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1.
This study confirms that the two known Chlorociboria species from North America correspond to Chlorociboria aeruginascens and Chlorociboria aeruginosa that were originally described from Europe. The anamorphs of these two species are unambiguously identified for the first time: the genetic connection between C. aeruginascens is Dothiorina tulasnei, is here demonstrated for the first time by molecular data, and the anamorph of C. aeruginosa was previously undescribed. These two species are more closely related to different Southern Hemisphere taxa than they are to each other, indicating complex speciation processes in a global geographic context. Pure cultures isolated from the two species were grown on various media for examination of growth rate, sporulation, and xylindein production. The latter is responsible for green staining of wood and has applications in craftsmanship and perhaps also for drug development.  相似文献   

2.
农业生态系统能量分析   总被引:33,自引:2,他引:33  
农业生态系统的能量分析从能流着手进行农业生态系统的功能量化分析,是农业生态系统重要的研究方法之一。本文简要回顾讨论了农业生态系统能量分析研究的历史和进展。着重讨论了能值分析方法对传统能量分析方法的新发展,分析了农业生态系统能量分析目前存在的问题,并就其进一步发展方向进行了探讨能值分析方法用生产某种能量或物质所直接或间接耗用的太阳能值量来衡量该能量或物质的价值,不仅在概念上而且在算法上都是原有能量分析方法的新发展.发展到能值分析阶段的农业生态系统的能量分析方法亦存有自身的不足之处,如能值转换率的计算过于繁复,能值指标体系缺乏统一性及系统可持续发展的能值综合评价指标缺乏等。这些问题的解决与能值最大功率的明晰化、能值分析与能量及耗散分析的结合、与物质分析及景观结构分析的结合等研究等共同构成了农业生态系统能量分析的几大发展方向。  相似文献   

3.
海量数据时代考察文本分析技术在生物信息学领域的应用具有重要的理论和现实价值。本文讨论了文本分析在蛋白质计算分析中的几个应用实例以及核心技术内容。文本分析技术应用于生物信息学领域可发挥引领和导向作用,在生物信息学中的应用又进一步促进了文本分析技术的发展。文本分析技术虽然广泛在生物信息学中应用,但是其发展仍然有需要尚待解决的几个问题,本文对此也进行了讨论。  相似文献   

4.
CorrXpression is a stand-alone desktop application for the identification of significant genes within collections of microarrays. The software combines three methods in two steps of analysis: correspondence analysis (CA), ratio analysis and correlation analysis. The graphical interface of CorrXpression visualizes the result of the CA with a biplot and the expression of selected genes in dependency of the experiments as bar diagrams. The CA-plot is an excellent tool for visualization and evaluation of data and results of ratio analysis and correlation analysis. The input data are selected from a database or from appropriate ASCII files.  相似文献   

5.
Matrix rank analysis, a method extensively used to enumerate interacting species or components in various biological systems, has been compared with the more readily available technique of factor analysis. Data previously analyzed by matrix rank analysis has been subjected to factor analysis. The results show that there are some agreements and disagreements between the two methods. The sources and nature of the disagreements are discussed. Our work indicates that factor analysis may be preferable to matrix rank analysis.  相似文献   

6.
Genomic Diversity of Field Isolates of Burkholderia solanacearum in Japan   总被引:1,自引:0,他引:1  
Genomic differences between 18 isolates of Burkholderia solanacearum originated from diseased plants cultivated in nine different agricultural fields were examined by using four DNA-based methods: repetitive DNA polymorphism analysis, restriction-site analysis of polymerase chain reaction products, random amplified polymorphic DNA (RAPD) analysis, and macrorestriction analysis. Genomic diversity among the isolates was detected by RAPD and macrorestriction analysis. The latter revealed the regional variation of the genome structure among the isolates, suggesting that B. solanacearum populations consist of a number of independent clonal lines.  相似文献   

7.
新基因功能研究的策略与方法   总被引:1,自引:0,他引:1  
开展新基因功能研究在当前生物医学研究中变得日益重要.基因功能的研究策略主要包括新基因的生物信息学及体内表达规律分析、功能获得与功能失活策略研究、基因编码产物相互作用蛋白的研究.同时,结合近年来国内外的一些新进展,对与各种策略相关的一些技术方法也进行了介绍.  相似文献   

