4,991 research outputs found

    Is juvenile anchovy a feeding resource for the demersal community in the Bay of Biscay? On the availability of pelagic prey to demersal predators

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    The role that juvenile anchovy (Engraulis encrasicolus) play as a food resource for the demersal community in the southern Bay of Biscay is assessed using 21 years of anchovy abundance data and demersal predator diets. During the study period, a total of 26 fish and elasmobranch species preyed on anchovy either frequently or occasionally. Predators with a crustacean-based diet targeted the smaller anchovy individuals. The size range of anchovy juveniles (centred at 7.5–8.9 cm) was comparable to that of the largest nektonic–benthic crustaceans, but generally smaller than other demersal and pelagic fish prey. Hake (Merluccius merluccius) and megrim (Lepidorhombus whiffiagonis) were the predators that consumed the highest number of anchovy, one of the main prey items driving the variability of their diets. Anchovy consumption conformed only partially to the abundance of anchovy in the southern Bay of Biscay, suggesting that factors other than abundance might condition its availability to demersal predators. Prey size could be one of them, as the size of the anchovy preyed on proved to be significantly smaller than the individuals collected with bottom trawls. However, other factors, such as the vertical position of the shoals of anchovy juveniles, could also constrain anchovy availability to demersal predators

    Wave farm planning through high-resolution resource and performance characterization

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    Wave farm planning in a coastal region should lead to the selection of: i) the type of technology of wave energy converter (WEC) providing the highest performance at specific sites and ii) the sites for wave farm operation allowing an integrated coastal zone management (ICZM). On these bases, the deployment of a wave farm should be based on an accurate analysis of the performance of different WECs at coastal locations where wave energy exploitation does not interfere with other coastal uses, and the environmental impact is minimised (or positive, e.g. allowing coastal protection). With this in view, in this piece of research the intra-annual performance of various WECs of the same type (buoy-type) is computed at different locations in NW Spain allowing an ICZM perspective. For this purpose, the intra-annual version of WEDGE-p® (Wave Energy Diagram Generator – performance) tool is implemented. The results show that, as opposed to previous analysis on WECs with different principle of operation, the level of performance of buoy-type WECs at specific locations may present strong similarities. In this case, an accurate computation of different performance parameters along with their joint analysis emerge as a prerequisite for an informed decision-making

    Covariant Momentum Map Thermodynamics for Parametrized Field Theories

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    Inspired by Souriau's symplectic generalization of the Maxwell-Boltzmann-Gibbs equilibrium in Lie group thermodynamics, we investigate a spacetime-covariant formalism for statistical mechanics and thermodynamics in the multi-symplectic framework for relativistic field theories. A general-covariant Gibbs state is derived, via a maximal entropy principle approach, in terms of the covariant momentum map associated with the lifted action of the diffeomorphisms group on the extended phase space of the fields. Such an equilibrium distribution induces a canonical spacetime foliation, with a Lie algebra-valued generalized notion of temperature associated to the covariant choice of a reference frame, and it describes a system of fields allowed to have non-vanishing probabilities of occupying states different from the diffeomorphism invariant configuration. We focus on the case of parametrized first-order field theories, as a concrete simplified model for fully constrained field theories sharing fundamental general covariant features with canonical general relativity. In this setting, we investigate how physical equilibrium, hence time evolution, emerge from such a state via a gauge-fixing of the diffeomorphism symmetry

    Anti-tumor activity of functionalized biomimetic magnetite nanoparticles produced in the presence of MamC protein of Magnetococcus marinus MC-1

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    Magnetite Nanoparticles (MNPs) find many applications, including biotechnology, as they can be manipulated by an external magnetic field and functionalized with different molecules. Magnetotactic bacteria bio-mineralize magnetosomes (membrane-enveloped magnetites), which are the ideal magnetic particle. However, scaling-up magnetosome production is still challenging, so bio-mimetics, i.e. in vitro magnetite synthesis mediated by magnetosome-associated proteins is being explored. Our group is working with MamC from Magnetococcus marinus MC-1 that controls the morphology and size of the crystals, producing well faceted Biomimetic Magnetic Nanoparticles (BMNPs) of ~40 nm, which are paramagnetic at room and body temperature while having a large magnetic moment per particle under an external magnetic field. These BMNPs were cytocompatible and biocompatible in vivo. BMNPs were functionalized (isothermal adsorption) with a monoclonal antibody (mAb) recognizing the ectodomain of the human Met/HGF receptor (overexpressed in many cancers) and the chemotherapeutic Doxorubicin (DOXO). The functionalized BMNPs present hyperthermia and were stable at physiological pH, while releasing the adsorbed DOXO at acidic pH. mAb functionalization of BMNPs favored their interaction with cells expressing the Met/HGFR and cellular DOXO uptake and toxicity, which was enhanced upon cell exposition to a continuous magnetic field. Real-time cytotoxicity of the BMNPs showed that DOXO-mAb-BMNPs were significantly more toxic than DOXO-BMNPs on Met/HGFR expressing cells, while no differential toxicity was observed on cells not expressing this receptor. When DOXO-BMNPs were injected intravenously in tumor bearing mice and an external magnetic field was applied there, a higher amount of BMNPs accumulated in the tumor and tumor growth was decreased in comparison to mice in which no magnetic field was applied. These BMNPs could thus represent effective nano-carriers for targeted drug delivery and might be combined with hyperthermia to increase efficiency, resulting in a targeted local treatment of tumors with a decrease in the deleterious systemic side effects

