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Preventing unplanned extubations: A test bench simulation comparing endotracheal tube securing techniques in acute care settings
No full textInternational audienceBackground: Effective securing of the endotracheal tube (ETT) after inserting is essential to prevent unplanned extubation (UE). This study compared six ETT securing techniques and a no-device control in resisting to simulated UE, assessing performance across different traction speeds (slow and fast) and planes (frontal and sagittal).Method: A mechanically ventilated mannequin was used. Extubation, defined as a sudden loss of airway pressure, was induced using a tensile testing machine. The required force to cause extubation (forceextubation) was recorded. For each combination of securing technique, traction speed and traction plane, five measurements of forceextubation were collected. Techniques included three cord-based, two elastic adhesive tape-based, one commercial device (AnchorFast™, Hollister), and a control with no securing method.Results: In the sagittal plane, AnchorFast™ required significantly higher forceextubation (median 75 N [IQR: 52-86]) compared to adhesive tape methods (short: 28 N [19-34], p < 0.001; long: 34 N [24-45], p = 0.026). Cord-based techniques performed similarly to the AnchorFast™. The control setup (i.e., without any securing device) and the elastic adhesive tape showed comparable forceextubation levels which were also significantly lower than that of a single cord with a knot. In the frontal plane, forceextubation was higher than in the sagittal plane (115 N [89;148] and 44 N [26;57], respectively, p < 0.001), and no significant differences were observed between techniques.Conclusion: ETT securing techniques using elastic adhesive tape were less effective at preventing simulated UE than either the AnchorFast™ device or a single cord with a knot
Cinématique vs. cinétique : faut-il les dissocier pour optimiser l’apprentissage moteur ?
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Synthesis and characterization of a novel semiconductor hybrid material [(CH3)3N(CH2)3Br]2CuBr4 monocrystal and thin film with high temperature phase transition
No full textInternational audienceOrganic-inorganic copper-bromide materials are attracting tremendous interest because of their great application potential in optoelectronics and photovoltaics. To investigate these potential outcomes, single-crystals of [CH 3 ) 3 N(CH 2 ) 3 Br] 2 CuBr 4 were prepared via the slow evaporation reaction and in form of thin films via the spincoating technique. This material crystalizes at room temperature in the monoclinic symmetrical P2 1 /c space group, with the cell parameters of a = 13.429 (71) Å, b = 8.885 (21) Å, c = 19.806 (3) Å, β = 99.351 (5) °and Z = 4. The crystal structure of [CH 3 ) 3 N(CH 2 ) 3 Br] 2 CuBr 4 was determined to be zero-dimensional (0D). the inorganic [CuBr 4 ] 2-anions are connected to the [Br(CH 2 ) 3 N(CH 3 ) 3 ] + cations with C-H•••Br type hydrogen bond and Br-Br halogen bond. UV-vis spectroscopy on thin film revealed a direct bandgap of 2.12 eV, highlighting the material's potential for optoelectronic applications. Thermal analysis exhibits reversible phase transition at T 1 =361 K and a thermal stability up to 473 K. Temperature-dependent Raman scattering was applied to study the nature of this transition which was related to the weakening of the intermolecular interactions between the organic cations and the inorganic anions and the concomitant strengthening of the intramolecular bindings
A Complex Network Model for Knowledge Graphs’ Relationships
No full textInternational audienceWhen dealing with the structure, content, and quality of knowledge graphs (KGs), most analyses focus on entities, overlooking the significance of relationships and their evolution. In this article, we introduce K nowledge REL ationship M odel (KRELM), a novel and efficient graph model that mimics the behavior of facts accumulation in crowdsourced KGs and accurately simulates the evolution of their structure. By modeling the decentralized process of crowdsourcing, KRELM reproduces key distribution patterns found in relationships, demonstrating that the facts in a KG can be generated incrementally, either by adding new entities or by further describing existing ones. Our theoretical analysis of KRELM reveals that the distribution of facts for relationships follows an exponential law for subjects and a power law for objects, enabling a deeper understanding of knowledge graph dynamics. Experimental validation on major KGs shows that KRELM successfully captures a large part of the structure of real-world relationships, and a longitudinal study of Wikidata confirms its effectiveness in predicting relationship evolution. This work opens new avenues for analyzing and benchmarking KGs
