91 research outputs found

    Optimizing the ship constructions by automatic line heating forming process based in numerical simulation and artificial intelligence

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    This paper presents the development of a novel automatic lineheating forming machine based on intensive application of the numerical simulation and artificial intelligence. The forming of certain parts of the shell of the ships can be done by heating forming or mechanical forming. Line heating forming is usually a more flexible process, and therefore, it is more useful. The principal problem with line heating forming is that it is very time consuming, manual and needs very qualified workers. In this research, line heating forming is studied looking for the best way to automate the process. Numerical models were developed based on finite element methods to simulate the process of heating, cooling and finally forming of the plates. The models were tested and validated against experimental test over small plates. However, as numerical models have extremely long computational times demanding high computational capacities; they are not directly applicable in a real time scenario, as it is needed. Finally, after the mathematization of this knowledge and making use of it, it was developed a software based on artificial intelligence. Using an informed heuristic search strategy, this software predicts the optimal set of heating lines, their sequence and velocity to be applied over the plate to obtain the final shape. The developed system was tested to show its feasibility. As a consequence, there is a significative reduction in computational time allowing the system to be applied in a soft real-time environment. This model will help shipyard manufacturers determine the positions and trajectory of torch for the flame heating lines and their heating parameters to form a desired shape of plate

    Growth data from a field trial of Quercus suber plants regenerated from selected trees and their half-sib progenies by somatic embryogenesis

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    The development of reliable clonal propagation technologies is a requisite for performing Multi-Varietal Forestry (MVF). Somatic embryogenesis is considered the tissue culture based method more suitable for operational breeding of forest trees. Vegetative propagation is very difficult when tissues are taken from mature donors, making clonal propagation of selected trees almost impossible. We have been able to induce somatic embryogenesis in leaves taken from mature oak trees, including cork oak (Quercus suber). This important species of the Mediterranean ecosystem produces cork regularly, conferring to this species a significant economic value. In a previous paper we reported the establishment of a field trial to compare the growth of plants of somatic origin vs zygotic origin, and somatic plants from mature trees vs somatic plants from juvenile seedlings. For that purpose somatic seedlings were regenerated from five selected cork oak trees and from young plants of their half-sib progenies by somatic embryogenesis. They were planted in the field together with acorn-derived plants of the same families. After the first growth period, seedlings of zygotic origin doubled the height of somatic seedlings, showing somatic plants of adult and juvenile origin similar growth. Here we provide data on height and diameter increases after two additional growth periods. In the second one, growth parameters of zygotic seedlings were also significantly higher than those of somatic ones, but there were not significant differences in height increase between seedlings and somatic plants of mature origin. In the third growth period, height and diameter increases of somatic seedlings cloned from the selected trees did not differ from those of zygotic seedlings, which were still higher than data from plants obtained from somatic embryos from the sexual progeny. Therefore, somatic seedlings from mature origin seem not to be influenced by a possible ageing effect, and plants from somatic embryos tend to minimize the initial advantage of plants from acorn

    Informe del seguimiento científico de la acción piloto RAI/AP-26/2007: Pesca experimental con arte de arrastre de fondo en el Golfo de León (Mediteráneo noroccidental)

