Le « Moustérien à denticulés » de la couche 20 de Combe-Grenal : implications techniques, économiques et fonctionnelles au sein du système de production Quina en Périgord

Le gisement de Combe-Grenal, célèbre pour son implication dans l’histoire de la recherche sur le Paléolithique moyen aquitain, offre une imposante séquence moustérienne contemporaine du Dernier Glaciaire (couches 1 à 37). Celle-ci se caractérise notamment par une série de couches attribuée au Moustérien de type Quina (couches 26 à 17), au sein de laquelle s’intercale la couche 20 attribuée par F. Bordes au Moustérien à denticulés. En apparence antinomique dans l’assise diachronique du Moustérien de type Quina, l’industrie de la couche 20 fait l’objet de cette contribution. Au regard des résultats obtenus, par le biais d’une démarche d’analyse mettant l’accent sur la caractérisation des modes de débitage et, surtout, sur la gestion des éclats (matrices), l’industrie de la couche 20 s’avère constituer un exemple singulier du potentiel techno-économico-fonctionnel offert par le système de production Quina.   

La fracturation en split, une technique de production dans l’industrie lithique des Tares (Sourzac, Dordogne)

A partir du ré-examen de l’industrie du gisement des Tares et d’une expérimentation, une description de la fracturation en split est proposée. Elle se caractérise par une percussion rentrante, sur appui plus ou moins ferme, de direction strictement verticale, avec des percuteurs présentant une touche rectiligne.Following a re-examination of the lithic industry from Les Tares (Dordogne), as well as an experimental study, we propose a description of split fractures. They are produced by vertical (orthogonal) blows from inside the nodule, which is either rested on the ground or handheld. The hammer is characterised by a linear striking surface

La fracturation en split, une technique de production dans l’industrie lithique des Tares (Sourzac, Dordogne)

A partir du ré-examen de l’industrie du gisement des Tares et d’une expérimentation, une description de la fracturation en split est proposée. Elle se caractérise par une percussion rentrante, sur appui plus ou moins ferme, de direction strictement verticale, avec des percuteurs présentant une touche rectiligne.Following a re-examination of the lithic industry from Les Tares (Dordogne), as well as an experimental study, we propose a description of split fractures. They are produced by vertical (orthogonal) blows from inside the nodule, which is either rested on the ground or handheld. The hammer is characterised by a linear striking surface

Molecular organization of the human serotonin transporter at the air/water interface

AbstractThe serotonin transporter (SERT) is the target of several important antidepressant and psychostimulant drugs. It has been shown that under defined conditions, the transporter spread at the air/water interface was able to bind its specific ligands. In this paper, the interfacial organization of the protein has been assessed from dynamic surface pressure and ellipsometric measurements. For areas comprising between 10 400 and 7100 Å2/molecule, ellipsometric measurements reveal an important change in the thickness of the SERT film. This change was attributed to the reorientation of the transporter molecules from a horizontal to their natural predictive transmembrane orientation. The thickness of the SERT film at 7100 Å2/molecule was found to be approximately equal to 84 Å and coincided well with the theoretical value estimated from the calculations based on the dimensions of α-helices containing membrane proteins. These data suggest that the three-dimensional arrangement of the SERT may be represented as a box with lengths dz=83–85 Å and dy or dx=41–47 Å

La grotte Castaigne (Commune de Torsac, Charente) : un site oublié riche en vestiges humains du Pléistocène

Au sein de PACEA, nous développons une dynamique scientifique sur la diversité techno-économique et les restes humains associés au Moustérien. En 2019-2020 nous avons ainsi entrepris la révision des collections de la grotte Castaigne (Torsac, Charente). Fouillée par L. Duport dans les années soixante, le matériel issu de ces recherches avait échappé à l’attention de la communauté malgré l’existence d’au moins deux néandertaliens différents identifiables dans les documents écrits. Nos recherch..

French Roadmap for complex Systems 2008-2009

This second issue of the French Complex Systems Roadmap is the outcome of the Entretiens de Cargese 2008, an interdisciplinary brainstorming session organized over one week in 2008, jointly by RNSC, ISC-PIF and IXXI. It capitalizes on the first roadmap and gathers contributions of more than 70 scientists from major French institutions. The aim of this roadmap is to foster the coordination of the complex systems community on focused topics and questions, as well as to present contributions and challenges in the complex systems sciences and complexity science to the public, political and industrial spheres

Prevalence of Grey Matter Pathology in Early Multiple Sclerosis Assessed by Magnetization Transfer Ratio Imaging

