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"Faire équipe" dans les établissements scolaires publics innovants de la FÉSPI. Appareil psychique d’équipe et complexe de Thésée
No full textThis research focuses on educational teams in innovative French state schools. A socio-historical analysis shows the progressive networking of these twenty schools. The creation of the federation in 2006 (FÉSPI) is conceived as the result of an institutionalisation process, in the context of the fight against the school dropout. A multi-referential and institutional analysis of these dynamics reveals a common structure that drives various collectives. The psychoanalytically oriented clinical approach used for analysing teamwork in the five observed schools sheds light on these group dynamics. In this framework, working with and on bonds—which I consider a ‘clinic of bonding’—allows the hypothesis of a ‘Fespian team psychic apparatus’ to be put forward. The latter is characterised by a bond between teachers and pupils shaped by the myth of adulthood and also by a collegial and parity-based functioning, marked by tensions around the exercise of power. A ‘knotting’ appears between the different forms of expression of the exercise of power—rational, conscious, imaginary, unconscious. The ‘Theseus complex’ unifies what appears to be playing out on various stages—social, institutional, organisational, group, relational and subjective. In these types of schools, the ‘team-building’ consists of putting to work what is at stake in their mode of governance and intersubjective relations, especially the ‘unconscious organizers’ that underlie these educational and professional relationships.Cette recherche porte sur le travail en équipe dans des établissements scolaires publics innovants français. Une analyse socio-historique montre la constitution et l’institutionnalisation du réseau auquel participe une vingtaine d’équipes, jusqu’à la création officielle d’une fédération (FÉSPI) en 2006, dans le contexte de la lutte contre le décrochage scolaire. Une analyse multiréférentielle et institutionnelle des dynamiques à l’œuvre dégage une structure commune animant les différents collectifs fespiens. L’approche clinique d’orientation psychanalytique mobilisée pour analyser le travail des cinq équipes observées se focalise plus particulièrement sur les dynamiques groupales à l’œuvre. Dans ce cadre, j’élabore une « clinique de la reliance » consistant à travailler avec et sur les liens. Cela me permet d’avancer l’hypothèse d’un appareil psychique d’équipe fespien caractérisé, d’une part, par un lien entre enseignants et élèves sous-tendu par le mythe de l’adultité et, d’autre part, par un fonctionnement collégial et paritaire, marqué par des tensions autour d’enjeux de pouvoir. C’est dans ce nouage des différentes formes d’expressions de l’exercice du pouvoir – rationnelle, consciente, imaginaire, inconsciente – que se loge le « complexe de Thésée ». Il permet d’unifier ce qui semble se jouer sur différentes scènes – sociale, institutionnelle, organisationnelle, groupale, relationnelle et subjective. « Faire équipe » dans ces établissements consisterait alors à mettre au travail ce qui est en jeu dans leur mode de gouvernance et dans les liens intersubjectifs, notamment les organisateurs inconscients qui sous-tendent les relations éducatives et professionnelles
Auto-fluorescent phytoliths: can we detect past fires in tropical and subtropical contexts?
