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Search for heavy neutral leptons in decays to positrons
No full textInternational audienceA search for heavy neutral lepton () production in in-flight decays using data collected by the NA62 experiment at CERN in 2017-2024 is reported. Upper limits for the extended neutrino mixing matrix element are established at the level of for heavy neutral leptons with mass in the range 95-126 and lifetime exceeding 50 ns
The Next Generation Virgo Cluster Survey (NGVS). XIII. The Luminosity and Mass Function of Galaxies in the Core of the Virgo Cluster and the Contribution from Disrupted Satellites
No full textInternational audienceWe present measurements of the galaxy luminosity and stellar mass function in a 3.71 deg^2 (0.3 Mpc^2) area in the core of the Virgo Cluster, based on \u\^\ast griz data from the Next Generation Virgo Cluster Survey (NGVS). The galaxy sample\mdashwhich consists of 352 objects brighter than M _ g = -9.13 mag, the 50% completeness limit of the survey\mdashreaches 2.2 mag deeper than the widely used Virgo Cluster Catalog and at least 1.2 mag deeper than any sample previously used to measure the luminosity function in Virgo. Using a Bayesian analysis, we find a best-fit faint-end slope of α = -1.33 \plusmn 0.02 for the g-band luminosity function; consistent results are found for the stellar mass function and the luminosity function in the other four NGVS bandpasses. We discuss the implications for the faint-end slope of adding 92 ultracompact dwarfs (UCDs)\mdashpreviously compiled by the NGVS in this region\mdashto the galaxy sample, assuming that UCDs are the stripped remnants of nucleated dwarf galaxies. Under this assumption, the slope of the luminosity function (down to the UCD faint magnitude limit, M _ g = -9.6 mag) increases dramatically, up to α = -1.60 \plusmn 0.06 when correcting for the expected number of disrupted non-nucleated galaxies. We also calculate the total number of UCDs and globular clusters that may have been deposited in the core of Virgo owing to the disruption of satellites, both nucleated and non-nucleated. We estimate that \tilde150 objects with M _ g \lsim -9.6 mag and that are currently classified as globular clusters might, in fact, be the nuclei of disrupted galaxies. We further estimate that as many as 40% of the (mostly blue) globular clusters in the Virgo core might once have belonged to such satellites; these same disrupted satellites might have contributed \tilde40% of the total luminosity in galaxies observed in the core region today. Finally, we use an updated Local Group galaxy catalog to provide a new measurement of the luminosity function of Local Group satellites, α = -1.21 \plusmn 0.05, which is only 1.7σ shallower than measured in the core of the Virgo Cluster. Based on observations obtained with MegaPrime/MegaCam, a joint project of the Canada-France-Hawaii Telescope (CFHT) and CEA/DAPNIA, at the CFHT, which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l\rsquoUnivers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii
Evidence accumulation as a model for lexical selection
No full textInternational audienceWe propose and demonstrate evidence accumulation as a plausible theoretical and/or empirical model for the lexical selection process of lexical retrieval. A number of current psycholinguistic theories consider lexical selection as a process related to selecting a lexical target from a number of alternatives, which each have varying activations (or signal supports), that are largely resultant of an initial stimulus recognition. We thoroughly present a case for how such a process may be theoretically explained by the evidence accumulation paradigm, and we demonstrate how this paradigm can be directly related or combined with conventional psycholinguistic theory and their simulatory instantiations (generally, neural network models). Then with a demonstrative application on a large new real data set, we establish how the empirical evidence accumulation approach is able to provide parameter results that are informative to leading psycholinguistic theory, and that motivate future theoretical development. (C) 2015 Elsevier Inc. All rights reserved
Li3V2(PO4)3 sintering atmosphere optimisation for its integration in all-solid-state batteries
No full textInternational audienceIntegration of active materials into the architecture of all-solid-state batteries represents a significant scientific inquiry. Li3V2(PO4)3 (LVP), a positive and negative electrode active material for Li-ion batteries, has been subject to extensive research to elucidate its electrochemical behaviour during cycling processes. However, the comprehensive analysis of its thermal behaviour under different sintering atmosphere conditions has remained underexplored, particularly in the context of its compatibility with solid electrolytes. This study presents a meticulous study of sintering process under different atmospheres with precise control over oxygen partial pressure. Interestingly, we were able to sinter LVP and obtain dense, pure ceramic phase under slightly oxidising atmosphere, characterized by conductivity properties analogous to those observed in samples sintered under Ar/H2 conditions. The findings of this investigation contribute to the understanding of the optimal conditions required for the sintering of LVP, paving the way for the co-sintering of this material with inorganic solid electrolyte unstable under reducing atmosphere, such as LATP
Test of lepton flavour universality with decays
