Species Boundaries and Population Divergence in the Pyrenean Endemic Relict Genus Borderea (Dioscoreaceae) as Revealed by Microsatellite (SSR) and Other Hypervariable Markers

Microsatellite alleles were used to delimit the genetic boundaries and divergence of the two relictual endemic Pyrenean taxa Borderea chouardii and B. pyrenaica (Dioscoreaceae), and to infer the different life histories followed by each species. Our study was conducted on the same populations previously analyzed with allozymes and RAPD markers. The three studied data sets were congruent in the inference of a single evolutionary scenario for the split of the two Borderea taxa from a common Tertiary ancestor in the Prepyrenees, thus supporting their taxonomic treatment as separate species. However, the more variable SSR and RAPD data provided better resolution for a stepping-stone model of local colonization of B. pyrenaica populations from southern Prepyrenean refugia to the northern Pyrenees. SSR markers proved to be more robust than RAPD markers in assessing the genetic structure of recently diverged populations of B. pyrenaica and thus qualified as the best molecular markers for fine-scale evolutionary investigations of Dioscoreaceae. Furthermore, microsatellites rendered unique clues to decipher the mechanisms involved in the origin of these relictual species and their genetic background. Borderea was shown to be a tetraploid genus of hybrid origin with a chromosome base number of x = 6. Phylogenetic data, karyological evidence, and our present knowledge based on microsatellite analyses allowed us to speculate that the Pyrenean endemic genus Borderea and its sister taxon, the Mediterranean genus Tamus, represent some of the oldest paleopolyploid lineages of the mostly pantropical yam family

¿Política-basura?: Modelos de representación y en la telebasura y la tertulia política

Si hay un formato informativo audiovisual que haya cobrado una vigencia y una relevancia inusitada como creador y modulador de la opinión pública, ése es sin duda la tertulia política televisiva, que ha encontrado su forma natural de desplegarse en el escenario de la TDT. El género ha ido a imbricarse en el vasto panorama de hibridaciones discursivas que proporciona la televisión actual influyendo y dejándose influir por formatos mucho más espectaculares en lo visual como el talk show y, en general, todas las variantes del reality. Esta comunicación realiza un estudio comparativo de los rasgos estructurales, discursivos y de puesta en escena que la tertulia política comparte con estos géneros denominados globalmente como telebasura y, de forma destacada, a los dedicados a la crónica rosa.If there is an audiovisual news format that has become an unusually powerful and up-to-date creator and modulator of the public opinion, then undoubtedly that must be the televised political chat show, which has found its natural means of deployment on the different TDT channels. The genre has gradually become interwoven within the vast panorama of discursive hybridisations offered by television today, while allowing itself to influence and be influenced by other formats that are visually far more spectacular, such as talk shows and in general all the different variants of reality shows. This communication conducts a comparative study of the structural, discursive and scenic features that a political chat show shares with these genres known around the world as trash TV and, more especially, those devoted to celebrity gossip

On the persistence of polar domains in ultrathin ferroelectric capacitors

The instability of ferroelectric ordering in ultra-thin films is one of the most important fundamental issues pertaining realization of a number of electronic devices with enhanced functionality, such as ferroelectric and multiferroic tunnel junctions or ferroelectric field effect transistors. In this paper, we investigate the polarization state of archetypal ultrathin (several nanometres) ferroelectric heterostructures: epitaxial single-crystalline BaTiO$_3$ films sandwiched between the most habitual perovskite electrodes, SrRuO$_3$, on top of the most used perovskite substrate, SrTiO$_3$. We use a combination of piezoresponse force microscopy, dielectric measurements and structural characterization to provide conclusive evidence for the ferroelectric nature of the relaxed polarization state in ultrathin BaTiO$_3$ capacitors. We show that even the high screening efficiency of SrRuO$_3$ electrodes is still insufficient to stabilize polarization in SrRuO$_3$/BaTiO$_3$/SrRuO$_3$ heterostructures at room temperature. We identify the key role of domain wall motion in determining the macroscopic electrical properties of ultrathin capacitors and discuss their dielectric response in the light of the recent interest in negative capacitance behaviour.Comment: 13 pages, 4 figure

Empresas y distritos industriales en el mercado mundial: una aproximación desde la historia económica

