HAL - UPEC / UPEM
Not a member yet
57238 research outputs found
Sort by
Internal dynamics of methyl p -tolyl sulfoxide in the gas phase: Rotational spectroscopy and theoretical studies
No full textInternational audienceA pure rotational spectrum of methyl p-tolyl sulfoxide (MTSO) was studied using chirped-pulse Fourier transform microwave spectroscopy in the frequency range of 18–26 GHz. A single conformer was unambiguously observed in the supersonic jet expansion, which is consistent with the conformational analysis performed using quantum-chemical calculations. Rotational transitions were split into two components of A and E symmetries due to the low-barrier internal rotation of the ring methyl group [ V 3 = 11.0178(23) cm −1 ]. The low energy barrier for the methyl top internal rotation implies an electron-withdrawing effect of the group at the opposite side of the phenyl ring, in comparison with other para-substituted toluenes. The effective ground state ( r 0 ) geometry was derived using the rotational constants from the parent species and the 34 S and eight 13 C singly substituted isotopologues. Compared to two other sulfoxides, methyl phenyl sulfoxide and methyl 4-nitrophenyl sulfoxide, the sulfoxide group in MTSO is slightly more twisted with respect to the plane of the phenyl ring, which could be attributed to the moderate electron-donating effect of the p-methyl group. Furthermore, the pyramidal inversion that interconverts the handedness at the sulfur stereogenic center was explored in the electronic ground (S 0 ) and excited (S 1 ) states with nudged elastic band and time-dependent density functional theory methods. It was found that the pyramidal inversion in S 1 is easier than in S 0 , showing that optical excitation to S 1 will facilitate an effectively barrier-free inversion
Quelle appropriation de la loi par la littérature de jeunesse ?
No full textInternational audienceTraditionally, children's literature presents ordinary family situations, close to the child's experience. It contributes to their education and development by showing a child growing up within a supportive family unit. This reassuring universe is the one desired by society, which has gradually organised the legal conditions defining, first with regard to the father and then jointly with regard to both parents, an authority imbued with rights and duties, the aim of which is the child's interest (art. 371-1 of the Civil Code). From the end of the 19th century onwards, this protection of children was built up through a legal arsenal intended by a 'protective state', calling into question the omnipotence of the father, punishing violence, assaults and attacks on children and increasing the penalties when the perpetrator of the offence is an ascendant. These laws, which aim to ensure the protection of children, including in the family sphere, remind us that the latter can be a place of abuse. We wonder how children's literature deals with this sensitive subject?This paper aims to answer two questions through the study of a body of work aimed at primary school children: What do literary texts say about the law when they talk about sexual violence within the family? How do the works express the law on this traumatic subject without traumatising the young reader?Traditionnellement, la littérature de jeunesse présente des situations familiales ordinaires, proches du vécu du l’enfant. Elle participe alors à son éducation et contribue à son épanouissement en montrant un enfant grandissant au sein d’une cellule familiale qui le soutient. Cet univers rassurant est celui voulu par la société qui a organisé progressivement les conditions juridiques définissant, d’abord à l’égard du père puis conjointement à l’égard des deux parents, une autorité emprunte de droits et de devoirs, ayant pour finalité l’intérêt de l’enfant (art. 371-1 du Code Civil). À partir de la fin du XIXe siècle, cette protection de l’enfance s’est construite à travers un arsenal juridique voulu par un « État protecteur », remettant en cause la toute-puissance paternelle, réprimant les violences, voies de faits et attentats commis contre les enfants et aggravant les sanctions lorsque l’auteur du délit est un ascendant. Ces lois, qui ont pour objectif d’assurer la protection des enfants y compris dans la sphère familiale, rappellent que cette dernière peut être le lieu de maltraitances. Nous nous interrogeons sur la manière dont la littérature de jeunesse porte ce sujet sensible ?Cette communication se propose de répondre à deux questions à travers l’étude d’un corpus d’œuvres destiné aux enfants d’école primaire : Que disent les textes littéraires du droit lorsqu’ils parlent des violences sexuelles à l’intérieur de la famille ? Comment les ouvrages disent-ils le droit sur ce sujet traumatisant sans traumatiser le jeune lecteur
Coexisting structural disorder and robust spin-polarization in half-metallic FeMnVAl
