146 research outputs found

    Density, size structure, shell orientation and epibiontic colonization of the fan mussel <em>Pinna nobilis</em> L. 1758 (Mollusca: Bivalvia) in three contrasting habitats in an estuarine area of Sardinia (W Mediterranean)

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    Se investigó la distribución espacial, la estructura de tallas, la orientación de las conchas y la colonización de las valvas por parte de epibiontes, de la especie protegida Pinna nobilis en el Golfo de Oristano (Cerdeña, Mediterráneo Occidental). Las estaciones de muestreo se encontraban en tres hábitats continuos pero diferentes: una zona estuarina (E) de humedales costeros caracterizada por un fondo sin vegetación; una zona caracterizada por una amplia pradera de Posidonia oceanica (Mw) y una tercera compuesta de una pradera mixta parcheada de P. oceanica y Cymodocea nodosa (Me). La máxima densidad media se encontró en el estuario. La orientación de las conchas indicó una distribución circular y uniforme de los ejemplares en la estación Mw, y una distribución unimodal en las estaciones Me y E, donde los ejemplares estaban orientados a 0°N y 10°N-NE, patrón relacionado con las corrientes dominantes. La epibiosis de las conchas mostró diferencias entre los hábitats. La máxima colonización de las valvas fue en el estuario, con algas brunas filamentosas y Ostrea edulis, llegando a casi el 90% de cobertura de la concha. Este estudio ha permitido obtener nuevos datos sobre el hábitat preferencial de P. nobilis, y evaluar las poblaciones locales proporcionando informaciones útiles para el conocimiento de la ecología y mejorar la conservación de esta especie

    Effects of larval diet and metamorphosis cue on survival and growth of sea urchin post-larvae (Paracentrotus lividus; Lamarck, 1816)

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    In this study, we present the results of two experiments; in the first one we evaluated the effects of four larval dietary treatments on the survival and growth of the sea urchin Paracentrotus lividus, larvae and post-larvae. In the second experiment we have measured the effects of two different settlement substrates, combined with the presence of conspecifics, on metamorphosis, survival and growth of post-larvae. The microalgae dietary treatments consisted in: Dunaliella tertiolecta (Duna); 50% mixture of Isochrysis galbana and D. tertiolecta (ID); 50% mixture of Chaetoceros gracilis and D. tertiolecta (CD); 33% mixture of I. galbana, C. gracilis and D. tertiolecta (ICD). Although all dietary treatments resulted in a good survival at competence, significant difference in post-larval survival was observed between treatments, and indeed, only larvae fed Duna and CD survived to 180 days post settlement (DPS).&nbsp; In the second experiment, the settlement substrates consisted in a film of cultured Ulvella lens or a naturally developing biofilm of diatoms, and the employed rearing water was either natural seawater or seawater previously exposed to P. lividus adults. At 10 DPS, larger (p&lt;0.05) post-larvae were observed in the natural biofilm treatment, whilst the presence of conspecifics significantly increased larval settlement in both substrates (p&lt;0.01).&nbsp; These results indicate that it is important to consider the survival of post-larvae and juveniles to establish the efficiency of the dietary treatment on the hatchery production of P. lividus. Furthermore, it suggests that improved settlement protocols, such as the use of conspecifics, could contribute to increase hatchery outputs. Finally, it confirms the suitability of U. lens as settlement cue but also highlights that further research is required to establish its effectiveness for post-larvae first feedin

    Bioremediation of aquaculture wastewater from Mugil cephalus (Linnaeus, 1758) with different microalgae species

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    This is an Accepted Manuscript of an article published by Taylor & Francis Group in Chemistry and Ecology on 2017, available online at: http://www.tandfonline.com/10.1080/02757540.2017.1378351Current aquaculture practices have a detrimental impact on the environment, in particular due to the release of high concentration of nitrogen and phosphorus that can induce eutrophication. This study investigates and compares the capacity of three microalgae species Tetraselmis suecica, Isochrysis galbana and Dunaliella tertiolecta, in the bioremediation of grey mullet Mugil cephalus wastewater. The experiment was conducted in batch conditions for 7 days using completely mixed bubble column photobioreactors. After two days, T. suecica and D. tertiolecta were able to remove more than 90% of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorous (DIP), whereas I. galbana removed only 32% and 79% of DIN and DIP, respectively. A higher biomass yield resulted for T. suecica (603¿±¿34 mg/L, mean¿±¿SE). This study confirms the potential to employ T. suecica in an Integrated Multi-Trophic Aquaculture system for bioremediation of wastewater and identifies D. tertiolecta as another valid candidate species. Moreover, these species can growth in unsterilized culture media, and this reduces energy consumption, costs and efforts.Peer ReviewedPostprint (author's final draft

