Compte rendu du colloque international autour de Edgar Morin

Les « 4èmes rencontres de socio-anthropologie de Grenoble », organisées par le laboratoire emc2-lsg – Université Pierre Mendès‑France sous la direction de Florent Gaudez, avaient cette année pour invité d’honneur Edgar Morin, fondateur de la « pensée complexe », dont il expose les principes dans son œuvre majeure qu’est La méthode (2008). Une vaste pensée qui, sous l’œil attentif et vif de son auteur, a été approchée au travers de quatre thématiques de séance, évoquant certaines préoccupation..

Phenotypic variation in dorsal fin morphology of coastal bottlenose dolphins (Tursiops truncatus) off Mexico

Geographic variation in external morphology is thought to reflect an interplay between genotype and the environment. Morphological variation has been well-described for a number of cetacean species, including the bottlenose dolphin (Tursiops truncatus). In this study we analyzed dorsal fin morphometric variation in coastal bottlenose dolphins to search for geographic patterns at different spatial scales. A total of 533 dorsal fin images from 19 available photo-identification catalogs across the three Mexican oceanic regions (Pacific Ocean n = 6, Gulf of California n = 6 and, Gulf of Mexico n = 7) were used in the analysis. Eleven fin shape measurements were analyzed to evaluate fin polymorphism through multivariate tests. Principal Component Analysis on log-transformed standardized ratios explained 94% of the variance. Canonical Discriminant Function Analysis on factor scores showed separation among most study areas (p < 0.05) with exception of the Gulf of Mexico where a strong morphometric cline was found. Possible explanations for the observed differences are related to environmental, biological and evolutionary processes. Shape distinction between dorsal fins from the Pacific and those from the Gulf of California were consistent with previously reported differences in skull morphometrics and genetics. Although the functional advantages of dorsal fin shape remains to be assessed, it is not unlikely that over a wide range of environments, fin shape may represent a trade-off among thermoregulatory capacity, hydrodynamic performance and the swimming/hunting behavior of the species

Role of the Si/Al molar ratio and pH in NIW/MCM41-Al2O3 catalysts for HDS of DBT

This research presents a series of catalytic supports of MCM41 modified with γ-Al2O3 with a Si/Al molar ratio of 10, 25 and 50. These materials were impregnated with Ni + W solutions at pH 7 and pH 9, respectively and were evaluated in the hydrodesulfurization (HDS) of dibenzothiophene (DBT) reaction. In order to modify the low acidity of MCM41, its surface acidity was modified by incorporation of alumina content in the supports. The sol–gel incorporation method of Al2O3 to the structure of the MCM41 did produce changes in the characteristic of hexagonal arrangement of mesoporous materials. The symmetries of the materials were determined through UV–vis where the octahedral and tetrahedral nickel species were found. By Raman, monotungstate (WO4) and polytunsgtate (W12O408−) species were observed. The HDS of DBT showed that in the NiW/AMS50 catalyst impregnated at pH 9 presents the highest reaction rate. And in the case of the catalysts impregnated at pH 7 the highest reaction rate was achieved by the NiW/AMS10 catalyst. The selectivity was mainly oriented to the production of biphenyl (BP). The low catalytic activity was attributable to low formation NiWS species responsible for the HDS activity

Synthesis, characterization and catalytic properties of NiMoP/MCM41-Al2O3 catalysts for DBT hydrodesulfurization

NiMoP/MCM41-γAl2O3 (NiMoP/AMx) supported catalysts have been investigated as a modification of MCM41 by using the sol–gel alumina incorporation method. Different catalysts were synthesized varying the Si/Al molar ratio (5, 10, 25 and 50). The aqueous solution method was used to impregnate the metallic species (NiMoP) on the AMx supports. A surface area high mesoporous solid was synthesized by using an organic template method. The incorporation of sol–gel alumina did modified the hexagonal array of the mesoporous material MCM41 when the preparation of AMx supports was carried out. The XRD patterns of the catalytic supports show that phases, MCM-41 and γ-Al2O3 exist, indicating the presence of the two materials in the synthesized solids. Raman spectroscopy also indicates the formation of NiMoO4 and MoO3 which are more difficult to sulfide and produce MoS2 and Ni3S2 as separated sulfides instead of the NiMoS phase. The symmetries of the materials were determined through UV–vis where octahedral NiO as well as tetrahedral and octahedral Mo were found. The main reaction products were biphenyl (BP), cyclohexylbenzene (CHB) and bicyclohexyl (BCH) when the materials were tested in the HDS of DBT