Les planétariums : des musées scientifiques en effervescence

Responsable du planétarium de Montréal, l’auteur apporte ici le point de vue nord américain sur l’évolution exponentielle des innovations technologiques constatée depuis une dizaine d’années, les conséquences de cet avènement de l’ère du numérique sur la gestion et l’organisation des établissements ainsi que son impact sur le renouvellement et la qualité des productions désormais proposées au public

Les mirades en el territori: les fortificacions al massís de l’Albera, el vessant més oriental dels Pirineus

L’Albera admet una doble mirada: és una barrera física natural, que ha estat límit i frontera, i és la serralada més baixa dels Pirineus, la més important zona de pas terrestre de la serralada pirinenca, la que permet el pas entre l’Europa central-oriental i la península Ibèrica i Àfrica. Aquest pas ha afavorit el desenvolupament de la mateixa cultura identitària catalana a les dues bandes del massís. Territoris culturalment units, administrativament diferents, fet que ha portat a vigilar i defensar els seus passos d’accés. S’han construït fortificacions per salvaguardar i protegir. Unes construccions que han evolucionat segons les tècniques de la guerra per ser el màxim d’eficients i útils. El que dóna com a resultat una tipologia de fortificacions des de fa més de dos mil anys.The Albera mountain range allows a double interpretation: it is a natural physical barrier that has been limit and border, and it is the lowest range of the Pyrenees, the most important overland pass of the Pyrenees range, that connects central and eastern Europe with the Iberian Peninsula and Africa. This crossroad has led to the development of the same Catalan culture and identity on both sides of the range. Culturally united territories, but under different administrations which why their access points had to be controlled and defended. Fortifications have been built to safeguard and to protect. Constructions which have evolved according to the techniques of war to be most efficient and useful. The result is a typology of fortifications from over two thousand years of history

Neural changes associated with semantic processing in healthy aging despite intact behavioral performance

Semantic memory recruits an extensive neural network including the left inferior prefrontal cortex (IPC) and the left temporoparietal region, which are involved in semantic control processes, as well as the anterior temporal lobe region (ATL) which is considered to be involved in processing semantic information at a central level. However, little is known about the underlying neuronal integrity of the semantic network in normal aging. Young and older healthy adults carried out a semantic judgment task while their cortical activity was recorded using magnetoencephalography (MEG). Despite equivalent behavioral performance, young adults activated the left IPC to a greater extent than older adults, while the latter group recruited the temporoparietal region bilaterally and the left ATL to a greater extent than younger adults. Results indicate that significant neuronal changes occur in normal aging, mainly in regions underlying semantic control processes, despite an apparent stability in performance at the behavioral level

Analyse des impacts de l'ouverture du passage nord-ouest en termes de développement durable

L’ouverture du passage du nord-ouest, qui se fait au rythme le plus rapide jamais enregistré, provoque un ensemble d’impacts actuels et potentiels. L’objectif principal de cet essai est de les analyser en termes de développement durable par rapport à quatre de ses composantes (économie, environnement, société et gouvernance). Cette analyse se fait à l’aide d’une grille d’analyse de la durabilité de problématique. Celle-ci se conclut sur un verdict de non-durabilité principalement à cause des faibles résultats des composantes reliées aux aspects sociaux et environnementaux. Le présent essai sert d’outil d’aide à la gestion pour les acteurs impliqués dans les développements et la gestion des impacts entourant l’ouverture du passage du nord-ouest

Pour une politique ambitieuse des données publiques

Ce rapport présente une étude sur la réutilisation des données publiques, menée pour la Délégation aux usages de l’Internet du Ministère de l’Enseignement supérieur et de la Recherche dans le cadre du Master d’Action Publique de l’École des Ponts ParisTech. Il met en perspective la problématique et les enjeux de l’Open Data, propose un état des lieux de la réutilisation des données publiques en France, et dessine trois scénarios prospectifs pour l’évolution future de ce mouvement. Elle présente seize propositions pour une politique nationale ambitieuse d’ouverture et de réutilisation des données publiques. Quatre élèves de l’École des Ponts ParisTech, Pierre-Henri Bertin, Romain Lacombe, François Vauglin et Alice Vieillefosse ont mené cette analyse de septembre 2010 à janvier 2011, en rencontrant les acteurs clés de la réutilisation des données publiques, en prenant part à des colloques internationaux, et en s’appuyant sur la bibliographie existante

Effect of anti-inflammatory agents on transforming growth factor beta over-expressing mouse brains: a model revised.