No full textInternational audienceLepton flavour universality in rare transitions is tested for the first time using meson decays. The measurements are performed using collision data collected by the LHCb experiment between 2011 and 2018, corresponding to a total integrated luminosity of 9. Branching fraction ratios between the and decays are measured in three regions of dilepton mass squared, , with , , and . The results agree with the Standard Model expectation of lepton flavour universality
Lattice QCD calculation of the and meson masses at the physical point using rooted staggered fermions
No full textInternational audienceWe present a lattice calculation of the and meson masses at the physical point and in the continuum limit, based on flavors of rooted staggered quarks. Our analysis includes gauge ensembles at the physical pion and kaon masses spread over six lattice spacings in the range [0.064-0.1315]~fm. Our main results read MeV and MeV, consistent with the experimental values. This is an important numerical test that supports the validity of the fourth root procedure used in the staggered quark formalism. This calculation was the first step towards extracting the pseudoscalar transition form factors of the and mesons that play a crucial role in the hadronic light-by-light contribution to the muon
Modeling the Cosmic Dispersion Measure in the D < 120 Mpc Local Universe
No full textInternational audienceThe Local Universe (D < 120 Mpc) has been intensely studied for decades, with highly complete galaxy redshift surveys now publicly available. These data have driven density reconstructions of the underlying matter density field, as well as constrained simulations that aim to reproduce the observed structures. In this paper, we introduce a dispersion measure (DM) model that makes use of this detailed knowledge of our Local Universe within D < 120 Mpc. The model comprises three key components: (i) the DM from the Milky Way halo and the intra-group medium (up to 3.4 Mpc), derived from the HESTIA simulations, a series of constrained hydrodynamic simulations designed to reproduce our Local Group; (ii) the DM contribution from the large-scale intergalactic medium beyond the Local Group (3.4 Mpc < D < 120 Mpc), calculated using the HAMLET reconstructed matter density field; and (iii) the individual DM contributions from Local Universe galaxy halos and clusters based on data from the 2MASS Galaxy Group Catalog and the NASA/IPAC Extragalactic Database. This comprehensive model will be made available as a Python package. As the most realistic model to date for DM in the local volume, it promises to improve the constraints of DM contributions from the Intergalactic Medium and Circumgalactic Medium of FRBs, thereby enhancing the accuracy of cosmic baryon distribution calculations based on DM analysis of FRBs
Expérimenter le vidéo-montage avec les jeunes en situation de handicap à Mayotte pour construire son identité professionnelle
No full textInternational audienceDit onderzoek onderzoekt hoe het proces van toe-eigening (Rabardel, 1995) van een videobewerkingsapplicatie bijdraagt aan de constructie van de professionele identiteit van middelbare scholieren met een handicap (Agraz, 2017). De methodologie combineert een experiment in het beroepsonderwijs dat wordt uitgevoerd rond videobewerking op een touchpad (analyse van activiteitssporen, directe observatie) en een etnografisch onderzoek in het veld (deelnemende observatie, velddagboek). Het experiment wordt uitgevoerd in een Unité Localisée d'Inclusion Scolaire (ULIS) in Mayotte, met vier jongeren die 2 jaar worden gevolgd. De resultaten onthullen de opkomst van een professionele zelfidentificatie door het gebruik van een filmisch afwisselingsapparaat (opnemen Versus kijken) en een integratie van professionele gebaren. Het onderzoek wijst op een afwisseling in professionele identiteit, tussen afstand en integratie. Tot slot biedt het nieuwe perspectieven op de professionele identiteit van jongeren met een beperking.This study examines how the appropriation process (Rabardel, 1995) of a video editing application contributes to the construction of the professional identity of high school students with disabilities (Agraz, 2017). The methodology combines an experiment in a vocational high school conducted around video editing on a touch tablet (analysis of activity traces, direct observation), and an ethnographic field survey (participant observation, field diary). The experiment was carried out in a Unité Localisée d’Inclusion Scolaire (ULIS) in Mayotte, with four young people monitored over 2 years. The results reveal the emergence of an identification of the professional self through the use of a filmic alternation device (recording Versus viewing) and an incorporation of professional gestures. The research highlights an alternation in professional identity, between distance and incorporation. In conclusion, it offers new perspectives on the professional identity of young people with disabilities.Este estudio examina cómo el proceso de apropiación (Rabardel, 1995) de una aplicación de edición de vídeo contribuye a la construcción de la identidad profesional de los estudiantes de secundaria con discapacidad (Agraz, 2017). La metodología combina una experimentación en la escuela secundaria profesional realizada en torno a la edición de vídeo en tableta táctil (análisis de rastros de actividad, observación directa) y una investigación etnográfica sobre el terreno (observación participante, cuaderno diario de campo). La experimentación se lleva a cabo en una Unidad Localizada de Inclusión Escolar (ULIS) en Mayotte, con cuatro jóvenes seguidos durante 2 años. Los resultados revelan la aparición de una identificación del yo profesional a través del uso de un dispositivo de alternancia fílmica (grabar Versus ver) y una incorporación