Na+-dependent NO3- uptake in leaf cells of the seagrass Posidonia oceanica (L.) Delile

Posidonia oceanica (L.) Delile is an endemic Mediterranean seagrass of recognized ecological significance and, as other seagrasses, this species has secondarily adapted to live in the marine environment. In this alkaline medium with a high Na+ concentration (0.5 M), the high inwardly directed electrochemical potential gradient for sodium is used in the seagrass Zostera marina to energize the uptake of nitrate1 and phosphate that usually occur at concentration below 10 µM. Here we summarize several evidences for the operation of a sodium-dependent high-affinity nitrate transport system at the plasma membrane of the mesophyll leaf cells of P. oceanica. Leaf cells of P. oceanica possess a H+-ATPase as a primary pump, exhibit a plasma membrane potential (Em) of -174 ± 10 mV and show reduced Na+ permeability. The addition of micromolar nitrate concentrations induces membrane depolarizations that show saturation kinetics. Curve fitting of the values renders a semisaturation constant (Km) of 21.3 ± 6.6 μM and a maximum depolarization (Dmax) of 7 ± 1 mV. In dark conditions, Dmax decreases by fifty percent but no significant effect is observed on the Km value. On the other hand, nitrate induced depolarizations show sodium dependence. The depolarizations induced by 100 µM NO3- in media containing increasing Na+ concentrations (from 0 to 250 mM) show saturation kinetics, rendering a Km value of 16 ± 5 mM Na+. Moreover, the depolarization induced by 100 µM NO3- is accompanied by a simultaneous increase of cytosolic sodium, measured by Na+-sensitive microelectrodes, of 0.4 ± 0.2 mM above the resting cytosolic sodium concentration (17 ± 2 mM). Finally, nitrate uptake rates, measured in depletion experiments, decreases by 50% and 80% in dark conditions and in the absence of Na+, respectively, compared with control conditions (0.5 M Na+ and light). All together, these results strongly suggest that NO3- uptake in P. oceanica leaf cells is mediated by a high-affinity nitrate carrier that uses Na+ as the driving ion. 1 Rubio et al. (2005). J. Exp. Bot, 412: 613-622. Project Funding: CTM 2011-30356. (MEC)Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Innovación en servicios en la UE: una aproximación a la densidad de innovación y la importancia económica de los innovadores a partir de los datos agregados de la CIS3

El objetivo de este trabajo es estudiar el comportamiento que tienen en materia de innovación los diferentes sectores que componen el llamado sector servicios dentro de la Unión Europea, utilizan-do las estadísticas de la tercera encuesta (CIS 3). Ante la imposibilidad de trabajar con los micro-datos se han utilizado los datos sectoriales por países publicados en el informe titulado Innovationin Europe y se ha adoptado un análisis agregado que aborda las diferencias entre países y sectores. Las principales variables explicativas de la innovación en servicios en los dos modelos estimados son las que se refieren al sector y país de pertenencia. La realización de actividades de innovación tecnológica distintas de la I+D, parece favorecer tanto la densidad de innovación como la preemi-nencia económica de los innovadores. Sin embargo, la adopción de acciones estratégicas y de mejo-ras internas (organizativas y de gestión) no muestra ningún efecto positivo. Entre las variables que más inesperado resulta encontrar fuera de las estimaciones destacamos la cooperación, la I+D, las diferentes fuentes de información y los mecanismos de protección. Estos resultados deben ser reto-mados cuando la información micro permita un análisis más detalladoThe aim of this paper is to analyse the behaviour of different service sectors in the EU with regard to innovation. Because of the non availability of micro data, we have used sectoral data in an aggre-gated analysis. The variables which have a higher explanatory power are the sector of activity and the country of origin. To carry out non R&D innovatory activities seems to encourage innovation, albeit the adoption of strategic actions or inner improvements does not show any positive influen-ce. It must be underlined that many other innovatory actions such as cooperation or R&D do not show a significant impact. Some of these results might be retaken into consideration when micro data could allow us to make more detailed analysi

Innovación en servicios en la UE : densidad de innovación y preeminencia económica de los innovadores

