Multidrug-Resistant Transport Proteins in Yeast: Complete Inventory and Phylogenetic Characterization of Yeast Open Reading Frames within the Major Facilitator Superfamily

Screening of the complete genome sequence from the yeast Saccharomyces cerevisiae reveals that 28 open reading frames (ORFs) are homologous to each other and to established bacterial members of the drug-resistant subfamily of the major facilitator superfamily. The phylogenesis of these protein sequences shows that they fall into three major clusters. Cluster I contains 12 ORFs, cluster II contains ten ORFs and cluster III contains six ORFs. Hydropathy analyses indicate that in clusters II and III ORFs, 14 transmembrane spans are predicted whereas only 12 transmembrane spans are predicted in cluster I ORFs. Three ORFs that have known functions as multidrug-resistance pumps in other yeast species such as Schizosaccharomyces pombe (CAR1), Candida albicans (BMRP) or C. maltosa (CYHR), also fall into cluster I. Two S. cerevisiae ORFs of known multidrug-resistance function (ATR1, SGE1) fall into cluster II. Cluster III consists exclusively of ORFs of unknown function but binary sequence comparisons show homology to ORFs from cluster II. Analysis of the multiple alignment for these proteins leads to the identification of characteristic signature sequences for each of the three clusters. © 1997 by John Wiley & Sons, Ltd.     

A method of fundamental solutions for radially symmetric and axisymmetric backward heat conduction problems

We propose and investigate an application of the method of fundamental solutions (MFS) to the radially symmetric and axisymmetric backward heat conduction problem (BHCP) in a solid or hollow cylinder. In the BHCP, the initial temperature is to be determined from the temperature measurements at a later time. This is an inverse and ill-posed problem, and we employ and generalize the MFS regularization approach [B.T. Johansson and D. Lesnic, A method of fundamental solutions for transient heat conduction, Eng. Anal. Boundary Elements 32 (2008), pp. 697–703] for the time-dependent heat equation to obtain a stable and accurate numerical approximation with small computational cost.     

一种基于矩阵的多值关联规则的挖掘算法

关联规则是数据挖掘研究的主要模式之一,其中布尔型关联规则的挖掘已经有比较成熟的系统和方法,而多值关联规则的挖掘则不然。本文提出的QARMM算法利用矩阵存储数据,将频繁项目集的产生过程转化为项目集的关系矩阵中向量的运算过程,同时克服了SLIG算法和矩阵算法不能挖掘多值关联规则的弱点,只需运行一次便可挖掘出所有关联规则。实验证明,在等价的数据集上挖掘关联规则,QARMM算法比Apriori算法具有更高的效率。     

An inverse analysis method for design optimization with both statistical and fuzzy uncertainties

If the statistical data for the input uncertainties are sufficient to construct the distribution function, the input uncertainties can be treated as random variables to use the reliability-based design optimization (RBDO) method; otherwise, the input uncertainties can be treated as fuzzy variables to use the possibility-based design optimization (PBDO) method. However, many structural design problems include both input uncertainties with sufficient and insufficient data. This paper proposes a new mixed-variable design optimization (MVDO) method using the performance measure approach (PMA) for such design problems. For the inverse analysis, this paper proposes a new most probable/possible point (MPPP) search method called maximal failure search (MFS), which is an integration of the enhanced hybrid mean value method (HMV+) and maximal possibility search (MPS) method. This paper also improves the HMV+ method using an angle-based interpolation. Mathematical and physical examples are used to demonstrate the proposed inverse analysis method and MVDO method.     

基于CORBA的可集成MES的研究

文章介绍了MES的内涵和产生的原因,并在分析了MES可集成的必要性的基础上,提出了基于c0RBA的可集成MES的技术方案,而且详细阐述了该MES的体系结构、所涉及的关键技术以及实现方法.     

