318 research outputs found
Imperfect Yet Indispensible Financial Integration
Financial integration defines European political economy. Though financial integration was crucial in establishing a common currency for the EU and a relatively shared EU political economy, it was partly responsible for the current EU financial crisis. The major question addressed in this paper is: What lessons can we learn about financial integration from the EU financial crisis? Although the EU crisis has exposed some of the glaring weaknesses of financial integration, it is essential for the EU not to financially and politically disintegrate because of the heavy political-economic interconnectedness and interdependency that constrains member states’ political institutions and economies. Though the EU puts constraints on member states’ political institutions and economies, this is acceptable because it serves the interests of the EU, which in turn provides benefits to its member states
Regge Trajectories for Mesons in the Holographic Dual of Large-N_c QCD
We discuss Regge trajectories of dynamical mesons in large-N_c QCD, using the
supergravity background describing N_c D4-branes compactified on a thermal
circle. The flavor degrees of freedom arise from the addition of N_f<<N_c D6
probe branes. Our work provides a string theoretical derivation, via the
gauge/string correspondence, of a phenomenological model describing the meson
as rotating point-like massive particles connected by a flux string. The
massive endpoints induce nonlinearities for the Regge trajectory. For light
quarks the Regge trajectories of mesons are essentially linear. For massive
quarks our trajectories qualitatively capture the nonlinearity detected in
lattice calculations.Comment: 21 pages, 4 figures. v2: typos corrected, references and
acknowledgments adde
Safety of nifedipine GITS in stable angina: The ACTION trial
Aim: We describe the safety profile of nifedipine GITS as assessed from adverse events reported in the ACTION trial in which 7,665 patients with stable, symptomatic coronary artery disease were randomly assigned nifedipine GITS or placebo and followed for a mean of 4.9 years. Methods: All adverse events were coded using the COSTART coding dictionary. The incidence rate for each event was calculated as the number of patients with the event concerned divided by the total time 'at risk'. Hazard ratios comparing nifedipine with placebo and their 95% confidence intervals were obtained by Cox proportional-hazards analysis. Results: As reported previously, nifedipine significantly reduced the incidence of cardiovascular events and procedures [hazard ratio (HR) 0.89, 95% confidence interval (CI) 0.83-0.95]. Apart from the known side effects of nifedipine, which include peripheral oedema, vasodilatation, hypotension, asthenia, constipation, leg cramps, non-specific respiratory complaints, impotence and polyuria, and which were reported more frequently in patients assigned nifedipine, the incidence rates of most other adverse events were similar. There were no differences in the occurrence of gastrointestinal haemorrhage, myocardial infarction and suicide. The rate of occurrence of death or new cancer excluding non-melanoma skin cancer for patients with no history of cancer at baseline was 2.53/100 patient years for patients assigned nifedipine and 2.37/100 patient years for patients assigned placebo (HR 1.06, 95% CI 0.93-1.22). Conclusion: Overall nifedipine GITS was well tolerated by patients with stable symptomatic angina
Neutrinos in Non-linear Structure Formation - The Effect on Halo Properties
We use N-body simulations to find the effect of neutrino masses on halo
properties, and investigate how the density profiles of both the neutrino and
the dark matter components change as a function of the neutrino mass. We
compare our neutrino density profiles with results from the N-one-body method
and find good agreement. We also show and explain why the Tremaine-Gunn bound
for the neutrinos is not saturated. Finally we study how the halo mass function
changes as a function of the neutrino mass and compare our results with the
Sheth-Tormen semi-analytic formulae. Our results are important for surveys
which aim at probing cosmological parameters using clusters, as well as future
experiments aiming at measuring the cosmic neutrino background directly.Comment: 20 pages, 8 figure
Analysis of chaotic motion and its shape dependence in a generalized piecewise linear map
We analyse the chaotic motion and its shape dependence in a piecewise linear
map using Fujisaka's characteristic function method. The map is a
generalization of the one introduced by R. Artuso. Exact expressions for
diffusion coefficient are obtained giving previously obtained results as
special cases. Fluctuation spectrum relating to probability density function is
obtained in a parametric form. We also give limiting forms of the above
quantities. Dependence of diffusion coefficient and probability density
function on the shape of the map is examined.Comment: 4 pages,4 figure
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Improved estimate of the policy-relevant background ozone in the United States using the GEOS-Chem global model with 1/2° × 2/3° horizontal resolution over North America
