Approche instrumentale de l'activité d'enseignement en sciences et techniques des agroéquipements : le cas d'une formation professionnelle agricole

This University thesis looks into the work done by teachers in Agri-Sciences and Techniques: how a "sound agricultural practice" is transmitted in a vocational teaching situation. Its aim is to grasp the organisation of the teaching activity in a particularly discretionary context and in various fluctuating situations. The conceptual framework used for this research is at the intersection of Professional Teaching Practice and an extended instrumental approach. The analytical work is based on tangible teaching practices as they were expressed, and takes into account the symbolic dimension of the device used by the teacher. As it bears on one technical element, the observation of the teachers’ activity makes it possible to highlight the various ways they make use of the chosen devices. The results analysis is based on the concept of invariance (both of the subject and the situation), as it was expected from the teacher’s range of devices and also dialectic relation between the concepts of "empowerment" and "self-accomplishment". The variations can be explained by the active process of the person’s identity construction, proceeding from the feeling of personal sense, a feeling each time unique and incessantly renewed: the teacher’s knowledge and cognition, as it is mustered through the devices used, appear to be closely linked to a form of "re-cognition", leading to varied teaching styles. From a more general point of view, the results verify the model of a "teaching person", as it was propositioned in the theoretical framework; it gives the global teaching act a broader meaning that reaches beyond language.Cette thèse s’intéresse au travail enseignant en Sciences et Techniques des Agroéquipements (STA) dans le cadre de la transmission d’une « bonne pratique agricole » en situation d’enseignement professionnel. Elle vise à saisir l’organisation de l’activité d’enseignement, instrumentée dans un contexte particulièrement discrétionnaire et dans des environnements dynamiques multiples. Le cadre conceptuel mobilisé est au croisement de la didactique professionnelle et de l’approche instrumentale étendue. L’analyse porte à la fois sur des pratiques effectives et racontées et tient compte de la dimension symbolique de l’instrument dans la stratégie didactique mobilisée par l’enseignant. L’observation de l’activité didactique des enseignants, portant sur un même objet technique, permet de mettre en évidence les différents modes d’appropriations des instruments. L’analyse des résultats s’appuie sur la notion d’invariant (du sujet et de la situation) qui est envisagée au niveau du système d’instruments de l’enseignant et dans une articulation dialectique entre « pouvoir d’agir » et « accomplissement de soi ». La variabilité interindividuelle s’explique dans un processus dynamique de construction identitaire du sujet à l’origine « d’un sens pour soi » à chaque fois unique et sans cesse renouvelé : les connaissances en acte mobilisées par l’enseignant au travers de ses instruments apparaissent intimement liées à une forme de « re-connaissance en acte » donnant des styles d’enseignement variés. D’un point de vue plus général, les résultats valident le modèle « du sujet enseignant » proposé dans le cadre théorique en donnant à l’acte global d’enseignement une signification plus large et au-delà du langage

L'orchestration d'un système d'instruments : outils pour l'analyse de l'activité d'enseignants

Cette communication vise à apporter des réflexions méthodologiques sur l’analyse de l’activité d’enseignants. Il s’agit, en s’inspirant de l’approche instrumentale étendue proposée par Rabardel (1999) de montrer comment le système d’instruments convoqués par certains enseignants de Sciences et techniques au travers la mise en œuvre d’une orchestration instrumentale permet de saisir l’organisation de l’activité enseignante. Pour ce faire, nous proposons, à la suite de Trouche (2009), Bourmaud (2006), Munoz et Bourmaud (2012) un outil méthodologique que nous avons adapté et expérimenté dans le cas de l’observation de l’activité d’enseignants en Sciences et Techniques des Agroéquipements. Dans ce contexte, l’orchestration d’un système d’instruments permet, selon nous, non seulement un découpage de l’activité mais également de situer les pratiques individuelles afin de les comparer les unes aux autres

Optimal Predictive Eco-Driving Cycles for Conventional, Electric, and Hybrid Electric Cars

International audienceIn this paper, the computation of eco-driving cycles for electric, conventional and hybrid vehicles using receding horizon and optimal control is studied. The problem is formulated as consecutive-optimization problems aiming at minimizing the vehicle energy consumption under traffic and speed constraints. The impact of the look-ahead distance and the optimization frequency on the optimal speed computation is studied to find a trade-off between the optimality and the computation time of the algorithm. For the three architectures considered, simulation results show that in urban driving conditions, a look-ahead distance of 300m to 500m leads to a sub-optimality less than 1% in the energy consumption compared to the global solution. For highway driving conditions, a look-ahead distance of 1km to 1.5km leads to a sub-optimality less than 2% compared to the global solution

