Consulta: subjectFacets:"Biominéralisation"
Registros recuperados: 3
Data/hora: 11/06/2024 06:24:38

Caractérisation du comportement chimique du complexe otosac-otolithe et réaction à des perturbations induites.
Provedor de dados: 5
Autores: Edeyer, Anaick.
Teleost fish have the capacity to record in their otoliths, calcareous concretions located in the inner ear, the principal events (environmental and physiological) which punctuate their life. Otolith is made of CaC03 deposits on a protein matrix according to a circadian rhythm. Due to the quasi irreversibility of this process, otoliths can be compared to biological archives largely used to apprehend the fish ecology.   The otolith bathes in the endolymph, a medium in which all the precursors of otolith formation forward. The endolymph chemical analysis revealed a heterogeneity of its principal components (proteins, total C02 and total Ca) which origin lies in the non uniform spatial distribution of the ionocytes in the saccular epithelium. Thus, in...
Tipo: Text
Palavras-chave: Environmental disturbances; Microchemistry; Biomineralisation; Psetta maxima; Fish; Calcification; Endolymph; Otolith; Perturbations environnementales; Microchimie; Biominéralisation; Psetta maxima; Poisson; Calcification; Endolymphe; Otolithe.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/rapport-1123.pdf

Developmental aspects of biomineralisation in the Polynesian pearl oyster Pinctada margaritifera var. cumingii
Provedor de dados: 5
Autores: Che, Lm; Golubic, S; Le Campion-alsumard, T; Payri, C.
The shell biomineralisation with special reference to the nacreous region is observed during the development of the Polynesian pearl oyster. Ultrastructural changes were studied and timed for the first time from planktonic larval shells to two-year-old adult shells. During the first two weeks following fertilization, the prodissoconch-I shell structure is undifferentiated and uniformly granular. The prodissoconch-II stage which develops during the next two weeks acquires a columnar organization. Metamorphosis is characterized by the formation of the dissoconch shell with all the elements of an adult shell and marks the onset of the development of the nacre. Nucleation starts within an organic matrix from point sources forming 'crystal germs' which expand...
Tipo: Text
Palavras-chave: Biominéralisation; Couche nacrée; Huître perlière; Pinctada margaritifera; Polynésie française; Biomineralisation; Nacreous layer; Pearl oyster; Pinctada margaritifera; French Polynesia.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00291/40268/38642.pdf

La Biominéralisation de Pecten maximus L. : Anomalies liées aux Perturbations du Milieu
Provedor de dados: 5
Autores: Larvor, Helene.
L'étude du brunissement pathologique des valves de la coquille Saint-Jacques a permis d'identifier différents types d'altérations des mécanismes de la calcification : des détériorations microstructurales concomitantes avec une pigmentation brune anormale de la couche interne des tests. Les mécanismes de biominéralisation contrôlant l'intégration du carbonate de calcium dans les structures coquillières ne sont pas altérés : le taux de calcium, la minéralogie et la composition en acides aminés des matrices organiques cristallines sont équivalents dans les valves brunes et les valves blanches. Par contre, la présence d'une eumélanine, responsable de la coloration brune, est détectée dans les matrices organiques insolubles des régions coquillières aux...
Tipo: Text
Palavras-chave: Calcification; Coquille; Mélanine; Microstructure; Pecten maximus; Mollusques; Perturbations environnementales; Biominéralisation.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00043/15449/12823.pdf