222 research outputs found
Repenser la musicologie au sein des sciences humaines
À ceux qui traditionnellement mettent en doute la musicologie, proposons une réponse précise : nous musicologues cherchons par tous les moyens à comprendre comment et pourquoi l’homme a toujours et partout estimé si important de créer des formes symboliques à l’aide de formes sonores. (François-Bernard Mâche, « Éclectisme et synthèse. Les conditions d’une nouvelles musicologie générale », 1994) Au seuil de son activité d’enseignement et de direction de recherche à l’EHESS, la conférence « Les..
Une ingénierie éducative innovante pour travailler des compétences en EDD dans le cadre d'un Observatoire Hommes Milieux
International audienceNous présentons un dispositif qui engage des relations entre chercheurs, enseignants et élèves dans un territoire partagé. Un Observatoire Hommes Milieux permet d'appréhender la complexité, l'incertitude, les savoirs en construction et la projection vers le(s) futur(s) possible(s), compétences centrales en éducation au développement durable. Des jeux de rôle ont été proposés à travers la co-construction de séquences pédagogiques par des chercheurs et des enseignants, et des dispositifs pédagogiques variés tels que des sorties, des débats et des rencontres avec des chercheurs et des acteurs du territoire. Les élèves se sont confrontés à une certaine complexité en manipulant des temporalités : observation de co-évolutions hommes-milieux dans le passé et projection dans le futur par exemple. En retour, les acquis de ce travail visaient à développer chez les élèves des capacités à réinvestir hors de l' école ce qu'ils ont vu en classe. C' est un enjeu fort de la contribution des activités scolaires à l' éducation citoyenne
Regards disciplinaires croisés sur les paysages ordinaires de proximité : un enjeu pour enrichir le lien des élèves au territoire où ils habitent
Habiter est une relation entre un individu ou un groupe social et l’espace dans lequel il inscrit ses pratiques quotidiennes. Cet espace correspond à un ensemble de lieux en réseaux qui peut être vu dans sa matérialité, mais aussi dans ses dimensions symboliques qui permettent de lui donner un sens et d’en construire la représentation que chacun s’en fait (Cailly, 2008). Dans ce processus qui associe étroitement réalité visible et dimension idéale, l’apparence du territoire a une importance c..
Gearing Time Toward Musical Creativity: Conceptual Integration and Material Anchoring in Xenakis’ Psappha
Understanding compositional practices is a major goal of musicology and music theory. Compositional practices have been traditionally viewed as disembodied and idiosyncratic. This view makes it hard to integrate musical creativity into our understanding of the general cognitive processes underlying meaning construction. To overcome this unnecessary isolation of musical composition from cognitive science, in this conceptual analysis, we approach compositional processes with the analytic tools of blending theory, material anchoring, and enaction. Our case study is Iannis Xenakis’ use of sieves for distributing rhythmic patterns in Psappha. Though disregarded in previous accounts, the timeline and the gearwheel provide crucial conceptual templates for anchoring Xenakis’ idea of time for this score. This case study of conceptual integration templates for temporal representation seeks to gain insight into musical creativity, embodiment, and blending, especially into how virtual interactions with material structures facilitate the construction of complex meanings
Le jeu de rôle en EDD pour dépasser une pensée binaire : une étude de cas à l’école primaire
Le jeu de rôle est une forme de débat dans lequel les arguments sont fournis aux participants. Cet article repose sur l’analyse des échanges langagiers lors d’un jeu de rôle autour d’une problématique relative au territoire local dans une classe d’élèves français âgés de 8 à 10 ans. Nous identifions les accords et désaccords avec les diverses propositions afin d’établir leur degré de cohérence avec leur personnage. Les résultats témoignent d’un niveau d’argumentation élevé, d’une cohérence dans les arguments avancés ainsi que de l’émergence de nouvelles propositions. Le jeu de rôle semble remplir sa fonction d’appropriation d’arguments. Il rend compte également d’une possible construction de compétences écocitoyennes.Debating is a school practice mobilized in various contexts with varied stakes and renewed modalities in primary school French curriculum. We present the analysis of linguistic exchanges during a role-play with 8 to 10 years old pupils from the point of view of argumentation. We try to identify if pupils are capable of mobilizing arguments and if exchanged arguments are coherent with the character they represent. Results testify of a high argumentation level, of coherence in advanced arguments as well as an emergence of new proposals. If role-play fulfills its arguments appropriation function, it also conveys a possible thought emancipation
CSI 2264: Characterizing Accretion-Burst Dominated Light Curves for Young Stars in NGC 2264
Based on more than four weeks of continuous high cadence photometric
monitoring of several hundred members of the young cluster NGC 2264 with two
space telescopes, NASA's Spitzer and the CNES CoRoT (Convection, Rotation, and
planetary Transits), we provide high quality, multi-wavelength light curves for
young stellar objects (YSOs) whose optical variability is dominated by short
duration flux bursts, which we infer are due to enhanced mass accretion rates.
