954 research outputs found

    Enhancing organizational performance with social media use: the catalysing effect of corporate entrepreneurship

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    Social Media use has become pervasive and firms are increasingly relying on it, not only to relate to customers, but also to leverage internal processes like innovation. The strategic use of these tools can facilitate also the entrepreneurial orientation of the firm, as it provides useful knowledge which can make the firm more entrepreneurial, stimulating it to find new opportunities or innovative ideas where other companies do not recognize them. However, despite the relevance of the phenomenon in current hyper-competitive environments, empirical research on the topic remains scarce. To shed some light on the issue, the main purpose of the paper is to examine how Social Media use impacts the different dimensions of corporate entrepreneurship (new business venturing, innovativeness, proactiveness and self-renewal), enhancing also organizational performance. The study is intended to extend knowledge on this topic, by providing understanding of the path firms should take to benefit from Social Media use to become more entrepreneurial and achieve higher organizational performance, developing and nurturing competitive advantages. The paper analyses data obtained from a sample of 201 technological firms located in Spain. The methodology used is Structural equation modelling with LISREL analysis. Findings confirms how the use of Social Media tools positively impacted all the different dimensions of corporate entrepreneurship, translating also in enhanced performance. This paper contributes to the literature by empirically confirming in a structural model how Social Media use helps to create business value, by enhancing proactive behaviours, promoting strategic renewal inside the firm and increasing innovativeness and new business venturing and displaying the internal and sequential relationships among these dimensions.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Observational Δν\Delta\nu-ρˉ\bar\rho relation for δ\delta Sct stars using eclipsing binaries and space photometry

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    Delta Scuti (δ\delta Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations of eclipsing binaries with a δ\delta Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, we derived an observational scaling relation between the stellar mean density and a frequency pattern in the oscillation spectrum. This pattern is analogous to the solar-like large separation but in the low order regime. We also show that this relation is independent of the rotation rate. These findings open the possibility of accurately characterizing this type of pulsator and validate the frequency pattern as a new observable for δ\delta Sct stars.Comment: 11 pages, including 2 pages of appendix, 2 figures, 2 tables, accepted for publication in ApJ

    Monitoring the salt marsh vegetation and flora of the Baixo Vouga Lagunar (Ria of Aveiro, Portugal)

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    El carácter transicional de la Ría de Aveiro le confiere una riqueza florística singular, integrando comunidades vegetales típicas de las regiones Eurosiberiana y Mediterránea. La implantación del Proyecto Desenvolvimento Agrícola do Vouga (PDAV) va a provocar una modificación de las tasas de encharcamiento y una reducción gradual de la salinidad, factores ecológicos determinantes para muchas de las comunidades halófilas y helofíticas. El presente trabajo pretende contribuir a un mejor conocimiento de la tipología de la vegetación local, que sirva como base para desarrollar un programa de monitorización adecuado que detecte las alteraciones en los patrones espacio- temporales de la vegetación de los sistemas húmedos. Teniendo como objetivo seleccionar los puntos de muestreo donde instalar las parcelas permanentes de monitorización, se realizó una caracterización de la flora y la vegetación a través de trece transectos utilizando una aproximación simplificada al método de Braun- Blanquet. Una vez identificados los tipos de vegetación - en función de su composición florística, corología y ecología - fueron seleccionados al azar inventarios representativos de cada tipo, en los que han sido instaladas dichas parcelas.The transitional biogeographic character of the Ria de Aveiro lagoon area confers it a singular floristic richness, integrating plant communities typical for the Eurosiberian as well as Mediterranean Region. The implementation of the Agricultural Development Plan of the Lower Vouga area (PDAV) in the near future is expected to result in noticeable changes in the tidal submersion regime and a gradual reduction of salinity levels, which are determining ecological factors for many of the halophytic and helophytic plant communities. The present work pretends to contribute to a better knowledge of the local vegetation types and, thereby, to the implementation of an adequate monitoring programme for detecting changes in the spatio-temporal vegetation patterns of the wetlands. With the objective to select the locations for the installation of permanent quadrats, the vegetation of the wetlands was described along 13 transects using a simplified Braun-Blanquet approach. A total of 24 local vegetation types were recognised, 23 of which were selected for the current monitoring programme

    Vibrational and thermal studies of essential oils derived from Cistus ladanifer and Erica arborea shrubs

