Three Rs and Five Freedoms

The Three Rs tenet (Replacement, Reduction and Refinement) guides scientists on the ethical use of animals in science.

  • Replacement refers to methods which avoid or replace the use of animals in an area where animals would otherwise have been used
  • Reduction refers to any strategy that will result in fewer animals being used
  • Refinement refers to the modification of husbandry or experimental procedures to minimize pain and distress

The Five Freedoms Are:

  1. Freedom from hunger and thirst (by ready access to fresh water and a diet to maintain full health and vigour).
  2. Freedom from discomfort (by providing an appropriate environment including shelter and a comfortable resting area).
  3. Freedom from pain, injury and disease (by prevention or rapid diagnosis and treatment).
  4. Freedom to express normal behaviour (by providing sufficient space, proper facilities and company of the animal’s own kind).
  5. Freedom from fear and distress (by ensuring conditions and treatment which avoid mental suffering).

related information:


  1. 安装U深度,U盘启动盘制作工具:
  2. 启动软件
  3. 选择配置:智能模式,HDD-FAT32,兼容模式,默认设置
  4. 选择好优盘,点击开始制作;(整个过程可能需要5到10分钟)
  5. 将之前下载好的系统镜像放到,GHO文件夹下;
  6. 重启电脑,选择从U盘启动,重启电脑;
  7. 选择“运行U深度Win03PE2013增强版”;
  8. 进入winpe系统后,会自动弹出对话窗口“U深度装机工具”,并检测出之前存放于U盘中的ghost系统;(Ghost系统是指通过赛门铁克公司(Symantec Corporation)出品的Ghost在装好的操作系统中进行镜像克隆的版本,通常GHOST用于操作系统的备份,在系统不能正常启动的时候用来进行恢复的。)
  9. 选择所要安装的硬盘分区,点击确定;
  10. 然后软件会,解压文件到选择的硬盘分区,然后重启电脑开始安装;