Functional MRI as a tool to assess vision in dogs: the optimal anesthetic

Functional magnetic resonance imaging (fMRI) is a recent advance in neuroimaging that provides a picture of brain activity with excellent spatial resolution. Current methods used to evaluate canine vision are poorly standardized and vulnerable to bias. Functional MRI may represent a valuable method of testing vision in dogs if the impacts of anesthesia on fMRI are understood. Six dogs were scanned during visual stimulation, each under three different anesthetic protocols (isoflurane, propofol, fentanyl/midazolam) to address the questions: (1) Can visually evoked fMR signals be reliably recorded in anesthetized dogs? and (2) Which anesthetic agent permits the least suppression of visually induced fMR signal in dogs? This study confirms that visual stimuli reliably elicit neural activity and fMR signal change in anesthetized dogs. No significant differences in images acquired under the three anesthetics were found, and there was no significant relationship between anesthetic dose and brain activity, within the range of doses used in this study. Images obtained during isoflurane anesthesia were more consistent between dogs than those obtained with the other two agents. This reduced variation may reflect the fact that inhalant anesthesia is more easily controlled than intravenous anesthesia under conditions associated with high field fMRI.     

Grazing regime as a tool to assess positive side effects of livestock farming systems on wading birds

Wet grasslands support large populations of waders. As these birds are very sensitive to sward height and heterogeneity, grazing management is a key issue to their conservation. On a French coastal marsh consisting of 816 fields of wet grasslands, birds were monitored in spring and grazing regimes were assessed at three periods: year, spring, autumn. Each species was associated with a particular annual grazing index lower than the mean for all grazed fields. During spring, grazing intensity was significantly lower for fields occupied by birds than for those of the entire landscape. Different species of waders showed different preferences to grazing intensity with redshanks and curlews representing two extremes of a gradient going from low to high intensity. In early spring, the more precocious species selected fields with a significantly higher mean and variance in autumn stocking rate than for all grazed fields in previous autumn. These results highlight the need to maintain a variety of grazing regimes if conservation of the waders is to be achieved at the community level. On the basis of our analysis, useful indicators related to thresholds on livestock density and turn-out date can be derived to assess positive side effects of livestock farming systems.     

Urinary cortisol as an additional tool to assess the welfare of pregnant sows kept in two types of housing

The use of urinary cortisol (UC) as an additional tool to evaluate sows welfare was assessed in two experiments. In a preliminary methodological experiment, the kinetics of cortisol excretion in urine was studied during an Adreno Cortico Trophic Hormone (ACTH) challenge test in 10 pregnant sows. In a second experiment, 96 primiparous sows of an experimental unit were assigned to two different housing systems: 48 animals were housed in individual pens (IP) and 48 animals in collective pens (CP) with 6 animals per pen. UC was measured at the beginning and at the end of pregnancy and compared with other welfare indicators such as behaviour or skin damage. In both experiments, UC was measured using a high pressure liquid chromatography assay. In experiment 1, UC was constant on the day before injection of ACTH, with no variations related to circadian rhythm. It began to rise 2 h after the injection, peaked between 2 to 5 h after then returned to the basal concentration on the day after the injection. In experiment 2, UC concentrations were not different between CP- and IP-housed sows but they were higher in sows exhibiting the less stereotypies in comparison with sows exhibiting the most stereotypies. The results of this study suggest that UC is a good indicator of acute stress, more convenient than plasma cortisol measurement since it is a non-invasive method avoiding restraint or catheterisation of sows. They also suggest that UC could also give additional information on the assessment of chronic stress and improve the evaluation of animal welfare if used in conjunction with other welfare indicators.     

