525 research outputs found
Métacognition : intervention thérapeutique autour de la conscience des troubles chez des patients souffrant de traumatisme crùnio-cérébral grave
Unawareness related to brain injury has implications for participation in rehabilitation, functional outcomes, and the emotional well being of patients after an acquired brain injury. However, the development of interventions for improving self-awareness is at an early stage, and research on the effectiveness of interventions is limited. The present paper is an investigation into the efficacy of a metacognitive program on self-awareness in people who have had an acquired brain injury. An experimental group of three patients were included in a âcross-over designâ protocol including data from neuropsychological evaluations, cognitive complaints, behavioral and emotional changes. In comparison, a social intervention (communicative abilities, social interaction) was proposed to four other patients in order to estimate the specific effects of the metacognitive program. While no specific effect of the metacognitive program was highlighted on cognitive impairments, a post-intervention assessment indicated that participants had significantly improved behavioral limitations, suggesting a benefit of the metacognitive and social rehabilitations on behavior skills. Because benefits are similar whatever the program, it seems that social functioning implication in rehabilitation process needs to be taken into account in forthcoming interventions
Differential roles of p39MosâXp42Mpk1 cascade proteins on Raf1 phosphorylation and spindle morphogenesis in Xenopus oocytes
AbstractFully-grown G2-arrested Xenopus oocytes resume meiosis upon hormonal stimulation. Resumption of meiosis is characterized by germinal vesicle breakdown, chromosome condensation, and organization of a bipolar spindle. These cytological events are accompanied by activation of MPF and the p39MosâMEK1âXp42Mpk1âp90Rsk pathways. The latter cascade is activated upon p39Mos accumulation. Using U0126, a MEK1 inhibitor, and p39Mos antisense morpholino and phosphorothioate oligonucleotides, we have investigated the role of the members of the p39MosâMEK1âXp42Mpk1âp90Rsk in spindle morphogenesis. First, we have observed at a molecular level that prevention of p39Mos accumulation always led to MEK1 phosphorylation defects, even when meiosis was stimulated through the insulin Ras-dependent pathway. Moreover, we have observed that Raf1 phosphorylation that occurs during meiosis resumption was dependent upon the activity of MEK1 or Xp42Mpk1 but not p90Rsk. Second, inhibition of either p39Mos accumulation or MEK1 inhibition led to the formation of a cytoplasmic aster-like structure that was associated with condensed chromosomes. Spindle morphogenesis rescue experiments using constitutively active Rsk and purified murine Mos protein suggested that p39Mos or p90Rsk alone failed to promote meiotic spindle organization. Our results indicate that activation of the p39MosâMEK1âXp42Mpk1âp90Rsk pathway is required for bipolar organization of the meiotic spindle at the cortex
Support for single major genes influencing fat androstenone level and development of bulbo-urethral glands in young boars
A two-step genetic analysis was performed on data collected in a fourgeneration selection experiment comprising a control and a selected line in a Large White-Landrace crossbred population. The two-trait selection index used for choosing replacement boars of the selected line included fat androstenone level and the average thickness of right and left bulbo-urethral glands, the latter trait being an indicator of the sexual maturity status of young boars. Fat androstenone level was determined on a biopsy sample of backfat taken at 118 kg liveweight, whereas bulbo-urethral gland size was measured by echotomography, using a rectal probe, at 99 kg liveweight. A total of 949 entire males, from 57 sires and 353 dams, were recorded for both traits. In the first step of analysis, REML genetic parameters were estimated using a bivariate animal model. Heritability estimates (± SE) were 0.55 ± 0.07 for fat androstenone level and 0.63 ± 0.05 for bulbo-urethral gland size. A fairly close genetic correlation (0.68 ± 0.05) was found between the two