En este trabajo estudiamos el comportamiento de la innovación en servicios en la UE, con datos sectoriales por países (CIS 3), mediante un análisis agregado. Las principales variables explicativas son las referidas al sector y país de pertenencia, lo que apunta dependencia de la trayectoria y un patrón norte-sur. Las actividades de innovación distintas de la I+D, se muestran más influyentes que las acciones tradicionales de innovación. Las diferencias entre la densidad de innovación y la preeminencia económica de los innovadores apuntan a una mayor dificultad para generar innovaciones que para explotarlas y otorgan importancia a la capacidad de absorció

Factors affecting innovation revisited

The aim of this paper is to contribute to a better understanding of factors affecting innovation by analysing the Spanish manufacturing sector using microdata of the 2003 Spanish Innovation Survey. To enrich the analysis a self developed sectoral taxonomy is used coming from the combination of both of the sectoral Revealed Technological Advantages (RTA) and worldwide technological dynamism of the sectors; moreover firms are classified according to the type of capital ownership: independent companies, companies belonging to a national group and subsidiaries of multinational enterprises. The abundance and heterogeneity of variables advised us to use Factor analysis to reduce and organise the original variables into a number of consistent and theoretically significant factors. We found differences between product and process innovation, both in number of explicative variables (significant independent variables) and in relative effect of independent variables (even, in some cases, a sign change from product to process innovation). Taxonomy matters because of some differences in explanatory (independent) variables for each sector and model explanatory power differences between sectors, and, on the other hand, because of the “non significance” of some significant variables once we control by sectoral taxonomyEl propósito de este trabajo es contribuir a un mejor conocimiento de los factores que afectan a la innovación mediante el análisis de los microdatos de la encuesta de innovación de las empresas españolas de 2003. El estudio se aborda desde la elaboración de una taxonomía de sectores combinando las Ventajas Tecnológicas Reveladas de la industria española con el dinamismo tecnológico mundial; además se introduce una clasificación de las empresas en función de la pertenencia o no a un grupo de empresas y de si esos grupos son de nacionalidad española o extranjera. Se utilizan técnicas de Análisis Factorial para reducir y organizar la abundante información disponible en Factores con significado económico que después son empleados como variables explicativas de la innovación de producto y de proceso. Se encuentran diferencias entre ambos tipos de innovación tanto por el número de factores significativos como en la intensidad de su capacidad explicativa. La taxonomía elaborada muestra su importancia al mostrar patrones de comportamiento distintos entre los cuatro tipos de casos construido

Viajes a Francia para el estudio de la Química, 1770 y 1833

[email protected] viajes científicos a Francia durante último tercio del siglo XVIII y el primero del siglo XIX son generalmente considerados, por diversas razones, como una importante cuestión en el desarrollo de la ciencia española de ese período. Los viajes científicos de los pensionados y comisionados de la Ilustración suelen estudiarse como un vehículo de transmisión de nuevas ideas científicas. Por el contrario, el exilio de autores afrancesados y liberales suele valorarse negativamente, como una de las causas de la decadencia de la ciencia española del primer tercio del siglo XIX. En este trabajo se pretende ofrecer un marco general para el estudio de estos viajes y presentar algunas de las primeras conclusiones de un análisis comparado de un grupo de biografías de estos viajeros. También se presentan los datos obtenidos del análisis de diferentes fuentes documentales poco conocidas y un esquema de periodificación de estos viajes.Scientific travel during late eighteenth century and early nineteenth century Spain has been regarded as an important issue concerning Spanish science. The large number of Spanish chemistry students who travelled to Paris during the Enlightenment seems to have played a mayor role in the transmission of chemical revolution. On the contrary, early nineteenth century scientific exile is usually considered as on of the major causes of the crisis of Spanish science during the nineteenth century. This paper aims to offer a general framework in order to study these group of scientific travellers and some conclusions of a comparative study of several of these biographies. Moreover, new data gathered in several Spanish and French archives is discussed and, as a result, a periodification is [email protected] [email protected]

Tourism and the SDGs: An Analysis of Economic Growth, Decent Employment, and Gender Equality in the European Union (2009-2018)

