312 research outputs found
Relations between cognition and motricity in children with neonatal arterial ischemic stroke
Introduction and goalPerinatal arterial ischemic stroke (PAIS) affects one child for 4000 births. The few studies about cognitive development specific to PAIS showed that cognitive performances in this population do not follow up a normal development (Westmacott et al., 2010; Ricci et al., 2008). Based on new data about relation between motricity and cognition (Smits-Engelsman et Hill, 2012), and on the theory of the embodied cognition, led us to hypothesize that cognitive performances would be correlated to the motor performances in children with PAIS.Patients and methodologyWe tested 77 7 years old children meeting the criteria of neonatal AIS, with a diagnosis before the 28th day of life relying on cerebral imagery. After excluding children with seizure and bi-hemispheric lesion, 56 children participated to our study. The cognitive evaluation was performed with the Wechsler Intelligence Scale for Children (WISC-4), the motor evaluation relied on testing of gross motor of the upper arm (Box and Block Test) and fine prehension test (“Nine Hole Peg Test”). The localisation of the lesion, the economic level of parents, the gender, sensory impairments and the presence of hemiplegia were collected. We analyzed these results with simple linear regression.ResultsThe main result of our study is the significative correlation (P<0.03) between scores of the WISC4 (except for working memory index) and motor results. In contrast we did not find any correlation between the scores of the WISC4 and the presence of hemiplegia or with lesion localization.DiscussionMany brain networks develop during the first year through sensorimotor experiences, which contribute to the emergence of knowledge. This concept of development, supported by the approach embodied cognition, can explain the correlations between cognition and motor found in our work and in several studies with children with other early neurological damage
Nambu-Poisson manifolds and associated n-ary Lie algebroids
We introduce an n-ary Lie algebroid canonically associated with a
Nambu-Poisson manifold. We also prove that every Nambu-Poisson bracket defined
on functions is induced by some differential operator on the exterior algebra,
and characterize such operators. Some physical examples are presented
The Schouten-Nijenhuis bracket, cohomology and generalized Poisson structures
Newly introduced generalized Poisson structures based on suitable
skew-symmetric contravariant tensors of even order are discussed in terms of
the Schouten-Nijenhuis bracket. The associated `Jacobi identities' are
expressed as conditions on these tensors, the cohomological contents of which
is given. In particular, we determine the linear generalized Poisson structures
which can be constructed on the dual spaces of simple Lie algebras.Comment: 29 pages. Plain TeX. Phyzzx needed. An example and some references
added. To appear in J. Phys.
Classical and Quantum Nambu Mechanics
The classical and quantum features of Nambu mechanics are analyzed and
fundamental issues are resolved. The classical theory is reviewed and developed
utilizing varied examples. The quantum theory is discussed in a parallel
presentation, and illustrated with detailed specific cases. Quantization is
carried out with standard Hilbert space methods. With the proper physical
interpretation, obtained by allowing for different time scales on different
invariant sectors of a theory, the resulting non-Abelian approach to quantum
Nambu mechanics is shown to be fully consistent.Comment: 44 pages, 1 figure, 1 table Minor changes to conform to journal
versio
Etude morphostructurale de la zone sud des rides Nouvelle-Calédonie et Loyauté (Zone Economique Exclusive de Nouvelle-Calédonie, Pacifique Sud-Ouest)
Les données de la campagne ZoNéCo 1 permettent de préciser la morphostructure du Sud des rides calédonienne et Loyauté qui s'avèrent plus complexes que les cartes précédentes ne le montraient, mais on retrouve les principales structures de la région Calédonie-Loyauté. L'imagerie met en évidence les zones de roches nues ou encroûtées, la présence d'écoulements gravitaires du Sud du bassin des Loyauté vers le bassin Sud-Fidjien. (Résumé d'auteur
On the generalizations of Poisson structures
The characterization of the Nambu-Poisson n-tensors as a subfamily of the
Generalized-Poisson ones recently introduced (and here extended to the odd
order case) is discussed. The homology and cohomology complexes of both
structures are compared, and some physical considerations are made.Comment: Latex file. 12 pages. Trivial changes, a misprint (subindices)
corrected. To appear in J. Phys. A (letters