No full textInternational audienceTo understand human practices and landscape evolution it is crucial to be able to trace evidence of past fires, notably in tropical environments. In such anthromes, phytoliths are generally well preserved and provide local signals on the environment. However, the different approaches to identifying burnt or heated phytoliths have proved inadequate. The recent investigation of auto-fluorescent phytoliths as proxy indicators of fire opens up new possibilities, however such studies have so far been limited to European temperate regions. The present contribution further explores the potential of this technique, attempting to reconstruct fire histories in tropical and subtropical latitudes. Therefore, we investigated various modern and ancient contexts in Guatemala, Senegal and the Canary Islands using descriptive and quantitative approaches to fluorescence. This comparative process revealed a diversity of fluorescence responses depending on the ecosystems studied, with anthropized areas often producing more fluorescent phytoliths. These results were obtained despite the use of different extraction and mounting methods. In contrast, coloured phytoliths, often considered an indicator of environmental burning, proved not very informative in some of the samples. This study reinforces our conviction that the auto-fluorescence of phytoliths is a universal phenomenon and is useful as a new proxy for detecting ancient fire in tropical and subtropical archaeological and palaeoenvironmental deposits
Ce que la prise en charge des « erreurs » des élèves par les enseignants dit de leurs pratiques
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Laboratory Measurement of CHOH Transitions in the Frequency Range from 216 to 264 GHz for Astronomical Application
No full textInternational audienceMethanol is one of the most abundant complex organic molecules in interstellar environments. Molecular lines of its rare isotopologues 12CHOH and 12CHOH therefore play a crucial role in examining the column density of 12CHOH, which serves as a reference for organic molecular chemistry in interstellar clouds. In this study, we have recorded the spectroscopic emission spectrum of 12CHOH in the frequency range between 216 and 264 GHz by making use of an emission-type millimeter and submillimeter spectrometer. We have specifically paid attention to the Q -branch transitions, which are the strongest line series in this frequency region. Among the stable oxygen isotopes, 16O, 13O, and 18O of methanol, only 12CHOH obviously shows line profiles having double and/or triple peaks in low- J transitions, due to the nuclear quadrupole interaction. The newly obtained 12CHOH data will play an important role in facilitating a deeper understanding of the organic chemistry related to star and planet formation. The 12CHOH line data allow us to trace and constrain the isotopic ratio 17O/18O in methanol, which is efficient to investigate the galactic-scale evolution of elements. In addition, we also assigned some transitions of 13CHOH in the recorded spectrum
Polyoxometalate-derived porphyrins as promising visible light photo-initiating systems for antibacterial applications
No full textInternational audienceTwo hybrid photosensitizers composed of a porphyrin unit covalently linked to one (POM1) or two (POM2) [Mo6O19]2− polyoxometalates (POMs) have been synthesized. These compounds exhibit strong absorption in the visible range and were fully characterized via NMR, ESI-MS and UV–vis spectroscopy, fluorescence, electrochemistry, and DFT calculations. Their efficiency as photosensitizers for the free-radical polymerization (FRP) of acrylated soybean oil (SOA) was evaluated in combination with co-initiators (iodonium salt (Iod) and/or N-methyldiethanolamine (MDEA)). Despite the low fluorescence and triplet quantum yields of POM1 and POM2 (Φfluo (POM1) = 0.007, Φfluo (POM2) = 0.004, ΦT (POM1) = 0.23, ΦT (POM2) = 0.19), we demonstrate that photopolymerization occurs via photoinduced electron transfer reaction and H-abstraction process. Kinetic studies by RT-FTIR confirmed excellent reactivity under LED@405 and 455 nm irradiations, with final acrylate conversions (FCs) reaching up to 98 % in laminate. Notably, FCs of SOA with the three-components systems POM1/Iod/MDEA and POM2/Iod/MDEA reach 93 % and 98 % respectively under LED@405 nm, and 85 % and 86 % under LED@455 nm. EPR spin trapping and laser flash photolysis experiments revealed the formation of phenyl and aminoalkyl radicals, supporting a photo-oxidative initiation mechanism. The resulting materials displayed improved mechanical performance and thermal stability. Also, and due to efficient singlet oxygen (1O2) production under visible light, both POM-based materials highlighted full photobactericidal activity against Staphylococcus aureus, demonstrating thus their potential in light-activated antibacterial coatings
Strong Convergence of Multiplicative Brownian Motions on the General Linear Group
