光谱异质性参数优化方法及其在QuickBird影像中的应用

提出了一种光谱异质性参数优化方法,与现有方法相比,新方法的改进主要有:①在设置参与分割的波段数据时,通过引入派生波段数据来增强分割判据的数据支撑;②在设置各波段数据层的权值时,综合考虑了各波段数据层包含的信息量和相互间的信息相关度,以抑制波段数据层间的信息冗余对分割过程的不利影响.最后,通过分割对比实验证明:采用新方法设置的光谱异质性参数执行影像分割,“欠分割”现象有了较大幅度地减少,对象间的差异程度和对象内部的均质程度都得到了提高,分割质量有了明显地改善.     

青蒿花序轴离体培养的初步研究

以不同基因型(青蒿素含量1.3％以上)的花序轴为外植体进行离体培养,初步建立了不同基因型的再生体系。结果表明,以MS基本培养基进行诱导培养时,附加6-BA 1.0～3.0 mg/L+NAA 0.1-0.5 mg/L能直接从愈伤组织块诱导出不定芽,且不同基因型诱导的激素浓度不同。再生植株的株系培养,附加低浓度的6-BA 0.1~0-3 mg/L+NAA 0.05-0.1 mg/L则有利于快速生长成苗,同时附加IAA或GA3对其生长也有一定好处,但主要与基因型相关。     

应用线粒体DNA鉴定动物源性饲料成分研究进展

为避免牛海绵状脑病和羊痒病疫区的蛋白饲料进口造成畜牧业上的经济损失,世界各国纷纷开展用分子生物学方法检测牛、羊源性蛋白饲料,本文就运用分子生物学方法有效检测动物物种间线粒体DNA特异性以确认动物源性蛋白饲料成分的来源作出阐述。     

Cartilage-derived retinoic acid-sensitive protein in equine synovial fluid from healthy and diseased joints

Reasons for performing study: More sensitive and specific diagnostic methods for early detection of changes in the joint cartilage are needed. Cartilage‐derived retinoic acid‐sensitive protein (CD‐RAP) is a potential marker of cartilage synthesis and regeneration. This is the first study on equine CD‐RAP. Objectives: To evaluate the ability of a commercially available human sandwich ELISA assay to detect equine CD‐RAP in synovial fluid from healthy and diseased joints. Methods: Synovial fluid was collected from 28 horses with no signs of joint disease and from 5 with induced inflammatory arthritis. CD‐RAP concentrations were measured using a human CD‐RAP ELISA. Intra‐ and interassay imprecision of the assay were evaluated by multiple measurements on pools of equine synovial fluid. Assay inaccuracy was determined by linearity under dilution. Results: The assay showed moderate to large intra‐ and interassay variation when applied to equine synovial fluid. Equine CD‐RAP was detected in synovial fluid from healthy horses ranged at 8.2–52 ng/ml. Repeated arthrocentesis (after injection of isotonic saline), age, joint or gender did not significantly affect CD‐RAP concentrations. Twelve hours after intra‐articular injection of lipopolysaccharide, concentrations of CD‐RAP were significantly lower than after injection of isotonic saline and remained significantly lower until the end of the study at 144 h. Conclusion and potential relevance: The assay is suitable for longitudinal monitoring of CD‐RAP concentration in individual horses. Disease significantly influenced CD‐RAP levels. Similar to previous results obtained in man, CD‐RAP seems to be a marker of cartilage synthesis and/or regeneration in horses.     

阿维菌素类药物在动物性食品中的残留检测研究概况

为了对动物性食品中阿维菌素类残留研究有更深入、全面的了解,并为我国开展阿维菌素类残留检测提供参考,文章综述了阿维菌素类药物(包括阿维菌素、伊维菌素、多拉菌素、依立菌素和莫西菌素)在动物性食品中的单残留和多残留检测方法,包括薄层色谱法、酶联免疫法、高效液相色谱法、液质联用法和液相色谱?质谱?质谱联用法。     

进口饲料中牛源性与转基因成分的检测

本文介绍了进口饲料中牛源性与转基因成分的PCR检测方法。该方法用异硫氰酸胍提取进口饲料样品DNA,以牛特异性引物扩增模板DNA,扩增产物为271bp,PCR产物经限制性酶切片段分析,与预期设想一致;方法灵敏度实验结果显示,饲料样品中含有0.1%的牛源性成分时仍能检出。同时,根据转基因农作物最常使用的外源基因设计引物,在进口饲料中检测出35S启动子和NOS中止子等转基因成分,具有快速、简便、准确等特点。     

浅析动物源性食品安全隐患及解决办法

随着我国经济的持续发展和人民生活水平的不断提高,人们对动物源性食品的需求产生了由量到质的转变,动物源性食品安全问题也逐渐显露,对公共卫生安全和人类的健康已造成严重的威胁,引起了各方面的高度重视。文章针对目前动物源性食品安全现状,对其存在的问题及带来的危害提出相应的解决办法,以保证动物产品的健康使用,促进畜牧业的迅速发展。     

湖州不同林型建群种生物量格局的研究

对湖州林区不同林型建群种生物量格局进行了研究分析 .湖州主要森林类型生物量的平均值变动于 8.2 5～ 1 0 0 .85 t/hm2 之间 ,单因素方差分析表明不同林型林木总生物量差异极显著 ,其中阔叶林最高为 1 0 0 .85 t/hm2 ,灌木林最低为 8.2 5 t/hm2 .多重比较 ( LSD)分析了不同林型林木两两之间生物量的差异性 ,其显著性差异程度因参比林种不同而异 .林木生物量与环境因子相关 ,经逐步回归统计分析筛选出影响不同林木生物量的主导生态因子 ,其回归性达到显著或极显著水平     

Dinitrogen fixation activity of Azorhizobium caulinodans in the rice (Oryza sativa L.) rhizosphere assessed by nitrogen balance and nitrogen-15 dilution methods

 Azorhizobium caulinodans was directly inoculated onto rice plants in three short-term pot trials. Addition of increasing amounts of sucrose (23, 46, 92 kg ha^–1) did not influence the N economy of the A. caulinodans-rice association during the early vegetative growth stage. A. caulinodans inoculation alone and in combination with the highest amount of sucrose had a significantly positive effect on the N balance, with small but significant N gains in the system. Application of 60 kg urea-N ha^–1 had a negative impact on the N economy of the inoculated treatments. N losses increased and the amount of atmospheric N₂ fixed and incorporated decreased significantly as compared to the amounts under the 20 kg urea-N ha^–1 regime. However, N losses were low – a maximum of 8% – at the early vegetative growth stage under the conditions of the experiments. C limitation does not seem to be a limiting factor for the incorporation of fixed N₂ in this bacteria-plant association. Biological N₂ fixation caused by A. caulinodans inoculation was responsible for 14% of the plant N at the vegetative growth stage and under low N conditions. Received: 30 January 2000