Nouvelles données sur les téphras pléistocènes piégés dans les remplissages karstiques ardéchois (SE France)

Des retombées volcaniques issues soit du Mont-Dore, soit du Vivarais ont été découvertes dans plusieurs sites karstiques de la BasseArdèche. Après celle d’Orgnac 3 liée au paroxysme terminal du Sancy autour de 0,3 Ma et celle de la Baume Moula issue, il y a 72 ± 12 ka, d’un maar appartenant au volcanisme Pléistocène supérieur de l’Ardèche, deux nouvelles retombées volcaniques ont été mises en évidence dans l’aven Marzal II. Dans la partie moyenne du remplissage, une association zircon – sphène est caractéristique d’un volcanisme différencié typique du MontDore, et pourrait être corrélée avec des émissions de pyroclastites situées vers 0,45 Ma. Dans la partie supérieure du remplissage, un autre type de retombée volcanique apparaît nettement avec des minéraux (olivine, orthopyroxènes, diopside, clinopyroxène brun) issus d’un volcanisme basaltique à enclaves mantelliques. Cette association est typique d’une retombée phréatomagmatique liée sans doute à l’éruption d’un maar du Vivarais. Les données biochronologiques et 14C la rattachent à la phase récente de ce volcanisme, entre 40 000 et 30 000 ans. Enfin, l’aven du Devès de Reynaud renferme un téphra d’origine phréatomagmatique, à relier probablement au volcanisme du Vivarais. Ces découvertes montrent l’intérêt du milieu karstique, favorable à la conservation de phénomènes dynamiques inconnus en surface.Volcanic ash-falls from Mont-Dore or Vivarais volcanoes have been discovered in different karstic sites of the “Basse-Ardèche” region. After the ash-fall of the Sancy volcano dated ca. 0.3 Ma described in Orgnac 3 aven and the ash-fall from an Upper Pleistocene Ardèche maar, 72 ± 12 ka ago, found in the Moula rock-shelter, two new tephra have been discovered in the Marzal II aven. The middle part of the filling includes a zircon-sphène association which is typical of a Mont-Dore differentiated volcanism and could be connected with pyroclastic outbursts ca. 0.45 Ma old. In the upper part of the filling, other minerals such as olivine, orthopyroxenes, diopside, brown clinopyroxene, correspond to a basaltic volcanism with mantellic enclaves. This association is typical of a phreatomagmatic ash-fall probably emitted by a maar in the Vivarais region. Biochronological and 14C data situate this latter tephra in the most recent phase of the Vivarais volcanism, between 40 - 30 ka. The Devès de Reynaud aven includes a third tephra also emitted during a phreatomagmatic event, probably due to the eruption of a Vivarais maar. These results show the interest of karstic fillings as they preserve the vestige of dynamic events today unknown on land surface

New geological and tephrochronological data on the palaeontological site of the Senèze maar (Early Pleistocene, Massif Central, France)

The volcanic system of Senèze (Domeyrat, Haute-Loire) comprises a basanite flow, scoriae, a maar crater and phreatomagmatic products. New field research and detailed cartography clarify their geometry and geological relationships. The maar contains an important palaeontological site of the Early Pleistocene that yielded forty species of mammals attributed to the biozone MNQ 18 (of which it is the reference locality). The excavations undertaken between 2001 and 2006 recovered new fossils and documented their stratigraphic and geodynamic context. The fossiliferous site is located on the shore of the palaeolake and includes several lacustrine and slope deposits linked to the contemporaneous climatic changes which in turn produced a number of locally fossiliferous findspots which appear to be close in age. The discovery of ten tephras emitted by the Mont-Dore strato-volcano, situated 60 km to the NW allowed development of a remarkable tephrochronological framework. Because of the intense weathering of the tephras, their composition is determined by their mineralogical content (feldspars, brown amphiboles, brown and green diopside, titanite, apatite, zircon, biotite-phlogopite, Fe-Ti oxides) and the chemical composition of feldspars (anorthoclase, sodic sanidine and plagioclases). The study of these tephras reveals the importance of the contemporaneous (mainly trachytic) pyroclastic activity and confirms the polyphased deposition of the site. The 40Ar/39Ar laser dating of alkali feldspars from five tephras shows a relatively narrow range of age comprised between 2.09 and 2.21 \textpm 0.02 Ma (1σ, age relative to ACs-2 standard at 1.201 Ma). Senèze is thus confirmed as a key Early Pleistocene palaeontological site in Europe