群集环境下的直接文件系统访问

介绍一种强制进程转移的群集计算环境 (MOSIX)及可升级的、负荷平衡的直接文件访问 (DFSA)机制。并对DFSA的第一个原型MOSIX文件系统 (MFS)的特点、原理作了说明     

An Alternating Iterative MFS Algorithm for the Cauchy Problem in Two-Dimensional Anisotropic Heat Conduction

In this paper, the alternating iterative algorithm originally proposed by Kozlov, Maz'ya and Fomin (1991) is numerically implemented for the Cauchy problem in anisotropic heat conduction using a meshless method. Every iteration of the numerical procedure consists of two mixed, well-posed and direct problems which are solved using the method of fundamental solutions (MFS), in conjunction with the Tikhonov regularization method. For each direct problem considered, the optimal value of the regularization parameter is chosen according to the generalized cross-validation (GCV) criterion. An efficient regularizing stopping criterion which ceases the iterative procedure at the point where the accumulation of noise becomes dominant and the errors in predicting the exact solutions increase, is also presented. The iterative MFS algorithm is tested for Cauchy problems related to heat conduction in two-dimensional anisotropic solids to confirm the numerical convergence, stability and accuracy of the method.     

Novel LOX Variants in Five Families with Aortic/Arterial Aneurysm and Dissection with Variable Connective Tissue Findings

Thoracic aortic aneurysm and dissection (TAAD) is a major cause of cardiovascular morbidity and mortality. Loss-of-function variants in LOX, encoding the extracellular matrix crosslinking enzyme lysyl oxidase, have been reported to cause familial TAAD. Using a next-generation TAAD gene panel, we identified five additional probands carrying LOX variants, including two missense variants affecting highly conserved amino acids in the LOX catalytic domain and three truncating variants. Connective tissue manifestations are apparent in a substantial fraction of the variant carriers. Some LOX variant carriers presented with TAAD early in life, while others had normal aortic diameters at an advanced age. Finally, we identified the first patient with spontaneous coronary artery dissection carrying a LOX variant. In conclusion, our data demonstrate that loss-of-function LOX variants cause a spectrum of aortic and arterial aneurysmal disease, often combined with connective tissue findings.     

Regularized meshless method for antiplane shear problems with multiple inclusions

In this paper, we employ the regularized meshless method to solve antiplane shear problems with multiple inclusions. The solution is represented by a distribution of double‐layer potentials. The singularities of kernels are regularized by using a subtracting and adding‐back technique. Therefore, the troublesome singularity in the method of fundamental solutions (MFS) is avoided and the diagonal terms of influence matrices are determined. An inclusion problem is decomposed into two parts: one is the exterior problem for a matrix with holes subjected to remote shear, the other is the interior problem for each inclusion. The two boundary densities, essential and natural data, along the interface between the inclusion and matrix satisfy the continuity and equilibrium conditions. A linear algebraic system is obtained by matching boundary conditions and interface conditions. Finally, numerical results demonstrate the accuracy of the present solution. Good agreements are obtained and compare well with analytical solutions and Gong's results. Copyright © 2007 John Wiley & Sons, Ltd.     

Coupling of the BEM with the MFS for the numerical simulation of frequency domain 2-D elastic wave propagation in the presence of elastic inclusions and cracks

This paper proposes a coupling formulation between the boundary element method (BEM displacement and TBEM traction formulations) and the method of fundamental solutions (MFS) for the transient analysis of elastic wave propagation in the presence of multiple elastic inclusions to overcome the specific limitations of each of these methods. The full domain of the original problem is divided into sub-domains, which are handled separately by the BEM or the MFS. The coupling is enforced by imposing the required boundary conditions.The accuracy, efficiency and stability of the proposed algorithms, using different combinations of BEM and MFS, are verified by comparing the solutions against reference solutions. The computational efficiency of the proposed coupling formulation is illustrated by computing the CPU time and the error at high frequencies.The potential of the proposed procedures is illustrated by simulating the propagation of elastic waves in the vicinity of an empty crack, with null thickness placed close to an elastic inclusion.