2,744 research outputs found
Globalization and Inflation Dynamics: the Impact of Increased Competition
This paper analyzes the potential effect of global market competition on inflation dynamics. It does so through the lens of the Calvo model of staggered price-setting, which implies that inflation depends on expected future inflation and a measure of marginal costs. I modify the assumption of a constant elasticity of demand, standard in this model, to provide a channel through which an increase in the number of traded goods may affect the degree of strategic complementarity in price setting, and hence alter the dynamic response of inflation to marginal costs. I first discuss the behavior of the variables that drive the impact of trade openness on this response, and then I evaluate whether an increase in the variety of traded goods of the size observed in the US in the `90s might have a sizable quantitative impact. I find that it is difficult to argue that such an increase in trade should have generated an increase in US market competition leading to a decline in the slope of the inflation-marginal cost relation.
Clinical survey of neurosensory side-effects of mandibular parasymphyseal bone harvesting
The aim of the present survey was to assess neurosensory disturbances and/or tooth-pulp sensitivity losses after mandibular parasymphyseal bone-harvesting procedures. Twenty-eight harvesting areas in 16 patients were surveyed. Mucosal and skin sensitivity of the chin/lower lip, divided into four regions, were determined via Pointed-Blunt and Two-Point-Discrimination Tests. Pulp sensitivity of the mandibular teeth from the left second bicuspid to the right second bicuspid was tested by cold vitality preoperatively and 12 months postoperatively. Teeth were grouped according to sensitivity alterations and distance from the harvesting defects, as measured on CT scans, and statistically significant differences sought. At 12 months, 29% of preoperatively vital cuspids overlying the harvesting defects revealed pulp-sensitivity losses; no patient reported anaesthesia or analgesia; hypoaesthesia was present in 4% (8 sites; 2 patients), hypoalgesia was present in 3% (5 sites; 2 patients) and Two-Point-Discrimination Tests yielded pathologic responses in 5% of tested areas (10 sites; 4 patients). Teeth with and without pulp sensitivity changes were statistically indistinguishable regarding distances between root apices or mental foramen and the harvesting defect. The loss of pulp sensitivity in any tooth cannot be predicted simply on the basis of the distance between its apex and the harvesting osteotomy line
Lithium abundances in extremely metal-poor turn-off stars
We discuss the current status of the sample of Lithium abundances in
extremely metal poor (EMP) turn-off (TO) stars collected by our group, and
compare it with the available literature results. In the last years, evidences
have accumulated of a progressive disruption of the Spite plateau in stars of
extremely low metallicity. What appears to be a flat, thin plateau above
[Fe/H]\sim-2.8 turns, at lower metallicities, into a broader distribution for
which the plateau level constitutes the upper limit, but more and more stars
show lower Li abundances. The sample we have collected currently counts
abundances or upper limits for 44 EMP TO stars between [Fe/H]=-2.5 and -3.5,
plus the ultra-metal poor star SDSS J102915+172927 at [Fe/H]=-4.9. The
"meltdown" of the Spite plateau is quite evident and, at the current status of
the sample, does not appear to be restricted to the cool end of the effective
temperature distribution. SDSS J102915+172927 displays an extreme Li depletion
that contrasts with its otherwise quite ordinary set of [X/Fe] ratios.Comment: 6 pages, 4 figures, proceedings of the "Lithium in the Cosmos"
conference, Paris, 27-29 February 201
Globular Cluster Abundances and What They Can Tell Us About Galaxy Formation
We review the properties of globular clusters which make them useful for
studying the Galactic halo, Galactic chemical evolution, and the early stages
of the formation of the Milky Way. We review the evidence that GCs have a
chemical inventory similar to those of halo field stars. We discuss the
abundance ratios for dSph galaxies and show that it is possible to have formed
at least part the Galactic halo field stellar population by dissolving globular
clusters and/or accreting dSph galaxies but only if this occurred at an early
stage in the formation of the Galaxy. We review the constraints on halo
formation timescales deduced from the low Mg isotopic ratios in metal-poor halo
field dwarfs which indicate that AGB stars did not have time to contribute
significantly, while M71 contains two populations, one without and also one
with a substantial AGB contribution. We review the limited evidence for GCs
with a second population showing additional contributions from SNII, currently
confined to Omega Cen, M54, and M22, all of which may have been the nuclei or
central regions of accreted galaxies. We check our own data for additional such
GCs, and find preliminary indications that NGC 2419, a massive GC far in the
outer Galactic halo, may also belong to this group.Comment: Invited Talk: IAU Symp. 266, Star Clusters - Basic Building Blocks
Throughout Time and Space, proceedings to be published by Cambridge
University Pres
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