Electric-magnetic duality in linearized Ho\v{r}ava-Lifshitz gravity

Known as a symmetry of vacuum Maxwell equations, the electric-magnetic duality can be lifted actually to a symmetry of an action. The Lagrangian of this action is written in terms of two vector potentials, one electric and one magnetic, and while it is manifestly invariant under duality rotations, it is not manifestly Lorentz covariant. This duality symmetry exists also in linearized gravity in four dimensions, and can be lifted off shell too. In $d$ dimensions, the link between linearized gravity and its dual can also be seen from the point of view of a parental action. This is defined by a first order Lagrangian (with the help of some auxiliary variables) that delivers both Fierz-Pauli theory and its dual. In this work we use this formalism to implement the electric-magnetic duality in the nonrelativistic deviation of Fierz-Pauli theory arising from Ho\v{r}ava-Lifshitz gravity. Because this theory breaks diffeomorphism invariance, one finds that such implementation includes some peculiarities.Comment: v1: 23 pages, 4 figures, edited with LaTeXila 2.4.0 and wxMaxima 12.04.0 for the graphics (Maxima version: 5.27.0). arXiv admin note: text overlap with arXiv:1306.1092 by other authors; v2: 24 pages, 4 figures, references added, negligence (leading to poor version management and miscommunication) rectified; v3: typos and grammar corrected, minor changes to uniformize convention

Factors affecting innovation revisited

El 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 construidos.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 taxonomy.Innovation, Factors affecting innovation, Multinational enterprises, Sectoral taxonomies, Spain.

Space, mass and ornament in the Gothic-Renaissance transition in Spain

La introducción en España de las nuevas formas y sintaxis renacentistas a lo largo del siglo xvi no se produjo con un abandono radical e inmediato de los viejos usos góticos, de validez comprobada en trascendentales cuestiones del diseño arquitectónico. La renovación de la producción fue heterogénea y en cierto modo particular de cada artífice, según su formación previa y el grado de contacto, coherencia y compromiso con las novedades italianas, generando un panorama híbrido y plural en la arquitectura del quinientos hispano. Atendiendo a significativos textos y documentos gráficos de la época, se pretende rastrear los cambios, e inercias, en el proceso de diseño arquitectónico durante esta larga etapa de transición, estructurando el análisis a partir de tres categorías sustanciales, interdependientes y autónomas a la vez: espacio, masa y ornato.During the sixteenth century the new Renaissance forms were introduced in Spain, but the Gothic procedures continued to be used due to their proven validity for the architectural design. The renovation of the architecture was heterogeneous and different for each master, according to his previous training and his knowledge of the new Italian forms. This involved a hybrid and plural context in the Spanish architecture of the 16th century. The changes and continuities of the architectural design process during this transitory stage are investigated in this paper, based on significant texts and graphic documents of this period. The analysis is structured based on three substantial architectural categories, which are simultaneously interdependent and autonomous: space, mass and ornamen

Rapid asymmetric transfer hydroformylation (ATHF) of disubstituted alkenes using paraformaldehyde as a syngas surrogate

The authors thank Dr. Reddys (UK) and the Royal Society for an Industry Fellowship in the early stage of this work (2012–2014), and the EPSRC for funding (EP/M003868/1).As an alternative to conventional asymmetric hydroformylation (AHF), Asymmetric Transfer Hydroformylation (ATHF) using formaldehyde as a surrogate for syngas is reported. A catalyst derived from commercially available [Rh(acac)(CO)2] and Ph-BPE stands out in terms of both activity and enantioselectivity. Remarkably, not only are high selectivities achievable, the reactions are very simple to carry out, and can give higher enantioselectivity (up to 96% e.e.) and/or turnover frequencies than those that are achievable using the same catalyst (or other leading catalysts) using typical conditions for AHF.Publisher PDFPeer reviewe

Publishing performance in economics: Spanish rankings (1990-1999)

This paper contributes to the growing literature that analyses the Spanish publishing performance in Economics throughout the 1990s. Several bibliometric indicators are used in order to provide Spanish rankings (of both institutions and individual authors) based on Econlit journals. Further, lists of the ten most influential authors and articles over that period, in terms of citations, are reported.Publicad

