Publications scientifiques de l'Université de Reims Champagne-Ardenne
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Data from long-term experiments in temperate croplands to evaluate soil organic carbon models
No full textInternational audienceSoil organic carbon (SOC) models need independent evaluation against field measurements, but those latter are rarely publicly available and harmonized. In this study, we collected and shared data from 167 agronomic treatments in 34 agronomic long-term experiments (LTEs) located in temperate croplands, allowing the evaluation of several soil organic C models such as RothC, Century, AMG, MIMICS, ICBM, Millenial, and CTOOL. The dataset includes climate data, soil properties, C inputs from crops (n = 4588 records) and organic amendments, irrigation data, monthly soil cover, as well as SOC stock measurements in the topsoil layer (n = 1328 records). Climate, soil moisture, and soil temperature data were extracted from daily climate databases. Carbon inputs from crops were calculated from observed yields and harvest index, with some harvest index values estimated, combined with crop allometric coefficients from the literature. Descriptions of LTE, agronomic treatments, methodological metadata, and a part of the code, accompanies the dataset. The dataset can be reused to evaluate single SOC models, or to evaluate an ensemble of models
Perturbation-Based Q-Learning for Outpatient Surgery Scheduling
No full textInternational audienceOutpatient surgery centers face significant operational challenges due to fluctuations in patient arrivals, heterogeneous processing durations, and variable resource availability. Traditional optimization approaches struggle to generalize under uncertainty, while machine learning methods often lack robustness when deployment conditions differ from training scenarios.This work addresses bi-objective outpatient surgery scheduling by proposing a perturbation-based Q-learning variant (QLP) that explicitly incorporates operational uncertainties during the training phase. We model the problem as a Markov Decision Process following a three-stage Hybrid Flow Shop (preoperative, intraoperative, and postoperative stages) and jointly minimize makespan and cumulative waiting time.Our key contributions are: (i) formulation of the scheduling problem within a reinforcement learning framework, (ii) development of a robust learning mechanism through controlled stochastic perturbations affecting arrival times, processing durations, and resource availability, and (iii) empirical demonstration of superior performance compared to standard Q-learning.Computational experiments demonstrate that QLP maintains minimal performance variance across all perturbation levels, while standard Q-learning exhibits significant degradation under medium-high perturbations. The results confirm that perturbation-based training enables the agent to develop generalizable and robust scheduling policies capable of handling real-world operational uncertainties in healthcare environments
Gestione del coma in Pronto Soccorso
No full textInternational audienceIl coma è definito come una profonda alterazione dello stato di coscienza, responsabile di un difetto di interazione del paziente con l'ambiente. Ogni medico clinico deve sapere come valutare e condurre le prime cure di un paziente in coma. Di fronte ad ogni coma, la priorità è la stabilizzazione del paziente, seguita dalla valutazione clinica iniziale, compreso l'uso di una scala di classificazione del coma. Alcuni esami complementari sono eseguiti sistematicamente (elettrocardiogramma e laboratorio), mentre altri sono indicati caso per caso (TC, risonanza magnetica, elettroencefalogramma, puntura lombare). La ricerca di un'eziologia reversibile guida l'approccio medico. In questo capitolo, dopo una breve rassegna della fisiopatologia del coma, descriviamo gli elementi della gestione medica da effettuare per massimizzare le possibilità di scoprire un'eziologia reversibile, valutiamo le principali cause reversibili di coma e i loro trattamenti abituali, valutiamo le principali cause reversibili di coma e i loro trattamenti abituali, vediamo quali eziologie sospettare in base all'esame clinico iniziale e agli esami complementari, tracciamo un collegamento tra l'esame neurologico e la localizzazione della lesione a priori e infine illustriamo in dettaglio la Glasgow Coma Scale e il punteggio Full Outline of UnResponsiveness (FOUR)
Thermal analysis of a solar-assisted pyrolysis drop tube reactor with radiation heat transfer
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Le circulus au XXe siècle : résurgences et métamorphoses de l’idéal du recyclage agricole des excreta à l’heure de la Grande accélération (France, années 1930 – années 1980)
