Preliminary studies on the effectiveness of the novel pulicide, spinosad, for the treatment and control of fleas on dogs

Spinosad is a novel mode-of-action insecticide produced from a family of natural products derived from fermentation of the actinomycete, Saccharopolyspora spinosa. Separate studies were undertaken to determine the minimum effective dose of spinosad given orally for the treatment of experimentally induced flea infestations (Ctenocephalides felis) on dogs, and to assess any potential impacts of feeding canned or dry food at the time of dosing. Both were randomized block (blocked by gender and pre-treatment flea counts), blinded parallel-arm studies, with dogs selected on health and ability to maintain pre-treatment flea populations. For dose selection, 48 dogs were allocated among six groups (8 dogs/group; 4 males, 4 females): placebo-treated negative control, spinosad in gelatin capsules at 15, 20, 30 and 40 mg/kg administered per os; and topical imidacloprid (10 mg/kg) as a positive control. Placebo and spinosad treatments were administered on Days 0, 30 and 60, imidacloprid only on Day 0. In a second study to assess the impact of food type at the time of dosing, three groups were formed: placebo-treated control (8 dogs; 4 males, 4 females), spinosad (30 mg/kg) administered with canned food (8 male dogs, 8 females); and spinosad (30 mg/kg) with dry food (8 males, 8 females). Treatments were administered on Days 0 and 30. To assess post-treatment persistent efficacy, flea infestations were repeated at regular post-treatment intervals, beginning on Day 5 through Day 89 in the dose selection study and Day 58 in the impact of food type and dosing study. Flea counts were performed 48 h post-infestation by study personnel who were blinded to treatments. In the dose selection study, compared to geometric mean live flea counts in the control group, each spinosad dose was highly effective (99.8–100%) at 7, 14 and 21 days after treatment. Only the 30 and 40 mg/kg doses maintained high efficacy (97.2–100%) until 30 days after treatment, with no difference between the two. Imidacloprid was highly effective at Day 30, with significant difference only from the 15 mg/kg spinosad group. Because there was no significant difference between the higher spinosad rates, 30 mg/kg was selected as the optimal minimum effective dose. In the second study, spinosad was highly effective at all post-treatment flea counts (98–100%). Taken together, these studies demonstrate that repeated monthly oral treatments with spinosad at 30 mg/kg provide sustained control of C. felis on dogs. There were no treatment-related adverse events in either study, indicating that spinosad has potential to be used monthly as a safe and effective flea adulticide, providing sustained activity that matches that of currently used topical products.     

河南省新发杨树黄叶病害的发生特性研究

对河南省2005年以来新发生杨树黄叶病害的发生特性进行了研究。结果表明,2008年病害危害继续扩大,新发病地块出现50处,但老的发生区没有大面积扩散,枯死数量所占前年总病树的百分比从2007年的1%下降到了0.6%。黄叶病杨树存在侧芽萌发及顶芽小叶现象,但不属于植物病理学上的丛枝。病害在春秋两季发病明显,实验证明病害与越冬关系不大,7月份有隐症现象,该隐症为高温隐症。加强水肥管理及间伐对缓解症状有一定作用,但是不能彻底治愈,病因可能与苗木的来源有一定关系。病害的发生在立地条件上没有明显规律,养殖小区和菜地内的杨树明显发病较早、较重。未发现明显抗病的杨树品种,法桐等其它近10种树种亦有类似症状。     

Detection of Salmonella in Chicken Embryos in a Breeding Poultry Field of Chengdu

In a poultry farm of Chengdu city,Sichuan province,isolation,identification and drug sensitivity test of Salmonella were conducted from 156 dead embryos.In this experiment,we used Salmonella chromogenic medium,biochemical identification of enterobacteriaceae,trisaccharide iron experiment,Salmonella polyvalent serum and 16S rRNA PCR to identify suspected strains,PCR identification of isolated Salmonella were conducted with 6 kinds of virulence genes.The results concluded that Salmonella separation rate was 15.4%(24/156),including Salmonella typhi accounted for 58.3%(14/24); Detection rates of fimY,invA and mgtC virulence genes were all 100%;The isolated Salmonella were resistant to most clinical drugs to Salmonella.     

船式车辆船体起步阻力理论及试验研究

分析了船体车辆的行驶特点及船体起步阻力的形成机理，建立了船体起步阻力的预测模型，并对此模型进行了室内土槽试验验证，结果表明，试验结果与预测计算基本吻合。     

一种改进的压燃式内燃机理论循环

提出了一种有别于传统内燃机理论循环的改进型压燃式内燃机理论循环，并分析了实现这一循环的可能性，理论分析及试验表明，改进型理论循环不仅可以提高内燃机的循环热效率、动力性能，改善经济性能，而且可以降低柴油机的烟度值，改善排放性能，减轻柴油机的工作粗爆性，它适应了当前世界内燃机向节能、净化、环保及强化型发动机发展的趋势。     

水稻籽粒材料力学特性研究

本文从水稻籽粒抗压、抗剪、抗冲击试验仪器及试验方法的研究着手,对我国水稻各品系的籽粒,在不同的工况下进行了大容量的试验测定,并运用统计科学的方法进行数据处理,从而得出早籼稻糯稻、晚籼稻及粳稻三大类籽粒的材料力学特性相关数学模型。确立了该特性参数的敏感区及在不同含水率工况下其特性参数的应选数值和范围。     

高产节水冬小麦新品种衡7228的选育

冬小麦新品种衡7228是由河北省农林科学院旱作农业研究所选育的。选育过程中采用了水旱交替选择法、异地鉴定法等先进方法。选出的衡7228具有高产、节水、抗逆的突出特点,是非常适合黄淮北片冬麦区的一个优良品种。     

产品生命周期的模糊识别模型

将产品销售量、利润率和市场占有率作为研究指标，构建了产品生命周期的模糊识别模型。实例分析结果表明，该模型是判断产品所处生命周期阶段的一种有效的量化方法。     

我国控释肥料生产应用现状与发展对策

介绍了我国控释肥料发展的历史及生产应用现状,指出其在生产应用中存在的价位太高、控释效果不明显和不稳定及政府对控释肥料的重视程度不够等问题,并提出了发展控释肥料的对策。     

中国畜产品生产分析及预测

从中国畜产品生产现状出发,分析了1978年以来中国畜产品生产三个阶段特点以及影响畜产品生产的主要因素,并根据以上分析,预计了2010年、2015年、2020年中国畜产品生产量和人均占有量.认为中国畜产品产量在稳步增加的同时,结构调整将进一步优化,稳定发展生猪和禽蛋生产,加快发展肉牛、肉羊和肉鸡生产,突出发展奶类生产.