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    RESUMEN.- Del 24 de Octubre al 18 de Diciembre de 2007, se han realizado 67 pescas experimentales de arrastre de fondo, a bordo de las embarcaciones B/P Berto y B/P Sort de Taranet, en caladeros del talud del Golfo de León, situados en aguas internacionales al este del Cabo Creus y alejados entre 70 y 100 millas de su puerto base (Port de la Selva). Ambos barcos trabajaron de manera continuada durante 46 horas semanales (su período de actividad habitual es de 5 días semanales y 12 ó 16 horas diarias), utilizando una red de arrastre tipo cuadrado-dragón, que habitualmente usan para sus operaciones de pesca comercial en el área. De manera simultánea, un barco utilizó el copo tradicional de malla rómbica de 40 mm, mientras que el otro utilizó un copo de malla cuadrada de 40 mm. Ello permitió comparar la selectividad de ambos copos por el método de pescas paralelas. Del total de pescas, 50 fueron consideradas válidas para el análisis de datos, en base a dos estratos batimétricos: (i) 300-450 m, dirigidas a cigala (B/P Berto: 14 pescas entre 357 y 434 m; B/P Sort de Taranet: 14 pescas entre 371 y 451 m); (ii) 450-700 m, dirigidas a gamba roja (B/P Berto: 11 pescas entre 478 y 692 m; B/P Sort de Taranet: 11 pescas entre 493 y 571 m). Se han estimado los rendimientos medios, estandarizados a hora de arrastre efectivo, su fracción comercial y descartada y la distribución de tallas de las principales especies de interés comercial y ecológico. Paralelamente, se ha recogido información de los desembarcos y consumo de combustible esta acción piloto y para el mismo período de 2006, en que estas embarcaciones realizaron su actividad pesquera rutinaria. El análisis de esta información se ha realizado mediante técnicas uni- y multi-variantes. Los elevados rendimientos, así como la distribución de tallas de la captura de las principales especies explotadas, indican que los fondos prospectados están poco explotados. En ambos estratos batimétricos, con la malla cuadrada se redujeron los descartes, sin una disminución significativa de los rendimientos comerciales. Del mismo modo, la estrategia de pesca aplicada durante la acción piloto redujo el esfuerzo efectivo de pesca, sin disminuir el rendimiento de la pesquería respecto del mismo período de 2006. Además, se redujo considerablemente el consumo de combustible, lo que repercutió positivamente en las tasas de combustible consumido por unidad de desembarcos. La estrategia de explotación aplicada en la acción piloto mejora la relación coste-eficiencia de la pesquería y presenta una serie de ventajas, tanto de mejora en el rendimiento pesquero y en la explotación de los recursos, como de carácter medioambiental y social. No obstante, aplicar esta estrategia a la explotación comercial conlleva riesgos para el mantenimiento de los stocks de especies explotadas y la conservación de hábitats de especial interés y ecosistemas marinos vulnerables, en un área con numerosos cañones submarinos, como el Golfo de León.RESUM.- INFORME DEL SEGUIMENT CIENTÍFIC DE L’ACCIÓ PILOT RAI/AP-26/2007: PESCA EXPERIMENTAL AMB ART DE RÒSSEC DE FONS EN EL GOLF DE LLEÓ (MEDITERRÀNIA NOR-OCCIDENTAL): Del 24 de Octubre al 18 de Desembre de 2007, s’han dut a terme 67 pesques experimentals de ròssec de fons, a bord de les embarcacions B/P Berto i B/P Sort de Taranet, en caladors del talús del Golf de Lleó, situats en aigües internacionals a l’est del Cap de Creus, allunyats entre 70 i 100 milles del seu port base (Port de la Selva). Ambdós vaixells van treballar de manera continuada durant 46 hores setmanals (el seu període d’activitat habitual és de 5 dies setmanals i 12 ó 16 hores diàries), utilitzant una xarxa de ròssec de tipus quadratdragó, que habitualment utilitzen per les operacions de pesca comercial a l’àrea. De manera simultània, un vaixell va emprar el cóp tradicional de malla ròmbica de 40 mm, mentre que l’altre va emprar un cóp de malla quadrada de 40 mm. Això va permetre comparar la selectivitat d’ambdós cóps, mitjançant el mètode de pesques paral·leles. Del total de pesques, 50 foren considerades vàlides per l’anàlisi de dades, en base a dos estrats batimètrics: (i) 300-450 m, dirigides a escamerlà (B/P Berto: 14 pesques entre 357 i 434 m; B/P Sort de Taranet: 14 pesques entre 371 i 451 m); (ii) 450-700 m, dirigides a gamba vermella (B/P Berto: 11 pesques entre 478 i 692 m; B/P Sort de Taranet: 11 pesques entre 493 i 571 m). S’han estimat els rendiments mitjans, estandarditzats a hora efectiva de ròssec, la seva fracció comercial i rebutjada i la distribució de talles de les principals espècies d’interès comercial i ecològic. Paral·lelament, s’ha recollit informació dels desembarcaments i consum de combustible durant l’acció pilot de 2007 i pel mateix període de 2006, en que aquestes embarcacions van realitzar la seva activitat pesquera rutinària. L’anàlisi d’aquesta informació s’ha realitzat mitjançant tècniques uni- i multi-variants. Els elevats rendiments, així com la distribució de talles de la captura de les principals espècies explotades, indiquen que els fons prospectats estan poc explotats. En ambdós estrats batimètrics, amb la malla quadrada es van reduir els rebuigs, sense una disminució significativa dels rendiments comercials. De manera semblant, l’estratègia de pesca aplicada durant l’acció pilot va reduir l’esforç efectiu de pesca, sense disminuir el rendiment de la pesquera respecte del mateix període de 2006. A més, es va reduir considerablement el consum de combustible, la qual cosa va repercutir positivament en les tases de combustible consumit per unitat de desembarcaments. L’estratègia d’explotació aplicada en l’acció pilot incrementa la relació cost-eficiència de la pesquera i presenta una sèrie d’avantatges, tant de millora en el rendiment pesquer i en l’explotació dels recursos, com de caràcter mediambiental i social. No obstant, aplicar aquesta estratègia a l’explotació comercial comporta riscs pel manteniment dels estocs d’espècies explotades i la conservació d’hàbitats d’especial interès i ecosistemes marins vulnerables, a una àrea amb nombrosos canons submarins, com el Golf de Lleó.Secretaria General de Pesca Marítim

