Les concepts de base des Systèmes d’Information Géographique (SIG) : les données et les fonctions générales

La géomatique regroupe l'ensemble des outils et méthodes permettant d'acquérir, de représenter, d'analyser et d'intégrer les informations à référence spatiale issues de sources hétérogènes. Cette discipline, déjà largement développée au sein des unités de recherche devient de plus en plus couramment utilisée par les Unités Expérimentales de l’INRA, notamment par l’utilisation des systèmes d’informations géographiques (SIG). Dans cet article, nous revenons sur les bases nécessaires pour comprendre et utiliser un SIG. Un SIG permet de visualiser et d’analyser des données géographiques de deux formats principaux : le format raster (images satellites, photographies aériennes, cartes scannées, etc.) et le format vecteur qui correspond à une simplification du monde réel en objets graphiques auxquels sont reliées des informations descriptives plus ou moins complexes. Afin que toutes ces données soient superposables pour être analysées ensemble, elles doivent appartenir à un système de coordonnées ; c’est un système de référence permettant d’exprimer la position d’un objet dans ses deux ou trois dimensions. Toutes les données géographiques peuvent être regroupées en base des données spatialisées contenant toutes les informations essentielles pour une bonne utilisation (types de données utilisées, structure des données descriptives, source, date de création, etc.). Les fonctionnalités des SIG permettant l’exploitation des données géolocalisées (données issues de GPS, d'imageries satellitales, de photographies aériennes, de données d’expérimentation...) sont nombreuses. Les principales sont présentées à travers des exemples issus de problématiques rencontrées à l’INRA et sur le logiciels SIG Quantum Gis (QGis : logiciel libre et gratuit). L’utilisation des SIG ne serait pas optimisée sans une bonne qualité des données de référence. Nous dressons ainsi un panorama des données géographiques des grands producteurs de données français, accessibles gratuitement ou à faible coût au monde de la recherche publique depuis ces dernières années. La politique de l’Europe et de la France est de développer le partage de l’information géographique à l’aide des nouvelles technologies sur Internet, sur mobiles et lié au GPS. L’ensemble de ces éléments permet d’envisager une facilité d’accès et de partage à l’information spatialisée que l’on peut également mettre en place à l’INRA

Regulation of the Na,K-ATPase Gamma-Subunit FXYD2 by Runx1 and Ret Signaling in Normal and Injured Non-Peptidergic Nociceptive Sensory Neurons

Dorsal root ganglia (DRGs) contain the cell bodies of sensory neurons which relay nociceptive, thermoceptive, mechanoceptive and proprioceptive information from peripheral tissues toward the central nervous system. These neurons establish constant communication with their targets which insures correct maturation and functioning of the somato-sensory nervous system. Interfering with this two-way communication leads to cellular, electrophysiological and molecular modifications that can eventually cause neuropathic conditions. In this study we reveal that FXYD2, which encodes the gamma-subunit of the Na,K-ATPase reported so far to be mainly expressed in the kidney, is induced in the mouse DRGs at postnatal stages where it is restricted specifically to the TrkB-expressing mechanoceptive and Ret-positive/IB4-binding non-peptidergic nociceptive neurons. In non-peptidergic nociceptors, we show that the transcription factor Runx1 controls FXYD2 expression during the maturation of the somato-sensory system, partly through regulation of the tyrosine kinase receptor Ret. Moreover, Ret signaling maintains FXYD2 expression in adults as demonstrated by the axotomy-induced down-regulation of the gene that can be reverted by in vivo delivery of GDNF family ligands. Altogether, these results establish FXYD2 as a specific marker of defined sensory neuron subtypes and a new target of the Ret signaling pathway during normal maturation of the non-peptidergic nociceptive neurons and after sciatic nerve injury

Retail decline in France's small and medium-sized cities over four decades. Evidences from a multi-level analysis

