Number theory in the national compulsory examination at the end of the French secondary level: between organizing and operative dimensions

International audienceIn our researches in didactic of number theory, we are especially interested in proving in the secondary-tertiary transition. In this paper, we focus on the "baccalauréat", the national examination that pupils have to take at the end of French secondary level. In reasoning in number theory, we distinguish two complementary dimensions, namely the organising one and the operative one, and this distinction permits to situate the autonomy devolved to learners in number theory problems such as baccalauréat's exercises. We have analysed 38 exercises, from 1999 to 2008, and we present the results obtained giving emblematic examples

Stop Using the Modified Work APGAR to Measure Job Satisfaction

Background. The psychometric properties of the Modified Work APGAR (MWA) scale are not established, yet researchers use this scale as an overall measure of job satisfaction. Objective. Perform psychometric analyses on the MWA scale using data from two populations. Methods. A landmark occupational cohort and a clinical cohort are populations with low back pain studied. The first five items of the MWA scale measure social support from coworkers, one item measures dissatisfaction with job tasks, and the sixth item measures lack of social support from a supervisor. Exploratory principal components analyses were conducted in both cohorts. Results. In both cohorts, the first five items of the MWA scale loaded consistently onto one factor, social support from coworkers subscale. Conclusions. Unless researchers are interested in measuring social support from coworkers only, future studies should use other reliable and valid instruments to measure a broad range of psychosocial work characteristics

Diameter dependence of the optoelectronic properties of single walled carbon nanotubes determined by ellipsometry

International audienceWe report ellipsometric measurement on single walled carbon nanotube (SWCNT) films performed in a large spectral range from 0.07eV to 4.97eV. The complex dielectric functions of SWCNTs are correlated to their diameter distribution extracted from transmission electron microscopy. Here we show that the transition energies between Van Hove singularities are directly related to the strong one dimensional confinement. In the infrared spectral range, the real part of the dielectric function becomes negative. The electronic properties of SWCNTs are extracted from ellipsometry by using a Drude model. The mobility and the mean free path of charge carriers are limited by the high number of SWCNT contacts. In accordance with tight binding simulation, the conductivity and the charge carrier concentration increase with the SWCNT diameter. Finally, we demonstrate that the S-plasmon energy depends on the charge carrier concentration.

Optimized Flight Preparation Process for the First Vega Ride-Share Mission

The first European ride-share mission will be carried out by the Vega launch system in mid 2019. The VEGA PoC (Proof of Concept) flight using the SSMS (Small Satellite Mission Service) hardware was conceived in the context of ESA LLL Initiative. This paper describes the Light Sats aggregate selection process and the preparation of the first European ride-share mission with Vega launcher, update on the hardware preparation status and provide insight on the methods and tools used for its implementation. Based on Vega flights accumulated experience, the development of multi-Payload mission concept started from analysis of the activities currently foreseen to fly a single payload mission adapted to the needs multi payload rideshare missions. Evaluation of impacts in terms of technical feasibility, missioning schedule and related programmatic and cost elements where considered for the missioning of the Light Sats launch service. Major elements of the process described in this paper envelope mission analysis, launch preparation including AIT approach and launch service aspects with customers, before and after launch service agreement signature. The described process is intended to constitute a first step using the Vega launch system, useful towards the ultimate goal to support the definition of a finally optimized process applicable to all European launchers

The First Vega Ride-Share Mission Flight

The first European ride-share mission will be carried out by the Vega launch system in September 2019. The VEGA PoC (Proof of Concept) flight using the SSMS (Small Satellite Mission Service) hardware was conceived in the context of ESA LLL Initiative. This paper reports on the highlights of the preparation of the first European rideshare mission with Vega launcher and on the development of the related launch system. Based on Vega flights accumulated experience, the development of multi-Payload mission concept started from analysis of the activities currently foreseen to fly a single payload mission adapted to the needs of multi payload rideshare missions. After evaluation of impacts in terms of technical feasibility, missioning schedule and related programmatic and cost elements for the missioning of the Light Sats launch service, the implementation phase was initiated and description of its major tasks is the focus of this paper. The described hardware development and processes to reach SSMS PoC flight using the Vega launch system, are the first step towards the ultimate goal of a finally optimized process for Light Sats ride-share missions applicable to all European launchers

Improvement of lower extremity electrodiagnostic findings following a trial of spinal manipulation and motion-based therapy

BACKGROUND: Lumbar disc herniation is a problem frequently encountered in manual medicine. While manual therapy has shown reasonable success in symptomatic management of these cases, little information is known how manual therapy may affect the structure and function of the lumbar disc itself. In cases where lumbar disc herniation is accompanied by radicular symptoms, electrodiagnostic testing has been used to provide objective clinical information on nerve function. This report examines the treatment rendered for a patient with lower extremity neurological deficit, as diagnosed on electrodiagnostic testing. Patient was treated using spinal manipulation and exercises performed on a Pettibon Wobble Chair™, using electrodiagnostic testing as the primary outcome assessment. CASE PRESENTATION: An elderly male patient presented to a private spine clinic with right-sided foot drop. He had been prescribed an ankle-foot orthosis for this condition. All sensory, motor, and reflex findings in the right leg and foot were absent. This was validated on prior electromyography and nerve conduction velocity testing, performed by a board certified neurologist. Patient was treated using spinal manipulation twice-weekly and wobble chair exercises three times daily for 90 days total. Following this treatment, the patient was referred for follow-up electrodiagnostic studies. Significant improvements were made in these studies as well as self-rated daily function. CONCLUSION: Motion-based therapies, as part of a comprehensive rehabilitation program, may contribute to the restoration of daily function and the reversal of neurological insult as detected by electrodiagnostic testing. Electrodiagnostic testing may be a useful clinical tool to evaluate the progress of chiropractic patients with lumbar disc herniation and radicular pain syndromes