Le silex du Flysch de Montgaillard et son exploitation sur les ateliers du Paléolithique supérieur à Hibarette (Hautes-Pyrénées)

Les auteurs présentent les résultats d’une étude portant sur le silex du flysch de Montgaillard et sur les ateliers de plein air paléolithiques de Hibarette (Hautes-Pyrénées) où il a été exploité. L’acquisition des données s’est faite par le biais d’une prospection systématique étalée sur une vingtaine d’années. La matière première a fait l’objet d’une caractérisation pétrographique et le contexte géomorphologique des gîtes exploités a pu être précisé.Les ateliers de taille ont fonctionné à toutes les périodes de la Préhistoire : Paléolithique moyen, supérieur et Néolithique. L’exploitation du silex au Paléolithique supérieur semble se placer surtout à l’Aurignacien, au Solutréen et au Magdalénien (ancien, moyen/supérieur). Néanmoins, il existe quelques indices de passages au Châtelperronien, au Gravettien ainsi qu’à l’Epipaléolithique. De par la qualité du silex, la masse de matière première qui a été débitée sur les ateliers de taille, et sa diffusion dans toutes les Pyrénées, le silex de Montgaillard/Hibarette tient une place de choix dans l’économie des matières siliceuses des Pyrénées centrales et les gîtes/ateliers de Hibarette sont certainement parmi les plus importants de cette région.The authors present the results of a study about both the flint of the Montagaillard flysch, but also about the Palaeolithic open air workshops in Hibarette (Hautes-Pyrénées) where the results have been analyzed. Data have been provided thanks to systematic surveys over twenty years. Raw material has been analyzed through a petrographical characterization and the geomorphological profile of the studied locations has been described as well. Knapping workshops have been used all though Prehistory time, that is to say Middle and Upper Palaeolithic, but also Neolithic.Flint production at Upper Palaeolithic time seems to correlate with Aurignacian, Solutrean and Magdalenian (Old, Middle and Upper). However, there are some pieces of evidence for an adequation with Chatelperronian, Gravettian and Epipalaeolithic.Thanks to the flint quality, the quantity of raw material removed in knapping workshops, and its presence overall in the Pyrénées, Montgaillard/Hirabette flint is very well positionned among siliceous materials trade of Central Pyrénées; flint workshops of Hirabette are certainly part of the most important ones in this area

Première note sur le Paléolithique inférieur de surface de la moyenne vallée de l'Arros (Hautes-Pyrénées)

Barragué Jean, Barragué T., Clot A., Marsan G. Première note sur le Paléolithique inférieur de surface de la moyenne vallée de l'Arros (Hautes-Pyrénées). In: Bulletin de la Société préhistorique française, tome 85, n°6, 1988. pp. 175-178

Mobilization of γδ T Cells and IL-10 Production at the Acute Phase of Hepatitis E Virus Infection in Cytomegalovirus Carriers

International audienceAlterations in the γδ T cell compartment have been reported in immunocompromised individuals infected with hepatitis E virus (HEV)–g3. We now report the analysis of blood γδ T cells from acutely HEV-infected individuals in the absence of immunosuppression. In these patients, non-Vδ2 (ND2) γδ T cells outnumbered otherwise predominant Vδ2 cells selectively in human CMV (HCMV)-seropositive patients and were higher than in HCMVpos controls, mimicking HCMV reactivation, whereas their serum was PCR-negative for HCMV. Stimulation of their lymphocytes with HEV-infected hepatocarcinoma cells led to an HEV-specific response in γδ subsets of HCMVpos individuals. HEV infection was associated with a lowered expression of TIGIT, LAG-3, and CD160 immune checkpoint markers on ND2 effector memory cells in HCMVneg but not in HCMVpos HEV patients. γδ cell lines, predominantly ND2, were generated from patients after coculture with hepatocarcinoma cells permissive to HEV and IL-2/12/18. Upon restimulation with HEV-infected or uninfected cells and selected cytokines, these cell lines produced IFN-γ and IL-10, the latter being induced by IL-12 in IFN-γ–producing cells and upregulated by HEV and IL-18. They were also capable of suppressing the proliferation of CD3/CD28–activated CD4 cells in transwell experiments. Importantly, IL-10 was detected in the plasma of 10 of 10 HCMVpos HEV patients but rarely in controls or HCMVneg HEV patients, implying that γδ cells are probably involved in IL-10 production at the acute phase of infection. Our data indicate that HEV mobilizes a pool of ND2 memory cells in HCMV carriers, promoting the development of an immunoregulatory environment

A multiple fine-scale satellite-derived landscape approach: example of bluetongue modelling in Corsica.

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Use of high spatial resolution satellite imagery to characterize landscapes at risk for bluetongue.

International audienceThe recent and rapid spread in the Mediterranean Basin of bluetongue, a viral disease of ruminants transmitted by some species of Culicoides (biting midges), highlights the necessity of determining the conditions of its emergence. This study uses high spatial resolution satellite imagery and methods from landscape ecology science to identify environmental parameters related to bluetongue occurrence in Corsica, a French Mediterranean island where the disease occurred for the first time in 2000. A set of environmental variables recorded in the neighborhood of 80 sheep farms were related to case occurrence through a logistic regression model computed within three subsequent buffer distances of 0.5, 1 and 2 km. The results reveal the role of landscape metrics, particularly those characterizing land-use units such as prairies and woodlands, as well as farm type, latitude and sunshine to explain the presence of bluetongue. Internal and external validation both indicate that the best results are obtained with the 1 km buffer size model (area under Receiver Operating Characteristic curve = 0.9 for internal validation and 0.81 for external validation). The results show that high spatial resolution remote sensing (i.e. 10 m pixels) and landscape ecology approaches contribute to improving the understanding of bluetongue epidemiology

The human occupation of the northwestern Pyrenees in the Late Glacial: New data from the Arudy basin, lower Ossau valley

International audienceExcavated since the 1860s, the Arudy basin has yielded a number of rich Magdalenian sites that enable us to address the question of the human reoccupation of the lower Pyrenean valleys at the end of the Last Glacial Maximum. Until the 1990s, it was considered that at Arudy this reoccupation started ca. 16,000 cal BP in the Middle Magdalenian and continued into the Upper Magdalenian until ca. 14,000 cal BP. However, since the mid-2000 s, this picture has been modified through a series of new analyses, excavations (caves of Laa 2 and Tastet), 14C dates and reassessment of ancient collections. Evidence of human occupation ca. 20,000–19,000 cal BP, although limited, has been identified at Laa 2 and Tastet, consistent with numerous data obtained at Pyrenean scale showing a deglaciation of the north Pyrenean foothills as early as the end of the global LGM. The number of sites with evidence of Magdalenian has increased, showing that human presence in the basin was more intensive than previously thought. The Middle and Upper Magdalenian occupations have been redated to at least 18,000–17,500 cal BP to 15,000–14,500 cal BP, with the transition between the two phases probably occurring ca. 16,600–16,200 cal BP. The faunal records of these sites document an emphasis on horse hunting, which is not common in the northern Pyrenees, but also witness an evolution over time in the range of species hunted. Furthermore, the Pyrenean affinities of the Arudy groups and their relations with neighboring regions, such as Spain and the northern part of the Aquitaine basin, can be addressed through new evidence: in particular lithic and osseous raw materials and specific types of projectile tips. These results significantly change our view of the nature, rhythm and chronology of the Late Glacial settlement in this area