In 2015, the United Nations (UN) approved the 2030 Agenda on Sustainable Development to improve the lives of countries and societies. The World Tourism Organization (UNWTO) incorporated the agenda into the tourism industry. This study has as its primary objective an exploratory analysis of tourism activity in the EU-28 countries over the decade 2009-2018 and its adaptation to the Sustainable Development Goals through the lens of employment. This study focuses on the goals of decent employment and economic growth (O8) and gender equality (O5). The results obtained suggest that, in general, the eastern countries of the EU-28 show better values for Sustainable Development Goal (SDG) (8) and SDG (5) with respect to both employment and the wage gap. However, these countries have lower GDP-weighted remunerations, which can become an opportunity to obtain higher shares of tourism activity within the EU. It is concluded that there is a need to reinforce the awareness of the fabric of the tourism business and for public administrations to favor stable and decent employment and a reduction in the current gender wage gap

Pedro Gutiérrez Bueno (1745-1822), los libros de texto y los nuevos públicos de la química en el último tercio del siglo XVIII

El presente trabajo se enmarca en un proyecto de investigación acerca del papel de las prácticas y los conocimientos químicos en la transición de la materia médica a la farmacología experimental. Dentro de ese esquema general, el objeto de este artículo es el estudio de los libros de texto destinados a los estudiantes de medicina y de cirugía durante los años finales del siglo XVIII y la primera mitad del siglo XIX. En un estudio anterior, publicado en esta revista nos ocupamos de establecer las coordenadas institucionales generales dentro de las cuales fueron escritas, publicadas y leídas estas obras. Este trabajo es una continuación del anterior y está dedicado al análisis del «Curso de química» de Pedro Gutiérrez Bueno. A través de esta obra, se intenta ofrecer nuevos datos sobre los nuevos públicos de la química a finales del siglo XVIII y su influencia en la estructura y contenidos de los nuevos libros de texto

A Bibliometric Analysis of Sports Tourism and Sustainability (2002-2019)

Sports tourism is a relatively recent type of tourism, which has grown significantly in recent times. Not all effects of tourism are positive, so the analysis of its sustainability has particular relevance; especially since the publication of the 17 United Nations Sustainable Development Goals (SDGs) in 2015. The growing concern about tourism and sustainability makes it essential to examine how scientific research has adapted to new realities. This paper uses bibliometric techniques to investigate research trends related to sports tourism and sustainability. VOSviewer and SciMAT software were used. A total of 214 articles fromWeb of Science (WoS) indexed journals were analyzed. The results confirmed that interest in the study of these concepts has been growing, especially in the last four years. This is a comparatively new field of research (since 2002), so consolidated relations between thematic areas have yet to be observed, and there is a generally low concentration of authors and journals. Increases in several publications in this area are related to the celebration of mega sporting events or the publication of SDGs. The main contribution of this analysis lies in identifying important research issues, such as education and destination planning, which should continue to be addressed

Les Col·leccions universitàries d'instruments científics : el cas de la Universitat de València

This paper analyses the value of university collections of scientific instruments, their preservation, uses and improvement. It mostly relies on the data obtained by a research project on the scientific heritage of the University of Valencia

Estimation of specific cutting energy in an S235 alloy for multi-directional ultrasonic vibration-assisted machining using the Finite Element Method

The objective of this work is to analyze the influence of the vibration-assisted turning process on the machinability of S235 carbon steel. During the experiments using this vibrational machining process, the vibrational amplitude and frequency of the cutting tool were adjusted to drive the tool tip in an elliptical or linear motion in the feed direction. Furthermore, a finite element analysis was deployed to investigate the mechanical response for different vibration-assisted cutting conditions. The results show how the specific cutting energy and the material’s machinability behave when using different operational cutting parameters, such as vibration frequency and tool tip motion in the x-axis, y-axis, and elliptical (x-y plane) motion. Then, the specific cutting energy and material’s machinability are compared with a conventional turning process, which helps to validate the finite element method (FEM) for the vibration-assisted process. As a result of the operating parameters used, the vibration-assisted machining process leads to a machinability improvement of up to 18% in S235 carbon steel. In particular, higher vibration frequencies were shown to increase the material’s machinability due to the specific cutting energy decrease. Therefore, the finite element method can be used to predict the vibration-assisted cutting and the specific cutting energy, based on predefined cutting parameters.Peer ReviewedPostprint (published version