75 research outputs found
Antideuteron production in proton-proton and proton-nucleus collisions
The experimental data of the antideuteron production in proton-proton and
proton-nucleus collisions are analyzed within a simple model based on the
diagrammatic approach to the coalescence model. This model is shown to be able
to reproduce most of existing data without any additional parameter.Comment: To appear in Eur. Phys. J A (2002
Parameterization of the antiproton inclusive production cross section on nuclei
A new parameterization of the antiproton inclusive production cross section
in proton-proton and proton-nucleus collisions is proposed. A sample of
consistent pA->pbar X$ experimental data sets measured on 1<A<208 nuclei, from
12 GeV up to 400 GeV incident energy, have been used to constrain the
parameters. A broader energy domain is covered for the pp->pbar X reaction with
a simplified functional form used in the fits. The agreement obtained with the
data is good. The results are discussed.Comment: 10 pages, 11 figures, 7 tables, submitted to Phys. Rev.
A model for A=3 antinuclei production in proton-nucleus collisions
A simple coalescence model based on the same diagrammatic approach of
antimatter production in hadronic collisions as used previously for
antideuterons is used here for the hadroproduction of mass 3 antinuclei. It is
shown that the model is able to reproduce the existing experimental data on
Tbar and 3hebar production without any additional parameter.Comment: 7 figures. submitted to Eur. Phys. J.
Atmospheric and Galactic Production and Propagation of Light Antimatter Nuclei
The production and propagation of light antimatter nuclei has been calculated
using inclusive antiproton production cross sections from a new data analysis,
and coalescence models for the production of composite particles. Particles
were propagated using recently proven phenomenological approaches. The
atmospheric secondary flux is evaluated for the first time. The Galactic flux
obtained are larger than those obtained previously in similar calculations. The
non-annihilating scattering contributions of the propagated particles are
introduced. The preliminary results are shown and discussed.Comment: 4 pages, Contribution to the ICRC 200
General Analysis of Antideuteron Searches for Dark Matter
Low energy cosmic ray antideuterons provide a unique low background channel
for indirect detection of dark matter. We compute the cosmic ray flux of
antideuterons from hadronic annihilations of dark matter for various Standard
Model final states and determine the mass reach of two future experiments
(AMS-02 and GAPS) designed to greatly increase the sensitivity of antideuteron
detection over current bounds. We consider generic models of scalar, fermion,
and massive vector bosons as thermal dark matter, describe their basic features
relevant to direct and indirect detection, and discuss the implications of
direct detection bounds on models of dark matter as a thermal relic. We also
consider specific dark matter candidates and assess their potential for
detection via antideuterons from their hadronic annihilation channels. Since
the dark matter mass reach of the GAPS experiment can be well above 100 GeV, we
find that antideuterons can be a good indirect detection channel for a variety
of thermal relic electroweak scale dark matter candidates, even when the rate
for direct detection is highly suppressed.Comment: 44 pages, 15 Figure
Differential effects of lenalidomide during plasma cell differentiation.
Thalidomide, lenalidomide and pomalidomide have greatly improved the outcome of patients with multiple myeloma. However, their effects on plasma cells, the healthy counterpart of myeloma cells, are unknown. Here, we investigated lenalidomide effects on normal human plasma cell generation using an in vitro model. Lenalidomide inhibited the generation of pre-plasmablasts and early plasma cells, while it moderately affected plasmablast production. It also reduced the expression level of Ikaros, Aiolos, and IRF4 transcription factors, in plasmablasts and early plasma cells. This suggests that their differential sensitivity to lenalidomide is not due to a difference in Ikaros or Aiolos degradation. Lenalidomide also inhibited long-lived plasma cell generation, but did not impair their long-term survival once generated. This last observation is in agreement with the finding that lenalidomide treatment for 3-18 months did not affect the bone marrow healthy plasma cell count in allografted patients with multiple myeloma. Our findings should prompt to investigate whether lenalidomide resistance in patients with multiple myeloma could be associated with the emergence of malignant plasmablasts or long-lived plasma cells that are less sensitive to lenalidomide
ICAM-1-expressing neutrophils exhibit enhanced effector functions in murine models of endotoxemia
This work was supported by funds from the Wellcome Trust (098291/Z/12/Z and 101604/Z/13/Z) (S.N.) and the British Heart Foundation (FS/11/19/28761) (A.W.)
