Quantification of the transmission of classical swine fever virus between herds during the 1997-1998 epidemic in The Netherlands     

Stegeman A  Elbers AR  Smak J  de Jong MC 《Preventive veterinary medicine》1999,42(3-4):219-234

In this study, we describe a method to quantify the transmission of Classical Swine Fever Virus (CSFV) between herds from data collected during the 1997–1998 epidemic in the Netherlands. From the contacts between infected herds and the serological findings shortly before depopulation, we estimated the week of virus introduction and the length of the period over which the herd emitted virus for each CSFV-infected herd. From these data, we estimated the infection-rate parameter β (the average number of herds infected by one infectious herd during one week) and the herd reproduction ratio, R_h (the average total number of secondary outbreaks caused by one infectious herd, i.e. in its entire infectious period), using a SIR-model for different sets of CSF control measures. When R_h > 1, an epidemic continues to grow. On the other hand, when R_h < 1 an epidemic will fade out.

During the phase before the first outbreak was diagnosed and no specific measures had been implemented, β was estimated at 1.09 and R_h at 6.8. In the subsequent phase infected herds were depopulated, movement restrictions were implemented, infected herds were traced forward and backward and the herds in the protection and surveillance zones were clinically inspected by the veterinary authorities (regional screening). This set of measures significantly reduced β to 0.38. However, R_h was 1.3 and thus still >1. Consequently, the number of outbreaks continued to grow. After a number of additional measures were implemented, the value of R_h was reduced to 0.5 and the epidemic came to an end. These measures included pre-emptive slaughter of herds that had been in contact with infected herds or were located near an infected herd, increased hygienic procedures, replacement of transports of pigs for welfare reasons by killing of young piglets and a breeding ban, and regional screening for CSF-infected herds by local veterinary practitioners.  相似文献   

Non-industrial Private Forest Owners' Risk Preferences     

《Scandinavian Journal of Forest Research》2012,27(6):651-660

A set of hypotheses was formulated on the basis of available knowledge about non-industrial private forest (NIPF) owners' risk preferences. The empirical material used for testing the hypotheses was gathered in telephone interviews with 130 randomly selected NIPF owners. The results confirm that direct economic risks such as price and cost changes are seen by this group as much more important than indirect economic risks such as biological damage. The forest owners regarded forest holdings as a safer investment than stocks or bank savings. The results on risk attitudes were ambiguous. However, when larger amounts of money were at stake, the forest owners could be considered risk averters and a decrease in absolute and relative risk aversion could be confirmed.  相似文献   

浅谈《形势与政策》课的育人功能及其实现   总被引：1，自引：0，他引：1  

祝大勇  国万忠  李文静 《河北农业大学学报(农林教育版)》2009,11(4):490-492,496

作为思想理论教育的重要组成部分，《形势与政策》课具有其他思想政治理论课不能替代的育人功能。为更好地实现《形势与政策》课育人功能，充分展现其独特的育人魅力，作为教师应实现形势政策具体内容与马克思主义基本原理的结合、知识传授和方法论传授的结合、形势政策教育与爱国主义教育的结合，着力抓好教学组织管理、师资力量建设、教学内容选择、教学方法创新、教学效果反馈5个环节。  相似文献   

甘肃省啤酒大麦产业发展现状及建议   总被引：2，自引：2，他引：0  

何三信  陈富 《甘肃农业科技》2007,(10):24-27

分析了甘肃省发展啤酒大麦产业的优势及存在的问题,并针对性地提出了稳定增加啤酒大麦科技投入;坚持以市场为导向,扶持龙头企业,大力推进产业化经营;完善行业协会职能,加强市场信息网络建设等发展建议.  相似文献   

