鲢(Hypophthalmichthys molitrix)IL-10基因的克隆及表达分析

白细胞介素10(IL-10)是一种作用广泛的抗炎细胞因子,主要功能是限制和最终终止炎症反应．用RACE(rapid amplification of cDNA ends)-PCR方法扩增出鲢白细胞介素10(IL-10)的 cDNA,其全长为1248nt,包含5’非编码区156 nt,3’非编码区552nt,开放阅读框540nt．鲢IL- 10的开放阅读框编码179个氨基酸,其中包含构成两对二硫键的4个保守半胱氨酸．RT-PCR结果显示鲢IL-10 mRNA主要在脾脏、鳃、头肾和肌肉中表达．将鲢IL-10完

鳜IL-1β基因的克隆及原核表达

用RACE PCR获得了鳜白介素-1β(IL-1β)的全长cDNA.鳜IL-1β的cDNA全长为1298 nt(核苷酸),其5′非编码区包含UTR 93 nt;3′非编码区包含452 nt;其开放阅读框内包含753 nt,翻译成251个氨基酸.将鳜IL-1β克隆到原核表达载体pET-32a上,在大肠杆菌Rosetta- gami(DE3)内以包涵体形式得以高效表达.

State estimation schemes for independent component coupled hidden Markov models

Conventional Hidden Markov models generally consist of a Markov chain observed through a linear map corrupted by additive noise. This general class of model has enjoyed a huge and diverse range of applications, for example, speech processing, biomedical signal processing and more recently quantitative finance. However, a lesser known extension of this general class of model is the so-called Factorial Hidden Markov Model (FHMM). FHMMs also have diverse applications, notably in machine learning, artificial intelligence and speech recognition [13, 17]. FHMMs extend the usual class of HMMs, by supposing the partially observed state process is a finite collection of distinct Markov chains, either statistically independent or dependent. There is also considerable current activity in applying collections of partially observed Markov chains to complex action recognition problems, see, for example, [6]. In this article we consider the Maximum Likelihood (ML) parameter estimation problem for FHMMs. Much of the extant literature concerning this problem presents parameter estimation schemes based on full data log-likelihood EM algorithms. This approach can be slow to converge and often imposes heavy demands on computer memory. The latter point is particularly relevant for the class of FHMMs where state space dimensions are relatively large. The contribution in this article is to develop new recursive formulae for a filter-based EM algorithm that can be implemented online. Our new formulae are equivalent ML estimators, however, these formulae are purely recursive and so, significantly reduce numerical complexity and memory requirements. A computer simulation is included to demonstrate the performance of our results. © Taylor & Francis Group, LLC.

草鱼、中华鳖脾细胞培养上清液IL-2物质的检测

用刀豆蛋白A(ConA)刺激诱导草鱼和中华鳖脾细胞 ,收集细胞培养上清液 ,用小鼠胸腺细胞增殖试验和对小鼠L92 9细胞系杀伤试验检测上清液中白细胞介素 2 (简称IL 2 )活性。结果表明 :草鱼、中华鳖脾细胞培养上清液中有IL 2样活性物质 ,这种物质使小鼠的胸腺细胞3H TdR掺入量明显增加 ,在相同效靶比的条件下对小鼠L92 9细胞系杀伤率也显著增强 ,这种IL 2活性均能被抗人rIL 2血清所抑制。中华鳖脾细胞培养上清液 (含IL 2 )对中华鳖胸腺细胞也有较明显的促增殖作用并能消除兔抗中华鳖胸

草鱼、中华鳖IL-2活性影响因素的研究

结果显示 :当年草鱼种和中华鳖脾细胞培养上清液中能检测出IL 2活性 ,而且 1龄以上草鱼、中华鳖的IL 2活性高于当年孵化的草鱼和中华鳖。草鱼、中华鳖脾细胞在 2 5℃培养温度条件下 ,其上清液中IL 2活性最高 ,35℃次之 ,1 5℃最低。因此 ,草鱼、中华鳖IL 2活性在一定范围内是随着年龄增加而增强和依赖温度的。通过小鼠胸腺细胞增殖和对小鼠L92 9细胞杀伤率的实验表明 37℃比 2 5℃检测温度下所测的IL 2活性高 ,而中华鳖胸腺细胞增殖实验却显示 2 5℃检测温度下IL 2活性高于 37℃