Transcriptomic analysis of milk somatic cells in mastitis resistant and susceptible sheep upon challenge with Staphylococcus epidermidis and Staphylococcus aureus
<p>Abstract</p> <p>Background</p> <p>The existence of a genetic basis for host responses to bacterial intramammary infections has been widely documented, but the underlying mechanisms and the genes are still largely unknown. Previously, two divergent lines of sheep selected for high/low milk somatic cell scores have been shown to be respectively susceptible and resistant to intramammary infections by <it>Staphylococcus spp</it>. Transcriptional profiling with an 15K ovine-specific microarray of the milk somatic cells of susceptible and resistant sheep infected successively by <it>S. epidermidis </it>and <it>S. aureus </it>was performed in order to enhance our understanding of the molecular and cellular events associated with mastitis resistance.</p> <p>Results</p> <p>The bacteriological titre was lower in the resistant than in the susceptible animals in the 48 hours following inoculation, although milk somatic cell concentration was similar. Gene expression was analysed in milk somatic cells, mainly represented by neutrophils, collected 12 hours post-challenge. A high number of differentially expressed genes between the two challenges indicated that more T cells are recruited upon inoculation by <it>S. aureus </it>than <it>S. epidermidis</it>. A total of 52 genes were significantly differentially expressed between the resistant and susceptible animals. Further Gene Ontology analysis indicated that differentially expressed genes were associated with immune and inflammatory responses, leukocyte adhesion, cell migration, and signal transduction. Close biological relationships could be established between most genes using gene network analysis. Furthermore, gene expression suggests that the cell turn-over, as a consequence of apoptosis/granulopoiesis, may be enhanced in the resistant line when compared to the susceptible line.</p> <p>Conclusions</p> <p>Gene profiling in resistant and susceptible lines has provided good candidates for mapping the biological pathways and genes underlying genetically determined resistance and susceptibility towards <it>Staphylococcus </it>infections, and opens new fields for further investigation.</p
The association between human endogenous retroviruses and multiple sclerosis: a systematic review and meta-analysis
Background:
The interaction between genetic and environmental factors is crucial to multiple sclerosis (MS) pathogenesis. Human Endogenous Retroviruses (HERVs) are endogenous viral elements of the human genome whose expression is associated with MS.
Objective:
To perform a systematic review and meta-analysis and to assess qualitative and quantitative evidence on the expression of HERV families in MS patients.
Methods:
Medline, Embase and the Cochrane Library were searched for published studies on the association of HERVs and MS. Meta-analysis was performed on the HERV-W family. Odds Ratio (OR) and 95% confidence interval (CI) were calculated for association.
Results:
43 reports were extracted (25 related to HERV-W, 13 to HERV-H, 9 to HERV-K, 5 to HRES-1 and 1 to HER-15 family). The analysis showed an association between expression of all HERV families and MS. For HERV-W, adequate data was available for meta-analysis. Results from meta-analyses of HERV-W were OR = 22.66 (95%CI 6.32 to 81.20) from 4 studies investigating MSRV/HERV-W(MS-associated retrovirus) envelope mRNA in peripheral blood mononuclear cells, OR = 44.11 (95%CI 12.95 to 150.30) from 6 studies of MSRV/ HERV-W polymerase mRNA in serum/plasma and OR = 6.00 (95%CI 3.35 to 10.74) from 4 studies of MSRV/HERV-W polymerase mRNA in CSF
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