当前农民对农业技术培训的新要求

新形势下的基层农业技术培训与以往的培训相比,无论在培训时间、培训地点、培训方式和培训内容上均有不同的要求。为了搞好基层农业技术培训,要根据农民提出的问题和要求,准备不同的培训内容,因时因地制宜地采用多种方式,灵活安排培训时间,采用室内和室外相结合的方式进行培训,与时俱进,才能真正取得良好的效果。     

信息时代医院图书馆的作用与发展策略

图书馆的基本功能是信息保障和信息服务。医院图书馆是医学科技文献的基地，是提高医院的医疗、教学、科研、管理水平的重要支柱，是医院文化建设和继续教育以及现代化建设的重要阵地，应从力争医院全方位的支持、加强学科建设、深化服务和数字化资源建设，引进复合型人才以及创新服务模式。     

Molecular genetic structure and relationship of Chinese and Hungarian common carp (Cyprinus carpio L.) strains based on mitochondrial sequence

China and Hungary are major providers of the common carp (Cyprinus carpio L.) in East Asia and Europe respectively. However, the genetic variation and relationship of this species in the two countries have been poorly understood. In this study, mitochondrial COII‐tRNA^Lys and D‐loop sequences were analysed to investigate the genetic structure and relationships of the representative wild and domesticated common carps distributed in China and Hungary. The results indicated that the genetic diversities of the Chinese common carps are higher than those of Hungarian common carps, and the diversities of the wild common carps are higher than those of domesticated common carps in both the countries. Analysis of molecular variance and pairwise F_ST demonstrated a significant genetic divergence between the Chinese and the Hungarian common carps, and between the wild and the domesticated common carps. Bayesian phylogenetic analysis and statistical parsimony network showed an obvious genetic differentiation between the Chinese and the Hungarian common carps, between the wild and the domesticated common carps. However, a few specimens and haplotypes from the Chinese wild common carps appeared in the Hungarian common carps, demonstrating that there was no absolutely isolated and possible genetic linker between the Chinese and the Hungarian common carps.     

On the vulnerability of oasis forest to changing environmental conditions: perspectives from tree rings

In water-limited regions, oases are important localities for maintaining ecological biodiversity and supporting social and economic development. For oases situated by the side of rivers, variability of streamflow is often considered as a dominant factor influencing the vulnerability of oases forest, whereas other factors receive much less attention. Here we argue that ecological and hydrological processes creating spatial habitat heterogeneity and particularly the change of habitat structure through time are critical aspects when assessing vulnerability of oasis forest. This is demonstrated by dendroecological studies of a dynamic landscape in Ejina Oasis in the lower reach of Heihe River, the second largest inland river in China. Our results show that radial growth of euphrates poplar trees in Ejina Oasis did not follow the variation of streamflow coming from the middle reach, and the poplar tree-ring growth did not change in the same way from one site to the other. An index of multi-directional change (MDCi) is defined from tree-ring data to describe the change in spatial habitats through time. We propose that the decreasing trend of MDCi indices since the 1950s is related to persistently increasing human activities, whereas high-frequency variability in MDCi indices is related to frequent and strong local disturbances such as windstorms as well as human activities that directly cause changes in streamflow. The results obtained from this study have potentially broad implications for identifying dryland ecosystems that are at risk or susceptible to change, and for making spatially explicit decisions for rational utilization of water resources.     

Ontogenetic Development of the Digestive System in Agastric Chinese Sucker,Myxocyprinus asiaticus,Larvae

This study was conducted to determine the ontogenetic development of the digestive tract and its accessory structures (liver, pancreas, and gall bladder) in agastric larval Chinese sucker Myxocyprinus asiaticus with the histological and ultrastructural approaches from hatching to 56 days after hatching (DAH). On the basis of its feeding mode, and analyzing the main histological features of the digestive system, larval development in Chinese sucker was divided into three stages from hatching: stage 1 (endotrophic period): 1–6 DAH; stage 2 (endoexotrophic period): 7–14 DAH; stage 3 (exclusively exotrophic period): from 15 DAH onward. At hatching, the digestive tract of the larvae consisted of an undifferentiated straight tube. At 4 DAH, the mouth opened, and the digestive tract was differentiated into buccopharyngeal cavity, esophagus and intestine. At 7 DAH, fish started to feed exogenously. Yolk sac was completely exhausted at 15 DAH. Until 56 DAH, the digestive tract of the larvae displayed regularly arranged microvilli, abundant vacuoles, and protein inclusion bodies. The pancreas, liver, and gall bladder were functional from 6 DAH, which enabled larvae to ingest, digest, and assimilate the first exogenous food. In comparison with teleosts that have a stomach, the development of the digestive tract of the agastric Chinese sucker seemed relatively slow .     

