443 research outputs found
Does Banque de France control inflation and unemployment?
We re-estimate statistical properties and predictive power of a set of
Phillips curves, which are expressed as linear and lagged relationships between
the rates of inflation, unemployment, and change in labour force. For France,
several relationships were estimated eight years ago. The change rate of labour
force was used as a driving force of inflation and unemployment within the
Phillips curve framework. The set of nested models starts with a simplistic
version without autoregressive terms and one lagged term of explanatory
variable. The lag is determined empirically together with all coefficients. The
model is estimated using the Boundary Element Method (BEM) with the least
squares method applied to the integral solutions of the differential equations.
All models include one structural break might be associated with revisions to
definitions and measurement procedures in the 1980s and 1990s as well as with
the change in monetary policy in 1994-1995. For the GDP deflator, our original
model provided a root mean squared forecast error (RMSFE) of 1.0% per year at a
four-year horizon for the period between 1971 and 2004. The rate of CPI
inflation is predicted with RMSFE=1.5% per year. For the naive (no change)
forecast, RMSFE at the same time horizon is 2.95% and 3.3% per year,
respectively. Our model outperforms the naive one by a factor of 2 to 3. The
relationships for inflation were successfully tested for cointegration. We have
formally estimated several vector error correction (VEC) models for two
measures of inflation. At a four year horizon, the estimated VECMs provide
significant statistical improvements on the results obtained by the BEM:
RMSFE=0.8% per year for the GDP deflator and ~1.2% per year for CPI. For a two
year horizon, the VECMs improve RMSFEs by a factor of 2, with the smallest
RMSFE=0.5% per year for the GDP deflator.Comment: 25 pages, 12 figure
Inflation, Unemployment, and Labour Force: Phillips Curves and Long-Term Projections for Austria
Inflation, Unemployment, and Labor Force: Phillips Curves and Long-Term Projections for Japan
Thoracolumbar injury classification and severity score: a new paradigm for the treatment of thoracolumbar spine trauma
BACKGROUND: Contemporary understanding of the biomechanics, natural history, and methods of treating thoracolumbar spine injuries continues to evolve. Current classification schemes of these injuries, however, can be either too simplified or overly complex for clinical use.
METHODS: The Spine Trauma Group was given a survey to identify similarities in treatment algorithms for common thoracolumbar injuries, as well as to identify characteristics of injury that played a key role in the decision-making process.
RESULTS: Based on the survey, the Spine Trauma Group has developed a classification system and an injury severity score (thoracolumbar injury classification and severity score, or TLICS), which may facilitate communication between physicians and serve as a guideline for treating these injuries. The classification system is based on the morphology of the injury, integrity of the posterior ligamentous complex, and neurological status of the patient. Points are assigned for each category, and the final total points suggest a possible treatment option.
CONCLUSIONS: The usefulness of this new system will have to be proven in future studies investigating inter- and intraobserver reliability, as well as long-term outcome studies for operative and nonoperative treatment methods
Measurements of Dihadron Correlations Relative to the Event Plane in Au+Au Collisions at GeV
Dihadron azimuthal correlations containing a high transverse momentum (\pt)
trigger particle are sensitive to the properties of the nuclear medium created
at RHIC through the strong interactions occurring between the traversing parton
and the medium, i.e. jet-quenching. Previous measurements revealed a strong
modification to dihadron azimuthal correlations in Au+Au collisions with
respect to \pp\ and \dAu\ collisions. The modification increases with the
collision centrality, suggesting a path-length dependence to the jet-quenching
effect. This paper reports STAR measurements of dihadron azimuthal correlations
in mid-central (20-60\%) Au+Au collisions at \snn=200~GeV as a function of
the trigger particle's azimuthal angle relative to the event plane,
\phis=|\phit-\psiEP|. The azimuthal correlation is studied as a function of
both the trigger and associated particle \pt. The subtractions of the
combinatorial background and anisotropic flow, assuming Zero Yield At Minimum
(\zyam), are described. The away-side correlation is strongly modified, and the
modification varies with \phis, which is expected to be related to the
path-length that the away-side parton traverses. The pseudo-rapidity (\deta)
dependence of the near-side correlation, sensitive to long range \deta
correlations (the ridge), is also investigated. The ridge and jet-like
components of the near-side correlation are studied as a function of \phis.
The ridge appears to drop with increasing \phis while the jet-like component
remains approximately constant. ...Comment: 50 pages, 39 figures, 6 table
Studies of di-jet survival and surface emission bias in Au+Au collisions via angular correlations with respect to back-to-back leading hadrons
We report first results from an analysis based on a new multi-hadron
correlation technique, exploring jet-medium interactions and di-jet surface
emission bias at RHIC. Pairs of back-to-back high transverse momentum hadrons
are used for triggers to study associated hadron distributions. In contrast
with two- and three-particle correlations with a single trigger with similar
kinematic selections, the associated hadron distribution of both trigger sides
reveals no modification in either relative pseudo-rapidity or relative
azimuthal angle from d+Au to central Au+Au collisions. We determine associated
hadron yields and spectra as well as production rates for such correlated
back-to-back triggers to gain additional insights on medium properties.Comment: By the STAR Collaboration. 6 pages, 2 figure
Observation of the antimatter helium-4 nucleus
High-energy nuclear collisions create an energy density similar to that of
the universe microseconds after the Big Bang, and in both cases, matter and
antimatter are formed with comparable abundance. However, the relatively
short-lived expansion in nuclear collisions allows antimatter to decouple
quickly from matter, and avoid annihilation. Thus, a high energy accelerator of
heavy nuclei is an efficient means of producing and studying antimatter. The
antimatter helium-4 nucleus (), also known as the anti-{\alpha}
(), consists of two antiprotons and two antineutrons (baryon
number B=-4). It has not been observed previously, although the {\alpha}
particle was identified a century ago by Rutherford and is present in cosmic
radiation at the 10% level. Antimatter nuclei with B < -1 have been observed
only as rare products of interactions at particle accelerators, where the rate
of antinucleus production in high-energy collisions decreases by about 1000
with each additional antinucleon. We present the observation of the antimatter
helium-4 nucleus, the heaviest observed antinucleus. In total 18
counts were detected at the STAR experiment at RHIC in 10 recorded Au+Au
collisions at center-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon
pair. The yield is consistent with expectations from thermodynamic and
coalescent nucleosynthesis models, which has implications beyond nuclear
physics.Comment: 19 pages, 4 figures. Submitted to Nature. Under media embarg
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