Co‐infection with Cucumber vein yellowing virus and Cucurbit yellow stunting disorder virus leading to synergism in cucumber

Symptom expression and levels of the ipomovirus Cucumber vein yellowing virus (CVYV) and the crinivirus Cucurbit yellow stunting disorder virus (CYSDV) were compared in greenhouse cucumbers in single and mixed infections. Results were contrasted with those obtained for plants infected with the potyvirus Zucchini yellow mosaic virus (ZYMV) in single and in mixed infections with either CVYV or CYSDV. Cucumber showed leaf symptoms of each co‐infecting virus, except for the combination of CYSDV with ZYMV, where the typical CYSDV‐like symptoms of interveinal leaf yellowing were inconspicuous or absent. The progression of CVYV as quantified by real‐time RT‐PCR was similar in plants with single infections and in mixed infection with CYSDV between 15 and 60 days post‐inoculation (dpi). However, CYSDV was detected at significantly enhanced levels in plants when co‐infected with CVYV but not when co‐infected with ZYMV. In the latter case, ZYMV levels were reduced when compared with single infections. During mixed infections of ZYMV and CVYV, the titre levels of the ipomovirus were significantly lower when compared with single infections. Cucumber had reduced plant height, internode length, dry weight and fruit yield, positively correlated with the titre levels of CVYV and not of CYSDV during mixed infections. It is concluded that co‐infections with CVYV enhance the titre of CYSDV, which could have epidemiological significance.     

内蒙古呼包鄂区域协调评价

以内蒙古呼和浩特市、包头市、鄂尔多斯市为研究对象,采用了层次分析法从经济水平、社会水平、资源环境3个方面构建指标体系,建立研究模型,对2010年呼和浩特市、包头市、鄂尔多斯市的区域系统发展程度进行了分析评价.     

种植密度对东北特早熟棉区棉花生物量和氮素累积的影响

 以辽棉19号（生育期125 d）和新棉33B（生育期135 d）2个生育期差异较大的品种为材料,于2007－2008年在东北特早熟棉区（辽宁辽阳,41°26' N,123°14' E）设置棉花种植密度试验（7.50万、9.75万、12.00 万株·hm^-2）,研究不同棉花群体生物量与氮素动态累积特征的差异及其与产量品质形成的关系。结果表明,棉花群体生物量和氮素累积动态随生育进程的变化符合“S”型曲线,棉花群体生物量和氮素存在异速累积现象,氮素累积快速起始期及终止期均较生物量累积提前10 d左右。2品种均以9.75 万株·hm^-2密度下棉花生物量、氮素动态累积过程最为优化,皮棉产量最高,纤维品质最优;密度过高尽管群体生物量、氮素累积量较高,但经济产量下降。     

心痛方对心肌缺血模型大鼠MPO 活性 及PS 表达的干预作用

目的探讨心痛方对心肌缺血大鼠模型心肌梗死面积及髓过氧化物酶（MPO）、P 选择素（PS）的干预作 用。方法80 只清洁级SD 大鼠,随机分成假手术组、模型组、心痛方组、欣康组,采用结扎法造成心肌缺血模型,NBT 染色法测心肌梗死面积,比色法检测MPO 活性,免疫组化法检测PS 的表达。结果1.模型组、心痛方组、欣康组心肌梗 死面积、MPO 活性及PS 表达均显著高于假手术组,差异有统计学意义（P<0.01）;2.心肌梗死面积比较,心痛方组、欣康 组分别小于模型组（P<0.05）,差异均有统计学意义;3.MPO 活性比较,心痛方组、欣康组分别低于模型组（P<0.05）,而 心痛方组低于欣康组（P<0.05）,差异均有统计学意义;4.PS 表达比较,心痛方组、欣康组分别低于模型组（P<0.05）,差 异均有统计学意义。结论心痛方能缩小心肌梗死面积,抑制缺血心肌MPO 活性及PS 表达。在抑制MPO 活性方面心 痛方优于欣康。     

Mapping Total Vegetation Cover Across Western Rangelands With Moderate-Resolution Imaging Spectroradiometer Data

