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Les scripts de carrière pour accompagner les transitions organisationnelles : le cas du groupe familial Sotupa - Tunisie
No full textInternational audienceLe changement organisationnel est un processus de transformation qui affecte les règles formelles ainsi que les comportements individuels et collectifs au sein de l’organisation (Foudriat, 2015). Ce changement exerce une influence significative sur les parcours professionnels, affectant la mobilité interne et les règles régissant les trajectoires de carrières (Glée-Vermande, 2019). Dans ce contexte, le concept de “script de carrière” s’avère particulièrement pertinent pour saisir la co-construction des parcours professionnels. Ce concept place la carrière au centre des relations d’influence réciproques entre l’individu et la structure organisationnelle, offrant ainsi diverses perspectives pertinentes pour l’étude de la gestion des carrières (Barley, 1989 ; Garbe et Cadin, 2015 ; Sidi Ali Cherif et Garbe, 2023b).L’objectif de cette étude est d’analyser et d’interpréter les scripts de carrière des cadres, afin de comprendre comment ces derniers construisent leur parcours au sein du groupe Sotupa qui traverse plusieurs phases de transition organisationnelle. Ce travail fait partie d’un projet doctoral basé sur la démarche de la recherche-intervention (David, 2000). Les résultats, issus de l’analyse de 32 entretiens compréhensif (Kaufmann, 2011), mettent en lumière cinq scripts de carrière illustrant les trajectoires professionnelles des cadres au sein de l’entreprise : script de l’expert, script du manager stratège, script du challenger protéen, script du stabilisateur et script du social humaniste
Modeling breeding programs considering social behavior in large groups of farmed fish
No full textBreeding programs are essential in aquaculture, improving economically and environmentally important traits. In aquaculture systems, animals are raised in large groups, where social interactions are frequent and can influence individual performance. In these circumstances, indirect genetic effects can play an important role in the response to selection, and consequently, their effects on selection outcomes must be analyzed.This study aimed to evaluate the implications of heterogeneous social interaction effects on fish breeding programs using stochastic simulations. We simulated a fish breeding program with 2000 selection candidates from 1000 families formed by a partial mating design of 100 males and 100 females. Social interactions were simulated, affected by the target phenotype and two latent-personality traits. We investigated how genetic gains and phenotypic variances are affected by the magnitude and direction of social interaction effects on the target phenotype, different selection strategies, and the genetic correlations between the target phenotype and personality traits. Our results showed that increased social interaction effects lead to greater phenotypic variability in the target trait. Under mass selection, the genetic means of personality traits change, and these changes depend on the strength and direction of genetic correlations between the focal and personality traits. Conversely, group selection did not increase phenotypic variability but reduced genetic gain for the focal trait compared to mass selection. Moreover, group selection did not alter the genetic means of personality traits. However, this approach increased the rate of inbreeding per generation, which could be mitigated by optimizing the number of families per group..</div
Innover pour cocréer de la valeur avec le client-citoyen : le rôle médiateur des expériences individuelles vécues
No full textThis work explores a central question: how can organizations—public and private—create sustainable, responsible, and legitimate value in contexts of innovation, uncertainty, and profound societal transformation?Rather than opposing qualitative and quantitative approaches, this research work adopts a continuous methodological oscillation inspired by pragmatic research traditions. It pays close attention to lived experiences—those of consumers, users, citizens, and public agents—while simultaneously mobilizing robust modeling techniques and advanced multivariate analyses. The objective is not to reduce complex realities to static indicators, but to understand how perceptions, tensions, and ambivalences shape value-creation processes.The research presented in this volume draws on several emblematic empirical fields, including public innovation, participatory mechanisms, territorial governance, cultural institutions, responsible transition, and organizational innovation. It introduces original conceptual frameworks that articulate public value, use value, and social value, as well as integrative models for analyzing value co-creation between organizations and their stakeholders.Beyond its empirical contributions, this work advances an engaged scientific posture, attentive to the concrete effects of management tools and to the managerial and political implications of innovation. It argues for a management science that actively dialogues with practitioners, informs collective action, and contributes to more responsible, inclusive, and reflexive forms of governance.Cette habilitation à diriger des recherches s’inscrit dans une trajectoire scientifique marquée par une interrogation centrale : comment les organisations, publiques comme privées, peuvent-elles créer une valeur durable, responsable et légitime dans des contextes d’innovation, d’incertitude et de transformations sociétales profondes ?