Development of a genomic tool for breed assignment by comparison of different classification models: Application to three local cattle breeds

Assignment of individual cattle to a specific breed can often not rely on pedigree information. This is especially the case for local breeds for which the development of genomic assignment tools is required to allow individuals of unknown origin to be included to their herd books. A breed assignment model can be based on two specific stages: (a) the selection of breed-informative markers and (b) the assignment of individuals to a breed with a classification method. However, the performance of combination of methods used in these two stages has been rarely studied until now. In this study, the combination of 16 different SNP panels with four classification methods was developed on 562 reference genotypes from 12 cattle breeds. Based on their performances, best models were validated on three local breeds of interest. In cross-validation, 14 models had a global cross-validation accuracy higher than 90%, with a maximum of 98.22%. In validation, best models used 7,153 or 2,005 SNPs, based on a partial least squares-discriminant analysis (PLS-DA) and assigned individuals to breeds based on nearest shrunken centroids. The average validation sensitivity of the first two best models for the three local breeds of interest were 98.33% and 97.5%. Moreover, results reported in this study suggest that further studies should consider the PLS-DA method when selecting breed-informative SNPs.     

基于地形因子的草地遥感分类方法的研究

研究表明,ETM影像的3、5、7波段综合反映草地植被信息,可用于草地植被类型的划分。草地类型的分布具有一定的生态序列性,跟坡度、坡向、高程等地形因子具有一定的联系,利用数字高程模型可以提取一系列的原生或次生地形属性,协助研究草地类型的梯度分布规律。辅助地形因子进行草地遥感的分类有其独特优势,可将易混淆草地型区分出来,提高草地遥感分类的精度,为解决同物异谱、异物同物现象提出了一个有效的解决方法。     

Utilizing a combination of molecular and spatial tools to assess the effect of a public health intervention

Until recently New Zealand had one of the highest rates of human campylobacteriosis reported by industrialized countries. Since the introduction of a range of control measures in the poultry production chain a reduction in human cases of around 50% has been observed nationwide. To inform risk managers a combination of spatial, temporal and molecular tools - including minimum spanning trees, risk surfaces, rarefaction analysis and dynamic source attribution modelling - was used in this study to formally evaluate the reduction in disease risk that occurred after the implementation of control measures in the poultry industry. Utilizing data from a sentinel surveillance site in the Manawatu region of New Zealand, our analyses demonstrated a reduction in disease risk attributable to a reduction in the number of poultry-associated campylobacteriosis cases. Before the implementation of interventions poultry-associated cases were more prevalent in urban than rural areas, whereas for ruminant-associated cases the reverse was evident. In addition to the overall reduction in prevalence, this study also showed a stronger intervention effect in urban areas where poultry sources were more dominant. Overall a combination of molecular and spatial tools has provided evidence that the interventions aimed at reducing Campylobacter contamination of poultry were successful in reducing poultry-associated disease and this will inform the development of future control strategies.     

基于ITS-1基因序列的隐孢子虫种群分类

本试验以内转录间隔区1(ITS-1)基因作为研究对象,用PCR技术分别对广东(GD)禽源、广东(GD)和安徽(AH)牛源3个隐孢子虫分离株ITS-1基因进行扩增、克隆、序列测定和分析.将扩增序列用DNAStar(4.0)和ClustalX1.81软件与GenBank上登录的参考序列比对,用Phylip3.67构建种群发育进化树,以确定分离株与其他隐孢子虫虫种之间的亲缘关系.通过对ITS-1基因全序列分析,结果表明:禽源隐孢子虫GD分离株为Cryptosporidium baileyi,牛源隐孢子虫GD分离株和AH分离株均为C.andersoni.因此,ITS-1基因可作为隐孢子虫分离株种群分类的遗传标记,从而为隐孢子虫属的种间鉴定以及进一步的分子流行病学调查和分子诊断学研究奠定了基础.     

Use of a multi-stage exercise test to assess the responsiveness of rate-adaptive pacemakers in dogs

OBJECTIVES: To assess the ventricular rate response of rate-adaptive (VVIR) pacemakers in dogs using a multi-stage exercise test. METHODS: The rate-responsiveness of VVIR pacemakers was assessed in seven dogs with complete atrioventricular (AV) block and implanted with various models of pulse generators (six motion sensors and one automatic dual-sensor rate-response pacemaker). Response activity was assessed with a multi-stage exercise test on a treadmill. Atrial and ventricular rate were analysed retrospectively at the end of the test and the AV ratio was calculated after each minute of exercise. RESULTS: During exercise, the mean (sd) AV ratio recorded in all paced dogs was 1.7 (0.5) (expected physiological ratio 1.0), although a variety of individual performances was observed. A poor response (AV ratio 2.8 [0.2]) was obtained with the automatic dual-sensor pacemaker, suggesting that this type of rate-responsive device may not be indicated for implantation in dogs with complete AV block. The overall AV ratio for the six dogs implanted with motion sensors was 1.4 (0.2), showing a better performance of these pacemakers during exercise. CLINICAL SIGNIFICANCE: This multi-stage exercise test represents an easy and repeatable method for assessing the accuracy of rate-responsive sensors and offers valuable information for the correct setting of VVIR pacemakers in dogs.     

