1,401 research outputs found
Charmed mesons in nuclear matter
We obtain the properties of charmed mesons in dense matter using a
coupled-channel approach which accounts for Pauli blocking effects and meson
self-energies in a self-consistent manner. We study the behaviour of
dynamically-generated baryonic resonances together with the open-charm meson
spectral functions in this dense nuclear environment. We discuss the
implications of the in-medium properties of open-charm mesons on the
and the predicted X(3700) scalar resonances, and on the
formation of -mesic nuclei.Comment: 5 pages, 5 figures, 1 table, to appear in Proceedings of XIII
International Conference on Hadron Spectroscopy, November 29 - December 4,
2009, Florida State Universit
Implementation of resuspension from paved roads for the improvement of CALIOPE air quality system in Spain
Emissions of resuspensed particles from paved roads (RPR) have received an increasing attention in air quality modeling, since chemistry transport models are generally unable to reproduce particulate levels near road traffic. However, among the models operated in the forecasting mode in Europe, there is a lack of systems including the contribution of RPR on an hourly basis. Therefore, this contribution describes the inclusion of the resuspension of particulate matter within HERMES emission model (operationally implemented in the CALIOPE forecasting system) and the improvements obtained in the simulations of the PM10 mass over a domain covering Spain for a whole year of simulation (2004). The results indicate a remarkable improvement of the PM10 predictions, reducing the biases and errors around 15-18% and 2.6 ÎŒg mâ3 for the average bias in all Spain. The RPR emission have strong local effects on the modeled particle concentration in or near the largest urban zones (up to 7 ÎŒg mâ3 as the annual average), albeit those positive effects are more limited in background areas, since the deposition mechanism was found to be a significant sink for RPR in the chemistry transport model. This approach is accurate and effective in order to improve the prediction of the PM10 mass and becomes essential to achieve the standards set in the regulations for modeling applications
Global and non-global parameters of horizontal branch morphology of globular clusters
The horizontal branch (HB) morphology of globular clusters (GCs) is mainly
determined by metallicity. However, the fact that GCs with almost the same
metallicity exhibit different HB morphologies demonstrates that at least one
more parameter is needed to explain the HB morphology. It has been suggested
that one of these should be a global parameter that varies from GC to GC, and
the other a non-global parameter that varies within the GC. In this study we
provide empirical evidence corroborating this idea. We used the photometric
catalogs obtained with the Advanced Camera for Surveys (ACS) of the Hubble
Space Telescope (HST) and analyse the CMDs of 74 GCs. The HB morphology of our
sample of GCs has been investigated on the basis of the two new parameters L1
and L2 that measure the distance between the RGB and the coolest part of the
HB, and the color extension of the HB, respectively. We find that L1 correlates
with both metallicity and age, whereas L2 most strongly correlates with the
mass of the hosting GC. The range of helium abundance among the stars in a GC,
characterised by Delta Y and associated with the presence of multiple stellar
populations, has been estimated in a few GCs to date. In these GCs we find a
close relationship among Delta Y, GC mass, and L2. We conclude that age and
metallicity are the main global parameters while the range of helium abundance
within a GC is the main non-global parameter defining the HB morphology of
Galactic GCs.Comment: 34 pages, 13 figures, accepted for publication in Ap
The AMBRE Project: searching for the closest solar siblings
Finding solar siblings, that is, stars that formed in the same cluster as the
Sun, will yield information about the conditions at the Sun's birthplace. We
search for solar sibling candidates in AMBRE, the very large spectra database
of solar vicinity stars. Since the ages and chemical abundances of solar
siblings are very similar to those of the Sun, we carried out a chemistry- and
age-based search for solar sibling candidates. We used high-resolution spectra
to derive precise stellar parameters and chemical abundances of the stars. We
used these spectroscopic parameters together with Gaia DR2 astrometric data to
derive stellar isochronal ages. Gaia data were also used to study the
kinematics of the sibling candidates. From the about 17000 stars that are
characterized within the AMBRE project, we first selected 55 stars whose
metallicities are closest to the solar value (-0.1 < [Fe/H] < 0.1 dex). For
these stars we derived precise chemical abundances of several iron-peak, alpha-
and neutron-capture elements, based on which we selected 12 solar sibling
candidates with average abundances and metallicities between -0.03 to 0.03 dex.
