L'imaginaire urbain dans les régions ouvrières en reconversion: Le bassin stéphanois et le bassin minier du Nord Pas de Calais

Cette recherche est une recherche sociologique et anthropologique coordonnée par Michel Rautenberg rassemblant le Centre Max Weber de Saint-Étienne, le Centre Lillois d'études et de recherches sociologiques et économiques (sous la responsabilité du professeur Licia Valladarès) et l' Université de Sofia (sous la responsabilité du professeur Ivaylo Ditchev). Démarrée en décembre 2007 elle s'est terminée en avril 2011 et a bénéficié d'une aide de l'ANR de 180 k€ pour un montant global de 250 k€ de subventions publiques (non comprise une allocation de recherche).The general hypothesis at the origin of this research is that urban transformations do not go without social representations and the field of the imagination. It is essential for each image, word or story to be related to concrete situations that the researcher can describe. The choice of cities is thus not negligible. In this research programme, it has focussed on cities which have a had a difficult economic history characterised by brutal de-industrialization - more in people's minds than by its suddenness. This has left a traumatic effect on individual and collective memories, an urban landscape of industrial wasteland and 3 decades later it continues to strongly influence urban renovation policies. The first issue of this research, which in its second phase was extended to include Bulgarian cities thanks to the support of the Ministry for Foreign Affairs, was to establish a method making it possible to describe this imagination. So researchers agreed to work on imagination "operators", that is to say means (administrative, artistic or social) used by socially identified actors : artists, associations, inhabitants, former miners, municipal authorities. The second issue was to favour the imagination of cites which cannot be measured against communication strategies but which considers the "popular" social imagination which is sufficiently autonomous to exist outside municipal institutions - without asserting that it is completely independent. The third issue was to find common features in the comparison between situations close enough in their history to justify a pertinent comparison.L'hypothèse générale à l'origine de cette recherche est que les transformations urbaines ne font pas l'économie des représentations et des imaginaires sociaux. Il est donc nécessaire que chaque image, parole ou récit recueilli soit rapporté à des situations concrètes que le chercheur peut décrire. Le choix des villes n'est alors pas anodin. Dans ce programme de recherche, il s'est porté sur des villes qui ont eu une histoire économique difficile caractérisée par une désindustrialisation brutale -dans les esprits peut-être plus que par sa soudaineté. Celle ci a laissé des traumatismes dans les mémoires individuelles et collectives, un paysage urbain de friches industrielles, et continue après 3 décennies d'influencer fortement sur les politiques de rénovation urbaine

Inhibition of Wnt/β-Catenin Signaling by a Soluble Collagen-Derived Frizzled Domain Interacting with Wnt3a and the Receptors Frizzled 1 and 8

The Wnt/β-catenin pathway controls cell proliferation, death and differentiation. Several families of extracellular proteins can antagonize Wnt/β-catenin signaling, including the decoy receptors known as secreted frizzled related proteins (SFRPs), which have a cysteine-rich domain (CRD) structurally similar to the extracellular Wnt-binding domain of the frizzled receptors. SFRPs inhibit Wnt signaling by sequestering Wnts through the CRD or by forming inactive complexes with the frizzled receptors. Other endogenous molecules carrying frizzled CRDs inhibit Wnt signaling, such as V3Nter, which is proteolytically derived from the cell surface component collagen XVIII and contains a biologically active frizzled domain (FZC18) inhibiting in vivo cell proliferation and tumor growth in mice. We recently showed that FZC18 expressing cells deliver short-range signals to neighboring cells, decreasing their proliferation in vitro and in vivo through the Wnt/β-catenin signaling pathway. Here, using low concentrations of soluble FZC18 and Wnt3a, we show that they physically interact in a cell-free system. In addition, soluble FZC18 binds the frizzled 1 and 8 receptors' CRDs, reducing cell sensitivity to Wnt3a. Conversely, inhibition of Wnt/β-catenin signaling was partially rescued by the expression of full-length frizzled 1 and 8 receptors, but enhanced by the expression of a chimeric cell-membrane-tethered frizzled 8 CRD. Moreover, soluble, partially purified recombinant FZC18_CRD inhibited Wnt3a-induced β-catenin activation. Taken together, the data indicate that collagen XVIII-derived frizzled CRD shifts Wnt sensitivity of normal cells to a lower pitch and controls their growth

Human Endogenous Retrovirus Group E and Its Involvement in Diseases

International audienc

Simulation of pelvic mobility: topology optimisation of ligamentous system

International audienc

Pine wood retification : relationships between lignin structural alterations and wood performances.