This paper deals with the contribution of industrial districts and clusters to the creation of competitive advantage in industry. It is divided into two well-differentiated parts. The first one provides an interpretative summary of key issues in the analysis of the geographic concentration of industry. In particular, some of the main interpretations and debates on the causes and characteristics of this concentration are presented. Additionally, it pays particular attention to the ongoing debate about the role of external economies (i.e. the externalities of industrial concentration) and internal economies (i.e. the strategies and capabilities of medium-large firms) in the competitiveness of districts and clusters. The second part of the paper reviews some recent studies, mostly focused on nineteenth- and twentieth-century Spain. This review, which includes historical analyses of districts, clusters and industries with export capacity, is undertaken in the light of the discussion in the first part of this study. An interesting conclusion that emerges from the studies reviewed is that in Southern Europe the competitive advantage of the geographically concentrated industry appears to have been associated more with hub-firm clusters than with neo-Marshallian districts (Main text in Spanish)industrial districts, clusters, competitive advantage, externalities, leading firms, economic history, industrial economics.

Essays in family economics and demographics: cultural/social norms, migration and gender stereotypes. International, national and regional (Aragón) evidence

El objetivo de esta tesis es proporcionar investigación en el campo de estudio de la economía familiar y la demografía. Las decisiones tomadas dentro del hogar pueden tener consecuencias importantes en varios campos de estudio económicos, como el mercado laboral. Motivada por estas implicaciones, esta tesis avanza en la comprensión de las decisiones tomadas por los individuos que están relacionadas con las normas sociales, locual es el hilo conductor a lo largo de la tesis. La tesis se divide en tres capítulos. En el Capítulo 1, que a su vez está dividido en tres trabajos empíricos, exploramos si las normas sociales pueden afectar a varias decisiones familiares y demográficas. Específicamente, examinamos el posible impacto de la cultura en: las decisiones de tener hijos de las mujeres, la elección de las parejas de vivir juntas (como pareja casada o no casada), asícomo las decisiones de tener una vivienda en propiedad. El Capítulo 2, que consta de dos trabajos empíricos, se centra en el comportamiento migratorio estudiando el efecto que sobre este pueden tener la cultura y la introducción de algunas leyes. El Capítulo 3 está dedicado al análisis de los estereotipos de género en los deportes y cómo los padres pueden influir las elecciones deportivas de sus hijos. Toda la evidencia empírica descritaen los diferentes capítulos apunta a la importancia de los roles sociales y de género en la determinación del comportamiento de los individuos.The aim of this thesis is to provide research in demographic and family economics. Intrahousehold decisions may have important consequences in several economic fields of study, such as the labor market. Motivated by these implications, this thesis advances in understanding of several individual choices related to social norms, which is the connecting thread throughout the thesis. This thesis is divided in three chapters. In Chapter 1, which consist of three empirical papers, we explore whether culture/social norms can have an effect on several family and demographic variables. Specifically, we examine the possible impact of culture on: women fertility decisions, couples¿ choice of living together (as a married or unmarried couple) as well as the home-ownership decisions. Chapter 2, which consist of two empirical papers, focuses on migration behavior studying the effect of culture and some legal factors. Chapter 3 is devoted to the analysis of gender stereotyping in sports and how parental investments shape boys and girls sport choices. All the empirical evidence described in the different chapters point to the importance of social and gender roles in determining the behavior of individuals.<br /

On the networked architecture of genotype spaces and its critical effects on molecular evolution

Evolutionary dynamics is often viewed as a subtle process of change accumulation that causes a divergence among organisms and their genomes. However, this interpretation is an inheritance of a gradualistic view that has been challenged at the macroevolutionary, ecological and molecular level. Actually, when the complex architecture of genotype spaces is taken into account, the evolutionary dynamics of molecular populations becomes intrinsically non-uniform, sharing deep qualitative and quantitative similarities with slowly driven physical systems: nonlinear responses analogous to critical transitions, sudden state changes or hysteresis, among others. Furthermore, the phenotypic plasticity inherent to genotypes transforms classical fitness landscapes into multiscapes where adaptation in response to an environmental change may be very fast. The quantitative nature of adaptive molecular processes is deeply dependent on a network-of-networks multilayered structure of the map from genotype to function that we begin to unveil.This work has been supported by the Spanish Ministerio de Economía y Competitividad and FEDER funds of the EU through grants ViralESS (FIS2014-57686-P) and VARIANCE (FIS2015-64349-P). J.A. is supported through grant no. SEV-2013-0347. P.C. is supported through the European Union's YEI funds

Bacterial viruses enable their host to acquire antibiotic resistance genes from neighbouring cells