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    Essential oils from the two most representative shrub species from the Iberian Peninsula (namely Cistus ladanifer L. and Erica arborea L.) have been characterized by Fourier transform infrared spectroscopy (FTIR) and thermoanalytical techniques (TG/DTG and DSC). Vibrational spectra have been compared with those of components of the plants, and with those of oils, gums and resins from other species. The different content in terpenoids of C. ladanifer oil (mainly mono-and sesquiterpenoids) and E. arborea oil (mainly triterpenoids) is reflected in the ATR-FTIR by the position of the bands at around 2873 cm-1, 1730 cm-1 and 1678 cm-1. As regards their thermal behavior, C. ladanifer-derived oil evinced higher thermal stability than that of obtained from E. arborea: The pyrolysis of the former was sensitized at 210°C, whereas for the later it occurred at 143°C. These temperatures are high enough to state that thermolabile constituents such as terpenoids are conserved in the hydrodistillation and that this extraction process ensures the recovery of the main constituents of both essential oils

    Young nearby open clusters and their luminosity functions

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    Context. Open clusters are groups of coeval stars sharing properties such as distance and metallicity, and they are key to understanding stellar evolution. Aims. Our main goal is to study the evolution of open clusters with a special focus on the universality of the luminosity function. Methods. We applied an upgraded version of the convergent point technique on about 50 open clusters. The selection of cluster members was based purely on the exquisite astrometry of the Gaia DR3 and Hipparcos catalogues in the five-dimensional or full six-dimensional space. Results. We present updated lists of bona fide members of ~50 open clusters within 500 pc and younger than 1 Gyr, exploiting the full depth of the third Gaia data release complemented by Hipparcos at the bright end, excluding regions in the Galactic plane. Our catalogues also are complemented by optical and infrared photometry from the major large-scale public surveys. All the data will be made available on a dedicated webpage with interactive plots and a direct link to Aladin and Vizier hosted at the Centre de Donn\'ees de Strasbourg. We derived luminosity functions for all bound clusters and compared them in three age groups of ~50 Myr, ~150 Myr, and ~600 Myr, discussing similarities and differences to constrain their dynamical evolution. Conclusions. Luminosity functions of clusters at 50 Myr are more likely similar to each other and show a greater degree of similarity than older clusters. We explain this observation with the universal luminosity function within the volume of our sample (500 pc). Luminosity functions of clusters with ages similar to the Pleiades or Hyades are more diverse, perhaps due to internal dynamical evolution, but more work is needed to provide additional evidence.Comment: 29 pages, 9 figures, accepted for publication in Astronomy & Astrophysic

    Fixation of bioactive compounds to the cuticle of Artemia

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    Artemia is extensively used in aquaculture to feed early stages of cultured marine species. A problem associated with this practice is that Artemia fails to supply some essential nutrients. As a possible solution, we have devised a procedure to make Artemia a vehicle for exogenous nutrients and other bioactive compounds. It consists of the construction of chimeric proteins composed of a chitin-binding domain, which binds to the cuticle of Artemia, and a carrier domain that conveys a functional property. As confirmatory examples, we describe the successful fixation to Artemia's metanauplii of two hybrid proteins: a β-galactosidase from the thermophilic bacterium Thermotoga maritima and the jellyfish green fluorescent protein (GFP), both linked to the CBM2 chitin-binding domain from the hyperthermophilic archaeon Pyrococcus furiosus. Positive results of experiments carried out ex vivo and in vivo show the validity of this approach. The methodology used could become a general procedure for the attachment of different kinds of bioactive compounds, such as enzymes, hormones, antibiotics, etc., to the cuticle of Artemia as well as other arthropods. Statement of relevance: Our results overcome shortcomings of Artemia as a feedstock.En prensa2,04

    Mediterranean shrublands as carbon sinks for climate change mitigation: new root-to-shoot ratios

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    Shrublands play an important role in the reduction of atmospheric CO2 and contribute to the mitigation of the effects of climate change, due to their ability to act as carbon sinks and the large expanses of land involved. Two of the most representative shrub species in the Iberian Peninsula, Cistus ladanifer L. and Erica arborea L., were studied in terms of biomass distribution and carbon and nitrogen contents in the different fractions. With a view to fast and cost-effective estimation of radical biomass, a new procedure for easy root-to-shoot calculation based on vibrational data was proposed, resulting in an excellent agreement with the values obtained from conventional direct belowground and aerial biomass measurements: 0.23 for C. ladanifer and 0.54 for E. arborea. Carbon sequestration, estimated at 45 and 73 t CO2 eq·ha-1 for C. ladanifer and E. arborea, respectively, was subsequently determined. Since these values are substantially higher than those of other shrubs, these two key species can be deemed particularly promising for ecological restoration and carbon offsetting
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