No full textInternational audienceFrom its initial formulation as ‘circulus’ in the mid-19th century to the urine and faecal matter recycling projects that emerged at the beginning of the 21st century to address the crossing of planetary boundaries and its local consequences, the concept of agricultural recycling of excreta has spanned the 20th century. While the 20th century saw an exacerbation of the urban-rural rift, and the gradual end of traditional recycling practices in particular, criticism of these trends and their socio-environmental effects continued to rise in step with the crises generated by industrial growth. Although it lost its name, the Circulus utopia was reformulated many times in the century of the Great Acceleration. We find echoes of it among the promoters of biodynamic agriculture in the 1930s and 1940s, among certain socialist planners in the post-World War II era and in the ecologist and anarchist movements of the 1970s. By tracing the evolution of this ideal, this article sketches its history and attempts to bridge the gap between past and present excreta recycling utopias.Entre sa formulation première sous le nom de circulus au milieu du XIXe siècle et les projets de recyclage des urines et des matières fécales qui émergent au début du XXI e siècle pour lutter, entre autres, contre le franchissement des limites planétaires et ses effets locaux, l’idéal du recyclage agricole des excreta a traversé le XXe siècle. Si ce dernier est celui de l’exacerbation de la rupture entre villes et campagnes, et notamment de la fin progressive des pratiques anciennes de recyclage, les critiques contre ces tendances et leurs effets socio-environnementaux n’ont cessé de renaître au diapason des crises générées par la croissance industrielle. Si elle a perdu son nom, l’utopie du circulus a ainsi connu de nombreuses reformulations au siècle de la Grande accélération : on la retrouve chez les promoteurs de l’agriculture biodynamique dans les années 1930 et 1940, chez certains planistes d’obédience socialistes de l’après-Seconde Guerre mondiale et dans les mouvements écologistes et libertaires des années 1970. En en suivant la trajectoire, les échos et les évolutions, cet article dresse une esquisse de généalogie, et tente de faire le pont entre les utopies passées du recyclage des excreta et les projets présents
Introduction à la théorie musicale de Gottfried Weber à travers son Versuch einer geordneten Theorie der Tonsetzkunst (1817-1832)
No full textInternational audienceObwohl in der Musiktheoriegeschichte häufig zitiert, ist das bedeutende theoretische Werk Gottfried Webers (1779–1839), der Versuch einer geordneten Theorie der Tonsetzkunst (1. Aufl. 1817-1821) in Frankreich paradoxerweise relativ unbekannt, wahrscheinlich weil es nie ins Französische übersetzt wurde. Das Hauptziel dieses Artikels ist es daher, dem französischsprachigen Publikum eine allgemeine Einführung in dieses Werk zu bieten. Zunächst wird eine kurze Biografie des Autors vorgestellt, um seinen besonderen Status als nicht-professioneller, eklektischer und autodidaktischer Theoretiker hervorzuheben. Da der Versuch drei Auflagen und mehrere Übersetzungen erfahren hat, wird anschließend die Geschichte des Werks nachgezeichnet. Dabei wird der evolutive Charakter des Werks im Laufe der Auflagen deutlich. Nach einer Charakterisierung von Webers empirischem und induktivem theoretischen Ansatz widmet sich der weitere Teil des Artikels einer Untersuchung der wichtigsten Beiträge seiner Theorie, die sich auf die Forschung konzentriert, die sich an den Prinzipien der Harmonie und Tonalität orientiert, ohne jedoch Fragen wie Metrik oder Phraseologie zu außer Acht zu lassen.The landmark theoretical work by Gottfried Weber (1779-1839), Versuch einer geordneten Theorie der Tonsetzkunt (first ed. 1817-1821), although widely cited in works on the history of musical theory, is paradoxically fairly unknown in France, no doubt because it has never been translated into French. The main purpose of this article is therefore to provide a general introduction to the work for a French-speaking readership. A brief biography of the author is given first, highlighting his distinctive status as a non-professional, eclectic, and self-taught theorist. As the Versuch has had three editions and several translations, the history of the work is traced, highlighting its evolutive nature over the course of its editions. After characterising Weber’s theoretical approach as empirical and inductive, the remainder of the article examines the main contributions of his theory, which focuses on a listening-oriented exploration of the principles of harmony and tonality, while also addressing issues such as meter and phrasing.Bien qu’abondamment cité dans les travaux d’histoire des théories musicales, l’ouvrage théorique majeur de Gottfried Weber (1779-1839), le Versuch einer geordneten Theorie der Tonsetzkunt (1re éd. 1817-1821), est paradoxalement assez peu connu en France, sans doute parce qu’il n’a jamais été traduit en français. Cet article a donc pour principal objectif d’en faire une présentation générale pour un lectorat francophone. Une brève biographie de l’auteur est d’abord proposée afin de mettre en évidence son statut particulier de théoricien non professionnel, éclectique et autodidacte. Le Versuch ayant connu trois éditions et plusieurs traductions, l’histoire de l’ouvrage est ensuite retracée. Elle met en évidence le caractère évolutif de l’ouvrage au fil des éditions. Après une caractérisation de l’approche théorique de Weber, empirique et inductive, la suite de l’article est consacrée à un examen des principaux apports de sa théorie, centrée sur la recherche guidée par l’écoute des principes de l’harmonie et de la tonalité, mais ne négligeant pas des questions comme la métrique ou la phraséologie
