Apport de la microscopie électronique sous incidence rasante à l'étude des surfaces, application au laiton 70/30

10ème Congrès International d'Optique des Rayons X et de Microanalyse 10th International Congress on X-Ray Optics and MicroanalysisNational audienceOn montre combien la diffraction des électrons (100 keV) sous incidence rasante aide à la compréhension des données obtenues par spectrométrie Auger. On prend pour exemple l'étude d'une surface oxydée de laiton 70/30. Les résultats sont discutés, et confrontés à ceux obtenus en ESCA. L'influence du frottement sur la composition superficielle est observée

C57BL/6 and Swiss Webster Mice Display Differences in Mobility, Gliosis, Microcavity Formation and Lesion Volume After Severe Spinal Cord Injury

Spinal cord injuries (SCI) are neuropathologies causing enormous physical and emotional anguish as well as irreversibly disabilities with great socio/economic burdens to our society. The availability of multiple mouse strains is important for studying the underlying pathophysiological response after SCI. Although strain differences have been shown to directly affect spontaneous functional recovery following incomplete SCI, its influence after complete lesion of the spinal cord is unclear. To study the influence of mouse strain on recovery after severe SCI, we first carried out behavioral analyses up to 6 weeks following complete transection of the spinal cord in mice with two different genetic backgrounds namely, C57BL/6 and Swiss Webster. Using immunohistochemistry, we then analyzed glial cell reactivity not only at different time-points after injury but also at different distances from the lesion epicenter. Behavioral assessments using CatWalk™ and open field analyses revealed increased mobility (measured using average speed) and differential forelimb gross sensory response in Swiss Webster compared to C57BL/6 mice after complete transection of the spinal cord. Comprehensive histological assessment revealed elevated microglia/macrophage reactivity and a moderate increase in astrogliosis in Swiss Webster that was associated with reduced microcavity formation and reduced lesion volume after spinal cord transection compared to C57BL/6 mice. Our results thus suggest that increased mobility correlates with enhanced gliosis and better tissue protection after complete transection of the spinal cord

Horizon 2019 : bibliothèques en prospective

Colloque organisé du 19 au 21 novembre 2009 à l\u27enssib avec pour but d\u27imaginer l\u27avenir proche des bibliothèques dans le monde occidental. Le colloque s\u27organise en trois temps : "Enjeux et défis", "Quelles missions pour les bibliothèques" et "Hypothèses et scénarios"

Brain Responses to Violet, Blue, and Green Monochromatic Light Exposures in Humans: Prominent Role of Blue Light and the Brainstem

BACKGROUND: Relatively long duration retinal light exposure elicits nonvisual responses in humans, including modulation of alertness and cognition. These responses are thought to be mediated in part by melanopsin-expressing retinal ganglion cells which are more sensitive to blue light than violet or green light. The contribution of the melanopsin system and the brain mechanisms involved in the establishment of such responses to light remain to be established. METHODOLOGY/PRINCIPAL FINDINGS: We exposed 15 participants to short duration (50 s) monochromatic violet (430 nm), blue (473 nm), and green (527 nm) light exposures of equal photon flux (10(13)ph/cm(2)/s) while they were performing a working memory task in fMRI. At light onset, blue light, as compared to green light, increased activity in the left hippocampus, left thalamus, and right amygdala. During the task, blue light, as compared to violet light, increased activity in the left middle frontal gyrus, left thalamus and a bilateral area of the brainstem consistent with activation of the locus coeruleus. CONCLUSION/SIGNIFICANCE: These results support a prominent contribution of melanopsin-expressing retinal ganglion cells to brain responses to light within the very first seconds of an exposure. The results also demonstrate the implication of the brainstem in mediating these responses in humans and speak for a broad involvement of light in the regulation of brain function

Gacyclidine improves the survival and reduces motor deficits in a mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder typified by a massive loss of motor neurons with few therapeutic options. The exact cause of neuronal degeneration is unknown but it is now admitted that ALS is a multifactorial disease with several mechanisms involved including glutamate excitotoxicity. More specifically, N-methyl-D-aspartate (NMDA)-mediated cell death and impairment of the glutamate-transport has been suggested to play a key role in ALS pathophysiology. Thus, evaluating NMDAR antagonists is of high therapeutic interest. Gacyclidine, also named GK11, is a high affinity non-competitive NMDAR antagonist that may protect against motor neuron death in an ALS context. Moreover, GK11 presents a low intrinsic neurotoxicity and has already been used in two clinical trials for CNS lesions. <br/>In the present study, we investigated the influence of chronic administration of two doses of GK11 (0.1 and 1 mg/kg) on the survival and the functional motor activity of hSOD1G93A mice, an animal model of ALS. Treatment started at early symptomatic age (60 days) and was applied bi-weekly until the end stage of the disease. We first confirmed that functional alteration of locomotor activity was evident in the hSOD1G93A transgenic female mice by 60 days of age. A low dose of GK11 improved the survival of the mice by 4.3% and partially preserved body weight. Improved life span was associated with a delay in locomotor function impairment. Conversely, the high dose treatment worsened motor functions. <br/>These findings suggest that chronic administration of GK11beginning at early symptomatic stage may be beneficial for patients with ALS

L'identité nationale vue par les jeunes Franciliens

Perrin Evelyne. L'identité nationale vue par les jeunes Franciliens. In: Raison présente, n°169, 1er trimestre 2009. Les usages politiques de l'identité. pp. 37-44

Les métropoles du monde arabe, Bulletin de la Société Languedocienne de Géographie, n° 2-3, avril-sept. 1986

Perrin Evelyne. Les métropoles du monde arabe, Bulletin de la Société Languedocienne de Géographie, n° 2-3, avril-sept. 1986. In: Les Annales de la recherche urbaine, N°38, 1988. Villes et Etats. p. 113

Olivier Crevoisier, Roberto Camagni (dir.), Les milieux urbains : innovation, systèmes de production et ancrage ?, 2000

Perrin Evelyne. Olivier Crevoisier, Roberto Camagni (dir.), Les milieux urbains : innovation, systèmes de production et ancrage ?, 2000. In: Les Annales de la recherche urbaine, N°89, 2001. Le foisonnement associatif. pp. 179-181

Jean Philippe, Pierre-Yves Leo, Louis-Marie Boulianne (dir.), Services et métropoles, formes urbaines et changement économique, Collection Villes et Entreprises, 1999

Perrin Evelyne. Jean Philippe, Pierre-Yves Leo, Louis-Marie Boulianne (dir.), Services et métropoles, formes urbaines et changement économique, Collection Villes et Entreprises, 1999. In: Les Annales de la recherche urbaine, N°86, 2000. Développements et coopérations. pp. 163-164