International audienceRetification (thermal treatment of wood in an inert atmosphere between 200 and 260°C) noticeably increases both the wood resistance towards fungal degradation and the wood dimensional stability. To better understand the molecular basis of these improved performances, pine wood simples were retified in various conditions of severity. The structural alterations of lignins were investigated in relation with the wood properties. While very little change in lignin structure was observed when pine samples were treated under inert atmosphere up to 230°C, lignin structure was substantially altered when wood was heated 5 minutes at 240°C. These experimental conditions happen to correspond to those allowing to significantly improve pine wood dimensional stability and fungal resistance without detrimental loss of mechanical properties. When higher temperature (250°C) or longer thermal treatment (45 minutes) were applied to the pine samples further alteration of lignin structure, relative to the sample treated at 240°C for 5 minutes, occurred only to a moderate extent while the mechanical properties were dramatically reduced

Rétification du bois de pin maritime : impact sur la structure des lignines en relation avec les performances du bois matériau.

National audienceLa rétification du bois (traitement thermique sous atmosphère inerte entre 200 et 260°C) augmente la stabilité dimensionnelle et la résistance aux attaques fongiques de ce matériau. La compréhension des modifications de ces propriétés macroscopiques à l'échelle moléculaire est un préalable à l'utilisation raisonnée de la rétification. Dans ce but, les modifications induites au sein des lignines de bois de pin maritime ont été étudiées en relation avec les conditions expérimentales de la rétification et les performances du bois matériau. Si ces altérations sont très modérées jusqu'à 230°C, des modifications structurales importantes des lignines de pin surviennent lors du traitement du bois 5 minutes à 240°C, sous atmosphère inertes. Ces conditions correspondent précisément aux conditions de rétification permettant d'augmenter significativement la stabilité dimensionnelle et la résistance aux attaques fongiques du bois de pin sans altérer ses propriétés mécaniques de manière rédhibitoire. Au-delà de ce seuil expérimental, dans des conditions de thermolyse plus poussées (5 minutes à 250°C ou 45 minutes à 240°C), la structure des lignines évolue de manière moins accentuée tandis que les propriétés mécaniques du bois matériau s'effondrent

Isotopic and geochemical characterization of salinization in the shallow aquifers of a reclaimed subsiding zone: The southern Venice Lagoon coastland

