鸭大肠杆菌病流行病学与病原特性研究

对浙江等地鸭大肠杆菌病流行病学进行调查，并研究其发病特点，分离鉴定出致病性大肠杆菌26株；已对其中20株菌株进行血清型鉴定，主要为078，占70%（14/20），其次是O1，占15%（3/20）；人工感染试验表明，80%（8/10）菌株毒力强，皮下、肌肉、足蹼3种途径均易复制该病；病理组织学检查肝、肺、脾等，表现急性炎症，出血等病变；药敏试验表明，不同菌株对药物敏感性差异较大，除对鸭菌消、卡那霉素等高敏外，对多数常用抗菌药已耐药，最后就该病的防治提出了对策。     

Flow cytometric analysis of T cell response in mice infected with Cowdria ruminantium.

A 3-fold increase in the numbers of Lyt-2+ T cells in the circulating blood of mice infected and re-infected with the Welgevonden stock of Cowdria ruminantium, as determined by flow cytometry, is supportive evidence that immunity in heartwater is cell-mediated. The rise in Lyt-2+ cells only after re-infection of the mice is further evidence that the development of immunity in heartwater is dependent on the unhindered and adequate replication of C. ruminantium.     

An improved ferritin assay for canine sera

An improved serum ferritin assay for canine serum has been developed. It uses two monoclonal antibodies in a sandwich arrangement. Serum ferritin can be determined on undiluted canine sera with this assay. The recovery of ferritin added to canine serum ranged from 98 to 106%, the within-assay coefficient of variability was 3.3 to 4.5%, and the assay-to-assay variability was 9.8 to 10.2%. Serum ferritin from 61 apparently healthy dogs had a geometric mean of 252 ng/ml, with a range of 80 ng/ml to 800 ng/ml.     

The relationship between the pharmacokinetics of intravenous cismethrin and bioresmethrin and their mammalian toxicity

The distribution and excretion of [¹⁴C]alcohol-labeled cismethrin and bioresmethrin was determined after intravenous administration to rats. Initially the label distribution of both isomers was similar, but differences occurred at later times mainly due to the retention of 5-benzyl-3-furylcarboxylic acid, a metabolite of bioresmethrin, in high concentration in the blood. Retention of this metabolite accounted for the slower excretion of bioresmethrin label compared to cismethrin. After administration of either isomer, parent pyrethroid was rapidly cleared from the blood and liver, and both isomers rapidly entered the central nervous system reaching peak concentrations within 2–5 min. Brain cismethrin concentrations exceeding 3.5 nmol/g were associated only with animals showing tremors. These levels of cismethrin are maintained for up to 30 min but bioresmethrin was depleted more rapidly possibly due to brain metabolism. It is concluded that the low toxicity of bioresmethrin is possibly due to the inability of this isomer to interact with the site of action in the central nervous system and not, as previously suggested, primarily because of more rapid metabolism in the liver.     

高寒牧区牧鸡鸭治蝗效果试验

在青海湖北岸高寒牧区利用人工饲养的鸡鸭进行放牧防治草原蝗虫。结果表明,在60d的防治期内,牧鸡鸭平均灭治效果达91.4%,为人工利用天敌治虫技术在高寒牧区的应用提供了依据。     

鸭疫里氏杆菌形态特征的电镜观察

自鸭传染性浆膜炎的病死鸭中分离鉴定的鸭疫里氏杆菌(RA)Ⅰ、Ⅱ型两个菌株，用负染法和超薄切片法制备样品，于透射电镜下进行观察。结果观察到约占1／3的RA具有特殊的形态结构：在细菌的顶端或侧面有1～2个与菌体相连的芽状赘生物，有的也能从菌体上脱落下来。它在超薄切片中的大小约为菌体的1／3～1／5，能观察到其内部也具有类似菌体内部的结构。且具有类似菌体的“细胞壁”，类似于核体部分的结构位于“细胞壁”的一侧。而用相同的方法制作的鸭大肠杆菌(E．cozi)对照样品，却见不到这种特殊的形态结构。说明这种形态特征可能是RA特有的。     

基于GIS的丹东地区柞蚕农业气候区划

根据当地柞蚕实际生产与气象条件的关系,确定了柞蚕生产的农业气候区划指标.运用丹东地区1:250000地形数据和丹东及周边地区气象站30年的气候资料,建立区划指标小网格推算模型,应用GIS技术对丹东地区柞蚕生产进行气候区划,将该区划分为气候最适宜区、气候适宜区、气候次适宜区和气候不适宜区,为丹东柞蚕生产的合理布局和发展提供参考依据.     

中早熟辣椒新品种‘农大7号’

‘农大7号’辣椒是以HP1016为母本,Y0931为父本杂交选育而成。植株长势强,平均株高78.7 cm,中早熟。果实羊角形,青熟果黄绿色,果面光滑,果肉厚,平均单果质量80 g,平均单株结果数26.8个。果实维生素C含量0.56 mg·g^-1,粗纤维含量1.15%。抗疫病、炭疽病等。适宜河南全省各地(含烟区)早春保护地种植。