182 research outputs found

    Mussel shell mortars durability: Study of aggregate replacement limit

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    [Abstract]: The knowledge acquired through previous experimental phases with coating mortars with mussel shell aggregates led to conclude that irregular, flaky and hydrophobic particles of the mussel shell and the organic matter content introduce entrapped air and entrained air in the mixes. This phenomenon causes different and opposite effects on the main properties of mortars, which are in some way positive and negative (for durability), consequently, their durability cannot be easily predicted. The present work pretends to analyse the results of different durability tests, such as water vapour permeability, adhesive strength, and weathering cycles to recommend the maximum percentage of mussel shell sand used in coating mortars that guarantee the required lifespan. After an in-depth literature review, it can be said that it is not easy to predict the durability of mortars using mussel shell aggregates. This question has been hardly analysed in the existing literature and the maximum substitution percentage of conventional aggregate that can be replaced is not clear. This work aims to answer this issue by analysing different properties: water vapour permeability, adhesive strength, and weathering cycles. Mussel shell content improves the water vapour permeability of both air lime and cement mortars but worsens the adhesive strength and weathering cycle behaviour. For most applications, 25 % of mussel shell aggregate can be employed, but for some applications, 50 % or even 75 % of mussel shell aggregate is feasible and will avoid the undesirable landfilling of this waste.This work has been developed within the framework of the project "Valorización de las conchas de bivalvos gallegos en el ámbito de la construcción" (Valorisation of Galician bivalve shell in the construction sector; Code 00064742/ITC-20133094), funded by CDTI (Centro para el Desarrollo Tecnológico e Industrial) under the FEDER-Innterconecta Program, and co-financed with European Union ERDF funds

    Episodic and semantic autobiographical memory in temporal lobe epilepsy

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    Autobiographical memory (AM) is understood as the retrieval of personal experiences that occurred in specific time and space. To date, there is no consensus on the role of medial temporal lobe structures in AM. Therefore, we investigated AM in medial temporal lobe epilepsy (TLE) patients. Twenty TLE patients candidates for surgical treatment, 10 right (RTLE) and 10 left (LTLE), and 20 healthy controls were examined with a version of the Autobiographical Interview adapted to Spanish language. Episodic and semantic AM were analyzed during five life periods through two conditions: recall and specific probe. AM scores were compared with clinical and cognitive data. TLE patients showed lower performance in episodic AM than healthy controls, being significantly worst in RTLE group and after specific probe. In relation to semantic AM, LTLE retrieved higher amount of total semantic details compared to controls during recall, but not after specific probe. No significant differences were found between RTLE and LTLE, but a trend towards poorer performance in RTLE group was found. TLE patients obtained lower scores for adolescence period memories after specific probe. Our findings support the idea that the right hippocampus would play a more important role in episodic retrieval than the left, regardless of a temporal gradient.Fil: Múnera Martínez, Claudia Patricia. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Lomlomdjian, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Gori, María Belén. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Terpiluk, Veronica. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Medel, Nancy Ruth. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Solis, Patricia. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Kochen, Sara Silvia. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; Argentin

    The effects of native shrub, fencing, and acorn size on the emergence of contrasting co-occurring oak in Mediterranean grazed areas

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    Producción CientíficaResearch Highlights: The regeneration of Quercus species is usually very difficult in many oak woodlands transformed by livestock farming. Some studies have reported that shrubs can facilitate regeneration. However, the strength of interaction may vary depending on, among other factors, the shrub species and the stress tolerance of the oak species. Moreover, further studies are necessary to clarify the relative importance of the two facilitation mechanisms in the same community. Background and Objectives: Cytisus multiflorus (L’Her.) Sweet is a predominant shrub species in the Mediterranean grazed open-oak-woodlands found in the central west of the Iberian Peninsula (bioclimatic limit) and is present with Quercus pyrenaicaWilld and Quercus ilex subsp. ballota Samp trees. Thus, we assessed the effect of these native shrubs and acorn size, and the effect of excluding large herbivores, on the seedling emergence of two contrasting co-occurring Quercus species under a bioclimatic limit. Materials and Methods: A manipulative field experiment was carried out considering four treatments as a combination of shrubs (shrub/no-shrub) and fence (fenced/open) factors. A total of twenty plots, five replicates for each treatment were available. In each plot, 20 acorns were sown: 10 acorns (5 small and 5 large) for each Quercus species. Acorn emergence was recorded during the first four years following the sowing. Results: Seedling emergence took place mostly in the spring of the first year after sowing. The presence of shrub was the main significant factor and incremented the emergence of both Q. ilex and Q. pyrenaica. The effect of the fence depended on the Quercus species considered, improving only the emergence of Q. pyrenaica. A negative effect with the small acorns was detected but only for Q. pyrenaica. In all treatments, Q. ilex emerged more than Q. pyrenaica. Conclusions: C. multiflorus had a clear facilitative effect on the seedling emergence of Q. ilex and Q. pyrenaica, which was much greater than the physical effect that acorn size and excluding large herbivores had. As such, this native shrub may have a key role in oak regeneration in Mediterranean grazed areas. Furthermore, in these areas of contact between marcescent and sclerophyllous Quercus species, Q. ilex currently emerges more than Q. pyrenaica. This could be indicative of a shift towards more xeric climatic conditions, which could lead to a change in the dominant tree species in the future. However, this change could be modulated by the effects of native shrub and large herbivores.Junta de Castilla y León - (Project SA013G19)Universidad de Salamanca - (Programa de financiación de grupos de investigación (2014/00165/001)

    Análisis de las estrategias de comunicación política de Jorge Yunda durante la campaña electoral 2019 a la alcaldía de Quito en la plataforma twitter.