Generalized power method for sparse principal component analysis

In this paper we develop a new approach to sparse principal component analysis (sparse PCA). We propose two single-unit and two block optimization formulations of the sparse PCA problem, aimed at extracting a single sparse dominant principal component of a data matrix, or more components at once, respectively. While the initial formulations involve nonconvex functions, and are therefore computationally intractable, we rewrite them into the form of an optimization program involving maximization of a convex function on a compact set. The dimension of the search space is decreased enormously if the data matrix has many more columns (variables) than rows. We then propose and analyze a simple gradient method suited for the task. It appears that our algorithm has best convergence properties in the case when either the objective function or the feasible set are strongly convex, which is the case with our single-unit formulations and can be enforced in the block case. Finally, we demonstrate numerically on a set of random and gene expression test problems that our approach outperforms existing algorithms both in quality of the obtained solution and in computational speed. © 2010 Michel Journée, Yurii Nesterov, Peter Richtárik and Rodolphe Sepulchre.

Optimization on the orthogonal group for independent component analysis

This paper derives a new algorithm that performs independent component analysis (ICA) by optimizing the contrast function of the RADICAL algorithm. The core idea of the proposed optimization method is to combine the global search of a good initial condition with a gradient-descent algorithm. This new ICA algorithm performs faster than the RADICAL algorithm (based on Jacobi rotations) while still preserving, and even enhancing, the strong robustness properties that result from its contrast. © Springer-Verlag Berlin Heidelberg 2007.

Geometric optimization methods for independent component analysis applied on gene expression data

DNA microarrays provide a huge amount of data and require therefore dimensionality reduction methods to extract meaningful biological information. Independent Component Analysis (ICA) was proposed by several authors as an interesting means. Unfortunately, experimental data are usually of poor quality- because of noise, outliers and lack of samples. Robustness to these hurdles will thus be a key feature for an ICA algorithm. This paper identifies a robust contrast function and proposes a new ICA algorithm. © 2007 IEEE.

Molecular characterization and expression profiles in response to bacterial infection of Chinese soft-shelled turtle interleukin-8 (IL-8), the first reptilian chemokine gene

In this study, an IL-8 homologue has been cloned and identified from a reptile, Chinese soft-shelled turtle for the first time. The full-length cDNA of turtle IL-8 was 1188 bp and contained a 312 bp open reading frame (ORF) coding for a protein of 104 amino acids. The chemokine CXC domain, which contained Glu-Leu-Arg (ELR) motif and four cysteine residues, was well conserved in turtle IL-8. The 4924 bp genomic DNA of turtle IL-8 contained four exons and three introns. Phylogenetic analysis showed that the amino acid sequence of turtle IL-8 clustered together with birds. RT-PCR analysis showed that turtle IL-8 mRNA was constitutively expressed liver, spleen, kidney, heart, blood and intestine tissues of control turtles. Real-time quantitative PCR analysis further indicated that the turtle IL-8 mRNA expression was apparent in various tissues at 8 h and up-regulated significantly during 8 h-7 d after Aeromonas hydrophila infection. The present studies will help us to understand the evolution of IL-8 molecule and the inflammatory response mechanism in reptiles. (C) 2009 Elsevier Ltd. All rights reserved.

Component level strategies for exploiting the lifespan of steel in products

Approximately 40% of annual demand for steel worldwide is used to replace products that have failed. With this percentage set to rise, extending the lifespan of steel in products presents a significant opportunity to reduce demand and thus decrease carbon dioxide emissions from steel production. This article presents a new, simplified framework with which to analyse product failure. When applied to the products that dominate steel use, this framework reveals that they are often replaced because a component/sub-assembly becomes degraded, inferior, unsuitable or worthless. In light of this, four products, which are representative of high steel content products in general, are analysed at the component level, determining steel mass and cost profiles over the lifespan of each product. The results show that the majority of the steel components are underexploited - still functioning when the product is discarded; in particular, the potential lifespan of the steel-rich structure is typically much greater than its actual lifespan. Twelve case studies, in which product or component life has been increased, are then presented. The resulting evidence is used to tailor life-extension strategies to each reason for product failure and to identify the economic motivations for implementing these strategies. The results suggest that a product template in which the long-lived structure accounts for a relatively high share of costs while short-lived components can be easily replaced (offering profit to the producer and enhanced utility to owners) encourages product life extension. © 2013 The Author.