80,647 research outputs found
Short Note on the Unemployment Rate of the French Overseas Regions
This article analyzes the hysteresis hypothesis in the unemployment rates of the four French overseas regions (Guadeloupe, Martinique, Guyana, Reunion) [FORs] over the period 1993-2008. We use standard univariate and panel unit root tests, among them Choi (2006) and Lopez (2009) that account for cross-sectional dependence and have improved performance when the number of countries and the time dimension of the data are limited. Our results cannot reject the null hypothesis of a unit root and so find evidence supporting hysteresis in the unemployment rates for the FORs.panel unit root, unemployment, hysteresis.
Magnetic ordering in GdNi2B2C revisited by resonant x-ray scattering: evidence for the double-q model
Recent theoretical efforts aimed at understanding the nature of
antiferromagnetic ordering in GdNi2B2C predicted double-q ordering. Here we
employ resonant elastic x-ray scattering to test this theory against the
formerly proposed, single-q ordering scenario. Our study reveals a satellite
reflection associated with a mixed-order component propagation wave vector,
viz., (q_a,2q_b,0) with q_b = q_a approx= 0.55 reciprocal lattice units, the
presence of which is incompatible with single-q ordering but is expected from
the double-q model. A (3q_a,0,0) wave vector (i.e., third-order) satellite is
also observed, again in line with the double-q model. The temperature
dependencies of these along with that of a first-order satellite are compared
with calculations based on the double-q model and reasonable qualitative
agreement is found. By examining the azimuthal dependence of first-order
satellite scattering, we show the magnetic order to be, as predicted,
elliptically polarized at base temperature and find the temperature dependence
of the "out of a-b plane" moment component to be in fairly good agreement with
calculation. Our results provide qualitative support for the double-q model and
thus in turn corroborate the explanation for the "magnetoelastic paradox"
offered by this model.Comment: 8 pages, 5 figures. Submitted to Phys. Rev.
Field Dependence of the Superconducting Basal Plane Anisotropy of TmNi2B2C
The superconductor TmNi2B2C possesses a significant four-fold basal plane
anisotropy, leading to a square Vortex Lattice (VL) at intermediate fields.
However, unlike other members of the borocarbide superconductors, the
anisotropy in TmNi2B2C appears to decrease with increasing field, evident by a
reentrance of the square VL phase. We have used Small Angle Neutron Scattering
measurements of the VL to study the field dependence of the anisotropy. Our
results provide a direct, quantitative measurement of the decreasing
anisotropy. We attribute this reduction of the basal plane anisotropy to the
strong Pauli paramagnetic effects observed in TmNi2B2C and the resulting
expansion of vortex cores near Hc2.Comment: 8 pages, 6 figures, 1 tabl
Traveling waves in rotating Rayleigh-BĂ©nard convection: Analysis of modes and mean flow
Numerical simulations of the Boussinesq equations with rotation for realistic no-slip boundary conditions and a finite annular domain are presented. These simulations reproduce traveling waves observed experimentally. Traveling waves are studied near threshhold by using the complex Ginzburg-Landau equation (CGLE): a mode analysis enables the CGLE coefficients to be determined. The CGLE coefficients are compared with previous experimental and theoretical results. Mean flows are also computed and found to be more significant as the Prandtl number decreases (from sigma=6.4 to sigma=1). In addition, the mean flow around the outer radius of the annulus appears to be correlated with the mean flow around the inner radius
Kondo Breakdown and Hybridization Fluctuations in the Kondo-Heisenberg Lattice
We study the deconfined quantum critical point of the Kondo-Heisenberg
lattice in three dimensions using a fermionic representation for the localized
spins. The mean-field phase diagram exhibits a zero temperature quantum
critical point separating a spin liquid phase where the hybridization vanishes
and a Kondo phase where it does not. Two solutions can be stabilized in the
Kondo phase, namely a uniform hybridization when the band masses of the
conduction electrons and the spinons have the same sign, and a modulated one
when they have opposite sign. For the uniform case, we show that above a very
small temperature scale, the critical fluctuations associated with the
vanishing hybridization have dynamical exponent z=3, giving rise to a
resistivity that has a T log T behavior. We also find that the specific heat
coefficient diverges logarithmically in temperature, as observed in a number of
heavy fermion metals.Comment: new Figure 2, new results on spin susceptibility, some minor changes
to tex
A Group of Red, Ly-alpha Emitting, High Redshift Galaxies
We have discovered two new high redshift (z=2.38) galaxies, near the
previously known z=2.38 galaxy 2139-4434 B1 (Francis et al. 1996).
All three galaxies are strong Ly-alpha emitters, and have much redder
continuum colors (I-K about 5) than other optically-selected high redshift
galaxies. We hypothesize that these three galaxies are QSO IIs; radio-quiet
counterparts of high redshift radio galaxies, containing concealed QSO nuclei.
The red colors are most easily modelled by an old (> 0.5 Gyr), massive (> 10E11
solar masses) stellar population. If true, this implies that at least one
galaxy cluster of mass much greater than 3E11 solar masses had collapsed before
redshift five.Comment: 12 pages, 2 figures, uses aaspp4 style file. Accepted for publication
in Astrophysical Journal Letter
Improving clerkship preparedness: a hospital medicine elective for pre-clerkship students.
BackgroundMedical students often struggle to apply their nascent clinical skills in clerkships. While transitional clerkships can orient students to new roles and logistics, students may benefit from developing clinical skills in inpatient environments earlier in their curriculum to improve readiness for clerkships.InterventionOur four- to six-session elective provides pre-clerkship students with individualized learning in the inpatient setting with the aim of improving clerkship preparedness. Students work one-on-one with faculty who facilitate individualized learning through mentoring, deliberate practice, and directed feedback. Second-year medical students are placed on an attending-only, traditionally 'non-teaching' service in the hospital medicine division of a Veterans Affairs (VA) hospital for half-day sessions. Most students self-select into the elective following a class-wide advertisement. The elective also accepts students who are referred for remediation of their clinical skills.OutcomeIn the elective's first two years, 25 students participated and 47 students were waitlisted. We compared participant and waitlisted (non-participant) students' self-efficacy in several clinical and professional domains during their first clerkship. Elective participants reported significantly higher clerkship preparedness compared to non-participants in the areas of physical exam, oral presentation, and formulation of assessments and plans.ConclusionsStudents found the one-on-one feedback and personalized attention from attending physicians to be a particularly useful aspect of the course. This frequently cited benefit points to students' perceived needs and the value they place on individualized feedback. Our innovation harnesses an untapped resource - the hospital medicine 'non-teaching' service - and serves as an attainable option for schools interested in enhancing early clinical skill-building for all students, including those recommended for remediation.AbbreviationsA&P: Assessment and plan; H&P: History and physical; ILP: Individual learning plan
- …