de gestos profesionales. La investigación pone de manifiesto una alternancia en la identidad profesional, entre la distancia y la incorporación. En conclusión, ofrece nuevas perspectivas sobre la identidad profesional de los jóvenes con discapacidad.Cette étude examine comment le processus d’appropriation (Rabardel, 1995) d’une application de montage vidéo contribue à la construction de l’identité professionnelle des lycéens en situation de handicap (Agraz, 2017). La méthodologie combine une expérimentation en lycée professionnel menée autour du montage vidéo sur tablette tactile (analyse des traces d’activité, observation directe), et d’une enquête ethnographique sur le terrain (observation participante, cahier journal de terrain). L’expérimentation est menée dans une Unité Localisée d’Inclusion Scolaire (ULIS) à Mayotte, auprès de quatre jeunes suivis sur 2 ans. Les résultats révèlent l’émergence d’une identification du soi professionnel à travers l’utilisation d’un dispositif d’alternance filmique (enregistrer Versus visionner) et une incorporation des gestes professionnels. La recherche met en évidence une alternance dans l’identité professionnelle, entre distance et incorporation. En conclusion, elle offre de nouvelles perspectives sur l’identité professionnelle des jeunes en situation de handicap.Questo studio esamina come il processo di appropriazione (Rabardel, 1995) di un'applicazione di montaggio video contribuisce alla costruzione dell'identità professionale degli studenti delle scuole superiori in situazione di disabilità (Agraz, 2017). La metodologia combina una sperimentazione in un liceo professionale condotta attorno al montaggio video su tavoletta tattile (analisi delle tracce di attività, osservazione diretta) e un'indagine etnografica sul campo (osservazione partecipante, quaderno di giornale sul campo). La sperimentazione è condotta in un'Unità Localizzata di Inclusione Scolastica (ULIS) a Mayotte, con quattro giovani seguiti per 2 anni. I risultati rivelano l'emergere di un'identificazione del sé professionale attraverso l'uso di un dispositivo di alternanza cinematografica (registrare Versus visualizzare) e un'incorporazione dei gesti professionali. La ricerca evidenzia un'alternanza nell'identità professionale, tra distanza e incorporazione. In conclusione, offre nuove prospettive sull'identità professionale dei giovani con disabilità
Chromosomal abnormalities in oocyte donor candidates: a French survey of over 8200 karyotypes
No full textInternational audienceObjective: To study karyotypes of more than 8,200 oocyte donor candidates in nulliparous or multiparous women compared to a reference population.Design: A retrospective observational multicentric study.Subjects: The study included two cohorts of oocyte donor candidates recruited between January 2005 and October 2021: multiparous women with at least one child at the time of recruitment, and nulliparous women. Both were compared to a reference population composed of female newborns from literature.Exposure: Not applicable.Main outcome measures: Blood lymphocyte karyotype.Results: A total of 8229 oocyte donor candidates from 22 fertility centers were included in this study. Nulliparous women (n=1890) and multiparous ones (n=6339) were compared to 8102 female newborns. Overall, 65 candidates were carriers of chromosomal abnormalities and were therefore excluded from the donation process (0.79%, 95% CI: 0.60-0.98). The occurrence of balanced structural chromosomal rearrangements was globally increased in the study population (0.49%, 95% CI: 0.34-0.64) compared to female newborns (0.24%, 95% CI: 0.34-0.64, p=0.0086). The number of reciprocal translocations was increased 5-fold in nulliparous oocyte donor candidates (0.37%, 95% CI: 0.10-0.64, p=0.013). The incidence of sex chromosome mosaicism was notably increased in multiparous oocyte donor candidates, with 17 cases (0.27%, 95% CI: 0.14-0.40, p=0.0052). Among chromosomal aberration carriers only two nulliparous women (one reciprocal translocation and one sex chromosome mosaicism) had fertility issues with a diagnosis of premature ovarian failure.Conclusion: In this comprehensive 16-years French experience of karyotyping in oocyte donor candidates, we confirmed an increased incidence of balanced structural chromosomal rearrangements, especially among those without children at the time of recruitment. Karyotyping could be considered to identify any chromosomal abnormalities that may not be easily detectable through medical questioning. These abnormalities pose an inherent genetic risk for gamete recipients if left undetected
Refining Boolean models with the partial most permissive scheme
No full textMotivation: In systems biology, modelling strategies aim to decode how molecular components interact to generate dynamical behaviour. Boolean modelling is more and more used, but the description of the dynamics from two-levels components may be too limited to capture certain dynamical properties. %However, in Boolean models, the description of the dynamics may be too limited to capture certain dynamical properties. Multivalued logical models can overcome this limitation by allowing more than two levels for each component. However, multivaluing a Boolean model is challenging. Results: We present MRBM, a method for efficiently identifying the components of a Boolean model to be multivalued in order to capture specific fixed-point reachabilities in the asynchronous dynamics. To this goal, we defined a new updating scheme locating reachability properties in the most permissive dynamics. MRBM is supported by mathematical demonstrations and illustrated on a toy model and on two models of stem cell differentiation