traits. The second step of analysis consisted in testing the hypothesis of a mixed mode of inheritance (polygenes + major gene) for each trait using segregation analysis methods. A major two-allele gene was found to affect fat androstenone level. Under the genetic model that best explained the situation, the âlow androstenoneâ allele (L) is completely dominant over the âhigh androstenoneâ allele (H), and the difference between HH and LL (or HL) genotypes amounts to three SD units of the trait. A twoallele major gene was also shown to influence bulbo-urethral gland size (difference close to two SD units between the two homozygous genotypes) with a probably incomplete dominance of the âsmall sizeâ allele. There was no evidence for linkage of these genes with the swine leukocyte antigen (SLA) system. Whether these two postulated major genes are a unique gene or not is discussed.Cette Ă©tude concerne une analyse gĂ©nĂ©tique, en deux Ă©tapes, des donnĂ©es recueillies dans les quatre gĂ©nĂ©rations dâune expĂ©rience de sĂ©lection comportant une lignĂ©e tĂ©moin et une lignĂ©e sĂ©lectionnĂ©e dans une population croisĂ©e Ă base de Large White et de Landrace. Lâindice Ă deux caractĂšres utilisĂ© pour le choix des verrats de la lignĂ©e sĂ©lectionnĂ©e combinait la teneur en androstĂ©none du gras et lâĂ©paisseur moyenne des glandes bulbo-urĂ©thrales droite et gauche, ce dernier caractĂšre Ă©tant un indicateur du statut de maturitĂ© sexuelle des jeunes verrats. La teneur en androstĂ©none a Ă©tĂ© mesurĂ©e sur une biopsie de gras dorsal prĂ©levĂ©e Ă 118 kg de poids vif alors que le dĂ©veloppement des glandes bulbo-urĂ©thrales a Ă©tĂ© mesurĂ© par Ă©chotomographie, Ă lâaide dâune sonde rectale, Ă 99 kg de poids vif. Au total, 9l,9 mĂąles entiers, issus de 57 pĂšres et 353 mĂšres, ont Ă©tĂ© mesurĂ©s pour lâun et lâautre caractĂšre. Dans la premiĂšre Ă©tape de lâanalyse, les paramĂštres gĂ©nĂ©tiques des deux caractĂšres ont Ă©tĂ© estimĂ©s Ă lâaide dâune procĂ©dure REML appliquĂ©e Ă un modĂšle animal bicaractĂšre. Les estimĂ©es dâhĂ©ritabilitĂ© (± erreur standard) sont 0,55 ± 0,07 pour la teneur en androstĂ©none du gras et 0,63 ± 0,05 pour lâĂ©paisseur moyenne des glandes bulbo-urĂ©thrales. Une corrĂ©lation gĂ©nĂ©tique relativement Ă©levĂ©e (0,68 ± 0,05) a Ă©tĂ© trouvĂ©e entre les deux caractĂšres. Une seconde Ă©tape de lâĂ©tude a consistĂ© Ă tester, Ă lâaide de mĂ©thodes dâanalyse de sĂ©grĂ©gation, lâhypothĂšse dâun dĂ©terminisme gĂ©nĂ©tique mixte (polygĂšnes + un gĂšne majeur) pour chaque caractĂšre. Un gĂšne Ă effet majeur sur la teneur en androstĂ©none du gras a Ă©tĂ© mis en Ă©vidence : selon le modĂšle gĂ©nĂ©tique le plus explicatif, lâallĂšle « faible» (L) est complĂštement dominant sur lâallĂšle « fort» (H), avec une diffĂ©rence entre les gĂ©notypes HH et LL (ou HL) voisine de trois Ă©carts types phĂ©notypiques du caractĂšre. Un gĂšne Ă effet majeur sur lâĂ©paisseur moyenne des glandes bulbo-urĂ©thrales (diffĂ©rence de lâordre de deux Ă©carts types phĂ©notypiques entre les gĂ©notypes homozygotes) a Ă©galement Ă©tĂ© mis en Ă©vidence avec une dominance probablement incomplĂšte de lâallĂšle «faible». Ces deux gĂšnes ne semblent pas ĂȘtre liĂ©s avec le systĂšme dâhistocompatibilitĂ© majeur (SLA). La possible identitĂ© des deux gĂšnes majeurs postulĂ©s est discutĂ©
Structure and transport in multi-orbital Kondo systems
We consider Kondo impurity systems with multiple local orbitals, such as rare
earth ions in a metallic host or multi--level quantum dots coupled to metallic
leads. It is shown that the multiplet structure of the local orbitals leads to
multiple Kondo peaks above the Fermi energy , and to ``shadow'' peaks
below . We use a slave boson mean field theory, which recovers the strong
coupling Fermi liquid fixed point, to calculate the Kondo peak positions,
widths, and heights analytically at T=0, and NCA calculations to fit the
temperature dependence of high--resolution photoemission spectra of Ce
compounds. In addition, an approximate conductance quantization for transport
through multi--level quantum dots or single--atom transistors in the Kondo
regime due to a generalized Friedel sum rule is demonstrated.Comment: 4 pages, 3 figures. Invited article, 23rd International Conference on
Low Temperature Physics LT23, Hiroshima, Japan 200