The aim of the study was to assess the prevalence, the distribution and the impact on disability of grey matter (GM) pathology in early multiple sclerosis. Eighty-eight patients with a clinically isolated syndrome with a high risk developing multiple sclerosis were included in the study. Forty-four healthy controls constituted the normative population. An optimized statistical mapping analysis was performed to compare each subject's GM Magnetization Transfer Ratio (MTR) imaging maps with those of the whole group of controls. The statistical threshold of significant GM MTR decrease was determined as the maximum p value (p<0.05 FDR) for which no significant cluster survived when comparing each control to the whole control population. Using this threshold, 51% of patients showed GM abnormalities compared to controls. Locally, 37% of patients presented abnormalities inside the limbic cortex, 34% in the temporal cortex, 32% in the deep grey matter, 30% in the cerebellum, 30% in the frontal cortex, 26% in the occipital cortex and 19% in the parietal cortex. Stepwise regression analysis evidenced significant association (p = 0.002) between EDSS and both GM pathology (p = 0.028) and T2 white matter lesions load (p = 0.019). In the present study, we evidenced that individual analysis of GM MTR map allowed demonstrating that GM pathology is highly heterogeneous across patients at the early stage of MS and partly underlies irreversible disability

Multifocal Ectopic Purkinje-Related Premature Contractions: A New SCN5A-Related Cardiac Channelopathy.: MEPPC: a new SCN5A-related cardiac channelopathy

International audienceOBJECTIVES: The aim of this study was to describe a new familial cardiac phenotype and to elucidate the electrophysiological mechanism responsible for the disease. BACKGROUND: Mutations in several genes encoding ion channels, especially SCN5A, have emerged as the basis for a variety of inherited cardiac arrhythmias. METHODS: Three unrelated families comprising 21 individuals affected by multifocal ectopic Purkinje-related premature contractions (MEPPC) characterized by narrow junctional and rare sinus beats competing with numerous premature ventricular contractions with right and/or left bundle branch block patterns were identified. RESULTS: Dilated cardiomyopathy was identified in 6 patients, atrial arrhythmias were detected in 9 patients, and sudden death was reported in 5 individuals. Invasive electrophysiological studies demonstrated that premature ventricular complexes originated from the Purkinje tissue. Hydroquinidine treatment dramatically decreased the number of premature ventricular complexes. It normalized the contractile function in 2 patients. All the affected subjects carried the c.665G>A transition in the SCN5A gene. Patch-clamp studies of resulting p.Arg222Gln (R222Q) Nav1.5 revealed a net gain of function of the sodium channel, leading, in silico, to incomplete repolarization in Purkinje cells responsible for premature ventricular action potentials. In vitro and in silico studies recapitulated the normalization of the ventricular action potentials in the presence of quinidine. CONCLUSIONS: A new SCN5A-related cardiac syndrome, MEPPC, was identified. The SCN5A mutation leads to a gain of function of the sodium channel responsible for hyperexcitability of the fascicular-Purkinje system. The MEPPC syndrome is responsive to hydroquinidine

Inhibition of Chondrosarcoma Growth by mTOR Inhibitor in an In Vivo Syngeneic Rat Model

BACKGROUND: Chondrosarcomas are the second most frequent primary malignant type of bone tumor. No effective systemic treatment has been identified in advanced or adjuvant phases for chondrosarcoma. The aim of the present study was to determine the antitumor effects of doxorubicin and everolimus, an mTOR inhibitor on chondrosarcoma progression. METHODS AND FINDINGS: Doxorubin and/or everolimus were tested in vivo as single agent or in combination in the rat orthotopic Schwarm chondrosarcoma model, in macroscopic phase, as well as with microscopic residual disease. Response to everolimus and/or doxorubicin was evaluated using chondrosarcoma volume evolution (MRI). Histological response was evaluated with % of tumor necrosis, tumor proliferation index, metabolism quantification analysis between the treated and control groups. Statistical analyses were performed using chi square, Fishers exact test. Doxorubicin single agent has no effect of tumor growth as compared to no treatment; conversely, everolimus single agent significantly inhibited tumor progression in macroscopic tumors with no synergistic additive effect with doxorubicin. Everolimus inhibited chondrosarcoma proliferation as evaluated by Ki67 expression did not induce the apoptosis of tumor cells; everolimus reduced Glut1 and 4EBP1 expression. Importantly when given in rats with microscopic residual diseases, in a pseudo neoadjuvant setting, following R1 resection of the implanted tumor, everolimus significantly delayed or prevented tumor recurrence. CONCLUSIONS: MTOR inhibitor everolimus blocks cell proliferation, Glut1 expression and HIF1a expression, and prevents in vivo chondrosarcoma tumor progression in both macroscopic and in adjuvant phase post R1 resection. Taken together, our preclinical data indicate that mTOR inhibitor may be effective as a single agent in treating chondrosarcoma patients. A clinical trial evaluating mTOr inhibitor as neo-adjuvant and adjuvant therapy in chondrosarcoma patients is being constructed