8.
In-depth analysis of the serum and plasma proteomes by mass spectrometry is challenged by the vast dynamic range of protein abundance and substantial complexity. There is merit in reducing complexity through fractionation to facilitate mass spectrometry analysis of low-abundance proteins. However, fractionation reduces throughput and has the potential of diluting individual proteins or inducing their loss. Here, we have investigated the contribution of extensive fractionation of intact proteins to depth of analysis. Pooled serum depleted of abundant proteins was fractionated by an orthogonal two-dimensional system consisting of anion-exchange and reversed-phase chromatography. The resulting protein fractions were aliquotted; one aliquot was analyzed by shotgun LC-MS/MS, and another was further resolved into protein bands in a third dimension using SDS-PAGE. Individual gel bands were excised and subjected to in situ digestion and mass spectrometry. We demonstrate that increased fractionation results in increased depth of analysis based on total number of proteins identified in serum and based on representation in individual fractions of specific proteins identified in gel bands following a third-dimension SDS gel analysis. An intact protein analysis system (IPAS) based on a two-dimensional plasma fractionation schema was implemented that resulted in identification of 1662 proteins with high confidence with representation of protein isoforms that differed in their chromatographic mobility. Further increase in depth of analysis was accomplished by repeat analysis of aliquots from the same set of two-dimensional fractions resulting in overall identification of 2254 proteins. We conclude that substantial depth of analysis of proteins from milliliter quantities of serum or plasma and detection of isoforms are achieved with depletion of abundant proteins followed by two-dimensional protein fractionation and MS analysis of individual fractions.  相似文献   

9.
By aggregating data for complex traits in a biologically meaningful way, gene and gene-set analysis constitute a valuable addition to single-marker analysis. However, although various methods for gene and gene-set analysis currently exist, they generally suffer from a number of issues. Statistical power for most methods is strongly affected by linkage disequilibrium between markers, multi-marker associations are often hard to detect, and the reliance on permutation to compute p-values tends to make the analysis computationally very expensive. To address these issues we have developed MAGMA, a novel tool for gene and gene-set analysis. The gene analysis is based on a multiple regression model, to provide better statistical performance. The gene-set analysis is built as a separate layer around the gene analysis for additional flexibility. This gene-set analysis also uses a regression structure to allow generalization to analysis of continuous properties of genes and simultaneous analysis of multiple gene sets and other gene properties. Simulations and an analysis of Crohn’s Disease data are used to evaluate the performance of MAGMA and to compare it to a number of other gene and gene-set analysis tools. The results show that MAGMA has significantly more power than other tools for both the gene and the gene-set analysis, identifying more genes and gene sets associated with Crohn’s Disease while maintaining a correct type 1 error rate. Moreover, the MAGMA analysis of the Crohn’s Disease data was found to be considerably faster as well.  相似文献   

10.
目的:采用常用的电子表格处理系统Microsoft Excel解决药学实验过程中遇到的数据分析问题。方法:应用工作表函数中内置的统计函数,以线性回归为例说明源数据的输入与结果返回的具体操作过程;对数据分析工具中的"描述统计"工具、t检验与方差分析,结合具体实例对药学实践中遇到的药学统计实际问题进行综合探讨。结果:用Excel表中内置的统计函数工具进行线性回归分析,方法简单、结果可靠;Excel表中的数据分析工具适用于日常药学实验数据分析过程中遇到的描述统计分析、t检验与方差分析。Excel与其它数据处理软件相比具有操作快捷、使用方便、计算精确、易于学习与掌握等优点。结论:Excel友好的界面,清晰的统计分析结果,使医药工作者在使用Excel的数据分析软件时会感到非常的方便快捷,灵活实用,值得在药学实践中应用推广。  相似文献   

11.
群落二维格局分析的两种方法   总被引:4,自引:0,他引:4  
张金屯 《西北植物学报》2004,24(8):1448-1451
群落二维空间格局研究能够更好地揭示群落的特征,但在分析方法上有较大的困难。用垂直相交的两条样带在两个方向上同时取样的二维取样法,获得数据,用DCA排序与格局分析相结合的方法,得到群落不同格局规模斑块的长、宽及面积,实现二维格局研究。在亚高山草甸群落格局研究中应用表明,两个方法均是有效的。  相似文献   