The policy-relevant background (PRB) ozone is defined by the US Environmental Protection Agency (EPA) as the surface ozone concentration that would be present over the US in the absence of North American anthropogenic emissions. It is intended to provide a baseline for risk and exposure assessments used in setting the National Ambient Air Quality Standard (NAAQS). We present here three-year statistics (2006–2008) of PRB ozone over the US calculated using the GEOS-Chem global 3-D model of atmospheric composition with 1/2° × 2/3° horizontal resolution over North America and adjacent oceans (2° × 2.5° for the rest of the world). We also provide estimates of the US background (no anthropogenic US emissions) and natural background (no anthropogenic emissions worldwide and pre-industrial methane). Our work improves on previous GEOS-Chem PRB estimates through the use of higher model resolution, 3-year statistics, better representation of stratospheric influence, and updated emissions. PRB is particularly high in the intermountain West due to high elevation, arid terrain, and large-scale subsidence. We present for this region a detailed model evaluation showing that the model is successful in reproducing ozone exceedances up to 70 ppbv. However, the model cannot reproduce PRB-relevant exceptional events associated with wildfires or stratospheric intrusions. The mean PRB estimates for spring–summer are 27 ± 8 ppbv at low-altitude sites and 40 ± 7 ppbv at high-altitude sites. Differences between the PRB simulation and the natural simulation indicate a mean enhancement from intercontinental pollution and anthropogenic methane of 9 ppbv at low-altitude sites and 13 ppbv at high-altitude sites. The PRB is higher than average when ozone exceeds 60 ppbv, particularly in the intermountain West. Our PRB estimates are on average 4 ppbv higher than previous GEOS-Chem studies and we attribute this to higher lighting, increasing Asian emissions, and improved model resolution. Whereas previous studies found no occurrences of PRB exceeding 60 ppbv, we find here some occurrences in the intermountain West. The annual 4th-highest PRB values in the intermountain West are typically 50–60 ppbv, as compared to 35–45 ppbv in the East or on the West Coast. Such high PRB values in the intermountain West suggest that special consideration of this region may be needed if the ozone NAAQS is decreased to a value in the 60–70 ppbv range.Earth and Planetary SciencesEngineering and Applied Science
Localized Backreacted Flavor Branes in Holographic QCD
We investigate the perturbative (in ) backreaction of localized
D8 branes in D4-D8 systems including in particular the Sakai Sugimoto model. We
write down the explicit expressions of the backreacted metric, dilaton and RR
form. We find that the backreaction remains small up to a radial value of , and that the background functions are smooth except
at the D8 sources. In this perturbative window, the original embedding remains
a solution to the equations of motion. Furthermore, the fluctuations around the
original embedding, describing scalar mesons, do not become tachyonic due to
the backreaction in the perturbative regime. This is is due to a cancelation
between the DBI and CS parts of the D8 brane action in the perturbed
background.Comment: 1+48 pages (7 figures) + 15 pages, citations added & minor
correction
Fundamental matter, meson spectroscopy and non-critical string/gauge duality
We discuss the incorporation of quarks in the fundamental representation of
the color group into the non-critical string/gauge duality. We focus on
confining theories and address this question using two different approaches:
(i) by introducing flavor probe branes and (ii) by deriving backreacted
flavored near extremal gravity backgrounds. In the former approach we analyze
the near extremal AdS_6 model with D4 and anti-D4 probe flavor branes included.
We study the meson spectrum and discuss the role played by the constituent
quark mass, related to the integration constant that defines the embedding. As
for the second approach we derive a class of flavored AdS_{n+1} x S^k black
hole solutions. In particular we write down the flavored AdS_6 and AdS_5 black
holes and the near extremal AdS_5 x S^1 backgrounds. We analyze several gauge
dynamical properties associated with these models.Comment: 46 pages, 7 figures. v.2: some references and a comment about the
comparison with analogous critical models were added. v.3: a comment added;
published versio
Holographic technicolor models and their S-parameter
We study the Peskin-Takeuchi S-parameter of holographic technicolor models.
We present the recipe for computing the parameter in a generalized holographic
setup. We then apply it to several holographic models that include: (a) the
Sakai-Sugimoto model and (b) its non-compactified cousin, (c) a non-critical
analog of (a) based on near extremal AdS_6 background, (d) the KMMW model which
is similar to model (a) but with D6 and anti-D6 flavor branes replacing the D8
and anti-D8 branes, (e) a model based on D5 branes compactified on two S^1s
with D7 and anti-7 probe branes and (f) the conifold model with the same probe
branes as in (e). The models are gravity duals of gauge theories with U(N_{TC})
gauge theory and with a breakdown of a flavor symmetry U(N_{TF})xU(N_{TF}) to
U_V(N_{TF}). The models (a), (c),(d) and (e) are duals of a confining gauge
theories whereas (b) and (f) associate with non confining models.
The S-parameter was found to be S=sN_{TC} where s is given by
0.017\lambda_{TC}, 0.016\lambda_{TC}, 0.095, 0.50 and 0.043 for the
(a),(b),(c),(d), (f) models respectively and for model (e) s is divergent.
These results are valid in the large N_{TC} and large \lambda_{TC} limit. We
further derive the dependence of the S-parameter on the "string endpoint" mass
of the techniquarks for the various models. We compute the masses of the low
lying vector technimesons.Comment: 37 pages, 2 figures V2: 2 coerrections in sectionss 4 and 5,
reference adde
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