    TRAIL/TRAIL Receptor System and Susceptibility to Multiple Sclerosis

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    The TNF-related apoptosis inducing ligand (TRAIL)/TRAIL receptor system participates in crucial steps in immune cell activation or differentiation. It is able to inhibit proliferation and activation of T cells and to induce apoptosis of neurons and oligodendrocytes, and seems to be implicated in autoimmune diseases. Thus, TRAIL and TRAIL receptor genes are potential candidates for involvement in susceptibility to multiple sclerosis (MS). To test whether single-nucleotide polymorphisms (SNPs) in the human genes encoding TRAIL, TRAILR-1, TRAILR-2, TRAILR-3 and TRAILR-4 are associated with MS susceptibility, we performed a candidate gene case-control study in the Spanish population. 59 SNPs in the TRAIL and TRAIL receptor genes were analysed in 628 MS patients and 660 controls, and validated in an additional cohort of 295 MS patients and 233 controls. Despite none of the SNPs withstood the highly conservative Bonferroni correction, three SNPs showing uncorrected p values<0.05 were successfully replicated: rs4894559 in TRAIL gene, p = 9.8×10−4, OR = 1.34; rs4872077, in TRAILR-1 gene, p = 0.005, OR = 1.72; and rs1001793 in TRAILR-2 gene, p = 0.012, OR = 0.84. The combination of the alleles G/T/A in these SNPs appears to be associated with a reduced risk of developing MS (p = 2.12×10−5, OR = 0.59). These results suggest that genes of the TRAIL/TRAIL receptor system exerts a genetic influence on MS

    New insights into the neolithisation process in southwest Europe according to spatial density analysis from calibrated radiocarbon dates

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    The agricultural way of life spreads throughout Europe via two main routes: the Danube corridor and the Mediterranean basin. Current archaeological literature describes the arrival to the Western Mediterranean as a rapid process which involves both demic and cultural models, and in this regard, the dispersal movement has been investigated using mathematical models, where the key factors are time and space. In this work, we have created a compilation of all available radiocarbon dates for the whole of Iberia, in order to draw a chronological series of maps to illustrate temporal and spatial patterns in the neolithisation process. The maps were prepared by calculating the calibrated 14C date probability density curves, as a proxy to show the spatial dynamics of the last hunter-gatherers and first farmers. Several scholars have pointed out problems linked with the variability of samples, such as the overrepresentation of some sites, the degree of regional research, the nature of the dated samples and above all the archaeological context, but we are confident that the selected dates, after applying some filters and statistical protocols, constitute a good way to approach settlement spatial patterns in Iberia at the time of the neolithisation process

    Database of spatial distribution of non indigenous species in Spanish marine waters

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    Research in marine Spanish waters are focused on several actions to achieve an effectively management on protected areas, with the active participation of the stakeholders and research as basic tools for decision-making. Among these actions, there is one about the knowledge and control on NIS. One of its objectives is the creation of NIS factsheets, which are going to be added to the National Marine Biodiversity Geographical System (GIS) providing complementary information about taxonomic classification, common names, taxonomic synonyms, species illustrations, identification morphological characters, habitat in the native and introduced regions, biological and ecological traits, GenBank DNA sequences, world distribution, first record and evolution in the introduced areas, likely pathways of introduction, effects in the habitats and interaction with native species, and potential management measures to apply. The database will also provide data for (1) the European online platforms, (2) the environmental assessment for the Descriptor 2 (D2-NIS) of the EU Marine Strategy Framework Directive (MSFD), as well as (3) supporting decisions made by stakeholders. It is the result of extensive collaboration among scientist, manager’s and citizen science in the Spanish North-Atlantic, South-Atlantic, Gibraltar Strait-Alboran, Levantine-Balearic and Canary Islands marine divisions, providing an updated overview of the spatial distribution of relevant extended and invasive NIS of recent and established NIS introduced by maritime transport and aquaculture pathways, as well as on cryptogenic or native species in expansion due to the climatic water warming trend

