Periodic bifurcation problems for fully nonlinear neutral functional differential equations via an integral operator approach: the multidimensional degeneration case

We consider a $T$-periodically perturbed autonomous functional differential equation of neutral type. We assume the existence of a $T$-periodic limit cycle $x_0$ for the unperturbed autonomous system. We also assume that the linearized unperturbed equation around the limit cycle has the characteristic multiplier $1$ of geometric multiplicity $1$ and algebraic multiplicity greater than~$1$. The paper deals with the existence of a branch of $T$-periodic solutions emanating from the limit cycle. The problem of finding such a branch is converted into the problem of finding a branch of zeros of a~suitably defined bifurcation equation \hbox{$P(x,\varepsilon) +\varepsilon Q(x, \varepsilon)=0$.} The main task of the paper is to define a novel equivalent integral operator having the property that the $T$-periodic adjoint Floquet solutions of the unperturbed linearized operator correspond to those of the equation $P'(x_0(\theta),0)=0$, $\theta\in[0,T]$. Once this is done it is possible to express the condition for the existence of a branch of zeros for the bifurcation equation in terms of a multidimensional Malkin bifurcation function

Marcel Gauchet, Un monde désenchanté ?

En 1985, Marcel Gauchet publie Le Désenchantement du Monde, un ouvrage qui marque profondément les sciences sociales des religions et suscite un grand nombre de réactions. Un monde désenchanté ? revient, près de vingt ans plus tard, sur les principales thèses de l'auteur en matière de religion. Cet ouvrage est une recueil de textes, articles et conférences, qui ont en commun de naître des interrogations, objections et critiques soulevées à l'occasion de la publication du Désenchantement du Mo..

Marcel Gauchet, Un monde désenchanté ?

En 1985, Marcel Gauchet publie Le Désenchantement du Monde, un ouvrage qui marque profondément les sciences sociales des religions et suscite un grand nombre de réactions. Un monde désenchanté ? revient, près de vingt ans plus tard, sur les principales thèses de l'auteur en matière de religion. Cet ouvrage est une recueil de textes, articles et conférences, qui ont en commun de naître des interrogations, objections et critiques soulevées à l'occasion de la publication du Désenchantement du Mo..

Les Témoins de Jéhovah sur Internet

L’étude de la controverse autour des Témoins de Jéhovah sur le web francophone, rapportée à l’étude dans son ensemble, permet de montrer l’intérêt des recherches sur Internet. Elle révèle l’apparition de nouveaux acteurs et de nouvelles formes de contestation internes ou extérieures à l’organisation jéhoviste. L’anonymat procuré par Internet rend inopérants les moyens de contrôle habituel et l’organisation ne parvient plus à juguler la multiplication des sites personnels et des forums de discussion animés par des témoins de Jéhovah. Un groupe de pression interne à l’organisation apparaît sur le web, ainsi que d’autres associations constituées d’anciens témoins de Jéhovah et qui entrent dans la controverse par le biais de sites web où ils exposent leurs arguments. Internet donne une certaine visibilité à ces nouvelles formes de contestation et complique le travail du chercheur.The study of Jehovah’s Witnesses controversy on the French-speaking Web, compares to the study of the all controversy, legitimates the researches which consider Internet as an interesting object of study. It reveals the appearance of new actors and new shapes of dispute inside and outside Jehovah’s Witnesses’ organization. The anonymity gotten by Internet makes indeed inoperative the usual methods of control and the organization does not manage to suppress the multiplication of Jehovah’s Witnesses’ websites. Internet gives a visibility to these new forms of dispute and complicates the work of researchers.En la intersección entre lo político y lo religioso, el estudio de la controversia alrededor de los Testigos de Jehová en Francia nos permite volver sobre el contexto social en el cual las estrategias de este actor religioso se despliegan. El estudio de esta controversia en la web francófona revela más particularmente la aparición y el crecimiento de grupos de presión internos a la organización de los Testigos. El anonimato proporcionado por Internet vuelve, en efecto, inoperantes a los sistemas de control y de monopolio de la palabra implementados por la jerarquía de los Testigos, como lo testimonia la explosión de sitios « personales » animados por fieles activos de la organización. La generalización del uso de Internet en las sociedades occidentales vuelve igualmente posible para los militantes de las asociaciones de víctimas de las sectas opuestas a los Testigos de Jehová una nueva forma de compromiso « distanciado », que no es menos intenso y que transforma en profundidad el contexto de la controversia. (Trad. de Véronica Béliveau-Giménez

Evaluating the effects of a new syllabus in electricity in grade 8

L'électricité élémentaire est un des domaines où des points de vue consensuels, rejoignant ceux de la recherche en didactique, ont marqué la rédaction des programmes français de 1993. La question est alors de savoir comment la prise en compte, dans les textes officiels, des difficultés rencontrées par les élèves, se traduit dans les acquis des élèves eux-mêmes. Cette étude, réalisée à l'aide de questionnaires papier-crayon, vise à explorer d'éventuels effets d'ensemble et à contribuer à l'élaboration d'un outil pertinent pour ce type d'enquête. Les résultats présentés concernent deux thèmes abordés en classe de quatrième : la conservation de l'intensité du courant dans un circuit série et le générateur, propulseur (en circuit fermé) et non réservoir de charges

