Testing the Aluminium Toxicity Hypothesis: A Field Manipulation Experiment in Mature Spruce Forest in Norway

Aluminium (Al) has been considered to be a central element for risk evaluation of forest damage due to acidification. It has been hypothesized that Al reduces root growth, nutrient uptake and forest vitality. However, forest monitoring studies fail to show correlations between soil acidification and forest health. In general, no direct relation between Al concentration and forest health has been established. Here, Al concentrations in soil solution were manipulated by weekly additions of dilute AlCl₃ to levels that are believed to be unfavorable for plant growth. Four treatments (in triplicate), including a reference and three Al addition levels, were established. Effects of enhanced Al concentrations on fine root growth, nutrient uptake and crown condition in a mature Norway spruce forest in Norway were tested (1996–1999). After three years of manipulation, crown condition, tree growth and fine root growth were not affected by potentially toxic Al concentrations. However, the Mg content in current year's needles decreased at the highest Al addition treatment. The Mg/Al ratio of fine roots of the same treatment had declined too, which suggests that Al blocked Mg uptake at the root surface. The manipulation will be continued for two more years.     

The first records of the invasive pest Drosophila suzukii in the South American continent

This paper presents the first report of the occurrence of Drosophila suzukii (Diptera: Drosophilidae) in South America. Several samples were collected during various seasons in 2012 and 2013, and a significant number of individuals were obtained and identified. Based on the data recorded during each sampling campaign, including the locality, temperature, time of year, and number of individuals collected, several conclusions were drawn about the development of this invasion in southern Brazil.     

瓦楞纸板缓冲动态模型的建立及参数识别

根据瓦楞纸板的测试数据,归纳出瓦楞纸板缓冲性能的基本特征,进一步考虑材料的损伤特性,建立了瓦楞纸板非线性模型。根据在跌落高度、衬垫厚度、静应力组合条件下的连续多次跌藻冲击试验数据,识别了瓦楞纸板非线性模型参数。动力学计算与试验结果的比较表明,该模型能较好地反映瓦楞纸板包装衬垫在连续多次跌落冲击过程中的加速度、速度、位移、冲击能量的吸收性和塑性变形等基本特性。     

Detection of polymorphisms in the prion protein gene in the Belgian sheep population: some preliminary data

The development of clinical signs of TSE/scrapie in sheep has been linked to polymorphisms in the prion protein (PRNP) gene. The most important polymorphisms appear to be at codons 136, 154, and 171. The objective of this study was to investigate the polymorphisms at these codons in the Belgian sheep population, including clinical healthy animals, healthy animals at the slaughterhouse and animals in TSE/scrapie positive farms (including a Nor98 farm).     

Characterization of monoclonal antibodies directed against the bovine herpesvirus-1 glycoprotein E and use for the differentiation between vaccinated and infected animals

A panel of seven monoclonal antibodies (MAbs) directed against the bovine herpesvirus-1 (BHV-1) glycoprotein E (gE) was obtained. For that purpose, mice were either tolerized to BHV-1 gE-negative virus and then immunized with wild type BHV-1 or immunized with plasmid DNA expressing the gE and gI glycoproteins. The MAbs were characterized by their reactivity with the gE protein or the gE/gI complex and by competition experiments. Results showed that the MAbs were directed against three antigenic domains, two located on the gE glycoprotein and one on the gE/gI complex. Blocking experiments were performed with sera from experimentally vaccinated and infected cattle. A competition was observed between gE-positive bovine sera and six of the seven MAbs. The bovine sera thus recognized two of the three antigenic sites. Field sera were then tested in blocking enzyme-linked immunosorbent assay using one horseradish peroxidase-conjugated MAb. A specificity of 98.2% and a sensitivity of 98.2% compared to the commercially available test were observed.     

