653 research outputs found
Herwig++ 2.0 Release Note
A new release of the Monte Carlo program Herwig++ (version 2.0) is now
available. This is the first version of the program which can be used for
hadron-hadron physics and includes the full simulation of both initial- and
final-state QCD radiation.Comment: Source code and additional information available at
http://hepforge.cedar.ac.uk/herwig
Herwig++1.0: an event generator for e(+)e(-) annihilation
Results from the new Monte Carlo event generator Herwig++ are presented. This
first version simulates Hadron Emission Reactions With Interfering Gluons in
electron-positron annihilation. The parton shower evolution is carried out
using new evolution variables suited to describing radiation from heavy quarks
as well as light partons. The partonic final state is fragmented into hadrons
by means of an improved cluster hadronization model. The results are compared
with a wide variety of data from LEP and SLC
New developments of the goodness-of-fit Statistical Toolkit
The Statistical Toolkit is a project for the development of open source software tools for statistical data analysis in experimental particle and nuclear physics. The second development cycle encompassed an extension of the software functionality and new tools to facilitate its usage in experimental environments. The new developments include additional goodness-of-fit tests, new implementations of existing tests to improve their statistical precision or computational performance, a new component to extend the usability of the toolkit with other data analysis systems, and new tools for an easier configuration and build of the system in the user's computing environment. The computational performance of all the algorithms implemented has been studied
Medicare for all
OBJECTIVES: Interferon (IFN) alpha is a key immunoregulatory cytokine secreted by activated plasmacytoid dendritic cells (PDC) that constitute less than 1% of leucocytes. IFNalpha plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). Nevertheless, the natural IFNalpha inducers in SLE as well as the different IFNalpha secreting cell types are only partially characterised. METHODS: Chromatin was purified from calf thymus. Human peripheral blood mononuclear cells (PBMC), neutrophils and mouse bone marrow neutrophils were purified and cultured with different stimuli. IFNalpha production was estimated by flow cytometry, ELISA and a bioassay, and gene expression by quantitative real time PCR. Neutrophil activation and NETosis were analysed by flow cytometry, ELISA and confocal microscopy. RESULTS: Neutrophils produced a bioactive IFNalpha on stimulation with purified chromatin. IFNalpha secretion was observed with steady state neutrophils purified from 56 independent healthy individuals and autoimmune patients in response to free chromatin and not chromatin containing immune complexes. Chromatin induced IFNalpha secretion occurred independently of Toll-like receptor 9 (TLR9). Neutrophil priming by granulocyte-colony stimulating factor, granulocyte macrophage-colony stimulating factor or IFNalpha was not necessary but PBMC sustained IFNalpha secretion by neutrophils. PDC were 27 times more efficient than neutrophils but blood neutrophils were 100 times more frequent than PDC. Finally, neutrophil activation by chromatin was associated with NETosis and DNA sensor upregulation. CONCLUSIONS: Neutrophils have the capability of producing IFNalpha on selective triggering, and we identified a natural lupus stimulus involved, unveiling a new mechanism involved in SLE. Neutrophils represent another important source of IFNalpha and important targets for future therapies aimed at influencing IFNalpha levels
Factors Influencing College Students' Perception on Participating in Swimming Activities
The purpose of this research is to determine the variables influencing college students' engagement in swimming activities, as well as the significant themes that often appear in these occurrences. A descriptive research design was used to identify the factors influencing college students' perception of participating in swimming activities. Descriptive research is a type of nonexperimental study that aims to describe the features of phenomena as it occurs. It was found out that participating in swimming activities provides various benefits, some of these include helping build endurance, muscle strength, and cardiovascular fitness, enhanced swimming skills, and maintaining a healthy weight. As a result, the implementation of active recreational activities in schools must be reinforced, not simply for the purpose of participation, but also because students are driven to do so. And these activities must be carried out not just on school grounds, but also at home and in the community
Gel mobility shift scanning of pectin-inducible promoter from Penicillium griseoroseum reveals the involvement of a CCAAT element in the expression of a polygalacturonase gene
