基于SWOT定量分析的济南市现代农业发展战略研究

调查分析了济南市现代农业发展的内部和外部环境因素,确定优势因素和劣势因素各9项、机会因素和挑战因素各5项;其次,设计问卷对28个影响因子进行了重要性调查,确定了各个因子的权重系数;最后,建立SWOT定量分析模型,对济南市现代农业发展的内外部环境进行了SWOT定量分析,用四维坐标法确定了济南市现代农业发展的战略类型,并结合济南市实际,提出发展济南市现代农业的战略措施。     

借鉴国外经验 助推宁夏沿黄经济区低碳农业发展

气候变暖对粮食生产、农产品安全及农业可持续发展提出了挑战,发展低碳农业是全球应对日益严峻气候变化的必然选择。文章总结了国外发展低碳农业的有效做法及经验,提出了助推宁夏沿黄经济区低碳农业发展的思路,如提高对低碳农业理念的认知水平、实施低碳化的激励政策工具、完善低碳农业技术规范和标准等。     

Evaluation of four commercial serum ELISAs for detection of Mycobacterium avium subsp. paratuberculosis infection in dairy cows

During the first 3 months of 2006, a study was performed on four dairy cattle herds with a history of clinical paratuberculosis, to evaluate different enzyme-linked immunosorbent assays (ELISAs). Serum samples obtained from 326 animals were analysed using four ELISAs to detect antibodies to Mycobacterium avium subsp. paratuberculosis (MAP). Kappa (kappa) concordance coefficients in pairwise comparisons of the ELISA outcomes ranged up to 0.22 (linear kappa) and 0.25 (quadratic kappa). When the borderline positives obtained were considered as negatives, kappa values remained low (kappa up to 0.19). Having performed the serological tests, faecal samples were then obtained from 55 animals (including all animals testing positive in two or more ELISAs) from the same herds. Faecal culture and faecal polymerase chain reaction (PCR) for the detection of MAP were negative in all cases. The results indicate that neither the currently available serum ELISAs nor faecal culture and PCR are effective for the early detection of MAP in dairy cattle.     

Penalized regression techniques for modeling relationships between metabolites and tomato taste attributes

The search for models which link tomato taste attributes to their metabolic profiling, is a main challenge within the breeding programs that aim to enhance tomato flavor. In this paper, we compared such models calculated by the traditional statistical approach, stepwise regression, with models obtained by the new generation of regression techniques, known as penalized regression or regularization methods. In addition, for penalized regression, different scenarios and various model selection criteria were discussed to conclude that classical crossvalidation, selects models with many superfluous variables whereas model selection criteria such as Bayesian information criterion, seem to be more suitable, when the goal is to find parsimonious models, to explain tomato taste attributes based on metabolic information. An exhaustive comparison of the discussed methodology was done for six sensory traits, showing that the most important covariates were identified by the stepwise regression as well as by some of the penalized regression methods, despite the general disagreement on the size of the regression coefficients between them. In particular, for stepwise regression the coefficients are inflated due to their high variance which is not the case with penalized regression, showing that this new methodology, can be an alternative to obtain more accurate models.     

3＇ Noncoding Region Construction of GHR Gene-luciferase Report Vector and Valuation

To analyze miR-139 target sites in 3＇ UTR of GHR gene in dairy cow mammary gland, a GHR 3＇ UTR- luciferase reporter vector was constructed and the effect of miRNA on its activity was evaluated in dairy...     

四个二斑叶螨地理种群卵对10种杀螨剂的敏感性差异

为了明确二斑叶螨卵对现有杀螨剂的敏感性现状,采用棉苗浸渍法测定了4个二斑叶螨地理种群卵对10种常用杀螨剂的敏感性。结果表明,昌乐和寿光蔬菜大棚内二斑叶螨卵的敏感性明显低于郑州和沂源种群。其中,4个抗性种群对哒螨灵的敏感性均较低,敏感系数从高到低依次为:昌乐(216.02倍)、郑州(112.45倍)、沂源(53.56倍)、寿光(12.74倍)。唑螨酯和螺螨酯对卵的毒力均较高,是防治二斑叶螨卵较好的药剂。     

中国疫区内苹果蠹蛾微卫星位点的扩增稳定性及遗传多样性

为揭示欧洲苹果蠹蛾微卫星位点在中国苹果蠹蛾群体遗传学研究中的有效性,以12对微卫星引物对采自中国主要疫区新疆、甘肃、黑龙江的8个苹果蠹蛾地理种群的120头个体在各位点的遗传多样性及扩增稳定性进行研究。所选取的12个微卫星位点中,有8个能够稳定扩增,各位点在大多数种群中均显示偏离哈迪-温伯格平衡,各位点上的平均等位基因数量为3.750～12.500,平均观察杂合度Ho为0.025～0.783,平均期望杂合度He为0.284～0.892。位点Cp2.P和Cp4.56分别具有较低的观察杂合度(0.109、0.025)和较高的近交系数Fis(0.806、0.954),说明这2个位点上的杂合子非常缺乏,其余6个位点均具有较高的杂合度水平和等位基因数量,适用于中国疫区内苹果蠹蛾微卫星分子标记研究。     

渠道流量损失及水利用系数公式的探讨

针对现行渠道设计中的流量损失和水的利用系数公式的不足之处,利用高等数学中积分学方法,推导出新的公式,并用中等透水性(A=1.9,m=0.40)的渠道的实例加以验证.结果表明比传统公式计算的结果精确,可供灌溉管理的水利工作者参考.     

Effect of total alkaloid ofPeganum harmala L. in the treatment of experimental haemosporidian infections in cattle

Cattle experimentally infected withBabesia bigemina orTheileria sergenti or mixed infestations of the two parasites were treated with Total Alkaloid ofPeganum harmala L. The results showed that treatment was effective againstB. bigemina infection, had a marked effect on the course of infection withT. sergenti and some effect on the course of the mixed infection.