Search results for "posidonia"

Latest Cretaceous storm-generated sea grass accumulations in the Maastrichtian type area, the Netherlands – preliminary observations

2019

Abstract Ever since the first description of fossil material during the mid-nineteenth century, sea grass has been shown to be quite commonly preserved in ‘pockets’ or ‘clumps’ at certain levels within the Gulpen, Maastricht and Kunrade formations in southern Limburg (the Netherlands) and contiguous areas in northeast Belgium. In those places where silicification occurred during early diagenesis, even completely silicified and three-dimensionally preserved stems and roots can be found, mostly of Thalassocharis bosquetii, in association with fully marine molluscs such as dentaliid scaphopods and a range of larger foraminifera, bivalves, gastropods and ammonites. Such occurrences are best kno…

Origin and distribution of suspended organic matter as inferred from carbon isotope composition in a Mediterranean semi-enclosed marine system

1999

The origin and distribution of suspended organic matter, the trophic features and the stable carbon isotopic composition of particulate organic carbon (POC) were studied monthly in a Western Mediterranean semi-enclosed basin. Sampling stations were selected as a function of wind-exposure and the degree of vegetation cover and then compared with an adjacent unvegetated site. The predominant vegetation was seagrass (Posidonia oceanica and Cymodocea nodosa) and Caulerpa prolifera. Water samples were analyzed for total suspended matter (inorganic and organic fractions), photosynthetic pigments (chlorophyll-a and phaeopigments), dissolved organic carbon, particulate organic carbon and their isot…

An Innovative Soil Bioengineering Technique by Waste Materials: The RiVite Project

2023

This paper describes the RiVite project granted by the Italian Ministry of Economic Development according to the JUMP (Joint Universities Program for PoC) program for patents enhancement, proposed by Sant’Anna School, Scuola Normale and the University of Palermo. The patent (Calvo, R., D’Asaro, F., Baiamonte, G.: Metodo per la realizzazione di un’opera costruttiva modulare per la protezione del territorio e detta opera. Attestato di Brevetto per Invenzione Industriale, n° 102,017,000,141,369, Ministero dello Sviluppo Economico, Roma, 27/02/2020.) consists of an advanced soil bioengineering work providing anti-erosion function, consolidating and stabilizing of slopes, thus for land protectio…

Nouvelles connaissances sur les herbiers tigrés de Méditerranée.

2010

International audience; Les herbiers à Posidonia oceanica présentent plusieurs types morpho-structuraux généralement conditionnés par les conditions de milieu (profondeur, hydrodynamisme, substrat, pente, turbidité, sédimentation). Du fait de leur rareté, deux structures particulières, les récifs barrière et les herbiers tigrés, sont considérées depuis une vingtaine d'années comme des paysages marins menacés. Initialement décrits dans le golfe de Gabés, à proximité des îles Kerkennah, les herbiers tigrés se présentent sous forme " de rubans assez étroits qui se développent entre 0.5 et 3 m de profondeur sur matte ". La mise en place de nouveaux programmes d'études …

ANTIMICROBIAL AND ANTIBIOFILM ACTIVITY OF A PEPTIDE IDENTIFIED IN THE SEAGRASS POSIDONIA OCEANICA

2022

Modeling of the effect of EDTA on copper(II) biosorption onto Posidonia oceanica waste in batch and fixed-bed systems

2014

Abstract The performance of Posidonia oceanica for copper(II) biosorption in the presence of EDTA was investigated in batch and column experiments. In batch mode, copper(II) uptake in the presence of EDTA was lower than in its absence for the pH range 1.5–6.0. The decrease in the copper(II) uptake, attributed to the change in the chemical speciation of copper(II) with EDTA in solution, was from 71.7 to 58.8 mg/g in the absence and presence of EDTA respectively at pH 6. Column experiments were carried out at 5 and 20 mg Cu(II)/dm 3 and different doses of EDTA. Constant copper(II) leaks were detected in the effluent of the columns. Leak concentrations matched the copper(II)-EDTA complexes’ co…

Gravity-Driven Infiltration and Subsidence Phenomena in Posidonia oceanica Residues

2019

A simplified infiltration model for highly permeable porous media was introduced, assuming the matric potential gradient as negligible compared to the gravitational gradient. This model enabled us to determine the delay time, i.e., the time that the water front takes (from the beginning of rainfall) to reach the bottom of the highly permeable layer. Posidonia oceanica (Linnaeus) Delile residues were used as a porous media, in order to study the infiltration process that provides salt leaching under natural rainfall when these residues are arranged in a storage area, before reusing. By using a laboratory rainfall simulator, delay times were measured to verify the applicability of the aforeme…

In vitro effects of extracts from leaves and rhizomes of P.oceanica on HepG2 tumor cells

2023

Hydrolytic degradation of PLA/Posidonia Oceanica green composites: A simple model based on starting morpho-chemical properties

2021

Abstract In this work, we studied the degradability of PLA-based biocomposites containing Posidonia Oceanica flour at different loading levels and aspect ratios. Hydrolytic tests were carried out in neutral (pH = 7.4) and alkaline (pH = 10) environment. Time-dependent evolution of some key features, including residual mass and solution uptake, was monitored, and correlated with the changes observed in both morphology and chemical structure of the matrix. The results pointed out that biocomposites degraded much faster than neat PLA in both conditions, up to lose 70% of their initial weight after 1000 h immersion. A complex mechanism was unveiled, evidencing the crucial role of the fillers, c…

Relationships between sediment physico-chemical characteristics and heavy metal bioaccumulation in Mediterranean soft-bottom macrophytes

2001

Abstract Concentrations of Hg, Cd, Pb and Zn in the two seagrasses ( Posidonia oceanica and Cymodocea nodosa ), green alga Caulerpa prolifera and sediment and some physico-chemical characteristics of the sediment (organic matter, fine fraction (particles Significant correlations between the concentrations of metals in the plants and sediment (alone or normalized with respect to the physico-chemical characteristics) were usually found for Hg and Zn. For Pb only C . prolifera fractions were correlated to the Pb content of the sediment. For Cd no significant correlations were obtained between the metal in the plants and sediment. The concentration factors of the metals in the plants with respe…