2,670 research outputs found
Reducing Microvascular Dysfunction in Revascularized Patients with ST-Elevation Myocardial Infarction by Off-Target Properties of Ticagrelor versus Prasugrel. Rationale and Design of the REDUCE-MVI Study
Microvascular injury is present in a large proportion of patients with ST-elevation myocardial infarction (STEMI) despite successful revascularization. Ticagrelor potentially mitigates this process by exerting additional adenosine-mediated effects. This study aims to determine whether ticagrelor is associated with a better microvascular function compared to prasugrel as maintenance therapy after STEMI. A total of 110 patients presenting with STEMI and additional intermediate stenosis in another coronary artery will be studied after successful percutaneous coronary intervention (PCI) of the infarct-related artery. Patients will be randomized to treatment with ticagrelor or prasugrel for 1 year. FFR-guided PCI of the non-infarct-related artery will be performed at 1 month. Microvascular function will be assessed by measurement of the index of microcirculatory resistance (IMR) in the infarct-related artery and non-infarct-related artery, immediately after primary PCI and after 1 month. The REDUCE-MVI study will establish whether ticagrelor as a maintenance therapy may improve microvascular function in patients after revascularized STEMI
Energy dependence of multiplicity fluctuations in heavy ion collisions
The energy dependence of multiplicity fluctuations was studied for the most central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV by the NA49 experiment at the CERN SPS. The multiplicity distribution for negatively and positively charged hadrons is significantly narrower than Poisson one for all energies. No significant structure in energy dependence of the scaled variance of multiplicity fluctuations is observed. The measured scaled variance is lower than the one predicted by the grand-canonical formulation of the hadron-resonance gas model. The results for scaled variance are in approximate agreement with the string-hadronic model UrQMD
On the nature of the galactic early-B hypergiants
Despite their importance to a number of astrophysical fields, the lifecycles
of very massive stars are still poorly defined. In order to address this
shortcoming, we present a detailed quantitative study of the physical
properties of four early-B hypergiants (BHGs); Cyg OB2 #12, zeta Sco, HD190603
and BP Cru. These are combined with an analysis of their long-term
spectroscopic and photometric behaviour in order to determine their
evolutionary status. The long-term datasets revealed that they are remarkably
stable over long periods (>40yr), with the possible exception of zeta Sco prior
to the 20th century, in contrast to the typical excursions that characterise
luminous blue variables (LBVs). Zeta Sco, HD190603 and BP Cru possess physical
properties intermediate between B supergiants and LBVs; we therefore suggest
that BHGs are the immediate descendants and progenitors (respectively) of such
stars (for initial masses in the range ~30-60Msun). In contrast, while the wind
properties of Cyg OB2 #12 are consistent with this hypothesis, the combination
of extreme luminosity and spectroscopic mass (~110Msun) and comparatively low
temperature means it cannot be accommodated in such a scheme. Likewise, despite
its co-location with several LBVs above the Humphreys-Davidson (HD) limit, the
lack of long term variability and its unevolved chemistry apparently excludes
such an identification. Since such massive stars are not expected to evolve to
such cool temperatures, the properties of Cyg OB2 #12 are difficult to
understand under current evolutionary paradigms. [ABRIDGED]Comment: 36 pages, 19 figures (of which 17 pages are online supplemental
material). Accepted for publication in Astronomy and Astrophysic
Determinants of vaccination uptake in risk populations: A comprehensive literature review
Vaccination uptake has decreased globally in recent years, with a subsequent rise of vaccine-preventable diseases. Travellers, immunocompromised patients (ICP), and healthcare workers (HCW) are groups at increased risk for (severe) infectious diseases due to their behaviour, health, or occupation, respectively. While targeted vaccination guidelines are available, vaccination uptake seems low. In this review, we give a comprehensive overview of determinants—based on the integrated change model—predicting vaccination uptake in these groups. In travellers, low perceived risk of infection and low awareness of vaccination recommendations contributed to low uptake. Additionally, ICP were often unaware of the recommended vaccinations. A physician’s recommendation is strongly correlated with higher uptake. Furthermore, ICP appeared to be mainly concerned about the risks of vaccination and fear of deterioration of their underlying disease. For HCW, perceived risk of (the severity of) infection for themselves and for their patients together with perceived benefits of vaccination contribute most to their vaccination behaviour. As the determinants that affect uptake are numerous and diverse, we argue that future studies and interventions should be based on multifactorial health behaviour models, especially for travellers and ICP as only a limited number of such studies is available yet
