636 research outputs found
Parton-Hadron-String Dynamics: an off-shell transport approach for relativistic energies
The dynamics of partons, hadrons and strings in relativistic nucleus-nucleus
collisions is analyzed within the novel Parton-Hadron-String Dynamics (PHSD)
transport approach, which is applied to Pb+Pb collisions from 20 to 160 A GeV
in order to explore the space-time regions of 'partonic matter'. We find that
even central collisions at the top-SPS energy of 158 A GeV show a large
fraction of non-partonic, i.e. hadronic or string-like matter, which can be
viewed as a hadronic corona. Furthermore, we observe that the partonic phase
has a very low impact on rapidity distributions of hadrons but a sizeable
influence on the transverse mass distribution of final kaons due to the
repulsive partonic mean fields. We also find a significant effect on the
production of multi-strange antibaryons due to a slightly enhanced
pair production in the partonic phase from massive time-like gluon decay and a
larger formation of antibaryons in the hadronization process. All differential
hadron spectra are analyzed in comparison to the data of experimental
collaborations.Comment: 33 pages, 23 figures, submitted to Nulc. Phys.
Complete genome of a methicillin-resistant Staphylococcus vitulinus from Danish ground beef meat carrying a mecA2 resistance gene and a novel ccr allotype
Objectives: To report the complete genome sequence of a methicillin-resistant Staphylococcus vitulinus
from ground beef to allow comparison with other available S. vitulinus genomes and to investigate its
SCCmec element.
Methods: Meat samples from grocery stores in Denmark were examined for the presence of
staphylococcal species by plating on selective plates. One colony isolated from beef was identified as
S. vitulinus by MALDI-TOF and genome sequenced using a combination of Illumina and Oxford Nanopore
technologies. Phylogenetic and in silico resistome analyses were performed for all available S. vitulinus
genomes.
Results: The closed genome of S. vitulinus Tienloo1 isolate had a chromosome size of 2,628,028 bp and
contained a single novel 2,380 bp plasmid based on a hybrid assembly. It carried mecA as the only
resistance marker. The isolate was found notto carry any immune evasion cluster genes, which have been
putatively associated to human origin. Comparison with all publicly available S. vitulinus draft genomes
showed a diverse population and revealed that only the Danish beef isolate contained a mec gene in
addition to a ccr gene complex. Additionally, the single ccrC gene within the isolate was novel and distant
from the mecA2 gene.
Conclusion: This isolate, Tienloo1, from a ground beef meat sample represents the first complete genome
of S. vitulinus found to carry a mecA2 gene and a novel ccr allotype in its SCCmec element that is distinct
from all publicly available draft S. vitulinus genome
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