Caractérisation thermique de foyers de l'âge du Bronze de la grotte des Fraux (Dordogne)

International audienceThe Les Fraux cave (Dordogne, France) was occupied during the Bronze Age. It contained numerous hearth features. The questions related to the function of the cave and more particularly of the hearth features involved a multidisciplinary study of these remains. The aim of this paper is to present the methods applied for the study of the hearths. The analysis combined thermoluminescence (TL) of the quartz grains and magnetic susceptibility principally registered by the iron oxides contained in the sediments (whether heated or not). For each sample, the TL permits to obtain the corresponding temperature (palaeotemperature) by comparison between the TL curves of the samples and those of the thermal references. The relationship established between the palaeotemperature and the magnetic susceptibility allows converting magnetic susceptibility to palaeotemperatures reached by the sediment on a larger surface. This permits to characterize the intensity of heat attained in these hearths and to contribute to the determination of the function of this site through the comparison with experimental firesLa grotte des Fraux (Dordogne, France), occupée à l'âge du Bronze, présente de nombreuses structures de combustion. Les questions relatives à la fonction du site et plus particulièrement des foyers, ont entrainé la mise en place d'une étude pluridisciplinaire de ces structures. L'objet de cet article est de présenter la méthodologie mise en oeuvre pour l'étude de ces foyers. Elle s'appuie sur un couplage entre la thermoluminescence (TL) des grains de quartz et la susceptibilité magnétique principalement portée par les oxydes de fer contenus dans les sédiments (chauffés ou non). Pour chaque prélèvement, la TL permet d'obtenir une température équivalente (paléotempérature) par comparaison entre les courbes TL correspondantes et celles de références thermiques. La relation établie entre la paléotempérature et la susceptibilité magnétique permet de traduire la carte de susceptibilité magnétique en paléotempératures atteintes par le sédiment sur une surface étendue. L'objectif est de caractériser l'intensité de chauffe de ces foyers et, par une comparaison avec des feux expérimentaux, de contribuer à préciser la fonction de ce site

Thermal characterization of ancient hearths from the cave of Les Fraux (Dordogne, France) by thermoluminescence and magnetic susceptibility measurements

International audienceNumerous sorts of evidence of fires were observed in the cave of Les Fraux (Dordogne, France) and in particular the effects of fire on sediment were studied for a better understanding of their use centuries ago. Our present objective is the evaluation of the firing intensity by determining the past temperature (paleotemperature) attained by the topmost sediment of the archaeological fires. The principle of paleotemperature determination is based on the thermoluminescence (TL) properties of quartz and the magnetic susceptibility of the sediment. By comparing the TL signal of anciently heated quartz to the TL signal of thermal references made in the laboratory, we were able to obtain a maximal equivalent temperature attained for each sample extracted from ancient fires. The magnetic susceptibility (previously measured on the hearth surface) could thus be estimated as a function of temperature. The main result of this study is the temperature mapping of the hearth which can be used as meaningful information about the ancient firing intensity

Conserved properties of genetic architecture of renal and fat transcriptomes in rat models of insulin resistance

To define renal molecular mechanisms that are affected by permanent hyperglycaemia and might promote phenotypes relevant to diabetic nephropathy, we carried out linkage analysis of genome-wide gene transcription in the kidneys of F2 offspring from the Goto-Kakizaki (GK) rat model of type 2 diabetes and normoglycaemic Brown Norway (BN) rats. We mapped 2526 statistically significant expression quantitative trait loci (eQTLs) in the cross. More than 40% of eQTLs mapped in the close vicinity of the linked transcripts, underlying possible cis-regulatory mechanisms of gene expression. We identified eQTL hotspots on chromosomes 5 and 9 regulating the expression of 80-165 genes, sex or cross direction effects, and enriched metabolic and immunological processes by segregating GK alleles. Comparative analysis with adipose tissue eQTLs in the same cross showed that 496 eQTLs, in addition to the top enriched biological pathways, are conserved in the two tissues. Extensive similarities in eQTLs mapped in the GK rat and in the spontaneously hypertensive rat (SHR) suggest a common aetiology of disease phenotypes common to the two strains, including insulin resistance, which is a prominent pathophysiological feature in both GK rats and SHRs. Our data shed light on shared and tissue-specific molecular mechanisms that might underlie aetiological aspects of insulin resistance in the context of spontaneously occurring hyperglycaemia and hypertension

Functional design method for improving safety and ergonomics of mechanical products

In order to help companies to improve their competetiveness, it is important to develop new design methodologies. In this framework, a Functional And Robust Design (FARD) methodology dedicated to routine design of “highly productive” modular product ranges is proposed including principles of functional analysis, Design For Assembly (DFA), and techniques of modelling and simulation for ergonomics consideration. This paper focuses on the application of this original method applied to mechanical vibration and ergonomics problems of a scraper. Including biomechanical aspect in the design methodology, it is possible to identify the impact of a vibration tool on its users using numerical models of the tool coupled to a finite element model of the human hand. This method can proactively warn very early, in the design process, the risks of causing musculoskeletal disorders and facilitate an optimization of the mechanical tool. This study is a first step in a context of human-centered design