    The r'-band luminosity function of Abell1367: a comparison with Coma

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    We made a large (approximately 1degr x 1degr) r'-band imaging survey of the central regions of the two nearby clusters of galaxies, Abell1367 and Coma. The data, presented as a catalog, are used to construct the r'-band luminosity function (LF) of galaxies in these two clusters, by subtracting the Yasuda et al. (2001) galaxy counts from our cluster counts. Our Coma luminosity function is consistent with previous determinations, i.e. providing a faint end slope alpha = -1.47_-0.09^+0.08, significantly steeper than the one we find for Abell1367 (alpha = -1.07_-0.16^+0.20). The counts in Abell1367 show a relative minimum at r' ~ 19, followed by a steep increase faintward. The difference between the two clusters appears significant, given the consistency of the experimental conditions in the two clusters. Whereas for Coma we find a significant increase of the slope of the LF outwards, no such effect is found for Abell1367.Comment: 12 pages, 8 figures, accepted for publication in A&

    Produzione, mercato e consumi della cerasicoltura spagnola

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    La crisi di sovrapproduzione di alcune specie tradizionali sta favorendo la crescita del ciliegio, che mostra un costante incremento delle superfici, favorito dal rinnovamento varietale, dall’aumento dei consumi, dal miglioramento delle tecnologie di produzione e dalla precocità di maturazione. Tutti fattori che garantiscono alla Spagna elevata competitività nelle esportazioni verso i Paesi dell’Ue.Colaboración en el blog: Rivista di frutticoltura e di ortofloricoltura. Disponible: http://www.rivistafrutticoltura.it

    Microwave-assisted functionalization of carbon nanohorns with oligothiophene units with SERS activity

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    [EN] Carbon nanohorns have been functionalized with oligothiophene unitsviathe 1,3-dipolar cycloaddition reaction under microwave irradiation and solvent-free conditions. A dramatic Raman enhancement was found for one of the synthesized derivatives. Experimental andin silicostudies helped to understand the enhancement, attributed to the modification of electromagnetic fields upon functionalization at the tip of the nanostructures.This work was supported by the Iberdrola Foundation (CONV120313), the Spanish Ministerio de Economia y Competitividad (CTQ2017-88158-R), the Junta de Comunidades de Castilla-La Mancha (SBPLY/17/180501/000204) and FEDER-JCCM (UNCM13-1E-1663). The work at the University of Malaga was funded by the MICINN (PID2019-110305GB-I00) and Junta de Andalucia (P09FQM-4708) projects. M. I. L. acknowledges MINECO for her Juan de la Cierva-formacion grant (FJCI-2016-29593). The authors acknowledge the computer resources, technical expertise, and assistance provided by the Supercomputing and Bioinformatics centre of the University of Malaga.Iglesias, D.; Guerra, J.; Lucío, MI.; González-Cano, RC.; Lopez Navarrete, JT.; Ruiz Delgado, MC.; Vázquez, E.... (2020). Microwave-assisted functionalization of carbon nanohorns with oligothiophene units with SERS activity. Chemical Communications. 56(63):8948-8951. https://doi.org/10.1039/D0CC03496G89488951566

    Separación in situ de heces y orina mediante cinta de deyecciones bajo slat en alojamiento de cebo de ganado porcino

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    Se analizan los resultados de producción de heces y orina en dos ciclos de cebo completo con 168 animales utilizando un sistema de cinta de separacion de heces y orina bajo slat, patentado por parte de los miembros del equipo. Se estudia la influencia del tipo de cinta, de la inclinación de la misma y frecuencia de extracción. Tambien se controló la temepratura del aire tanto a la entrada como a la salida del alojamiento. Con el sistema se logra una eficaz separación de heces y orina, con una disminución notable en la producción de ambos residuos. La ventilaci¿on forzada permite reducir la cantidad de residuos generados