International audienceIn recent years, a vast array of literature has shown that more and more city centres are affected by retail decline, be it in Japan, Belgium, Britain, the United States, or in France, while urban peripheries benefit from expanding retail activities. In this paper, we first rely on an international state of the art review, which allows us to identify recurring main factors that explain retail decline (such as sectoral concentration and competition from e-commerce), as well as more contextual factors bringing changes in urban settings and consumption practices (like demographic and labour market dynamics, the size of cities, or the location of municipalities within cities). Secondly, we examine how these factors, when combined, contribute to explain the decline in a superior diversity mix of retail activities in small and medium-sized French towns and cities, for four periods of about ten years each, from 1975 to 2014. The decline in shop diversity affects about a third of the municipalities observed in each period. Our hypotheses regarding the role of demographic size, employment mobility and location are then discussed and compared with the information given by the literature review

Perception of Gingival Bleeding by People and Healthcare Professionals: A Multicentre Study in an Adult French Population

International audienceGingival bleeding (GB) is a common sign of gingival inflammation, which indicates the presence of periodontal diseases. This study aimed to describe the perception of French adults about their self-reported GB and answers of healthcare professionals regarding the GB reported by these interviewees. A questionnaire administered by one investigator in each of three public settings of four cities in France from September 2016 to November 2017. Among 794 adults interviewed, 502 (63.2%) reported a GB. Among them, 414 (82.5%) believed that GB is benign, and 309 (61.6%) declared one or more responses. The three main responses were to use mouthwash (29.3%), to change to a soft-bristle toothbrush (20.1%) and to modify the brushing technique (19.3%). Almost half (49.0%) questioned at least one healthcare professional concerning their GB: a dentist (43.0%), a physician (14.1%), and a pharmacist (8.0%). The main response of each healthcare professional was: for dentists: a "prescription of mouthwash", for physicians to say "gingival bleeding is not serious"; and for pharmacists: "to sell a mouthwash". Most of the participants considered their GB as benign and had inappropriate responses, which indicates their lack of knowledge regarding periodontal health. The same conclusions can be drawn for healthcare professionals, as reported by interviewees

Drp1 Mediates Caspase-Independent Type III Cell Death in Normal and Leukemic Cells▿ †

Ligation of CD47 triggers caspase-independent programmed cell death (PCD) in normal and leukemic cells. Here, we characterize the morphological and biochemical features of this type of death and show that it displays the hallmarks of type III PCD. A molecular and biochemical approach has led us to identify a key mediator of this type of death, dynamin-related protein 1 (Drp1). CD47 ligation induces Drp1 translocation from cytosol to mitochondria, a process controlled by chymotrypsin-like serine proteases. Once in mitochondria, Drp1 provokes an impairment of the mitochondrial electron transport chain, which results in dissipation of mitochondrial transmembrane potential, reactive oxygen species generation, and a drop in ATP levels. Surprisingly, neither the activation of the most representative proapoptotic members of the Bcl-2 family, such as Bax or Bak, nor the release of apoptogenic proteins AIF (apoptosis-inducing factor), cytochrome c, endonuclease G (EndoG), Omi/HtrA2, or Smac/DIABLO from mitochondria to cytosol is observed. Responsiveness of cells to CD47 ligation increases following Drp1 overexpression, while Drp1 downregulation confers resistance to CD47-mediated death. Importantly, in B-cell chronic lymphocytic leukemia cells, mRNA levels of Drp1 strongly correlate with death sensitivity. Thus, this previously unknown mechanism controlling caspase-independent type III PCD may provide the basis for novel therapeutic approaches to overcome apoptotic avoidance in malignant cells

Caspase-independent type III programmed cell death in chronic lymphocytic leukemia: the key role of the F-actin cytoskeleton

Stimulation of the CD47 membrane receptor activates an original mechanism of cell death in chronic lymphocytic leukemia (CLL) cells that is caspase-independent. This study provides an exhaustive characterization of the CD47 anti-tumor signaling in CLL that may help to define new targets for further therapeutic strategies