positive selection

Red color showed positive selection to most bird species .

红色果实在大部分鸟种中得到正选择。

The MHC restriction of T cell is determined in positive selection .

胸腺细胞的发育要经历阳性选择和阴性选择。

Evaluating effect of CD _ ( 34 ) positive selection with the graft cell - model

用移植物细胞模型评价CD（34）~+细胞选择的效果

Objective : To develop a selective system for positive selection of lac ⅰ mutants .

目的：建立一种能正向选择lacⅠ靶基因突变子的选择系统。

Advances in detecting positive selection on genome

DNA水平上检测正选择方法的研究进展

Establishment of Positive Selection System of Mannose and Application of Genetic Transformation in Arabidopsis thaliana

甘露糖正向筛选体系的建立及在拟南芥遗传转化中的应用

Results Two mannitol-tolerant cell lines were obtained from the embryogenic calli using positive selection method .

以所得到的胚性愈伤组织为起始材料，采用一步和多步正筛选法离体筛选耐甘露醇变异细胞系。

There was no significant positive selection pressure in the genes of the 3 virulence-associated factors .

经过检测这三个毒力相关因子的基因上都不存在显著的正选择压力。

Moreover , the time and labor-consuming tissue culture and positive selection steps can be avoided .

该表达体系无需进行植物组织培养和阳性植株筛选，可以节省大量的时间和人力。

Positive selection and vaccine mechanism are introduced on the premise of negative selection and clone selection in this algorithm .

该算法在负选择和克隆选择的基础上加入了阳性选择算子和疫苗算子。

In the human lineage , which was caused by Darwinian positive selection , was observed .

6在人这一支由于受到达尔文正向选择的作用而表现出快速进化的趋势；

About one third of the sequences under positive selection for the three sponges were related to multicellular process .

在三种海绵受到正选择压的基因中，约有1/3的序列与多细胞化基因相关。

Immunomagnetic positive selection of cd_ ( 34 ) ~ + progenitor cells from human cord blood

应用免疫磁珠法分离脐血CD（34）~+造血细胞

The main operators of the algorithm include positive selection , memory cells producing , hyper-mutation and similar antibodies suppression .

算法的主要算子包括正选择、记忆细胞产生、超变异和抗体相似性抑制。

We also found that many schistosome genes were under the pressue of purifying selection and few were under positive selection .

我们还发现大量的血吸虫基因处于纯化选择压力之下，而少数基因则处于正选择压力下。

These results provide evidences that positive selection is one of the main mechanisms in maintaining DRB gene polymorphism of the two species . 3 .

因此，正选择作用可能是维持这两种动物DRB基因多态性的主要机制之一。

Results also showed that the evolution of influenza B virus was under both strong positive selection and negative selection , which was contrary to previous reports .

结果还提示，乙型流感病毒的演变同时受到很强的正选择与负选择的作用，而以前人们认为选择对乙型流感病毒的演变作用甚微。

The codon-substitution and maximum likelihood models were used to detect positive selection effect among sites and analyze the molecular adaptive evolution of transferrins .

利用密码子替换模型和最大似然法模型，检测位点间的正选择作用并分析了转铁蛋白分子适应性进化。

On one hand , purer stem cells could be obtained with combined selection than single positive selection since double selection could distinguish stem cells from their progenies .

双标复合分选策略可以区分干细胞和它的子代细胞，比单标阳性分选获得的干细胞纯度更高。

These differences suggest that independent evolutionary events may have occurred in target sequences of two cultivated rice populations and stronger positive selection acted on japonica .

这些差异表明，在进化过程中粳稻和籼稻的靶序列发生了独立的进化事件，而且粳稻群体受到了更强的近期正选择作用。

The MHC restriction of T cell is determined in positive selection . The tolerance of T cells to autoantigen is acquired during negative selection .

阳性选择决定了成熟T细胞的MHC限制性，阴性选择使机体获得自身免疫耐受。

The " out - walk " strategy is the positive selection for China to grasp opportunities of world economic development and to improve the level of openness to the outside .

走出去战略是我国抓住世界经济发展机遇和提高对外开放水平的必然选择，对我国经济发展将产生深远的积极影响。

The Ka / Ks value of the duplicates was significantly greater than 1 , indicating that GAGE family is under positive selection .

用两种方法计算了GAGE各拷贝间的Ka/Ks值，结果为显著大于1，表明该基因家族受到正选择作用。

It has not been detected any positive selection sites by adaptive evolutional analysis , therefore Annexin A4 are highly conserved and undergoing strong functional constraint .

适应性进化分析没有检测到正选择位点，表明Annexina4非常保守，受到强烈的功能约束。

However , core sites of the functional CArG elements evolved faster than that of background DNA . This may hint that these two sites under positive selection .

但是功能CArG元件的中心位点5和位点6却显示出比背景序列高的替换率，这一结果预示着这两个位点可能承受着正向选择压力。

Applicants who have received a positive selection decision have received or will be receiving shortly a letter informing them they have been provisionally accepted .

有接受肯定的选择决定的申请者有收到或不久将会收到信告知他们有暂时的被接受的他们。

Antimicrobial peptides ( AMPs ) are highly polymorphic molecules . The diversity is originated from mechanisms such as focal mutation , positive selection and balanced selection .

两栖类抗菌肽具有高度多样性，这种多样性是通过定点突变、正选择、平衡选择等多种机制来产生和维持的。

The polymorphisms in the spike ( S ) protein showed a strongest positive selection for an initial infection , subsequent purifying selections , and eventual stabilization .

蛋白在发病早期受到最大的正向选择压力，然后逐步稳定下来。

Positive selection and vaccine mechanism are introduced on the premise of negative selection and clone selection . And a strategy of DNA PRI in the detection is adopted by using gene detection .

该算法综合了生物免疫系统的先天性免疫和适应性免疫机制，在负选择和克隆选择的基础上又加入了阳性选择和疫苗机制，并利用基因检测实现了检测的DNA优先级策略。

And in East Asians , they found strong evidence of positive selection in genes involved in the production of alcohol dehydrogenase ( ADH ), a protein necessary for breaking down alcohol .

科学家在中东人体内的乙醇脱氢酶中也发现了积极选择的证据。这种酶能够快速瓦解酒精。