1,510 research outputs found
Quantum generalized Reed-Solomon codes: Unified framework for quantum MDS codes
We construct a new family of quantum MDS codes from classical generalized
Reed-Solomon codes and derive the necessary and sufficient condition under
which these quantum codes exist. We also give code bounds and show how to
construct them analytically. We find that existing quantum MDS codes can be
unified under these codes in the sense that when a quantum MDS code exists,
then a quantum code of this type with the same parameters also exists. Thus as
far as is known at present, they are the most important family of quantum MDS
codes.Comment: 9 pages, no figure
Distances and classification of amino acids for different protein secondary structures
Window profiles of amino acids in protein sequences are taken as a
description of the amino acid environment. The relative entropy or
Kullback-Leibler distance derived from profiles is used as a measure of
dissimilarity for comparison of amino acids and secondary structure
conformations. Distance matrices of amino acid pairs at different conformations
are obtained, which display a non-negligible dependence of amino acid
similarity on conformations. Based on the conformation specific distances
clustering analysis for amino acids is conducted.Comment: 15 pages, 8 figure
A Gemini/GMOS Study of Intermediate Luminosity Early-Type Virgo Cluster Galaxies. I. Globular Cluster and Stellar Kinematics
We present a kinematic analysis of the globular cluster systems and diffuse
stellar light of four intermediate luminosity (sub-) early-type
galaxies in the Virgo cluster based on Gemini/GMOS data. Our galaxy sample is
fainter () than most previous studies, nearly doubling the
number of galaxies in this magnitude range that now have GC kinematics. The
data for the diffuse light extends to , and the data for the globular
clusters reaches 8--. We find that the kinematics in these outer regions
are all different despite the fact that these four galaxies have similar
photometric properties, and are uniformly classified as "fast rotators" from
their stellar kinematics within . The globular cluster systems exhibit a
wide range of kinematic morphology. The rotation axis and amplitude can change
between the inner and outer regions, including a case of counter-rotation. This
difference shows the importance of wide-field kinematic studies, and shows that
stellar and GC kinematics can change significantly as one moves beyond the
inner regions of galaxies. Moreover, the kinematics of the globular cluster
systems can differ from that of the stars, suggesting that the formation of the
two populations are also distinct.Comment: 24 pages, 21 figures, 9 table, ApJ in pres
Molybdenum disulfide quantum dots decorated bismuth sulfide as a superior noble-metal-free photocatalyst for hydrogen evolution through harnessing a broad solar spectrum
The Next Generation Virgo Cluster Survey. X. Properties of Ultra-Compact Dwarfs in the M87, M49 and M60 Regions
We use imaging from the Next Generation Virgo cluster Survey (NGVS) to
present a comparative study of ultra-compact dwarf (UCD) galaxies associated
with three prominent Virgo sub-clusters: those centered on the massive,
red-sequence galaxies M87, M49 and M60. We show how UCDs can be selected with
high completeness using a combination of half-light radius and location in
color-color diagrams ( or ). Although the central galaxies in
each of these sub-clusters have nearly identical luminosities and stellar
masses, we find large differences in the sizes of their UCD populations, with
M87 containing ~3.5 and 7.8 times more UCDs than M49 and M60, respectively. The
relative abundance of UCDs in the three regions scales in proportion to
sub-cluster mass, as traced by X-ray gas mass, total gravitating mass, number
of globular clusters, and number of nearby galaxies. We find that the UCDs are
predominantly blue in color, with ~85% of the UCDs having colors similar to
blue GCs and stellar nuclei of dwarf galaxies. We present evidence that UCDs
surrounding M87 and M49 may follow a morphological sequence ordered by the
prominence of their outer, low surface brightness envelope, ultimately merging
with the sequence of nucleated low-mass galaxies, and that envelope prominence
correlates with distance from either galaxy. Our analysis provides evidence
that tidal stripping of nucleated galaxies is an important process in the
formation of UCDs.Comment: 37 pages, 40 figures. To appear in The Astrophysical Journa
Bandgaps in the propagation and scattering of surface water waves over cylindrical steps
Here we investigate the propagation and scattering of surface water waves by
arrays of bottom-mounted cylindrical steps. Both periodic and random
arrangements of the steps are considered. The wave transmission through the
arrays is computed using the multiple scattering method based upon a recently
derived formulation. For the periodic case, the results are compared to the
band structure calculation. We demonstrate that complete band gaps can be
obtained in such a system. Furthermore, we show that the randomization of the
location of the steps can significantly reduce the transmission of water waves.
Comparison with other systems is also discussed.Comment: 4 pages, 3 figure
Corrigendum: Identification of Hypoxia Induced Metabolism Associated Genes in Pulmonary Hypertension.
[This corrects the article DOI: 10.3389/fphar.2021.753727.]
GWAS and co-expression network combination uncovers multigenes with close linkage effects on the oleic acid content accumulation in Brassica napus
Background: Strong artificial and natural selection causes the formation of highly conserved haplotypes that harbor agronomically important genes. GWAS combination with haplotype analysis has evolved as an effective method to dissect the genetic architecture of complex traits in crop species. Results: We used the 60 K Brassica Infinium SNP array to perform a genome-wide analysis of haplotype blocks associated with oleic acid (C18:1) in rapeseed. Six haplotype regions were identified as significantly associated with oleic acid (C18:1) that mapped to chromosomes A02, A07, A08, C01, C02, and C03. Additionally, whole-genome sequencing of 50 rapeseed accessions revealed three genes (BnmtACP2-A02, BnABCI13-A02 and BnECI1-A02) in the A02 chromosome haplotype region and two genes (BnFAD8-C02 and BnSDP1-C02) in the C02 chromosome haplotype region that were closely linked to oleic acid content phenotypic variation. Moreover, the co-expression network analysis uncovered candidate genes from these two different haplotype regions with potential regulatory interrelationships with oleic acid content accumulation. Conclusions: Our results suggest that several candidate genes are closely linked, which provides us with an opportunity to develop functional haplotype markers for the improvement of the oleic acid content in rapeseed
The properties of bright globular clusters, ultra-compact dwarfs and dwarf nuclei in the Virgo core: hints on origin of ultra-compact dwarf galaxies (UCDs)
Based on the data from the Next Generation Virgo cluster Survey (NGVS), we statistically study the photometric properties of globular clusters (GCs), ultra-compact dwarfs (UCDs) and dwarf nuclei in the Virgo core (M87) region. We found an obvious negative color (g - z) gradient in GC system associate with M87, i.e. GCs in the outer regions are bluer. However, such color gradient does not exist in UCD system, neither in dwarf nuclei system around M87. In addition, we found that many UCDs are surrounded by extended, low surface brightness envelopes. The dwarf nuclei and UCDs show different spatial distributions from GCs, with dwarf nuclei and UCDs (especially for the UCDs with visible envelopes) lying at larger distances to the Virgo center. These results support the view that UCDs (at least for a fraction of UCDs) are more tied to dwarf nuclei than to GCs
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