Evaluation of semiautomated internal carotid artery stenosis quantification from 3-dimensional contrast-enhanced magnetic resonance angiograms
Rationale and Objectives: The performance of a semiautomatic technique for internal carotid artery (ICA) stenosis quantification of the internal carotid artery in contrast-enhanced magnetic resonance angiography was evaluated. Materials and Methods: The degree of stenosis of 52 ICAs was quantified by measuring the cross-sectional area along the center lumen line. This was performed both by 3 independent observers and the semiautomated method. The degree of stenosis was defined as the amount of cross-sectional lumen reduction. Results: Agreement between the method and observers was good (weighted-kappa, kappa(w) = 0.89). Reproducibility of measurements of the semiautomated technique was better (kappa(w) = 0.97) than that of the observers (kappa(w) = 0.76), and the evaluated technique was considerably less time-consuming. Conclusions: Because the user interaction is limited, this technique can be used to replace an expert observer in 3-dimensional stenosis quantification of the ICA at CE-MRA in clinical practice
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
Short-term forecasting of off-street parking occupancy
Information and communication technologies have opened the way to guide recent developments in the field of parking. In this paper these technologies are applied to model a decision support system that gives insight into 6-months ahead parking occupancy forecasts for 57 off-street parking locations in Amsterdam. An effect analysis was conducted into the influence of weather-, event-, parking tariff-, and public transport attributes on parking occupancy. The most influential factors on the parking occupancy were the scheduling of artistic and sports events, the addition of a public transport line, and the weather variables thunderstorm, average wind speed, temperature, precipitation, and sunshine duration. Parking tariffs did not significantly contribute to model performance, which could have been because of the lack of data and time variability in the parking tariffs of the examined parking locations. The forecasting algorithms compared were the seasonal naive model as a benchmark approach, the Box–Jenkins seasonal autoregressive integrated moving average with and without exogenous regressors (SARIMAX and SARIMA, respectively), exponential smoothing models, and the long short-term memory neural network. The SARIMAX model outperformed the other algorithms for the 6-months ahead forecasts according to the lowest root mean square error (RMSE). By including the event factor, the model improved by 24% based on the RMSE. Weather variables improved the predictive performance by 8%. Future studies could focus on the addition of more event variables, extension into an online model, and the impact of spatial–temporal features on parking occupancy
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
Short-term forecasting of off-street parking occupancy
Information and communication technologies have opened the way to guide recent developments in the field of parking. In
this paper these technologies are applied to model a decision support system that gives insight into 6-months ahead parking
occupancy forecasts for 57 off-street parking locations in Amsterdam. An effect analysis was conducted into the influence of
weather-, event-, parking tariff-, and public transport attributes on parking occupancy. The most influential factors on the
parking occupancy were the scheduling of artistic and sports events, the addition of a public transport line, and the weather
variables thunderstorm, average wind speed, temperature, precipitation, and sunshine duration. Parking tariffs did not significantly contribute to model performance, which could have been because of the lack of data and time variability in the parking
tariffs of the examined parking locations. The forecasting algorithms compared were the seasonal naive model as a benchmark approach, the Box–Jenkins seasonal autoregressive integrated moving average with and without exogenous regressors
(SARIMAX and SARIMA, respectively), exponential smoothing models, and the long short-term memory neural network.
The SARIMAX model outperformed the other algorithms for the 6-months ahead forecasts according to the lowest root
mean square error (RMSE). By including the event factor, the model improved by 24% based on the RMSE. Weather variables
improved the predictive performance by 8%. Future studies could focus on the addition of more event variables, extension
into an online model, and the impact of spatial–temporal features on parking occupancy
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
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