    The CARMENES search for exoplanets around M dwarfs. Two temperate Earth-mass planet candidates around Teegarden’s Star

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    Context.Teegarden’s Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0 V),the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES.Aims.As part of the CARMENES search for exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements of Teegarden’sStar and analysed them for planetary signals.Methods.We find periodic variability in the radial velocities of Teegarden’s Star. We also studied photometric measurements to rule out stellarbrightness variations mimicking planetary signals.Results.We find evidence for two planet candidates, each with 1.1M⊕minimum mass, orbiting at periods of 4.91 and 11.4 d, respectively. Noevidence for planetary transits could be found in archival and follow-up photometry. Small photometric variability is suggestive of slow rotationand old age.Conclusions.The two planets are among the lowest-mass planets discovered so far, and they are the first Earth-mass planets around an ultra-cooldwarf for which the masses have been determined using radial velocities.We thank the referee Rodrigo Díaz for a careful review andhelpful comments. M.Z. acknowledges support from the Deutsche Forschungs-gemeinschaft under DFG RE 1664/12-1 and Research Unit FOR2544 “BluePlanets around Red Stars”, project no. RE 1664/14-1. CARMENES isan instrument for the Centro Astronómico Hispano-Alemán de Calar Alto(CAHA, Almería, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de InvestigacionesCientíficas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, LandessternwarteKönigstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen,Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg,Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astro-biología and Centro Astronómico Hispano-Alemán), with additional contribu-tions by the Spanish Ministry of Economy, the German Science Foundationthrough the Major Research Instrumentation Programme and DFG ResearchUnit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, thestates of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía.Based on data from the CARMENES data archive at CAB (INTA-CSIC). Thisarticle is based on observations made with the MuSCAT2 instrument, devel-oped by ABC, at Telescopio Carlos Sánchez operated on the island of Tener-ife by the IAC in the Spanish Observatorio del Teide. Data were partly col-lected with the 150-cm and 90-cm telescopes at the Sierra Nevada Observa-tory (SNO) operated by the Instituto de Astrofísica de Andalucía (IAA-CSIC).Data were partly obtained with the MONET/South telescope of the MOnitoringNEtwork of Telescopes, funded by the Alfried Krupp von Bohlen und HalbachFoundation, Essen, and operated by the Georg-August-Universität Göttingen,the McDonald Observatory of the University of Texas at Austin, and the SouthAfrican Astronomical Observatory. We acknowledge financial support from theSpanish Agencia Estatal de Investigación of the Ministerio de Ciencia, Inno-vación y Universidades and the European FEDER/ERF funds through projectsAYA2015-69350-C3-2-P, AYA2016-79425-C3-1/2/3-P, AYA2018-84089, BES-2017-080769, BES-2017-082610, ESP2015-65712-C5-5-R, ESP2016-80435-C2-1/2-R, ESP2017-87143-R, ESP2017-87676-2-2, ESP2017-87676-C5-1/2/5-R, FPU15/01476, RYC-2012-09913, the Centre of Excellence ”Severo Ochoa”and ”María de Maeztu” awards to the Instituto de Astrofísica de Canarias (SEV-2015-0548), Instituto de Astrofísica de Andalucía (SEV-2017-0709), and Cen-tro de Astrobiología (MDM-2017-0737), the Generalitat de Catalunya throughCERCA programme”, the Deutsches Zentrum für Luft- und Raumfahrt throughgrants 50OW0204 and 50OO1501, the European Research Council through grant694513, the Italian Ministero dell’instruzione, dell’università de della ricerca andUniversità degli Studi di Roma Tor Vergata through FFABR 2017 and “Mis-sion: Sustainability 2016”, the UK Science and Technology Facilities Council through grant ST/P000592/1, the Israel Science Foundation through grant848/16, the Chilean CONICYT-FONDECYT through grant 3180405, the Mexi-can CONACYT through grant CVU 448248, the JSPS KAKENHI through grantsJP18H01265 and 18H05439, and the JST PRESTO through grant JPMJPR1775
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