鸡新城疫病毒B_(95)株的RT-PCR检测方法研究

本试验设计了一对B95 株的特异引物NDV -P1/P2,探讨了对其进行RT-PCR检测的可行性。结果证明 ,用该引物可以扩增出一条310bp的特异核酸带 ,敏感性为0.0043ng/ul。     

Change in spatial characteristics of forest openings in the Klamath Mountains of northwestern California,USA

Change in the spatial characteristics of forest openings was investigated in three forested watersheds in north-western Siskiyou County, California totalling approximately 24,600 hectares. Watersheds with minimal human disturbance were chosen for study. However, fire suppression has been pervasive throughout. Characteristics of forest openings (area, perimeter, distance between neighboring openings) were measured on aerial photographs taken 41 years apart. An index of regional form was determined for the landscape. Shape complexity for each opening was calculated using two indices based upon fractals. Significant differences were found using the Kolmogorov-Smirnov two-sample test between the perimeters, areas, distance from sample point to nearest opening, and distance between neighboring openings. The perimeters and areas became smaller, and the distances from the sample point to the nearest opening and between neighboring openings became greater over the 41 years between aerial photo sets. The estimated area occupied by openings decreased from 25.8 % to 15.6 % of the study area. No significant difference was found in the shape of the openings except as the shape indices were influenced by changes in size of the openings.This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain and not subject to copyright.     

不同包被液对ELISA检测五号病病毒抗体的比较试验

０．０５ＭｐＨ９．６碳酸盐缓冲液和０．０５ＭＰＨ１３ＮａＯＨ溶液作为包被液，分别用于间接ＥＬＩＳＡ检测乙型五号病病毒抗体。结果表明，用０．０５ＭＰＨ１３ＮａＯＨ溶泡包被可完全灭活五号病病毒抗原而用０．０５ＭＰＨ９．６碳酸盐缓冲液却有８７％的五号病病毒抗原未被杀灭；用于检测时，以０．０５ＭＰＨ１３ＮａＯＨ溶液为包被液在敏感性及检测结果的梯度方面都优于用０．０５ＭＰＨ９．６碳酸盐缓冲液。     

妊娠黄牛的血液动力流变学观察

首次应用XXG－A型心血管功能测试仪以无创伤检测技术对16例妊娠黄牛22项血液动力流变学指标做了检测，并首次对怀孕黄牛的血液动力流变学特征做了报道。     

Development of a semi-selective medium and an immunofluorescence colony-staining procedure for the detection of Clavibacter michiganensis subsp. sepedonicus in cattle manure slurry

Various compounds and basal media were tested for their suitability to create a semi-selective medium for isolation ofClavibacter michiganensis subsp.sepedonicus (Cms) from cattle manure slurry containing c. 10⁸ colony forming units (cfu) per ml.Plating efficiency of Cms in yeast glucose mineral medium (YGM) was 104% compared with yeast peptone glucose medium. Nalidixic acid, polymyxin B sulphate and the experimental disinfectant S-0208 inhibited colony growth of cattle slurry bacteria as compared with Cms in YGM. The optimal concentration of these inhibitors in combination was determined by modified agar diffusion tests and by pour plating in 24-well tissue culture plates. The semi-selective medium YGMI consisted of YGM supplemented with nalidixic acid (2 mg/l), polymyxin B sulphate (30 mg/l) and S-0208 (125 mg/l). Plating efficiency varied for Cms between 50.9 and 69.6%, for cattle slurry bacteria between 1.8 and 2.5% and for saprophytes from potato heel end extracts between 11.5 and 27.4%.Differentiation of Cms colonies from other colonies was based on their small and bluish colony morphology in pour plates and on immunofluorescence colony-staining (IFC). IFC of a pure culture of micro colonies of Cms in YGM was possible after one day incubation (colonies c. 5 cells). Green background fluorescence in the agar gels was prevented by addition of Tween 20 (0.1%) to the washing buffer and the use of 1% agar gels. IFC of macro colonies of Cms in YGMI, visible with 4x objective magnification, was possible after 4 days. The detection level of the target organism in artificially inoculated cattle slurry in YGMI based on colony morphology varied between 1.4×10³ and 2.3×10⁴ cfu per ml of cattle slurry. Miniaturized plating combined with IFC, using wells in tissue culture plates (=16 mm), proved suitable for detection, but was c. 30 times les sensitive. The recovery of Cms was negatively correlated with the number of saprophytic colonies in the agar plates (R ²=0.74).     

