Parallelized 3D optical flow method for fluid mechanics applications

International audienceIn this paper we address the problem of estimating the motion of fluids in 3D image sequences. We present a 3D extension of the second order div-curl regularization 2D optical flow equation first introduced by Corpetti et al.. In addition, we propose a multigrid and Message Passing Interface (MPI) parallelized implementation of the algorithm to handle the huge amount of data encountered in our applications. The performance of the resulting fluid flow estimator is demonstrated on a well representative motion synthetic pattern called Hill's spherical vortex. The suggested method should be a good alternative or complement to the well established techniques based on 3D cross correlation

L'exploitation des matériaux colorants au Paléolithique supérieur. Quelles stratégies d'approvisionnements, quelles transformations pour quelles utilisations ?

Peer reviewe

Exploitation of beehive products, plant exudates and tars in Corsica during the early Iron Age

International audienceIn the northwestern Mediterranean area, the first Iron Age is characterized by intense contacts and cultural interactions between populations. Archaeological remains such as ceramic vessels or metal and glass objects are usually good indicators of the nature and the intensity of these exchanges, but can also be used to determine the way in which these populations were living at their time. In contrast, organic substances, despite their importance in a wide variety of activities, are rarely investigated due to their low degree of preservation. The recent discovery of a series of amorphous organic residues with adhesive properties at the site of Cuciurpula provided a unique opportunity to address questions related to the types of natural substances exploited, their provenance, their uses and their informational input to intercultural relationships. Our results, based on GC and GC–MS analysis of organic residues preserved at the site of Cuciurpula, provide strong evidence for the most southern use of birch bark tar in Western Europe, and also for the simultaneous use of this substance with pine resin. Beeswax was also identified in some samples. The combined study of residue composition, aspect and location on ceramic sherds reveals a variety of uses, highlighting a complex technical system

Analytical strategies for discriminating archaeological fatty substances from animal origin

International audienceMass spectrometry (MS) is an essential tool in the field of biomolecular archeology to characterize amorphous organic residues preserved in ancient ceramic vessels. Animal fats of various nature and origin, namely subcutaneous fats of cattle, sheep, goats, pigs, horses, and also of dairy products, are those most commonly identified in organic residues in archeological pottery. Fats and oils of marine origin have also been revealed. Since the first applications of MS coupled with gas chromatography (GC) in archeology at the end of 1980s, several developments have occurred, including isotopic determinations by GC coupled to isotope ratio MS and identification of triacylglycerols (TAGs) structure by soft ionization techniques (ESI and APCI). The combination of these methods provides invaluable insights into the strategies of exploitation of animal products in prehistory. In this review, I focus on the analytical strategies based upon MS that allow elucidation of the structure of biomolecular constituents and determination of their isotopic values to identify the nature of animal fat components preserved in highly complex and degraded archeological matrices.

Red Lustrous Wheelmade ware: analysis of organic residues in Late Bronze Age trade and storage vessels from the eastern Mediterranean

YesTransport and storage vessels in Red Lustrous Wheelmade ware (RLWm ware) were traded across a large area of the eastern Mediterranean for approximately 300 years (c. 1500–1200 BCE) during the Late Bronze Age (c.1600–1000 BCE). The extreme consistency of the ceramic, in form, fabric, chemistry and mineralogy, points to a single production source for the ware, which, although no kiln sites have been identified, is generally accepted to have been on Cyprus. The aim of this study was to determine whether organic residues were present in this very fine, dense ware, and to characterise the contents of RLWm ware vessels from different sites, contexts and periods, and of different forms, to improve our understanding of the trade in this ceramic type. To that end, 101 RLWm ware sherds, together with three visible residues, were examined from sites in Turkey, Cyprus, Egypt and Syria. Residues were identified in more than half of the samples, indicating that organic material is absorbed into and preserved in this very fine fabric. Four commodities were identified: fat (probably plant oil), which in four residues was identified further as castor oil; beeswax; bitumen; and Pinaceae spp. resin. The commodities were found alone or, occasionally, one of the latter three was combined with the fat or oil. Fatty material was the only commodity present at all sites and its wide distribution may indicate that generally the vessels were used for a mixture or mixtures based on plant oils, in some cases containing castor oil. It was impossible to determine whether the beeswax, bitumen and resin formed part of this mixture or represented post-firing treatments of the ceramic to make it less porous. The identification of more than one type of residue indicates that RLWm ware vessels did not always contain the same commodity. No significant correlation could be detected between the vessel forms, and the dating of many of the sherds was not precise enough to reveal any variation through time. The type of residue present did vary depending on the geographical location of its final use. Beeswax was, with two exceptions, only present in samples from Turkey, while bitumen was found exclusively in samples from Cypriot sites. The occurrence of at least one example of every commodity in the samples from Cyprus is consistent with the theory that this ware was manufactured on Cyprus, and indicates that the vessels could also have been filled and exported from there. The variation in content of the vessels found in different geographical areas could highlight a special trading relationship between the Hittite heartland in Turkey and the Cypriot potters who produced the ware, and a possible trade in bitumen as a raw material between the north Syrian coastal area of Ugarit and Cyprus.This research was funded by an AHRC PhD studentship (number 110786), awarded to V. Steele