Pasarela en Le Havre Francia

The longitudinal profile of this is a cubic parabola with a 6 m rise and a length of 105 m. Essentially this footbridge consists of a metal pier —that supports two unequal spans— situated at 3/10 of the length so as to utilize the pier of an old bridge; it has the shape of a capital A, the posts of which are pyramids with triangular section and which are formed by sheet plates joined together by welding. The spans, however, consist of: two lateral metal welded beams; a series of bridge ties also of metal, at a distance of 2.50 m from each other and joined to the beams by means of bolts; and resting upon these, a 10 cm thick reinforced concrete slab, protected by a greatly adhesive covering due to the strong slope of the accesses. The suspended solution does not allow any greater thickness of the footbridge and thus the views of the harbour are hardly obstructed. Its assymmetric shape along with the slender form of the pier contributes to making its location in the centre of the city very suitable.El perfil longitudinal de esta pasarela es el de una parábola cúbica con 6 m de flecha y 105 m de longitud. Esencialmente está constituida por una pila metálica —que soporta dos tramos desiguales— situada a 3/10 de la longitud con el fin de reutilizar, para su cimentación, la pila de un antiguo puente; tiene la forma de una gran A, cuyos montantes son pirámides de sección triangular formados por palastros soldados entre sí. Los tramos, a su vez, están formados por: dos vigas laterales metálicas, soldadas; una serie de traviesas, también metálicas, distanciadas 2,50 m y unidas a las vigas mediante bulones; y, apoyando sobre estas últimas, una losa de hormigón armado de 10 cm de espesor, protegida por un revestimiento de gran adherencia motivado por la fuerte pendiente de los accesos. La solución suspendida ha permitido dar un espesor muy pequeño a la pasarela, con lo que apenas se obstaculizan las perspectivas de la dársena. Su forma asimétrica, unida a la gran esbeltez de la pila, la hacen muy adecuada a su emplazamiento en pleno centro de la ciudad

Chemical tuning of Coulomb blockade at room-temperature in ultra-small platinum nanoparticle self-assemblies

This work describes self-assemblies of ultra-small platinum nanoparticles, the electrical properties of which can be adjusted through slight modifications of the assemblies' constituents. Elaborating such systems, stable in air for months, is a first step towards nanoelectronic systems, where the charging energy of the nanoparticles is tuned by the nature of the ligands

Feeding Cyprinus carpio with infectious materials mediates cyprinid herpesvirus 3 entry through infection of pharyngeal periodontal mucosa

Cyprinid herpesvirus 3 (CyHV-3), also known as Koi herpesvirus, is the etiological agent of a mortal disease in common and koi carp. Recently, we investigated the entry of CyHV-3 in carp using bioluminescence imaging and a CyHV-3 recombinant strain expressing luciferase (LUC). We demonstrated that the skin is the major portal of entry after inoculation of carp by immersion in water containing CyHV-3. While this model of infection mimics some natural conditions in which infection takes place, other epidemiological conditions could favour entry of virus through the digestive tract. Here, we investigated whether ingestion of infectious materials mediates CyHV-3 entry through the digestive tract. Carp were fed with materials contaminated with the CyHV-3 LUC recombinant (oral contamination) or immersed in water containing the virus (contamination by immersion). Bioluminescence imaging analyses performed at different times post-infection led to the following observations: (i) the pharyngeal periodontal mucosa is the major portal of entry after oral contamination, while the skin is the major portal of entry after contamination by immersion. (ii) Both modes of inoculation led to the spreading of the infection to the various organs tested. However, the timing and the sequence in which some of the organs turned positive were different between the two modes of inoculation. Finally, we compared the disease induced by the two inoculation modes. They led to comparable clinical signs and mortality rate. The results of the present study suggest that, based on epidemiological conditions, CyHV-3 can enter carp either by skin or periodontal pharyngeal mucosal infection

Determinants of COVID-19 vaccine intention in a University population: a serial mediation approach

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In Utero Exposure to Persistent Organic Pollutants and Childhood Lipid Levels

Animal studies have shown that developmental exposures to polybrominated diphenyl ethers (PBDE) permanently affect blood/liver balance of lipids. No human study has evaluated associations between in utero exposures to persistent organic pollutants (POPs) and later life lipid metabolism. In this pilot, maternal plasma levels of PBDEs (BDE-47, BDE-99, BDE-100, and BDE-153) and polychlorinated biphenyls (PCB-138, PCB-153, and PCB-180) were determined at delivery in participants of GESTation and Environment (GESTE) cohort. Total cholesterol (TCh), triglycerides (TG), low- and high-density lipoproteins (LDL-C and HDL-C), total lipids (TL), and PBDEs were determined in serum of 147 children at ages 6–7. General linear regression was used to estimate the relationship between maternal POPs and child lipid levels with adjustment for potential confounders, and adjustment for childhood POPs. In utero BDE-99 was associated with lower childhood levels of TG (p = 0.003), and non-significantly with HDL-C (p = 0.06) and TL (p = 0.07). Maternal PCB-138 was associated with lower childhood levels of TG (p = 0.04), LDL-C (p = 0.04), and TL (p = 0.02). Our data indicate that in utero exposures to POPs may be associated with long lasting decrease in circulating lipids in children, suggesting increased lipid accumulation in the liver, a mechanism involved in NAFLD development, consistent with previously reported animal data