No full textWe consider the family of multiplicative Brownian motions on the general linear group introduced by Driver-Hall-Kemp. They are parametrized by the real variance and the complex covariance of the underlying elliptic Brownian motion. We show the almost sure strong convergence of the finite-dimensional marginals of to the corresponding free multiplicative Brownian motion introduced by Hall-Ho: as the dimension tends to infinity, not only does the noncommutative distribution converge almost surely, but the operator norm does as well. This result generalizes the work of Collins-Dahlqvist-Kemp for the special case which corresponds to the Brownian motion on the unitary group. Actually, this strong convergence remains valid when the family of multiplicative Brownian motions is considered alongside a family of strongly converging deterministic matrices
Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography and for Heart Failure With Preserved Ejection Fraction Diagnosis: An Update From the American Society of Echocardiography
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A remote input of African dust to Last Glacial Europe
No full textInternational audienceDuring the Last Glacial Maximum global surface air temperatures were up to 6 °C lower than preindustrial levels and the mineral dust cycle was highly active, with global dust loading two to four times higher than during the Holocene. Loess deposits and Greenland ice cores show peak dust concentrations during this time. While Asian sources were traditionally seen as the main contributors to dust transported to Greenland, recent studies using geochemical methods suggest a mix of Asian, North African, and European sources. Europe experienced intense dust activity, with mineral particles largely emitted from regional sources. Here we present the trace elements, and strontium and lead isotopes from Last-Glacial Maximum samples collected at 15 sites across Europe. The results reveal that fine dust originated from remote sources, potentially northern Africa. Earth System model simulations support this finding, highlighting Northern Africa's substantial role in dust deposition during glacial periods across the Northern Hemisphere
Reassessing air pollution exposure: How daily mobility and activities shape individual risk in greater Paris
No full textInternational audienceUnderstanding individual exposure to air pollution is essential for tackling environmental inequalities and informing public policies aimed at reducing disparities. Traditional approaches often focus on residential locations, but exposure is intrinsically linked to daily mobility, activities and socio-economic profiles. This study presents new results based on a dynamic exposure modelling approach that takes these dimensions into account, offering a more realistic assessment of air pollution risk. By integrating high-resolution air quality data with detailed information on individual mobility, activities and socio-economic characteristics, we quantify the exposure of 400,000 individuals in the Île-de-France region. Our approach takes into account all the environments that individuals visit during the day and the time spent in each of them, going beyond static exposure assessments based on residential location. We compare this dynamic model with traditional exposure calculations, revealing significant differences in the spatial distributions of PM10 and NO2 exposure. Our analysis highlights how mobility patterns and daily activities contribute to total exposure, demonstrating that place of residence is only one part of reality. For example, commuting, workplaces and leisure activities play a key role in determining individual exposure levels. The results of our study show that dynamic exposure calculation provides a better understanding of exposure factors and offers a framework for understanding environmental inequalities. By shifting the focus from home-based to person-based exposure, our approach makes it possible to identify levers for action to reduce disparities and support targeted public health action. Our study redefines the way in which we assess the risks associated with air pollution, by highlighting the need to take into account mobility behaviour and individual trajectories
14 N Hyperfine Structure and Low Methyl Torsional Barrier in 3-Picoline: Insights from Microwave Spectroscopy and Quantum Chemistry
No full textInternational audienceThe microwave spectrum of 3-picoline (3-methylpyridine) was investigated using a pulsed molecular jet Fourier transform microwave spectrometer and the newly developed Passage And Resonance In Synergy (PARIS) spectrometer across a frequency range of 2 -26.5 GHz. The presence of a methyl internal rotor introduces torsional splitting, while the nitrogen nucleus of the pyridine ring gives rise to a hyperfine structure. A total 637 hyperfine-resolved rotational transitions were assigned and fitted using the programs XIAM and BELGI-Cs-hyperfine, with the latter achieving measurement accuracy. The assignment was further validated by separately fitting the torsional species, which also reached measurement accuracy. The barrier to internal rotation was determined to be 60.198904(29) cm -1 , consistent with the values observed for the 2-and 4-isomers of picoline, where steric and electrostatic effects influence the barrier height.Quantum chemical calculations guided the spectral assignment, and benchmarking computations indicated that the rotational constants calculated at the MP2/6-31G(d,p) level could be useful as assignment guidance