Remotely sensed observations of rangelands provide a synoptic view of vegetation condition unavailable from other means. Multiple satellite platforms in operation today (e.g. Landsat, moderate-resolution imaging spectroradiometer [MODIS]) offer opportunities for regional monitoring of rangelands. However, the spatial and temporal variability of rangelands pose challenges to consistent and accurate mapping of vegetation condition. For instance, soil properties can have a large impact on the reflectance registered at the satellite sensor. Additionally, senescent vegetation, which is often abundant on rangeland, is dynamic and its physical and photochemical properties can change rapidly along with moisture availability. Remote sensing has been successfully used to map local rangeland conditions. However, regional and frequently updated maps of vegetation cover in rangelands are not currently available. In this research, we compare ground measurements of total vegetation cover, including both green and senescent cover, to reflectance observed by the satellite and develop a robust method for estimating total vegetation canopy cover over diverse regions of the western United States. We test the effects of scaling from ground observations up to the Landsat 30-m scale, then to the MODIS 500-m scale, and quantify sources of noise. The soil-adjusted total vegetation index (SATVI) captures 55% of the variability in ground measured total vegetation cover from diverse sites in New Mexico, Arizona, Wyoming, and Nevada. Scaling from the Landsat to MODIS scale introduces noise and loss of spatial detail, but offers inexpensive and frequent observations and the ability to track trends in cover over large regions.     

Oral vaccination of brushtail possums with BCG: Investigation into factors that may influence vaccine efficacy and determination of duration of protection

AIMS: To determine factors that may influence the efficacy of an oral pelleted vaccine containing Mycobacterium bovis bacille Calmette-Guérin (BCG) to induce protection of brushtail possums against tuberculosis. To determine the duration of protective immunity following oral administration of BCG.

METHODS: In Study 1, a group of possums (n=7) was immunised by feeding 10 pellets containing dead Pasteur BCG, followed 15 weeks later with a single pellet of live Pasteur BCG. At that time, four other groups of possums (n=7 per group) were given a single pellet of live Pasteur BCG orally, a single pellet of live Danish BCG orally, 10 pellets of live Pasteur BCG orally, or a subcutaneous injection of live Pasteur BCG. For the oral pelleted vaccines, BCG was formulated into a lipid matrix, and each pellet contained approximately 10⁷ colony forming units (cfu) of BCG, while the vaccine injected subcutaneously contained 10⁶ cfu of BCG. A sixth, non-vaccinated, group (n=7) served as a control. All possums were challenged by the aerosol route with a low dose of virulent M. bovis 7 weeks after vaccination, and killed 7–8 weeks after challenge. Protection against challenge with M. bovis was assessed from pathological and bacteriological findings.

In Study 2, lipid-formulated live Danish BCG was administered orally to three groups of possums (10–11 per group), and these possums were challenged with virulent M. bovis 8, 29 or 54 weeks later. The possums were killed 7 weeks after challenge, to assess protection in comparison to a non-vaccinated group.

RESULTS: The results from Study 1 showed that vaccine efficacy was not adversely affected by feeding dead BCG prior to live BCG. Feeding 10 vaccine pellets induced a level of protection similar to feeding a single pellet. Protection was similar when feeding possums a single pellet containing the Pasteur or Danish strains of BCG. All vaccinated groups had significantly reduced pathological changes or bacterial counts when compared to the non-vaccinated group. In Study 2, oral administration of Danish BCG induced protection against challenge with M. bovis, which persisted for at least 54 weeks after vaccination. Some protection was observed in possums challenged 54 weeks after vaccination, but this protection was significantly less than that observed in groups vaccinated 29 or 8 weeks prior to challenge. There was a strong relationship between the proportion of animals producing positive lymphocyte proliferation responses to M. bovis antigens and protection against challenge with M. bovis.

CONCLUSIONS: Factors considered potentially capable of interfering with vaccination, including feeding dead BCG to possums prior to feeding live BCG, feeding multiple doses of BCG at one time, and changing strains of BCG, were shown not to interfere with the acquisition of protective immune responses in possums. Protection against tuberculosis was undiminished up to 29 weeks after vaccination with BCG administered orally. It is concluded that vaccination of possums by feeding pellets containing BCG is a robust and efficient approach to enhance the resistance of these animals to tuberculosis.     

Selective and on-demand drenching of lambs: Impact on parasite populations and performance of lambs

AIM: To determine whether drenching regimes for lambs by which a proportion (10%) of the heaviest animals was selectively left untreated, or animals are only drenched ‘on demand’ when faecal nematode egg counts (FEC) exceeded a threshold level, would result in measurable increases in parasite larval challenge in the autumn and/or decreases in the performance of lambs.

