A study of the roman half-products of Saintes-Maries-de-la-Mer (Bouches-du-Rhône, France). A proposal for a comprehensive metallographic approach

téléchargeable sur: http://www.sciencedirect.com/science/article/pii/S0305440311000021International audienceThe aim of this paper is to contribute to the understanding of the organisation of the manufacture and circulation of iron bars and the possible bar standardisation of a given set of artefacts in order to throw more light on commercial patterns during Antiquity. A set of 48 iron based metal bars originating from the Roman shipwrecks at Les Saintes-Maries-de-la-Mer (France) has been studied using comprehensive metallographic observations, ranging from macroscopic to microscopic scales and slag inclusion (SI) analyses. A comparison of the results allows one to distinguish different metal qualities (inclusions, pores, welding, carbon content) that may be linked to morphological types, which shows the possible standardisation of this set of artefacts. Moreover, SI analyses allow distinguishing various origins for the Primary Pieces of Metal, thereby throwing light on a specific organisation of the iron bar production line during the late Roman period

The multidisciplinary approach (archaeology and archaeometry) to bloomsmithing activities in France: examples of results from the last twenty years

Over the last twenty years, archaeological and archaeometrical research implemented in France has made it possible to define the various stages of the chaîne opératoire in iron and steelmaking as well as the indicators that are linked to them (archaeological structures, wastes). These studies reveal that the chaîne opératoire may (or may not) split in space and time, but may also contain varying degrees of intensity (mini-maxi production). This implies that the production sites can be from different natures: they may include partial or complete chaîne opératoire, and are part of a social context (e.g., rural, urban, specialized, or domestic craft). The relationships within the chaîne opératoire create links between the sites and form a technological, economic, and social network through trade in semi-finished and manufactured products. The evolution of these networks must be studied by taking into account the cultural and political contexts of each period to draw up a coherent understanding of this organization. The determination of site activities (smelting, refining, elaboration, consumption, recycling), as well as intensity, allow a dynamic cartography of these activities, both synchronic and diachronic, to be realized. The physicochemical linkages between the ore, the smelting slag, the post-smelting slag, and the metal produced make possible an eventual understanding of the connection between sites that are part of the same exchange network. This in turn reflects the regional development of metallurgical organization and the trade in iron semi-products and manufactured goods. The typological attribution (morphology, level of impurities, iron/carbon composition, phosphorus contents, etc) of semi-products worked on the forging sites also makes it possible to refine the vision of what circulate and of what the sites acquire. Thus, an archaeological and historical study of these data can structure the relative image we have of these relations in the various periods

An archaeological and archaeometrical approach of ferrous semi-product : a diachronic qualitative typology (VIIth c. BC. - IInd c. A.D.)

From the raw bloom to the final product, depending on the nature of the latter, several semiproducts can be obtained along the chaîne opératoire. Some of them are directly transformed on the ironmaking site. Some other, on the contrary are marketed between several workshops, production centres or markets. On relation with the quantity of work to obtain them, or with the quality of the constituting material, they could have different values. For these reasons, understanding the way these semi-products were obtained and in which technico-economical context, but also the way they were comprehended by the ancient craftsmen and blacksmith is a fundamental aspect of ironmaking technical and economical history, whatever the period under interest is. The aim of the general overview presented here is to review, from the archaeological site to the laboratory, the different clues that allow to enlighten several aspects linked to the semi-product production and exchanges. Indeed, even if the archaeometric observations are scientific facts, they can never be considerate out of any archaeological and historical context. Thus, a constant come and go must be undertaken between the physico-chemical data and this context. For example, as far as the metal quality is concerned, added to the fact that numerous parameters will influence the mechanical behaviour of the material, it is important to know that it is not the only aspect that will determine the use of a given material. It is merely a more complex conjunction of its quality, the skill of the blacksmith, the availability of the metals in the technico-economical context under study, etc. Depending on the place in the chaîne opératoire, semi products can be more or less elaborated and of different natures: bloom slightly hammered after a first compaction treatment, ingot obtained after a more important hammering and cleansing, currency and socket bars, with a thinner shape closer to the form of the final artefact, etc. Semi-products can question several aspects of archaeological and historical studies. At the archaeological site level, it is of great interest to understand the spatial and technical organisation of the site, and sometimes of different production sites in the same area and period. It is also important to evaluate the nature of the forging sequences, the type of activities and production and the quantities. Another crucial question is the nature of the metal that is produced and marketed, linked to his mechanical behaviour, and the value it has in the different technicoeconomical contexts. To study this point it is necessary to try to evaluate it by identifying the parameters that mainly influence this quality and trying to define reproducible study methodologies in order to compare the different artefacts. Then, another important point is to study the semi-product diffusion and exchange on more or less long distances. To this purpose, crucial chemical data can be found in the slag inclusions (SI) embedded in the metallic artefact, that offers the possibility to identify homogeneous or heterogeneous corpuses but also, in specific cases, to enlighten the production region of the artefacts. Our research for 10 years concerns an important number of sites and artefacts covering periods from the 1st iron age to medieval times. Following the methodology of former works made in east of France and in the Swiss Jura, in the frame of several PhD works, we significantly completed our pluridisciplinary and diachronic investigations on the French territory for the following areas: Grande Limagne d'Auvergne, Nord du Bassin parisien, Narbonnaise (Languedoc-Roussillon, Provence-Alpes-Côte-d'Azur), Normandy, Pays de Bray, Pyrénées ariégeoises and an important part of central Burgundy. More than 600 ironmaking, sites, tens of historical buildings and several hundred artefacts were studied. These works allowed us to precisely define the internal characteristics of the materials in order to evaluate on the one hand the real nature of the forging activities on given sites, on the other hand the qualitative criteria that could help to identify some specificities and follow exchanges and technical breaks

