429 research outputs found

    Ownership and Control: A Spanish Survey

    Get PDF
    The paper analyses the ownership structure of a large sample of Spanish listed companies. The results are analysed in terms of governance implications under the agency theory context. The results show a picture with concentrated ownership where stock markets are relatively low important. Direct ownership and voting blocks, which account for indirect ownership through third companies, are larger for non-financial firms followed by families or individuals and financial firms other than banks. Nevertheless, the use of intermediate companies (pyramiding), is not frequent according to our data. Banks seem not to play the important role they did in the past and the recent privatisation reduced to a minimum level, state shareholdings on listed companies.Ownership, Control, Spain

    Scalar and vector meson exchange in V->P0P0gamma decays

    Full text link
    The scalar contributions to the radiative decays of light vector mesons into a pair of neutral pseudoscalars, VP0P0γV\to P^0P^0\gamma, are studied within the framework of the Linear Sigma Model. This model has the advantage of incorporating not only the scalar resonances in an explicit way but also the constraints required by chiral symmetry. The experimental data on ϕπ0π0γ\phi\to\pi^0\pi^0\gamma, ϕπ0ηγ\phi\to\pi^0\eta\gamma, ρπ0π0γ\rho\to\pi^0\pi^0\gamma and ωπ0π0γ\omega\to\pi^0\pi^0\gamma are satisfactorily accommodated in our framework. Theoretical predictions for ϕK0Kˉ0γ\phi\to K^0\bar K^0\gamma, ρπ0ηγ\rho\to\pi^0\eta\gamma, ωπ0ηγ\omega\to\pi^0\eta\gamma and the ratio ϕf0γ/a0γ\phi\to f_0\gamma/a_0\gamma are also given.Comment: 42 pages, 11 figures. A new paragraph explaining the seminal contribution of Ref. [19] is adde

    On the gluon content of the eta and eta' mesons

    Full text link
    A phenomenological analysis of radiative VPγV\to P\gamma and PVγP\to V\gamma decays is performed with the purpose of determining the gluonic content of the η\eta and η\eta^\prime wave functions. Our results show that within our model there is no evidence for a gluonium contribution in the η\eta, Zη2=0.00±0.12Z_\eta^2=0.00\pm 0.12, or the η\eta^\prime, Zη2=0.04±0.09Z_{\eta^\prime}^2=0.04\pm 0.09. In terms of a mixing angle description this corresponds to ϕP=(41.4±1.3)\phi_P=(41.4\pm 1.3)^\circ and ϕηG=(12±13)|\phi_{\eta^\prime G}|=(12\pm 13)^\circ. In addition, the η\eta-η\eta^\prime mixing angle is found to be ϕP=(41.5±1.2)\phi_P=(41.5\pm 1.2)^\circ if we don't allow for a gluonium component.Comment: 16 pages, 3 figures, JHEP style. First part of data fitting changed, conclusions not modifie

    Effects of pulsed discharges from a hydropower station on summer diel feeding activity and diet of brown trout (Salmo trutta Linnaeus, 1758) in an Iberian stream.

    Get PDF
    The influence of pulsed discharges associated with hydroelectric power generation (i.e. hydropeaking) on feeding activity and diet composition of adult brown trout (Salmo trutta) was studied during the summer by comparing two sites: upstream (control site) and downstream from a power plant (hydropeaking site). Twenty fish were captured from each study site by electrofishing at 4-hour intervals for two consecutive days and stomach contents were collected with pulsed gastric lavage. Hydropeaking events affected brown trout feeding behaviour as well as prey availability. Feeding intensity, measured by the stomach Fullness Index, showed pronounced variations with maximum values after flow pulses, which were linked to variations in prey availability because of increased drift rates of invertebrates. In contrast, brown trout living at the control site showed smoother variations in feeding activity not linked to invertebrate drift. Overall, brown trout at the hydropeaking site had higher food consumption rates and a more generalist and heterogeneous diet than trout from the control site, indicating an opportunistic feeding behaviour during flow pulses. Therefore, the hydrological disturbance caused by hydropeaking did not appear to cause direct negative impacts on feeding of adult brown trout. However, reduced trout density and imbalanced size structure in the hydropeaking site were detected, requiring further research to clarify the spatial influence of hydropeaking on other factors that could negatively affect brown trout populations

    Commercial and industrial implication of the variability of oil and protein content and of the nut and kernel physical traits of almond in Mediterranean climates