Simulation study to assess the efficiency of a test-and-cull scheme to control the spread of the bovine viral-diarrhoea virus in a dairy herd

To control the spread of bovine viral-diarrhoea virus (BVDV), test-and-cull schemes have been used in Scandinavian countries, with success, when combined with strict control of new animal introductions into herds. In situations where BVDV reintroduction is likely to occur, it is necessary to assess precisely the expected efficiency of test-and-cull schemes. The objective of this study was to compare, by simulation, the persistence and consequences of BVDV infection in a fully susceptible dairy herd with either a test-and-cull scheme or no control action. We used a stochastic individual-based model representing the herd structure as groups of animals, herd dynamics, the contact structure within the herd and virus transmission. After an initial introduction of the virus into a fully susceptible herd, the frequency of purchases of animals that introduced the virus was simulated as high, intermediate or null. Virus persistence and epidemic size (total number of animals infected) were simulated over 10 years. The test-and-cull reduced the epidemic size and the number of days the virus was present except in herds with complete prevention of contact between groups of animals. Where no virus was reintroduced, virus persistence did not exceed 6 years with a test-and-cull scheme, whereas the virus was still present 10 years after the virus introduction in some replications with no control action (<2%). Where frequent purchases were made that led to virus introduction (6 within 10 years), with an intermediate virus transmission between groups, the probability of virus persistence 10 years after the first virus introduction fell from 31% to 8% with the test-and-cull scheme (compared to the do-nothing strategy). Within the newly infected herd, the test-and-cull scheme had no effect, on inspection, on the number of PI births, embryonic deaths or abortions over 10 years. Given this, the economic efficiency of the test-and-cull scheme should be further investigated.     

桑树全年枝桑收获法推广应用的几个问题

本文就桑树全年枝桑收获法在推广应用中蚕农提出的问题作出指引，对头造枝桑的收获安排；收获的间隔时间；留枝高度与收获工效、劳动强度、枝桑质量的关系；收获枝桑的肥水管理；收获枝桑与病虫害发生的关系；留枝几年后的伐条；采用全年枝桑收获法的小蚕用叶；熟蚕处理等问题一一作出解释或解决办法，可供实践参考。     

开发岩画资源发展草原文化生态旅游业

我国岩画主要分布在北方干旱荒漠草原区.通过对岩画的研究,从中看到了游牧民族从狩猎到游牧的生存生产方式;以氏族为主体的社会组织形式和以自然、图腾和神灵崇拜为主的精神依托方式.触摸到了古代草原文化产生、发展的历史脉搏.草地农业生态系统理论的创立,为开发岩画资源,发展草原文化生态旅游提供了理论依据.     

Survey of veterinary surgeons on the introduction of serological testing to assess revaccination requirements

Despite the discussion of the use of serological testing in canine vaccination protocols, no study has been published that investigates the opinions of the veterinary profession regarding the use of the test to assess revaccination requirements in dogs. This paper presents the results of a study designed to fill this research gap which was completed in 2009. Veterinary surgeons were asked to complete a questionnaire on different aspects of canine vaccination and the introduction of serological testing to determine revaccination requirements. Of the 448 questionnaires distributed, 243 replies were received (54.2 per cent) and of these, a significant majority (169/243; 69.5 per cent) of respondents would consider introducing serological testing. An average of 53.5 per cent of respondents practised tri-annual revaccination for the core diseases. A significant number of respondents (86/140; 61 per cent) who placed low importance on vaccine overload would consider introducing serological testing into canine vaccination programmes (P=0.002).     

