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.

Discovery of a Galaxy Cluster in the Foreground of the Wide-Separation Quasar Pair UM425

We report the discovery of a cluster of galaxies in the field of UM425, a pair of quasars separated by 6.5arcsec. Based on this finding, we revisit the long-standing question of whether this quasar pair is a binary quasar or a wide-separation lens. Previous work has shown that both quasars are at z=1.465 and show broad absorption lines. No evidence for a lensing galaxy has been found between the quasars, but there were two hints of a foreground cluster: diffuse X-ray emission observed with Chandra, and an excess of faint galaxies observed with the Hubble Space Telescope. Here we show, via VLT spectroscopy, that there is a spike in the redshift histogram of galaxies at z=0.77. We estimate the chance of finding a random velocity structure of such significance to be about 5%, and thereby interpret the diffuse X-ray emission as originating from z=0.77, rather than the quasar redshift. The mass of the cluster, as estimated from either the velocity dispersion of the z=0.77 galaxies or the X-ray luminosity of the diffuse emission, would be consistent with the theoretical mass required for gravitational lensing. The positional offset between the X-ray centroid and the expected location of the mass centroid is about 40kpc, which is not too different from offsets observed in lower redshift clusters. However, UM425 would be an unusual gravitational lens, by virtue of the absence of a bright primary lensing galaxy. Unless the mass-to-light ratio of the galaxy is at least 80 times larger than usual, the lensing hypothesis requires that the galaxy group or cluster plays a uniquely important role in producing the observed deflections. Based on observations performed with the Very Large Telescope at the European Southern Observatory, Paranal, Chile.Comment: 12 pages, accepted by ApJ 2005, May 1

The Parametrized Post-Newtonian-Vainshteinian formalism

Light degrees of freedom that modify gravity on cosmological scales must be "screened" on solar system scales in order to be compatible with data. The Vainshtein mechanism achieves this through a breakdown of classical perturbation theory, as large interactions involving new degrees of freedom become important below the so-called Vainshtein radius. We begin to develop an extension of the Parameterized Post-Newtonian (PPN) formalism that is able to handle Vainshteinian corrections. We argue that theories with a unique Vainshtein scale must be expanded using two small parameters. In this Parameterized Post-Newtonian-Vainshteinian (PPNV) expansion, the primary expansion parameter that controls the PPN order is, as usual, the velocity v. The secondary expansion parameter, α, controls the strength of the Vainshteinian correction and is a theory-specific combination of the Schwarzschild radius and the Vainshtein radius of the source that is independent of its mass. We present the general framework and apply it to Cubic Galileon theory both inside and outside the Vainshtein radius. The PPNV framework can be used to determine the compatibility of such theories with solar system and other strong-field data

Evaluating the Effectiveness of Game-Based Virtual Reality in Satellite Ground Control Operations Education and Training

There is increased global demand for satellite amenities such as navigation, communications, weather reporting, disaster management, agricultural operations, or humanitarian assistance. The growing demand for satellite technology amplifies the need for highly trained satellite operators. Traditional simulation training methods typically utilize two-dimensional computer displays. However, training approaches involving game-based instruction and immersive virtual reality have shown benefits when integrated with complex disciplines and may provide an advanced training alternative for satellite operators. Game-based instruction enhances user motivation and cognitive engagement, while immersive virtual reality promotes user presence and prolonged cognitive engagement. The combination of these two training methods, noted as game-based virtual reality, is explored in this study when integrated with a satellite operator training scenario. The study compares two groups, one training with traditional methods and one with game-based virtual reality. Both scenarios indicated significant usability scores and proper cognitive loading necessary for meaningful learning, with only minimal symptoms of simulator sickness. However, unlike the traditional method, the results of the game-based virtual reality scenario revealed significant user enjoyment and satisfaction scores. A positive and satisfying learning experience can facilitate enhanced motivation and increased cognitive engagement, fundamental to meaningful learning, denoting game-based virtual reality as a viable and effective training alternative

YRuO3: A quantum weak ferromagnet

International audienceThe perovskite YRuO 3 containing low-spin d 5 Ru 3+ has a Pnma orthorhombic structure with elongated RuO 6 octahedra evidencing orbital order and is insulating to low temperatures with a band gap of 70 meV. Canted antiferromagnetic Ru 3+ spin order is observed below T C = 97 K, and magnetization plateaus that emerge below 62 K reveal a quantum weak ferromagnetic state where 1/8 of the spins are reversed, reflecting extreme singleion anisotropy resulting from the strong spin-orbit coupling of the d 5 Ru 3+ ion. Dynamic effects of the reversed spins give rise to an unusual negative AC susceptibility response, and a partial freezing of this motion occurs at 27 K

Analysis of the regional efficiency of european funds in Spain from the perspective of renewable energy production: The regional dimension

During the 2010–2020 period, the European Union (EU) launched a growth strategy based on three fundamental pillars: Smart growth, sustainable growth, and inclusive growth. Aiming to finance the projects related to these growth pillars, the EU used mainly the Rural Development Funds, the Structural Funds, those derived from the R&D Framework Program, the Trans-European Networks, and the European Investment Bank. This research aimed to determine whether the Spanish regions maintain homogeneous efficiency levels by using these resources to improve the levels of environmental quality related to renewable energies. A methodology that is frequently used by researchers in efficiency analyses was chosen, the Data Envelopment Analysis (DEA). The main findings revealed that the efficiency in the use of renewable energies is very uneven among the Spanish regions and these differences are maintained throughout the period analyzed. These results highlighted the need of changes regarding the proposed criteria for allocating European resources to finance the projects presented by each Spanish regio

Complex Ferrimagnetism and Magnetoresistance Switching in Ca-Based Double Double and Triple Double Perovskites

Cation ordering in ABO₃ perovskites can lead to interesting and useful phenomena such as ferrimagnetism and high magnetoresistance by spin polarized conduction in Sr₂FeMoO₆. We used high pressures and temperatures to synthesize the cation ordered AA′BB′O₆ perovskites CaMnFeReO₆, CaMnMnReO₆, and Ca­(Mn_0.5Cu_0.5)­FeReO₆. These have columnar A/A′ and rocksalt B/B′ cation orders, as found in the recently discovered double double perovskite MnNdMnSbO₆, and partial Mn/Cu order over tetrahedral and square planar A′ sites in Ca­(Mn_0.5Cu_0.5)­FeReO₆ demonstrates that triple double cation order is possible. Neutron diffraction reveals complex ferrimagnetic orders in all three materials; CaMnFeReO₆ and Ca­(Mn_0.5Cu_0.5)­FeReO₆ have large room temperature magnetizations with low temperature switching of magnetoresistance in the latter material, and CaMnMnReO₆ displays a high coercivity of 1.3 T at low temperatures

Interwoven magnetic and flux line structures in single crystal (Tm,Er)Ni2B2C

We review studies of the interactions between magnetic order and the flux line lattice (FLL) in the (RE)Ni2B2Cintermetallic borocarbides for (RE)=Tm and Er using small angle neutron scattering (SANS) and magneto-transport. For (RE)=Tm the magnetic order and the FLL assume a common symmetry, sharing a phase transition at ∼2 kOe, despite an order of magnitude difference in periodicity. For (RE)=Er, the penetration depth λ and the coherence length ξ, both of which are derived from the FLL form factor, are modified near TN=6 K by a theoretically predicted weakly divergent pairbreaking. Finally, below 2.3 K, (RE)=Er shows a coexistence of weak ferromagnetism and superconductivity. This state reveals a highly disordered FLL and a striking increase in the critical current, both arising from the strong ferromagnetic pairbreaking