4,533 research outputs found

    Rehabilitación de estructuras de hormigón: técnicas y sistemas

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    Macaronichnus ‘co-occurrence’ in offshore transition settings: Discussing the role of tidal versus fluid muds influence

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    We thank the Associate-Editor, Emmanuel Fara, and the reviewer, Alfred Uchman, for their detailed and useful comments that significantly contributed to improve the manuscript. This research was funded by Grants PID2019-104625RB-100 funded by MCIN/AEI/10.13039/501100011033, and Grants BRNM-072-UGR18, A-RNM-368-UGR20 and P18-RT-4074 funded by Consejería de Universidad, Investigación e Innovación and by “ERDF A way of making Europe”. Research Group RNM178 (Junta de Andalucía), as well as the “Ichnology and Paleoenvironmental Research Group” (UGR). Funding for open access charge: Universidad de Granada / CBUA.Macaronichnus is a key trace fossil in palaeoceanographic, palaeoclimatic, and petroleum exploration research. Small ichnosubspecies such as Macaronichnus segregatis segregatis, M. s. lineiformins, M. s. maeandriformis and M. s. spiriformis, typically occur in wave-dominated foreshore sands where large M. s. degiberti was never found. The latter shows a wide environmental distribution, occurring in sandy deposits of tidal channels, tidal bar sand sandridges, tidal-flat sand sheets, shorefaces, bioturbated sandy shelf, shelf storm-sheets, shelf sand ridges, and upper slopes. Small M. segregatis and large M. s. degiberti have not been observed to date due the ecological segregation of the tracemakers. An abundant record of large M. s. degiberti in a Tortonian (Late Miocene) mixed carbonate-siliciclastic unit from the Betic Cordillera (southern Spain) has been studied. Occurrence of M. s. degiberti is the result of the interaction of tidal and waves, storm influenced environment determining high-energy conditions and associated palaeoenvironmental parameters as shifting substrates, organic matter availability, and oxygenated pore and bottom-waters. Locally, associated to M. s. degiberti appear small, sinuous traces infilled by light material that were originally assigned to M. s. maeandriformis, and very rare M. s. spiriformis. However, the absence of the typical rim of Macaronichnus avoid a conclusive assignment. The coexistence of both small traces (?M. s. maeandriformis) and large M. s. degiberti is identified in the deposits underlying mudstone layers, revealing the importance of mud deposition during tidal slack water intervals or linked to fluid mud events favouring the co-occurrence of the trace makers of both Macaronichnus ichnosubespecies. This fact would have significant palaeobiological and palaeoecological implications, and could be the first record of both ichnosubspecies in the same intervals.MCIN/AEI/10.13039/501100011033: PID2019-104625RB-100Consejería de Universidad, Investigación e Innovación BRNM-072-UGR18, A-RNM-368-UGR20, P18-RT-4074“ERDF A way of making Europe”Junta de Andalucía: Research Group RNM178“Ichnology and Paleoenvironmental Research Group” (UGR)Universidad de Granada / CBU

    The wage gap between immigrant and native workers in Spain: an analysis using matched employer-employee data

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    The fact that Spain has witnessed a sharp increase in the number of immigrants over the past decade has generated considerable interest, particularly as regards wages earned by immigrants in host industries. We analyze whether controlling for both observable and unobservable characteristics of employers —in addition to individual variables and the economic context— makes any difference as regards the debate regarding the existence of wage differences between immigrant and native workers in Spain. As we show, doing this considerably reduces (or even eliminates) the inequalities found in previous research, thereby questioning the results attained by previous studies on this issue.Immigration, salaries, assimilation.

    Academic achievement in sciences: the role of preferences and educative assets

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    This paper provides new evidence on the effect of pupil´s self-motivation andacademic assets allocation on the academic achievement in sciences acrosscountries. By using the Programme for International Student Assessment 2006 (PISA2006) test we find that both explanatory variables have a positive effect onstudent´s performance. Self-motivation is measured through an instrumentthat allows us to avoid possible endogeneity problems. Quantile regression isused for analyzing the existence of different estimated coefficients over thedistribution. It is found that both variables have different effect on academicperformance depending on the pupil´s score. These findings support theimportance of designing focalized programs for different populations,especially in terms of access to information and communication technologiessuch as internet.PISA, self-motivation, academic assets, academic achievement, Quantile regression

    Médico, traductor, inventor: Miguel de Luna, Cristiano arábigo de Granada".

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    [ES] El morisco Miguel de Luna es conocido, principalmente, por ser el autor de la Verdadera historia del Rey don Rodrigo y por su intervención, como traductor y posible coautor, en la falsifi cación de los Libros Plúmbeos del Sacromonte. En este artículo aportamos nueva documentación sobre su trayectoria biográfi ca y sobre sus actividades: realizamos una edición y estudio de su tratado Sobre la conveniencia de restaurar los baños y estufas, y un análisis de su participación en el asunto del aparecimiento de la Santa Vera Cruz de Caravaca; recogemos, además, material novedoso sobre su participación en las falsifi caciones granadinas. Todo ello conforma un perfi l coherente de la fi gura de Miguel de Luna, no como un criptomusulmán, sino como “cristiano arábigo”, que intenta desislamizar la herencia cultural y lingüística árabe para conseguir integrarla en la sociedad española de su época.[EN] The Morisco Miguel de Luna is known mainly as the author of the book La verdadera historia del Rey Don Rodrigo and by his participation as translator and possible co-author, of the forgeries known as the Lead Books of the Sacromonte. In this article we provide new documents for his biography and his activities, specially his treaty on the use of baths and his participation in the affair of the Santa Vera Cruz de Caravaca. We also provide new documents on his role in the Sacromonte affair. The whole conforms a new profi le of Miguel de Luna not as a crypto-muslim Morisco but as a Christian Arabic, someone who endeavours to de-islamize the Arabic heritage, both in its linguistic and cultural aspects, to include it and make it acceptable in the Spanish society of his time.Peer reviewe

    Biosensors Platform Based on Chitosan/AuNPs/Phthalocyanine Composite Films for the Electrochemical Detection of Catechol. The Role of the Surface Structure

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    Producción CientíficaBiosensor platforms consisting of layer by layer films combining materials with different functionalities have been developed and used to obtain improved catechol biosensors. Tyrosinase (Tyr) or laccase (Lac) were deposited onto LbL films formed by layers of a cationic linker (chitosan, CHI) alternating with layers of anionic electrocatalytic materials (sulfonated copper phthalocyanine, CuPcS or gold nanoparticles, AuNP). Films with different layer structures were successfully formed. Characterization of surface roughness and porosity was carried out using AFM. Electrochemical responses towards catechol showed that the LbL composites efficiently improved the electron transfer path between Tyr or Lac and the electrode surface, producing an increase in the intensity over the response in the absence of the LbL platform. LbL structures with higher roughness and pore size facilitated the diffusion of catechol, resulting in lower LODs. The [(CHI)-(AuNP)-(CHI)-(CuPcS)]2-Tyr showed an LOD of 8.55∙10−4 μM, which was one order of magnitude lower than the 9.55·10−3 µM obtained with [(CHI)-(CuPcS)-(CHI)-(AuNP)]2-Tyr, and two orders of magnitude lower than the obtained with other nanostructured platforms. It can be concluded that the combination of adequate materials with complementary activity and the control of the structure of the platform is an excellent strategy to obtain biosensors with improved performances.Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (project RTI2018-097990-B-100)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA275P18)Infraestructuras Red de Castilla y León (grant UVA01
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