Search results for "Pearl"
showing 10 items of 53 documents
Conservation status of freshwater mussels in Europe: state of the art and future challenges
2016
Freshwater mussels of the Order Unionida provide important ecosystem functions and services, yet many of their populations are in decline. We comprehensively review the status of the 16 currently recognized species in Europe, collating for the first time their life-history traits, distribution, conservation status, habitat preferences, and main threats in order to suggest future management actions. In northern, central, and eastern Europe, a relatively homogeneous species composition is found in most basins. In southern Europe, despite the lower species richness, spatially restricted species make these basins a high conservation priority. Information on freshwater mussels in Europe is uneve…
'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…
Nutritional properties and plausible benefits of Pearl millet (Pennisetum glaucum) on bone metabolism and osteoimmunology : a mini-review
2020
Bone is a hard connective tissue that undergoes a systematic renewal. This highly dynamic organ is made up of four different types of cells, however, bone formation is commonly attributed to osteoblasts and bone resorption to osteoclasts. Bone tissue formation occurs during embryonic development and in certain post-birth pathological conditions. The immune system could influence the functions of bone cells, and the crosstalk between hematopoietic, immune, and bone cells is known as osteoimmunology. Indeed, cytokines produced by immune cells, including TNF-α and IL-6, are critically implicated in bone pathogenesis. It is well established that diet plays an important role in bone health and f…
Polyphenols from Pennisetum glaucum grains induce MAP kinase phosphorylation and cell cycle arrest in human osteosarcoma cells
2019
Abstract Osteosarcoma is the most common bone tumor with a high prevalence among children and adolescents. Polyphenols are widely investigated for their chemopreventive and chemotherapeutic proprieties. In the present study, we explored the pro-apoptotic effects of pearl millet, Pennisetum glaucum, phenolic compounds (PGPC) on osteosarcoma U-2OS cells. Our results show that PGPC induced U-2OS cells death, in a dose dependent manner, with an IC50 of 80 μg/mL. Annexin-V and 7-AAD staining show that PGPC induced cell death mainly through caspase-dependent apoptosis as shown by a decrease in cell death when co-treated with pan-caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketon…
Thermal stability of nacre proteins of the polynesian pearl oyster: a proteomic study.
2015
Mollusc shells are organic-inorganic composites that are often preserved in the fossil record. However, the way the organic fraction, also called shell matrix, gets fossilized remains an unsolved question, in spite of several old and more recent studies. In the present paper, we have tried to mimic a diagenetic process by constantly heating for ten days at 100°C fresh nacre powder samples of the Polynesian pearl oyster Pinctadamargaritifera. Each day, aliquots of nacre powder were sampled and the matrix was subsequently extracted. It was further analysed by direct weigh quantification, by immunological techniques and by proteomics. Our preliminary data suggest that nacre proteins, when heat…
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…
The ‘Shellome’ of the Crocus Clam Tridacna crocea Emphasizes Essential Components of Mollusk Shell Biomineralization
2021
Molluscan shells are among the most fascinating research objects because of their diverse morphologies and textures. The formation of these delicate biomineralized structures is a matrix-mediated process. A question that arises is what are the essential components required to build these exoskeletons. In order to understand the molecular mechanisms of molluscan shell formation, it is crucial to identify organic macromolecules in different shells from diverse taxa. In the case of bivalves, however, taxon sampling in previous shell proteomics studies are focused predominantly on representatives of the class Pteriomorphia such as pearl oysters, edible oysters and mussels. In this study, we hav…
The onset of the rainy season and farmers’ sowing strategy for pearl millet cultivation in Southwest Niger
2011
A multi-year (2004-2009) field survey of on-farm sowing practices in 10 villages located in south-west Niger close to Niamey, is analysed to investigate the relationships (i) between rainfall and the sowing date of pearl millet and the risk of sowing failure, (ii) between sowing and meteorological/agro-climatic onset dates, (iii) between sowing/onset dates, and simulated and observed yield/biomass at the end of the season. Even if some villages sow without any synchronous or anterior rainfall, most parcels (73% out of the 1551 available cases) are sown during and just after a 2-day wet spell receiving at least 10 mm. In fact, there is a strong correlation (r = 0.82-0.95 depending on onset d…
Competition of coagulation sink and source rate: New particle formation in the Pearl River Delta of China
2010
The coagulation sink and its role in new particle formation are investigated based on data obtained during the PRIDE-PRD2004 campaign at Xinken of Pearl River Delta, China. Analysis of size distributions and mode contributions of the coagulation sink show that the observed higher load of accumulation mode particles impose a significant effect on the coagulation sink and result in higher coagulation sinks at Xinken despite of the lower total particle number compared with other areas. Hence it is concluded that the higher coagulation sink may depress the occurrence frequency of new particle formation events. The strategies targeting at controlling accumulation mode particles may have influenc…
Development of a big data bank for PV monitoring data, analysis and simulation in COST Action 'PEARL PV'
2019
COST Action entitled PEARL PV aims at analyzing data of monitored PV systems installed all over Europe to quantitatively evaluate the long-term performance and reliability of these PV systems. For this purpose, a data bank is being implemented that can contain vast amounts of data, which will enable systematic performance analyses in combination with simulations. This paper presents the development process of this data bank.