L'internat avec école aux limites du projet scolaire inclusif: module Travail de Master

Ce travail vise à présenter la position de l'"internat avec école", structure en charge d'enfants en danger de maltraitance ou maltraités et présentant des troubles du comportement, dans un contexte légal et de pratiques professionnelles qui valorisent l'intégration scolaire et tendanciellement l'inclusion de tous les élèves dans l'école obligatoire. Des préconisations concrètes visant à orienter la pratique de direction de l'internat avec école sont présentées dans la partie conclusive

Isotope shift in the Sulfur electron affinity: observation and theory

The electron affinities eA(S) are measured for the two isotopes 32S and 34S (16752.9753(41) and 16752.9776(85) cm-1, respectively). The isotope shift in the electron affinity is found to be positive, eA(34S)-eA(32S) = +0.0023(70) cm-1, but the uncertainty allows for the possibility that it may be either "normal" (eA(34S) > eA(32S)) or "anomalous" (eA(34S) < eA(32S)). The isotope shift is estimated theoretically using elaborate correlation models, monitoring the electron affinity and the mass polarization term expectation value. The theoretical analysis predicts a very large specific mass shift that counterbalances the normal mass shift and produces an anomalous isotope shift, eA(34S)-eA(32S) = - 0.0053(24) cm-1. The observed and theoretical residual isotope shifts agree with each other within the estimated uncertainties.Comment: 15 pages, 4 figure

Metrology of the Acoustic Seafloor Response:How to accurately estimate backscatter and its intrinsic uncertainty using single-beam echosounder

Its measurements have been widely extended in hydrography using predominantly bathymetric echosounders, and they are used in diverse applications such as habitat mapping, seabed characterisation or classification. In recent decades, numerous theoretical models have also been developed to study its link with physical or heuristic bottom parameters. While analysing how these three domains (measurement, application, and theory) deal with the seafloor acoustic response, it appeared that the nature itself of the seafloor acoustic response is equivocal.The work presented here proposes a relationship between the three uses of the seafloor acoustic response. Based on statistical and physical hypotheses, a metrological method is established, connecting seafloor response measurements, applications and theory. In particular, the deterministic backscatter parameter derived theoretically is usefully linked to the stochastic nature observed in practice during backscatter measurements. This yieldsa method for accurately estimating backscatter values from bathymetric echosounder data: the best choice of backscatter estimator is justified based on analytical calculations, and ways to represent its uncertainties are proposed. Theoretical hypotheses are validated using real data from handmade single-beam echosounders tested at ENSTA Bretagne (France) and at the University of Bath (UK). After application of the method to survey data, its benefits, limits, and future implementation are discussed

Marine observations with a harmonic single-beam echo-sounder

International audienceTo characterise the seabed or water-column targets with acoustics, it is common to use multiple frequencies and therefore several sonar transducers or echo-sounders. The single beam echo-sounder we present here is able, thanks to non-linearity of the sea water, to generate more than three harmonics above its fundamental transmitted frequency, in effect producing four distinct frequencies with a single echo-sounder. In addition, all transmitted signals are perfectly in phase because they are carried by the same pulse, which has obvious benefits for further processing of the echoes. In this presentation, after a short review of the entire system, its application to seabed characterisation using the reflectivity level (acoustic backscattering strength from the seafloor) will be exposed. Further developments of plans to use this echo-sounder for fishery acoustics will then be highlighted, based on datasets acquired in the Bay of Brest (France). (Project funded by ANR and DGA / ANR-14-ASTR-0022-00)

New hippotragini (Bovidae, Mammalia) from the Late Miocene of Toros-Menalla (Chad)

International audienceUntil now, the pre-Pleistocene record of the bovid tribe Hippotragini was rather poor. We describe here two new taxa from the late Miocene of Toros-Menalla in northern Chad, which yielded the earliest known hominid, Sahelanthropus tchadensis. Tchadotragus sudrei n.gen. n.sp. is known by complete skulls and numerous horn-cores. It has typical hippotragine features such as long slender, curved horn-cores, weak cranial flexure, large frontal sinus, and hippotragine-like dentition, and is here taken as a basal member of the tribe, branching before the divergence between Oryx-Praedamalis and Hippotragus s.l. Saheloryx solidus n.gen. n.sp. is less well-known; it differs mainly by the lack of sinus in the frontal and horn-cores, shorter horn-cores, and rounded brain-case, but it shares with Tchadotragus a large number of features that prompt us to classify it also at the base of the hippotragine tree, perhaps as the sister-taxon of Tchadotragus. No other African taxon looks like Saheloryx, and the only one similar to Tchadotragus is from Sahabi, Libya. The abundance of hippotragines sharply distinguishes Toros-Menalla from the East African late Miocene bovid faunas

Comparison of methods employed to extract information contained in seafloor backscatter

International audienceSeabed maps are based on quantities extracted from measurements of the seafloor‘s acoustic response by sonar systems such as single-beam echo-sounders (SBES), multibeam echo-sounders (MBES) or sidescan sonars (SSS). In this paper, a comparison of various strategies to estimate the backscattering strength (BS) from recorded time-series, i.e. seabed echoes extracted from pings, is presented. The work hypotheses are based on processed data from a SBES designed to be tilted mechanically. Ideal survey conditions are taken into account and the seafloor is supposed to be rough so that BS is assumed to be equivalent to the Rayleigh probability density function parameter. Classical methods such as averaging corrected (sonar equation) backscattered single values over a set of pings to estimate BS are compared to other methods exploiting several time-samples being part of pings. Simulated data is considered to estimate BS in different situations (several estimators, natural/squared values, number of samples and pings). The best estimator to reach a 0.1dB uncertainty is proposed, and a formula governing the number of time-samples and pings needed to reach an accurate BS estimation according to the measurement conditions is derived

Metrology of the Acoustic Seafloor Response:How to accurately estimate backscatter and its intrinsic uncertainty using single-beam echosounder

Its measurements have been widely extended in hydrography using predominantly bathymetric echosounders, and they are used in diverse applications such as habitat mapping, seabed characterisation or classification. In recent decades, numerous theoretical models have also been developed to study its link with physical or heuristic bottom parameters. While analysing how these three domains (measurement, application, and theory) deal with the seafloor acoustic response, it appeared that the nature itself of the seafloor acoustic response is equivocal.The work presented here proposes a relationship between the three uses of the seafloor acoustic response. Based on statistical and physical hypotheses, a metrological method is established, connecting seafloor response measurements, applications and theory. In particular, the deterministic backscatter parameter derived theoretically is usefully linked to the stochastic nature observed in practice during backscatter measurements. This yieldsa method for accurately estimating backscatter values from bathymetric echosounder data: the best choice of backscatter estimator is justified based on analytical calculations, and ways to represent its uncertainties are proposed. Theoretical hypotheses are validated using real data from handmade single-beam echosounders tested at ENSTA Bretagne (France) and at the University of Bath (UK). After application of the method to survey data, its benefits, limits, and future implementation are discussed