Search results for " shell"
showing 10 items of 307 documents
'Palaeoshellomics' reveals the use of freshwater mother-of-pearl in prehistory
2019
The extensive use of mollusc shell as a versatile raw material is testament to its importance in prehistoric times. The consistent choice of certain species for different purposes, including the making of ornaments, is a direct representation of how humans viewed and exploited their environment. The necessary taxonomic information, however, is often impossible to obtain from objects that are small, heavily worked or degraded. Here we propose a novel biogeochemical approach to track the biological origin of prehistoric mollusc shell. We conducted an in-depth study of archaeological ornaments using microstructural, geochemical and biomolecular analyses, including ‘palaeoshellomics’, the first…
Shell palaeoproteomics: first application of peptide mass fingerprinting for the rapid identification of mollusc shells in archaeology.
2020
10 pages; International audience; Molluscs were one of the most widely-used natural resources in the past, and their shells are abundant among archaeological findings. However, our knowledge of the variety of shells that were circulating in prehistoric times (and thus their socio-economic and cultural value) is scarce due to the difficulty of achieving taxonomic determination of fragmented and/or worked remains. This study aims to obtain molecular barcodes based on peptide mass fingerprints (PMFs) of intracrystalline proteins, in order to obtain shell identification. Palaeoproteomic applications on shells are challenging, due to low concentration of molluscan proteins and an incomplete unde…
Unveiling the evolution of bivalve nacre proteins by shell proteomics of Unionoidae.
2015
The formation of the molluscan shell nacre is regulated to a large extent by a matrix of extracellular macromolecules that are secreted by the shell forming tissue, the mantle. This so called “calcifying matrix” is a complex mixture of proteins and glycoproteins that is assembled and occluded within the mineral phase during the calcification process. While the importance of the calcifying matrix to shell formation has long been appreciated, the molecular basis that dictates nacre formation remains largely uncharacterized.Recent expressed sequence tag (EST) investigations of the freshwater mussels (Elliptio complanata and Villosa leinosa) provide an opportunity to further characterize the pr…
Self-packed core shell nano liquid chromatography columns and silica-based monolithic trap columns for targeted proteomics.
2016
Self-preparation of nano liquid chromatography (nLC) columns has advantages regarding cost and flexibility. For targeted proteomics, we evaluated several approaches for particle-packing nLC columns and manufacturing fritless silica-based monolithic trap columns (50μm inner diameter). Our preferred approach for nLC column preparation was to magnetically stir Accucore core shell particles (C18 stationary phase) in ACN/water (80/20, v/v) suspensions during pressure-driven filling of polymer-fritted standard fused silica capillaries. The columns were ready for use about one hour after preparation had begun. They had comparable peak capacities (peptides) to commercial columns, and satisfactory w…
Skeletal organic matrices in molluscs: origin, evolution, diagenesis
2017
8 pages; International audience; The mollusc shell comprises a small amount of organic macromolecules, mostly proteins and polysaccharides, which, all together, constitute the skeletal organic matrix (SOM). In the recent years, the study of the SOM of about two dozens of mollusc species via transcriptomics and/or proteomics has led to the identification of hundreds of shell-associated proteins. This rapidly growing set of data allows several comparisons, shedding light on similarities and differences at the primary structure level and on some peculiar evolutionary mechanisms that may have affected SOM proteins. In addition, it constitutes a prerequisite for investigating the SOM repertoires…
The shell of the invasive bivalve species Dreissena polymorpha: biochemical, elemental and textural Investigations.
2016
28 pages; International audience; The zebra mussel Dreissena polymorpha is a well-established invasive model organism. Although extensively used in environmental sciences, virtually nothing is known of the molecular process of its shell calcification. By describing the microstructure, geochemistry and biochemistry/proteomics of the shell, the present study aims at promoting this species as a model organism in biomineralization studies, in order to establish a bridge with ecotoxicology, while sketching evolutionary conclusions. The shell of D. polymorpha exhibits the classical crossed-lamellar/complex crossed lamellar combination found in several heterodont bivalves, in addition to an extern…
8.2 ka event North Sea hydrography determined by bivalve shell stable isotope geochemistry.
2019
AbstractThe abrupt 8.2 ka cold event has been widely described from Greenland and North Atlantic records. However, its expression in shelf seas is poorly documented, and the temporal resolution of most marine records is inadequate to precisely determine the chronology of major events. A robust hydrographical reconstruction can provide an insight on climatic reaction times to perturbations to the Atlantic Meridional Overturning Circulation. Here we present an annually-resolved temperature and water column stratification reconstruction based on stable isotope geochemistry of Arctica islandica shells from the Fladen Ground (northern North Sea) temporally coherent with Greenland ice core record…
The sensory and nutritional experience of parents guide offsprings' feeding behavior
2016
Le comportement alimentaire est régulé par des facteurs physiologiques intrinsèques et est largement influencé par l’environnement culturel. Une prise alimentaire excessive et un mode de vie trop sédentaire sont les principales raisons de l’épidémie mondiale d’obésité. Si l’influence du contexte familial sur les habitudes alimentaires ne fait aucun doute, le fait que l’état nutritionnel, métabolique et hormonal des parents avant la conception, puis de la mère pendant la gestation et l’allaitement puisse influencer le comportement alimentaire futur de l’enfant est un concept novateur qui ouvre la voie à des mesures de prévention. Au cours des dernières décennies, des travaux sur des cohortes…
Surface charges at the CaF2/water interface allow very fast intermolecular vibrational-energy transfer
2020
Abstract We investigate the dynamics of water in contact with solid calcium fluoride, where at low pH, localized charges can develop upon fluorite dissolution. We use 2D surface‐specific vibrational spectroscopy to quantify the heterogeneity of the interfacial water (D2O) molecules and provide information about the sub‐picosecond vibrational‐energy‐relaxation dynamics at the buried solid/liquid interface. We find that strongly H‐bonded OD groups, with a vibrational frequency below 2500 cm−1, display very rapid spectral diffusion and vibrational relaxation; for weakly H‐bonded OD groups, above 2500 cm−1, the dynamics slows down substantially. Atomistic simulations based on electronic‐structu…
Quantum-chemical determination of Born–Oppenheimer breakdown parameters for rotational constants: the open-shell species CN, CO+ and BO
2013
The quantum-chemical protocol for computing Born-Oppenheimer breakdown corrections to rotational constants in the case of diatomic molecules is extended to open-shell species. The deviation from the Born-Oppenheimer equilibrium rotational constant is obtained by considering three contributions: the adiabatic correction to the equilibrium bond distance, the electronic contribution to the moment of inertia requiring the computation of the rotational g-tensor, and the so-called Dunham correction. Values for the Born-Oppenheimer breakdown parameters of CN, CO+, and BO in their (2)sigma(+) electronic ground states are reported based on coupled-cluster calculations of the involved quantities and …