紫花苜蓿幼苗耐盐性的近红外光谱鉴定

紫花苜蓿幼苗耐盐性快速鉴定对于耐盐种质资源筛选和耐盐新品种选育具有重要意义。脯氨酸和丙二醛是表征植物耐盐性的两种重要生化指标。研究应用便携式近红外仪和近红外光谱分析技术,结合偏最小二乘回归法,研究了40个不同紫花苜蓿品种幼苗耐盐性的脯氨酸和丙二醛含量,建立了新鲜样品和干燥样品的近红外漫反射光谱定量分析模型。研究结果表明：脯氨酸、丙二醛的近红外漫反射光谱分析效果均较好,校正模型决定系数R2 和验证集样品预测值与常规分析测定值的验证决定系数r2都大于0.85,两种样品脯氨酸的相对分析误差RPD值分别为1.72     

信息时代高校图书馆发展的探讨

从信息技术对高校图书馆管理的影响、当前图书馆管理存在的问题及管理与发展中的几点建议等三个方面,对信息时代下图书馆的发展进行分析,为高校图书馆事业的发展提供了建设性意见。     

同仁地区中小学信息技术教育的现状与思考

近几年,随着信息技术的飞速发展和国家对教育事业的不断投入,青海省在中小学信息技术教育方面有了长足的进步和发展,但与发达地区相比,仍存在很大差距,还有许多工作要做。就青海省黄南藏族自治州同仁地区中小学信息技术教育的现状进行了调查研究,分析了存在的问题,并结合藏区的教育实际,提出了切实可行的具体措施。     

Prediction of grain protein in spring malting barley grown in northern Europe

The ability to predict grain protein concentration at harvest (CP) in Swedish malting barley (Hordeum distichum) from observations of soil conditions, sowing day, fertilisation rate, remote sensing at early stem elongation and the temperature sum during grain filling, was tested for two cultivars; Astoria (Secobra, France) and Wikingett (Svalöf-Weibulls, Sweden) in 16 fertilisation trials in southern Sweden, encompassing 3 years (2001–2003). Fertilisation was applied either as a single dose at sowing, or as both a starting application and an application at early stem elongation. The highest total application rate was 160 kg N ha⁻¹ y⁻¹. The soil was analysed for phosphorus, potassium, magnesium and calcium in the layer 0–0.3 m, and mineral N down to 0.6 m. Canopy reflectance observations at BBCH 32 was used to calculate a vegetation index (TCARI(32)) to reflect the canopy (leaf and straw) chlorophyll concentration. Harvested grain CP correlated only marginally with the observed soil variables. It was, however, for a specific cultivar, possible to make a prediction of grain CP based on day of sowing and TCARI(32) with . Part of the sowing day effect might be due to thermal stress during grain filling, as the risk for high temperatures during this phase was higher when sowing was late. This might also explain why the introduction of accumulated temperature during grain filling, into a model already including sowing day and TCARI(32) as independent variables, did not improve the predictability of grain CP.     

The conceptual basis for a decision support framework to assess the risk of phosphorus loss at the field scale across Europe

We report a conceptual framework for a simple screening tool to evaluate the vulnerability of different fields in the landscape to phosphorus (P) loss within the European agricultural context. Our work builds on the principles established for the P Index system developed in the United States. We examine the differing needs and criteria for a range of EU member states and EFTA countries and highlight essential and optional criteria for inclusion in the decision support framework depending on their ecoregional characteristics. A framework such as this, meets in principle, the needs of the COST832 Action ‘Quantifying the Agricultural Contribution to Eutrophication’ as it deals with diffuse nutrient sources from agriculture, and aids more targeted use of practical strategies to mitigate nutrient losses to minimise the potential for the eutrophication of receiving waters.     

大学生网络依恋的心理分析及对策

占领网络宣传的科技阵地,增强大学生的时代感、责任心,是历史赋予我们的使命。高校大学生中的‘网虫”现象,对其学习、生活、成长产生不良影响。我们应该从心理障碍入手,为大学生营造一个良好的网络环境。     

两种声速测定实验方法的比较

本文探讨在声速测定实验中关于声波在空气中，在发射器和接收器之间反射形成及极大值的位置和条件，以及比较共鸣法测声速和超声速测声速的规律，有利于人们正确深入理解声波特性和探讨声速测量实验方法。     

高山草地的光谱反射特征及其估产模型

对祁连山东段高山草地中５种植物群落的光谱反射特征进行了测试研究。结果表明：１）草本植物和灌木种群的光谱反射率在可见光波段上无显著差异，但在近红外波段存在显著差异；２）土壤背景和测试仪器高度对群落的光谱反射产生显著影响；３）植物生长盛期，可用近红外波段的反射差异来区分草地植物群落的空间分布：４）草地植物群落的地上植物量与几种变换的植被指数呈显著或极显著的非线性相关。     

Impacts of intensification of pastoral agriculture on soils: Current and emerging challenges and implications for future land uses

Abstract

AIM: To find evidence for localisation in the uterus, and fetal infection, of Leptospira spp. in farmed deer in the lower North Island of New Zealand during and shortly after the breeding season.

METHODS: Between February and July 2008, 116 blood samples, 120 kidneys, 120 uteri and 27 fetuses were collected from 120 mixed-age hinds from lines from nine farms, at a deer slaughter premises. Serum samples were tested for antibodies against Leptospira borgpetersenii serovar Hardjo-bovis and Leptospira interrogans serovar Pomona, using the microscopic agglutination test (MAT). For both serovars, a titre of >1:48 was considered positive. Samples from kidneys, uteri and fetal tissue were subjected to bacterial culture, using Ellinghausen-McCullough-Johnson-Harris (EMJH) medium, and real-time PCR, using DNA gyrase subunit B gene primers.

RESULTS: Thirty-four of 116 (29.3%) serum samples were positive for serovar Hardjo-bovis, and 13 (11.2%) for serovar Pomona. Seven of 120 kidneys were positive for serovar Hardjo-bovis by culture, and five of these, but no others, were positive by real-time PCR. Of 120 uteri, none was culture- or PCR-positive. None of 27 fetal samples was culture-positive but one was positive by real-time PCR. The dam of the PCR-positive fetus was culture-negative from the kidney, but had an MAT titre of 1:192 for Hardjo-bovis.

CONCLUSIONS: Attempts to isolate Leptospira spp. from the genital tracts and early fetuses of farmed deer were unsuccessful. However, molecular evidence suggested fetal infection in one case. This finding justifies further study of the role of leptospires in the genital tract and fetus and its association with reproductive loss in farmed deer.