186 research outputs found

    Differences in n-type doping efficiency between Al- and Ga-ZnO films

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    A careful and wide comparison between Al and Ga as substitutional dopants in the ZnO wurtzite structure is presented. Both cations behave as n-type dopants and their inclusion improves the optical and electrical properties of the ZnO matrix, making it more transparent in the visible range and rising up its electrical conductivity. However, the same dopant/Zn ratio leads to a very different doping efficiency when comparing Al and Ga, being the Ga cation a more effective dopant of the ZnO film. The measured differences between Al- and Ga-doped films are explained with the hypothesis that different quantities of these dopant cations are able to enter substitutionally in the ZnO matrix. Ga cations seem to behave as perfect substitutional dopants, while Al cation might occupy either substitutional or interstitial sites. Moreover, the subsequent charge balance after doping appear to be related with the formation of different intrinsic defects that depends on the dopant cation. The knowledge of the doped-ZnO films microstructure is a crucial step to optimize the deposition of transparent conducting electrodes for solar cells, displays, and other photoelectronic devices.Ministerio de Ciencia e Innovación TEC2007-60996, MAT2008-06858-C02-02, MAT2008- 06330, TEC2010-16700FUNCOAT CSD2008-00023- CONSOLIDER INGENIOSonderforschungsbereich SFB 76

    Chloride Nutrition Regulates development, Water Balance and Drought Resistance in Plants

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    6 páginas.-- 5 figuras.-- 9 referencias.-- Poster presentado en el XII Luso-Spanish Symposium on Plant Water Relations – Water to Feed the World. 30th of September – 3rd of October (Evora) PortugalCl- is a strange micronutrient since actual Cl- concentration in plants is about two orders of magnitude higher than the content required as essential micronutrient. This accumulation requires a high cost of energy, and since Cl- is a major osmotically active solute in the vacuole, we propose that Cl- plays a role in the regulation of water balance in plants. We show here that, when accumulated to macronutrient levels, Cl- specifically regulates leaf cell elongation and water balance parameters, improving water relations at both the leaf tissue and the whole plant levels, increasing drought resistance in higher plants.This work was supported by the Spanish Ministry of Science and Innovation-FEDER grant AGL2009-08339/AGR.Peer Reviewe

    Evolution of the Quorum network and the mobilome (plasmids and bacteriophages) in clinical strains of Acinetobacter baumannii during a decade

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    In this study, we compared eighteen clinical strains of A. baumannii belonging to the ST-2 clone and isolated from patients in the same intensive care unit (ICU) in 2000 (9 strains referred to collectively as Ab_GEIH-2000) and 2010 (9 strains referred to collectively as Ab_GEIH-2010), during the GEIH-REIPI project (Umbrella BioProject PRJNA422585). We observed two main molecular differences between the Ab_GEIH-2010 and the Ab_GEIH-2000 collections, acquired over the course of the decade long sampling interval and involving the mobilome: i) a plasmid harbouring genes for blaOXA 24/40 ss-lactamase and abKA/abkB proteins of a toxin-antitoxin system; and ii) two temperate bacteriophages, Ab105-1varphi (63 proteins) and Ab105-2varphi (93 proteins), containing important viral defence proteins. Moreover, all Ab_GEIH-2010 strains contained a Quorum functional network of Quorum Sensing (QS) and Quorum Quenching (QQ) mechanisms, including a new QQ enzyme, AidA, which acts as a bacterial defence mechanism against the exogenous 3-oxo-C12-HSL. Interestingly, the infective capacity of the bacteriophages isolated in this study (Ab105-1varphi and Ab105-2varphi) was higher in the Ab_GEIH-2010 strains (carrying a functional Quorum network) than in the Ab_GEIH-2000 strains (carrying a deficient Quorum network), in which the bacteriophages showed little or no infectivity. This is the first study about the evolution of the Quorum network and the mobilome in clinical strains of Acinetobacter baumannii during a decade

    Genomic Evolution of Two Acinetobacter baumannii Clinical Strains from ST-2 Clones Isolated in 2000 and 2010 (ST-2_clon_2000 and ST-2_clon_2010)

