Musicothérapie et maladie d'Alzheimer: quels sont ses effets sur les symptômes comportementaux et psychologiques de la démence ?

A l’heure actuelle, la population vieillissante, en fulgurante croissance, développe des pathologies chroniques et des démences liées à l’âge. La démence la plus répandue est la maladie d’Alzheimer. Celle-ci s’accompagne de symptômes comportementaux et psychologiques (SCPD) qui engendrent une difficulté dans la prise en charge. Bien souvent, la gestion des manifestations se fait par le biais de médicaments lourds en effets secondaires. La musicothérapie peut être une alternative

Amniotic Epithelial Cells: A New Tool to Combat Aging and Age-Related Diseases?

The number of elderly people is growing at an unprecedented rate and this increase of the aging population is expected to have a direct impact on the incidence of age-related diseases and healthcare-associated costs. Thus, it is imperative that new tools are developed to fight and slow age-related diseases. Regenerative medicine is a promising strategy for the maintenance of health and function late in life; however, stem cell-based therapies face several challenges including rejection and tumor transformation. As an alternative, the placenta offers an extraordinary source of fetal stem cells, including the amniotic epithelial cells (AECs), which retain some of the characteristics of embryonic stem cells, but show low immunogenicity, together with immunomodulatory and anti-inflammatory activities. Because of these characteristics, AECs have been widely utilized in regenerative medicine. This perspective highlights different mechanisms triggered by transplanted AECs that could be potentially useful for anti-aging therapies, which include: Graft and differentiation for tissue regeneration in age-related settings, anti-inflammatory behavior to combat inflammaging, anti-tumor activity, direct lifespan and healthspan extension properties, and possibly rejuvenation in a manner reminiscent of heterochronic parabiosis.Here, we critically discuss benefits and limitation of AECs-based therapies in age-related diseases

Variation in physiological host range in three strains of two species of the entomopathogenic fungus Beauveria

Knowledge of the host range of a biocontrol agent (BCA) is fundamental. Host range determines the BCA's economic potential, as well as the possible risk for non-target organisms. Entomopathogenic fungal strains belonging to the genus Beauveria are widely used as BCA, but our knowledge of their physiological host range is only partial. The aim of this study was to improve our understanding of the physiological host range of three Beauveria strains belonging to two species, B. hoplocheli and B. bassiana. We performed laboratory mortality bioassays to assess their pathogenicity and virulence against nine insect pests, belonging to three orders: Lepidoptera, Coleoptera and Diptera. Mortality rate, mean survival time and mycosis rate were used to estimate virulence. Pathogenicity was assessed as the capacity to cause a disease and induce mortality. Virulence was assessed as the severity of the disease based on mortality rate, mean survival time and mycosis rate. The results of this study revealed significant differences in the physiological host range of the three Beauveria strains tested. The three strains were pathogenic to all Diptera and Lepidoptera species tested. In the case of the Coleoptera, only the B. hoplocheli strain was pathogenic to the white grub Hoplochelus marginalis and only the B. bassiana strains were pathogenic to Alphitobius diaperinus. The B. hoplocheli strain was less virulent on Lepidoptera and Diptera than the two B. bassiana strains. The latter both exhibited very similar virulence patterns. The fact that B. hoplocheli and B. bassiana strains have different host ranges means that they can be used as BCA to target different pests. Impacts on non-target insects across multiple orders cannot be ruled out in the absence of ecological host range studies

Le rôle de l’écrit dans l’apprentissage d’une langue étrangère (L2)

International audienceLa recherche en FLES n’octroie généralement aucune place au rôle de l’écrit dans l’apprentissage de l’oral en L2, reléguant la réflexion à la notion de surdité phonologique (Billières, 2005 ; Dupoux & al., 2002). Or, des études récentes en L1 montrent que les habiletés écrites peuvent modifier la compétence phonologique des sujets (i.e. effet Buben) (Chevrot & al., 2000 ; Soum-Favaro & al., 2014).L’objectif de ce travail est de tester l’existence de cet effet en L2. L’hypothèse est qu’un entrainement écrit améliorera la qualité des représentations phonologiques des apprenants et facilitera l’accès à une production orale normée (Rapp & al., 2002).Pour ce faire, nous analysons un corpus préliminaire d’écrits d’apprenants arabophones de niveau débutant afin d’identifier les phonèmes posant des problèmes de transcription pour bâtir les stimuli expérimentaux du protocole. Il comporte trois phases successives : prétest, test et posttest. Dans la phase de test, les sujets sont répartis en trois groupes : le groupe 1 est entrainé en modalité orale avec la Méthode Verbo-Tonale d’intégration phonétique ; le groupe 2 est entrainé en modalité écrite à travers des tâches de lecture et de copie ; le groupe 3 est un groupe contrôle qui ne suit aucun entrainement. Le matériel expérimental se compose (a) de stimuli sonores comportant les phonèmes à problème identifiés dans le corpus préliminaire pour le groupe 1 (b) des mêmes stimuli transcrits en code écrit pour le groupe 2. Les phases de prétest et de posttest évaluent la conscience phonologique, de façon à mesurer le bénéfice des entrainements des tests.Billières, M. (2005). Les pratiques du verbo-tonal-Retour aux sources. In M. Berré (Ed.), Linguistique de la parole et apprentissage des langues. Questions autour de la méthode verbo-tonale de P. Guberina (pp. 67–87). Mons: CIPA.Chevrot, J.-P. & al. (2000). L’apprentissage des unités phonologiques variables : l’exemple du /R/ post-consonantique final en français. Linx, 42, 89–100.Dupoux, E., & Peperkamp, S. (2002). Fossil markers of language development : phonological « deafnesses » in adult speech processing. In J. Durand & B. Laks (Eds.), Phonetics, Phonology, and Cognition (pp. 168–190). Oxford: Oxford University Press.Rapp, B. & al. (2002). The integration of information across lexical and sublexical processes in spelling. Cognitive Neuropsychology, (19), 1–29.Soum-Favaro, Ch. & al. (2014). La liaison à l’interface entre l’oral et l’écrit. In C. Soum-Favaro, A. Coquillon, & J.-P. Chevrot (Eds.), La liaison : approches contemporaines (pp. 141–167)

