Psychometric validation of the French version of the Connor-Davidson Resilience Scale.

OBJECTIVES: Resilience defines the ability to face adversity with positive outcomes. Different scales, including the 25-item Connor-Davidson Resilience Scale (CDRISC), have been elaborated in order to evaluate resilience among various populations. The evaluation of resilience in French populations was impossible until CDRISC was translated into French. In the present work, we aim to validate a French version of CDRISC (f-CDRISC). METHODS: The survey was conducted at Nantes University. Both dental and medical students were eligible. The factor structure of f-CDRISC was determined and its replicability was tested on two sub-samples by exploratory factor analysis (EFA) and parallel analysis (PA). A third student sample was used for confirmatory factorial analysis (CFA). RESULTS: We collected 1210 responses. Four items did not reach acceptance thresholds for reliability and were discarded from the f-CDRISC. EFA and PA of the remaining 21 items highlighted a replicable 3-factor structure that was further confirmed by CFA. Resilience factors included "tolerance to negative affects", "tenacity" and "self-confidence". All factors displayed acceptable to good internal consistency. They were characterized by positive medium to strong correlations with the overall f-CDRISC Scale. Significant positive correlations were also observed between the resilience factors. CONCLUSION: The present work constitutes the first study devoted to a French adaptation of the CDRISC questionnaire. We present evidence showing that the f-CDRISC is a reliable tool for resilience evaluation in French speaking populations.

Laboratory analogue of a supersonic accretion column in a binary star system.

Astrophysical flows exhibit rich behaviour resulting from the interplay of different forms of energy-gravitational, thermal, magnetic and radiative. For magnetic cataclysmic variable stars, material from a late, main sequence star is pulled onto a highly magnetized (B>10 MG) white dwarf. The magnetic field is sufficiently large to direct the flow as an accretion column onto the poles of the white dwarf, a star subclass known as AM Herculis. A stationary radiative shock is expected to form 100-1,000 km above the surface of the white dwarf, far too small to be resolved with current telescopes. Here we report the results of a laboratory experiment showing the evolution of a reverse shock when both ionization and radiative losses are important. We find that the stand-off position of the shock agrees with radiation hydrodynamic simulations and is consistent, when scaled to AM Herculis star systems, with theoretical predictions.

Supersonic-jet experiments using a high-energy laser.

In this Letter, laboratory astrophysical jet experiments performed with the LULI2000 laser facility are presented. High speed plasma jets (150 km.s(-1)) are generated using foam-filled cone targets. Accurate experimental characterization of the plasma jet is performed by measuring its time evolution and exploring various target parameters. Key jet parameters such as propagation and radial velocities, temperature, and density are obtained. For the first time, the required dimensionless quantities are experimentally determined on a single-shot basis. Although the jets evolve in vacuum, most of the scaling parameters are relevant to astrophysical conditions.

Observation of laser driven supercritical radiative shock precursors.

We present a supercritical radiative shock experiment performed with the LULI nanosecond laser facility. Using targets filled with xenon gas at low pressure, the propagation of a strong shock with a radiative precursor is evidenced. The main measured shock quantities (electronic density and propagation velocity) are shown to be in good agreement with theory and numerical simulations.