The coastal plain bordering the southern Venice Lagoon is a reclaimed lowland characterized by high subsidence rate, and ground level and water-table depth below sea level. In this agricultural region, where the surface hydrologic network is entirely artificially controlled by irrigation/drainage canals, salinization problems have long been encountered in soils and groundwaters. Here we use isotopic and geochemical tracers to improve our understanding of the origin of salinization and mineralization of the semi-confined aquifer (0-40 m), and the freshwater inputs to this hydrological system. Water samples have been collected at different seasons in the coastal Adriatic Sea, lagoon, rivers and irrigation canals, as well as in the semi-confined aquifer at depths between 12 and 35 m (14 boreholes), and in the first confined aquifer (three boreholes drilled between 40 and 80 m depth). Stable isotopes (δ18O and δD) and conductivity profiles show that direct saline intrusion from the sea or the lagoon is observed only in a restricted coastal strip, while brackish groundwaters are found over the entire topographic and piezometric depression in the centre of the study area. Fresh groundwaters are found only in the most western zone. The sharp isotopic contrast between the western and central regions suggests disconnected hydrological circulations between these two parts of the shallow aquifer. The border between these two regions also corresponds to the limits of the most strongly subsiding zone. Our results can be interpreted in terms of a four end-member mixing scheme, involving (1) marine water from the lagoon or the open sea, (2) alpine and pre-alpine regional recharge waters carried either by the main rivers Adige, Bacchiglione and Brenta (irrigation waters) or by the regional groundwater circulation, (3) local precipitation, and (4) evaporated waters infiltrated from the surface. Infiltration from the surface is also revealed by the stratification of the electrical conductivity profiles, showing that the brackish groundwaters are overlain by a shallow layer of less saline water all over the central depression. In the first confined aquifer, the groundwaters have isotopic compositions similar to the deep groundwaters of the Venetian confined aquifers (40-400 m depth). The isotopic data and the Br/Cl ratio show that the origin of the salinization of the phreatic aquifer can be ascribed to seawater intrusion alone, with no indication of the involvement of deep brines (identified at 450 m depth) in the process. The chemical composition of the saline and brackish groundwaters is characterized by an excess of sodium and a deficit of calcium compared to conservative mixing between fresh groundwaters and seawater. This suggests that the phreatic aquifer is progressively freshening, as a consequence of the beneficial influence of the extensive irrigation/drainage network, including raised canals acting as a hydraulic barrier along the coast. This freshening tendency may have been lasting since the reclamation in the mid-twentieth century, and has probably been accelerated by the ban on groundwater abstraction since the 1970s

Submarine groundwater discharge in a subsiding coastal lowland: A Ra-226 and Rn-222 investigation in the Southern Venice lagoon

Several recent studies have suggested that submarine groundwater discharge (SGD) occurs in the Venice lagoon with discharge rates on the same order or larger than the surface runoff, as demonstrated previously in several other coastal zones around the world. Here, the first set of 222Rn data, along with new 226Ra data are reported, in order to investigate the occurrence and magnitude of SGD specifically in the southern basin of the lagoon. The independent connection with the Adriatic Sea (at the Chioggia inlet), in addition to the relative isolation of the water body from the main lagoon, make this area an interesting case study. There is probably only minimal fresh groundwater flux to the lagoon because the surrounding aquifer is subsiding and mainly has a lower hydraulic head than seawater. The data show that the Ra and Rn activities are in slight excess in the lagoon compared to the open sea, with values on the same order as those observed in the northern and central basins. Taking into account the water exchange rate between the lagoon and adjacent seawater provided by previous hydrodynamic numerical modelling, it is shown that this excess cannot be supported at steady state by only riverine input and by diffusive release from the sediment interstitial water. High activities observed in groundwater samples collected from 16 piezometers tapping into the shallow aquifer over the coastal lowland substantiate that the excess radioactivity in the lagoon may indeed be due to the advection of groundwater directly into the lagoon bottom water through the sediment interface. However, the data show that the groundwater composition is extremely heterogeneous, with high Ra activities concentrated within a narrow coastal strip where the contact between fresh and saline water takes place, while Rn strongly decreases when approaching the lagoon shore across the 20 km coastal plain. Assuming that the average groundwater activities measured in the coastal strip are representative of the SGD composition, a SGD flux of 7.7 ± 3.5 × 105 and 2.5 ± 2 × 106 m3/d is calculated using a 226Ra and 222Rn budget, respectively, (i.e. about 1-3 times the surface runoff), substantially lower than in previous studies. The influence of all assumptions on SGD estimates (groundwater heterogeneity, diffusive sediment flux, one-box versus multi-boxes model calculations) is discussed, and a sensitivity analysis of the influence of imperfect exchange and mixing at the lagoon outlets that affects the lagoon composition is provided. Finally, the results confirm that the SGD flux, calculated with these assumptions, is largely (∼80%) composed of saline lagoon water circulating through the sediment under the lagoon margin, and that the fresh water discharge associated with SGD is at most a minor term in the lagoon hydrologic balance

Improved leptin sensitivity as a potential candidate responsible for the spontaneous food restriction of the Lou/C rat.

