Frequency distribution of Echinococcus granulosus in dog populations in the Xinjiang Uygur Autonomous Region, China.

Age-prevalence and age-intensity data of Echinococcus granulosus in dog populations were collected in four counties in the Xinjiang Uygur Autonomous Region, People's Republic of China. The frequency distribution of the parasite per dog was adequately described by the negative binomial model, with parameter k being 0.0571. The mathematical model of the life cycle of E. granulosus constructed by Roberts et al. (1986--Parasitology, Vol. 92, pages 621-641) was used to estimate the epidemiologic parameters of E. granulosus in Xinjiang. This model showed that the prevailing infection pressure on dogs was 0.4560 infectious insults year-1 and the mean length of an infection was 1.4975 years. The effect of acquired immunity on the prevalence of E. granulosus in dogs was considered to be insignificant.     

庐山上的景天酸代谢植物

本文讨论庐山的景天酸代谢植物的分布、表现特征、代谢途径和生理生态。根据Kluge和Ting判断CAM植物的四条标准,庐山上的CAM植物分布于20多个科,其中有些种类具有重要的经济价值。根据植物对CO_2的固定途径不同,可把庐山上的CAM植物分为两种类型,一种是在个体发育所有阶段中始终保持CAM途径;另一种是随植物生长发育情况和环境条件的变化而改变CO_2固定途径。本文指出庐山上的CAM植物具有对干旱环境的适应性。     

20种植物提取物对马铃薯晚疫病菌的抗菌活性研究

在室内测试了20种植物提取物对马铃薯晚疫病菌的抑菌作用,结果表明9种植物提取物对 孢子囊萌发具有显著的抑制作用,6种植物提取物对孢子囊产生具有显著的抑制作用。其中Ts-86、 Ts-39、Ts-109和Ts-121四种提取物抑菌效果与化学药剂“Ridomil”3000倍达到同一显著水平,并对 其进行了进一步测试。结果表明,Ts-86对马铃薯晚疫病菌产孢及孢子囊萌发的抑制效果显著优于另 外3种提取物,与“Ridomil”3000倍达到同一显著水平。     

宁南山区不同施肥模式对苜蓿地上生物量的影响研究

宁南旱作农区是中国经济比较落后,生态环境十分恶劣的地区.西部大开发以来,该区苜蓿人工草地建设取得显著成就,如何在干旱条件下提高苜蓿产草量,成为该区生态经济农业研究的战略课题.根据不同的施肥模式试验,研究探讨了该地区苜蓿高产施肥技术措施,针对宁南地区的农业生态条件,提出适宜该区苜蓿高产施肥技术措施与施肥方案,常年降水不足400mm的宁南旱作农业区,在一定的施肥水平下仍然可以实现高效草地生态经济农业.生态经济农业(Ecological economy Agriculture):简言之就是"产业化的生态农业",是农业生态学、区域经济学和生态经济学理论在农业上的应用,不同于传统意义上的生态农业,是基于生态农业基础之上的新经济时代农业和农村经济的组织形式,其完善了生态农业理论界面的不足,将生态农业与农业产业化经营实现了有机结合,解决了农民组织化程度低、小农经济难以与大市场对接的问题.     

多头绦虫抗原特性的研究──多头绦虫节片抗原及原头节ES抗原的SDS-PAGE分析

为了探明多头绦虫成虫节片抗原及多头蚴原头节排泄分泌（ES）抗原的多肽组分，以供今后在免疫诊断与预防脑多头蚴病的应用，本试验应用SDS-PAGE首次分析了多头绦虫成虫节片抗原及多头蚴原头节ES抗原的多肽组分。应用12．5％凝胶的连续系统，垂直板型电泳，考马斯亮兰R－250染色的结果表明，成虫节片抗原共有16条多肽带，其分子量范围29～154kD，其中主带4条，分别为73、88、128、134kD，原头节ES抗原共6条多肽带，分子量范围33～132kD，其中主带2条，分别为33和108kD。本试验初步阐明多头绦虫成虫节片抗原和原头节ES抗原的多肽组分，为进一步研究多头绦虫抗原的特性奠定了基础。     