Promoting the use of Motor Function Measure (MFM) as outcome measure in patients with Duchenne Muscular Dystrophy (DMD) treated by corticosteroids
ObjectivesAssessing muscle function is a key step in measuring changes and evaluating the outcomes of therapeutic interventions in Duchenne Muscular Dystrophy (DMD). Regarding the large use of corticosteroids (CS) in this population to delay the loss of function, our goal was to monitor the evolution of motor function in patients with DMD treated by corticosteroids (CS) and to study the responsiveness of Motor Function Measure (MFM) in this population in order to provide an estimation of the number of subject needed for a clinical trial.MethodA total of 76 patients with DMD, aged 5.9 to 11.8 years, with at least 6 months of follow-up and 2 MFM were enrolled, 30 in the CS treated group (8±1.62 y) and 46 in the untreated group (7.91±1.50 y).ResultsThe relationship between MFM scores and age was studied in CS treated patients and untreated patients. The evolution of these scores was compared between groups, on a 6-, 12- and 24-month period by calculating slopes of change and standardized response mean. At 6, 12 and 24 months, significant differences in the mean score change were found, for all MFM scores, between CS treated patients and untreated patients. For D1 subscore specifically, at 6 months, the increase is significant in the treated group (11.3±14%/y; SRM 0.8) while a decrease is observed in the untreated group (–17.8±17.7%/y; SRM 1). At 12 and 24 months, D1 subscore stabilized for treated patients but declined significantly for untreated boys (–15.5±15.1%/y; SRM 1 at 12 mo and–18.8±7.1%/y; SRM 2.6 at 24 mo). 21 patients lost the ability to walk during the study: 6 in the CS treated group (25% at 24 months, mean age: 10.74±1.28 y) and 15 in the untreated group (64.71% at 24 months, mean age: 9.20±1.78 y).Discussion and conclusionPatients with DMD treated by CS present a different course of the disease described in this paper using the MFM. Based on these results, an estimation of the number of patients needed for clinical trial could be done
Measurement of the Longitudinal Spin Transfer to Lambda and Anti-Lambda Hyperons in Polarised Muon DIS
The longitudinal polarisation transfer from muons to lambda and anti-lambda
hyperons, D_LL, has been studied in deep inelastic scattering off an
unpolarised isoscalar target at the COMPASS experiment at CERN. The spin
transfers to lambda and anti-lambda produced in the current fragmentation
region exhibit different behaviours as a function of x and xF . The measured x
and xF dependences of D^lambda_LL are compatible with zero, while
D^anti-lambda_LL tends to increase with xF, reaching values of 0.4 - 0.5. The
resulting average values are D^lambda_LL = -0.012 +- 0.047 +- 0.024 and
D^anti-lambda_LL = 0.249 +- 0.056 +- 0.049. These results are discussed in the
frame of recent model calculations.Comment: 13 pages, 7 figure
Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high
We measured the longitudinal double spin asymmetries for single
hadron muo-production off protons and deuterons at photon virtuality <
1(GeV/) for transverse hadron momenta in the range 0.7
GeV/ to 4 GeV/ . They were determined using COMPASS data taken
with a polarised muon beam of 160 GeV/ or 200 GeV/ impinging on
polarised or targets. The experimental
asymmetries are compared to next-to-leading order pQCD calculations, and are
sensitive to the gluon polarisation inside the nucleon in the range
of the nucleon momentum fraction carried by gluons
Interplay among transversity induced asymmetries in hadron leptoproduction
In the fragmentation of a transversely polarized quark several left-right
asymmetries are possible for the hadrons in the jet. When only one unpolarized
hadron is selected, it exhibits an azimuthal modulation known as Collins
effect. When a pair of oppositely charged hadrons is observed, three
asymmetries can be considered, a di-hadron asymmetry and two single hadron
asymmetries. In lepton deep inelastic scattering on transversely polarized
nucleons all these asymmetries are coupled with the transversity distribution.
From the high statistics COMPASS data on oppositely charged hadron-pair
production we have investigated for the first time the dependence of these
three asymmetries on the difference of the azimuthal angles of the two hadrons.
The similarity of transversity induced single and di-hadron asymmetries is
discussed. A new analysis of the data allows to establish quantitative
relationships among them, providing for the first time strong experimental
indication that the underlying fragmentation mechanisms are all driven by a
common physical process.Comment: 6 figure
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