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Nombre de programmes trouvés : 1642
Séminaires

le (45m20s)

Vectorisation de plans anciens et apprentissage profond (deep learning)

Joseph Chazalon, Maître de conférence, EPITACette présentation dresse un bilan provisoire des travaux menés dans le cadre du projet ANR SODUCO. Ce projet vise à analyser l’évolution morphologique de la ville de Paris entre 1789 et 1950 au travers du suivi des déplacements des activités socio-économiques. Un volet important concerne la rétro-conversion d’atlas municipaux au 1/5000e de la ville de Paris permettant de reconstituer la structure de la ville et en particulier son réseau de voirie, avec le nom des voies. Nous présentons ici nos premiers résultats permettant d’accélérer de façon significative le travail de vectorisation des plans en couplant ...
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Séminaires

le (32m43s)

Développements géomatiques pour la reconstruction spatio-temporelle des paysages : application en écologie historique

Pierre-Alexis Herrault, Maître de conférence, Université de Strasbourg.Présentation de deux applications de traitements spatiaux ayant pour objectif d'observer la passé. L'une concerne l'extraction automatisée de données à partir de la carte d'Etat-Major de 1850. La seconde concerne la colorisation de photographie aériennes anciennes issus de travaux de thèse de Quentin Poterek.
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Conférences

le (20m6s)

Dr Frédéric Marin - Mollusk shell matrices: unexpected functions in biomineralization

To construct their skeletons, all metazoans secrete a complex array of macromolecules that are supposed to display key-functions in biomineralization, such as crystal nucleation and crystal growth orientation. These macromolecules - generally less than 1% of the skeletal weight - are occluded during skeletal growth and can be retrieved and analyzed by dissolving the mineral phase. They comprise proteins, glycoproteins, peptides, polysaccharides, and sometimes, lipids, pigments and metabolites. They constitute collectively the 'calcifying matrix', from which proteins and glycoproteins are the most studied. In the last decade, the coupling of high-throughput ...
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Conférences

le (19m35s)

Dr Sophie Berland - Probing the mechanical properties and biochemical defence offered by shell matrix proteins in bivalves

Calcium carbonate is paired up with shell matrix proteins in the suited organo-mineral outer shell in molluscs. Advanced knowledge in the shell proteome is achieved with the development of proteomics providing insights in the biological control of biomineralization at the shell side. Four bivalve species of distant kinship were subjected to proteomics for sequence and function pattern analysis of their retrieved shell matrix proteins. Domains ruling for calcification mechanisms, e.g. carbonic anhydrase, chitin binding and tyrosinase remained common in all the species signing sustained calcifying control proteins. Other shell proteins were fitted ...
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Conférences

le (19m2s)

Dr Christine Paillard - The Brown Ring disease in clams, a double-edged defense mechanism for shell disease recovery!

Brown Ring disease is caused by Vibrio tapetis, which, by adhering to newly secreted shell matrices, interferes with the biomineralization process. Colonization and alteration of the matrices induce the deposit of conchiolin on the inner surface of the valves, forming a characteristic brown deposit instead of contributing to shell growth. This defense mechanism consists firstly in coating the bacteria within the organic layers of melanized matrices, and secondly in covering the brown deposit with shell layers to achieve complete healing of the shell. This defense phenotype varies greatly depending on, (1) the ...
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Conférences

le (22m38s)

Dr Robbie Rae - Biological armour used to kill parasites

The co-evolution of parasites and hosts has shaped the immune system. One such ‘arms race’ is between parasitic nematodes and their molluscan hosts. One such species (Phasmarhabditis hermaphrodita) can infect and kill several gastropod species and has been formulated into a biological control agent (Nemaslug®) for farmers and gardeners. In order to defend themselves from P. hermaphrodita infection we have recently found that several snail species encapsulate and kill nematodes by producing unknown cells which fuse them to the inner part of the shell. This is a rapid process occurring over 48 ...
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Conférences

le (33m0s)

Prof. Bernd Kaspers - The developing immune system of the chicken embryo

Development of hematopoietic cells has been investigated intensively in the chicken embryo. Early hematopoietic stem cells develop in the aortic region and seed to primary lymphoid organs where they mature into T- and B-lymphocytes. Subsequently, they start to colonize the periphery at embryonic day 15/19 and around hatch, respectively. Monoclonal antibodies, recombinant cytokines and new in vivo technologies were instrumental to dissect these pathways. For example, bursal development is dependent on B cell activating factor of the TNF family (BAFF) as shown by retroviral mediated overexpression of BAFF or its decoy receptor ...
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Conférences

le (29m52s)

Prof. Marc McKee - The structure of avian (chicken) eggshell

The functional properties of biomineralized structures found in Nature result from interactions between their hybrid components – both organic (mostly proteins) and inorganic (mineral) phases – to generate hierarchical organization across different length scales. In its dual function, the calcitic avian eggshell provides a protective barrier for the enclosed developing chick embryo while also serving to provide calcium for the growing chick skeleton by the process of shell dissolution. Here, a detailed structural analysis (including a description of nanostructure) is given for the eggshell produced by the domesticated chicken, along ...
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Conférences

le (15m38s)

Prof. Alejandro Rodriguez Navarro - Mechanisms of eggshell biomineralization

The avian eggshell is a thin mineral layer (350 µm thick in chicken) that protects the egg content against mechanical impacts, dehydration and microorganism contamination. Eggshell formation is a highly controlled and rapid mineralization process occurring while the egg is residing in the uterus during the night. The composition of the uterine fluid changes at each stage of eggshell formation (initiation, linear growth, termination) with the expression of specific proteins that actively regulate calcium carbonate precipitation, selecting the mineral phase to form (calcite), inducing the nucleation of crystals and controlling ...
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