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Dunkerque, France

University of the Littoral Opal Coast , also known as ULCO, is a French university, based in Dunkerque. It reports to the Academy of Lille and is a member of the European Doctoral College Lille-Nord-Pas de Calais.ULCO is situated in Pas-de-Calais, in the north of France, north west of Lille. The full name is "Université du Littoral - Côte d'Opale". The university is divided in four parts, in four cities: Boulogne sur Mer Calais Dunkerque Saint-OmerIt was created in 1991; the first year of studies was in 1992. Several degrees are granted there, and the university was integrated in the European Space of Higher Education in 2004 . Wikipedia.

Dupre P.,University of the Littoral Opal Coast
Journal of the Optical Society of America B: Optical Physics

An analytical methodology is presented to calculate spectra provided by NICE-OHMS. It is based on the solutions of the equations of motion of an open two-blocked-level system performed in the frequency domain. The polychromaticity of the impinging electromagnetic field, furthermore, trapped inside a high-finesse cavity, is a potential source of induced resonances when this field interacts with a weakly absorbing nonlinear medium. These are optimal conditions to produce the well-established hole burning. However, the radio-frequency sidebands intrinsically associated with the NICE-OHMS technique require a specific treatment for describing both absorption and optical phase shift contributions. To validate the approach, numerical simulations of two transitions of C2H2 in the near-infrared range are discussed. The Doppler broadening-free cross-sideband resonances have been clearly characterized under the regime of moderate electromagnetically induced saturation. Comparison to experimental data available [Opt. Express 16, 14689 (2008)] allowed us to assess the eligibility of the approach. © 2015 Optical Society of America. Source

Efstathiou K.,University of Groningen | Sadovskii D.A.,University of the Littoral Opal Coast
Reviews of Modern Physics

The hydrogen atom perturbed by sufficiently small homogeneous static electric and magnetic fields of arbitrary mutual alignment is a specific perturbation of the Kepler system with three degrees of freedom and three parameters. Normalization of the Keplerian symmetry reveals that the parameter space is stratified into resonant zones of systems, each zone with an internal dynamical stratification of its own (Efstathiou, Sadovskií, and Zhilinskií, 2007, Proc. R. Soc. London, Ser. A 463, 177110.1098/rspa. 2007.1843). Based on the fully integrable approximation, the bundle of invariant tori of individual systems within zones is characterized globally and the qualitative dynamical stratification is uncovered. The techniques involved in this analysis are illustrated with the example of the 1:1 resonance zone (near orthogonal fields) whose structure is known at present. Applications in the corresponding quantum system are also described. © 2010 The American Physical Society. Source

Stubbe I.,University of the Littoral Opal Coast
Fuzzy Sets and Systems

In the context of quantaloid-enriched categories, we rely essentially on the classifying property of presheaf categories to give a conceptual proof of a theorem due to Höhle: the double power monad and the composite power monad, on the category of quantaloid-enriched categories, are the same. Via the theory of distributive laws, we identify the algebras of this monad to be the completely codistributive complete categories, and the homomorphisms between such algebras are the bicontinuous functors. With these results we hope to contribute to the further development of a theory of Q-valued preorders (in the sense of Pu and Zhang). © 2016 Elsevier B.V. Source

Vanhelst J.,University of the Littoral Opal Coast
Journal of sports sciences

The aim of this study was to assess the reliability of the RT3 accelerometer under conditions of normal physical activity. Sixty healthy individuals (30 boys, 30 girls) aged 10-16 years wore two accelerometers while performing different structured physical activities. The accelerometers were synchronized and data were recorded every minute during nine 15-min sessions of physical activity that varied in intensity from sedentary (watching television, playing video games) to vigorous (running on a treadmill at different speeds). Intra-instrument coefficients of variation (CV) were assessed using the formula CV = standard deviation of the measure x 100/mean of the measure. The intra-instrument coefficient of variation was higher for sedentary (17%) and light activity (16.2%) than moderate (9.3%) and vigorous activity (6.6%). These results confirmed the poor reliability of the RT3 for activity of low magnitude and frequency that was demonstrated in studies using a shaker. Source

Vanhelst J.,University of the Littoral Opal Coast
Journal of sports sciences

The aim of this study was to determine thresholds for various intensities of physical activity in children and adolescents using the RT3 accelerometer. Forty healthy participants aged 10-16 years were recruited to the study. To validate the RT3 accelerometer data, an independent sample of 20 children and adolescents aged 10-16 years performed the same activities. Accelerometer data, heart rate, and oxygen consumption were measured at nine levels of physical activity, which varied in intensity: sedentary, light, moderate, and vigorous. Age and sex did not affect thresholds. The activity categories and accelerometer counts were: sedentary activity, 0-40 counts x min(-1); light activity, 41-950 counts x min(-1); moderate activity, 951-3410 counts x min(-1); and vigorous activity, >3410 counts x min(-1), respectively. These thresholds were considered valid as the difference between threshold values obtained using two independent groups of children was not significant. This study has established threshold values for various physical activities and enables the RT3 accelerometer to be used to quantify the duration of various levels of activity in adolescents under free-living conditions. Source

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