皮肤组织为试材,根据Genebank中绵羊GAPDH基因序列,设计并合成一对引物,建立基于SYBR Green I染料技术的Real-Time PCR检测体系,绘制出标准曲线并对其熔解曲线分析。【结果】以cDNA为模板建立的标准曲线循环阈值(Ct)与标准cDNA模板在一定浓度范围内呈良好的线性关系,GAPDH基因标准曲线中模板拷贝数(X)与Ct值的关系为Ct=一3.679 51g/X+35.648,相关系数R=0.999 8;试验重复性好,批内和批间变异系数(CV%)分别为0.22%～3.45%和1.30%～4.89%。【结论】所建立的方法具有快速、线性范围广、重复性强等特点,GAPDH可作为内参基因用于绵羊相关基因的定量表达研究。     

数字图书馆的发展与启示

介绍了当今美国数字图书馆的建设特色,我国数字图书馆的现状与前景,提出美国数字图书馆的建设对我国正在建设的数字图书馆工程起着十分重要的借鉴意义。     

论信息时代图书馆的参考咨询服务

分析了信息时代图书馆参考咨询服务工作的内容和特点,以及对图书馆参考馆员提出了新的更高的要求。并指出了现代参考咨询馆员为适应时代发展所应具备的素质,以及今后对图书馆参考馆员的培养和选拔等。     

国外土地整理实践对我国土地整理的启示

土地整理在我国起步较晚，很多理论还不成熟。采用文献参阅法，从土地整理的发展阶段、内容和特点等方面介绍了德国、俄国和荷兰等国外土地整理的基本情况，并由此得出其对我国土地整理的启示：建立健全土地整理法律政策，重视土地整理的权属调整，拓宽土地整理融资渠道，重视土地整理中的生态环境保护，积极推动土地整理公众参与和高度重视土地整理规划等。     

ECHOCARDIOGRAPHIC REFERENCE VALUES IN WHIPPETS

The aim of the study was to establish reference echocardiographic values for whippets, to compare these values with previously published reference values for the general dog population, and to determine whether there is an influence of gender and breeding lines on echocardiographic measurements. Echocardiographic parameters from 105 apparently healthy whippets without cardiac symptoms were used to establish reference values for the breed and to compare these values with two previously reported reference ranges. The coefficients of the allometric equation Y= aM(b), useful to reconstruct normal M-mode and two-dimensional average values for whippets of varying weights, were calculated, as well as the lower and upper limits of the 95% prediction interval. First, we found that whippets have a significantly larger left ventricular diameter, increased left ventricular wall, and interventricular septum thickness than expected, in diastole as well as in systole. Fractional shortening was significantly lower than the reference value. Second, comparing males and females, taking body weight differences into account, females had a significantly larger left ventricular diameter in diastole and systole. Minor differences were found between racing and show pedigree dogs. In conclusion, the results of this study confirm that breed-specific reference values are needed in echocardiography. In whippets, the values found in this study can be used as references in order to avoid overinterpretation of cardiac dilation, hypertrophy, and/or decreased contractility in these dogs.     

农业机器人田间导航参照点测距的新方法

传统双目视差测距法的测量值为参照点P到双目摄像机基线中心的距离,而农业机器人上的摄像头装置通常被安装在距离地面一定高度,与水平方向呈一定倾角的位置,利用传统双目视差测距法将无法得到导航参照点到机器人机身的水平距离。为此,提出了一种解决农业机器人田间导航参照点测距的新方法。通过改进的BP神经网络标定下的双目系统、改进的SIFT特征匹配,输出导航参照点在世界坐标系下的坐标X,Y),则导航参照点距机器人机身的水平距离可表达为S=(X2+Y2)(1/2)。实验表明:该方法在实际田间测试中的结果最大偏差0.479cm,最小偏差0.032cm,精度高达99%,测距过程耗时共计55ms,计算量较传统双目视差测距显著减小,具有一定的工程实用性与可行性。     

灰色—周期外延组合模型在参考作物腾发量预测中的应用

参考作物腾发量ET0是计算作物需水量、制定灌溉制度和进行水资源优化配置的重要参数之一。因参考作物腾发量随季节性变化,并呈现以年为周期波动的特点;在这种情况下,提出了一种基于灰色GM（1,1）与周期外延相结合的预测模型,即灰色-周期外延组合模型。以沈阳、鞍山、铁岭、盘锦4个地区1997—2006年参考作物腾发量季节值为例进行分析和模拟。结果表明：运用灰色-周期外延组合模型预测参考作物腾发量比原有的GM（1,1）模型预测精度高。该模型预测过程简单,预测结果可靠,适应性强。因此,该模型可广泛的应用于参考作物腾发量的季节预测。