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    El artículo analiza las estrategias de comunicación política de Jorge Yunda en Twitter en el período de campaña electoral para la alcaldía de Quito en 2019, a partir de una evaluación al empleo de los distintos recursos disponibles en esta red y de la identificación del uso del lenguaje, discursos y narrativas de los tweets. Tras ese interés se revisaron los fundamentos teóricos sobre las estrategias de comunicación política en contiendas electorales y el rol de las redes sociales en estos eventos. Se realizó una investigación cualitativa, descriptiva y exploratoria donde se estudiaron 129 tweets publicados en las cuentas @LoroHomero y @PanasJorgeYunda. El análisis del discurso de estos mensajes permitió responder los objetivos de investigación y concluir que la estrategia seguida por Jorge Yunda durante la campaña por la alcaldía de Quito es coherente con la evolución de la comunicación política en tiempos de desarrollo tecnológico. Twitter se explotó como plataforma para construir y dar a conocer la imagen de un candidato por la alcaldía de Quito que de manera simbólica revitalizaba el sur de la ciudad y a los excluidos. La construcción de esta imagen fue esencial para generar un discurso que atrajera al electorado quiteño en un contexto de alta polarización. Sin embargo, el candidato no recurrió a esta estrategia discursiva de denigrar al adversario y desechó la violencia política. La campaña se enfocó hacia el uso estratégico de las cuentas en Twitter para comunicar ideas políticas y programáticas, así como para personalizar y humanizar al candidato.The article analyzes Jorge Yunda's political communication strategies on Twitter during the period of the electoral campaign for the mayor of Quito in 2019, based on an evaluation of the use of the different resources available on this network and the identification of the use of language, speeches and narratives in the tweets. Following this interest, the theoretical foundations of political communication strategies in electoral contests and the role of social networks in these events were reviewed. A qualitative, descriptive and exploratory research was carried out where 129 tweets published in the accounts @LoroHomero and @PanasJorgeYunda. The analysis of the discourse of these messages allowed us to respond to the research objectives and conclude that the strategy followed by Jorge Yunda during the campaign for the Municipality of Quito is coherent with the evolution of political communication in times of technological development. Twitter was used as a platform to build and publicize the image of a candidate for mayor of Quito that symbolically revitalized the south of the city and the excluded. The construction of this image was essential to generate a discourse that would attract the Quito electorate in a context of high polarization. However, the candidate did not resort to this discursive strategy of denigrating the adversary and dismissed political violence. The campaign focused on the strategic use of Twitter accounts to communicate political and programmatic ideas, as well as to personalize and humanize the candidate

    The Effects of Native Shrub, Fencing, and Acorn Size on the Emergence of Contrasting Co-Occurring Oak in Mediterranean Grazed Areas

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    [ENG]Research Highlights: The regeneration of Quercus species is usually very difficult in many oak woodlands transformed by livestock farming. Some studies have reported that shrubs can facilitate regeneration. However, the strength of interaction may vary depending on, among other factors, the shrub species and the stress tolerance of the oak species. Moreover, further studies are necessary to clarify the relative importance of the two facilitation mechanisms in the same community. Background and Objectives: Cytisus multiflorus (L’Her.) Sweet is a predominant shrub species in the Mediterranean grazed open-oak-woodlands found in the central west of the Iberian Peninsula (bioclimatic limit) and is present with Quercus pyrenaicaWilld and Quercus ilex subsp. ballota Samp trees. Thus, we assessed the effect of these native shrubs and acorn size, and the effect of excluding large herbivores, on the seedling emergence of two contrasting co-occurring Quercus species under a bioclimatic limit. Materials and Methods: A manipulative field experiment was carried out considering four treatments as a combination of shrubs (shrub/no-shrub) and fence (fenced/open) factors. A total of twenty plots, five replicates for each treatment were available. In each plot, 20 acorns were sown: 10 acorns (5 small and 5 large) for each Quercus species. Acorn emergence was recorded during the first four years following the sowing. Results: Seedling emergence took place mostly in the spring of the first year after sowing. The presence of shrub was the main significant factor and incremented the emergence of both Q. ilex and Q. pyrenaica. The effect of the fence depended on the Quercus species considered, improving only the emergence of Q. pyrenaica. A negative effect with the small acorns was detected but only for Q. pyrenaica. In all treatments, Q. ilex emerged more than Q. pyrenaica. Conclusions: C. multiflorus had a clear facilitative effect on the seedling emergence of Q. ilex and Q. pyrenaica, which was much greater than the physical effect that acorn size and excluding large herbivores had. As such, this native shrub may have a key role in oak regeneration in Mediterranean grazed areas. Furthermore, in these areas of contact between marcescent and sclerophyllous Quercus species, Q. ilex currently emerges more than Q. pyrenaica. This could be indicative of a shift towards more xeric climatic conditions, which could lead to a change in the dominant tree species in the future. However, this change could be modulated by the effects of native shrub and large herbivores

