Détection d'incohérences de niveau de détail dans des données collaboratives

National audienceAlors qu'il est possible de définir le niveau de détail de bases de données géographiques classiques, cela n'est pas le cas pour les données collaboratives, qui contiennent fréquemment des niveaux de détail hétérogènes. Cette hétérogénéité est un véritable frein pour la réalisation de cartes, notamment quand on utilise les techniques traditionnelles, comme la généralisation, pour produire une carte à partir d'une base de données. Cet article propose une méthode pour estimer le niveau de détail de données issues de sources collaboratives. Ensuite, les incohérences entre objets de la carte à différents niveaux de détail, qui empêchent la réalisation de cartes lisibles, sont détectées automatiquement. Des propositions sont faites pour, ensuite, harmoniser le niveau de détail des objets de la carte. La méthode a été implémentée et des résultats sont présentés sur des données OpenStreetMap

Annotation of Toponyms in TEI Digital Literary Editions and Linking to the Web of Data

International audienceThis paper aims to discuss the challenges and benefits of the annotation of place names in literary texts and literary criticism. We shall first highlight the problems of encoding spatial information in digital editions using the TEI format by means of two manual annotation experiments and the discussion of various cases. This will lead to the question of how to use existing semantic web resources to complement and enrich toponym markup , in particular to provide mentions with precise geo-referencing. Finally the automatic annotation of a large corpus will show the potential of visualizing places from texts, by illustrating an analysis of the evolution of literary life from the spatial and geographical point of view.Este artigo aborda as dificuldades e as vantagens da anotação dos nomes de lugar em textos literários e de crítica literária. Começamos por realçar os problemas de codifi-cação da informação espacial em edições digitais usando o formato TEI, através de duas experiências de anotação manual e da análise de diversos casos. Isto conduzirá à questão de como utilizar os recursos da web semântica para complementar e enrique-cer a marcação de topónimos, em particular com georreferenciação rigorosa. Por último, a anotação automática de um grande corpus irá mostrar o potencial de visuali-zação de locais a partir de textos, ilustrando a análise da evolução da vida literária segundo um ponto de vista espacial e geográfico. Palavras-chave: estudos literários digitais; topónimos; web semântica; bases de dados geográficas; mapas e visualizações

Implications of glial nitric oxide in neurodegenerative diseases

Nitric oxide (NO) is a pleiotropic janus-faced molecule synthesized by nitric oxide synthases (NOS) which plays a critical role in a number of physiological and pathological processes in humans. The physiological roles of NO depend on its local concentrations, as well as its availability and the nature of downstream target molecules. Its double-edged sword action has been linked to neurodegenerative disorders. Excessive NO production, as the evoked by inflammatory signals, has been identified as one of the major causative reasons for the pathogenesis of several neurodegenerative diseases. Moreover, excessive NO synthesis under neuroinflammation leads to the formation of reactive nitrogen species and neuronal cell death. There is an intimate relation between microglial activation, NO and neuroinflammation in the human brain. The role of NO in neuroinflammation has been defined in animal models where this neurotransmitter can modulate the inflammatory process acting on key regulatory pathways, such as those associated with excitotoxicity processes induced by glutamate accumulation and microglial activation. Activated glia express inducible NOS and produce NO that triggers calcium mobilization from the endoplasmic reticulum, activating the release of vesicular glutamate from astroglial cells resulting in neuronal death. This change in microglia potentially contributes to the increased age-associated susceptibility and neurodegeneration. In the current review, information is provided about the role of NO, glial activation and age-related processes in the central nervous system (CNS) that may be helpful in the isolation of new therapeutic targets for aging and neurodegenerative diseases

Paris dans les récits de voyage d’écrivains arabes : repérage, analyse sémantique et cartographie de toponymes

À la croisée du traitement du langage naturel, des études littéraires et des humanités spatiales, nous présentons dans cet article une approche pour cartographier les modalités sémantiques positives ou négatives associées aux noms de lieux dans des textes en arabe. La chaîne de traitement comprend le repérage des entités nommées de lieu, l’analyse sémantique de leur contexte (opinions, émotions et sentiments), ainsi que la cartographie de leurs instances sur des cartes géographiques. Notre corpus de travail comprend six récits de voyage à Paris de grands écrivains arabes des xixe et xxe siècles. Des approches à base de règles et à base d’apprentissage automatique ont été expérimentées et évaluées pour le repérage des entités nommées de lieu et pour l’analyse sémantique. Les résultats de notre étude permettent de confirmer l’apport de cette méthode automatique pour la recherche littéraire, en contribuant à une étude sémantique de vaste ampleur.We present in this paper an automated method to map out positive or negative semantic modalities associated with place names in Arabic travelogue literature. This research sits at the crossroads of Natural Language Processing, Literary Studies, and Digital Humanities. Our pipeline identifies place named entities, analyzes their semantic context (with regard to opinions, sentiments and emotions), and locates the place names on geographic maps. Our corpus includes six travel writings on Paris from some of the most influential Arab writers of the 19th and 20th centuries. We evaluate rule-based and machine-learning approaches for their efficacy in named entity recognition and semantic analysis. The results of our automated analysis confirm, to a great extent, the judgements and interpretations of traditional critical scholarship on these Arabic literary texts