These light curves show many brief -- several hour to one day -- brightenings
at optical and near-infrared (IR) wavelengths with amplitudes generally in the
range 5-50% of the quiescent value. Typically, a dozen or more of these bursts
occur in a thirty day period. We demonstrate that stars exhibiting this type of
variability have large ultraviolet (UV) excesses and dominate the portion of
the u-g vs. g-r color-color diagram with the largest UV excesses. These stars
also have large Halpha equivalent widths, and either centrally peaked, lumpy
Halpha emission profiles or profiles with blue-shifted absorption dips
associated with disk or stellar winds. Light curves of this type have been
predicted for stars whose accretion is dominated by Rayleigh-Taylor
instabilities at the boundary between their magnetosphere and inner
circumstellar disk, or where magneto-rotational instabilities modulate the
accretion rate from the inner disk. Amongst the stars with the largest UV
excesses or largest Halpha equivalent widths, light curves with this type of
variability greatly outnumber light curves with relatively smooth sinusoidal
variations associated with long-lived hot spots. We provide quantitative
statistics for the average duration and strength of the accretion bursts and
for the fraction of the accretion luminosity associated with these bursts.Comment: Accepted for publication in AJ. 39 pages; 6 tables; 25 figures, many
of which are highly degraded to meet size limits. Please download the regular
resolution version at
http://web.ipac.caltech.edu/staff/amc/staufferetal2014.pd
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Modeling plant transpiration under limited soil water: comparison of different plant and soil hydraulic parameterizations and preliminary implications for their use in land surface models
Accurate estimates of how soil water stress affects plant transpiration are crucial for reliable land surface model (LSM) predictions. Current LSMs generally use a water stress factor, β, dependent on soil moisture content, θ, that ranges linearly between β = 1 for unstressed vegetation and β = 0 when wilting point is reached. This paper explores the feasibility of replacing the current approach with equations that use soil water potential as their independent variable, or with a set of equations that involve hydraulic and chemical signaling, thereby ensuring feedbacks between the entire soil–root–xylem–leaf system. A comparison with the original linear θ-based water stress parameterization, and with its improved curvi-linear version, was conducted. Assessment of model suitability was focused on their ability to simulate the correct (as derived from experimental data) curve shape of relative transpiration versus fraction of transpirable soil water. We used model sensitivity analyses under progressive soil drying conditions, employing two commonly used approaches to calculate water retention and hydraulic conductivity curves. Furthermore, for each of these hydraulic parameterizations we used two different parameter sets, for 3 soil texture types; a total of 12 soil hydraulic permutations. Results showed that the resulting transpiration reduction functions (TRFs) varied considerably among the models. The fact that soil hydraulic conductivity played a major role in the model that involved hydraulic and chemical signaling led to unrealistic values of β, and hence TRF, for many soil hydraulic parameter sets. However, this model is much better equipped to simulate the behavior of different plant species. Based on these findings, we only recommend implementation of this approach into LSMs if great care with choice of soil hydraulic parameters is take
Association between polygenic risk score of Alzheimer's disease and plasma phosphorylated tau in individuals from the Alzheimer's Disease Neuroimaging Initiative
