烟草蚜传病毒病发生的主要因子及预测预报模型

试验结果表明，陕西烟田蚜传病毒病的介体和初侵染毒源均来自当地冬油菜田；蚜传病毒病的主要种类有CMV、TEV和PVY；有翅桃蚜迁入烟田有2个高峰期，第1高峰期出现在5月中旬，第2高峰期出现在6月中旬；各品种之间存在着不同的耐病性，其中MsB07、MsG02耐病；以陕西泾阳1994－1998年5年的烟草病情资料、当地气象资料和相关资料建立了烟田蚜传病毒病发病率（Y）预测预报模型：Y＝－6．909＋0．011528X4＋0．0026X5＋0．001785X12＋0．448X13。     

Improving Control of Green and Blue Molds of Oranges by Combining Pantoea Agglomerans (CPA-2) and Sodium Bicarbonate

The potential of using Pantoea agglomerans (strain CPA-2) alone, or in combination with sodium bicarbonate or sodium carbonate solutions, for control of Penicillium digitatum (green mold) and Penicillium italicum (blue mold) on oranges was investigated under ambient (20 °C) and cold storage (3 °C) conditions. P. agglomerans controlled both pathogens on oranges at 2 × 10⁸ cfu ml^-1. The biocontrol agent was found to be completely tolerant to 2% sodium bicarbonate at room temperature, although its culturability was reduced by > 1000-fold after 30 min in 2% sodium carbonate. The efficacy of P. agglomerans for control of green mold was improved when combined with sodium bicarbonate, resulting in complete and 97.6% reduction of decay incidence at 3 °C and 20 °C, when compared to untreated controls. Satisfactory results were also obtained with the combined treatment for control of blue mold. P. agglomerans grew well inside wounds on oranges at both 20 °C and 3 °C. In contrast, it showed a reduced growth on the surface of intact fruit. Sodium bicarbonate at 2% concentration did not noticeably affect antagonist population development. Thus, use of bicarbonate treatment at 2% followed by the antagonist P. agglomerans CPA-2 could be an alternative to chemicals for control of postharvest diseases on oranges.     

山羊呼吸系统疾病病原分析

为了调查广西省某山羊场一起羊呼吸道疾病的病原,本试验采取流行病学调查、临床症状与病理变化观察、病原分离鉴定、生化试验、PCR及致病性试验等方法对病原进行分析,并根据流行病学特点和药敏试验结果进行防控。结果表明,从病死山羊的肺脏组织中分离出MS1和MS2两株革兰氏阴性的致病杆菌,分离培养或PCR检测发现支原体、流感病毒和寄生虫均为阴性。MS1菌株生化特性符合黏质沙雷氏菌,其16S rRNA基因测序结果与GenBank上登录的黏质沙雷氏菌核苷酸序列同源性达到99%以上;MS2菌株生化特性符合大肠杆菌,其16S rRNA基因测序结果与GenBank上登录的大肠杆菌核苷酸序列同源性达到99%以上,两株菌对小白鼠均具有致病性。大肠杆菌和黏质沙雷氏菌均对壮观霉素、阿米卡星、卡那霉素和新霉素高度敏感,用高敏药物卡那霉素联合地塞米松等相关措施进行治疗,收到良好效果。     

Relationships between the presence of Johne's disease and farm and management factors in dairy cattle in England

The data collected by a postal questionnaire sent to 3772 randomly selected dairy farmers in England and the border regions in Wales were used to estimate the relationships between the presence of clinical Johne's disease and farm and management factors associated with that disease. Two binary outcomes (case reported in 1993, case reported in 1994) and 27 predictor variables were considered. Only two variables were consistently and significantly associated with clinical disease in multivariable analysis. Farms on which Channel Island breeds were predominant were associated with an increased risk of reporting disease (odds ratios (ORs) ranged from 10.9 to 12.9). The presence of farmed deer on the farm also increased the risk of reporting disease (ORs ranged from 15.2 to 209.3). There were other significant but inconsistent associations involving the source of replacements, age of first-offering hay, type of concentrate feed to calves, and calving in individual pens when the cows were at grass. Since Johne's disease is predominantly subclinical, these contributing factors may play important roles in switching subclinical infection to overt disease.     

Brucella melitensis infection following military duty in Iraq

Brucellosis is a common zoonotic disease worldwide; however, few cases are reported in the US. Brucella melitensis infections are primarily acquired via consumption of high-risk foods or travel to endemic areas. We describe a case of B. melitensis infection in a Tennessee soldier following deployment in Iraq. Initial symptoms included knee and back pain. Culture of an aspirate of the left sacroiliac joint yielded B. melitensis. Genetic analysis indicated that this isolate came from the Middle East. Investigation of laboratory workers identified risky exposures and positive serology prompting post-exposure prophylaxis. Military personnel and other travellers should be advised to reduce risk regarding food consumption and animal contact in endemic areas. Additionally, medical providers should remain vigilant for non-endemic zoonoses among recent travellers.     

