Gene network shaping of inherent noise spectra

Recent work demonstrates that stochastic fluctuations in molecular populations have consequences for gene regulation. Previous experiments focused on noise sources or noise propagation through gene networks by measuring noise magnitudes. However, in theoretical analysis, we showed that noise frequency content is determined by the underlying gene circuits, leading to a mapping between gene circuit structure and the noise frequency range. An intriguing prediction from our previous studies was that negative autoregulation shifts noise to higher frequencies where it is more easily filtered out by gene networks--a property that may contribute to the prevalence of autoregulation motifs (for example, found in the regulation of approximately 40% of Escherichia coli genes). Here we measure noise frequency content in growing cultures of E. coli, and verify the link between gene circuit structure and noise spectra by demonstrating the negative autoregulation-mediated spectral shift. We further demonstrate that noise spectral measurements provide mechanistic insights into gene regulation, as perturbations of gene circuit parameters are discernible in the measured noise frequency ranges. These results suggest that noise spectral measurements could facilitate the discovery of novel regulatory relationships.     

Trends in A8 migration to the UK during the recession

A substantial proportion of contemporary migration flows to the UK are made by nationals from countries which have recently joined the EU. The nature of A8 migration during the recession is examined in this paper, mainly using data from the Worker Registration Scheme. The recession has seen a decline in new A8 migrants entering the UK labour market, but the decline has been sectorally uneven, with demand for migrant labour being most persistent in the agricultural sector, raising questions about why this part of the UK economy is so different.     

软岩注浆预加固技术在公路隧道中的应用

文章对软岩的结构特征与分类、注浆加固机理进行了介绍,对公路隧道软岩施工中的超前小导管注浆加固技术,从加固机理、注浆必要性、施工工艺等方面作了阐述.     

DPOAE信号时域分解算法的窗宽选择

研究畸变产物耳声发射(DPOAE)产生源机制常用分解方法,针对实验分解方法干扰多、实验量大的特点,该文提出基于小波分解的互相关和基于DPOAE时域能量分布的窗宽选择算法进行时域分解.通过强化不同成分分界点,加窗提取相位特征不同的信号成分.结果与实验方法进行对比,表明算法实现了DPOAE的准确分解,其效果与实验加最佳抑制声时结果相似,同时避免了干扰、减少了实验量.该方法为DPOAE产生源机制的研究提供了更方便、准确的研究工具.     

关于我国网络银行发展的思考

文章从网络银行的优势入手,分析了网络银行在我国的发展现状,提出了从控制风险、市场定位、服务特点和发展模式发展网络银行的观点.     

Cells compete for decapentaplegic survival factor to prevent apoptosis in Drosophila wing development

During the growth of Drosophila imaginal discs a process called 'cell competition' eliminates slow-proliferating but otherwise viable cells. We report here that cell competition requires the function of the brinker (brk) gene, whose expression is normally repressed by Decapentaplegic (Dpp) signalling but is upregulated in slow-growing Minute/+ cells. Excess brk expression activates the c-Jun amino-terminal kinase pathway, which in turn triggers apoptosis in these cells. We propose that slow-proliferating cells upregulate Brk levels owing to a disadvantage in competing for, or in transducing, the Dpp survival signal. This sequence of events might represent a general mechanism by which weaker cells are eliminated from a growing population, and might serve as a method of controlling cell number and optimizing tissue fitness and hence organ function.     

新的H2O脉泽源的发现与证认

用紫金山天文台青海站的１３．７ｍ射电望远镜对一批强ＩＲＡＳ远红外源进行了Ｈ２Ｏ脉泽谱线的搜寻，发现了１０个新的Ｈ２Ｏ脉泽源。其中９个源均与恒星形成区成协，它们是正在形成中的大质量星的标志，另一个则是著名的富碳星ＩＲＣ１０２１６，在富碳星包层中Ｈ２Ｏ脉泽活动的出现是罕见的。还讨论了这些新发现源的演化特性和时变特性。     

Chemical glycosylation in the synthesis of glycoconjugate antitumour vaccines

Therapeutic vaccines derived from carbohydrate antigen-adjuvant combinations are a promising approach for cancer immunotherapy. One of the critical limitations in this area is access to sufficient quantities of tumour-associated carbohydrate antigens and glycoconjugate adjuvants. At present, availability of the complex oligosaccharide constructs that are needed for the systematic design and evaluation of novel vaccine formulations relies on de novo chemical synthesis. The use of both state-of-the-art and emerging glycosylation technologies has led to significant advances in this field, allowing the clinical exploration of carbohydrate-based antigens in the treatment of cancer.     

几何—算术平均不等式的两种归纳证明

对几何—算术平均不等式给出两种初等的归纳证明。