Correlation of messinian carbonate platforms

Esteban M., Clauzon Georges, Cornée Jean-Jacques, Cunningham K., Ferrandini Jean, Franseen E., Görür Naci, Guieu Gérard, Grasso M., Hôffling R., Meyers N., Muller J., Pedley Martyn, Plaziat J.-Cl., Suballyuva A., Suc Jean-Pierre, Valleri G., Van buchem Frans S. P. Correlation of messinian carbonate platforms. In: Géologie Méditerranéenne. Tome 21, numéro 1-2, 1994. Récifs et plates-formes carbonatées miocènes de Méditerranée / Miocene reefs and carbonate platforms of the Mediterranean. Interim colloquium R.C.M.N.S. (Marseille 3-6 mai 1994) sous la direction de Jean-Paul Saint-Martin et Jean-Jacques Cornée. pp. 159-163

Small mammal (rodents and lagomorphs) European biogeography from the Late Oligocene to the mid Pliocene

International audienceAim To analyse the fossil species assemblages of rodents and lagomorphs from the European Neogene in order to assess what factors control small mammal biogeography at a deep-time evolutionary time-scale. Location Western Europe: 626 fossil-bearing localities located within 31 regions and distributed among 18 successive biochronological units ranging from c . 27 Ma (million years ago; Late Oligocene) to c . 3 Ma (mid Pliocene). Methods Taxonomically homogenized pooled regional assemblages are compared using the Raup and Crick index of faunal similarity; then, the inferred similarity matrices are visualized as neighbour-joining trees and by projecting the statistically significant interregional similarities and dissimilarities onto palaeogeographical maps. The inferred biogeographical patterns are analysed and discussed in the light of known palaeogeographical and palaeoclimatic events. Results Successive time intervals with distinct biogeographical contexts are identified. Prior to c . 18 Ma (Late Oligocene and Early Miocene), a relative faunal homogeneity (high interregional connectivity) is observed all over Europe, a time when major geographical barriers and a weak climatic gradient are known. Then, from the beginning of the Middle Miocene onwards, the biogeography is marked by a significant decrease in interregional faunal affinities which matches a drastic global climatic degradation and leads, in the Late Miocene ( c . 11 Ma), to a marked latitudinal pattern of small mammal distribution. In spite of a short rehomogenization around the Miocene/Pliocene boundary (6–4 Ma), the biogeography of small mammals in the mid Pliocene ( c . 3 Ma) finally closely reflects the extant situation. Main conclusions The resulting biogeographical evolutionary scheme indicates that the extant endemic situation has deep historical roots corresponding to global tectonic and climatic events acting as primary drivers of long-term changes. The correlation of biogeographical events with climatic changes emphasizes the prevalent role of the climate over geography in generating heterogeneous biogeographical patterns at the continental scale

Development of a novel rat model with pancreatic fistula and the prevention of this complication using tissue-engineered myoblast sheets

Background: Pancreatic fistula (PF) is one of the most important complications of pancreatic surgery. The aims of this study were to establish a PF model in rats and to investigate the efficacy of our new method for preventing PF, which utilizes myoblast sheets made using tissue engineering techniques. Methods: To establish a PF model, the rats underwent transection of each of four pancreatic ducts: the gastric, duodenal, common, and splenic ducts, respectively. Their ascitic amylase and lipase levels were then measured. To investigate the efficacy of myoblast sheets at preventing PF, a myoblast sheet was attached to the pancreatic stump in the PF models. The levels of amylase and lipase in both serum and ascites were then measured, and surgical specimens were investigated pathologically. Results: The new PF model established by transecting the splenic duct in rats may prove very useful. There were no significant differences in serum amylase and lipase levels between the myoblast sheet (+) group and the sheet (-) group. However, there were significant differences in ascitic amylase and lipase levels between the two groups (p < 0.05). Among the pathological findings, the number of inflammatory cells in the myoblast sheet group was smaller than that in the control group. In addition, the presence of the myoblast sheets on the surface of the pancreatic stump was confirmed by immunofluorescence staining. Conclusion: Our data demonstrate the efficacy of the new rat model of PF presented herein, and that it might be possible to prevent PF using myoblast sheets