No full text12 pagesInternational audienceHalf-metallic ferromagnets (HMF) are on one of the most promising materials in the field of spintronics due to their unique band structure consisting of one spin sub-band having metallic characteristics along with another sub-band with semiconductor-like behavior. In this work, we report the synthesis of a novel quaternary Heusler alloy FeMnVAl and have studied the structural, magnetic, transport, and electronic properties complemented with first-principles calculations. Among different possible structurally ordered arrangements, the optimal structure is identified by theoretical energy minimization. The corresponding spin-polarized band structure calculations indicates the presence of a half-metallic ferromagnetic ground state. A detailed and careful investigation of the x-ray diffraction data, M\"{o}ssbauer and nuclear magnetic resonance spectra suggest the presence of site-disorder between the Fe and Mn atoms in the stable ordered structure of the system. The magnetic susceptibility measurement clearly establishes a ferromagnetic-like transition below 213 K. The Fe M\"{o}ssbauer spectrometry measurements suggest only the Mn-spins could be responsible for the magnetic order, which is consistent with our theoretical calculation. Surprisingly, the density-functional-theory calculations reveal that the spin-polarization value is almost immunized (92.4\% 90.4\%) from the Mn-Fe structural disorder, even when nonmagnetic Fe and moment carrying Mn sites are entangled inseparably. Robustness of spin polarization and half metallicity in the studied FeMnVAl compound comprising structural disorder is thus quite interesting and could provide a new direction to investigate and understand the exact role of disorders on spin polarization in these class of materials, over the available knowledge
CD8+T cell responsiveness to anti-PD-1 is epigenetically regulated by Suv39h1 in melanomas
No full textInternational audienceTumor-infiltrating CD8 + T cells progressively lose functionality and fail to reject tumors. The underlying mechanism and re-programing induced by checkpoint blockers are incompletely understood. We show here that genetic ablation or pharmacological inhibition of histone lysine methyltransferase Suv39h1 delays tumor growth and potentiates tumor rejection by anti-PD-1. In the absence of Suv39h1, anti-PD-1 induces alternative activation pathways allowing survival and differentiation of IFNγ and Granzyme B producing effector cells that express negative checkpoint molecules, but do not reach final exhaustion. Their transcriptional program correlates with that of melanoma patients responding to immune-checkpoint blockade and identifies the emergence of cytolytic-effector tumor-infiltrating lymphocytes as a biomarker of clinical response. Anti-PD-1 favors chromatin opening in loci linked to T-cell activation, memory and pluripotency, but in the absence of Suv39h1, cells acquire accessibility in cytolytic effector loci. Overall, Suv39h1 inhibition enhances anti-tumor immune responses, alone or combined with anti-PD-1, suggesting that Suv39h1 is an "epigenetic checkpoint" for tumor immunity
Origine des transferts thermiques dans la convection forcée d'un gaz en milieu micro-poreux
No full textInternational audienceUn modèle continu tenant compte de la raréfaction à l'interface gaz/solide est utilisé pour analyser les transferts thermiques dans des écoulements de gaz en milieu micro-poreux. Le gaz subit des variations de température liées uniquement au travail des forces de pression, à la dissipation visqueuse et aux effets de raréfaction : il n'y a pas de chauffage extérieur. Plus de 800 simulations sont effectuées pour les nombres de Reynolds, Mach et Knudsen suivants : Re<100, Ma<1 et Kn<0,1. La moyenne intrinsèque de l’équation de l’énergie sur un VER est établie et les simulations sont utilisées pour évaluer l’importance relative de chaque terme de cette équation. La moyenne intrinsèque du travail de la pression sur un VER est en général le terme dominant qui agit comme un puits de chaleur. En revanche, pour des écoulements faiblement compressibles à basse pression, le gaz peut chauffer sous l’effet de trois sources de chaleur : la dissipation visqueuse, la puissance des contraintes visqueuses à l’interface gaz/solide et la moyenne intrinsèque des fluctuations du terme de convection
La construction d’un collectif scientifique créatif et bienveillant par la mobilisation des émotions et des sens à travers les liens sciences-art : Le Réseau Matières Organiques
No full textInternational audienceCONSTRUCTION OF A CREATIVE AND WELCOMING SCIENTIFIC COLLECTIVE THROUGH THE MOBILIZATION OF EMOTIONS AND SENSES VIA SCIENCE-ART LINKS:The french Organic Matter NetworkCompetition, publication, projects, funding, career: researchers are "squeezed like lem-ons". These pressures can erode their creativity. For the past ten years, the Organic Matter Network has been organizing research schools, with a major part devoted to original creative activities based on the sensorial, artistic or poetic perception of its research themes. We analyze in this article how the approach developed during these research schools, without constraint and following the desires of the group, has contributed to build a creative and friendly research collective. We try to formalize this approach and to evaluate its results.Concurrence, compétition, publication, projets, financement, carrière : les chercheurs sont « pressés comme des citrons ». Ces pressions peuvent briser leur créativité. Le Réseau Matières Organiques organise depuis dix ans des écoles-chercheurs laissant une large part à des ateliers créatifs originaux basés sur la perception sensorielle, artistique ou poétique de ses thématiques de recherches. Nous analysons dans cet article comment la démarche développée au fil de ces écoles, sans contrainte et en suivant les envies du groupe, a permis de construire un collectif de recherche créatif et bienveillant. Nous apportons des éléments de formalisation de cette démarche et tentons d'en évaluer les résultats
CHARLOTT' : quel choix stratégique pour cette PME dynamique ?