Prophages are quiescent viruses located in the chromosomes of bacteria. In the human pathogen, Staphylococcus aureus, prophages are omnipresent and are believed to be responsible for the spread of some antibiotic resistance genes. Here we demonstrate that release of phages from a subpopulation of S. aureus cells enables the intact, prophage-containing population to acquire beneficial genes from competing, phage-susceptible strains present in the same environment. Phage infection kills competitor cells and bits of their DNA are occasionally captured in viral transducing particles. Return of such particles to the prophagecontaining population can drive the transfer of genes encoding potentially useful traits such as antibiotic resistance. This process, which can be viewed as ‘auto-transduction’, allows S. aureus to efficiently acquire antibiotic resistance both in vitro and in an in vivo virulence model (wax moth larvae) and enables it to proliferate under strong antibiotic selection pressure. Our results may help to explain the rapid exchange of antibiotic resistance genes observed in S. aureus

Pest risk analysis for Bactrocera invadens : Guidelines on Pest Risk Analysis

Stripping related moisture damage has been recognized as one of the major pavement distresses since the early 1990s. The main objective of this study is to establish an effective test protocol to quantify moisture susceptibility of asphalt pavements. To this end, selective test methods (Texas Boiling test, Tensile Strength Ratio, Retained Stability, and Hamburg Wheel Test), and procedures based on surface chemistries and molecular-level mechanistic properties have been investigated in this study. Firstly, a comprehensive list of literature related to moisture damage in asphalts was reviewed. Based on the literature review, a detailed project plan and test matrix were developed. Binder samples originated from two different crude sources were collected. The moisture resistance related tests such as static contact angle measurements and Texas Boiling tests were conducted. Besides, asphalt binders’ nanomechanical properties using an Atomic Force Microscopy (AFM) and surface chemistries using a static contact were evaluated in the laboratory. Based on limited test data and analysis, it is concluded that there does not exist any single test method that all agencies are comfortable and equipped to follow in their daily work as each technique has some merits and demerits. However, the Texas Boiling test is found to be the simplest method that requires minimal time and resources. On the other hand, surface chemistry and atomic force microscope-based techniques are becoming popular among researchers and pavement professionals. Findings of this study are expected to help ARDOT in selecting an appropriate moisture resistance test method that is simple, reliable, and easy to implement in their routine work

Tunable Molecular Electrodes for Bistable Polarization Screening

The polar discontinuity at any ferroelectric surface creates a depolarizing field that must be screened for the polarization to be stable. In capacitors, screening is done by the electrodes, while in bare ferroelectric surfaces it is typically accomplished by atmospheric adsorbates. Although chemisorbed species can have even better screening efficiency than conventional electrodes, they are subject to unpredictable environmental fluctuations and, moreover, dominant charged species favor one polarity over the opposite. This paper proposes a new screening concept, namely surface functionalization with resonance-hybrid molecules, which combines the predictability and bipolarity of conventional electrodes with the screening efficiency of adsorbates. Thin films of barium titanate (BaTiO) coated with resonant para-aminobenzoic acid (pABA) display increased coercivity for both signs of ferroelectric polarization irrespective of the molecular layer thickness, thanks to the ability of these molecules to swap between different electronic configurations and adapt their surface charge density to the screening needs of the ferroelectric underneath. Because electron delocalization is only in the vertical direction, unlike conventional metals, chemical electrodes allow writing localized domains of different polarity underneath the same electrode. In addition, hybrid capacitors composed of graphene/pABA/ferroelectric have been made with enhanced coercivity compared to pure graphene-electode capacitors

Enhanced performance controller for high power wind converters connected to weak grids

This study proposes a control scheme for high power grid-connected wind power converters, which is oriented to enhance their performance when connected to weak grids with low short circuit ratio. The proposed controller consists of an outer current reference generation loop and an inner current loop, working in stationary reference frame. In the outer loop, the current reference is calculated to comply simultaneously with the grid code requirements, the control of the DC link, and the operational safety margins of the converter during faulty conditions. On the other hand, the proposed inner current loop consists of a proportional resonant controller, a capacitor voltage feedforward and a phase shifter. Moreover, simulation results considering different weak grid conditions, as well as experimental results of a full-scale 4 MW converter test-bench are presented to validate the good performance of the proposed method.This work has been partially suported by the Spanish Ministry of Science and Universities under the code RTI2018-100921-B-C21 and Tecniospring programme under the code TECSPR16-1-006.Peer ReviewedPostprint (published version