外源基因在E.coli和Yeast中高效表达的理论

依据Ｅ．ｃｏｌｉ和Ｙｅａｓｔ基因表达水平与同义密码子使用，密码子内部碱基关联以及相邻密码子之间碱基关联的相关性，引入参数ＣＤＩ和ＣＥＩ分别代表密码子内部碱基关联与相邻密码子之间碱基关联对基因表达水平的影响，提出了一个通过ＣＤＩ和ＣＥＩ的极大化改造外源基因使之在Ｅ．ｃｏｌｉ和Ｙｅａｓｔ中高效表达的方案，并以鱼抗冻蛋白基因为例进行了具体计算。     

Landscape ecological evaluation on the artificial forest of <Emphasis Type="Italic">Leucaena leucocephala</Emphasis>

Based on the theory of ecology, this article conducted a landscape ecological evaluation on Leucaena leucocephala artificial forest in the add-hot valley, Yuanmou Xiaokua hill, using a combination method of qualitative analysis and landscape comprehensive evaluation. The comprehensive evaluation indexes of landscape include forest coverage, biodiversity, stability, soil erosion, environmental quality, availability, scientific research characteristic, economic benefits. Using AHP （analytical hierarchy process）, determine the grade of ecological evaluation factors and the weight of evaluation index and calculate the CEI （comprehensive evaluation index） on ecological evaluation. Evaluation results showed that the area CEI was 0.714 225, a better quality of the ecological level, but biodiversity indicators was the lowest. To sum up, it was difficult to maintain ecological restoration effectiveness and process but also guarantee a good biodiversity in the add-hot valleys. We must reasonably arrange the alien species and the native species, in order to obtain a stable and sustainable eco-system.