Les espaces de préparation alimentaire dans les <i>villae rusticae</i> de l’<i>ager pompeianus</i>

International audienceThanks to 18th century excavations and to rescue archaeology a small series of agricultural establishments on the territory of Pompeii is well documented. These villae, generally reburied after excavation, are only known indirectly, through the study of a few notes and archive documents. Often the topographical position and internal organisation of each villa can be identified. Areas dedicated to the preparation of food can be recognised from their construction and particular objects. On the other hand, we rarely have available comprehensive inventories, be they of pottery or of faunal remains. Multidisciplinary studies associating scientific analyses of objects with spaces have almost never been conducted. This accounts for the fact that the documentation and historiography on the kitchens of villae rusticae are entirely comparable with the knowledge available for Pompeian urban kitchens. These types of kitchens, however, are quite different in nature. By studying these food preparation areas we shall try to determine how their arrangement depends on the specific needs of each separate agricultural establishment.Grâce aux fouilles réalisées au XVIIIe s., puis à l’archéologie préventive, on connaît une petite série d’établissements agricoles dans le territoire pompéien. Généralement réensevelies après leur découverte, ces villae nous sont connues de façon indirecte, à travers l’étude des rares notices et des documents d’archives. Fréquemment, la position topographique de chaque villa et leur organisation interne nous sont connues. Les espaces de préparation culinaire sont identifiés grâce aux aménagements construits et à des objets particuliers. En revanche, il est rare que nous disposions d’inventaires complets, qu’il s’agisse des objets céramiques ou des restes fauniques. Les études pluridisciplinaires associant analyses scientifiques des objets et des espaces sont presque inexistantes. De cette façon, la documentation et l’historiographie des cuisines des villae rusticae sont en tout point comparables avec les connaissances disponibles sur les cuisines urbaines de Pompéi. Cependant ces aménagements diffèrent radicalement. En étudiant ces espaces de préparation culinaire, on tentera de déterminer de quelle manière leur organisation dépend des besoins propres aux différents établissements agricoles

Norbornadiene photoswitches anchored to well-defined oxide surfaces: From ultrahigh vacuum into the liquid and the electrochemical environment

Employing molecular photoswitches, we can combine solar energy conversion, storage, and release in an extremely simple single molecule system. In order to release the stored energy as electricity, the photoswitch has to interact with a semiconducting electrode surface. In this work, we explore a solar-energy-storing model system, consisting of a molecular photoswitch anchored to an atomically defined oxide surface in a liquid electrolyte and under potential control. Previously, this model system has been proven to be operational under ultrahigh vacuum (UHV) conditions. We used the tailor-made norbornadiene derivative 2-cyano-3-(4-carboxyphenyl)norbornadiene (CNBD) and characterized its photochemical and electrochemical properties in an organic electrolyte. Next, we assembled a monolayer of CNBD on a well-ordered Co3O4(111) surface by physical vapor deposition in UHV. This model interface was then transferred into the liquid electrolyte and investigated by photoelectrochemical infrared reflection absorption spectroscopy experiments. We demonstrate that the anchored monolayer of CNBD can be converted photochemically to its energy-rich counterpart 2-cyano-3-(4-carboxyphenyl)quadricyclane (CQC) under potential control. However, the reconversion potential of anchored CQC overlaps with the oxidation and decomposition potential of CNBD, which limits the electrochemically triggered reconversion

Ancestral bias in the Hras1 gene and distal Chromosome 7 among inbred mice

Inbred strains of mice vary in their frequency of liver tumors initiated by a mutation in the Hras1 (H-ras) proto-oncogene. We sequenced 4.5 kb of the Hras1 gene on distal Chr 7 in a diverse set of 12 commonly used laboratory inbred strains of mice and detected no sequence variation to account for strain-specific differences in Hras1 mutation prevalence. Furthermore, the Hras1 sequence is essentially monoallelic for an ancestral gene derived from the M. m. domesticus species. To determine if the monoallelism and associated low rate of polymorphism are unique to Hras1 or representative of the general chromosomal locale, we extended the sequence analysis to 12 genes in the final 8 Mb of distal Chr 7. A region of at least 2.5 Mb that encompasses several genes, including Hras1 and the H19/Igf2 loci, demonstrates virtually no sequence variation. The 12 inbred strains share one dominant haplotype derived from the M. m. domesticus allele. Chromosomal regions flanking the monoallelic segment exhibit a significantly higher rate of variation and multiple haplotypes, a majority of which are attributed to M. m. domesticus or M. m. musculus ancestry

