Search results for " REE"
showing 10 items of 167 documents
New data on the Upper Triassic reefs of Western Sicily: stratigraphic constraints for the paleogeographic reconstruction of the Sicanian and Trapanes…
2005
Sea level rise in the Mediterranean Sea: High resolution constraints from vermetid reefs
2009
The Mediterranean Sea (MS), is extremely sensitive to rising sea-levels (SL) as attested by drowned archeological remains from the Roman Period [2]. Due to the absence of coral reefs, evidence for recent and Holocene SL change has so far mainly been restricted to coastal cores [1] archeological remains [2] and submerged speleothem deposits. Vermetid reefs are an extremely sensitive high resolution carbonate archive [3,4] and they are mainly formed in the lower intertidal zone by gregarious and sessile gastropods belonging to the genus Dendropoma (family Vermetidae). Since their interval of growth is restricted to the tidal zone, they can be used as precise SL proxies (about ±0.1 m in low ra…
Temporal dynamic of biofilms enhances the settlement of the central-Mediterranean reef-builder Dendropoma cristatum (Biondi, 1859).
2021
Abstract Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum. To elucidate settlement-related biofilm features, here we analyse the structure and composition of marine biofilms over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm coverage on the substratum and the reduction of th…
CONSERVATION NEEDS FOR THE VERMETID REEFS IN THE MEDITERRANEAN SEA
2015
Vermetid reefs are intertidal bioconstructions typical of many subtropical and temperate coastal areas worldwide. Distributed in the warmest waters of the Mediterranean Sea, the reefs are built by the vermetid gastropod Dendropoma petraeum and the coralline alga Neogoniolithon brassica-florida, two species included in the annexes of the Berna Convention. Vermetid reefs provide a wide set of ecosystem services, such as coastal protection from erosion, regulation of sediment transport and accumulation, serving as carbon deposit and increasing biodiversity at the intertidal level. Despite its vulnerability to several threats, such as pollution, spread of invasive species, ocean acidification a…
Discrimination of coral reflectance spectra in the Red Sea
2002
Benthic populations can potentially be mapped from remotely acquired spectral imagery, provided that they have distinctive reflectance signatures. We examined the spectral reflectance characteristics of 14 genera of Red Sea coral using a submersible spectroradiometer. Coral spectra varied quantitatively and qualitatively over the depth interval 5–20 m. Tissue pigment content had a larger effect on reflectance than colony morphology. Ten coral genera could be discriminated with a statistical probability of 52% on the basis of their absolute reflectance. Six groups of two to three coral genera could be discriminated with a probability of 60% on the basis of their rates of change in reflectanc…
Le Quaternaire franc-comtois. Essai chronologique et paléoclimatique.
1982
Le but de ce travail est d'établir le cadre chronologique et paléoclimatique du Quaternaire en Franche-Comté à partir de l'étude des formations édifiées au cours de cette période.Deux grands types de dépôts ont été plus particulièrement étudiés: ·- Les remplissages karstiques d'avens, de porches de grottes et d'abris sous roche, donnant un éclairage intense, mais ponctuel, de l'environnement physique et biologique, grâce aux faunes abondantes et aux indices climatiques d'ordre sédimentologique.- Les dépôts glaciaires et paraglaciaires (moraines, fluvioglaciaires, glacio-lacustres) qui permettent de situer des coupures climatiques au cours du temps dans l'espace géographique étudié.L'étude d…
SPATIAL DISTRIBUTION OF DENDROPOMA CRISTATUM (MOLLUSCA, GASTROPODA) ADULT BIOMASS ON A VERMETID REEF
2023
A spatial characterization of Dendropoma cristatum biomass was carried out on a Vermetid reef in north-western Sicily. Biomass distribution of adult specimens is not homogenous in the different areas of the reef, with an increasing trend from the inner edge to the outer edge, while the central pool supports intermediate values of vermetid biomass. Considering the entire reef area, the cuvette has the highest Dendropoma biomasses of the bioconstruction, even if the highest surface-biomass ratio is found in the outer edege.
La compensación como mecanismo de cumplimiento de las obligaciones tributarias. Identificación de las deudas y créditos que pueden ser objeto de exti…
2022
La tesis doctoral titulada “La compensación como mecanismo de cumplimiento de las obligaciones tributarias. Identificación de las deudas y créditos que pueden ser objeto de extinción y delimitación de los sujetos intervinientes” tiene por objeto de estudio el análisis de los aspectos materiales de la compensación como forma de extinción de las obligaciones tributarias pecuniarias. Entre las medidas para hacer efectiva la recaudación de los tributos se enmarca la compensación de deudas, figura que facilita el cumplimiento de las obligaciones tributarias de los administrados. Esta forma de extinción de la deuda tributaria alcanza en la actualidad una enorme importancia. En primer lugar, porqu…
El mito de la princesa: Blancanieves y la Bella Durmiente según Elfriede Jelinek
2011
Reescribir y reinterpretar cuentos tradicionales forma parte ya de una tradición literaria a la que no pocos autores se han sumado. El presente artículo ofrecerá un análisis de uno de estos intentos, llevado a cabo por la escritora austriaca Elfriede Jelinek. La autora ganadora del Premio Nobel de Literatura en 2004 publicó un año antes Dramas de princesas. La muerte y la doncella I-V, un conjunto de cinco obras concebidas como entreactos de otros espectáculos teatrales. De entre los modelos que la autora toma como referencia, los cuentos de hadas suponen el punto de partida para dos de los dramas, La muerte y la doncella I (Blancanieves) y La Muerte y la doncella II (La Bella Durmiente). E…
Assessment of the Sabellaria alveolata reefs’ structural features along the Southern coast of Sicily (Strait of Sicily, Mediterranean Sea)
2022
The honeycomb worm Sabellaria alveolata is a gregarious tube-dwelling polychaete that builds remarkable biogenic reefs in marine coastal waters. Sabellaria alveolata reefs are considered valuable marine habitats requiring protection measures for their conservation, as they play a key role in the functioning of coastal ecosystems. Sabellarid reefs are extensively developed along the Atlantic coasts of Europe and reported for the Mediterranean Sea and the Italian coasts, where large reefs have been recorded in several localities. Fragmentary information is available on their health status, Sabellaria reefs thus being listed as “Data Deficient” in the Red List of Marine Habitats. To fill this …