选择压力

Southern杂交分析表明若处于很强的选择压力下，该质粒的拷贝数会发生有效的扩增。

By means of southern hybridization analysis , the efficient amplification of plasmid copy number was detected under a strong selection pressure .

当以cat基因作为选择性标记基因时，氯霉素可以作为紫菜原生质体基因转化的选择压力。

Chloramphenicol could be used as selection pressure for positive transformant when cat gene was used as selectable marker gene .

HA基因受生存选择压力作用；

Genetic variation of HA gene is under survival selective pressure ;

目标产物经HPLC定性分析，确定为反式虾青素。因此，以辛伐他汀等HMG-CoA还原酶抑制剂作为选择压力，对虾青素高产突变株的筛选上具有较好的筛分能力。

The objective product identified by qualitative HPLC analysis was trans-astaxanthin .

它们通过一种称为遗传漂变（geneticdrift）的过程积累它们的DNA的突变，而且几乎没有抑制这些突变的选择压力。

They accumulate mutations in their DNA by a process known as genetic drift and there are few selection pressures around to curb these mutations .

植骨块的应力测试选择压力敏感胶片，分别置于A、B两组C4～C6与植入髂骨块之间，计算出其所受应力大小。

The contact stress of the implanted bone and cervical vertebrae was measured with the pressure-sensitive-film and a relevant measuring system .

结论MRSA的出现是高抗生素选择压力的结果；

CONCLUSIONS The emergence of MRSA is the result of high antibiotic selective pressure .

在疫苗免疫选择压力下H9N2亚型禽流行性感冒病毒HA基因的遗传变异

Genetic Mutations of the Hemagglutinin Gene of H_9N_2 Subtype Avian Influenza Viruses under the Selective Pressure of Vaccination

本文针对传统遗传算法存在种群多样性和选择压力之间矛盾的问题，提出一种基于自然界蜂群繁殖原理的改进遗传算法&蜂群遗传算法（Bee-SwarmGeneticAlgorithm，简称BSGA）。

Bee-Swarm genetic algorithm based on reproducing of swarm is proposed in this thesis , to solve the contradiction between population diversity and pressure of selection .

通过这些分析，希望能够深刻的了解这些MHC基因在鲸类的变异水平，尤其关注那些由选择压力引起的序列变异。

It is expected to have an in-depth understanding on the behavior of these molecules , especially sequence variability possibly caused by selection pressure .

不同的选择压力使得GI的进化速度相对较快，从而加速了黄山松和马尾松的物种分化。

Thus we speculate that GI ( control of flowering time ) may have experienced speciation-related selection , which further accelerated its lineage-sorting divergence between the species .

之后，这些小的反义RNA可能会在RNA拼接中发挥作用，如在选择压力下修复基因组中一个区域，抑或在丧失或损坏一个模块后恢复一个读码框。

Such small antisense RNAs may later have gained a role in RNA editing , possibly under selective pressure to repair a region or restore a reading frame after loss or erosion of a module .

ERIC（IRU）高度保守，可能其变异受到自然选择压力的限制或它本身就可能是自私的DNA。

ERIC ( IRU ) is highly conserved , for its variation is restricted by the natural selection pressure , or it 's " selfish DNA " .

早在查尔斯·达尔文（CharlesDarwin）的时代，对于家养动物的研究，就帮助拓展了人类对进化过程的认识，因为我们很清楚它们面临着怎样的选择压力。

As far back as Charles Darwin , domestic animals in particular have yielded insights about evolution because we know what sorts of selection pressures they were subject to .

因此得出结论，PRO基因可以广泛地用于构建在酿酒酵母中克隆和表达外源基因的载体，以便用丰富培基作为选择压力直接筛选。

Our data suggested that PRO genes might be used widely in constructing vectors to clone and express foreign genes in yeast so that rich medium can be used as a selection pressure for direct selection .

此外，在日本七鳃鳗中，三个Y-box基因也是受到净化选择压力作用（P0.05）。

In addition , the three Y-box genes in Japanese lamprey ( Lampetra japonica ) were also subject to purifying selection ( P0.05 ) .

矿浆中含有少量硫化矿，矿浆pH为1-3，在适合细菌生长的同时，由于矿浆中富含高浓度的无机盐和浮选药剂残留，对细菌有较大的选择压力。

The pulp is suitable for the bacterial growth due to a low quantity of sulfide minerals at pH 1-3 ; but it also has a great selection pressure on the bacteria due to high concentrations of inorganic salts and flotation reagent residue .