Hadamard Regularization
Motivated by the problem of the dynamics of point-particles in high
post-Newtonian (e.g. 3PN) approximations of general relativity, we consider a
certain class of functions which are smooth except at some isolated points
around which they admit a power-like singular expansion. We review the concepts
of (i) Hadamard ``partie finie'' of such functions at the location of singular
points, (ii) the partie finie of their divergent integral. We present and
investigate different expressions, useful in applications, for the latter
partie finie. To each singular function, we associate a partie-finie (Pf)
pseudo-function. The multiplication of pseudo-functions is defined by the
ordinary (pointwise) product. We construct a delta-pseudo-function on the class
of singular functions, which reduces to the usual notion of Dirac distribution
when applied on smooth functions with compact support. We introduce and analyse
a new derivative operator acting on pseudo-functions, and generalizing, in this
context, the Schwartz distributional derivative. This operator is uniquely
defined up to an arbitrary numerical constant. Time derivatives and partial
derivatives with respect to the singular points are also investigated. In the
course of the paper, all the formulas needed in the application to the physical
problem are derived.Comment: 50 pages, to appear in Journal of Mathematical Physic
Spatial Current Patterns, Dephasing and Current Imaging in Graphene Nanoribbons
Using the non-equilibrium Keldysh Green's function formalism, we investigate
the local, non-equilibrium charge transport in graphene nanoribbons (GNRs). In
particular, we demonstrate that the spatial current patterns associated with
discrete transmission resonances sensitively depend on the GNRs' geometry,
size, and aspect ratio, the location and number of leads, and the presence of
dephasing. We identify a relation between the spatial form of the current
patterns, and the number of degenerate energy states participating in the
charge transport. Furthermore, we demonstrate a principle of superposition for
the conductance and spatial current patterns in multiple-lead configurations.
We demonstrate that scanning tunneling microscopy (STM) can be employed to
image spatial current paths in GNR with atomic resolution, providing important
insight into the form of local charge transport. Finally, we investigate the
effects of dephasing on the spatial current patterns, and show that with
decreasing dephasing time, the current patterns evolve smoothly from those of a
ballistic quantum network to those of classical resistor network.Comment: 25 pages, 12 figure
Local spin and charge properties of beta-Ag0.33V2O5 studied by 51V NMR
Local spin and charge properties were studied on beta-Ag0.33V2O5, a
pressure-induced superconductor, at ambient pressure using 51V-NMR and
zero-field-resonance (ZFR) techniques. Three inequivalent Vi sites (i=1, 2, and
3) were identified from 51V-NMR spectra and the principal axes of the
electric-field-gradient (EFG) tensor were determined in a metallic phase and
the following charge-ordering phase. We found from the EFG analysis that the V1
sites are in a similar local environment to the V3 sites. This was also
observed in ZFR spectra as pairs of signals closely located with each other.
These results are well explained by a charge-sharing model where a 3d1 electron
is shared within a rung in both V1-V3 and V2-V2 two-leg ladders.Comment: 12pages, 16figure
L'expérimentation sur le porc chinois en France II. - Performances de production en croisement avec les races européennes
Superconductor-ferromagnet junction phase qubit
We propose a scheme for a phase qubit in an SIFIS junction, consisting of
bulk superconductors (S), a proximity-induced ferromagnet (F), and insulating
barriers (I). The qubit state is constituted by 0 and phase states of the
junction, in which the charging energy of the junction leads to the
superposition of the two states. The qubit is operated by the gate voltage
applied to the ferromagnet, and insensitive to the decoherence sources existing
in other superconducting qubits. We discuss a scalable scheme for qubit
measurement and tunable two-qubit coupling.Comment: 3 pages, 3 figure
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