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    Acinetobacter baumannii is a successful nosocomial pathogen due to its ability to persist in hospital environments by acquiring mobile elements such as transposons, plasmids, and phages. In this study, we compared two genomes of A. baumannii clinical strains isolated in 2000 (ST-2_clon_2000) and 2010 (ST-2_clon_2010) from GenBank project PRJNA308422

    Estilos de vida en estudiantes del área de la salud de Bucaramanga

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    ABSTRACT: In this study, the lifestyles of 378 health care students from Bucaramanga city were examined. Four analytical dimensions were considered: exercise and physical activity; alcohol consumption; smoking and psychoactive substances use; and sexuality. The research concludes that consistent with previous studies the possession of knowledge, adequate health beliefs, and motivations towards healthy practices are insufficient for the adoption of healthy behaviors. A larger exploratory study that addresses the reasons for the inconsistencies between beliefs and motivations versus healthy practices is required.RESUMEN: En el presente estudio se evaluaron los estilos de vida de 378 estudiantes del área de la salud residentes en la ciudad de Bucaramanga. Se estudiaron cuatro dimensiones analíticas: ejercicio y actividad física; consumo de alcohol; consumo de cigarrillo y sustancias psicoactivas; y la sexualidad. La investigación concluyó que, acorde con estudios previos, la posesión de conocimiento no es suficiente para la adopción de conductas saludables, así como tampoco lo son el disponer de creencias adecuadas sobre la salud o de motivaciones consistentes frente a la práctica saludable. Se requiere un estudio explicativo de mayor envergadura que aborde las razones de las incongruencias entre las creencias y las motivaciones frente a las prácticas saludables.

    El álbum poético en portugués y en español: sinergia estética entre palabras e ilustraciones

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    Este estudo procurou problematizar a relação textual que se observa entre a palavra e a imagem em um tipo de texto especialmente concebido para crianças: o álbum poético. Para tal, utilizamos alguns exemplos textuais significativos desse subgênero literário/editorial ainda em emergência tanto em Portugal quanto na Espanha, e propusemos uma definição e uma caracterização baseadas no comentário de sequências poéticas nas quais a ilustração sustenta o conteúdo verbal. Efetivamente, centrando a atenção no álbum poético de potencial recepção infanto-juvenil, sugere-se uma análise de diversos títulos de autoria portuguesa e espanhola, assente em uma leitura dialógica do texto verbal e do visual. A sinergia que se concretiza entre as duas componentes enunciadas alicerça essa nova construção estética que tem, na verdade e na sua essência, a poesia como matriz e, em larga medida, é devedora dos efeitos expressivos da metáfora.This study aimed to discuss the relation between words and images in a type of text especially directed to children: the picture-poetry book. From significant examples of this literary subgenre still emerging in both Portugal and Spain, we propose a definition and characterization based on the review of poetic sequences in which illustrations support the verbal content. By focusing on picture-poetry books potentially aimed for adolescents and children, we present an analysis of several titles by Portuguese and Spanish authors, based on the dialogic reading between verbal and visual texts. The synergy found between these two components creates de foundantions of a new aesthetic construction which, in truth and in essence, has poetry as its matrix and owes its expressive effects to metaphors.Este estudio ha tenido como objetivo discutir la relación textual que existe entre la palabra y la imagen en un tipo texto especialmente creado para niños: el álbum poético. Para ello, utilizamos algunos ejemplos textuales significativos de un subgénero literario en emergencia tanto en Portugal cuanto en España, y hemos propuesto una definición de este subgénero y su caracterización a partir del comentario de secuencias poéticas en las cuales la imagen sustenta el contenido verbal. De hecho, centrando la atención en el álbum poético de potencial recepción infantil y juvenil, proponemos un análisis de diversos títulos de autoría portuguesa y española basado en la lectura dialógica entre el texto verbal y el texto ilustrativo. La sinergia que se establece entre estos dos componentes enunciados facilita una nueva construcción estética que da pie, en su esencia, a un tipo de poesía que, en gran medida, es deudora de los efectos expresivos de la metáfora.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), Portugal. Fundos Nacionais através da FCT (Fundação para a Ciência e a Tecnologia) e cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) no âmbito do CIEC (Centro de Investigação em Estudos da Criança, da Universidade do Minho) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