Selective electrooxidation of 2-propanol on Pt nanoparticles supported on Co3O4: an in-situ study on atomically defined model systems

2-Propanol and its dehydrogenated counterpart acetone can be used as a rechargeable electrofuel. The concept involves selective oxidation of 2-propanol to acetone in a fuel cell coupled with reverse catalytic hydrogenation of acetone to 2-propanol in a closed cycle. We studied electrocatalytic oxidation of 2-propanol on complex model Pt/Co3O4(111) electrocatalysts prepared in ultra-high vacuum and characterized by scanning tunneling microscopy. The electrocatalytic behavior of the model electrocatalysts has been investigated in alkaline media (pH 10, phosphate buffer) by means of electrochemical infrared reflection absorption spectroscopy and ex-situ emersion synchrotron radiation photoelectron spectroscopy as a function of Pt particle size and compared with the electrocatalytic behavior of Pt(111) and pristine Co3O4(111) electrodes under similar conditions. We found that the Co3O4(111) film is inactive towards electrochemical oxidation of 2-propanol under the electrochemical conditions (0.3–1.1 VRHE). The electrochemical oxidation of 2-propanol readily occurs on Pt(111) yielding acetone at an onset potential of 0.4 VRHE. The reaction pathway does not involve CO but yields strongly adsorbed acetone species leading to a partial poisoning of the surface sites. On model Pt/Co3O4(111) electrocatalysts, we observed distinct metal support interactions and particle size effects associated with the charge transfer at the metal/oxide interface. We found that ultra-small Pt particles (around 1 nm and below) consist of partially oxidized Pt δ + species which show minor activity towards 2-propanol oxidation. In contrast, conventional Pt particles (particle size of a few nm) are mainly metallic and show high activity toward 2-propanol oxidation

Les espaces de préparation alimentaire dans les <i>villae rusticae</i> de l’<i>ager pompeianus</i>

International audienceThanks to 18th century excavations and to rescue archaeology a small series of agricultural establishments on the territory of Pompeii is well documented. These villae, generally reburied after excavation, are only known indirectly, through the study of a few notes and archive documents. Often the topographical position and internal organisation of each villa can be identified. Areas dedicated to the preparation of food can be recognised from their construction and particular objects. On the other hand, we rarely have available comprehensive inventories, be they of pottery or of faunal remains. Multidisciplinary studies associating scientific analyses of objects with spaces have almost never been conducted. This accounts for the fact that the documentation and historiography on the kitchens of villae rusticae are entirely comparable with the knowledge available for Pompeian urban kitchens. These types of kitchens, however, are quite different in nature. By studying these food preparation areas we shall try to determine how their arrangement depends on the specific needs of each separate agricultural establishment.Grâce aux fouilles réalisées au XVIIIe s., puis à l’archéologie préventive, on connaît une petite série d’établissements agricoles dans le territoire pompéien. Généralement réensevelies après leur découverte, ces villae nous sont connues de façon indirecte, à travers l’étude des rares notices et des documents d’archives. Fréquemment, la position topographique de chaque villa et leur organisation interne nous sont connues. Les espaces de préparation culinaire sont identifiés grâce aux aménagements construits et à des objets particuliers. En revanche, il est rare que nous disposions d’inventaires complets, qu’il s’agisse des objets céramiques ou des restes fauniques. Les études pluridisciplinaires associant analyses scientifiques des objets et des espaces sont presque inexistantes. De cette façon, la documentation et l’historiographie des cuisines des villae rusticae sont en tout point comparables avec les connaissances disponibles sur les cuisines urbaines de Pompéi. Cependant ces aménagements diffèrent radicalement. En étudiant ces espaces de préparation culinaire, on tentera de déterminer de quelle manière leur organisation dépend des besoins propres aux différents établissements agricoles