Search results for "MT"
showing 10 items of 2759 documents
L’utilisation du bois de construction sur l’oppidum de Bibracte, Mont Beuvray (fin du IIe-Ier s. av. notre ère) : types d’assemblage, modes de débita…
2016
International audience
Les objets en bronze en cours de fabrication à Bibracte
2000
National audience
Reactivation of SNURF-SNRPN gene by DNA Methyltransferase inhibitors in a Prader-Willi lymphoblastoid cell line.
2014
Lesion load may predict long-term cognitive dysfunction in multiple sclerosis patients
2015
Background: Magnetic Resonance Imaging (MRI) techniques provided evidences into the understanding of cognitive impairment (CIm) in Multiple Sclerosis (MS). Objectives: To investigate the role of white matter (WM) and gray matter (GM) in predicting long-term CIm in a cohort of MS patients. Methods: 303 out of 597 patients participating in a previous multicenter clinical-MRI study were enrolled (49.4% were lost at follow-up). The following MRI parameters, expressed as fraction (f) of intracranial volume, were evaluated: cerebrospinal fluid (CSF-f), WM-f, GM-f and abnormal WM (AWM-f), a measure of lesion load. Nine years later, cognitive status was assessed in 241 patients using the Symbol Dig…
Key advantages of the leverage points perspective to shape human-nature relations
2021
This perspective paper synthesises the special issue 'Human-nature connectedness as a leverage point for sustainability transformation'. Based on the articles in this special issue, we aim to foster the operationalisation of the leverage points perspective to shape human-nature relations to enable sustainability transformations. Specifically, we draw on four key advantages of the leverage points perspective: (i) the explicit recognition of deep leverage points; (ii) the ability to examine the interactions between shallow and deep system changes; (iii) the combination of causal and teleological modes of research; and (iv) the ability to function as a methodological boundary object. The contr…
Análisis del repertorio musical en los manuales escolares
2021
Una de las concreciones de la pedagogía crítica en la educación musical es la utilización de un repertorio que incorpore las preferencias del alumnado. En este estudio se aborda la presencia de dicho repertorio en los manuales escolares más utilizados en la actualidad. Para ello, se ha accedido a 15 libros de texto, analizando 985 piezas distintas. Las variables empleadas han sido el período histórico o género musical, el estilo dentro del repertorio de la música popular urbana, la antigüedad del autor y la tipología de propuesta didáctica asociada. Los resultados indican que la música popular urbana tiene una escasa presencia en los manuales (8.20%) y no coincide con las preferencias de lo…
Dynamique induite par champ laser femtoseconde intense : alignement moléculaire en milieu gazeux dense et effet Kerr
2011
This thesis is devoted to the study of dynamics induced by intense femtoseconds lasers pulses. The first studied dynamics deals with molecular alignment of CO2-X mixtures (X=CO2, Ar, N2), in dense gases (up to 20 bar). Up to now, this regime has never been studied experimentally. In the field-free regime (after laser/matter interaction), molecular alignment exhibits two components : a permanent alignment and a transient one. The influence of collisions appears through population transfers between rotational states, which leads to a decrease of these two contributions. Permanent alignment relaxation time is only tied to inelastics collisions whereas transient alignment relaxation time is tie…
Ultrabroadband single-cycle terahertz pulses with peak fields of 300 kV cm-1 from a metallic spintronic emitter
2017
To explore the capabilities of metallic spintronic thin-film stacks as a source of intense and broadband terahertz electromagnetic fields, we excite a W/CoFeB/Pt trilayer on a large-area glass substrate (diameter of 7.5 cm) by a femtosecond laser pulse (energy 5.5 mJ, duration 40 fs, wavelength 800 nm). After focusing, the emitted terahertz pulse is measured to have a duration of 230 fs, a peak field of 300 kV cm$^{-1}$ and an energy of 5 nJ. In particular, the waveform exhibits a gapless spectrum extending from 1 to 10 THz at 10% of amplitude maximum, thereby facilitating nonlinear control over matter in this difficult-to-reach frequency range and on the sub-picosecond time scale.
Ultra-nonlocality in density functional theory for photo-emission spectroscopy.
2014
We derive an exact expression for the photo-current of photo-emission spectroscopy using time-dependent current density functional theory (TDCDFT). This expression is given as an integral over the Kohn-Sham spectral function renormalized by effective potentials that depend on the exchange-correlation kernel of current density functional theory. We analyze in detail the physical content of this expression by making a connection between the density-functional expression and the diagrammatic expansion of the photo-current within many-body perturbation theory. We further demonstrate that the density functional expression does not provide us with information on the kinetic energy distribution of…
Investigation of acceptor levels and hole scattering mechanisms in p-gallium selenide by means of transport measurements under pressure
1997
The effect of pressure on acceptor levels and hole scattering mechanisms in p-GaSe is investigated through Hall effect and resistivity measurements under quasi-hydrostatic conditions up to 4 GPa. The pressure dependence of the hole concentration is interpreted through a carrier statistics equation with a single (nitrogen) or double (tin) acceptor whose ionization energies decrease under pressure due to the dielectric constant increase. The pressure effect on the hole mobility is also accounted for by considering the pressure dependencies of both the phonon frequencies and the hole-phonon coupling constants involved in the scattering rates.