A review of models of landscape change

Models of landscape change may serve a variety of purposes, from exploring the interaction of natural processes to evaluating proposed management treatments. These models can be categorized as either whole landscape models, distributional landscape models, or spatial landscape models, depending on the amount of detail included in the models. Distributional models, while widely used, exclude spatial detail important for most landscape ecological research. Spatial models require substantial data, now more readily available, via remote sensing, and more easily manipulated, in geographical information systems. In spite of these technical advances, spatial modelling is poorly developed, largely because landscape change itself is poorly understood.To facilitate further development of landscape models I suggest (1) empirical multivariate studies of landscape change, (2) modelling of individual landscape processes, (3) explicit study of the effect of model scale on model behavior, and (4) scaling-up results of studies, on smaller land areas, that have landscape relevance.     

陆地棉核雄性不育材料在山东不同地区的育性转变及应用研究

对在山东的济南、平度、莱西、烟台种植的几种陆地棉（Ｇｏｓｓｙｐｉｕｍ　ｈｉｒｓｕｔｕｍＬ．）核雄性不育材料的育性表现进行了研究,结果表明：洞Ａ不育系的衍生材料ＭＢ、ＭＡ在不同气候条件下有育性的变化。在济南高度不育,可作为不育系。在其他几个地区表现不同程度的可育。其中ＭＢ在平度有相当好的育性,能正常结铃。而双隐性核不育材料５９Ａ、６２Ａ未能观察到育性变化。本文就核不育材料在棉花杂交制种中的应用前景及需深入研究的问题作了探讨。     

苹果退绿叶斑病毒组织印迹的免疫法检测与定位

用组织培养技术将富士苹果茎尖外植体建立在ＭＳ培养基中,形成试管苗。取４—６周龄的茎与愈伤组织,徒手切取约１ｍｍ厚的横切面,印迹在硝化纤维膜上。印迹组织经封闭后,与ＣＬＳＶ碱性磷酸酶标抗体反应。对反应结果进行显色。感染ＣＬＳＶ的印迹组织呈紫色反应,正常组织无显色反应。结果表明,该方法十分容易检测印迹组织中的ＣＬＳＶ。带毒愈伤组织较茎的显色反应敏感,显色反应时间仅为茎的一半（１５ｍｉｎ）。ＣＬＳＶ在愈伤组织中有两种分布情况：一是所有组织均有显色反应;二是呈不均匀分布。ＣＬＳＶ在茎组织中有三种分布情况：第一,除髓部外,表皮、皮层及维管系统中均有分布;第二,不均匀分布,ＣＬＳＶ集中分布于表度组织中,在皮层及韧皮部仅有少量分布;第三,“嵌合”分布,即同一种组织中部分组织带毒,部分为正常组织。     

THE CLIMATE CHANGE AND FORESTRY OF HEILONGJI ANG PROVINCE IN 1990''''S

INTRODUCTIONIntheworldoftoday,theglobalclimatechangeanditsinfluenceonecologyhavebe-comeaveryimportantproblem,towhichmanyscientists,governnentleadersandordinarypcoplepaycloseattentionI1-'].Inl979,theWorldClimateResearchProgram(WCP)waslaiddowninthefirstworldclimatemeeting.lnl99(),thesecondworldclimatemeetingwasconvcl1edinGencva,andalltl1eexpertsagreedthattheglobalwarmlngwillbeextremelyseriousdisasterthananynatUralcalamityever.Attl1eMectingof"WorldEnvironmentandDevelopment,"holdinBrazil…     

An investigation of uncertainty in field habitat mapping and the implications for detecting land cover change

Land cover data for landscape ecological studies are frequently obtained by field survey. In the United Kingdom, temporally separated field surveys have been used to identify the locations and magnitudes of recent changes in land cover. However, such map data contain errors which may seriously hinder the identification of land cover change and the extent and locations of rare landscape features. This paper investigates the extent of the differences between two sets of maps derived from field surveys within the Northumberland National Park in 1991 and 1992. The method used in each survey was the Phase 1 approach of the Nature Conservancy Council of Great Britain. Differences between maps were greatest for the land cover types with the smallest areas. Overall spatial correspondence between maps was found to be only 44.4%. A maximum of 14.4% of the total area surveyed was found to have undergone genuine land cover change. The remaining discrepancies, equivalent to 41.2% of the total survey area, were attributed primarily to differences of land cover interpretation between surveyors (classification error). Differences in boundary locations (positional error) were also noted, but were found to be a relatively minor source of error. The implications for the detection of land cover change and habitat mapping are discussed.