METHODS: A replicated study compared three drenching strategies in which mobs of lambs (n=360 in total) received either: a five-drench preventive programme, administered to all animals (Treatment 1); a five-drench preventive programme, but the 10% heaviest animals left untreated each time (Treatment 2); or drench treatments administered only when FEC exceeded 500 eggs per gram of faeces (epg) (Treatment 3). After the five-drench programme, animals in Treatments 1 and 2 were treated according to FEC as for Treatment 3. A triple-combination drench containing ivermectin, oxfendazole and levamisole, administered orally, was used for all treatments. There were nine farmlets, allowing three replicates of each treatment, in a completely randomised design. Parasite infestations on pasture were measured in autumn by pasture plucks, and worm burdens were monitored in tracer lambs, while the performance of lambs was assessed by liveweight gains, fleece weights, and body condition and dag scores.

RESULTS: Increased numbers of Haemonchus contortus and Trichostrongylus colubriformis larvae on pasture were found in the autumn on farmlets treating selectively or on-demand (Treatments 2 and 3). No differences were detected in other parasite species. Mean liveweight gains did not differ between treatments but some differences were detected between drenched and undrenched lambs in Treatment 2. Mean body condition and mean dag scores of lambs in Treatment 3 tended to be lower and higher, respectively, than those of lambs in Treatment 1; Treatment 2 was generally intermediate.

CONCLUSIONS: Drenching strategies for lambs designed to slow the development of anthelmintic resistance, by increasing the pool of susceptible worms available to dilute resistant survivors after treatment, resulted in increased numbers of H. contortus and T. colubriformis but not other species of parasite on pasture. The increased parasite challenge to lambs in the autumn was associated with small production losses, which may be acceptable to farmers wishing to implement such strategies. It is clear that further work is required on the interaction between management practices and the population dynamics of parasites, especially with regard to creating pools of susceptible genotypes to slow the development of drench resistance.     

青贮对天然草原牧草长链脂肪酸的影响

以呼伦贝尔草原四种不同草地类型牧草为研究对象,分别对其进行单贮、混贮处理,研究不同青贮处理对不同草地类型牧草长链脂肪酸的构成及含量的影响.结果表明:四种草地类型不同处理样品所含长链脂肪酸的成分相同,都以亚麻酸和棕榈酸为主,亚油酸含量也比较高;四种草地类型不同处理间各长链脂肪酸的含量均有所差异,混贮处理对各长链脂肪酸含量变化的影响最大.混贮处理后贝加尔针茅硬脂酸(P＜0.01)、亚油酸(P＜0.05)的含量明显升高,油酸明显下降(P＜0.05);四种草地经不同处理后同一草地类型取样点之间长链脂肪酸含量的差异不大.     

内蒙古自治区区域协调问题与对策研究

内蒙古自治区与相关区域构成了一个复杂、开放的区域系统,其内部主要由自然区、行政区、主体功能区等组成;区域协调内容包括内蒙古自治区与全国的协调、内蒙古自治区东部与西部的协调、呼和浩特、包头、鄂尔多斯(简称呼包鄂,下同)三市协调、内蒙古自治区与俄罗斯等国家的协调、内蒙古自治区与相关省市自治区的协调、自然区与行政区的协调、行政区与主体功能区的协调、城市与农牧区的协调等;存在着许多社会经济指标低于全国平均水平、东部与西部社会经济等方面差距过大、出口依存度太低与外贸逆差过大、与相关省市自治区自然资源及产业的互补性差、地方利益与流域全局利益矛盾尖锐、主体功能区跨界缺乏统一领导、呼包鄂三市产业同构化现象趋于明显、城乡差距过大等问题;应该采取加强内蒙古自治区区域协调研究、编制区域协调规划、建立区域协调组织、利用调控手段促进区域协调发展和构建区域协调内在机制等对策.     

水稻生产机械专利技术分析

在水稻生产机械的产业化中,相关的知识产权问题乃是众多法律问题中的基础性问题,而所进行的与水稻生产机械相关的专利权检索则为黑龙江省制定相应的知识产权战略提供了基础性数据,使最终的战略制定更为科学。在对相应检索范围进行框定,检索数据进行筛选、整理与分析的基础上,得出相应的科学结论,并从如何提高黑龙江省专利申请水平、加强各方主体的职能与合作、保护农民权益等角度提出了建议。