    Get PDF
    Se determinaron los caracteres físicos y la composición química de los frutos de 11 cultivares de almendro cultivados en dos zonas distintas, Zaragoza (España) y Meknès (Marruecos). Independientemente de la variabilidad entre cultivares para todos los parámetros medidos, el efecto del año fue significativo para todos los parámetros físicos, excepto para el espesor de la pepita. Igualmente fue significativo el efecto de la localidad para todos los parámetros físicos, excepto para la longitud y el índice de esfericidad del fruto, la longitud y la anchura de la pepita, y el rendimiento en pepita. La calidad física de las pepitas producidas en Zaragoza fue mayor que las producidas en Meknès, probablemente por el diferente sistema de cultivo y las condiciones ambientales que fueron más extremas en Meknès. Estos resultados muestran que las condiciones de cultivo adecuadas favorecen el aumento de los caracteres conducentes a una mayor calidad física del fruto y de la pepita. En cuanto al contenido en aceite y en proteína, se encontraron diferencias significativas entre los genotipos y las localidades. Las condiciones ambientales y de cultivo de Zaragoza favorecieron la acumulación de aceite en la pepita, mientras que las de Meknès favorecieron la acumulación de proteína. Ello apunta a que la utilización industrial de los distintos cultivares estudiados no sólo depende del propio cultivar, sino también de las condiciones ambientales y de cultivo, lo que debe tenerse muy en cuenta para la valorización de la producción en las distintas zonas de cultivo del almendroThe fruit physical traits and the chemical composition were determined for 11 almond cultivars grown in two different regions: Zaragoza (Spain) and Meknès (Morocco). Independently of the variability among cultivars for all traits measured, the year effect was significant for all physical traits except for kernel thickness. The location effect was significant for all physical traits except for fruit length and sphericity, kernel length and width, and kernel percentage. The physical quality of the kernels produced in Zaragoza was higher than that of the kernels produced in Meknès, probably because of the different growing system and the environmental conditions, more extreme in Meknès. These results show that adequate growing conditions favour the increase of traits leading to increased physical quality of nuts and kernels. The cultivar and the location effects were significant for the contents of oil and protein. The environmental and growing conditions of Zaragoza led to a higher oil accumulation, whereas those of Meknès to a higher protein accumulation. These results indicate that the industrial utilization of the different almond cultivars does not only depend on the cultivar, but also on the environmental and growing conditions, a fact to be considered when marketing the production of the different growing region

    Flowering and pollination time affect fruit set of foreign almond cultivars in Morocco

    Get PDF
    The associations ‘Marcona’-‘Fournat de Brézenaud’ and ‘Ferragnès’-‘Ferraduel’ are the cultivar combinations mostly planted in commercial almond orchards in Morocco. The blooming times and effective pollination period (EPP) were determined for these associations to determine the effect of blooming and pollination times on the irregular yields observed in Morocco with these cultivars. ‘Marcona’ bloom was earlier than that of ‘Fournat de Brézenaud’, but ‘Ferragnès and ‘Ferraduel’ coincided. Fruit set and percentage of pistils with pollen grains was maximized when pollination occurred at day 2 after emasculation. Fruit set and stigmatic receptivity decreased drastically by day 4 after emasculation. Fruit set in the open pollination treatment was lower than that obtained after hand pollination at days 0 and 2 after emasculation, especially in ‘Marcona’. These results emphasize the importance of early pollination and the selection of new cultivars with the same flowering period as ‘Marcona’ to improve almond yields in Morocco.Peer ReviewedPrunus amygdalusbloomeffective pollination periodstigmatic receptivityfruit setPublishe

    Phytosterol variability in almond germplasm

    Get PDF
    Phytosterols are important dietary components that contribute to reducing serum cholesterol levels. The objective of this research was to assess genetic diversity for total content and profile of free and esterified phytosterols in a world germplasm collection of almond [Prunus amygdalus Batsch; syn. P. dulcis (Mill.) D.A. Webb]. Steryl glycosides and acylated steryl glycosides were not measured. Fruit from 160 almond accessions were collected in 2009 and 2010. Kernel phytosterol content ranged from 1126 to 2769 mgkgL1 in 2009 and from 1191 to 2777 mgkgL1 in 2010. The phytosterol fraction was mainly made up of b-sitosterol (from 59.1% to 84.1% in 2009 and from 55.9% to 84.6% in 2010) and D5 -avenasterol (from 8.9% to 25.4% in 2009 and from 8.5% to 28.2% in 2010). Significant genotypic effects were observed for kernel phytosterol content and concentration of major phytosterols. Kernel oil content was positively correlated with kernel phytosterol content in both years. The results suggested that almond germplasm contains genetic variability for both phytosterol content and profile that can be used for developing cultivars with increased levels of phytosterols and contrasting phytosterol profiles. Positive correlation between kernel phytosterol content and kernel oil content suggests the feasibility of simultaneous selection for both traits.Publishe

    Study of the genetic diversity of almond seedling populations in Morocco: application of chemometric approach

    Get PDF
    Almond (Prunus amygdalus Batsch) in Morocco is still propagated by farmers mostly from seed, generating a large genetic diversity. Evaluation of the almond diversity in Morocco from the point of view of kernel quality, oil and protein contents, and major fatty acid composition were determined. Principal component analysis (PCA) was used to compare the kernel components among 46 genotypes selected from different production regions, as well as five introduced cultivars. Oil and protein contents were highly variable between genotypes, ranging respectively from 48.29 to 65.19% and from 14.07 to 36.48% of the total kernel dry weight. Fatty acid composition of the oil fraction ranged between 5.6-8.34% for palmitic acid, 0.37-0.87% for palmitoleic acid, 1.3-3.3% for stearic acid, 57.95-81.97% for oleic acid, and 9.69-29.98% for linoleic acid. Clustering of genotypes from similar regions suggested the existence of parental relationship among these genotypes and, as a consequence, a common ancestral origin. The Moroccan genotypes did not cluster separately from the introduced varieties. Two genotypes had very high oil contents whereas four genotypes had exceptionally high protein contents (>30%). One genotype had a very high oleic content (82%). The large variability observed for oil and fatty acid composition and the presence of genotypes with higher oil and fatty acid contents than the foreign cultivars represent a very promising base to obtain new Moroccan almond cultivars with oil of higher quality.Peer ReviewedPrunus amygdalusOil contentFatty acidsGenetic resourcesBreedingPublishe
    corecore