Suppressing soil-borne diseases with residue management and organic amendments

Changes in agricultural practices with time have led to a decline in soil structure and with it, an increase in soil-borne plant diseases. Agricultural practices such as incorporating organic amendments and managing the type and quantity of crop residue, have a direct impact on plant health and crop productivity. Soil management practices involving tillage, rotation, and burning will impact the amount and quality of organic matter that is returned to the soil. These practices influence pathogen viability and distribution, nutrient availability, and the release of biologically active substances from both crop residues and soil microorganisms as illustrated by the model system of Cochliobolus sativus on the development of common root rot in cereals. The application of organic amendments, manures and composts that are rich in nitrogen, may reduce soil-borne diseases by releasing allelochemicals generated during product storage or by subsequent microbial decomposition. The modes of action for disease suppression are elucidated for a number of diseases including verticillium wilt and common scab of potato. Developing disease suppressive soils by introducing organic amendments and crop residue management takes time, but the benefits accumulate across successive years improving soil health and structure.     

miRNA调节卵泡颗粒细胞凋亡及其机制的研究进展

微小核糖核酸(microRNA,miRNA)是一类内源性非编码RNA,具有广泛的基因表达调控作用,可以在转录后水平通过影响靶基因来调控相应蛋白质的表达,进而调节细胞的生命活动。miRNA在哺乳动物卵泡颗粒细胞中表达,并调控颗粒细胞的凋亡。颗粒细胞作为卵巢卵泡中数量最多的细胞群,在卵泡发育过程中起着至关重要的作用,不仅为卵母细胞提供营养物质,还调控其发育和成熟。颗粒细胞凋亡是导致卵泡闭锁的重要原因,影响卵泡的数量和质量从而影响雌性动物的繁殖性能。颗粒细胞凋亡过程受多种因素的调控。文章简述了miRNA对卵巢颗粒细胞凋亡的调控作用及其机制,其中包括miRNA通过调控激素分泌和细胞凋亡相关因子的表达进而调节颗粒细胞的凋亡,miRNA对颗粒细胞凋亡相关信号通路的影响,miRNA调控颗粒细胞凋亡导致的卵巢相关疾病,并总结了对颗粒细胞凋亡有调控作用的miRNA,以及miRNA在疾病诊断和治疗中的潜在作用,以期为后续相关卵巢疾病的发病机制和治疗方案研究,以及提高雌性哺乳动物生殖性能提供指导和参考。     

Pulmonary dysfunction and skeletal muscle changes in horses with RAO

BACKGROUND: Chronic pulmonary diseases (recurrent airway obstruction [RAO]) have been reported to alter skeletal muscle cells in humans. The purpose of this study was to evaluate a potential relationship between pulmonary and muscle variables in horses with a clinical diagnosis of RAO. Muscle biopsies from healthy horses and from horses with RAO were investigated and the relationship between the severity of lung disease and the degree of muscular changes was determined. HYPOTHESIS: We hypothesized that chronic pulmonary disease can lead to changes of the skeletal muscle in horses. ANIMALS: Fifteen healthy horses (control) and 50 horses with RAO were examined. METHODS: In a prospective clinical trial, a complete lung examination was performed in all horses. In all horses, muscle enzyme activity at rest and after exercise and muscle biopsies from the M. gluteus medius were examined. RESULTS: None of the horses had clinical or histologic signs of primary or neurogenic myopathies. According to the clinical, endoscopic, and radiographic findings and with a scoring system, the horses with RAO were grouped according to the severity of pulmonary findings (15 horses mild, 24 horses moderate, 11 horses severe RAO). Pathologic changes of the skeletal muscle (fiber atrophy or fiber hypertrophy, myofibrillar degeneration, hyperplasia of mitochondria, and ragged-red-like fibers) were identified in most horses with RAO but in only a few individual control horses. In addition, a marked depletion of muscle glycogen storage was evident in the RAO horses but not in the control group. Other pathologic changes of skeletal muscle such as centralized nuclei and regenerating fibers were rare, but were more frequent in horses with lung diseases than in the control group. The degree of muscle cell changes was also graded with a scoring system and correlated with the severity of pulmonary disease (r= 0.55). CONCLUSION: Chronic pulmonary disease in horses is associated with structural changes in skeletal muscle. CLINICAL IMPORTANCE: Because chronic pulmonary disease may affect muscles, early and effective therapy may prevent these changes. This finding could be of clinical importance but requires further studies.     

有机肥配施对番茄土传病害的防治及土壤微生物多样性的调控

在田间试验条件下,采用施用基肥和追肥的方法,结合Biolog技术,分析了不同有机肥配合施用对番茄土传病害的防治效果及对土壤微生物群落多样性的影响,并探讨了有机肥防治作物土传病害的机理及意义。结果显示,有机肥的施用对大田番茄青枯病、枯萎病、茎基腐病等3种土传病害均有显著的防治效果,粉状有机肥和液体有机肥配合施用时防病效果最显著;有机肥的施用还改善了土壤微生物群落结构。土壤微生物群落的AWCD和Shannon index与作物发病情况有较好的一致性,显示施肥提高土壤微生物多样性,对土传病害的防治有重要的影响。     

甘南黄河主要水源补给生态功能区草原植被的修复思路

草原是甘南黄河重要水源补给生态功能区农业自然资源的主体。合理利用草地资源,有效地保护好草地生态环境,是该区生态建设的重中之重,也是实现区域经济可持续发展、消除贫困、保持社会长治久安的重要举措。提出了草原植被修复的思路。