A preliminary calculation for the low-lying branches of phonon dispersion relations of α-LiIO3 in directions [001], [100] and [110] using a simplified model are reported. In addition, we point out that coupling betwe...A preliminary calculation for the low-lying branches of phonon dispersion relations of α-LiIO3 in directions [001], [100] and [110] using a simplified model are reported. In addition, we point out that coupling between different vibration modes may be important in lattice dynamics of such crystals.展开更多
Phylogenetic tree of coronaviruses (CoVs) in-cluding the human SARS-associated virus is reconstructed from complete genomes by using our newly developed K- string composition approach. The relation of the human SARS-C...Phylogenetic tree of coronaviruses (CoVs) in-cluding the human SARS-associated virus is reconstructed from complete genomes by using our newly developed K- string composition approach. The relation of the human SARS-CoV to other coronaviruses, i.e. the rooting of the tree is suggested by choosing an appropriate outgroup. SARS-CoV makes a separate group closer but still distant from G2 (CoVs in mammalian host). The relation between different isolates of the human SARS virus is inferred by first constructing an ultrametric distance matrix from counting sequence variations in the genomes. The resulting tree is consistent with clinic relations between the SARS-CoV isolates. In addition to a larger variety of coronavirus ge-nomes these results provide phylogenetic knowledge based on independent novel methodology as compared to recent phylogenetic studies on SARS-CoV.展开更多
The newly proposed alignment-free and parameter-free composition vector (CVtree) method has been successfully applied to infer phylogenetic relationship of viruses, chloroplasts, bacteria, and fungi from their whole-g...The newly proposed alignment-free and parameter-free composition vector (CVtree) method has been successfully applied to infer phylogenetic relationship of viruses, chloroplasts, bacteria, and fungi from their whole-genome data. In this study we pay special attention to the phylogenetic positions of 56 Archaea genomes among which 7 species have not been listed either in Bergey’s Manual of Systematic Bacteriology or in Taxonomic Outline of Bacteria and Archaea (TOBA). By inspecting the stable monophyletic branchings in CVTrees reconstructed from a total of 861 genomes (56 Archaea plus 797 Bacteria, using 8 Eukarya as outgroups) definite taxonomic assignments were proposed for these not-fully-classified species. Further development of Archaea taxonomy may verify the predicted phylogenetic results of the CVTree approach.展开更多
We perform an exhaustive, taxon by taxon, comparison of the branchings in the composition vector trees (CVTrees) inferred from 432 prokaryotic genomes available on 31 December 2006, with the bacte-riologists' taxo...We perform an exhaustive, taxon by taxon, comparison of the branchings in the composition vector trees (CVTrees) inferred from 432 prokaryotic genomes available on 31 December 2006, with the bacte-riologists' taxonomy-primarily the latest online Outline of the Bergey's Manual of Systematic Bacteri-ology. The CVTree phylogeny agrees very well with the Bergey's taxonomy in majority of fine branchings and overall structures. At the same time most of the differences between the trees and the Manual have been known to biologists to some extent and may hint at taxonomic revisions. Instead of demonstrating the overwhelming agreement this paper puts emphasis on the biological implications of the differences.展开更多
In order to show that the newly developed K-string composition distance method, based on counting oligopeptide frequencies, for inferring phylogenetic relations of prokaryotes works equally well without requiring the ...In order to show that the newly developed K-string composition distance method, based on counting oligopeptide frequencies, for inferring phylogenetic relations of prokaryotes works equally well without requiring the whole proteome data, we used all ribosomal proteins and the set of aminoacyl tRNA synthetases for each species. The latter group has been known to yield inconsistent trees if used individually. Our trees are obtained without making any sequence alignment. Altogether 16 Archaea, 105 Bacteria and 2 Eucarya are represented on the tree. Most of the lower branchings agree well with the latest, 2003, Outline of the second edition of the Bergeys Manual of Systematic Bacteriology and the trees also suggest some relationships among higher taxa.展开更多
文摘A preliminary calculation for the low-lying branches of phonon dispersion relations of α-LiIO3 in directions [001], [100] and [110] using a simplified model are reported. In addition, we point out that coupling between different vibration modes may be important in lattice dynamics of such crystals.
文摘Phylogenetic tree of coronaviruses (CoVs) in-cluding the human SARS-associated virus is reconstructed from complete genomes by using our newly developed K- string composition approach. The relation of the human SARS-CoV to other coronaviruses, i.e. the rooting of the tree is suggested by choosing an appropriate outgroup. SARS-CoV makes a separate group closer but still distant from G2 (CoVs in mammalian host). The relation between different isolates of the human SARS virus is inferred by first constructing an ultrametric distance matrix from counting sequence variations in the genomes. The resulting tree is consistent with clinic relations between the SARS-CoV isolates. In addition to a larger variety of coronavirus ge-nomes these results provide phylogenetic knowledge based on independent novel methodology as compared to recent phylogenetic studies on SARS-CoV.
基金supported by the National Basic Research Program of China (2007CB814800)Shanghai Leading Academic Discipline Project (B111)
文摘The newly proposed alignment-free and parameter-free composition vector (CVtree) method has been successfully applied to infer phylogenetic relationship of viruses, chloroplasts, bacteria, and fungi from their whole-genome data. In this study we pay special attention to the phylogenetic positions of 56 Archaea genomes among which 7 species have not been listed either in Bergey’s Manual of Systematic Bacteriology or in Taxonomic Outline of Bacteria and Archaea (TOBA). By inspecting the stable monophyletic branchings in CVTrees reconstructed from a total of 861 genomes (56 Archaea plus 797 Bacteria, using 8 Eukarya as outgroups) definite taxonomic assignments were proposed for these not-fully-classified species. Further development of Archaea taxonomy may verify the predicted phylogenetic results of the CVTree approach.
文摘We perform an exhaustive, taxon by taxon, comparison of the branchings in the composition vector trees (CVTrees) inferred from 432 prokaryotic genomes available on 31 December 2006, with the bacte-riologists' taxonomy-primarily the latest online Outline of the Bergey's Manual of Systematic Bacteri-ology. The CVTree phylogeny agrees very well with the Bergey's taxonomy in majority of fine branchings and overall structures. At the same time most of the differences between the trees and the Manual have been known to biologists to some extent and may hint at taxonomic revisions. Instead of demonstrating the overwhelming agreement this paper puts emphasis on the biological implications of the differences.
基金This work was partly supported by the Special Funds for Major State Basic Research Projects(Grant No.G2000077308)National Natural Science Foundation of China(Grant No.30170232)+1 种基金the Innovation Project of Chinese Academy of Sciencesby a grant from Shaghai Municipality via Fudan University.
文摘In order to show that the newly developed K-string composition distance method, based on counting oligopeptide frequencies, for inferring phylogenetic relations of prokaryotes works equally well without requiring the whole proteome data, we used all ribosomal proteins and the set of aminoacyl tRNA synthetases for each species. The latter group has been known to yield inconsistent trees if used individually. Our trees are obtained without making any sequence alignment. Altogether 16 Archaea, 105 Bacteria and 2 Eucarya are represented on the tree. Most of the lower branchings agree well with the latest, 2003, Outline of the second edition of the Bergeys Manual of Systematic Bacteriology and the trees also suggest some relationships among higher taxa.