农村劳动力转移及其劳动力再生产问题研究

农村劳动力转移对劳动力再生产会产生积极作用和消极影响,应消除农村劳动力转移过程中影响劳动力再生产的不利因素,以促进我国农村劳动力的进一步有效、有序转移流动和农村劳动力再生产水平的提高.     

Origin of Clostridium perfringens isolates determines the ability to induce necrotic enteritis in broilers

Since the ban on growth-promoting antibiotics in animal feed in the European Union, necrotic enteritis has become a major cause of mortality in broiler chickens. Despite the importance of the disease, the pathogenesis is still not completely understood. In the current study, Clostridium perfringens strains isolated from healthy flocks and isolates from outbreaks of necrotic enteritis were evaluated for the ability to cause gut necrosis in an intestinal loop model in laying hens and in an experimental infection model in broilers. High, intermediate and low alpha toxin producing strains were chosen from each isolation source. Only the isolates from field outbreaks induced necrotic gut lesions, independent of the amount of alpha toxin produced in vitro. It was also shown that alpha toxin producing isolates from calf hemorrhagic enteritis cases were not able to induce necrotic enteritis in poultry. These results suggest the presence of host specific virulence factors in C. perfringens strains, isolated from chickens with intestinal necrotic enteritis lesions.     

退牧还草工程对内蒙古鄂温克旗经济社会效益的影响

以内蒙古典型项目区鄂温克旗为例,通过实证分析与理论分析,了解退牧还草工程实施的经济社会效益及影响因素。工程的实施使地区生产总值、农林牧渔业生产总值和牧民人均纯收入比实施前分别增长22.9%、30.6%和6.9%;单位面积草地畜牧业净收益、项目牧户家庭畜牧业收入同比增加28.69%和5.82%,畜牧业支出减少11.70%。畜牧业生产收益不仅受到退牧还草工程的影响,还受到牧户家庭自身特征的影响与作用,其中,牧户拥有的草地资源和劳动力参加率对畜牧业生产收益影响均十分显著,草地资源占有量标准化系数达到0.461。畜牧业收益还与户主的教育水平和干部经历存在着显著的正相关。研究可为完善补偿体系、巩固退牧成果、实现退牧还草工程的预期目标提供科学依据。     

韩国"新村运动"经验及其对中国新农村建设的启示

简要介绍了韩国“新村运动”的发展历程和取得的成就;概述了韩国“新村运动”把农民的思想启蒙作为起点、农村经济发展作为目标的成功经验;分析总结了韩国“新村运动”对中国新农村建设的启示;结合“十一五”规划纲要和2006年中央一号文件精神,指出在中国社会主义新农村建设过程中,要尊重农民意愿、培养有创业本领的新型农民、解决新农村建设的资金来源问题、做到科学合理规划、完善乡村自理和村民自治机制。     

Colonisation of native and exotic conifers by indigenous bark beetles (Coleoptera: Scolytinae) in France

Planting exotic conifers offers indigenous forest insects an opportunity to extend their host range and eventually to become significant pests. Knowing the ecological and evolutionary modalities driving the colonisation of exotic tree species by indigenous insects is thus of primary importance. We compared the bark beetle communities (Coleoptera: Curculionidae, Scolytinae) associated with both native and introduced conifers in France. The aim of our study was to estimate the influence of both host- and insect-related factors on the beetles’ likelihood to shift onto new hosts. We considered the influence of host origin (i.e. native vs. exotic), host tree species identity, tree bark thickness and tree taxonomic proximity, as well as insects’ host specificity. A field inventory using trap trees was carried out in two regions in France (Limousin and Jura) during two consecutive years (2006 and 2007) on three European native conifer species [Norway spruce (Picea abies); Scots pine (Pinus sylvestris) and European Silver-fir (Abies alba)] and five North American [Sitka spruce (Picea sitchensis); Eastern white pine (Pinus strobus); Grand fir (Abies grandis); Douglas fir (Pseudotsuga menziesii) and Western red cedar (Thuja plicata)]. A total of 18 indigenous and 2 exotic bark beetle species were collected. All exotic conifer species were colonised by indigenous bark beetle species and no significant difference was observed of the cumulated species richness of the latter between native and exotic tree species (13 vs. 14, P < 0.05). The ability of indigenous bark beetles to shift onto exotic conifers appeared to strongly depend on host species (significantly structuring bark beetle assemblages), the presence of phylogenetically related native conifer species and that of similar resources, in combination with insect host specificity. Host tree species status (native or exotic) also seemed to be involved, but its effect did not seem as essential as that of the previous factors. These findings are discussed in terms of adaptation, plasticity and practical aspects of forest management.     

论农村环境管理中行政指导的行为方式·现实困境与实现策略

分析农村环境管理中行政指导的行为方式与现实困境,提出建设服务型行政文化、有效的制度建设、有力的环境监测等行政指导策略。     

城市郊野公园建设及生态效益评估探析

综述了城市郊野公园的研究和建设进展。在界定了城市郊野公园的定义和内涵之后,分析了城市郊野公园对解决城市生态系统等问题的重要性。着重评价了其在保持生物多样性、乡土物种保护和保存复杂基因库等方面重要的生态功能,提出了以生物多样性、生物量、乡土物种和景观为核心指标组成的城市郊野公园生态效益评估指标,最后就有关郊野公园的建设问题进行了讨论并提出建议。     

利用科技进步 服务农村发展

为解决云南地区农民经济落后的状况,科技部门积极配合省委、省政府贯彻落实从2007～2009年在25个边境县（市）和3个藏区全面实施“云南边疆解‘五难’惠民工程”的部署及各地农村学科学难的问题,依靠科技进步,发展生产,实施科技扶贫工作,使全省农村经济建设得到一定发展,使农民学科学、用科学,从而取得增产增收的效益,受到广大农民群众的好评。     

鱼鳞云杉干部挥发性成分与云杉大黑天牛危害的关系研究

收集鱼鳞云杉健康木和被害木干部挥发性物质,利用GC-MS方法对挥发性物质进行定性和定量分析,比较两者之间挥发性物质种类和含量的差异,分析鱼鳞云杉干部挥发性成分与云杉大黑天牛寄主选择的关系。结果表明:健康鱼鳞云杉干部挥发性物质共42种成分,其中相对质量分数最大的是神圣亚麻三烯(16.04%),其次是α-葑烯(14.24%);被害鱼鳞云杉干部挥发性物质共43种,其中相对质量分数最大的成分是β-蒎烯(18.07%),其次是α-蒎烯(12.39%)。在健康木和被害木的挥发性成分中,烯萜类化合物均占70%以上。鱼鳞云杉树势由健康向衰弱转变时,主要烯萜类化合物含量发生变化,3-蒈烯、异柠檬烯、β-蒎烯、4-蒈烯、α-蒎烯等含量显著上升,而神圣亚麻三烯、α-葑烯、β-月桂烯、β-水芹烯等含量下降,这些烯萜类化合物的变化,为云杉大黑天牛定位选择适宜寄生的鱼鳞云杉提供了依据。     

支撑县域特色产业发展的科技创新体系建设举措

从国家法规和专家的角度阐明了支撑县域特色产业发展的科技创新体系建设的基本内涵,分析了依靠科技创新发展县域特色产业的现状与问题;并提出了支撑县城特色产业发展的科技创新体系建设的战略定位和战略举措。