43 research outputs found
Asymptotic Regge Trajectories of Non-strange Mesons
We analyze the asymptotic behavior of Regge trajectories of non-strange
mesons. In contrast to an existing belief, it is demonstrated that for the
asymptotically linear Regge trajectories the width of heavy hadrons cannot
linearly depend on their mass. Using the data on masses and widths of rho_J,
omega_J, a_J and f_J mesons for the spin values J \leq 6, we extract the
parameters of the asymptotically linear Regge trajectory predicted by the
finite width model of quark gluon bags. As it is shown the obtained parameters
for the data set B correspond to the cross-over temperature lying in the
interval 170.9-175.3 MeV which is consistent with the kinetic freeze-out
temperature of early hadronizing particles found in relativistic heavy ion
collisions at and above the highest SPS energy.Comment: 14 pages, 3 figure
Visualizing variation within Global Pneumococcal Sequence Clusters (GPSCs) and country population snapshots to contextualize pneumococcal isolates
Knowledge of pneumococcal lineages, their geographic distribution and antibiotic resistance patterns, can give insights into
global pneumococcal disease. We provide interactive bioinformatic outputs to explore such topics, aiming to increase dissemination of genomic insights to the wider community, without the need for specialist training. We prepared 12 country-specific
phylogenetic snapshots, and international phylogenetic snapshots of 73 common Global Pneumococcal Sequence Clusters
(GPSCs) previously defined using PopPUNK, and present them in Microreact. Gene presence and absence defined using Roary,
and recombination profiles derived from Gubbins are presented in Phandango for each GPSC. Temporal phylogenetic signal
was assessed for each GPSC using BactDating. We provide examples of how such resources can be used. In our example use of
a country-specific phylogenetic snapshot we determined that serotype 14 was observed in nine unrelated genetic backgrounds
in South Africa. The international phylogenetic snapshot of GPSC9, in which most serotype 14 isolates from South Africa
were observed, highlights that there were three independent sub-clusters represented by South African serotype 14 isolates.
We estimated from the GPSC9-dated tree that the sub-clusters were each established in South Africa during the 1980s. We
show how recombination plots allowed the identification of a 20kb recombination spanning the capsular polysaccharide locus
within GPSC97. This was consistent with a switch from serotype 6A to 19A estimated to have occured in the 1990s from the
GPSC97-dated tree. Plots of gene presence/absence of resistance genes (tet, erm, cat) across the GPSC23 phylogeny were
consistent with acquisition of a composite transposon. We estimated from the GPSC23-dated tree that the acquisition occurred
between 1953 and 1975. Finally, we demonstrate the assignment of GPSC31 to 17 externally generated pneumococcal serotype
1 assemblies from Utah via Pathogenwatch. Most of the Utah isolates clustered within GPSC31 in a USA-specific clade with the
most recent common ancestor estimated between 1958 and 1981. The resources we have provided can be used to explore to
data, test hypothesis and generate new hypotheses. The accessible assignment of GPSCs allows others to contextualize their
own collections beyond the data presented here
Literature Mining for the Discovery of Hidden Connections between Drugs, Genes and Diseases
The scientific literature represents a rich source for retrieval of knowledge on associations between biomedical concepts such as genes, diseases and cellular processes. A commonly used method to establish relationships between biomedical concepts from literature is co-occurrence. Apart from its use in knowledge retrieval, the co-occurrence method is also well-suited to discover new, hidden relationships between biomedical concepts following a simple ABC-principle, in which A and C have no direct relationship, but are connected via shared B-intermediates. In this paper we describe CoPub Discovery, a tool that mines the literature for new relationships between biomedical concepts. Statistical analysis using ROC curves showed that CoPub Discovery performed well over a wide range of settings and keyword thesauri. We subsequently used CoPub Discovery to search for new relationships between genes, drugs, pathways and diseases. Several of the newly found relationships were validated using independent literature sources. In addition, new predicted relationships between compounds and cell proliferation were validated and confirmed experimentally in an in vitro cell proliferation assay. The results show that CoPub Discovery is able to identify novel associations between genes, drugs, pathways and diseases that have a high probability of being biologically valid. This makes CoPub Discovery a useful tool to unravel the mechanisms behind disease, to find novel drug targets, or to find novel applications for existing drugs
QCD and strongly coupled gauge theories : challenges and perspectives
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe
A proposal for testing subcritical vacuum pair production with power lasers
We present a proposal for testing the prediction of non-equilibrium quantum
field theory below the Schwinger limit. The proposed experiments should be able
to detect a measurable number of gamma rays resulting from the annihilation of
pairs in the focal spot of two opposing high intensity laser beams. We discuss
the dependence of the expected number of gamma rays with the laser parameters
and compare with the estimated background level of gamma hits for realistic
laser conditions.Comment: 14 pages, 1 tabl
Employment effects of the provision of specific professional skills and techniques in Germany
Training program, Employment effects, Administrative data, Matching, C 14, C 23, H 43, J 64, J 68,