    Effect of the forest-mine boundary form on woody colonization and forest expansion in degraded ecosystems

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    [ENG]We evaluated the ecological significance of the boundary form between two patches with contrasting vegetation (mine grassland and adjacent forest) on woody colonization and forest expansion in open-cast coal mines in Northern Spain. Woody colonization and browsing traces were measured on three mine sites, along 24 transects that were laid out perpendicular to the forest-mine boundary and classified according to their shape (concave, convex, straight). Mine sites were colonized from the close forest by woody species, whose colonization intensity depends on the boundary form. The overall colonization intensity decreased with increasing distance to the forest and differed depending on the boundary form. The more intense colonization was found in concave boundaries and the strongest decrease in convex boundaries close to the forest, whereas straight boundaries showed an intermediate colonization pattern. Concave boundaries reached higher woody cover in the basal strata of the mines than convex (up to 2 m) or straight boundaries (up to 1 m) from 11 m to the forest edge, mainly by the presence of dense patches of Cytisus scoparius (L.) Link, with a scattered overstory of Genista florida L. These shrubs might reduce the browsing intensity and act as nurse plants facilitating the establishment of Quercus petraea (Matt.) Liebl. in mine areas at greater distances from the forest edge. The forest-mine boundary form does not affect the forest vertical structure that is homogenous and does not help explain the woody colonization pattern in the mines. We conclude that edge characteristics have a strong potential to be used in the restoration of native forests based on natural processes. The implications of our results for sessile oak (Quercus petraea (Matt.) Liebl.) forest expansion along edges in fragmented Mediterranean forest landscapes were discussed

    Main crustal seismic sources in El Salvador

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    We present a map and a data set containing information about intra-plate seismic sources in El Salvador. These are the results of the field campaigns and data analysis carried out by the research group of Planetary Geodinamics, Active Tectonics and Related Risks from Complutense University of Madrid during the last 12 years. We include two maps, the first map contains 1405 fault traces with evidences of Quaternary activity derived form morphometric, paleoseismological and geomorphological analysis together with field data mapping carried in El Salvador. The second map is a synthesis of the 29 intra-plate seismic sources selected from the quaternary faults map. The geometry of these sources was simplified and we also include a table where some available data of the proposed sources are included, such as their name, orientation, length and slip-rate. For further interpretation and discussion of these sources see (Alonso-Henar et al., 2018) [1, doi.org/10.1016/j.enggeo.2018.06.015]This research was supported by the project“ QUAKESTEP”(CGL2017–83931-C3-1-P) founded by the Spanish Ministry of Science, Innovation and Universities. We are grateful to our colleagues atDGOA-MARN (Observatorio Ambiental del Ministerio de Medio Ambiente y Recursos Naturales de ElSalvador): Manuel Díaz, Walter Hernandez and Douglas Hernández for their assistance. Figures were produced using GMT softwar

    Validación de escala de satisfacción con el parto (ESP)

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    46 p.Este estudio desarrolló una escala de satisfacción materna con el parto (ESP) en español aportando múltiples indicadores de fiabilidad y validez. Los ítems fueron creados utilizando técnicas deductivas basadas en escalas y teorías revisadas en la literatura científica. Se crearon los ítems tras la revisión y completaron con valoración técnica de expertos en psicometría. Para el desarrollo deductivo del instrumento, se utilizó: (a) la base teórica del modelo de Calidad Percibida de Brady y Cronin (2011), con 3 factores específicos: atención del personal, infraestructura y servicios; y (b) Diferentes escalas de satisfacción con el parto (BSS-R, SMMS, NSNS, MCRS, BirthMARQ y la BMSP). Junto con el instrumento desarrollado se administró la escala de Depresión PHQ-9 con el objetivo de obtener índices de validez predictiva. Un total de 459 mujeres de la Región del Maule participaron de forma voluntaria y anónima a este estudio. Los resultados mostraron adecuados índices de fiabilidad (α = 0.92-0.99; ω = 0.94-0.96), de validez (correlaciones significativas, pruebas de Barlett significativas, KMO = 0.824-0.952 y factores unidimensionales determinados por análisis paralelo) y un buen ajuste del modelo estructural considerando todas las variables del estudio (CFI = 0.976-0.994; TLI = 0.969-0.985; RMSEA = 0.89-0.122). Palabras claves: Satisfacción materna, calidad percibida, parto, nacimiento, depresión posparto
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