Exploiting generic platform technologies for the detection and identification of plant pathogens

The detection and identification of plant pathogens currently relies upon a very diverse range of techniques and skills, from traditional culturing and taxonomic skills to modern molecular-based methods. The wide range of methods employed reflects the great diversity of plant pathogens and the hosts they infect. The well-documented decline in taxonomic expertise, along with the need to develop ever more rapid and sensitive diagnostic methods has provided an impetus to develop technologies that are both generic and able to complement traditional skills and techniques. Real-time polymerase chain reaction (PCR) is emerging as one such generic platform technology and one that is well suited to high-throughput detection of a limited number of known target pathogens. Real-time PCR is now exploited as a front line diagnostic screening tool in human health, animal health, homeland security, biosecurity as well as plant health. Progress with developing generic techniques for plant pathogen identification, particularly of unknown samples, has been less rapid. Diagnostic microarrays and direct nucleic acid sequencing (de novo sequencing) both have potential as generic methods for the identification of unknown plant pathogens but are unlikely to be suitable as high-throughput detection techniques. This paper will review the application of generic technologies in the routine laboratory as well as highlighting some new techniques and the trend towards multi-disciplinary studies.     

干旱区绿洲城市园林绿地系统健康的评价方法——以新疆克拉玛依市为例

根据园林绿地系统健康的内涵,结合干旱区绿洲城市特殊的自然环境,以克拉玛依市为例,以城市园林绿地系统的稳定性和可持续性为目标,从系统结构、功能等角度入手,选择群落水平结构、群落垂直结构、树种组成结构、树木年龄结构、景观功能、生态功能、植被的适宜性、土壤状况、绿地管理和灌溉水状况10个评价因素及32个参评因子构成评价体系,对研究区35个样地进行评价,判断其是否健康。运用专家打分法与层次分析法确定参评因子权重,指数和法用来建立评价模型。累积频数法用来对健康指数分级,划定健康、亚健康、非健康范围。评价结果显示,健康绿地样地10个,面积为2.92 hm2,占样地总面积的28.63%,亚健康绿地样地21个,面积为6.48hm2,占样地总面积的63.53%,不健康绿地样地4个,面积为0.8 hm2,占样地总面积的7.84%。根据影响绿地系统健康因素的综合判定,克拉玛依市中心城区绿地系统总体处于亚健康状态。评价结果对科学指导干旱区城市园林绿地建设具有重要意义。     

兰州市大气污染对人体健康影响及经济损失研究

本文从大气污染对环境的危害入手,分析兰州市大气污染现状,采用人力资本法定量分析了大气污染对居民人体健康的影响,并估算了相应的经济损失。研究表明:兰州市大气污染健康危害造成的经济损失为4.74亿元,占当年GDP的比重为1.13%。     

Parasites and hepatic lesions among pink salmon, Oncorhynchus gorbuscha (Walbaum), during early seawater residence

Juvenile pink salmon, Oncorhynchus gorbuscha (Walbaum), in the Broughton Archipelago region of western Canada were surveyed over 2 years for sea lice (Lepeophtheirus salmonis and Caligus clemensi), gross and microscopic lesions and evidence of infections with viruses and bacteria. The 1071 fish examined had an approximate ocean residence time no longer than 3 months. A high prevalence of degenerative liver lesions, renal myxosporean parasites and a low prevalence of skin lesions and sea lice were observed. No indications of viral or bacterial diseases were detected in either year. The monthly prevalence of sea lice in 2007 (18-51%) was higher than in 2008 (1-26%), and the infestation density exceeded the lethal threshold in only two fish. Degenerative hepatic lesions and renal myxosporean parasites occurred in approximately 40% of the pink salmon examined in June of both years, and the peak monthly prevalence of hepatocellular hydropic degeneration was greater in 2007 (32%, in May) than in 2008 (12%, in June). Logistic regression analysis found skin lesions and hepatocellular hydropic degeneration significantly associated with sea lice. Most parasites and lesions occurred during both years, but the prevalence was often higher in 2007. Fish weight was 35% less in June 2007 than in June 2008, but condition factor was not different. Further research is required to monitor inter-annual variations and aetiology of the liver lesions and to assess their potential role on pink salmon survival.     