Previous reports have described pgg2, a polygalacturonase-encoding gene of Penicillium griseoroseum, as an attractive model for transcriptional regulation studies, due to its high expression throughout several in vitro growth conditions, even in the presence of non-inducing sugars such as sucrose. A search for regulatory motifs in the 5' upstream regulatory sequence of pgg2 identified a putative CCAAT box that could justify this expression profile. This element, located 270 bp upstream of the translational start codon, was tested as binding target for regulatory proteins. Analysis of a 170 bp promoter fragment by electrophoretic mobility shift assay (EMSA) with nuclear extracts prepared from mycelia grown in pectin-containing culture medium revealed a high mobility complex that was subsequently confirmed by analyzing it with a double-stranded oligonucleotide spanning the CCAAT motif. A substitution in the core sequence for GTAGG partially abolished the formation of specific complexes, showing the involvement of the CCAAT box in the regulation of the polygalacturonase gene studied
Offloading electromagnetic shower transport to GPUs
Making general particle transport simulation for high-energy physics (HEP)
single-instruction-multiple-thread (SIMT) friendly, to take advantage of
accelerator hardware, is an important alternative for boosting the throughput
of simulation applications. To date, this challenge is not yet resolved, due to
difficulties in mapping the complexity of Geant4 components and workflow to the
massive parallelism features exposed by graphics processing units (GPU). The
AdePT project is one of the R\&D initiatives tackling this limitation and
exploring GPUs as potential accelerators for offloading some part of the CPU
simulation workload. Our main target is to implement a complete electromagnetic
shower demonstrator working on the GPU. The project is the first to create a
full prototype of a realistic electron, positron, and gamma electromagnetic
shower simulation on GPU, implemented as either a standalone application or as
an extension of the standard Geant4 CPU workflow. Our prototype currently
provides a platform to explore many optimisations and different approaches. We
present the most recent results and initial conclusions of our work, using both
a standalone GPU performance analysis and a first implementation of a hybrid
workflow based on Geant4 on the CPU and AdePT on the GPU.Comment: 8 pages, 4 figures, 20th International Workshop on Advanced Computing
and Analysis Techniques in Physics Research (ACAT 2021), to be published in
Journal of Physics: Conference Series, editor Andrei Gheat
Heavy Flavours in Collider Experiments
Current issues in the studies of Heavy Flavours in colliders are described
with particular emphasis on experiments in which the UK is involved. Results on
charm production at HERA are examined and compared to those at the Tevatron. B
production rates at the Tevatron as well as the status of B lifetimes and
mixing in the LEP collaborations and at the Tevatron are highlighted. The
measurement of sin2beta from CDF is described as well as the most recent
results on top physics at the Tevatron
GeantV: Results from the prototype of concurrent vector particle transport simulation in HEP
Full detector simulation was among the largest CPU consumer in all CERN
experiment software stacks for the first two runs of the Large Hadron Collider
(LHC). In the early 2010's, the projections were that simulation demands would
scale linearly with luminosity increase, compensated only partially by an
increase of computing resources. The extension of fast simulation approaches to
more use cases, covering a larger fraction of the simulation budget, is only
part of the solution due to intrinsic precision limitations. The remainder
corresponds to speeding-up the simulation software by several factors, which is
out of reach using simple optimizations on the current code base. In this
context, the GeantV R&D project was launched, aiming to redesign the legacy
particle transport codes in order to make them benefit from fine-grained
parallelism features such as vectorization, but also from increased code and
data locality. This paper presents extensively the results and achievements of
this R&D, as well as the conclusions and lessons learnt from the beta
prototype.Comment: 34 pages, 26 figures, 24 table
Event shapes in e+e- annihilation and deep inelastic scattering
This article reviews the status of event-shape studies in e+e- annihilation
and DIS. It includes discussions of perturbative calculations, of various
approaches to modelling hadronisation and of comparisons to data.Comment: Invited topical review for J.Phys.G; 40 pages; revised version
corrects some nomenclatur
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