The analysis of European lacquer : optimization of thermochemolysis temperature of natural resins

In order to optimize chromatographic analysis of European lacquer, thermochemolysis temperature was evaluated for the analysis of natural resins. Five main ingredients of lacquer were studied: sandarac, mastic, colophony, Manila copal and Congo copal. For each, five temperature programs were tested: four fixed temperatures (350, 480, 550, 650 degrees C) and one ultrafast thermal desorption (UFD), in which the temperature rises from 350 to 660 degrees C in 1 min. In total, the integrated signals of 27 molecules, partially characterizing the five resins, were monitored to compare the different methods. A compromise between detection of compounds released at low temperatures and compounds formed at high temperatures was searched. 650 degrees C is too high for both groups, 350 degrees C is best for the first, and 550 degrees C for the second. Fixed temperatures of 480 degrees C or UFD proved to be a consensus in order to detect most marker molecules. UFD was slightly better for the molecules released at low temperatures, while 480 degrees C showed best compounds formed at high temperatures

O papel da Educação alimentar e nutricional no ambiente escolar

A Educação Alimentar e Nutricional (EAN), é uma importante estratégia para prevenção e controle de problemas alimentares e nutricionais da atualidade. Nessa perspectiva, o ambiente escolar é apontado por diversos autores como um espaço ideal para a execução dessas ações e que para o seu sucesso devem consistir em processos ativos, lúdicos e interativos, favorecendo, assim, a construção do conhecimento, autonomia e auxiliando nas mudanças de atitudes. O presente artigo trata-se de pesquisa bibliográfica, realizada por meio de consulta em bases de dados de relevância para a produção de conhecimento em saúde e nutrição e tem como objetivo realizar uma reflexão sobre o papel da EAN, com enfoque no âmbito escolar, visando contribuir para um melhor entendimento do assunto, possibilitando uma discussão sobre as fragilidades e potencialidades das metodologias e estratégias utilizadas nas suas ações. É necessário ampliar a pauta e a visão sobre a EAN e desenvolver novos instrumentos teóricos e metodológicos que abordem todas as dimensões da complexidade desse processo. No âmbito do Programa Nacional de Alimentação Escolar – PNAE, a EAN, com a oferta de alimentos são as principais estratégias para garantir a Segurança Alimentar e Nutricional e promover o Direito Humano à Alimentação Adequada aos estudantes da rede pública de ensino. Para isso, se faz necessário aprofundar a discussão sobre o papel da EAN no ambiente escolar, investindo na formação dos profissionais envolvidos, no desenvolvimento de metodologias, incentivar pesquisas científicas na temática. Acredita-se que dessa forma, conseguiríamos melhores resultados referente as mudanças positivas das práticas alimentares dos alunos, assim como a comunidade escolar

Foodstuffs and organic products in ancient south-east Arabia

Exchange networks in the Bronze Age between south-east Arabia, Mesopotamia, south-east Iran, south-west Pakistan, and the Indus Valley moved a variety of raw and finished products, especially pottery. However, we have little understanding of what organic products were a part of these exchange networks, as well as what foodstuffs were prepared in ceramic vessels as part of everyday activities. This paper presents the preliminary results of lipid residue analysis of local and imported vessels from Hili 8 and Hili North Tomb A in al-Ain, United Arab Emirates (UAE). Absorbed lipids were extracted and analysed via gas chromatography-mass spectrometry (GC-MS) from a range of vessels including local, regional, Indus, Mesopotamian, and Makran wares. A majority of the lipid profiles were indicative of degraded animal fats, although some vessels, including Fine Red Omani Ware and imported Black-Slipped Jars from the Indus Valley, had evidence of plant oils. Further analyses that will shed light on the possible origin of the animal fats and plant oils are ongoing. The preliminary results provide new insights into the use of pottery at Hili, with broader implications for our understanding of subsistence and exchange networks in the region