爆炸伤经海水浸泡动物模型的建立及伤口组织生化指标变化

以小型点暴源固定于大鼠的臀部,直流电源引爆,伤后将大鼠随机分为海水浸泡组和单纯爆炸伤组.将浸泡组大鼠置于人工配制的海水中30 min,于伤前及伤后1、3、7、10 d各处死10只大鼠,对伤口及周围组织进行取材,测定超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量、Na+-K+-ATP酶活力和Ca2+-Mg2+-ATP酶活力.单纯爆炸伤组除不浸泡海水外,处理同海水浸泡组.超氧化物歧化酶(SOD)活力,与创前相比,单纯爆炸伤组与创后1、3d活力降低(P<0.01),海水浸泡组在创后7 d活力降低(P<0.05).组间比较无差异.丙二醛(MDA)含量,与创前相比,单纯爆炸伤组创后1 d含量下降(P<0.01),但创后10 d升高(P<0.01).组间比较,海水浸泡组各时间点的含量均减少(P<0.05,P<0.01).与创前比较,海水浸泡组Na+-K+-ATP酶活力,在创后1 d升高(P<0.05),组间比较也升高(P<0.05).其他时间点组间比较无差异.与创前比较,单纯爆炸伤组创Ca2+-Mg2+-ATP酶活力创伤后1 d含量下降(P<0.01),但创后10 d显著升高(P<0.01);而海水浸泡组则在1、3、7、10 d时酶活力显著降低(P<0.01).组间比较,海水浸泡组在各时间点酶活力均显著降低(P<0.01).当爆炸伤仅伤及肌组织并经海水浸泡时,初期(1 d内)组织酶活性变化大,中期(3～10 d)有一定的变化,10 d以后趋于正常.     

RNA干扰技术在蜱研究中的应用

蜱是仅次于蚊子的第二大疾病传播媒介,分布广泛,对人和动物的健康危害严重。RNA干扰技术已经成功应用于新秀丽小杆线虫、黑腹果蝇、真菌及哺乳动物等方面的研究。本文就蜱体内RNA干扰的机理,RNA干扰方法以及在鉴定蜱基因功能、疫苗抗原筛选以及蜱与蜱传病原体的相互作用研究上的应用进行综述分析,探讨存在的问题和进一步应用前景。     

大果优质草莓引种研究初报

本文引入国内其它单位选育或引入的大果优质草莓新品种，进行了主要性状的观察记载，结果表明：在广州气候条件下，弗吉利亚，美丰，哈尼，丰香表现最好，全明星表现一般，硕蜜，９３０４两个品种基本不适应广州地区栽培。     

森林资源管理的遥感技术应用研究

本文论述了森林资源管理的遥感技术应用方法和手段。通过对不同时期的ＴＭ卫星影像进行数字解译处理，结合地面调查数据，计算各种图像指数，并辅以地理信息系统的分析，在ＥＲＤＡＳＩＭＡＧＩＮＥ和ＡＲＣ／ＩＮＦＯ系统的支持下，实现对森林资源动态变化情况进行监测的系列化程序，建立适用于福建省森林资源管理的遥感应用解析模型。     

化学诱变的BmNPV对家蚕细胞和虫体感染性的初步研究

前文报道化学诱变剂对家蚕核型多角体病毒 (BmNPV)多角体形态有明显的诱变作用 ,诱变的BmNPV基因组对某些限制性内切酶的酶切电泳谱发生变化。本文研究进一步表明 :诱变BmNPV感染家蚕Bm N细胞的病变特征与对照相比没有明显不同 ,但形成不定形超大多角体的空斑时间延迟2～ 3d;诱变BmNPV感染家蚕幼虫后 ,病蚕体内各组织病变损害的感染程度 (易感性 )与对照基本相同。研究结果提示 ,诱变的BmNPV对家蚕培养细胞、虫体组织的感染性无显著变化