BACKGROUND: The over-expression of transforming growth factor beta-1(TGF-beta1) has been reported to cause hydrocephalus, glia activation, and vascular amyloidbeta (Abeta) deposition in mouse brains. Since these phenomena partially mimic the cerebral amyloid angiopathy (CAA) concomitant to Alzheimer's disease, the findings in TGF-beta1 over-expressing mice prompted the hypothesis that CAA could be caused or enhanced by the abnormal production of TGF-beta1. This idea was in accordance with the view that chronic inflammation contributes to Alzheimer's disease, and drew attention to the therapeutic potential of anti-inflammatory drugs for the treatment of Abeta-elicited CAA. We thus studied the effect of anti-inflammatory drug administration in TGF-beta1-induced pathology. METHODS: Two-month-old TGF-beta1 mice and littermate controls were orally administered pioglitazone, a peroxisome proliferator-activated receptor-gamma agonist, or ibuprofen, a non steroidal anti-inflammatory agent, for two months. Glia activation was assessed by immunohistochemistry and western blot analysis; Abeta precursor protein (APP) by western blot analysis; Abeta deposition by immunohistochemistry, thioflavin-S staining and ELISA; and hydrocephalus by measurements of ventricle size on autoradiographies of brain sections. Results are expressed as means +/- SD. Data comparisons were carried with the Student's T test when two groups were compared, or ANOVA analysis when more than three groups were analyzed. RESULTS: Animals displayed glia activation, hydrocephalus and a robust thioflavin-S-positive vascular deposition. Unexpectedly, these deposits contained no Abeta or serum amyloid P component, a common constituent of amyloid deposits. The thioflavin-S-positive material thus remains to be identified. Pioglitazone decreased glia activation and basal levels of Abeta42- with no change in APP contents - while it increased hydrocephalus, and had no effect on the thioflavin-S deposits. Ibuprofen mimicked the reduction of glia activation caused by pioglitazone and the lack of effect on the thioflavin-S-labeled deposits. CONCLUSIONS: i) TGF-beta1 over-expressing mice may not be an appropriate model of Abeta-elicited CAA; and ii) pioglitazone has paradoxical effects on TGF-beta1-induced pathology suggesting that anti-inflammatory therapy may reduce the damage resulting from active glia, but not from vascular alterations or hydrocephalus. Identification of the thioflavin-S-positive material will facilitate the full appraisal of the clinical implication of the effects of anti-inflammatory drugs, and provide a more thorough understanding of TGF-beta1 actions in brain

A MEG study of the neural substrates of semantic processing in semantic variant primary progressive aphasia

Despite a well-documented pattern of semantic memory (SM) impairment, the patterns of brain activation during semantic processing in svPPA still remain poorly understood. The current study aimed to investigate the neural substrates of residual semantic processing in the context of this significant but selective SM impairment, through the case study of one svPPA patient. One svPPA patient (EC) and six elderly controls carried out a general-level semantic categorization task (biological and manufactured objects) while their brain activity was recorded using magnetoencephalography (MEG). Despite similar behavioral performance, EC showed hyperactivation of the left inferior temporal gyrus (ITG) and right anterior temporal lobe (ATL) relative to controls. This suggests that periatrophic regions within the ATL region may support preserved semantic abilities in svPPA. These results thus contribute to our understanding of the brain regions which are recruited to compensate for bilateral atrophy of the ATL and ensure residual semantic processing in svPPA

Improving proton therapy by metal-containing nanoparticles:Nanoscale insights

The use of nanoparticles to enhance the effect of radiation-based cancer treatments is a growing field of study and recently, even nanoparticle-induced improvement of proton therapy performance has been investigated. Aiming at a clinical implementation of this approach, it is essential to characterize the mechanisms underlying the synergistic effects of nanoparticles combined with proton irradiation. In this study, we investigated the effect of platinum- and gadolinium-based nanoparticles on the nanoscale damage induced by a proton beam of therapeutically relevant energy (150 MeV) using plasmid DNA molecular probe. Two conditions of irradiation (0.44 and 3.6 keV/mu m) were considered to mimic the beam properties at the entrance and at the end of the proton track. We demonstrate that the two metal-containing nanoparticles amplify, in particular, the induction of nanosize damages (&gt;2 nm) which are most lethal for cells. More importantly, this effect is even more pronounced at the end of the proton track. This work gives a new insight into the underlying mechanisms on the nanoscale and indicates that the addition of metal-based nanoparticles is a promising strategy not only to increase the cell killing action of fast protons, but also to improve tumor targeting.</p