Effect of elevated inorganic carbon on the cytosolic homeostasis of NO3- in the marine angiosperm Posidonia oceanica (L.) Delile

The marine angiosperm Posidonia oceanica is a mediterranean endemism of great ecological significance. As other marine plants, P. oceanica has adapted secondarily to the marine environment and develop anew different mechanisms to colonize it. Among others, this plant has developed a plasma membrane system for the direct uptake of bicarbonate. In this work we have developed both NO3- and Cl- selective microelectrodes for the continuous monitoring of the intracellular (cytosolic) NO3- and Cl-. In the light, leaf mesophyll cells show a cytosolic NO3- concentration of 5.7±0.2 mM (n=10), while in the dark cytosolic NO3- raises up to 8.7±1.1 mM; these values are in the range of concentrations quoted for Arabidopsis thaliana (Cookson et al., 2005). The enrichment of natural seawater (NSW) with 3 mM NaHCO3 caused a decrease of the cytosolic NO3- concentration of 1 mM and a decrease of the cytosolic concentration of Cl- of 3.5 mM. The saturation of NSW with 1000 µL CO2 L-1 produced a lower diminution of the cytosolic NO3- (0.3 mM). In the presence of 0.1 mM of the plasma membrane permeable inhibitor of the carbonic anhydrase (EZ) the diminution of cytosolic NO3- caused by the same concentration of CO2 was much lower, 0.1 mM. The addition of inorganic carbon, either HCO3- or CO2, has an effect on the cytosolic mechanisms for anionic homeostasis, one of which is the opening of the slow anion channels. These channels are permeable to NO3- and Cl- and could elicit the efflux of these ions. In P. oceanica, the response in the presence of EZ points out that the inorganic carbon species that cause the NO3-/Cl- efflux is HCO3-. This effect could contribute to plant biomass N dilution observed in elevated CO2. References: Cookson et al. 2005. Plant Physiology 138, 1097–1105.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

HCO3- enrichment causes cytosolic NO3- efflux in Posidonia oceanica leaf cells

Posidonia oceanica is a seagrass, the only group of vascular plants to colonize the marine environment. Seawater is an extreme yet stable environment, characterized by high salinity, alkaline pH and low availability of essential nutrients, such as nitrate or phosphate. In addition, in aquatic environments the supply of CO2 for the photosynthesis is limited by diffusion and therefore many aquatic plants use HCO3- as the inorganic carbon source for photosynthesis. Previous results have shown that Na+ -dependent transport systems operate on the plasma membrane of P. oceanica mesophyll leaf cells for the high-affinity NO3-, Pi or amino acids uptake. Also, a direct transport of HCO3- driven by H+ has been found in this species that provides inorganic carbon for photosynthesis and could be a significant component of a carbon concentrating mechanism in this species. Interestingly, this HCO3- direct uptake caused the efflux of chloride from the cytosol, probably through S-type anion channels, pointing that other anions could also be removed from the cytosol. This hypothesis could be relevant in the case of NO3-, since the decrease of cytosolic NO3- in response to HCO3- enrichment could limit N-assimilation. Here we analyse the effect of HCO3- increase on NO3- uptake and cytosolic homeostasis in P. oceanica. Enrichment of natural seawater with 3 mM HCO3- evokes the on-going decrease of cytosolic NO3-, from 5.7 ± 0.2 to 4.8 ± 0.7 mM after 40 min of treatment. The incubation of P. oceanica leaf pieces in 3 mM HCO3- NSW causes an initial increase of NO3- concentration in the medium. Maximum efflux (21 nmol NO3- gFM-1 min-1) occurs within the first minute of incubation. Then, external NO3- is depleted from the medium at lower net uptake rate than the value observed in non HCO3- -enriched natural seawater. These results fit the hypothesis that HCO3- enrichment causes the nitrogen loose and could impair nitrogen assimilation promoting N biomass impoverishment.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Spanish MINECO, projects BFU2017-85117-R and BIO2016-81957-RED

