优质蛋白玉米籽粒品质性状组间典型相关性研究

研究优质蛋白玉米籽粒品质性状组间典型相关性结果表明,2个半硬质胚乳奥帕克-2玉米群体(“中群14QPMC3”和“陕综5号QPMC0”)籽粒物理性状中硬质度、籽粒密度、百粒重与胚比、百粒体积呈负相关效应,营养品质中赖氨酸含量、蛋白质品质性状为其核心,籽粒密度(或硬质度)可作为蛋白质品质的间接选择指标;籽粒物理性状、蛋白质品质性状在赖氨酸产量构成中起决定性作用,全籽粒蛋白质品质与胚乳蛋白质品质紧密相关,而与胚蛋白质品质无关,高赖氨酸高油分育种相统一。     

Field trial of a staphylococcal mastitis vaccine in dairy herds: clinical, subclinical and microbiological assessments

Objective To assess the efficacy of a new staphylococcal mastitis vaccine under commercial dairying conditions.
Design A field trial involving 1819 cows and heifers conducted on seven dairy herds in Victoria. The trial was done 'blind'; approximately half the animals were vaccinated and the remainder were untreated controls.
Procedure The vaccine was given twice during the last 10 weeks of pregnancy. Effects of vaccination were assessed, during the ensuing lactation, on the basis of clinical and sub-clinical mastitis and microbiological investigations of the milk.
Results A total of 273 cases of clinical mastitis were recorded. Staphylococcus aureus was isolated from 112 of these, 45 cases in vaccinates and 67 cases in controls; the difference was not statistically significant. One herd was notable in having a high incidence of clinical staphylococcal mastitis. This herd accounted for 15.8% of the animals in the field trial but 54.5% of cases of clinical staphylococcal mastitis. For this herd, vaccinated animals had significantly lower incidence of clinical staphylococcal mastitis and prevalence of subclinical mastitis, relative to controls. An unexpected feature of the trial as a whole was the low incidence of clinical mastitis from which S aureus was isolated in pure culture (26.3% of cases) and the high incidence of clinical Streptococcus uberis mastitis (22.7% of cases).
Conclusions The trial showed that the vaccine was efficacious in reducing the incidence of clinical mastitis and prevalence of subclinical mastitis in a herd that had a serious staphylococcal mastitis problem.     

anwendung der „vergleichsmethode standort (vermost)” zur bewertung der erosionsgefährdungspotenziale als datenbasis für förderinstrumente am beispiel des landes Brandenburg: Application of the site comparison method (vermost) to assess the potential erosion risk as a basis to examine instruments of environmental policy – the example of Brandenburg

This paper presents a comparative method (VERMOST) to evaluate complex site conditions at the level of a federal state (Brandenburg) and at different areal units. The methodology uses primary site conditions and provides the possibility to objectively compare and judge different ecological questions. Objects with heterogeneous content are pooled in comparison groups. Considering the main site characteristics allows a goal-oriented allocation of subsidies. The use of VERMOST is demonstrated for the wind and water erosion risk assessment across different scales from a federal state down to a parcel of land. The ‘parcel’ aggregation-level proves to be useful to assess the erosion risk. Larger scales are less useful in the assessment of subsidies policy with regard to erosion risk. A moving-window-technique combined with VERMOST is demonstrated to be suitable for comparing and assessing regional aspects more objectively compared with data administratively linked.     

Segmentation of Color Image Based on Feature Divergence and Fuzzy Theory

In order to improve general adaptive capability of algorithm,the new color image segmentation algorithm based on feature divergence and fuzzy theory(FDCIS) is proposed.The algorithm introduces feature divergence and fuzzy dissimilarity function into calculation in order to measure the dissimilarity of feature vector,clusters data by means of feature divergence,and accomplishes the merge of image region.The experimental results demonstrate that the color image segmentation result of the proposed approach reduce calculation on large sample of color image,simply and effectively solve over-segmentation of color image,avoid the dependence of the algorithm on initial condition,and hold favorable consistency in terms of human perception.     