抗IBDV独特型抗体疫苗的制备与应用

应用提取纯化的抗ＩＢＤＶＩｇＧ免疫ＢＡＬＢ／ｃ小鼠，取其脾细胞与ＳＰ２／０细胞在ＰＥＧ作用下融合，应用ＥＬＩＳＡ法检测筛选，经有限稀释法克隆２次，获得２株（２Ｂ６株，５Ｆ４株）分泌抗ＩＢＤＶ独特型抗体的杂交瘤细胞株，其能诱生ＢＡＬＢ／ｃ小鼠产生高效价的含抗ＩＢＤＶ独特型抗体的腹水。用此独特型抗体分别与福氏完全佐剂、福氏不完全佐剂按１∶１比例乳化制备成抗ＩＢＤＶ独特型抗体疫苗，免疫接种ＳＰＦ鸡和普通京白公鸡，然后用ＩＢＤＶ野毒株经点眼和滴鼻方式攻毒，保护率分别为８／８、１４／１４，从而证实抗独特型抗体疫苗有潜在的研究和应用价值。     

樱桃番茄新品种京丹1号和京丹2号的选育

京丹1号、京丹2号是通过单株系统选择、组合试配及评比选育出的樱桃番茄新品种.其亲本品系分别是从日本商业品种和台湾品种四季红的分离后代中选出.京丹1号为无限生长类型,连续生长势强,结果习性好,单果质量8～12g,口感风味极佳,可溶性固形物7.5%以上；高抗ToMV,耐叶霉病.京丹2号是极早熟有限生长类型品种,播种后90d(天)开始收获,单果质量10～15g,可溶性固形物高于6. 0%,高抗ToMV.这两个品种已应用于北京、河北、山东和辽宁等地.     

梨授粉受精影响因素研究进展

梨树是异花授粉果树,授粉受精直接影响坐果率和收益.开展梨树授粉受精影响因素的研究,有助于选择与配置适宜的授粉树,也有助于梨树遗传育种的研究与品种改良.目前,已有许多关于梨树授粉受精影响因素的研究,现将这方面的研究进展综述如下.     

Mycobacterium szulgai infection in a captive population of African clawed frogs (Xenopus tropicalis).

A colony of captive Xenopus tropicalis became infected with Mycobacterium szulgai. Clinical signs, when observed, were lethargy, weight loss, and emaciation. Visceral granulomas were common findings at laparoscopy and necropsy. The diagnosis of mycobacteriosis was based on histologic appearance and Ziehl-Neelsen staining of tissues. The identification of M. szulgai organisms was based on comparison of the 16S rRNA gene sequence with several GenBank databases. There have been no reports of this mycobacterial species as the causative agent of naturally occurring disease in amphibians.     

Effects of dexamethasone on emesis in cats sedated with xylazine hydrochloride

OBJECTIVE: To determine antiemetic efficacy of prophylactic administration of dexamethasone and its influence on sedation in cats sedated with xylazine hydrochloride. ANIMALS: 6 healthy adult cats (3 males and 3 females). PROCEDURE: The prophylactic antiemetic effect of 4 doses of dexamethasone (1, 2, 4, and 8 mg/kg of body weight, IM) or saline (0.9% NaCl) solution (0.066 ml/kg, IM) administered 1 hour before administration of xylazine (0.66 mg/kg, IM) was evaluated. Cats initially were given saline treatment (day 0) and were given sequentially increasing doses of xylazine on days 7, 14, 21, and 28. After xylazine injection, all cats were observed for 30 minutes to allow assessment of frequency of emesis and time until onset of the first emetic episode.The influence of dexamethasone on xylazine-induced sedation in these cats also was evaluated. RESULTS: Prior treatment with 4 or 8 mg/kg of dexamethasone significantly reduced the frequency of emetic episodes and also significantly prolonged the time until onset of the first emetic episode after xylazine injection. Time until onset of the first emetic episode also was significantly prolonged for dexamethasone at a dose of 2 mg/kg. Time until onset of sedation after administration of xylazine was not altered by administration of dexamethasone. CONCLUSIONS AND CLINICAL RELEVANCE: Dexamethasone (4 or 8 mg/kg, IM) significantly decreased the frequency of emetic episodes induced by xylazine without compromising sedative effects in cats. Dexamethasone may be used prophylactically as an antiemetic in cats treated with xylazine.