When were the walls of the Chauvet-Pont d'Arc Cave heated? A chronological approach by thermoluminescence

a b s t r a c t Direct chronological data of the ancient heating of calcitic walls at the Chauvet-Pont d'Arc Cave (Ard eche, France) were obtained at the Galerie des M egac eros and at the Eboulis d'Entr ee. Fragments of reddened limestone were extracted from the walls and were studied by thermoluminescence (TL). A novel measurement protocol of the equivalent dose (ED) was implemented and was optimized with respect to the nature of the material being dated (calcite), to the small quantities of sample available and to the relatively low heating of the rock surface in the past (close to 350 C). The presence of a high level of free radon in the cave and 210 Pb in large excess in samples implied the development of a specific irradiation model allowing the evaluation of the mean annual dose over time, taking into account possible scenarios of radon and daughters migration from the bedrock. The following dating results were obtained (in ka before the present and associated total estimated standard deviation): -Galerie des M egac eros, 36.9 ± 2.3 ka. -Eboulis d'Entr ee, 34.3 ± 2.9 ka. These data are in agreement with the calibrated radiocarbon dates of the most ancient periods of human occupation in their respective areas. TL dates indicate that the fires which altered the walls were lighted during the first paleolithic human occupation period. Eventually, TL dating of the heated surface of the bedrock opens a new window on the chronology of human activities in the Chauvet-Pont d'Arc Cave and it makes an alternative contribution to the demonstration of the early chronology of its rock art

Les parois chauffées de la grotte Chauvet-Pont d’Arc (Ardèche, France) : caractérisation et chronologie

Les recherches sur la taphonomie des parois ornées de la grotte Chauvet-Pont d’Arc ont conduit à l’identification et à l’étude détaillée de traces résultant d’un processus de chauffe : teintes rose et grise de la roche, écaillage et dépôts dus à la fumée. Ce faciès thermique a été observé aussi bien dans les premières salles, comportant majoritairement des peintures rouges, que dans les salles profondes où se trouvent la plupart des représentations réalisées au charbon de bois. Une étude paléothermométrique par thermoluminescence a été mise en œuvre sur des fragments de calcaire rubéfié collectés au sol ou sur les parois. Elle montre que la roche a été chauffée dans le passé à des températures comprises entre 300 et 375°C selon l’échantillon. Les données chronologiques, tant absolues (datation C14 des charbons) que relatives (relation avec les représentations pariétales) indiquent que les feux se rapportent principalement à l’Aurignacien. La fonction de ces feux reste inconnue : éclairage, ravivage de torche, production de colorant, ou encore de fumée ou de chaleur sans nécessité directe autre que symbolique, modification de l’état de surface de la paroi, protection vis-à-vis des ours qui fréquentaient la grotte en même temps que les hommes...Researches on the taphonomy of the rock art walls of the Chauvet-Pont d’Arc cave led to the identification and the detailed study of marks resulting from a heating process : pink and grey color of the rock, flakes due to the heat, and soot deposits. This thermal facies was observed in the first rooms, where the main red paintings are located, as well as in the deep rooms where most of the charcoal paintings were found. A paleothermometric study was undertaken by a thermoluminescence analysis of reddened limestone chips sampled on the archaeological floor or extracted from the walls. As a result, this study showed that the surface of the rock was heated in the past at temperatures ranging from 300 to 375°C according to the sample. The chronological data (C14 datings of the charcoals and relative chronology with the rock art) link the fires mostly to the Aurignacian. The function of the fires remains unknown : lighting, getting the torch going again, colourant production, smoke, heat production, without other reason than symbolic, modification of the wall state, protection from the bears who were present in the cave at the same period..

Internet of Things for enabling smart environments: a technology-centric perspective

The Internet of Things (IoT) is a computing paradigm whereby everyday life objects are augmented with computational and wireless communication capabilities, typically through the incorporation of resource-constrained devices including sensors and actuators, which enable their connection to the Internet. The IoT is seen as the key ingredient for the development of smart environments. Nevertheless, the current IoT ecosystem offers many alternative communication solutions with diverse performance characteristics. This situation presents a major challenge to identifying the most suitable IoT communication solution(s) for a particular smart environment. In this paper we consider the distinct requirements of key smart environments, namely the smart home, smart health, smart cities and smart factories, and relate them to current IoT communication solutions. Specifically, we describe the core characteristics of these smart environments and then proceed to provide a comprehensive survey of relevant IoT communication technologies and architectures. We conclude with our reflections on the crucial features of IoT solutions in this setting and a discussion of challenges that remain open for research

Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population

Le latin et la Réforme à Montbéliard, enseignement et imprimerie, XVIe-XVIIIe siècles

Debard Jean-Marc. Le latin et la Réforme à Montbéliard, enseignement et imprimerie, XVIe-XVIIIe siècles . In: Autour de Lactance : hommages à Pierre Monat. Besançon : Institut des Sciences et Techniques de l'Antiquité, 2003. pp. 235-248. (Collection « ISTA », 903

A André Thierry : Autour d’une amitié

Debard Jean-Marc. A André Thierry : Autour d’une amitié. In: Albineana, Cahiers d'Aubigné, 19, 2007. Lire l’Histoire Universelle pp. 11-15