雏鹅新型病毒性肠炎病毒弱毒株的培育及其特性研究

应用在鸭胚成纤维细胞上连续传代的方法 ,获得了由雏鹅新型病毒性肠炎病毒强毒株(NGVEV CN株 )致弱的弱毒株 (CN4 0 株 )。该弱毒株TCID50 为 10 - 8.0 83,具有良好的安全性和稳定性 ,在易感 1日龄雏鹅连传 8代不返强。该弱毒具有良好的免疫原性 ,最小免疫剂量为 10 0 0 0TCID50 ,免疫后 3d产生部分免疫力 ,5d产生坚强免疫力。口服免疫效果最好 ,对雏鹅免疫期在30d以上。该弱毒株能够干扰强毒在雏鹅体内繁殖 ,进入鹅体后能够进行一定程度繁殖并排泄出体外 ,使同居雏鹅感染并获得一定程度免疫力。临床使用后可极显著降低雏鹅的死亡率。     

Displaying the Law: A Cross-disciplinary Learning Experiment Using the Internet and Multimedia Technology

The law is increasingly being displayed to its practitioners and subjects in new forms and through new media. Some of this technological change simply permits easier access to information and faster recording processes. However students are at the forefront of the attempt to provide new ways of representing legal dilemmas, problems and issues. How do students imagine and represent the law? This paper describes an experiment in which undergraduate students from quite different backgrounds examined topical legal issues and presented reports in visual form, choosing between three formats: CD-ROMs, videos and web pages. Participants came from two universities in Victoria; students from Victoria University were multimedia students, students from the University of Melbourne were criminology research methods students. They formed small teams, pooling their skills to carry out research projects on aspects of the law, including busking, football violence and how images of blood should be shown on film or TV. This article reviews the lessons of this collaborative exercise for understandings of the law.     

高科技与新的教育革命

现行教育是工业化的一部分,贯彻的是工业明的基本原则,高度的标准化、专业化、集中化和同步化,这在许多方面违背人才成长的规律。高科技的发展和推广必然会引起新的教育革命,对劳动的素质提高了新的要求,并提出了崭新的教学手段,逐步使群体教育转化为个性教育,使刚性教育转化为柔性教育,能更好地培养学生的个性和创造