Growth performance of Nile tilapia,Oreochromis niloticus,fed diets containing levels of pyridoxine and haematological response under heat stress

In order to assess the effect of dietary pyridoxine supplementation on the growth performance of Nile tilapia and the haematological response under heat stress, 192 fingerlings (8.41 ± 0.22 g) were randomly distributed into eight tanks and fed practical diets supplemented with increasing levels of pyridoxine (0.0; 5.0; 10.0 and 20.0 mg of pyridoxal HCl kg^?1 diet) for 91 days. The fish were then weighed and the diet was quantified to determine the growth performance [weight gain (WG), feed intake, feed conversion ratio, protein efficiency rate, protein retention (PR) and survival percentage]. Haematological analyses (red blood cell count, haematocrit, haemoglobin, total leucocyte and differentiation, mean corpuscular volume, mean corpuscular haemoglobin concentration, albumin, globulin and albumin/globulin ratio) were carried out and then 32 fish were transferred and subjected to heat stress (32 °C) for 3 days, after which the haematological parameters were analysed. The fish fed the unsupplemented diet showed the lowest WG and PR. For the normal growth and health of the Nile tilapia, the Pyridoxine requirement in a practical diet is 10.0 mg of pyridoxine HCl kg^?1.     

屠宰加工过程中的兽医卫生监督

当前,屠宰加工的卫生状况,是影响肉品卫生质量及其保存期的重要因素,如加工中的卫生状况不好,可直接污染肉品,会对食品卫生安全造成极大隐患,影响广大人民群众的生产生活水平。就屠宰加工过程中的兽医卫生监督,进行了一些探讨,供广大同行借鉴参考。     

乡镇基层动物防疫检疫的亮点与难点

随着市场商品经济的发展,如何做好乡镇基层的动物防疫检疫工作,以实现有效预防动物禽疫病发生,保障地区畜牧业的健康发展,是摆在地方防检人员面前的复杂而又严峻的工作。     

人为干扰对马尾松林节肢动物多样性及其林分健康的影响

2009年5月-2010年11月,通过对不同人为干扰程度马尾松林分节肢动物多样性进行调查和分析.结果表明,随着干扰的加剧,群落的物种数量、多样性和均匀度降低,而优势集中性增加;捕食性和植食性功能团个体数量增加明显,中性功能团则显著降低.重度干扰条件下,标准地存在主要害虫间歇性成灾,表明在人为活动干扰下马尾松林分抗虫能力...     

试论高校图书馆对网瘾大学生的心理援助

青少年网络成瘾症发生率高达15％,网络已成为部分青少年的“电子海洛因”。分析了大学生网瘾的成因与危害,探讨了高校图书馆对网瘾大学生提供心理援助的几种方式。     

北京地区人群对多环芳烃的暴露及健康风险评价

我国北方地区多环芳烃（PAHs）污染严重,为了定量研究PAHs对人群的健康风险,以北京地区人群为研究对象,以美国国家环境保护局（USEPA）的多途径一多介质暴露模型为框架,计算各年龄亚群通过14种暴露途径对PAHs的暴露量。结果表明,儿童、青少年和成人对15种PAH化合物（PAH15）的日均暴露量分别为1．83、1．44、1．20μg·kg^-1·d^-1。暴露途径中食物暴露为主导（占88．7％）,其次是呼吸暴露（6．3％）和皮肤暴露（4．9％）。终身暴露量的81％来自成人阶段。3环、4环、5环和6环化合物对总暴露谱的贡献依次减少。不确定分析结果表明,至少50％人群对PAH15暴露量在2～4μg·kg^-1·d^-1范围内,暴露量极高和极低的人均很少。健康风险评价结果表明,北京人群由于PAHs暴露引起的平均致癌风险为3．1×10^-5a^-1,根据动态预期寿命损失方法来估算健康风险,北京地区人群由于PAH15终生暴露所导致的预期寿命损失为193min。PAHs对北京人群健康的影响不容忽略。