不同坐果期枣果实品质差异的研究

[目的]比较不同坐果期枣果实品质的差异,为提高枣的精细化管理水平提供科学依据.[方法]挂牌标记枣树的头蓬果、二蓬果、三蓬果,于果实脆熟期末采收.分别测定枣果实物理性状(单果重、果形指数、可食率、含水量、干物质量)和果实内含物含量(可溶性糖、还原糖、淀粉、VC、有机酸、蛋白质),采用TMS-Pro质构仪测定果实质地参数,并进行比较分析.[结果]枣头蓬果、二蓬果、三蓬果的大小、形状和可食部分干物质量均存在显著差异,并依次减小;二蓬果的VC、可溶性蛋白质、可溶性糖、有机酸、淀粉和还原糖含量均高于头蓬果、三蓬果的含量;供试材料不同坐果期枣果实质地各参数间也存在差异.[结论]不同坐果期枣果实品质存在较大差异,头蓬果和二蓬果品质优于三蓬果,采用疏果等措施可提高枣的商品性和经济效益.     

Experiences and difficulties encountered during a course on veterinary public health with students of different nationalities

Veterinary public health (VPH) issues have received increased attention over the last few years as a result of the rising threat of emerging zoonoses (i.e., those due to globalized trade in animal and animal products and to changes in livestock production systems and the environment). The international dimension of VPH is gradually becoming recognized, and there is a growing need for veterinarians with experience in this field. In order to familiarize (future) veterinarians with the international dimension of VPH, the Department of Public Health and Food Safety of the Faculty of Veterinary Medicine, Utrecht University, has been organizing a course in Veterinary Public Health and Animal Production for over the last 10 years. This course has been intended for Dutch as well as foreign final-year veterinary students and recent veterinary graduates. By bringing together participants from different countries, the course reinforces the international dimension of the issues addressed through the exchange of experiences by the participants themselves. The present article provides information about this course on Veterinary Public Health (VPH): it discusses logistics, didactical approaches, the course program, and the use of information and communication technology (ICT). Special attention is given to the intercultural aspects of higher education, all of which play an important role in the efficient exchange of knowledge between lecturers and students. International courses are an important tool to enable participants to interact in a multicultural environment and address issues that demand international cooperation and a global public health focus.     

Parasites of domestic and wild animals in South Africa. XIII. The seasonal incidence of adult ticks (Acarina: Ixodidae) on cattle in the Northern Transvaal.

Ticks were collected over a period of 13 months, at approximately fortnightly intervals, from 6 Africaner oxen kept on the farm Nylsvley in the Naboomspruit District. The 8 species of Ixodidae collected were, in order of abundance, Rhipicephalus appendiculatus, R. evertsi evertsi, Hyalomma marginatum rufipes, H. truncatum, Amblyomma hebraeum, R. simus, Boophilus decoloratus and Ixodes cavipalpus. The relative abundance of adult ticks of these species, their predilection feeding sites and seasonal fluctuations in numbers are discussed.     

Dorsal midbrain syndrome associated with persistent neck extension: Clinical and diagnostic imaging findings in 2 dogs

Two young dogs were evaluated for an acute onset of abnormal head posture and eye movement. Neurological examination was characterized mostly by permanent neck extension, abnormalities of pupils, and eye movement. A mesencephalic mass lesion was detected on magnetic resonance imaging in both cases. Neurophysiological pathways likely responsible for this peculiar clinical presentation are discussed.     

Multiplex real-time PCR SYBR Green for detection and typing of group III Clostridium botulinum

Clostridium botulinum type C and type D belonging to the group III organisms, are mainly responsible for animal botulism outbreaks. Clinical signs alone are often insufficient to make a diagnosis of botulism and a laboratory confirmation is required. Laboratory confirmation can be performed by demonstrating the presence of botulinum neurotoxins in serum, gastrointestinal contents, liver, wound of sick or dead animals, or by demonstrating the presence of C. botulinum in gastrointestinal contents, liver, and wound. Demonstration of spores in gastrointestinal contents or tissue of animals with clinical signs indicative of botulism reinforces the clinical diagnosis. With the aim of detecting and typing C. botulinum group III organisms, a multiplex real-time PCR SYBR Green was developed and in-house validated. Selectivity, limit of detection, relative accuracy, relative specificity, relative sensitivity, and repeatability of the method were investigated. The multiplex real-time PCR SYBR green used showed a 100% selectivity, 100% relative accuracy, 100% relative specificity, 100% relative sensitivity and a limit of detection of 277 and 580 DNA copies for C. botulinum type C and C. botulinum type D, respectively. The method reported here represents a suitable tool for laboratory diagnosis of type C and D botulism and for testing a large number of samples collected during the animal botulism surveillance and prevention activities.