Nonlinear Feedback Stabilization of a Rotating Body-Beam Without Damping

This paper deals with nonlinear feedback stabilization problem of a flexible beam clamped at a rigid body and free at the stabilization problem of a flexible beam clamped at a rigid body and free at the other end. We assume that there is no damping. The feedback law proposed hereother end. We assume that there is no damping. The feedback law proposed here consists of a nonlinear control torque applied to the rigid body and either a consists of a nonlinear control torque applied to the rigid body and either a nonlinear boundary control moment or a nonlinear boundary control force or both nonlinear boundary control moment or a nonlinear boundary control force or both of them applied to the free end of the beam. This nonlinear feedback, which insures the exponential decay of the beam vibrations, extends the which insures the exponential decay of the beam vibrations, extends the linear case studied by Laousy et al. to a more general class of controls. This new class of controls is in particular of the interest to be robust

Explicit approximate controllability of the Schr\"odinger equation with a polarizability term

We consider a controlled Schr\"odinger equation with a dipolar and a polarizability term, used when the dipolar approximation is not valid. The control is the amplitude of the external electric field, it acts non linearly on the state. We extend in this infinite dimensional framework previous techniques used by Coron, Grigoriu, Lefter and Turinici for stabilization in finite dimension. We consider a highly oscillating control and prove the semi-global weak $H^2$ stabilization of the averaged system using a Lyapunov function introduced by Nersesyan. Then it is proved that the solutions of the Schr\"odinger equation and of the averaged equation stay close on every finite time horizon provided that the control is oscillating enough. Combining these two results, we get approximate controllability to the ground state for the polarizability system

Exploring Determinants of Interdisciplinary Collaboration within a Geriatric Oncology Setting: A Mixed-Method Study

Therapeutic challenges regarding the population of elderly cancer patients and their heterogeneity lead to the need to implement person-centered approaches in order to optimize care strategies and adapt oncology treatments to each pattern of aging. The International Society of Geriatric Oncology recommends a multidisciplinary evaluation of these patients and the use of screening tools prior to the initiation of treatments. However, previous research shows a poor implementation of these recommendations in geriatric oncology. Although some studies have identified how different perceptions of geriatric oncology might hinder routine teamwork, little is known about the impact of other factors on promoting the collaboration between the two specialties. This mixed-method exploratory study used an online questionnaire to assess the perception of a group of 22 geriatricians and oncology physicians on different determinants of oncology care and teamwork. In this sample, older oncology patients benefited from geriatric care. However, there was a variability regarding age criteria and a limited use of screening tools. The multidimensional framework for interprofessional teamwork by Reeves has been used to analyze some of the determinants of the collaboration between oncology physicians and geriatricians. This study has identified systematic issues to consider when promoting communication and common values between the two disciplines, including available resources in terms of shared time, space and routine actions

Les habitudes des enseignants et les intentions didactiques des nouveaux programmes d'électricité en classe de quatrième

La mise en place de nouveaux programmes nécessite, de la part des enseignants, une prise en compte des intentions des rédacteurs puis une traduction de celles-ci en actes pédagogiques. Nous nous intéressons ici à la perception que les enseignants ont des intentions didactiques contenues dans le nouveau programme d'électricité de la classe de quatrième en France. Des entretiens semi-directifs, conduits avec neuf enseignants, semblent montrer que leur expérience professionnelle, leurs habitudes, limitent leur perception des nouveautés malgré une bonne connaissance des difficultés que les modifications de programme visent à résoudre. Les formes particulières de cet effet de filtrage sont analysées. On observe à ce propos qu'il peut être utile d'associer des intentions didactiques nouvelles à un objet matériel lui-même nouveau qui leur serve de support

Does the practice of mindfulness reduce somatic symptoms and COVID-19-related anxiety? A community-based survey

ObjectiveSince the beginning of COVID-19 pandemic, several studies have shown an increase of psychological distress in the general population. Previous research demonstrated that high levels of anxiety are associated with reporting more somatic symptoms. The ability to adaptively regulate emotions is essential to deal with stressful situations, and it is one of the main components of mindfulness practice. The aim of the present study was to document the effect of mindfulness practice on somatic symptoms and psychological distress in the context of COVID-19 pandemic.MethodsThe study has a descriptive cross-sectional design. During the second wave of COVID-19 pandemic, between November 2020 and January 2021 participants living in France responded to an online survey on the impact of COVID-19 on psychological distress and physical health. The questionnaire included the assessment of COVID-19-related anxiety, mindfulness practice and experience, dispositional mindfulness, somatization, depression, generalized anxiety, and emotion regulation.ResultsA total of 569 people (mean age = 39.8 years, 90% women) were included in the study. COVID-19 related anxiety was associated with higher levels of somatic symptoms, generalized anxiety, and depression. About half of the sample (n = 318, 56%) reported moderate to severe somatic symptoms that were associated with higher levels of depression and anxiety, lower levels of dispositional mindfulness and to the use of maladaptive emotion regulation strategies. Overall, 164 subjects (28.8%) reported practicing meditation. No differences were found in dispositional mindfulness (MAAS score) between beginners and advanced practitioners, regardless of the type, years, frequency, and length of practice. Participants with less experience in mindfulness practice reported a significant higher number of somatic symptoms than non-practitioners and a higher use of rumination. Moreover, mindfulness experience was associated with the use of more adaptive emotion regulation strategies.ConclusionMindfulness meditation has been promoted as a practice enhancing well-being and helping to cope with the psychological impact of stressful events. However, in a distressing situation as COVID-19 pandemic, a limited experience in mindfulness practices might result in the development or endurance of somatic symptoms. Adequate training and a focus on mindful acceptance, may contribute to enhance the effectiveness of mindfulness practice