Jouabilité des régimes sonores dans un modèle minimal d’instrument à anche : influence des transitoires d’attaque
No full textComportement des systèmes auto-oscillants et dynamique non linéaire : applications aux instruments de musique et à la voix; GSAM - Acoustique MusicaleNational audienceLes instruments de musique auto-oscillants présentent différents régimes : non oscillants où aucun son n’est produit, périodiques (le plus souvent recherchés) ou non périodiques. Comme dans de nombreux systèmes non linéaires, la coexistence de plusieurs régimes stables pour des valeurs identiques de paramètres est fréquente. Le régime observé dépend alors des conditions initiales des variables d’état. Pour le musicien, cette multistabilité pose la question de la stratégie de contrôle pour accéder au régime recherché. On considère ici un modèle minimal d’instrument à anche simple. Une analyse de bifurcation montre que, sur une large plage de pression buccale du musicien (principal paramètre de contrôle), la solution non oscillante coexiste avec une solution périodique. Le modèle étant de petite dimension, les bassins d’attraction - c.-à-d l’ensemble des conditions initiales menant à chaque régime - sont connus quand la pression buccale est constante. Des simulations temporelles sont réalisées pour étudier l’influence, sur ces bassins (c.-à-d sur le régime établi observé), de transitoires d’attaque de la pression buccale, représentés ici par des rampes saturant à une valeur cible. Ces résultats démontrent que les transitoires des paramètres de contrôle jouent un rôle majeur sur la facilité d’accès aux différents régimes, ce qui suggère qu’ils pourraient être un élément utilisé par les musiciens pour naviguer entre les bassins d’attraction pour atteindre le régime souhaité. Cette étude contribue donc à mieux comprendre l'influence de la dynamique des paramètres de contrôle sur le régime établi des instruments à anche. Une présentation complémentaire réalisée par les auteurs examine cette influence sur les régimes transitoires de ces instruments. D’un point de vue général, ces travaux démontrent que les phénomènes de tipping, où un changement de régime est provoqué par le taux de variation d’un paramètre plutôt que par sa valeur absolue, ont des manifestations concrètes au-delà des sciences du climat où ils sont principalement étudiés
Suivi de la Viscosité des Polymères par Méthode Ultrasonore in situ dans la Chambre du Rhéomètre
No full textEvaluation et contrôle non destructif; GAPSUS - Acoustique Physique, Sous-Marine et Ultra-SonoreNational audienceLa rhéologie joue un rôle fondamental dans la mise en œuvre des polymères. Une compréhension approfondie des propriétés rhéologiques des polymères, durant leur transformation, est nécessaire pour optimiser ces transformations et assurer la qualité des produits finis. L’objectif de ce travail est de développer une méthode ultrasonore, non-destructive, permettant de suivre la viscosité en temps réel des polymères. Dans ce but, une instrumentation adaptée à un rhéomètre est développée. Celle-ci permet des mesures ultrasonores (vitesse) et rhéologiques (viscosité) simultanées. A l’aide d’un transducteur à haute température de 5 MHz en contact sous une plaque en quartz supportant le matériau testé, des mesures synchronisées des signaux acoustiques, de la viscosité et de la température sont effectuées. Une procédure de post-traitement est spécifiquement développée pour estimer le temps de vol du signal se propageant à travers la fine couche de polymère et réfléchie par la plaque métallique supérieure du rhéomètre. Cette procédure propose de s’affranchir des effets de variations de température imposés par le procédé de transformation du polymère. La méthode est validée sur 4 huiles silicone de viscosités calibrées différentes. Les résultats de mesure de la vitesse longitudinale des échantillons placés dans le rhéomètre sont comparés ceux obtenus par une méthode classique d’insertion-substitution. Une bonne concordance est obtenue, confirmant la fiabilité de la méthode de mesure in situ. Des mesures simultanées de la vitesse ultrasonore et de la viscosité complexe sont réalisées pendant des étapes de chauffage (160°C à 200°C) et de refroidissement (200°C à 115°C) sur du polyéthylène. Les résultats obtenus confirment la possibilité de suivre la viscosité du polymère par la mesure de la vitesse longitudinale en fonction de la température et d’identifier le point de solidification du polymère. Cette étude ouvre de nouvelles perspectives pour le suivi de la viscosité des polymères pendant les process industriels
The effort hypothesis at the heart of the virtuous circle
