温度和湿度对南方根结线虫存活的影响

在实验室条件下,测试了不同温度处理对离体南方根结线虫存活的影响,结果表明,在25、30、35℃和40℃下,杀死90%以上离体南方根结线虫分别需要30d(100%)、26d(96.6%)、24d(94.1%)和9d(99.6%),而45、50℃下则需要15min和2.3min。同时测试了不同温湿度处理对土壤中南方根结线虫存活的影响,结果表明,25、30℃是土壤中根结线虫的适宜温度,当土壤含水量为14%时,40d死亡率分别为91.1%、90.4%;35℃线虫处于抑制状态,40d死亡率为85.3%;而线虫对40℃以上的高温敏感,随着处理温度升高,杀死线虫所需时间缩短。根结线虫在不同温湿度下的死亡情况不同,土壤温度为25～35℃,土壤含水量为6%是线虫的适宜湿度;土壤温度达到40℃且含水量为6%和14%时,杀死100%根结线虫仅需4d,不利于其存活;而50℃的高温和含水量达18%的高湿更不利于其存活。     

Aberrant extradural spinal migration of Spirocerca lupi: four dogs

Spirocerca lupi is a nematode mainly affecting dogs but has been found in other animals, particularly carnivores. Anatomical areas of typical and aberrant migration vary. This report describes four cases of Spirocerca lupi causing neurological symptoms, similar to thoracolumbar disc syndrome, as a result of aberrant migration of the nematode into the spinal canal. In two of the cases, the nematode could be demonstrated intraoperatively. The third was discovered on post-mortem examination, while the fourth case displayed compelling evidence of Spirocerca lupi involvement. Surgical removal of the Spirocerca lupi nematode would be the treatment of choice in cases of spinal migration, with therapeutic and preventive treatment with doramectin instituted to treat remote sites and prevent re-infection. In areas endemic for spirocercosis, Spirocerca lupi should be considered as an important differential diagnosis in cases that are presented with clinical signs suggestive of a spinal cord lesion.     

保护地番茄新品种中杂11号的选育

中杂11号番茄是从欧洲、日本等地引进优良资源材料，经多代复合杂交新育成的适合保护地栽培的中熟杂种一代。抗ToMV、枯萎病、叶霉病。大果型，果实粉红色，果形整齐，耐贮运，商品率高。丰产性好，单位面积产量超过中杂9号。     

生态系统视角下农村失独家庭的困境应对策略研究

农村失独父母是我国计划生育政策实施以来产生的一个特殊弱势群体.由于农村社会经济发展的特殊性,处于失独困境的家庭亟待政府和社会的更多关注和支持.农村失独家庭面临家庭关系紧张、精神承受重压、经济水平落后、生活缺乏照顾、养老医疗困顿、人际关系贫瘠等难题.为了化解上述难题,必须尽可能发挥政府和社会的保障支持功能.基于生态系统理...     

川南常羽乌骨鸡肤色的遗传研究

通过对川南常羽乌骨鸡三种羽色系的纯繁、杂交以及与三个浅肤品种的杂交，初步揭示了川南常羽乌骨鸡肤色的遗传现象。结果表明，所用乌骨鸡的肤色主要受遗传控制，存在杂合类型，黑羽系和麻羽系的肤色遗传较为稳定。乌肤性状终生不变，且与趾色、肉骨及肉膜色高度相关。乌肤公鸡与不同浅肤母鸡的杂交后代可表现出较高的不同的乌肤比例，表明适当引入浅肤血缘尚可保持乌骨鸡的乌色性状。     

The block method of vaccination against heartwater

A critical evaluation is made of reports in the literature on the block method of vaccination and the relevant factors that play a role in the immunization against heartwater are also discussed. The most important of these is the fact that in heartwater immunogenicity parallels pathogenicity. It is shown that the more severe the reaction of the host to the immunizing infection, the stronger its immunity to subsequent challenge. The importance of this principle in the block method is emphasized. Other factors that play a role are the average incubation periods recorded in the different domestic ruminants after experimental infection and differences in age and breed susceptibility. The survival rate of experimentally infected Bonsmara cattle and Merino sheep that were treated on different days of the febrile reaction also serve as a guideline to determine the day after infection on which block treatment can be applied. The danger of a fatal recrudescent infection if block treatment is given too early, necessitating additional treatment and close observation, is indicated. In conclusion, recommendations on the day of block treatment are made for each domestic ruminant species. It is emphasized that the other methods of immunization of large groups of animals, such as treatment only after the commencement of the febrile reaction determined by the daily recording of early morning temperatures, or the prolonged prophylactic chemotherapy of susceptible stock exposed to heavy tick challenge, are preferable to the block method. The block method does, however, find application in certain instances where these procedures are impractical or inappropriate.     