    Submarine canyons and related features in the Alboran Sea: continental margins and major isolated reliefs

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    The analysis of a data set of multibeam bathymetry plus high resolution seismic and parametric profiles allow us to characterize the geomorphologic units on the Alboran Sea-floor as well as the evolution of morpho-sedimentary systems along the Pliocene and Quaternary, later than the main erosive Messinian event. Since the opening of the Gibraltar Straits, the sedimentary evolution of this basin has been controlled by the interchange of water masses between the Atlantic Ocean and the Mediterranean Sea. Basin physiography is also a consequence of the Pliocene-Quaternary compression which has progressively uplifted the sourrounding reliefs and deforms the interior and the margins of the basin. On this scenario, several submarine canyons and gullies have been developed in this basin which traverse especially the northern margin and the flanks of the Northern Alboran Ridge, without affecting the African margins. This fact must be related to the action of bottom contour currents which constitute the main morpho-sedimentary process. The influence of water masses distributed the sedimentary input carried by rivers and coming from the erosion of surrounding ranges. In the southern margin of this basin this influence is stronger and inhibits the development of transversal submarine canyons

    Miniatures from domestic contexts in Iron age Iberia

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    This article reviews a set of miniatures from domestic contexts in Iron Age eastern Iberia, and interprets them in terms of their role in forging social personae. After an introduction to the historical case under consideration, the miniatures are described in terms of their typology and their contexts of provenance are outlined. Though not abundant, they tend to occur in central places in the landscape; specifically, they are often found in houses of the powerful. The vast majority are miniatures of pottery and tools, though some miniature weapons are recorded. We contend that these objects were used as a means of enculturation and for the learning of values and norms. It is no coincidence that they emerge in the archaeological record of Iron Age Iberia at the same time as the rise of a social structure based on hereditary power

    Análisis de seguridad y productividad del suministro de energía eléctrica en el sistema eléctrico de Nicaragua en el periodo comprendido desde el año 2010 hasta el 2018

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    The purpose of this study was to study the safety and productivity of power supply in the electrical system of Nicaragua in the period from 2010 to 2018 using the Stirling pointer, reserve margin, loss indicator largest generator, the market concentration indicator and methodological data envelopment analysis tool (DEA) and Malmquist indices. The behavior of the energy sector in Nicaragua, in the period studied 2005 - 2013. As result, an indicator from Stirling index ware obtained, right now Nicaragua has security in the electrical system. The reserve margin indicator was obtained as a result, of the safety level from the point of evaluation of this indicator the system has enough security to avoid incurring damages to final consumers, as a result of the loss of the largest generator indicator (LU), concludes that it has a secure system. Moreover, the rate of market concentration showed that Nicaragua does not have a competitive energy market. In assessing productivity use of energy resources, it ware found that, only the use of biomass has an average annual rate of productivity growth.Rev. iberoam. bioecon. cambio clim. Vol. 1 num 2, 2015, pág. 20-52El propósito de este estudio fue el de estudiar la seguridad y productividad del suministro de energía eléctrica en el sistema eléctrico de Nicaragua en el periodo desde el año 2010 hasta el 2018 utilizando el Indicador Stirling, indicador margen de reserva, indicador pérdida del mayor generador, el indicador de concentración de mercado y herramienta metodológica de análisis envolvente de datos (DEA) y los índices de Malmquist. Se estudió el comportamiento del sector energético de Nicaragua, en el periodo 2005 – 2013. Como resultado del indicador Stirling se obtuvo, que Nicaragua en estos momentos cuenta con seguridad en el sistema eléctrico, Del indicador margen de reserva se obtuvo como resultado, que el nivel de seguridad desde el punto de evaluación de este indicador el sistema cuenta con la suficiente seguridad como para no incurrir en afectaciones a los consumidores finales, Como resultado del indicador pérdida del mayor generador (LU), concluye en que se posee un sistema seguro. Por otra parte, El índice de concentración de mercado mostro que Nicaragua no posee un mercado energético competitivo. En la evaluación de productividad del uso de recursos energéticos se encontró que solo el uso de biomasa presenta un ritmo promedio anual de crecimiento de productividad.Rev. iberoam. bioecon. cambio clim. Vol. 1 num 2, 2015, pág. 20-5
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