A genomic view of alternative splicing.

Recent genome-wide analyses of alternative splicing indicate that 40-60% of human genes have alternative splice forms, suggesting that alternative splicing is one of the most significant components of the functional complexity of the human genome. Here we review these recent results from bioinformatics studies, assess their reliability and consider the impact of alternative splicing on biological functions. Although the 'big picture' of alternative splicing that is emerging from genomics is exciting, there are many challenges. High-throughput experimental verification of alternative splice forms, functional characterization, and regulation of alternative splicing are key directions for research. We recommend a community-based effort to discover and characterize alternative splice forms comprehensively throughout the human genome.     

Characterization and relative abundance of maxi-chloride channels in Epstein-Barr virus (EBV) producer: B95-8 cells

Several Epstein-Barr virus (EBV)-transformed cell lines were used to investigate the pathogenesis of lymphoproliferative diseases and nasopharyngeal carcinoma. The studies focus on the events occurring inside the membrane. On only one occasion, the cell membrane of EBV-transformed B lymphocytes from a cystic fibrosis patient was found to express defective Cl channels (CFTR; Cystic Fibrosis Transmembrane conductance Regulator), as in the airway epithelial cell. No other type of channel in EBV-transformed cells has so far been investigated. In this study, the cell membrane of the B95-8 cell was examined by the patch-clamp technique and compared to the non-EBV-infected BJAB cell. The high conductance (300 pS) maxi-chloride (Cl) channel activity was the most frequently observed event in inside-out configurations. Under similar experimental conditions, we have found a significantly higher probability of detecting maxi-Cl channel activity on the cell membrane of B95-8 cells (69%) than on BJAB cells (27%), or as previously reported on resting murine B lymphocytes (38%) or intact human T lymphocytes (37%). The relative abundance of the maxi-Cl channel on B95-8 cells may be linked to EBV infection and/or secretory ability.     

On Classification and Regression Trees for Multiple Responses and Its Application

In many application fields, multivariate approaches that simultaneously consider the correlation between responses are needed. The tree method can be extended to multivariate responses, such as repeated measure and longitudinal data, by modifying the split function so as to accommodate multiple responses. Recently, researchers have constructed some decision trees for multiple continuous longitudinal response and multiple binary responses using Mahalanobis distance and a generalized entropy index. However, these methods have limitations according to the type of response, that is, those that are only continuous or binary. In this paper, we will modify the tree for univariate response procedure and suggest a new tree-based method that can analyze any type of multiple responses by using GEE (generalized estimating equations) techniques. To compare the performance of trees, simulation studies on selection probability of true split variable will be shown. Finally, applications using epileptic seizure data and WWW data are introduced.     

微波消解-电感耦合等离子体质谱测定沉积物中的金属元素

采用不同的微波消解程序和不同混合酸消解近海沉积物标准参考物(GBW0 7314 ) ,用ICP -MS测定16种金属元素(Al,Ba ,Cd ,Co ,Cr,Cu ,Fe ,K ,Mn ,Mo ,Ni,Pb ,V ,Zn ,Ca和Mg)的含量.依据回收率,比较了消解程序、混合酸组成、用量对GBW0 7314的消解效果.结果表明,由6mLHNO3 - 2mLHF/2mLH2 O2 组成的混合酸对沉积物具有很好的消解能力,微波加热2 0min能迅速有效消解沉积物;除Al外,GBW 0 7314中各元素的测定值与推荐值相符     

薄层色谱指纹图谱在丹参药材质量评价中的应用研究

利用薄层色谱（TLC）技术对中药材丹参的有效成分进行了指纹图谱分析．以不同等级的中江丹参和不同采收期的丹参、南丹参为分析对象，采用适宜的水溶性及脂溶性成分提取方法和TLC分析条件，可获得其相应的TLC图像及色谱图．通过对不同丹参药材的色谱图像的分析，结合化学计量学方法对其各主要指标成分的信息进行提取，初步构建了丹参的TLC指纹图谱．结果表明，在254nm波长下获取脂溶性和水溶性成分共7个共有指纹峰，各峰相对比移值（R1）和峰面积的相对标准偏差分别小于1．7％和4．0%．通过对薄层色谱斑点的RI值、斑点颜色和大小的比较。并进行主成分分析和聚类分析，实现了对不同等级的丹参进行归属，并确立了最佳采收期．本实验建立的薄层色谱指纹图谱方法具有较高的稳定性、良好的精密度和重现性，可用于丹参药材的质量评价和控制．     

