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Background
The taxonomic name of an organism is a key link between different databases that store information on that organism. However, in the absence of a single, comprehensive database of organism names, individual databases lack an easy means of checking the correctness of a name. Furthermore, the same organism may have more than one name, and the same name may apply to more than one organism. 相似文献22.
SMM?VerstappenEmail author AR?Poole M?Ionescu LE?King M?Abrahamowicz DM?Hofman JWJ?Bijlsma FPJG?Lafeber the Utrecht Rheumatoid Arthritis Cohort Study group 《Arthritis research & therapy》2005,8(1):R31
Introduction
The objective of this study was to determine whether serum biomarkers for degradation and synthesis of the extracellular matrix of cartilage are associated with, and can predict, radiographic damage in patients with rheumatoid arthritis (RA). 相似文献23.
An enzyme family known as adenosine deaminases that act on RNA (ADARs) catalyzes adenosine deamination in RNA. ADARs act on RNA that is largely double-stranded and convert adenosine to inosine, resulting, in many cases, in an I x U pair. Thermodynamic parameters derived from optical melting studies are reported for a series of 14 oligoribonucleotides containing single I x U pairs adjacent to Watson-Crick pairs. In order to determine unique linearly independent nearest neighbor parameters for I x U pairs, four duplexes containing 3'-terminal I x U pairs and four duplexes containing 5'-terminal I x U pairs have also been thermodynamically characterized. This data was combined with previously published data of seven duplexes containing internal, terminal, or tandem I x U pairs from Strobel et al. [Strobel, S. A., Cech, T. R., Usman, N., and Beigelman, L. (1994) Biochemistry 33, 13824-13838] and Serra et al. [Serra, M. J., Smolter, P. E., and Westhof, E. (2004) Nucleic Acids Res. 32, 1824-1828]. On average, a duplex with an internal I x U pair is 2.3 kcal/mol less stable than the same duplex with an A-U pair, however, a duplex with a terminal I x U pair is 0.8 kcal/mol more stable than the same duplex with an A-U pair. Although isosteric with a G-U pair, on average, a duplex with an internal I x U pair is 1.9 kcal/mol less stable than the same duplex with a G-U pair, however, a duplex with a terminal I x U pair is 0.9 kcal/mol more stable than the same duplex with a G-U pair. Duplexes with tandem I x U pairs are on average 5.9 and 3.8 kcal/mol less stable than the same duplex with tandem A-U or tandem G-U pairs, respectively. Using the combined thermodynamic data and a complete linear least-squares fitting routine, nearest neighbor parameters for all nearest neighbor combinations of I x U pairs and an additional parameter for terminal I x U pairs have been derived. 相似文献
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Viktorian Miok Saskia M Wilting Mark A van de Wiel Annelieke Jaspers Paula I van Noort Ruud H Brakenhoff Peter JF Snijders Renske DM Steenbergen Wessel N van Wieringen 《BMC bioinformatics》2014,15(1)
Background
To determine which changes in the host cell genome are crucial for cervical carcinogenesis, a longitudinal in vitro model system of HPV-transformed keratinocytes was profiled in a genome-wide manner. Four cell lines affected with either HPV16 or HPV18 were assayed at 8 sequential time points for gene expression (mRNA) and gene copy number (DNA) using high-resolution microarrays. Available methods for temporal differential expression analysis are not designed for integrative genomic studies.Results
Here, we present a method that allows for the identification of differential gene expression associated with DNA copy number changes over time. The temporal variation in gene expression is described by a generalized linear mixed model employing low-rank thin-plate splines. Model parameters are estimated with an empirical Bayes procedure, which exploits integrated nested Laplace approximation for fast computation. Iteratively, posteriors of hyperparameters and model parameters are estimated. The empirical Bayes procedure shrinks multiple dispersion-related parameters. Shrinkage leads to more stable estimates of the model parameters, better control of false positives and improvement of reproducibility. In addition, to make estimates of the DNA copy number more stable, model parameters are also estimated in a multivariate way using triplets of features, imposing a spatial prior for the copy number effect.Conclusion
With the proposed method for analysis of time-course multilevel molecular data, more profound insight may be gained through the identification of temporal differential expression induced by DNA copy number abnormalities. In particular, in the analysis of an integrative oncogenomics study with a time-course set-up our method finds genes previously reported to be involved in cervical carcinogenesis. Furthermore, the proposed method yields improvements in sensitivity, specificity and reproducibility compared to existing methods. Finally, the proposed method is able to handle count (RNAseq) data from time course experiments as is shown on a real data set.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2105-15-327) contains supplementary material, which is available to authorized users. 相似文献26.
Ribosomal RNA secondary structure: compensatory mutations and implications for phylogenetic analysis 总被引:6,自引:0,他引:6
Using sequence data from the 28S ribosomal RNA (rRNA) genes of selected
vertebrates, we investigated the effects that constraints imposed by
secondary structure have on the phylogenetic analysis of rRNA sequence
data. Our analysis indicates that characters from both base-pairing regions
(stems) and non-base-pairing regions (loops) contain phylogenetic
information, as judged by the level of support of the phylogenetic results
compared with a well-established tree based on both morphological and
molecular data. The best results (the greatest level of support of
well-accepted nodes) were obtained when the complete data set was used.
However, some previously supported nodes were resolved using either the
stem or loop bases alone. Stem bases sustain a greater number of
compensatory mutations than would be expected at random, but the number is
< 40% of that expected under a hypothesis of perfect compensation to
maintain secondary structure. Therefore, we suggest that in phylogenetic
analyses, the weighting of stem characters be reduced by no more than 20%,
relative to that of loop characters. In contrast to previous suggestions,
we do not recommend weighting of stem positions by one-half, compared with
that of loop positions, because this overcompensates for the constraints
that selection imposes on the secondary structure of rRNA.
相似文献
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Clara Correia‐Melo Francisco DM Marques Rhys Anderson Graeme Hewitt Rachael Hewitt John Cole Bernadette M Carroll Satomi Miwa Jodie Birch Alina Merz Michael D Rushton Michelle Charles Diana Jurk Stephen WG Tait Rafal Czapiewski Laura Greaves Glyn Nelson Mohammad Bohlooly‐Y Sergio Rodriguez‐Cuenca Antonio Vidal‐Puig Derek Mann Gabriele Saretzki Giovanni Quarato Douglas R Green Peter D Adams Thomas von Zglinicki Viktor I Korolchuk João F Passos 《The EMBO journal》2016,35(7):724-742
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TT Chowdhury S Arghandawi J Brand OO Akanji DL Bader DM Salter DA Lee 《Arthritis research & therapy》2008,10(2):R35