685 research outputs found

    First record of the epizoic red seaweed Polysiphonia carettia Hollenberg in the Mediterranean Sea.

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    Primera cita del alga roja epizoica Polysiphonia carettia Hollenberg en el mar Mediterráneo Key words. Caretta caretta, epibionts, Mediterranean Sea, Polysiphonia carettia. Palabras claves. Caretta carom, cpibiontes, Mar Mediterráneo, Polysiphonia carettia

    Notas corológicas del mocrofitobentos de Andalucía (España). V

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    New records for the macrophytobenthos of Andalusia (Spain). V.Palabras clave. Andalucía, Asparagopsis taxiformis, Desmarestia dresnayi, Macroalgas marinas, Spatoglossum solierii.Key words. Andalusia, Asparagopsis taxiformis, Desmarestia dresnayi, Spatoglossum solierii, scaweeds

    Revisión crítica de los estudios sobre biogeografía de macroalgas marinas del Mediterráneo.

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    Revisión crítica de los estudios sobre biogeografía de macroalgas marinas del Mediterráneo. Teniendo en cuenta los procedimientos metodológicos que se siguen en los estudios biogeográficos, se reconocen tres tipos básicos de aproximaciones: biogeografía descriptiva, biogeografía narrativa y biogeografía analítica. En este trabajo se analizan las aportaciones realizadas a la ficogeografía de las macroalgas marinas del mar Mediterráneo, atendiendo a cada una de las tres aproximaciones posibles. Existen escasas floras del Mediterráneo oriental y la costa africana, además de un estancamiento metodológico en los estudios narrativos y analíticos, impidiendo el avance de la ficogeografía. Se discuten las posibles líneas futuras de investigación con el objeto de incentivar un avance significativo en los conocimientos ficogeográficos del Mediterráneo

    Diet digestibility in growing rabbits: effect of origin and oxidation level of dietary fat and vitamin e supplementation

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    [EN] The effects of the dietary inclusion of fats with different origin (lard or vegetal oil), fatty acid profile (linseed or sunflower), oxidation level (fresh, peroxidised: 11 d at 55ºC or oxidised: 31 h at 140ºC) and vitamin E supplementation (0 or 100 ppm) on the rabbit diet apparent digestibility were studied. Digestibility coefficients of dry matter, organic matter, crude protein, ether extract and gross energy were determined in eight diets using 58 rabbits aged 49 d. Contrast analysis between groups of diets showed that lard, characterised by a greater saturated fatty acid content, compared with vegetal oils, rich in unsaturated fatty acid, reduced the apparent digestibility of ether extract (62.3 vs. 68.4%; P=0.0329). However, there were no significant differences in the nutrient digestibility when linseed or sunflower oils (rich in [omega]-3 or in [omega]-6 polyunsaturated fatty acids, respectively) were compared. The oxidation degree of the sunflower oil and the supplementation with 100 ppm of vitamin E to the diets did not modify the apparent digestibility values of any dietary fraction.This work was financed by the Ministry of Science and Technology (AGL2003-06559-C02-02)Casado, C.; Moya, V.; Fernández, C.; Pascual Amorós, JJ.; Blas, E.; Cervera, C. (2010). Diet digestibility in growing rabbits: effect of origin and oxidation level of dietary fat and vitamin e supplementation. World Rabbit Science. 18(2). https://doi.org/10.4995/wrs.2010.18.0818

    Direct air capture based on ionic liquids: From molecular design to process assessment