À rebours d’une opposition classique entre approches qualitatives et quantitatives, ce travail revendique une oscillation méthodologique continue, inspirée des méthodes pragmatiques. Attentif aux expériences vécues des individus — consommateurs, usagers, citoyens, agents publics — il mobilise également des outils robustes de modélisation et d’analyse multivariée. L’enjeu n’est pas de réduire la complexité du réel à des indicateurs figés, mais de comprendre comment les perceptions, les tensions et les ambivalences façonnent les processus de création de valeur.Les recherches présentées explorent plusieurs terrains emblématiques : innovation publique, dispositifs participatifs, gouvernance territoriale, institutions culturelles, transition responsable et innovations organisationnelles. Elles proposent des cadres conceptuels originaux articulant valeur publique, valeur d’usage et valeur sociale, ainsi que des modèles intégrateurs permettant d’analyser la co-création de valeur entre organisations et parties prenantes.Au-delà des résultats empiriques, ce manuscrit défend une posture scientifique engagée, attentive aux effets concrets des dispositifs de gestion et aux implications managériales et politiques des innovations étudiées. Il plaide pour des sciences du management capables de dialoguer avec les acteurs, de nourrir l’action collective et de contribuer à une gouvernance plus responsable, plus inclusive et plus réflexive
Decentralized Ranking Aggregation: Gossip Algorithms for Borda and Copeland Consensus
No full textThe concept of ranking aggregation plays a central role in preference analysis, and numerous algorithms for calculating median rankings, often originating in social choice theory, have been documented in the literature, offering theoretical guarantees in a centralized setting, i.e., when all the ranking data to be aggregated can be brought together in a single computing unit. For many technologies (e.g. peer-to-peer networks, IoT, multi-agent systems), extending the ability to calculate consensus rankings with guarantees in a decentralized setting, i.e., when preference data is initially distributed across a communicating network, remains a major methodological challenge. Indeed, in recent years, the literature on decentralized computation has mainly focused on computing or optimizing statistics such as arithmetic means using gossip algorithms. The purpose of this article is precisely to study how to achieve reliable consensus on collective rankings using classical rules (e.g. Borda, Copeland) in a decentralized setting, thereby raising new questions, robustness to corrupted nodes, and scalability through reduced communication costs in particular. The approach proposed and analyzed here relies on random gossip communication, allowing autonomous agents to compute global ranking consensus using only local interactions, without coordination or central authority. We provide rigorous convergence guarantees, including explicit rate bounds, for the Borda and Copeland consensus methods. Beyond these rules, we also provide a decentralized implementation of consensus according to the median rank rule and local Kemenization. Extensive empirical evaluations on various network topologies and real and synthetic ranking datasets demonstrate that our algorithms converge quickly and reliably to the correct ranking aggregation. This work paves the way for principled collective decision-making in fully decentralized systems.</div
Are hydrophilic deep eutectic solvents a potential vehicle for topical delivery of Amphotericin B against cutaneous leishmaniasis? An investigation of physicochemical properties, tolerability and antileishmanial efficacy
No full textInternational audienceDeep eutectic solvents (DES) are homogenous, low-melting mixtures that are liquid at ambient temperature. Recently, DES have attracted interest as novel alternatives to traditional solvents in cutaneous formulations. The aim of this work was to have a better understanding of whether DES could be a safe and effective vehicle for topical delivery of Amphotericin B (AmB) in Cutaneous Leishmaniasis (CL). Based on solubility data, solutions of AmB in DES were prepared and characterized in terms of rheological properties, stability, and aggregation state of AmB by circular dichroism. The tolerability of DES-AmB on the skin was investigated by combining noninvasive techniques with histological assessment; systemic toxicity was also studied. Finally, the best-tolerated formulations were selected for direct assessment of both therapeutic efficacy and toxicity in a murine model of CL. Some of the formulations, especially those based on L-carnitine, could be promising candidates for further development of effective drug formulations against CL, as they were able to show either partial antileishmanial or palliative effects in robust test conditions. However, further optimization is necessary to ensure optimal stability and efficacy of the formulations
Ultramafic float rocks at Jezero crater (Mars): excavation of lower crustal rocks or mantle peridotites by impact cratering?