No full textCe cas situé en 2018 porte sur l'analyse de la réussite de Charlott'lingerie, entreprise française de vente à domicile de lingerie féminine, créée en 1994 et qui est rapidement devenu une des PME les plus rentables de France. Il invite ensuite les étudiants à réfléchir aux différentes stratégies de développement envisageables pour les années à venir.Le parcours de Christelle Christelle commençait à avoir mal aux pieds dans ses sandales dorées à talon mais le plaisir de tournoyer sur la piste dans une ambiance survoltée compensait largement ce petit désagrément. Quelques instants plus tard, elle retrouvait Frank, son compagnon, pour boire un rafraichissement. Celui-ci était en grande conversation avec Sébastien, lui aussi un « mari », qui profitait de ce séjour tout payé au Maroc grâce au travail de sa femme. Les deux hommes n'en revenaient pas du chemin parcouru par leurs compagnes : il y a 2 ans, Christelle n'avait pas d'emploi et aucune perspective d'en avoir, le moral était au plus bas et la vie de famille s'en ressentait. Sébastien, lui aussi, se souvenait d'« avant » quand les fins de mois finissaient dans le rouge avec ce sentiment d'échec et d'impuissance qui le rongeait, lui et Cindy, en permanence. Aujourd'hui, ils étaient fiers et heureux de voir leurs femmes en robe du soir célébrer leur succès avec leurs collègues dans un cadre si prestigieux
Peripheral centralities in Val d'Europe, east of Paris: the logics of assemblage between Disneyland Paris and New Town principles of planning
No full textInternational audienc
Religion, homosexuality, and the EU: Grasping the beliefs of Romanian Orthodox priests
No full textInternational audienc
Do self‐ratings of the Pittsburgh Sleep Quality Index reflect actigraphy recordings of sleep quality or variability? An exploratory study of bipolar disorders versus healthy controls
No full textInternational audienceSleep disturbances are typical symptoms of acute episodes of bipolar disorder (BD) and differentiate euthymic BD cases from healthy controls (HC). Researchers often employ objective recordings to evaluate sleep patterns, such as actigraphy, whilst clinicians often use subjective ratings, such as the Pittsburgh Sleep Quality Index (PSQI). As evidence suggests the measures may disagree, we decided to compare subjective (PSQI) and objective (3 weeks of actigraphy) sleep profiles in BD cases and HC (n = 154). We examined whether a dimensional approach helps to illustrate different patterns of sleep disturbances and whether the concordance between subjective and objective recordings varies according to clinical status (BD versus HC). Principal component analysis (PCA) extracted two factors from the PSQI, and separate PCAs of actigraphy recordings extracted two factors for mean values of sleep parameters and one factor for intra-individual variability. Correlational and linear regression analyses of PCA-derived dimensions demonstrated that, in both BD and HC, a PSQI "Sleep duration-efficiency" factor was significantly correlated with an actigraphy "Sleep initiation-duration" factor. Furthermore, in BD cases only, the PSQI total score and a PSQI "Sleep Impairments" factor were each significantly correlated with an actigraphy "Sleep Variability" factor. Overall, we found that subjective experiences of sleep may be modulated by different components of objectively recorded sleep in BD compared with HC. Also, the use of PCA enabled us to consider the multi-dimensional nature of subjective sleep, whilst the inclusion of intra-individual sleep variability afforded a more subtle evaluation of objective sleep