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

Response to Boric Acid and Light in the Number and Biomass of Potato Microtubers Cv. “Floresta”

Con el propósito de conocer la respuesta en el número y la biomasa de microtubérculos de papa (Solanum tuberosum L. “Floresta”), se evaluó, bajo condiciones de cultivo in vitro, el efecto de cuatro concentraciones de ácido bórico: 6.2 mg l-1, 7.75 mg l-1, 9.3 mg l-1 y 10.85 mg l-1 en dos condiciones: oscuridad y fotoperiodo de 16 horas luz y 8 horas de oscuridad. El medio que se utilizó como testigo fue Murashige y Skoog. El análisis de los datos para el número y la biomasa de microtubérculos fue significativo para la condición de oscuridad (p≤0,05). En relación con la concentración de ácido bórico y la interacción entre los factores, se obtuvieron diferencias significativas para la biomasa (p≤0,05). De manera que, en la condición de oscuridad, se obtuvo un mayor número de microtubérculos; sin embargo, su biomasa fue menor. Para la condición con iluminación, la biomasa fue mayor y el número de microtubérculos fue menor con respecto a la condición con oscuridad. La concentración de 9,3 mg l-1 de ácido bórico en ambas condiciones fue el mejor tratamiento para producir un mayor número y biomasa de microtubérculos. Las diferencias indicadas en este trabajo en relación con el número y la biomasa de microtubérculos probablemente son el resultado conjunto del genotipo y las condiciones específicas de cultivo. Aun así, se propone la utilización de una condición de iluminación para inducir microtubérculos más grandes y verdes.In order to understand the performance of Solanum tuberosum L. “Floresta” in producing microtubers, the effect of four concentrations of boric acid (6.2 mg l-1, 7.75 mg l-1, 9.3 mg l-1, and 10.85 mg l-1) under two conditions—1) 8 hour dark and 2) 16 hour light photoperiod and 8 hour dark—was evaluated under in vitro culture conditions. Full-strength Murashige and Skoog medium was used as a control. The data analysis for the number and biomass of microtubers were significant for the condition (p ≤ 0.05). Concerning the concentration of boric acid and the interaction between factors, a significant difference was obtained for biomass (p ≤ 0.05). In dark conditions, a greater number of microtubers was obtained, although the biomass was lower compared to the light conditions where the biomass was higher, and the number of microtubers was lower. A concentration of 9.3 mg l-1 of boric acid in both types of conditions was the best treatment to produce a greater number and more biomass of microtubers. The differences identified in this work with regards to the number and biomass of microtubers were probably the combined result of genotype and specific culture conditions. Even considering this, the use of lighting conditions is proposed to induce larger and greener microtubers

The science of the principles and the first causes in the first book of the Metaphysics

En este trabajo se presenta la concepción aristotélica de la filosofía primera como ciencia de los principios y de las causas primeras según el libro primero de la Metafísica. Para ello, se distinguen tres momentos sucesivos que constituyen el análisis de la naturaleza y la meta que debe alcanzar esta ciencia: 1) la concepción de la sabiduría como ciencia que se ocupa de ciertos principios y causas; 2) la sabiduría como ciencia de los primeros principios y de las causas; 3) la determinación de las cuatro causas primeras como tarea de la filosofía primera. De este modo, se pretende mostrar que la Metafísica de Aristóteles es un intento para explicar las últimas cuestiones, el último porqué, indicando cuatro géneros diferentes de respuesta.This paper pretends to show the aristotelian conception of the first philosophy as the science of the principles and the first causes according to the first book of the Metaphysics. In order to do this, three successive moments are distinguished which constitute the analysis of the nature and the goal that this science must attained: 1) the conception of wisdom as a science that deals with certain principles and causes; 2) wisdom as a science of first principles and causes; 3) the determination of the four first causes as a task of the first philosophy. In this way, the aim of this work is to show that the Metaphysics of Aristotle is an attempt to explain the ultimate questions, the ultimate why, indicating four different genera of answer