    Overcoming Ostrea edulis seed production limitations to meet ecosystem restoration demands in the UN decade on restoration

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    The European flat oyster, Ostrea edulis, is a habitat-forming bivalve which was historically widespread throughout Europe. Following its decline due to overfishing, pollution, sedimentation, invasive species, and disease, O. edulis and its beds are now listed as a threatened and/or declining species and habitat by OSPAR. Increasing recognition of the plight of the oyster, alongside rapidly developing restoration techniques and growing interest in marine restoration, has resulted in a recent and rapid growth in habitat restoration efforts. O. edulis seed supply is currently a major bottleneck in scaling up habitat restoration efforts in Europe. O. edulis has been cultured for centuries, however, research into its culture declined following the introduction of the Pacific oyster, Crassostrea gigas to Europe in the early 1970 s. Recent efforts to renew both hatchery and pond production of O. edulis seed for habitat restoration purposes are hampered by restoration project timelines and funding typically being short, or projects not planning appropriately for the timescales required for investment, research-and-development and delivery of oyster seed by commercial producers. Furthermore, funding for restoration is intermittent, making long-term commitments between producers and restoration practitioners difficult. Long-term, strategic investment in research and production are needed to overcome these bottlenecks and meet current ambitious restoration targets across Europe

    Notulae to the Italian alien vascular flora: 1

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    In this contribution, new data concerning the Italian distribution of alien vascular flora are presented. It includes new records, exclusions, and confirmations for Italy or for Italian administrative regions for taxa in the genera Agave, Arctotheca, Berberis, Bidens, Cardamine, Catalpa, Cordyline, Cotoneaster, Dichondra, Elaeagnus, Eragrostis, Impatiens, Iris, Koelreuteria, Lamiastrum, Lantana, Ligustrum, Limnophila, Lonicera, Lycianthes, Maclura, Mazus, Paspalum, Pelargonium, Phyllanthus, Pyracantha, Ruellia, Sorghum, Symphyotrichum, Triticum, Tulbaghia and Youngia

    LHCb upgrade software and computing : technical design report

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    This document reports the Research and Development activities that are carried out in the software and computing domains in view of the upgrade of the LHCb experiment. The implementation of a full software trigger implies major changes in the core software framework, in the event data model, and in the reconstruction algorithms. The increase of the data volumes for both real and simulated datasets requires a corresponding scaling of the distributed computing infrastructure. An implementation plan in both domains is presented, together with a risk assessment analysis

    Physics case for an LHCb Upgrade II - Opportunities in flavour physics, and beyond, in the HL-LHC era

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    The LHCb Upgrade II will fully exploit the flavour-physics opportunities of the HL-LHC, and study additional physics topics that take advantage of the forward acceptance of the LHCb spectrometer. The LHCb Upgrade I will begin operation in 2020. Consolidation will occur, and modest enhancements of the Upgrade I detector will be installed, in Long Shutdown 3 of the LHC (2025) and these are discussed here. The main Upgrade II detector will be installed in long shutdown 4 of the LHC (2030) and will build on the strengths of the current LHCb experiment and the Upgrade I. It will operate at a luminosity up to 2×1034 cm−2s−1, ten times that of the Upgrade I detector. New detector components will improve the intrinsic performance of the experiment in certain key areas. An Expression Of Interest proposing Upgrade II was submitted in February 2017. The physics case for the Upgrade II is presented here in more depth. CP-violating phases will be measured with precisions unattainable at any other envisaged facility. The experiment will probe b → sl+l−and b → dl+l− transitions in both muon and electron decays in modes not accessible at Upgrade I. Minimal flavour violation will be tested with a precision measurement of the ratio of B(B0 → μ+μ−)/B(Bs → μ+μ−). Probing charm CP violation at the 10−5 level may result in its long sought discovery. Major advances in hadron spectroscopy will be possible, which will be powerful probes of low energy QCD. Upgrade II potentially will have the highest sensitivity of all the LHC experiments on the Higgs to charm-quark couplings. Generically, the new physics mass scale probed, for fixed couplings, will almost double compared with the pre-HL-LHC era; this extended reach for flavour physics is similar to that which would be achieved by the HE-LHC proposal for the energy frontier
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