The Lou/C rat, an inbred strain of Wistar origin, was described as a model of resistance to age- and diet-induced obesity. Although such a resistance involves many metabolic parameters described in our previous studies, Lou/C rats also exhibit a spontaneous food restriction due to decreased food consumption during the nocturnal period. We then attempted to delineate the leptin sensitivity and mechanisms implicated in this strain, using different protocols of acute central and peripheral leptin administration. A first analysis of the meal patterns revealed that Lou/C rats eat smaller meals, without any change in meal number compared to age-matched Wistar animals. Although the expression of the recognized leptin transporters (leptin receptors and megalin) measured in the choroid plexus was normal in Lou/C rats, the decreased triglyceridemia observed in these animals is compatible with an increased leptin transport across the blood brain barrier. Improved hypothalamic leptin signaling in Lou/C rats was also suggested by the higher pSTAT3/STAT3 (signal transducer and activator of transcription 3) ratio observed following acute peripheral leptin administration, as well as by the lower hypothalamic mRNA expression of the suppressor of cytokine signaling 3 (SOCS3), known to downregulate leptin signaling. To conclude, spontaneous hypophagia of Lou/C rats appears to be related to improved leptin sensitivity. The main mechanism underlying such a phenomenon consists in improved leptin signaling through the Ob-Rb leptin receptor isoform, which seems to consequently lead to overexpression of brain-derived neurotrophic factor (BDNF) and thyrotropin-releasing hormone (TRH)

Submarine groundwater discharge in a subsiding coastal lowland: A 226Ra and 222Rn investigation in the Southern Venice lagoon

Several recent studies have suggested that submarine groundwater discharge (SGD) occurs in the Venice lagoon with discharge rates on the same order or larger than the surface runoff, as demonstrated previously in several other coastal zones around the world. Here, the first set of 222Rn data, along with new 226Ra data are reported, in order to investigate the occurrence and magnitude of SGD specifically in the southern basin of the lagoon. The independent connection with the Adriatic Sea (at the Chioggia inlet), in addition to the relative isolation of the water body from the main lagoon, make this area an interesting case study. There is probably only minimal fresh groundwater flux to the lagoon because the surrounding aquifer is subsiding and mainly has a lower hydraulic head than seawater.The data show that the Ra and Rn activities are in slight excess in the lagoon compared to the open sea, with values on the same order as those observed in the northern and central basins. Taking into account the water exchange rate between the lagoon and adjacent seawater provided by previous hydrodynamic numerical modelling, it is shown that this excess cannot be supported at steady state by only riverine input and by diffusive release from the sediment interstitial water. High activities observed in groundwater samples collected from 16 piezometers tapping into the shallow aquifer over the coastal lowland substantiate that the excess radioactivity in the lagoon may indeed be due to the advection of groundwater directly into the lagoon bottom water through the sediment interface. However, the data show that the groundwater composition is extremely heterogeneous, with high Ra activities concentrated within a narrow coastal strip where the contact between fresh and saline water takes place, while Rn strongly decreases when approaching the lagoon shore across the 20 km coastal plain. Assuming that the average groundwater activities measured in the coastal strip are representative of the SGD composition, a SGD flux of 7.7 ± 3.5 × 105 and 2.5 ± 2 × 106 m3/d is calculated using a 226Ra and 222Rn budget, respectively, (i.e. about 1-3 times the surface runoff), substantially lower than in previous studies. The influence of all assumptions on SGD estimates (groundwater heterogeneity, diffusive sediment flux, one-box versus multi-boxes model calculations) is discussed, and a sensitivity analysis of the influence of imperfect exchange and mixing at the lagoon outlets that affects the lagoon composition is provided. Finally, the results confirm that the SGD flux, calculated with these assumptions, is largely (~80%) composed of saline lagoon water circulating through the sediment under the lagoon margin, and that the fresh water discharge associated with SGD is at most a minor term in the lagoon hydrologic balance