No full textInternational audienceThis article updates the "virtuous circle" model, which links physical exercise with cognition. This model, which originally focused on connectivity between the salience network (SN) and central executive network (CEN), now also incorporates the default mode network (DMN). It describes a bidirectional dynamic: exercise enhances executive functions (i.e., inhibition, flexibility, updating, planning, and problem-solving), which in turn strengthen long-term exercise adherence. This virtuous circle leads to cognitive, physiological, and motivational benefits through synergistic mechanisms induced by exercise such as the effort hypothesis (effort as an investment), the neurotrophic hypothesis, the cardiovascular hypothesis, the inflammatory hypothesis and the glucocorticoid hypothesis. These mechanisms improve connectivity within large-scale neuronal networks, thereby consolidating behavioral regulation. Compared with other behavior change models (e.g., regulation, dual-process, stage-based, and integrative models), the virtuous circle model is notable in light of its circular nature and emphasis on sustainability. In this theoretical framework, adherence to exercise is defined as an evolving strength of the attitudebehavior link, which is shaped by three interconnected processes: immediate motivation (pleasure, mood improvement, social interaction, and rewards), which initiates engagement; sustained effort, which enhances executive control, reduces perceived costs, and fosters habit formation; and behavior-driven attitude change, through cognitive dissonance and effort justification, which aligns beliefs with actions. Recent longitudinal studies have supported the reciprocal associations among exercise, cognition, and brain health, although further trials are needed. This model highlights the fact that early adoption of the virtuous circle promotes the development of health-protective habits, thereby slowing both physical and cognitive aging. In contrast, sedentary lifestyles foster a vicious circle that accelerates decline
« "Concertare" nella Francia del Settecento: l’accademismo musicale come ideale artistico »
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The Impact of Nonlinear Distortion on the Perceived Brightness and Roughness of Electric Guitar Chords
No full textInternational audienceWhen it comes to qualify the nature of audio effects, such as nonlinear distortion, it is not uncommon to observe artists or audio engineers using semantic descriptors such as “warmth”, “smooth”, “rough” or “bright”, to give a specific indication on the timbre itself, altered by those effects. One of the many ways of modifying sound is the nonlinear distortion synthesis technique, also called waveshaping. While a lot of different hardware implementations of distortion effects have their own specificities, each is designed to generate new partials thanks to a nonlinear function. On the other side, it is unclear to which distortion parameter(s) "roughness" and "brightness" refer to, and we don't know yet if those characteristics have a close relation to nonlinear distortion. In this study, we investigate the effect of the nonlinear distortion induced by a guitar pedal, the Boss DS-1, on the perceived brightness and roughness. First, an acoustic analysis reveals how the various controls of the guitar pedal affect the brightness and the roughness of a guitar chord. Then, a listening test confirmed that perceived evolutions of brightness and roughness are coherent with their related presets related to them
A single domain intrabody as a novel tool to bias the subcellular trafficking of the follicle-stimulating hormone receptor
No full textIntracellular variable fragments from heavy-chain only antibodies of camelids (intra-VHH) have been successfully used for their stabilizing properties to solve the 3D structure of active G protein-coupled receptors (GPCRs) bound to their cognate transducers. They also provide tools to link a given conformation of a GPCR to the signalling network engaged, thus allowing extensive structure/activity studies. Recently, they have been instrumental in tracking active GPCRs in various subcellular compartments. Here, we report the isolation and characterization of iPRC2, an intra-VHH recognizing the 1st and 3rd intracellular loops of the FSHR, but not of the luteinizing hormone/choriogonadotropin receptor close relative. Its expression in the cell decreases the cAMP production in response to hormone binding, and requires Gαs for optimal interaction with the receptor. Importantly, iPRC2 increases the FSHR accumulation in the early endosomes, and consequently, diminishes its recycling to the cell surface. Hence, in contrast to previously described intra-VHH that disclose active GPCR intracellular location, iPRC2 provokes per se a location bias, through its ability to reroute the FSHR. Thus, it is an innovative tool to examine the functional consequences of GPCR accumulation in various sub-cellular compartments