The Burgundian « visage ». Seals between tradition and innovation

Les grandes étapes de l’histoire du royaume de Bourgogne ainsi que les transformations que ce royaume subit pendant près de cent vingt ans se reflètent dans plusieurs sources, notamment dans les sceaux. Ces derniers permettent, en autres, d’en comprendre l’orientation politique. C’est le cas, par exemple, de Rodolphe Ier qui tient énormément à s’inscrire dans la continuité des Carolingiens de la Francia orientalis pour renforcer sa légitimité et consolider son règne. Par ailleurs, de nombreuses évolutions se lisent dans les sceaux, oscillants entre traditions et innovations, comme lorsque Rodolphe II tente d’agrandir le royaume en focalisant son attention sur la Souabe et sur le regnum Italiae, puis lors de la fusion de la Transjurane et du royaume de Provence sous Conrad et, enfin, au moment où les Ottoniens étendent leur emprise sur Rodolphe III

Introduction

Évoquer la « Bourgogne », c’est mettre l’eau à la bouche des gourmets et des gourmands qui commencent à rêver du Kir, du Nuits-Saint-Georges, du Vosne-Romanée, du coq au vin, de la moutarde dijonnaise et des repas si délicieux préparés à la bourguignonne. Pour l’historien de l’art, c’est songer à Cluny, Tournus, Paray-le-Monial ou Autun, s’extasier au vu des œuvres de Rogier van der Weyden, de Jan van Eyck ou de Claus Sluter. Et qu’en est-il de ceux qui s’intéressent à l’histoire médiévale ? ..

Biofilm Formation by Listeria monocytogenes 15G01, a Persistent Isolate from a Seafood-Processing Plant, Is Influenced by Inactivation of Multiple Genes Belonging to Different Functional Groups

Listeria monocytogenes is a ubiquitous foodborne pathogen that results in a high rate of mortality in sensitive and immunocompromised people. Contamination of food with L. monocytogenes is thought to occur during food processing, most often as a result of the pathogen producing a biofilm that persists in the environment and acting as the source for subsequent dispersal of cells onto food. A survey of seafoodprocessing plants in New Zealand identified the persistent strain 15G01, which has a high capacity to form biofilms. In this study, a transposon library of L. monocytogenes 15G01 was screened for mutants with altered biofilm formation, assessed by a crystal violet assay, to identify genes involved in biofilm formation. This screen identified 36 transposants that showed a significant change in biofilm formation compared to the wild type. The insertion sites were in 27 genes, 20 of which led to decreased biofilm formation and seven to an increase. Two insertions were in intergenic regions. Annotation of the genes suggested that they are involved in diverse cellular processes, including stress response, autolysis, transporter systems, and cell wall/membrane synthesis. Analysis of the biofilms produced by the transposants using scanning electron microscopy and fluorescence microscopy showed notable differences in the structure of the biofilms compared to the wild type. In particular, inactivation of uvrB and mltD produced coccoid-shaped cells and elongated cells in long chains, respectively, and the mgtB mutant produced a unique biofilm with a sandwich structure which was reversed to the wild-type level upon magnesium addition. The mltD transposant was successfully complemented with the wild-type gene, whereas the phenotypes were not or only partially restored for the remaining mutants. IMPORTANCE The major source of contamination of food with Listeria monocytogenes is thought to be due to biofilm formation and/or persistence in food-processing plants. By establishing as a biofilm, L. monocytogenes cells become harder to eradicate due to their increased resistance to environmental threats. Understanding the genes involved in biofilm formation and their influence on biofilm structure will help identify new ways to eliminate harmful biofilms in food processing environments. To date, multiple genes have been identified as being involved in biofilm formation by L. monocytogenes; however, the exact mechanism remains unclear. This study identified four genes associated with biofilm formation by a persistent strain. Extensive microscopic analysis illustrated the effect of the disruption of mgtB, clsA, uvrB, and mltD and the influence of magnesium on the biofilm structure. The results strongly suggest an involvement in biofilm formation for the four genes and provide a basis for further studies to analyze gene regulation to assess the specific role of these biofilm-associated genes.Peer reviewe

Nowak, Jessika (Historisches Seminar, Albert-Ludwigs-Universität Freiburg)

Name/Nom: Nowak Vorname/Prénom: Jessika Titel/Fonction: Dr. Universität/Université: Albert-Ludwigs-Universität Freiburg Forschungseinrichtung/Institution de recherche: Lehrstuhl für Mittelalterliche Geschichte I Email/Couriel: [email protected] Adresse/Adresse: Werthmannstraße 8, D-79085 Freiburg Homepage/Site internet: http://www.mittelalter1.uni-freiburg.de/personal/nowak Social Networks/Réseaux sociaux (academia, facebook, twitter etc.): ‎Gewünschte Kooperationen/Coo..

Fighting with words and swords – Italian diplomacy during the long quattrocento

Sorgfältig gewählte Worte können Konflikte durchaus entschärfen und einhegen. Sie müssen dabei nicht zwangsläufig beschwichtigend sein, sondern können auch (fiktive) Drohszenarien aufbauen und bewusst darauf ausgelegt sein, den Gegner einzuschüchtern. Die Federn der diplomatischen Akteure konnten spitz sein und flott deren Mundwerke, harte Kämpfe konnten dementsprechend auch mit diesen Waffen ausgefochten werden. Sicherlich nicht ohne Grund sollte der Mailänder Herzog Giangaleazzo betonen, er fürchte einen einzigen von Coluccio Salutatis Briefen weit mehr als tausend feindliche Reiter (211). ..