12.
目的:谱分析是信号处理的常用方法,其中的统计相关分析、傅里叶变换、小波变换和数字滤波等手段已逐渐应用到DNA序列的分析中,这些应用包括DNA序列的周期性分析、基因识别和同源性分析等方面。本文对谱分析方法在DNA序列分析中的应用情况进行简单的综述。  相似文献   

13.
The development of multiple DNA methylation analysis techniques, including higher-throughput assays, has resulted in data structures of increasing complexity and diversity. Here, we discuss the general principles of DNA methylation analysis and propose a nomenclature for the various types of methylation analysis. We briefly outline several DNA methylation analysis techniques and discuss how these different technologies affect the structure of the resulting methylation data. We then describe the basic statistics and bioinformatic principles relevant to the analysis of simple and complex methylation data.  相似文献   

14.
15.
Fundamentals of cDNA microarray data analysis   总被引:15,自引:0,他引:15  
Microarray technology is a powerful approach for genomics research. The multi-step, data-intensive nature of this technology has created an unprecedented informatics and analytical challenge. It is important to understand the crucial steps that can affect the outcome of the analysis. In this review, we provide an overview of the contemporary trend on various main analysis steps in the microarray data analysis process, which includes experimental design, data standardization, image acquisition and analysis, normalization, statistical significance inference, exploratory data analysis, class prediction and pathway analysis, as well as various considerations relevant to their implementation.  相似文献   

16.
17.
微生物生态研究中基于BIOLOG方法的数据分析   总被引:21,自引:0,他引:21  
BIOLOG微平板法作为一种方便快速的微生物检验技术,已广泛应用于环境微生物检测,微生物生态研究等方面,发挥着越来越重要的作用。该方法可以获得关于微生物群落碳源利用能力的大量数据,反映出关于微生物活性的丰富信息。然而大量的数据也对解释和分析提出了挑战,分析了应用于BIOLOG产生数据的统计分析方法,对常用的AWCD值计算,多样性指数计算,主成分分析(PCA),聚类分析,相关、回归等方法深入探讨,阐述各自的功能、不足以及在应用中容易出现的问题。另外也对一些不常见的方法,如非参数多元分析(Non-Parametric version of MANOVA/Permutation version of MANOVA)、动力学参数分析、多元回归树、典范对应分析等也进行了讨论。通过对不同方法应用目标和原理的分析论述了各自优缺点,对微生物研究中基于BIOLOG方法数据分析的选择应用提供参考。  相似文献   

18.
目的 探讨失效模式与效应分析在皮肤科肿物切除术门诊手术流程管理中的应用效果。方法 成立失效模式与效应分析工作小组,利用失效模式与效应分析(FMEA),对皮肤科肿物切除门诊手术流程管理的问题进行失效模式的分析、评估与改进。结果 准确分析出皮肤科肿物切除术门诊手术流程管理中存在的术后照护模式不当、排队等候时间过长及门诊挂号流程复杂等问题,并针对失效模式与效应分析的问题提出要加强术后复诊流程标示、完善门诊挂号方式及流程等建议。结论FMEA可以很好地应用于皮肤科肿物切除术门诊手术流程的管理中,确保门诊手术流程的规范和医疗服务质量。  相似文献   

19.
以上海市医疗质量安全监控系统为切入点,系统介绍故障模式效应及危害性分析的程序选择、专家组建、资料准备、危害性分析、根源性分析、措施提出和改善评估等7个步骤在监控系统的应用,以探讨上海市医疗质量安全监控系统分析子系统的定性分析模式。  相似文献   

20.
The analysis of polychoric correlations via principal component analysis and exploratory factor analysis are well-known approaches to determine the dimensionality of ordered categorical items. However, the application of these approaches has been considered as critical due to the possible indefiniteness of the polychoric correlation matrix. A possible solution to this problem is the application of smoothing algorithms. This study compared the effects of three smoothing algorithms, based on the Frobenius norm, the adaption of the eigenvalues and eigenvectors, and on minimum-trace factor analysis, on the accuracy of various variations of parallel analysis by the means of a simulation study. We simulated different datasets which varied with respect to the size of the respondent sample, the size of the item set, the underlying factor model, the skewness of the response distributions and the number of response categories in each item. We found that a parallel analysis and principal component analysis of smoothed polychoric and Pearson correlations led to the most accurate results in detecting the number of major factors in simulated datasets when compared to the other methods we investigated. Of the methods used for smoothing polychoric correlation matrices, we recommend the algorithm based on minimum trace factor analysis.  相似文献   

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