FFT and PLL based GPS signal processing for Software GPS Receiver

This paper presents FFT and PLL based GPS signal acquisition and tracking algorithms for a software GPS receiver. Conventional hardware based acquisition and tracking have some restrictions in processing signal with poor signal to noise ratio. The FFT of digitized local signals of multiple carrier frequencies for a specified Doppler band are pre-computed and are circular correlated with the digitized incoming signal from RF-front-end in an organized computational order. The global maximum of the correlation is associated with the closest estimates of the Doppler shift and the code shift. PLL refines the estimates to track the signal. Doppler information from an external source can readily be integrated to narrow down the frequency band for correlation and is especially useful for tracking in a high dynamic navigation situation. The performance of the proposed algorithms is evaluated through post processing of the IF signals acquired from a commercial hardware GPS receiver.     

马立克氏病病毒meq基因功能研究

从马立克氏病病毒（MDV）不同致病型毒株meq基因序列，meq基因产物及其细胞内表达特性和meq蛋白生物学功能的研究探讨马立克氏病病毒致瘤基因meq功能。完成了648A,CV1988/Rispens,814，广西地方毒株G2，N，0093，0095，0297，0304共9个MDV毒株meq基因的序列测定。MDV不同致病型毒株的meq基因序列相对比较保守，它们相互间核苷酸和氨基酸序列的同源性均很高；与所有7个致瘤的MDV毒株相比，在2个MDV-1弱毒疫苗CV1988/Rispens株和814株发现有二个特征性位点突变。此外，还在其ORF中首次发现含15个氨基酸残基（EELCAQLCSTPPPPI）的2个重复和含6个氨基酸残基（PPICTP）的4个重复，全分布在MEQ蛋白C-端的转录激活域内。MEQ蛋白的表达仅局限于感染细胞的核内，而且随感染时间增加。具有从核质向核仁和核膜转移趋向；Western Blotting和免疫沉淀试验证实重组杆状病毒感染细胞裂解物中有大小约为60kD的特异带，利用表达的MEQ蛋白产物免疫BALB/c小鼠，获得的杂交瘤细胞被克隆并与MDV感染的鸡胚成纤维细胞（CEF）做免疫荧光试验（FA），获得4株稳定产生抗MEQ蛋白单克隆抗体（McAb)的杂交瘤细胞，其中3G12E6单克隆抗体能够检测到MDV致瘤株感染的CEF及自然MD肿瘤细胞中表达的meq基因产物，而CV1988/Rispens感染的细胞则未检测到，发现细胞内表达的meq基因产物可明显促进MDVGA株对体外培养细胞的感染及增殖。研究结果表明，meq基因在感染细胞内的表达水平是MDV增殖和致病，致瘤的分子基因。     

岩爆的剪切滑移机理分析

在讨论地下围岩应力分布的基础上,用滑移线场理论和Ｍｏｈｒ－Ｃｏｕｌｏｍｂ准则研究了地下洞室围岩进入塑性破坏状态的特征,推导了岩块沿滑移线滑落的条件,得到了岩爆发生时地应力的计算公式．对天生桥引水隧洞的岩爆实例进行了分析和计算,得到了较满意的结果．     

Lipid droplets of neuroepithelial cells are a major calcium storage site during neural tube formation in chick and mouse embryos

In situ precipitation of calcium (Ca²⁺) with fluoride and antimonate shows that Ca²⁺-specific precipitate is localized almost exclusively within lipid droplets of neuroepithelial cells during neural tube formation in chick and mouse embryos. The density of Ca²⁺ precipitate within lipid droplets is generally greater in the apical ends of cells situated in regions of the neuroepithelium that are actively engaged in bending. These findings suggest that lipid droplets, in addition to providing a source of metabolic fuel for developing neuroepithelial cells, also serve as Ca²⁺-storage and-releasing sites during neurulation.This study was supported by grants from the NIH (NS23200), the BRSG fund of UMDNJ, and the Busch Fund of Rutgers University. Dr Bush was supported by a New Jersey State Postdoctoral Fellowship.