2,718 research outputs found
Particle Multiplicity in Jets and Sub-jets with Jet Axis from Color Current
We study the particle multiplicity in a jet or sub-jet as derived from an
energy-multiplicity 2-particle correlation. This definition avoids the notion
of a globally fixed jet axis and allows for the study of smaller jet cone
openings in a more stable way. The results are sensitive to the mean color
current in the jet from primary parton which takes into
account intermediate partonic processes in the sub-jet production where at high energies. We generalize previous calculations in
Leading Logarithmic Approximation (LLA). The size of the effects related to
this jet axis definition are computed for multiplicities in sub-jets with
different opening angles and energies by including contributions from the
Modified LLA (MLLA) and Next-to-MLLA to the leading order QCD results
Effects of a cocoa diet on an intestinal inflammation model in rats
Cocoa is a rich source of fiber and flavonoids with recognized antioxidant and anti-inflammatory potential. The aim of this study was to evaluate the effects of a cocoa-enriched diet on rats with dextran sulphate sodium (DSS)-induced colitis. Wistar rats were fed with either a 5% cocoa diet or standard diet. Colon inflammation was induced by DSS in the drinking water: 5% for 6 days and 2% over the following 9 days. Colitis was assessed by body weight loss, stool consistency and blood presence in stools. A group of animals fed standard diet was treated with quercitrin (1 mg/kg) after colitis establishment. After 2 weeks of DSS treatment, the colon oxidative and inflammatory status and lymphocyte composition from blood and mesenteric lymph nodes (MLN) were assessed. The cocoa-fed group did not exhibit amelioration of clinical colitis but displayed higher antioxidant activity than the colitic reference group by the restoration of colon glutathione content and prevention of lipid peroxidation. The cocoa diet showed anti-inflammatory potential because it down-regulated serum TNF-alpha, colon iNOS activity and decreased colon cell infiltration. Lymphocyte composition in MLN was not modified by drinking DSS, but there was an increase in the proportion of NK and regulatory T cells in the blood. These changes were not modified by cocoa. In conclusion, cocoa intake may help to inhibit the negative oxidative effects consequent to colitis, although this action is not enough to abrogate the intestinal inflammation significantly
Effect of cocoa-enriched diets on lymphocytes involved in adjuvant arthritis in rats
Cocoa and its flavonoids have potential anti-inflammatory properties in vitro and in acute inflammation models in vivo. The aim of the present study was to ascertain the effects of two cocoa-enriched diets on adjuvant arthritis (AA) in rats, considering not only clinical and biochemical inflammatory indices, but also antibody response and lymphocyte composition. Female Wistar rats were fed with a 5 or 10 % cocoa-enriched diet beginning 2 weeks before arthritis induction and until the end of the study. AA was induced by an intradermal injection of heat-killed Mycobacterium butyricum suspension. The hind-paw swelling (plethysmometry), serum anti-mycobacterial antibody concentration (ELISA), blood and inguinal lymph node lymphocyte subset percentage (flow cytometry), and IL-2, interferon γ and PGE2 released from splenocytes (ELISA) were assessed. Although the cocoa diets had no significant effect on hind-paw swelling, a tendency to reduce it was observed at the end of the study. Cocoa-enriched diets were able to decrease the serum anti-mycobacterial antibody concentration and the splenocyte PGE2 production, as well as the proportion of T-helper (Th) lymphocytes in blood and regional lymph nodes, which probably includes cells responsible for the arthritic process. The cocoa diets prevented a decrease in the proportion of regulatory T-cells in blood and a disequilibrium between inguinal lymph node natural killer (NK) CD8+ and NK CD8− subsets. In conclusion, the cocoa-enriched diets during AA were not able to significantly decrease joint inflammation but modified Th-cell proportions and prevented specific antibody synthesis
Testing M2T/T2M Transformations
Presentado en: 16th International Conference on Model Driven Engineering Languages and Systems (MODELS 2013). Del 29 de septiembre al 4 de octubre. Miami, EEUU.Testing model-to-model (M2M) transformations is becoming a prominent topic in the current Model-driven Engineering landscape. Current approaches for transformation testing, however, assume having explicit model representations for the input domain and for the output domain of the transformation. This excludes other important transformation kinds, such as model-to-text (M2T) and text-to-model (T2M) transformations, from being properly tested since adequate model representations are missing either for the input domain or for the output domain. The contribution of this paper to overcome this gap is extending Tracts, a M2M transformation testing approach, for M2T/T2M transformation testing. The main mechanism we employ for reusing Tracts is to represent text within a generic metamodel. By this, we transform the M2T/T2M transformation specification problems into equivalent M2M transformation specification problems. We demonstrate the applicability of the approach by two examples and present how the approach is implemented for the Eclipse Modeling Framework (EMF). Finally, we apply the approach to evaluate code generation capabilities of several existing UML tools.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto TIN2011-2379
The nuclear and extended infrared emission of the Seyfert galaxy NGC 2992 and the interacting system Arp 245
We present subarcsecond resolution infrared (IR) imaging and mid-IR
spectroscopic observations of the Seyfert 1.9 galaxy NGC 2992, obtained with
the Gemini North Telescope and the Gran Telescopio CANARIAS (GTC). The N-band
image reveals faint extended emission out to ~3 kpc, and the PAH features
detected in the GTC/CanariCam 7.5-13 micron spectrum indicate that the bulk of
this extended emission is dust heated by star formation. We also report
arcsecond resolution MIR and far-IR imaging of the interacting system Arp 245,
taken with the Spitzer Space Telescope and the Herschel Space Observatory.
