Academic literature on the topic 'Suppression des poudres à lever'

AbstractBackgroundThe hallmark characteristics of the murine model of drug addiction include the escalation of cocaine consumption and compulsive punishment-resistant drug seeking. In this study, we evaluated the motivation for drug seeking in cocaine self-administering rats exposed to an escalated dosing regimen that endeavored to mimic the characteristic of escalating drug intake in human addicts. Tropisetron is a 5-HT3 receptor antagonist and α7-nicotinic receptor partial agonist. Utilizing rats trained on the escalated-dosing regimen, we examined the effects of tropisetron on control over compulsive drug-seeking behavior that was defined as footshock-resistant lever pressing.MethodsRats were trained to self-administer cocaine with incremental-infusion doses (from 0.6 to 2.4 mg/kg/infusion) across training sessions (3 h/session) or with a long-access paradigm (i.e., 0.6 mg/kg/infusion, 6 h/d training session). The drug-seeking motivations of 2 groups were estimated by the patterns of drug intake and progressive-ratio schedule. The compulsivity for drug seeking of the group with an escalated dose was further evaluated using the footshock-associated seeking-taking chain task.ResultsThe rats trained on the dose-escalated protocol achieved the same levels of motivated drug seeking as those subjected to a long-access paradigm, as indicated by cocaine intake per training session and breakpoints on a progressive ratio schedule. Tropisetron attenuated compulsive behavior of rats when pressing of the seeking lever potentially led to footshock. Intriguingly, tropisetron did not change the motivation to seek cocaine when footshock was absent. Tropisetron had no effect on locomotor activities or saccharin self-administration.ConclusionsThese results demonstrate that tropisetron restored control over compulsive cocaine seeking, and they indicate that 5-HT3/α7-nicotinic receptors may be potential therapeutic targets for relieving compulsive drug seeking.

Window lifter motor is one of the potential electromagnetic interference (EMI) sources in automobile. Based on the research on the principle of Window lifter motor and the generation mechanism of EMI, its EMI characteristics are tested and analyzed. The EMI suppression methods are proposed. By comparing two filters methods,it shows that the designed filter suppresses the electromagnetic interference more effectively. Its conducted emission and radiated emission are lower than the second lever limits of CISPR 25-2007+.

In order to solve the displacement regression phenomenon of piezoelectric viscous-slip actuators, this paper proposes a lever-type flexible hinge mechanism that uses two sets of piezoelectric stacks to move the slider in both directions and efficiently suppress the displacement regression phenomenon. First, the overall dimensional parameters of the drive are designed, the device is modeled using 3D software, and the driving principle is analyzed. Then a theoretical model is built based on the lever amplification principle to derive the relevant expressions for the piezoelectric viscous slip actuator under sawtooth wave type voltage signals. The piezoelectric stack is simulated and analyzed with COMSOL Multiphysics to obtain the modal and stress-displacement clouds of the flexible hinges. Finally, a prototype was built for experimental testing, and the slider in the device was able to achieve smooth motion and effectively suppress the displacement regression phenomenon. The input voltage of piezo stack A is 100 V, the input voltage of piezo stack D is 150 V, the input frequency is 212 Hz, the maximum output displacement of single-step drive is 46.6 μm, and the amplification ratio of flexible hinge input to output is 2.59. The piezoelectric viscous-slip actuator was verified to be able to achieve effective drive and suppress back-off.

The dorsolateral striatum (DLS) is essential for motor and procedure learning, but the role of DLS spiny projection neurons (SPNs) of direct and indirect pathways, as marked, respectively, by D1 and D2 receptor (D1R and D2R) expression, remains to be clarified. Long-term two-photon calcium imaging of the same neuronal population during mouse learning of a cued lever-pushing task revealed a gradual emergence of distinct D1R and D2R neuronal ensembles that reproducibly fired in a sequential manner, with more D1R and D2R neurons fired during the lever-pushing period and intertrial intervals (ITIs), respectively. This sequential firing pattern was specifically associated with the learned motor behavior, because it changed markedly when the trained mice performed other cued motor tasks. Selective chemogenetic silencing of D1R and D2R neurons impaired the initiation of learned motor action and suppression of erroneous lever pushing during ITIs, respectively. Thus, motor learning involves reorganization of DLS neuronal activity, forming stable D1R and D2R neuronal ensembles that fired sequentially to regulate different aspects of the learned behavior.