Cursive Eye-Writing With Smooth-Pursuit Eye-Movement Is Possible in Subjects With Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder causing a progressive motor weakness of all voluntary muscles, whose progression challenges communication modalities such as handwriting or speech. The current study investigated whether ALS subjects can use Eye-On-Line (EOL), a novel eye-operated communication device allowing, after training, to voluntarily control smooth-pursuit eye-movements (SPEM) so as to eye-write in cursive. To that aim, ALS participants (n = 12) with preserved eye-movements but impaired handwriting were trained during six on-site visits. The primary outcome of the study was the recognition of eye-written digits (0–9) from ALS and healthy control subjects by naïve “readers.” Changes in oculomotor performance and the safety of EOL were also evaluated. At the end of the program, 69.4% of the eye-written digits from 11 ALS subjects were recognized by naïve readers, similar to the 67.3% found for eye-written digits from controls participants, with however, large inter-individual differences in both groups of “writers.” Training with EOL was associated with a transient fatigue leading one ALS subject to drop out the study at the fifth visit. Otherwise, itching eyes was the most common adverse event (3 subjects). This study shows that, despite the impact of ALS on the motor system, most ALS participants could improve their mastering of eye-movements, so as to produce recognizable eye-written digits, although the eye-traces sometimes needed smoothing to ease digit legibility from both ALS subjects and control participants. The capability to endogenously and voluntarily generate eye-traces using EOL brings a novel way to communicate for disabled individuals, allowing creative personal and emotional expression

The Implication of Early Chromatin Changes in X Chromosome Inactivation.

During development, the precise relationships between transcription and chromatin modifications often remain unclear. We use the X chromosome inactivation (XCI) paradigm to explore the implication of chromatin changes in gene silencing. Using female mouse embryonic stem cells, we initiate XCI by inducing Xist and then monitor the temporal changes in transcription and chromatin by allele-specific profiling. This reveals histone deacetylation and H2AK119 ubiquitination as the earliest chromatin alterations during XCI. We show that HDAC3 is pre-bound on the X chromosome and that, upon Xist coating, its activity is required for efficient gene silencing. We also reveal that first PRC1-associated H2AK119Ub and then PRC2-associated H3K27me3 accumulate initially at large intergenic domains that can then spread into genes only in the context of histone deacetylation and gene silencing. Our results reveal the hierarchy of chromatin events during the initiation of XCI and identify key roles for chromatin in the early steps of transcriptional silencing

Bast fibre formation: insights from Next-Generation Sequencing

Bast fibres are extraxylary sclerenchymatous cells characterized by a noteworthy length and by a cell wall composed of crystalline cellulose. Bast fibres support mechanically the phloem and are used for different industrial applications by the textile and biocomposite sectors. Fibre crops like hemp (Cannabis sativa), flax (Linum usitatissimum), ramie (Boehmeria nivea), jute (Corchorus olitorius, C. capsularis), kenaf (Hibiscus cannabinus) are therefore important natural resources which can help develop a sustainable economy. Despite the importance of bast fibres, not all the features related to their initiation and growth are fully explored and understood. In this review we will focus on the current knowledge concerning bast fibre initiation and development by using a transcriptomic angle, in the light of the great advances that Next-Generation Sequencing (NGS) has fostered in the last years. We discuss the results obtained recently on different fibre crops and we conclude our survey with a perspective on future molecular studies aimed at valorising neglected fibre crops, e.g. nettle (Urtica dioica)

Organic farmers’ reality to manage functional agrobiodiversity in European organic apple orchards

According to its principles and standards, organic farming particularly rely on natural processes and functional agro-biodiversity (FAB) to benefit from essential ecosystem services. However, these processes are mostly complex, hardly visible and site-specific, thereby making it difficult to assess and manage on-farm. A European survey has been carried out among organic farmers and emphasizes the variability among countries with a diversity of techniques targeting different functional groups according to farming contexts and farmers’ expectations. The different criteria used by farmers to evaluate FABtechniques efficiency and implementation potential clearly illustrate the difficulty to assess the agroecosystem as a whole

Focal plane wavefront sensing on SUBARU/SCExAO

Focal plane wavefront sensing is an elegant solution for wavefront sensing since near-focal images of any source taken by a detector show distortions in the presence of aberrations. Non-Common Path Aberrations and the Low Wind Effect both have the ability to limit the achievable contrast of the finest coronagraphs coupled with the best extreme adaptive optics systems. To correct for these aberrations, the Subaru Coronagraphic Extreme Adaptive Optics instrument hosts many focal plane wavefront sensors using detectors as close to the science detector as possible. We present seven of them and compare their implementation and efficiency on SCExAO. This work will be critical for wavefront sensing on next generation of extremely large telescopes that might present similar limitations

Organic farmers’ reality to manage functional agrobiodiversity in European organic apple orchards.

According to its principles and standards, organic farming particularly rely on natural processes and functional agro-biodiversity (FAB) to benefit from essential ecosystem services. However, these processes are mostly complex, hardly visible and site-specific, thereby making it difficult to assess and manage on-farm. A European survey has been carried out among organic farmers and emphasizes the variability among countries with a diversity of techniques targeting different functional groups according to farming contexts and farmers’ expectations. The different criteria used by farmers to evaluate FAB techniques efficiency and implementation potential clearly illustrate the difficulty to assess the agroecosystem as a whole