Polygenic risk for AD including APOE was found to associate with plasma p-tau181 independent of diagnostic and Aβ pathology status, while polygenic risk for AD beyond APOE was associated with plasma p-tau181 only in MCI and Aβ-positive individuals. These results extend the knowledge about the relation between genetic risk for AD and p-tau181, and further support the usefulness of plasma p-tau181 as a biomarker of AD.\nRecent studies suggest that plasma phosphorylated tau181 (p-tau181) is a highly specific biomarker for Alzheimer's disease (AD)-related tau pathology. It has great potential for the diagnostic and prognostic evaluation of AD, since it identifies AD with the same accuracy as tau PET and CSF p-tau181 and predicts the development of AD dementia in cognitively unimpaired (CU) individuals and in those with mild cognitive impairment (MCI). Plasma p-tau181 may also be used as a biomarker in studies exploring disease pathogenesis, such as genetic or environmental risk factors for AD-type tau pathology. The aim of the present study was to investigate the relation between polygenic risk scores (PRSs) for AD and plasma p-tau181.\nData from the Alzheimer's Disease Neuroimaging Initiative (ADNI) was used to examine the relation between AD PRSs, constructed based on findings in recent genome-wide association studies, and plasma p-tau181, using linear regression models. Analyses were performed in the total sample (n = 818), after stratification on diagnostic status (CU (n = 236), MCI (n = 434), AD dementia (n = 148)), and after stratification on Aβ pathology status (Aβ positives (n = 322), Aβ negatives (n = 409)).\n), while the non-APOE PRSs were associated with plasma p-tau181 in Aβ positives only (p = 0.02).\nCONCLUSIONS\nBACKGROUND\nMETHODS\nRESULT
Leveraging large multi-center cohorts of Alzheimer disease endophenotypes to understand the role of Klotho heterozygosity on disease risk
Two genetic variants in strong linkage disequilibrium (rs9536314 and rs9527025) in the Klotho (KL) gene, encoding a transmembrane protein, implicated in longevity and associated with brain resilience during normal aging, were recently shown to be associated with Alzheimer disease (AD) risk in cognitively normal participants who are APOE ε4 carriers. Specifically, the participants heterozygous for this variant (KL-SVHET+) showed lower risk of developing AD. Furthermore, a neuroprotective effect of KL-VSHET+ has been suggested against amyloid burden for cognitively normal participants, potentially mediated via the regulation of redox pathways. However, inconsistent associations and a smaller sample size of existing studies pose significant hurdles in drawing definitive conclusions. Here, we performed a well-powered association analysis between KL-VSHET+ and five different AD endophenotypes; brain amyloidosis measured by positron emission tomography (PET) scans (n = 5,541) or cerebrospinal fluid Aβ42 levels (CSF; n = 5,093), as well as biomarkers associated with tau pathology: the CSF Tau (n = 5,127), phosphorylated Tau (pTau181; n = 4,778) and inflammation: CSF soluble triggering receptor expressed on myeloid cells 2 (sTREM2; n = 2,123) levels. Our results found nominally significant associations of KL-VSHET+ status with biomarkers for brain amyloidosis (e.g., CSF Aβ positivity; odds ratio [OR] = 0.67 [95% CI, 0.55–0.78], β = 0.72, p = 0.007) and tau pathology (e.g., biomarker positivity for CSF Tau; OR = 0.39 [95% CI, 0.19–0.77], β = -0.94, p = 0.007, and pTau; OR = 0.50 [95% CI, 0.27–0.96], β = -0.68, p = 0.04) in cognitively normal participants, 60–80 years old, who are APOE e4-carriers. Our work supports previous findings, suggesting that the KL-VSHET+ on an APOE ε4 genotype background may modulate Aβ and tau pathology, thereby lowering the intensity of neurodegeneration and incidence of cognitive decline in older controls susceptible to AD
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