Using these data, we obtain nuclear fluxes using different methods and find
that we can only recover the nuclear fluxes obtained from the subarcsecond data
at 20-25 micron, where the AGN emission dominates. We fitted the nuclear IR
spectral energy distribution of NGC 2992, including the GTC/CanariCam nuclear
spectrum (~50 pc), with clumpy torus models. We then used the best-fitting
torus model to decompose the Spitzer/IRS 5-30 spectrum (~630 pc) in AGN and
starburst components, using different starburst templates. We find that,
whereas at shorter mid-IR wavelengths the starburst component dominates (64% at
6 micron), the AGN component reaches 90% at 20 micron. We finally obtained dust
masses, temperatures and star formation rates for the different components of
the Arp 245 system and find similar values for NGC 2992 and NGC 2993. These
measurements are within those reported for other interacting systems in the
first stages of the interaction.Comment: 20 pages, 12 figures, accepted by MNRA
Medium-modified evolution of multiparticle production in jets in heavy-ion collisions
The energy evolution of medium-modified average multiplicities and
multiplicity fluctuations in quark and gluon jets produced in heavy-ion
collisions is investigated from a toy QCD-inspired model. In this model, we use
modified splitting functions accounting for medium-enhanced radiation of gluons
by a fast parton which propagates through the quark gluon plasma. The leading
contribution of the standard production of soft hadrons is found to be enhanced
by the factor while next-to-leading order (NLO) corrections are
suppressed by , where the nuclear parameter accounts for
the induced-soft gluons in the hot medium. The role of next-to-next-to-leading
order corrections (NNLO) is studied and the large amount of medium-induced soft
gluons is found to drastically affect the convergence of the perturbative
series. Our results for such global observables are cross-checked and compared
with their limits in the vacuum and a new method for solving the second
multiplicity correlator evolution equations is proposed.Comment: 21 pages and 8 figures, typo corrections, references adde
Next-to-MLLA corrections to single inclusive kt-distributions and 2-particle correlations in a jet
The hadronic kt-spectrum inside a high energy jet is determined including
corrections of relative magnitude O{\sqrt{\alpha_s}} with respect to the
Modified Leading Logarithmic Approximation (MLLA), in the limiting spectrum
approximation (assuming an infrared cut-off Q0 =Lambda_{QCD}) and beyond
Q_0\ne\Lambda_{QCD}. The results in the limiting spectrum approximation are
found to be, after normalization, in impressive agreement with preliminary
measurements by the CDF collaboration, unlike what occurs at MLLA, pointing out
small overall non-perturbative contributions. Within the same framework,
2-particle correlations inside a jet are also predicted at NMLLA and compared
to previous MLLA calculations.Comment: 35 pages and 39 figures. Comments, appendices, figures, references
added. Version to appear in Phys. Rev.
The starburst-AGN connection in the merger galaxy Mrk 938: an infrared and X-ray view
Mrk938 is a luminous infrared galaxy in the local Universe believed to be the
remnant of a galaxy merger. It shows a Seyfert 2 nucleus and intense star
formation according to optical spectroscopic observations. We have studied this
galaxy using new Herschel far-IR imaging data in addition to archival X-ray,
UV, optical, near-IR and mid-IR data. Mid- and far-IR data are crucial to
characterise the starburst contribution, allowing us to shed new light on its
nature and to study the coexistence of AGN and starburst activity in the local
Universe. The decomposition of the mid-IR Spitzer spectrum shows that the AGN
bolometric contribution to the mid-IR and total infrared luminosity is small
(Lbol(AGN)/LIR~0.02), which agrees with previous estimations. We have
characterised the physical nature of its strong infrared emission and
constrained it to a relatively compact emitting region of <2kpc. It is in this
obscured region where most of the current star formation activity is taking
place as expected for LIRGs. We have used Herschel imaging data for the first
time to constrain the cold dust emission with unprecedented accuracy. We have
fitted the integrated far-IR spectral energy distribution and derived the
properties of the dust, obtaining a dust mass of 3x10^7Msun. The far-IR is
dominated by emission at 35K, consistent with dust heated by the on-going star
formation activity.Comment: 12 pages, 6 figures, 4 tables, accepted for publication in MNRA
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