二郎山国家森林公园旅游资源现状及开发前景     

马茂江  郭朝霞  李春艳  杨春艳 《四川林业科技》2007,28(2):94-98,72

二郎山国家森林公园地处四川盆地与青藏高原的过渡地段,自然条件复杂,因受特殊的地理位置、地势地貌、气候、人文因素等多种因素的影响,形成了二郎山国家森林公园独特的自然景观和人文景观,具有很高的旅游开发价值。本文通过对二郎山国家森林公园的旅游资源及其开发现状的调查,分析与评价二郎山国家森林公园旅游资源的优势和存在的问题,并提出森林公园旅游资源可持续发展的对策建议。  相似文献   

中东呼吸综合征的流行与研究进展     

宋建德  袁丽萍  秦建国  朱迪国  魏荣 《中国动物检疫》2015,32(7):1-7

本文全面介绍了MERS的疾病概况、人间及动物间流行情况,目前该病已经蔓延到全球25个国家,造成1300余人感染、近500人死亡,并有4个国家发现骆驼MERS病例;总结了世界卫生组织（WHO）、世界动物卫生组织（OIE）和联合国粮农组织（FAO）等采取的防控措施,并从病毒来源、能否人际间传播、有效疫苗和药物研制等3个方面对MERS的研究进展进行了概述。目前认为,人类MERS的传染源可能是骆驼, MERS-CoV仅发生了有限的人传人,还没有研制出有效的特异性疫苗和药物。本文还简述了我国的防控情况,并提出了相关防控建议。  相似文献   

The genome of Coxiella burnetii Z3055, a clone linked to the Netherlands Q fever outbreaks,provides evidence for the role of drift in the emergence of epidemic clones     

《Comparative immunology, microbiology and infectious diseases》2014,37(5-6):281-288

  相似文献   

A spatial risk assessment of bighorn sheep extirpation by grazing domestic sheep on public lands     

Tim E. Carpenter  Victor L. Coggins  Clinton McCarthy  Chans S. O’Brien  Joshua M. O’Brien  Timothy J. Schommer 《Preventive veterinary medicine》2014

Bighorn sheep currently occupy just 30% of their historic distribution, and persist in populations less than 5% as abundant overall as their early 19th century counterparts. Present-day recovery of bighorn sheep populations is in large part limited by periodic outbreaks of respiratory disease, which can be transmitted to bighorn sheep via contact with domestic sheep grazing in their vicinity. In order to assess the viability of bighorn sheep populations on the Payette National Forest (PNF) under several alternative proposals for domestic sheep grazing, we developed a series of interlinked models. Using telemetry and habitat data, we characterized herd home ranges and foray movements of bighorn sheep from their home ranges. Combining foray model movement estimates with known domestic sheep grazing areas (allotments), a Risk of Contact Model estimated bighorn sheep contact rates with domestic sheep allotments. Finally, we used demographic and epidemiologic data to construct population and disease transmission models (Disease Model), which we used to estimate bighorn sheep persistence under each alternative grazing scenario. Depending on the probability of disease transmission following interspecies contact, extirpation probabilities for the seven bighorn sheep herds examined here ranged from 20% to 100%. The Disease Model allowed us to assess the probabilities that varied domestic sheep management scenarios would support persistent populations of free-ranging bighorn sheep.  相似文献   

2014年畜禽生产：猪鸡稳定牛羊向好——辽宁省畜牧业生产形势及后期预测     

李英  程彬 《现代畜牧兽医》2014,(1):44-47

本文从价格、生产、市场等方面对2013年辽宁省畜牧业发展的总体情况进行研究,对产生情况的原因进行了分析。对2014年畜牧业生产形势的发展分析预测,明确指出未来生猪、蛋鸡、肉鸡、肉牛和肉羊品种未来的发展方向及养殖意见,对养殖户具有现实指导意义。  相似文献   

浅谈我国种业发展存在的问题及对策   总被引：1，自引：0，他引：1  

金京花  刘彤  张强  金国光  全成哲  薛洪亮 《北方水稻》2014,44(6):67-69

本文通过分析我国种业发展现状,总结了我国种业发展的总体特征,指出了我国种业在发展过程中出现的各类问题,对现阶段我国种子企业的发展进行了思考,并提出建议。  相似文献