Décrypter l’empreinte d’une crise : les organisations du spectacle vivant face à la Covid-19
No full textInternational audienceThe lasting effects of COVID-19 on organizations have recently been documented. However, the underlying modalities of such effects remain under-explored. This article uses imprinting theory to analyze the imprint left by the COVID-19 crisis on organizations and to answer the following question: How has the COVID-19 crisis imprinted organizations? To answer this question, we study two performing arts organizations—a chamber music ensemble and a national opera company—using a combination of semi-structured interviews, participant observation, and secondary data analysis. We reveal two distinct forms of imprint—sedimented and essentialized—emerging through three modalities of imprinting (COVID-19 as repertoire, echo, and impulse) through which the crisis affected the organizations. We contribute to the literature on imprinting theory in three ways: We document the imprint of a crisis, conceptualize a new logic of re-imprinting—by subtraction—and specify how the cognitive and structural imprints interact. Finally, we discuss the managerial implications when dealing with crises.Si les traces laissées par la covid 19 sur les organisations ont récemment été documentées, leurs modalités sous-jacentes restent méconnues. Cet article mobilise la théorie de l’empreinte afin d’examiner les effets durables de la crise et de répondre à la question suivante : comment la crise de la covid 19 a-t-elle imprégné les organisations ? Pour répondre à cette question, nous étudions deux organisations du spectacle vivant français - un ensemble de musique de chambre et un opéra national - en combinant entretiens semi-directifs, observation participante et analyse de données secondaires. Nous mettons en lumière deux formes d’empreinte (l’empreinte sédimentée et l’empreinte essentialisée) portées par trois modalités d’empreinte par lesquelles la crise a affecté les organisations (la covid 19 comme répertoire, écho ou impulsion). Ce faisant, l’article contribue à la théorie de l’empreinte de trois manières : il documente l’empreinte d’une crise, conceptualise une nouvelle logique de réimprégnation – par soustraction – et précise comment deux natures d’empreintes (cognitive et structurelle) interagissent. Il offre enfin aux praticiens, du spectacle vivant et au-delà, des clés de compréhension renouvelées pour faire face aux crises à venir
Mechanosensing and Sphingolipid-Docking Mediate Lipopeptide-Induced Immunity in <i>Arabidopsis</i>
No full textBacteria-derived lipopeptides are immunogenic triggers of host defenses in metazoans and plants. Root-associated rhizobacteria produce cyclic lipopeptides that activate systemically induced resistance (IR) against microbial infection in various plants. How these molecules are perceived by plant cells remains elusive. Here, we reveal that immunity activation in Arabidopsis thaliana by the lipopeptide elicitor surfactin is mediated by docking into specific sphingolipid-enriched domains and relies on host membrane deformation and subsequent activation of mechanosensitive ion channels. This mechanism leads to host defense potentiation and resistance to the necrotroph B. cinerea but is distinct from host pattern recognition receptor-mediated immune activation and reminiscent of damage-induced plant immunity. Main TextLipopeptides (LPs) represent a prominent and structurally heterogeneous class of molecules among the broad spectrum of small specialized metabolites synthesized by bacteria. Besides serving key functions for the ecological fitness of the producer (motility, biofilm formation, colonization, nutrient acquisition, or antagonism towards competing neighbors), some LPs also act as triggers of immune responses that restrict pathogen infection of metazoans and plants 1,2 . The vast majority of LPs formed by plant-associated bacteria are comprised of a partly or fully cyclized oligopeptide linked to a single fatty acid chain. Some of these cyclic lipopeptides (CLP) formed by beneficial species belonging to the Pseudomonas and Bacillus genera are potent elicitors of immune responses in the host plant leading to a systemically induced resistance (IR) against infection by microbial pathogens 2,3 .</div