    Imprints of galaxy evolution on H ii regions Memory of the past uncovered by the CALIFA survey

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    H ii regions in galaxies are the sites of star formation and thus particular places to understand the build-up of stellar mass in the universe. The line ratios of this ionized gas are frequently used to characterize the ionization conditions. We use the Hii regions catalogue from the CALIFA survey (~5000 H ii regions), to explore their distribution across the classical [OIII]/Hbeta vs. [NII]/Halpha diagnostic diagram, and how it depends on the oxygen abundance, ionization parameter, electron density, and dust attenuation. We compared the line ratios with predictions from photoionization models. Finally, we explore the dependences on the properties of the host galaxies, the location within those galaxies and the properties of the underlying stellar population. We found that the location within the BPT diagrams is not totally predicted by photoionization models. Indeed, it depends on the properties of the host galaxies, their galactocentric distances and the properties of the underlying stellar population. These results indicate that although H ii regions are short lived events, they are affected by the total underlying stellar population. One may say that H ii regions keep a memory of the stellar evolution and chemical enrichment that have left an imprint on the both the ionizing stellar population and the ionized gasComment: 18 pages, 8 figures, accepted for publishing in A&

    Tropospheric Chemical Impact of Considering a Surrogate vs. an Explicit VSLBr Mechanism on the O3 and HOx Distributions within the CAM-Chem model

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    The contribution of very short-lived bromine (VSLBr) represent 5 ± 2 ppt (∼25%) of total stratospheric bromine (WMO, 2018), which is still nowadays dominated by long-lived bromocarbons that do not impact on tropospheric chemistry. Due to their shorter lifetimes, the overall injection to the stratosphere of VSLBr compounds possesses two distinct pathways: i) Source Gas Injection (SGI), where the brominated species are injected as they were emitted at the surface; and ii) Product Gas Injection (PGI), where the photochemical processing of reactive species arising from SG degradation must be considered. Depending on the partitioning and distribution of SGI and PGI, the chemical impact of VSLBr on tropospheric and lowermost stratospheric ozone, HOx and other oxidizing species can be very different. Many Chemistry Climate Models (CCMs) include a simplified treatment of tropospheric VSLBr sources by assuming a long-lived halocarbon (usually CH3Br) as a Surrogate for VSLBr. Even though these surrogate models possess a consistent evolution of the stratospheric bromine loading, CCMs including an explicit VSLBr representation compare better with organic and inorganic bromine observations in the lowermost stratosphere (Wales et al., 2018). Here we used the halogenated version of the CAM-Chem model (Fernandez et al., 2014) to evaluate the chemical impact of considering an explicit treatment of VSLBr versus considering a simplified tropospheric treatment of long-lived CH3Br as surrogate of VSLBr. The explicit mechanism considers a full gas- and aerosol- phase chemical scheme (including sea-salt dehalogenation) as well as time dependent and geographically-distributed VSLBr emissions inventory (Ordoñez et al., 2012), which replaces the typical lower-boundary surface conditions for longlived compounds usually considered in CCMs. An additional baseline simulation neglecting the contribution of VSLBr is also considered. First we show the differences in the overall inorganic bromine (Bry) burden as a function of altitude, latitude and time of the year, and compare the model changes on SGI and PGI for each model configuration. Based on the vertical and latitudinal Bry distributions, we focus the analysis on determining the surrogate vs. explicit VSLBr impact on the tropospheric ozone burden, as well as the changes in HOx and NOx mixing ratios within different regions. In particular, seasonal variations in the Odd-Oxygen chemical loss channels during within the marine boundary layer (MBL), tropical tropopause layer (TTL) and mid-latitudes upper troposphere (UT) are evaluated. Our results indicate that the impact of VSLBr species is strongly underestimated when a simplified treatment of tropospheric VSLBr chemistry is considered, which might have strong climatic impacts.Fil: Fernández, Rafael Pedro. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Barrera, Javier Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Iglesias Suarez, Fernando. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Cuevas, Carlos Alberto. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Kinnison, Douglas E.. No especifíca;Fil: Lamarque, Jean Francoise. No especifíca;Fil: Tilmes, Simone. No especifíca;Fil: Wales, Pamela. University of Maryland; Estados UnidosFil: Nicely, Julie M.. No especifíca;Fil: Salawitch, Ross J.. University of Maryland; Estados UnidosFil: Saiz Lopez, Alfonso. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; España. University of Maryland; Estados UnidosEGU General Assembly 2019VienaAustriaEuropean Geosciences Unio
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