Electrical neuroimaging of music processing reveals mid-latency changes with level of musical expertise

This original research focused on the effect of training intensity on cerebral and behavioral processing of complex music using high-density event-related potential (ERP) approaches. Recently we have been able to show progressive changes with training in grey and white matter and higher order brain functioning using (f)MRI ((functional) Magnetic Resonance Imaging), as well as changes in musical and general cognitive functioning. The current study investigated the same population of non-musicians, amateur pianists and expert pianists using spatio-temporal ERP analysis, by means of microstate analysis, and ERP source imaging. The stimuli consisted of complex musical compositions containing three levels of transgression of musical syntax at closure that participants appraised. ERP waveforms, microstates and underlying brain sources revealed gradual differences according to expertise in a 300-500 ms window after the onset of the terminal chords of the pieces. Within this time-window, processing seemed to concern context-based memory updating, indicated by a P3b-like component or microstate for which underlying sources were localized in right middle temporal gyrus, anterior cingulate and right parahippocampal areas. Given that the 3 expertise groups were carefully matched for demographic factors, these results provide evidence of the progressive impact of training on brain and behavior

Creep stability of the proposed AIDA mission target 65803 Didymos: I. Discrete cohesionless granular physics model

As the target of the proposed Asteroid Impact & Deflection Assessment (AIDA) mission, the near-Earth binary asteroid 65803 Didymos represents a special class of binary asteroids, those whose primaries are at risk of rotational disruption. To gain a better understanding of these binary systems and to support the AIDA mission, this paper investigates the creep stability of the Didymos primary by representing it as a cohesionless self-gravitating granular aggregate subject to rotational acceleration. To achieve this goal, a soft-sphere discrete element model (SSDEM) capable of simulating granular systems in quasi-static states is implemented and a quasi-static spin-up procedure is carried out. We devise three critical spin limits for the simulated aggregates to indicate their critical states triggered by reshaping and surface shedding, internal structural deformation, and shear failure, respectively. The failure condition and mode, and shear strength of an aggregate can all be inferred from the three critical spin limits. The effects of arrangement and size distribution of constituent particles, bulk density, spin-up path, and interparticle friction are numerically explored. The results show that the shear strength of a spinning self-gravitating aggregate depends strongly on both its internal configuration and material parameters, while its failure mode and mechanism are mainly affected by its internal configuration. Additionally, this study provides some constraints on the possible physical properties of the Didymos primary based on observational data and proposes a plausible formation mechanism for this binary system. With a bulk density consistent with observational uncertainty and close to the maximum density allowed for the asteroid, the Didymos primary in certain configurations can remain geo-statically stable without including cohesion.Comment: 66 pages, 24 figures, submitted to Icarus on 25/Aug/201

Vaccine nationalism counterintuitively erodes public trust in leaders

Global access to resources like vaccines is key for containing the spread of infectious diseases. However, wealthy countries often pursue nationalistic policies, stockpiling doses rather than redistributing them globally. One possible motivation behind vaccine nationalism is a belief among policymakers that citizens will mistrust leaders who prioritize global needs over domestic protection. In seven experiments (total N = 4,215 adults), we demonstrate that such concerns are misplaced: Nationally representative samples across multiple countries with large vaccine surpluses (Australia, Canada, United Kingdom, and United States) trusted redistributive leaders more than nationalistic leaders—even the more nationalistic participants. This preference generalized across different diseases and manifested in both self-reported and behavioral measures of trust. Professional civil servants, however, had the opposite intuition and predicted higher trust in nationalistic leaders, and a nonexpert sample also failed to predict higher trust in redistributive leaders. We discuss how policymakers’ inaccurate intuitions might originate from overestimating others’ self-interest

Laser-induced plume investigated by finite element modelling and scaling of particle entrainment in laser powder bed fusion

Although metal vaporisation has been observed in several laser processes such as drilling or welding, vapour plume expansion and its induced side effects are not fully understood. Especially, this phenomenon is garnering scientific and industrial interest since recent investigations in laser powder bed fusion (LPBF) have designated metal vaporisation as main source of denudation and powder spattering. The present study aims to provide a new insight on the dynamics of laser-induced vaporisation and to assess the potential of different gases for particle entrainment. A self-consistent finite element model of laser-induced keyhole and plume is thus presented for this purpose, built from a comprehensive literature review. The model is validated with dedicated experimental diagnostics, involving high-speed imaging to measure the ascent velocity of the vapour plume. The transient dynamics of vapour plume is thus quantified for different laser incident intensities and gas flow patterns such as the mushroom-like structure of the vapour plume are analysed. Finally, the model is used as a tool to quantify the entrainment flow expected in LPBF and an analytical model is derived to define a velocity threshold for particle entrainment, expressed in term of background gas properties. Doing so it is possible to predict how denudation evolves when the gaseous atmosphere is changed