Antibody response to crustacean ectoparasites in rainbow trout, Oncorhynchus mykiss (Walbaum), immunized with Argulus foliaceus L. antigen extract

Abstract. A humoral antibody response was demonstrated by ELISA in rainbow trout immunized intraperitoneally with extracts from the branchiuran ectoparasite Argulus foliaceus. A similar immunization protocol produced a higher titre response in a rabbit. Both trout and rabbit identified several antigenic components on immunoblots. ELISA and immunoblotting indicated that rainbow trout and rabbit anti-A. foliaceus sera identified components from the parasitic copepods Lepeophtheirus salmonis and Caligus elongatus.     

Effects of dietary molybdenum on nematode and host during Haemonchus contortus infection in lambs.

The addition of molybdenum (0.05 mmol kg-1 dry-matter) to the diet of lambs given a trickle infection of Haemonchus contortus larvae (500 third stage larvae d-1 over six weeks) reduced mean faecal egg counts (epg) from 3952 to 2312 +/- 402 by 32 days (P less than 0.02) and greatly reduced the mean number of worms recovered from the abomasum 14 days after infection ceased (907 compared with 4167: P less than 0.01). Infection reduced haemoglobin concentrations less in lambs given molybdenum although the difference was small relative to the reduction in worm burden. Lambs not given molybdenum had low intraepithelial mast cell counts in the abomasal mucosa and less abomasal hypertrophy than expected from abomasal parasitism. Molybdenum did not consistently reduce the copper status of the host or the parasite. Previous exposure to molybdenum greatly reduced protein but not proteinase activity in, or secreted by, adult worms cultured for eight hours. It is suggested that molybdenum either increased the inflammatory response which preceded worm rejection or that it indirectly enhanced that reaction by reducing the effectiveness of copper-dependent, anti-inflammatory enzymes in the gastrointestinal mucosa.     

低、无毒农药防治花灌木主要刺吸式口器害虫

在查清天津市园林主要花灌木刺吸口器害虫桃粉蚜、绣线菊蚜、棉蚜和山楂红蜘蛛发生消长规律的基础上 ,确定了防治适期和结合点 ,筛选出 10 %吡虫啉、绿灵、蚧螨灵、 1. 8%齐螨素和花保5种低、无毒药剂 ,防效均达到 90 %以上。查出天敌 13种 ,并对优势种作了取食量调查     

Evaluation of a monoclonal blocking ELISA and IHA for antibodies to Mycoplasma hyopneumoniae in SPF-pig herds.

A monoclonal blocking enzyme-linked immunosorbent assay (ELISA) and an indirect haemagglutination assay (IHA) were applied to serum samples from 124 specific pathogen-free (SPF) breeding and multiplying herds, which participate in the routine serological surveillance of the Danish SPF programme. Clinical and pathological observations of the herds and microbiological culturing of Mycoplasma hyopneumoniae were used to calculate herd sensitivity, herd specificity and herd predictive values for the two serological assays. The ELISA was superior to the IHA in herd sensitivity and herd specificity, with values of 93 per cent and 96 per cent, respectively, for the ELISA, and 61 per cent and 92 per cent for the IHA. During the six month period of evaluation 2.5 per cent of the herds were infected with M hyopneumoniae each month. At this level the IHA was found to have a positive herd predictive value of 16 per cent, compared with 39 per cent for the ELISA. The negative herd-predictive value on the same level was 99.8 per cent for the ELISA and 98.9 per cent for the IHA. If the assays were applied to a group of herds with a herd prevalence of M hyopneumoniae infection of 30 per cent (as is the case with the production herds in the Danish SPF programme) the predictive value of a positive herd diagnosis would be 91 per cent for the ELISA and 76 per cent for the IHA, and the predictive value of a negative herd diagnosis would be 97 per cent with the ELISA and 85 per cent with the IHA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Surgical treatment of dorsal cortical fractures of the third metacarpal bone in thoroughbred racehorses: 53 cases (1985-1989).

Between January 1985 and May 1989, 53 Thoroughbred horses (mean age 3.2 years) were surgically treated for dorsal cortical fractures of the third metacarpal bone (MC III). All horses were treated with cortical drilling through the fracture line (osteostixis). Diagnosis of the fractures was confirmed by xeroradiography. Lifetime racing records were obtained for all horses. Forty-seven horses returned to racing after surgery (89%). The mean time between surgery and the first race was 6.8 months. Horses had a mean of 10.9 starts before surgery and 16.1 starts after surgery. The mean earnings per start before surgery was $6,459 and after surgery was $5,685. Of the 47 horses that raced after surgery, 70% raced at the same class or improved. Complications related to surgery were seen in 10 horses. Two horses had a second fracture of MC III at the same site, and were again treated by osteostixis, after which both horses returned to competition. Fractured drill bits were left in the MC III of 4 horses. One of these horses had catastrophic failure of MC III. Two horses developed subcutaneous infections and 2 horses had catastrophic failure of MC III in the surgically treated limb. Osteostixis appears to be an effective treatment for returning horses affected with dorsal cortical fractures to racing.     

高山地区美国黑树莓的栽培和管理

论述了美国黑树莓在泰顺高山地区引种栽培时应注意的引种栽培时间和栽培方法以及生产中应注意的搭架牵引、整形修剪、水肥管理等技术,最后分析讨论了其开发现状和今后的发展前景.     

兵团农机产业化的若干思考

农机产业化是社会分工细化、生产专业化深化的必然产物，其实质是传统农业转变为现代产业的过程。日前，兵团农机产业化进程中存在着一些问题。为此，结合兵团实际，提出了推进农机产业化发展的基本思路。     

论外来词

随着科学技术的迅猛发展以及我国对外交往的日益频繁,外来词（借词）特别是英语词汇越来越多地渗透到我们的日常生活中.不少人对此表现出了很深的忧虑：这会不会破坏汉语文字的纯洁性？本文主要对外来词所涉及的内容、存在的依据、借用的形式以及应用等方面进行探讨,并着重指出外来词不会影响汉语的纯洁性;相反,外来词的借入会不断地丰富我们的语言宝库,因此人们应该以一种更开放的心态来吸纳外来词.     

导入AGPase基因的转基因可育水稻及其经济性状的研究

以农杆菌介导法将淀粉合成关键酶AGPase(腺嘌呤二磷酸葡萄糖焦磷酸化酶）基因导入云南地方优质水稻合系35，38，39，41，42中，获得了大量的可育转基因植株。PCR扩增检测，外源基因已稳定整合进水稻基因组中。大量的农艺性状及淀粉含量研究表明，转基因水稻种子的千粒重比对照明显提高，但总淀粉含量没有显著变化。     

树木挥发物对植食性昆虫的诱导抗性

树木挥发物质对植食性昆虫取食，产卵所产生的诱导抗性是树木与昆虫的长期协同进化过程中的必然结果，树木与植食性昆虫之间发展了一套互相调节，自身开拓资源，产生生存对策的复杂相互关系，本文着重阐明了树木与植食性昆虫的互相策略，诱导抗性的生物化学基础以及诱导抗性在调节植食性昆虫种群中的重要性。