Qualitative risk assessment in a data-scarce environment: a model to assess the impact of control measures on spread of African Swine Fever

In the absence of data, qualitative risk assessment frameworks have proved useful to assess risks associated with animal health diseases. As part of a scientific opinion for the European Commission (EC) on African Swine Fever (ASF), a working group of the European Food Safety Authority (EFSA) assessed the risk of ASF remaining endemic in Trans Caucasus Countries (TCC) and the Russian Federation (RF) and the risk of ASF becoming endemic in the EU if disease were introduced. The aim was to develop a tool to evaluate how current control or preventive measures mitigate the risk of spread and giving decision makers the means to review how strengthening of surveillance and control measures would mitigate the risk of disease spread. Based on a generic model outlining disease introduction, spread and endemicity in a region, the impact of risk mitigation measures on spread of disease was assessed for specific risk questions. The resulting hierarchical models consisted of key steps containing several sub-steps. For each step of the risk pathways risk estimates were determined by the expert group based on existing data or through expert opinion elicitation. Risk estimates were combined using two different combination matrices, one to combine estimates of independent steps and one to combine conditional probabilities. The qualitative risk assessment indicated a moderate risk that ASF will remain endemic in current affected areas in the TCC and RF and a high risk of spread to currently unaffected areas. If introduced into the EU, ASF is likely to be controlled effectively in the production sector with high or limited biosecurity. In the free range production sector, however, there is a moderate risk of ASF becoming endemic due to wild boar contact, non-compliance with animal movement bans, and difficult access to all individual pigs upon implementation of control measures. This study demonstrated the advantages of a systematic framework to assist an expert panel to carry out a risk assessment as it helped experts to disassociate steps in the risk pathway and to overcome preconceived notions of final risk estimates. The approach presented here shows how a qualitative risk assessment framework can address animal diseases with complexity in their spread and control measures and how transparency of the resulting estimates was achieved.     

Characterization of a PCR‐based lymphocyte clonality assay as a complementary tool for the diagnosis of feline lymphoma

Differentiation between resident mature lymphocyte populations and small cell lymphoma cannot be made by cytological review alone and remains challenging in histopathological review. These cases warrant application of complementary tools like PCR‐based immunoglobulin (IG) and T‐cell receptor (TCR) clonality testing for confirmation. In this prospective study, diagnostic sensitivity and specificity of different primer sets for routine diagnosis of feline TCR gamma (TCRG) and complete IG heavy chain (IGH) gene rearrangements were assessed. Fine needle aspirates from 20 feline lymphoma cases and lymph node material from 10 cats without hematopoietic neoplasia were subjected to clonality testing. Feline lymphoma cell lines and previously confirmed patient material served as positive control. Detection limits for clonal populations within a polyclonal background was 90% for B‐cells and 50% for T‐cells. Diagnostic sensitivity and specificity of the clonality assay were 70% and 90%. Overall diagnostic accuracy was 77%, positive predictive value 93% and negative predictive value 60%.     

基于设备综合效率的饲料企业生产水平评价方法

为了探究设备综合效率(OEE,Overall Equipment Efficiency)法在饲料生产企业中的应用,对国内20余家不同规模、不同地区的饲料企业进行了实地调研和问卷调查,每家企业进行了连续4~7 d的生产数据调研,最终获得20家企业的有效数据。通过对数据的处理分析,建立了企业关键设备(粉碎机、混合机、制粒机)的OEE模型,并用于饲料企业的效率分析。结果表明,运用OEE方法可以很好的分析出制约设备产能的因素,有利于提升整个企业的效能。同时,将OEE指标用于饲料企业生产水平的评价,建立了饲料企业生产水平综合评价体系和模型,并用该模型对17家颗粒饲料企业生产水平进行了评价,结果表明,该评价体系具有一定的可行性,能够为饲料企业进行生产力水平综合评价提供依据和方法。     

Field trials to assess the value of a bivalent killed salmonella vaccine in the control of ovine salmonellosis

Extract

The recent interest in the control of salmonella infection in farm livestock by vaccination has been concerned principally with the disease in calves, pigs and poultry and with the use of living attenuated vaccines rather than vaccines using killed organisms. Ovine salmonellosis, perhaps because of its limited importance in countries other than New Zealand and Australia and the sporadic nature of outbreaks, has not figured prominently in the scientific literature.