六个油菜物种的染色体组型分析

对油菜的三个基本种和三个复合种体细胞染色体的核型研究表明:六个种特别是三个基本种的染色体形态是大致相似的;但随体的形态和数目存在明显的多样性和杂合性;同时,三个复合种中随体数目是其基本种亲本之和。     

Adult Amblyomma hebraeum burdens and heartwater endemic stability in cattle.

Several conclusions of importance to studies on the epidemiology of heartwater were drawn from an investigation in which the numbers of adult Amblyomma hebraeum ticks, to which a closed herd of Hereford cattle were exposed over a period of 6 1/2 years, were manipulated. With a tick Cowdria ruminantium infection rate of 3-5%, an endemically stable situation was created by dipping the herd only when an average of 10 adult male and female A. hebraeum ticks were counted on 10 animals. When the average was increased to 15 during the calving period, 97% of calves acquired a tick-mediated immunity at the age of 6 months. Because only adult ticks confined to the hindquarters are counted, this procedure is recommended as a feasible and practical guideline to stock owners wishing to determine a dipping programme that would ensure endemic stability. The indirect fluorescent antibody test gave a true reflection of the infection rate through ticks in calves 3-6 months old, but not in older animals that had been re-infected more than once. This is because on one hand antibody may persist for 2 years after withdrawal from tick exposure and on the other the artificial re-infection of cattle with a tick acquired immunity is not always followed by a rise in antibody titres and may even result in seronegativity. Four cows infected and re-infected through ticks, remained immune to challenge for 2 years after withdrawal from tick exposure. Within the confines of one farm 3 isolates of C. ruminantium that differed in pathogenicity and immunogenicity were recovered from ticks. One of these isolates was almost non-pathogenic to cattle.     

Effect of chlorogenic acid on intestinal inflammation,antioxidant status,and microbial community of young hens challenged with acute heat stress

Heat stress in poultry is deleterious to productive performance. Chlorogenic acid (CGA) exerts antibacterial, anti-inflammatory, and antioxidant properties. This study was conducted to evaluate the effects of dietary supplemental CGA on the intestinal health and cecal microbiota composition of young hens challenged with acute heat stress. 100-day-old Hy-line brown pullets were randomly divided into four groups. The control group (C) and heat stress group (HS) received a basal diet. HS + CGA₃₀₀ group and HS + CGA₆₀₀ group received a basal diet supplemented with 300- and 600-mg/kg CGA, respectively, for 2 weeks before heat stress exposure. Pullets of HS, HS + CGA₃₀₀, and HS + CGA₆₀₀ group were exposed to 38°C for 4 h while the control group was maintained at 25°C. In this study, dietary CGA supplementation had effect on mitigate the decreased T-AOC and T-SOD activities and the increasing of IL-1β and TNFα induced by acute heat stress. Dietary supplementation with 600 mg/kg CGA had better effect on increasing the relative abundance of beneficial bacterial genera, such as Rikenellaceae RC9_gut_group, Ruminococcaceae UCG-005, and Christensenellaceae R-7_group, and deceasing bacteria genera involved in inflammation, such as Sutterella species. Therefore, CGA can ameliorate acute heat stress damage through suppressing inflammation and improved antioxidant capacity and cecal microbiota composition.     

温度影响下斑潜蝇种间竞争取代的分子机制研究进展

斑潜蝇是一类为害园艺蔬菜作物的世界性害虫,也是我国重要的外来有害生物。斑潜蝇种类繁多,不断向世界各地入侵扩散,在其扩散过程中种间竞争取代频繁。斑潜蝇种间竞争取代机制复杂,影响种间竞争取代的因子很多,其中温度是影响斑潜蝇种间竞争取代的重要因子。该文首先以温度影响下斑潜蝇种间竞争生态学机制为切入点,分别从关键胁迫耐受性基因——热激蛋白(heat shock protein,Hsp)基因的表达、Hsp基因非编码区的特征和转录组比较分析3个层面对近缘斑潜蝇竞争取代分子机制进行总结与探讨,并从胁迫耐受性基因类型、分子生物学研究方法及种间竞争其他因子等方面对斑潜蝇种间竞争取代未来的研究方向进行了展望。