This paper presents wind-induced response reduction in a very slender building using smart dampers with proposed bracings-lever mechanism system. The building presents a case study of an engineered design that is instructive. The paper shows that shear response and flexural response of tall buildings present two very different cases for vibration suppression. Smart dampers are implemented optimally in the building to reduce its response in the lateral directions for both structural safety and occupant comfort concerns. New bracings-lever mechanism configurations are proposed for the dampers to improve their performance. The study shows how the proposed configurations can enable application to flexural response and scenarios where the interstory drift is not enough for dampers to work effectively. In addition, a decentralized bang-bang controller improved the performance of the smart dampers.

Control over the media is a key lever of state power. During the First World War and immediate post-war period, British officials in Ireland exercised this power as they attempted to curtail radical Irish nationalism. While state control over the media can be wielded in direct form (usually through suppression), it frequently manifests itself more subtly and indirectly, through moderate censorship for example, especially when the state in question has a democratic dimension and liberal traditions or pretensions. In Ireland in the period covered by this article state interference with the media was both direct and indirect, partially mirroring the dual policy of coercion and conciliation that marked the final years of British governance over the whole island. Neither strategy succeeded in hobbling republican political advance, however, and censorship and suppression came to be regarded by radicals as irritants and obstacles that could be overcome.

Le remplacement des additifs controversés dans les matrices céréalières constitue en enjeu majeur pour répondre aux attentes des consommateurs. Les poudres à lever sont des ingrédients fonctionnels permettant l’obtention de produits biscuitiers alvéolés selon les modes de fabrication industriels. Leur incorporation dans la pâte à biscuits conditionne l’expansion des pâtons lors de l’étape de cuisson. Dans ces travaux, nous avons considéré deux pâtes céréalières avec des taux d’hydratation différents qui déterminent les voies d’incorporation de gaz dans chacune d’elles, avec l’objectif de totalement supprimer les poudres à lever. Dans une pâte à biscuits laminée faiblement hydratée, l’étude a considéré l’utilisation de levures boulangères pour substituer les poudres à lever. La configuration du réseau de gluten module les propriétés élastiques de la pâte et sa capacité à s’étirer pour permettre l’expansion des biscuits à la cuisson. Dans une pâte jaune foisonnée, l’incorporation d’air repose sur la formation d’une mousse stable en même temps que le dégagement gazeux induit par les poudres à lever. L’élimination des poudres à lever, dans cette matrice, a été possible grâce à l’utilisation de protéines végétales fonctionnalisées via différents traitements (physiques ou enzymatiques). Les propriétés interfaciales des protéines de la pâte déterminent leur capacité à stabiliser les bulles d’air qu’elle contient. Celles-ci ont été étudiées par tensiométrie et rhéologie interfaciale. Une approche par plan d’expériences a été implémentée pour optimiser les fonctionnalités et ainsi garantir une alvéolation régulière dans les biscuits
The replacement of controversial additives in cereal matrices represents a major challenge to meet consumers’ expectations. Leavening agents are functional ingredients that are required to obtain porous biscuit products according to industrial manufacturing methods. Their incorporation into biscuit dough determines the expansion of dough pieces during the baking stage. In this work, we considered two cereal doughs with different hydration levels that determine the gas incorporation pathways, aiming to completely suppress the need for leavening agents. In a low-hydration laminated biscuit dough, the study considered the use of baker's yeast as a substitute for leavening agents. The configuration of the gluten network conditions the dough elasticity and its ability to stretch to allow the biscuits to expand during baking. In a sponge drop (whipped) dough, air incorporation relies on the formation of a stable foam simultaneously with the gas release induced by the leavening agents. The removal of leavening agents from this matrix was enabled by using functionalized plant proteins through various treatments (physical or enzymatic). A design of experiments approach was implemented to optimize functionalities and thus, ensure the obtention of biscuits with a uniform crumb structure. During this process, the interfacial properties of the dough proteins determine their ability to stabilize the air bubbles in the matrix. These were studied using tensiometry and interfacial rheology