7-Nitroindazole down-regulates dopamine/DARPP-32 signaling in neostriatal neurons in a rat model of Parkinson's disease

Neuronal nitric oxide synthase (nNOS) is involved in the regulation of diverse intracellular messenger systems in the brain. Nitric Oxide (NO) contributes to inducing signaling cascades that involve a complex pattern of phosphorylation of DARPP-32 (in Thr-34), which controls the phosphoproteins involved in neuronal activation. However, the role of NO in the pathophysiology of Parkinson's disease (PD) and its effect in striatal neurons have been scarcely explored. In the present work, we investigate the effects of a nitric oxide synthase (NOS) inhibitor, 7-nitroindazole (7-NI) in the nigrostriatal pathway of striatal 6-hydroxydopamine (6-OHDA) lesioned rats. Our quantitative histological findings show that treatment with 7-NI significantly reduced 6-OHDA-induced dopaminergic damage in the dorsolateral striatum and Substantia Nigra pars compacta (SNpc). Moreover, 6-OHDA lesioned rats show a significant increase of nNOS+ and Phospho-Thr34-DARPP-32+ cells, accompanied by a consequent decrease of total DARPP-32+ cells, which suggests an imbalance of NO activity in the DA-depleted striatum, which is also reflected in behavioral studies. Importantly, these effects are reverted in the group treated with 7-NI. These results show a clear link between the state of phosphorylation of DARPP-32 and parkinsonism, which is regulated by nNOS. This new evidence suggests a prominent role for nitric oxide in the neurotransmitter balance within the basal ganglia in the pathophysiology of experimental parkinsonism.This work was supported by grants from the Spanish Ministry of Science (SAF 2007-62262), FIS (PI/2010/02827) and CIBERNED (Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas)

Fueling Time Machine: Information Extraction from Retro-Digitised Address Directories

International audienc

Persistent phagocytic characteristics of microglia in the substantia nigra of long-term Parkinsonian macaques

Patients with Parkinson's disease show persistent microglial activation in the areas of the brain where the degeneration of dopaminergic neurons takes place. The reason for maintaining this activated state is still unknown, but it is thought that this persistent microglial activation may contribute to the degeneration of dopaminergic neurons. In this study, we report the microanatomical details of microglia and the relationship between microglia and neurons in the substantia nigra pars compacta of Parkinsonian monkeys years after insult with MPTP. We observed that microglial cells appear polarized toward dopaminergic neurons in MPTP-treated macaques compared to untreated animals and present clear phagocytic characteristics, such as engulfing gliaptic contacts, an increase in Golgi apparatus protein machinery and ball-and-chain phagocytic buds. These results demonstrate that activated microglia maintain phagocytic characteristics years after neurotoxin insult, and phagocytosis may be a key contributor to the neurodegenerative process

ROCK/Cdc42-mediated microglial motility and gliapse formation lead to phagocytosis of degenerating dopaminergic neurons in vivo

The role of microglial motility in the context of adult neurodegeneration is poorly understood. In the present work, we investigated the microanatomical details of microglia-neuron interactions in an experimental mouse model of Parkinson’s disease following the intraperitoneal injection of MPTP. The specific intoxication of dopaminergic neurons induces the cellular polarization of microglia, leading to the formation of body-to-body neuron-glia contacts, called gliapses, which precede neuron elimination. Inhibiting ROCK/Cdc42-mediated microglial motility in vivo blocks the activating features of microglia, such as increased cell size and number of filopodia and diminishes their phagocyting/secreting domains, as the reduction of the Golgi apparatus and the number of microglia-neuron contacts has shown. High-resolution confocal images and three-dimensional rendering demonstrate that microglia engulf entire neurons at one-to-one ratio, and the microglial cell body participates in the formation of the phagocytic cup, engulfing and eliminating neurons in areas of dopaminergic degeneration in adult mammals