特别是在求解高维多目标优化问题时，基于Pareto占优机制导致算法的选择压力不够，导致算法的收敛速度缓慢甚至停滞。

Especially in solving many-dimensional multiobjective optimization problem , pressure is not enough , lead to the choice of algorithm based on Pareto dominant mechanism leading to the convergence speed is slow or even stagnation .

以NaCl作选择压力，将长期继代培养的葡萄愈伤组织经正选择方法筛选出耐0.75%NaCl的变异细胞系，并对其进行了生理生化特性研究。

A variant cell line of grape tolerant to 0.75 % NaCl is isolated from long term cultured calluses by using NaCl as selection pressure . The physiological and biochemical properties of this salt tolerant cell line are analyzed .

因此，在我国东南沿海地区要注意Btk制剂与Bt其他亚种制剂或其他生物杀虫剂轮换使用，以减小Bt制剂对小菜蛾的选择压力，延缓小菜蛾对Bt抗性的发展。

So , it was proposed that the rotations of Btk with other Bt subspecies or other kinds of bioinsecticides should be encouraged in order to delay resistance development of P. xylostella in southeastern China .

雄性质量模型（MaleQualityModel，MQ）和栖息地资源竞争模型（LocalResourceCompetitionModel，LRC）分别将这种现象发生的机制解释为物种对性选择压力和资源竞争压力的回应。

The Male Quality Model ( MQ ) and the Local Resource Competition Model ( LRC ) suggest that this phenomenon is a response to sexual selection and resource competition pressure , respectively .

经G418筛选，获得了G418抗性细胞P851-S，在G418选择压力下，已连续筛选80余天，传代12次；

By selection with G418 , G418 resistant cells ( P815-S ) were obtained , and were already selected under the pressure of G418 for more than 80 days , 12 generations continuously .

而且，我们的随机模拟分析表明，反转录假基因积累的突变不完全是随机的或者不受任何选择压力：它在突变中丢失的IRS要少于随机突变所丢失的IRS；

What 's more , the random mutation simulations show that , the mutation of retropseudogenes should not be regard as random or completely release from selective pressure : they discarded IRS is less than the situation of random mutation ;

同时，Wx基因表现出连锁不平衡现象，外显子2和内含子1区域所承受的选择压力较小。

At the same time , Wx gene showed the phenomena of linkage disequilibrium ( LD ) and exon 2 and intron 1 regions were subject to the least selection pressure in its entire gene sequence .

选择压力支持+呼气末正压（PSV+PEEP）、同步间歇指令+压力支持（SIMV+PSV）、压力控制（PCV）等通气模式。

The ventilate mode of pressure support and positive end-expiratory pressure ( PSV and PEEP ), synchronized intermittent mandatory ventilation and pressure support ( SIMV and PSV ), pressure control ( PCV ) were adopted .

根据蛋白质残基的功能重要性与自然选择压力相互关联的分子进化原理，对GDNF家族及其受体GFRα家族进行了进化踪迹分析，搜索到相互作用的功能决定位点。

Based on the principle of molecular evolution that site-specific functional importance is relevant to the pressure it undergoes under natural selection , evolutionary trace method was used to identify the functional epitopes in GDNF and GFR α families .

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。

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 .

由于自然选择压力，相互作用的蛋白质在进化过程中呈现出共进化的特征，因此提出co-Diad特征提取算法来表示两个蛋白质之间的共进化信息。

Since the pressure of natural selection , the interacting proteins are co-evolution during the process of evolution . Therefore , co-Diad feature is exploited for representing the co-evolution information between two proteins .

因此，进一步提高308R（pKK233-2-SZZ-hrpN）的遗传稳定性可以为将来在没有抗生素标记选择压力下，生防工程菌的大规模发酵制备和在田间长期稳定发挥抗病效果奠定基础。

The genetic stability of 308R ( pKK233-2-SZZ - hrpN ) is needed to improve in order to establish the foundation for large scale fermentation and long period and stable effect in the fields without the selection pressure of antibiotic markers .

我的妻子常常遗憾我没有选择压力小点的职业。

My wife often wishes I had chosen a less stressful career .