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    Direct air capture is a key carbon dioxide removal technology to mitigate climate change and keep the global average temperature rise below 1.5–2 °C. This work addresses for the first time the use of ionic liquids for direct air capture connecting their material design by molecular simulation to process modelling. First, 26 different ionic liquids were designed through quantum chemical calculations and their isotherms were computed to identify those with a positive cyclic working capacity at conditions relevant for direct air capture. Then, the most promising ionic liquids were assessed via process simulations in Aspen Plus. A wide range of operating configurations were screened by modifying the key process variables: air velocity (1 – 3 m/s), solvent mass flow (5 – 50 t/h) and temperature (293 – 323 K), and regeneration pressure (0.1 – 1 bar) and temperature (373 – 393 K). Exergy, energy and productivity were computed to detect optimal operating conditions; moreover, a simplified economic analysis was carried out to highlight the major cost components. The direct air capture system based on [P66614][Im] exhibited the most exergy (5.44 – 16.73 MJ/kg) and energy (15.15 – 35.42 MJ/kg) efficiency for similar productivity (0.5 – 1.3 kg/(m3·h)) thanks to its enhanced cyclic capacity (0.6 – 0.3 mol/kg). The minimum exergy required by [P66614][Im]-based DAC process is slightly better than alkali scrubbing (6.21 MJ/kg) and in line with amine (5.59 MJ/kg) scrubbing. In addition, the assessed DAC process has a theoretical potential to operate in the range of 200 $/tCO2 under reasonable energy and plant expenses. We conclude this work providing guidelines to address future development of direct air capture technologies based on ionic liquidsThe authors are grateful to Ministerio de Ciencia e Innovacion ´ of Spain (project PID2020-118259RB-I00) and Comunidad de Madrid (project P2018/EMT4348) for financial suppor

    Selection for Robustness in Mutagenized RNA Viruses

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    Mutational robustness is defined as the constancy of a phenotype in the face of deleterious mutations. Whether robustness can be directly favored by natural selection remains controversial. Theory and in silico experiments predict that, at high mutation rates, slow-replicating genotypes can potentially outcompete faster counterparts if they benefit from a higher robustness. Here, we experimentally validate this hypothesis, dubbed the “survival of the flattest,” using two populations of the vesicular stomatitis RNA virus. Characterization of fitness distributions and genetic variability indicated that one population showed a higher replication rate, whereas the other was more robust to mutation. The faster replicator outgrew its robust counterpart in standard competition assays, but the outcome was reversed in the presence of chemical mutagens. These results show that selection can directly favor mutational robustness and reveal a novel viral resistance mechanism against treatment by lethal mutagenesis

    First record of the sea cucumber Parastichopus tremulus Gunnerus, 1767 (Echinodermata: Holothuroidea: Aspidochirotida) in the Mediterranean Sea (Alboran Sea, western Mediterranean)

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    The holothurian Parastichopus tremulus, a species only know from the north-eastern Atlantic, is reported for the first time from the Mediterranean Sea. Five individuals of the species were collected in the vicinity of the Seco de los Olivos sea mount in May 2017 from a bottom trawl sample carried out during the MEDITS trawl survey. Scanning Electron Microscope images of body wall ossicles are supplied to support species identification. Connectivity between Atlantic and Mediterranean populations of P. tremulus is suggested due to the existence of a nearby Atlantic population in the Gulf of Cádiz and the documented presence of abundant holothuroid larvae in the anticyclonic gyre which originates in the Atlantic current entering the Mediterranean, near the Strait of GibraltarPremier signalement du concombre de mer Parastichopus tremulus (Gunnerus, 1767) (Echinodermata : Aspidochirotida) en Méditerranée (Mer d’Alboran, Méditerranée occidentale). L’holothurie Parastichopus tremulus, une espèce connue seulement du nord-est Atlantique, est signalée pour la première fois en Mer Méditerranée. Cinq individus de l’espèce ont été récoltés près du mont sous-marin Seco de los Olivos en mai 2017 d’un échantillon de chalut de fond effectué pendant la campagne de recherche avec chalut MEDITS. Des photographies au microscope électronique à balayage d’osselets de la paroi du corps sont fournies pour valider l’identification de l’espèce. La connectivité entre les populations atlantiques et méditerranéennes de P. tremulus est suggérée en raison de la proximité d’une population atlantique dans le Golfe de Cádiz et de la présence documentée de larves d’holothurie abondantes dans le vortex anticyclonique originaire du courant atlantique entrant en Méditerranée, près du Détroit de GibraltarVersión del edito
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