Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers

Publisher Copyright: © 2023, The Author(s).Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants.Peer reviewe

Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers

: Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants

Iminosugars-based macrocycles to deliver new sweet azacrowns

Les iminosucres, analogues de sucres dans lesquels l'oxygène endocyclique a été remplacé par un atome d'azote, constitue une classe importante de mimes de sucres. Aujourd'hui, leurs applications se limitent au domaine biologique car ces composés ont montré un potentiel thérapeutique prometteur. Il serait intéressant d'élargir le domaine d'application de ces iminosucres, et la combinaison de ces structures présentant un azote endocyclique pourrait conduire à de nouveaux macrocycles inédits présentant des propriétés de chélation innovantes. Pour cela, l'introduction d'une chaîne alkyle en position pseudoanomérique donne accès à une nouvelle classe de composés, les iminosucres C-glycosides dont la fonctionnalisation en positions C-5 et C-1 est nécessaire.La première partie de ce travail se focalise sur le développement d'une voie de synthèse rapide et efficace d'iminosucres C-glycosides à six et sept chaînons au moyen d'une réaction tandem de Staudinger aza-Wittig. Pour accéder à ces composés de choix, notre stratégie se base sur des réactions de fonctionnalisation diastéréosélectives et stéréocontrollées. La seconde partie de cette thèse a été consacrée à la synthèse d'iminosucres aza-couronnes, dont les structures constituent un nouveau type de récepteurs moléculaires. L'étude des propriétés de chélation de ces nouveaux macrocycles des cations métalliques a montré des premiers résultats prometteurs et encourageants grâce à des analyses par RMN et par fluorimétrie.Iminosugars, sugar analogs in which the endocyclic oxygen has been replaced by nitrogen, constitute a major class of sugar mimetics. Their application has been limited to the biological field so far as these compounds have shown promising therapeutic properties[1]. Interestingly, their structural analogy with sugars combined with the presence of an endocyclic nitrogen atom could deliver innovative macrocycles that could display chelation properties as well as catalytic potential when bound to metals and associated as duplex or higher multiplicity scaffolds. For this purpose, efficient introduction of an alkyl chain at the pseudoanomeric position of the iminosugar to yield an iminosugar C-glycoside[2] displaying two arms at C-5 and C-1 position is necessary. The first part of this work focused on the development of an efficient and convergent synthesis of seven and six membered iminosugars C-glycosides using a highly diastereoselective tandem Staudinger-Aza-Wittig reaction is presented. To access to these new compounds, our strategy is based on a highly diastereoselective and stereocontrolled functionalization. The second part of this work is based on the use of these structures to build up unprecedented iminosugar-aza-crowns, a new type of molecular receptors, using the strategy way developed in the first part. These news sweet aza-crowns displaying with various linkages showed promising results through their preliminary chelation properties by NMR and fluorimetric techniques

Improved quantification method of crocins in saffron extract using HPLC-DAD after qualification by HPLC-DAD-MS

International audienc

Nanocellulose-based materials for the reinforcement of modern canvas-supported paintings

The aim of this work was to evaluate the use of novel nanocellulose-based consolidants for modern easel paintings as a possible alternative to lining and to the use of common adhesives. Two dispersions of consolidants were tested: nanofibrillated (CNF) and nanocrystalline cellulose (CNC). A model cotton canvas was used to evaluate the effect of these consolidants following treatment by the nanocellulose-based formulations. The surface appearance of the canvases was assessed before and after treatment using colorimetry and scanning electron microscopy (SEM). Additionally, the characterisation of the mechanical properties of the samples was performed using tensile testing and dynamic mechanical analysis (DMA-RH) at controlled relative humidity (RH) (3 RH cycles, 20-60-20% RH at 25 °C) before and after treatment. Finally, colour changes undergone by the samples upon accelerated ageing were measured by colorimetry. Taking into account the individual outcomes of each of these tests, it was possible to evaluate the merits and limitations of the use of nanocellulose treatments for the consolidation of modern painting canvases

Safety Evaluation of a Sodium-Ion Cell: Assessment of Vent Gas Emissions under Thermal Runaway

International audienceNa-ion batteries are presented as a complementary technology to Li-ion batteries, that comply with the performance requirements of various applications without being submitted to the critical raw material dependencies pertaining to Li-ion batteries. Several major industrial actors are now committed to produce these batteries, advocating among others the safety gain of such technology. Available data on their behavior under thermal runaway are nonetheless very limited. This experimental work brings new elements of vent gas characteristics of Na-ion (Na3V2(PO4)2F3, NVPF) cells when thermally abused. A detailed gas analysis was performed in order to determine both composition of the gas mixture and related emitted volume. In our test configuration, no flames were observed, and the fumes were mainly composed of electrolyte compounds (organic carbonates). A simple comparison with Li-ion technology showed similarities with LiFePO4 (LFP) chemistries in terms of the nature and quantity of emitted gas

Evaluation of the adhesion and performance of natural consolidants for cotton canvas conservation

Recent developments in paper and canvas conservation have seen the introduction of nanocellulose (NC) as a compatible treatment for the consolidation of historical cellulosic artefacts and manuscripts. However, as part of the assessment of these new materials for canvas consolidation, the adhesion of the consolidation treatment (which takes place between the applied material and the substrate) has not yet been evaluated, and as a result, it is poorly understood by both the scientific and conservation communities. After evaluating the potential of NC treatments for the consolidation of cotton painting canvas, we investigate a route to promote the interaction between the existing canvas and the nanocellulose treatment, which is in our case made of cellulose nanofibrils (CNF). This was carried out by introducing a cationic polymer polyamidoamine-epichlorohydrin (PAAE) as an intermediate layer between the canvas and the CNF. The morphological, chemical and mechanical evaluation of the canvas samples at different relative humidity (RH) levels demonstrated how the adhesion of the added PAAE layer is a dominant factor in the consolidation process. Improvement in the coating of canvas single fibres by the CNF, higher adhesion energy between the canvas fibres and the CNF treatment and finally overall stronger canvas reinforcement were observed following the introduction of PAAE. However, an increase in mechanical response to moisture sorption and desorption was also observed for the PAAE-treated canvases. Overall, this study shows the complexity of such systems and, as such, the relevance of using a multi-scale approach for their assessment

Raman spectroscopy coupled to blind source separation methods for deformulation of surfactant mixtures

Raman spectroscopy coupled to blind source separation methods for deformulation of surfactant mixtures. Euroanalysis 18