Search results for "MINERALS"
showing 10 items of 247 documents
Molecular modularity and asymmetry of the molluscan mantle revealed by a gene expression atlas
2018
15 pages; International audience; Background: Conchiferan molluscs construct a biocalcified shell that likely supported much of their evolutionary success.However, beyond broad proteomic and transcriptomic surveys of molluscan shells and the shell-forming mantle tissue,little is known of the spatial and ontogenetic regulation of shell fabrication. In addition, most efforts have been focused onspecies that deposit nacre, which is at odds with the majority of conchiferan species that fabricate shells using acrossed-lamellar microstructure, sensu lato. Results: By combining proteomic and transcriptomic sequencing with in situhybridization we have identified a suite of gene products associated …
The skeleton of the staghorn coral Acropora millepora: molecular and structural characterization.
2014
15 pages; International audience; The scleractinian coral Acropora millepora is one of the most studied species from the Great Barrier Reef. This species has been used to understand evolutionary, immune and developmental processes in cnidarians. It has also been subject of several ecological studies in order to elucidate reef responses to environmental changes such as temperature rise and ocean acidification (OA). In these contexts, several nucleic acid resources were made available. When combined to a recent proteomic analysis of the coral skeletal organic matrix (SOM), they enabled the identification of several skeletal matrix proteins, making A. millepora into an emerging model for biomi…
The test skeletal matrix of the black sea urchin Arbacia lixula
2015
11 pages; International audience; In the field of biomineralization, the past decade has been marked by the increasing use of high throughput techniques, i.e. proteomics, for identifying in one shot the protein content of complex macromolecular mixtures extracted from mineralized tissues. Although crowned with success, this approach has been restricted so far to a limited set of key-organisms, such as the purple sea urchin Strongylocentrotus purpuratus, the pearl oyster or the abalone, leaving in the shadow non-model organisms. As a consequence, it is still unknown to what extent the calcifying repertoire varies, from group to group, at high (phylum, class), median (order, family) or low (g…
Nanoparticles and their influence on radionuclide mobility in deep geological formations
2012
International audience; This article gives an overview of the current status of knowledge concerning the role of nanoparticles (inorganic and organic) in deep geological host rocks and the potential influence of these nanoparticles on radionuclide migration in far-field systems. The manuscript is not intended to be a full review paper or overview paper concerning nanoparticles, here the intention is to refer to recent publications but to highlight the progress made in the 6th framework project IP FUNMIG (Fundamental processes of radionuclide migration) and the open literature over the past 5 a concerning the process understanding of nanoparticle related issues in the three host rock formati…
Chemical variations in clay minerals of the Archaean Barberton Greenstone Belt (South Africa)
1996
Abstract Four rock profiles of shales, carbonates and greywacke-type sediments were sampled from the mafic compositional influenced sedimentary Fig Tree Group and from overlying, more felsic related, sedimentary Moodies Group of the Archaean Barberton Greenstone Belt in South Africa. Clay separates of forty sedimentary rocks were examined by XRD and SEM to study the mineralogical, chemical and morphological variations of the constitutive illite and chlorite. The clay minerals showed a significant K-enrichment in the illites and Mg- and Fe-depletions in the chlorites upwards the stratigraphic sequence. Three independent parameters influenced these variations: (1) a change in the origin of th…
Structure-related geochemical (REE) and isotopic (K-Ar, Rb-Sr, δ18O) characteristics of clay minerals from Rotliegend sandstone reservoirs (Permian, …
1999
Abstract Euhedral illite cementing the gas-bearing sandstone reservoirs of the Rotliegend in the Niedersachsische rift system (northern Germany) was studied along a horst-to-graben cross-section to examine its chemical and isotopic characteristics. The data show that differentiated illite particles grew during a tectono-thermal event marked by distinct episodic hydrothermal activities along fault drains and in the poral space of sandstones at 210 Ma and at 195 to 190 Ma in horst positions, at 185 to 175 Ma in the nearby graben, and at 170 to 165 Ma in both the horst and graben. Varied REE distribution patterns and initial 87Sr/86Sr ratios (from 0.7124 to 0.7142) relative to illite-particle …
Burial and thermal evolution of the Sicilian fold-and-thrust belt: preliminary results from the Scillato wedge top basin (central-northern Sicily, It…
2016
Wedge top basins are key elements for unravelling the tectonic evolution of fold-and-thrust belts. In detail, their thermal signature and sedimentary fill records modes and time of exhumation of their edges. The Scillato basin is a wedge-top basin located in the central-northern sector of the Sicilian fold-and-thrust belt (western sector of the Madonie Mts). Upper Serravallian-upper Tortonian succession composed by up to 1,200 m thick delta-river to open marine siliciclastic sediments, fills the basin. This succession lies on a deformed substrate made up of thrust sheets composed of Numidian Flysch, Sicilidi and Imerese units stacked with a SW tectonic transport. The basin fill records a po…
Mineralogical and chemical variability of fluvial sediments: 1. Bedload sand (Ganga–Brahmaputra, Bangladesh)
2010
This study investigates the natural processes that control concentration of detrital minerals and consequently chemical elements in river sand. The novelty of our approach consists in the systematic integration of detailed textural, petrographical, mineralogical and chemical data, and in the quantitative description and modeling of relationships among mineralogical and chemical variables for each sample and each grain-size class in each sample. Bed sediment in transit in the largest sedimentary system on Earth chiefly consists of fine-grained lithofeldspatho quartzose sand including rich amphibole–epidote–garnet suites, mixed with minor very-fine grained-sand to silt subpopulations containi…
Acidic Monosaccharides become Incorporated into Calcite Single Crystals*.
2020
Streptococcus suis is an encapsulated bacterium and one of the most important swine pathogens and a zoonotic agent for which no effective vaccine exists. Bacterial capsular polysaccharides (CPSs) are poorly immunogenic, but anti-CPS antibodies are essential to the host defense against encapsulated bacteria. In addition to the previously known serotypes 2 and 14, that are non-immunogenic, we have recently purified and described the CPS structures for serotypes 1, 1/2, 3, 7, 8, and 9. Here, we aimed to elucidate how these new structurally diverse CPSs interact with the immune system to generate anti-CPS antibody responses. CPS-stimulated dendritic cells produced significant levels of C–C moti…
Bioactive glass ions induce efficient osteogenic differentiation of human adipose stem cells encapsulated in gellan gum and collagen type I hydrogels
2019
Abstract Background Due to unmet need for bone augmentation, our aim was to promote osteogenic differentiation of human adipose stem cells (hASCs) encapsulated in gellan gum (GG) or collagen type I (COL) hydrogels with bioactive glass (experimental glass 2-06 of composition [wt-%]: Na2O 12.1, K2O 14.0, CaO 19.8, P2O5 2.5, B2O3 1.6, SiO2 50.0) extract based osteogenic medium (BaG OM) for bone construct development. GG hydrogels were crosslinked with spermidine (GG-SPD) or BaG extract (GG-BaG). Methods Mechanical properties of cell-free GG-SPD, GG-BaG, and COL hydrogels were tested in osteogenic medium (OM) or BaG OM at 0, 14, and 21 d. Hydrogel embedded hASCs were cultured in OM or BaG OM fo…