Our further selection left us with 4 candidates with stellar ages that are
compatible with the solar age within observational uncertainties. For the 2 of
the hottest candidates, we derived the carbon isotopic ratios, which are
compatible with the solar value. HD186302 is the most precisely characterized
and probably the most probable candidate of our 4 best candidates. Very precise
chemical characterization and age estimation is necessary to identify solar
siblings. We propose that in addition to typical chemical tagging, the study of
isotopic ratios can give further important information about the relation of
sibling candidates with the Sun. Ideally, asteroseismic age determinations of
the candidates could solve the problem of imprecise isochronal ages.Comment: Accepted for publication in A&
Pion Cloud Contribution to K+ Nucleus Scattering
A careful reanalysis is done of the contribution to nucleus
scattering from the interaction of the kaon with the virtual pion cloud. The
usual approximations made in the evaluation of the related kaon selfenergy are
shown to fail badly. We also find new interaction mechanisms which provide
appreciable corrections to the kaon selfenergy. Some of these contribute to the
imaginary part below pion creation threshold. The inclusion of these new
mechanisms in the inelastic part of the optical potential produces a
significant improvement in the differential and total nuclear cross
sections. Uncertainties remain in the dispersive part of the optical potential.Comment: 27 pages, 17 figures (not all of them included, please request them),
report UG-DFM-2/9
Measuring Quality: The Impact of Minimally Invasive Surgery and Operative Time on Surgical Site Infections
Objective: To evaluate the relationship between operative approach, operative time, and SSI rate.Methods: Inpatient database review identified patients undergoing 5 common procedures from 1/2010-12/2011. Patients were stratified into laparoscopic or open approaches. The main outcome measure was the relationship between operative time and SSI by approach.Results: 226,006 patients were evaluated- 28.2% open and 71.8% laparoscopic. Mean overall operative time was significantly shorter laparoscopically (p<0.001). Laparoscopy was associated with significantly lower costs and shorter length of stay (LOS) overall and for each procedure(p<0.0001). Multivariate analysis found SSI increased directly with operative time: for every 30-minute increase, SSI risk increased by 12%. Operative approach was an independent risk factor for SSI: open surgery increased SSI risk by 78%. A direct relationship between open procedures, operative time, and SSI risk was found.Conclusions: Laparoscopy has overall shorter operative time and improved outcomes in SSI rate, LOS, and total costs for common surgical procedures. As operative time and approach were independent risk factors for SSI, the use of laparoscopy and operative time are valuable quality measures
Pionic atoms probing pi-NN resonances
The pion optical potential generated by the hypothetical pi-NN-coupled
NN-decoupled dibaryon resonance d'(2065) is calculated to the lowest order in
nuclear matter density. The contribution to the pion optical potential is found
to be within the empirical errors, so the d'(2065) existence currently does not
contradict to the observed properties of the pi-nucleus bound states. Future
progress in the pionic X-ray spectroscopy can reveal contributions of pi-NN
resonances to energy levels and widths of the pionic atoms.Comment: 3 pages REVTEX, 1 ps figur
Understanding the effect of economic recession on healthcare services: a systematic review
Background: We aimed to examine the available evidence about the impact of the crisis on the use of healthcare services in Europe. Methods: We developed a systematic review of scientific literature for the period 2008-2017. The researchers searched three databases Medline/PubMed, Scopus and Web of Knowledge. For manual searching, several spe-cialized journals of related scope as well as the finalized articles'' reference list were searched. Descriptive and thematic analyses were carried out. PRISMA quality criteria and the recommendations of the Centre for Reviews and Dissemination were followed. Results: Of 3, 685 studies, 35 met inclusion criteria. Regarding âEffects of the social structureâ healthcare accessibility inequalities increased by socioeconomic levels, especially in unemployed, people with low educational levels and migrants. Regarding âHealthcare effectâ, the impact of the recession was observed in unmet needs, pharmaceutical spending containment, reduction of hospital beds, and privatization of services. Conclusion: Austerity policies have contributed to increasing inequalities in the use of health services during the economic downturn. In the current economic climate, new management and health planning strategies such as hospitalisation at home, new models of integrated care and pharmaceutical management are needed to help achieve greater equity and equality in health
Optimisation, by response surface methodology, of degree of hydrolysis and antioxidant and ACE-inhibitory activities of whey protein hydrolysates obtained with cardoon extract
The hydrolysis of bovine whey protein concentrate (WPC), alpha-lactalbumin (alpha-La) and caseinomacropeptide (CMP), by aqueous extracts of Cynara cardunculus, was optimized using response surface methodology. Degree of hydrolysis (DH), angiotensin-converting enzyme (ACE)-inhibitory activity and antioxidant activity were used as objective functions, and hydrolysis time and enzyme/substrate ratio as manipulated parameters. The model was statistically appropriate to describe ACE-inhibitory activity of hydrolysates from WPC and alpha-La, but not from CMP. Maximum DH was 18% and 9%, for WPC and alpha-La, respectively. 50% ACE-inhibition was produced by 105.4 (total fraction) and 25.6 mu g mL(-1) (<3 kDa fraction) for WPC, and 47.6 (total fraction) and 22.5 mu g mL(-1) (<3 kDa fraction) for alpha-La. Major peptides of fractions exhibiting ACE-inhibition were sequenced. The antioxidant activities of WPC and alpha-La were 0.96 +/- 0.08 and 1.12 +/- 0.13 mmol trolox equivalent per mg hydrolysed protein, respectively.info:eu-repo/semantics/acceptedVersio
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