Le travail du fer dans l'établissement perché tardo-antique du Roc de Pampelune (Argelliers, Hérault) : l'apport des analyses métallographiques

Le site perché du Roc de Pampelune occupe, de la fin du Ve siècle au milieu du VIe siècle, un plateau calcaire dans la garrigue nord montpelliéraine (Hérault, France) sur un peu plus de deux hectares. Depuis 1999, sa fouille a livré plus de 5400 scories (soit environ 109 kg) et de nombreuses structures métallurgiques qui ont motivé un examen approfondi pour localiser les espaces de travail et préciser le type d'activité. Une lecture croisée liant analyses archéologiques et métallographiques a donc été réalisée afin de déterminer le rôle et la place de la métallurgie au sein de cet établissement. Ainsi, est mise en évidence, à côté du rôle administratif, l'importance économique de ces habitats perchés dans la réorganisation du réseau de peuplement des campagnes gauloises au cours du premier Moyen Age.The hill-top site of the “Roc de Pampelune” occupies, from the end of the Vth century A.D. to the middle of the VIth century, a limestone plateau in the ilex oak forests north of Montpellier (Hérault, France) covering an area over two hectares. Since 1999, the excavation of this site has produced more than 5400 fragments of slag (amounting to 109 kg) and many metallurgical structures which have led to extensive research in order to pinpoint work areas and to establish the kind of production. Conjoint archaeological and metallographie analyses have been conducted in order to determine the part and place of metallurgy in this settlement. This way, we have underlined the economic importance as well as the administrative part of these hill-top sites in the reorganisation of the settlement pattern of the gaulish countryside during the first phase of the Middle-Ages

In Vivo Evolution of Bacterial Resistance in Two Cases of Enterobacter aerogenes Infections during Treatment with Imipenem

International audienceInfections caused by multidrug resistant (MDR) bacteria are a major concern worldwide. Changes in membrane permeability, including decreased influx and/or increased efflux of antibiotics, are known as key contributors of bacterial MDR. Therefore, it is of critical importance to understand molecular mechanisms that link membrane permeability to MDR in order to design new antimicrobial strategies. In this work, we describe genotype-phenotype correlations in Enterobacter aerogenes, a clinically problematic and antibiotic resistant bacterium. To do this, series of clinical isolates have been periodically collected from two patients during chemotherapy with imipenem. The isolates exhibited different levels of resistance towards multiple classes of antibiotics, consistently with the presence or the absence of porins and efflux pumps. Transport assays were used to characterize membrane permeability defects. Simultaneous genome-wide analysis allowed the identification of putative mutations responsible for MDR. The genome of the imipenem-susceptible isolate G7 was sequenced to closure and used as a reference for comparative genomics. This approach uncovered several loci that were specifically mutated in MDR isolates and whose products are known to control membrane permeability. These were omp35 and omp36, encoding the two major porins; rob, encoding a global AraC-type transcriptional activator; cpxA, phoQ and pmrB, encoding sensor kinases of the CpxRA, PhoPQ and PmrAB two-component regulatory systems, respectively. This report provides a comprehensive analysis of membrane alterations relative to mutational steps in the evolution of MDR of a recognized nosocomial pathogen

Особенности ценообразования на рынке экскурсионных услуг Крыма

Цель статьи – анализ специфики ценообразования на экскурсионные услуги в Крыму как важного фактора развития этого рынка