No full textInternational audienceBased on observation and data from meteorites and in situ scientific missions, experiments as well as models, the Martian mantle is assumed to share some compositional and mineralogical affinity with the terrestrial mantle. However, there might be subtle differences like the Martian mantle being more ferroan. Yet, we do not have any direct analysis of a Martian mantle rock to confirm this assumption. NASA’s Perseverance rover found olivine-rich boulder-sized float rocks on the upper Jezero fan (Mars). These boulders have an ultramafic composition and their mineralogy is dominantly composed of Fo73±3 olivine with high-Mg orthopyroxene, Cr-rich Ti-Fe oxides and minor plagioclase and high-Ca pyroxene. Microtextural and petrological analysis reveals that these minerals crystallized at equilibrium. In addition, these boulders are different from all the bedrocks analyzed by Perseverance along its traverse which are crustal igneous rocks and sediments. Comparing our data to Martian meteorites and available Mars bulk silicate models (BSM), we discuss that these boulders could represent primitive melts and/or lower crustal material, and we specifically hypothesize that they could be mantle peridotites. We propose that these putative mantle rocks could have been excavated by the succession of impacts from the shallow mantle or lower crust in the Isidis region where Jezero crater is located. These olivine-rich boulders could thereby constitute the first direct analysis of a Martian mantle rock
Impact of metallographic polishing on the RF properties of Niobium for SRF applications
No full textInternational audienceThe performance of superconducting radio-frequency (SRF) cavities made of Niobium is tied to the quality of their inner surfaces exposed to the radio frequency (RF) waves. Future superconducting particle accelerators, because of their dimensions or the unprecedented stringent technical requirements, require the development of innovative surface processing techniques to improve processing reliability and if possible ecological footprint and cost, compared to conventional chemical processes. Metallographic polishing (MP) has emerged as a promising polishing technology to address these challenges. Previous studies focused on the characterization of the processed material surface at room temperature in the absence of RF waves. However, the evaluation of material properties, such as surface resistance under RF, at cryogenic temperature has failed, primarily due to the unavailability of devices capable of achieving the necessary resolution in the nanohm range. To overcome this limitation, a quadrupole resonator (QPR) has been utilized. The RF results demonstrate that the MP polishing, developed to preserve a high-quality niobium surface with very low surface resistance, is highly effective compared to conventional polishing. This conclusion is further supported by topography and microstructural analysis of the QPR top-hat samples, which revealed the clear superiority of the metallographic approach
Uniqueness, regularity and characteristic flow for a non strictly convex singular variational problem
No full textInternational audienceThis work addresses the question of uniqueness and regularity of the minimizers of a convex but not strictly convex integral functional with linear growth in a two-dimensional setting. The integrand -- whose precise form derives directly from the theory of perfect plasticity -- behaves quadratically close to the origin and grows linearly once a specific threshold is reached. Thus, in contrast with the only existing literature on uniqueness for functionals with linear growth, that is that which pertains to the generalized least gradient, the integrand is not a norm. We make use of hyperbolic {conservation} laws hidden in the structure of the problem to tackle uniqueness. Our argument strongly relies on the regularity of a vector field -- the Cauchy stress in the terminology of perfect plasticity -- which allows us to define characteristic lines, and then to employ the method of characteristics. Using the detailed structure of the characteristic landscape evidenced in our preliminary study \cite{BF}, we show that this vector field is actually continuous, save for possibly two points. The different behaviors of the energy density at zero and at infinity imply an inequality constraint on the Cauchy stress. Under a {barrier type} convexity assumption on the set where the inequality constraint is saturated, we show that uniqueness holds for pure Dirichlet boundary data devoid of any regularity properties, a stronger result than that of uniqueness for a given trace on the whole boundary since our minimizers can fail to attain the boundary data. We also show a partial regularity result for the minimizer
Exponential degradation of adhesion between visco-hyperelastic materials by isogeometric analysis
No full textInternational audienceVisco-hyperelastic materials are extensively utilized in engineering applications due to their excellent adhesive properties. However, this adhesion gradually weakens when subjected to cyclic bonding–debonding. In this paper, a modified cohesive zone model is developed by introducing an exponential degradation factor that is related to the number of bonding–debonding cycles to characterize the adhesion degradation phenomenon. This model also takes the effect of real contact area on adhesion in each bonding–debonding cycle into account. We then couple this model with the bi-potential contact algorithm to handle interfacial contact during the bonding process, because the cohesive zone model concerns the process of separation. Two-dimensional and three-dimensional numerical implementations of large deformation frictional contact and adhesion are carried out in the context of isogeometric analysis, which offers a geometrically accurate description, a continuous normal field of the contact interface, and precise determination of contact forces. Numerical examples show that the effect of material viscosity on adhesion varies depending on the boundary conditions, and the rough surface has an obvious effect on adhesion