Epidemiology and management of a bovine brucellosis cluster in Northern Ireland

An epidemiological investigation was undertaken of 41 bovine brucellosis outbreaks that occurred within a 10-month period, in a region where eradication measures appeared to be succeeding. The primary outbreak comprised three herds with significant within-herd spread and a high probability of multiple abortions. Direct contact between cattle at pasture was the most likely means of between-herd transmission for most (71%) outbreaks, with an attack rate of 28.1% in herds immediately neighbouring the primary outbreak herds and 11.3% in the next concentric ring of farms. Resolution of the incident was attributed to a rapid response by the veterinary authorities, detailed epidemiological investigations, repeated, prolonged testing of contact herds and employment of parallel testing.     

Studies on the antigenic relationship between bovine subgroup 2 and conventional mammalian adenoviruses using immunofluorescence

In double immunodiffusion tests between a bovine subgroup 2 adenovirus (serotype 8) and other mammalian adenoviruses, no group-specific crossing was demonstrated.However, in cross-fluorescent antibody tests (FAT) between bovine subgroup 2 viruses (serotypes 5, 7 and 8) and conventional (non-subgroup 2) adenoviruses from several species (bovine adenovirus serotypes 1 and 2, ovine serotypes 1, 4 and 5, porcine serotype 1, and human serotypes 2 and 5) sharing of antigens was demonstrated. The FAT titres observed when rabbit antisera to conventional adenoviruses were used to stain bovine subgroup 2 viruses were, however, much lower than titres with other non-subgroup 2 viruses. The converse was also true. The crossing was also predominantly one-sided.The low level cross was confirmed using antisera to selected viruses prepared in chickens to exclude interference by possible natural adenovirus infections in the rabbits used to prepare the antisera in the initial experiments.     

Relationship Between Grain Yield and Yield Components in Super Hybrid Rice

Chinese super hybrid rice breeding project has developed many new varieties with great yield potential.It is controversial which yield component should be emphasized in super hybrid rice production.The present study was conducted to compare super hybrid rice with common hybrid and super inbred rice and analyze contributions of yield components to grain yield of super hybrid rice under experimental conditions,and evaluate relationships between grain yield and yield components of super hybrid rice in farmer's paddy fields.Field experiments were done in Changsha,Guidong,and Nanxian,Hunan Province,China,from 2007 to 2009.Eight super hybrid varieties,one common hybrid variety,and one super inbred variety were grown in each location and year.Rice production investigation was undertaken in high-yielding (Guidong),moderate-yielding (Nanxian),and low-yielding (Ningxiang) regions of Hunan Province,China,in 2009.Grain yield and yield components were measured in both the field experiments and rice production investigation.Super hybrid rice varieties outyielded common hybrid and super inbred varieties across three locations and years.Yield potential has been increased by 11.4％ in super hybrid rice varieties compared with common and super inbred varieties.The higher yield of super hybrid varieties was attributed to improvement in panicle size.Panicles per m2 had the highest positive contribution to grain yield with the exception under yield level of 10.0 to 12.0 t ha-1,and was positively related to grain yield in farmer's field at all of the high-,moderate-,and low-yielding regions.Our study suggests that panicle per m2 ought to be emphasized in super hybrid rice production.     

Analysis of obsidian from moho cay, belize: new evidence on classic maya trade routes

Trace element analysis of obsidian artifacts from Moho Cay, Belize, reveals that the obsidian derives primarily from the El Chayal outcrop in highland Guatemala and not from the Ixtepeque source. This is contrary to the widely accepted obsidian trade route model for Classic Maya civilization and suggests that Classic Maya obsidian trade was a more complex economic phenomenon than has been recognized.     

波尔山羊冻精解冻方法效果的分析

针对影响冻精配种受胎率的各种因素,总结分析了几年来在波尔山羊冻精配种中,采用不同解冻方法 解冻冻精对精子活力、存活时间、顶体完整率、死活染色率以及受胎率几方面的影响,结果表明：８０℃高温干解冻优于４０℃低温湿解冻;干解冻效果与温度呈正相关关系,以８０℃－０．４,存活时间１２￣１８ｈ;８０℃高温干解冻优于４０℃低浊湿解冻;干解冻效果与堇 正相关关系,以８０℃为最好,湿解冻与温度呈负相关关系,以４０℃