1,084 research outputs found

    Boards of directors: composition and effects on the performance of the firm

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    This paper analyses the structure of boards of directors and its impact on business performance, which is approximated by economic profitability and the Tobin’s Q ratio. We focus on three basic aspects of boards that have been reviewed in the recent reform of the Good Governance Code: the size of boards, their independence and their diversity. For the study of diversity, we use an index that integrates not only the gender of board members, but also their age and nationality, since these are factors that can influence the knowledge, experience and skills of the directors. The results confirm a high degree of compliance with the recommendations of the Good Governance Code, and suggest that the performance of the advisory and monitoring functions are factors that determine the composition of boards. With respect to the performance of the company, we note that there is a negative and significant relationship with the independence of boards. However, the results are sensitive to the performance measure employed

    Effect Of Nb And Cu On The Crystallization Behavior Of Understoichiometric Nd–Fe–B Alloys

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    In this work, we present a complete study of the influence of Nb and Cu addition on the crystallization behavior of Nd-lean Nd-Fe-B melt-spun alloys. Alloys with compositions Nd10-x-yFe84B6NbxCuy (x = 1, y = 0 and x = 0.5, y = 0.5) were melt-spun at different wheel speeds (15-40 m s(-1)) to obtain samples in amorphous, highly disordered and nanocrystalline structures. The crystallization process, induced by different heat treatments, was studied by means of differential thermal analysis and x-ray powder thermodiffraction. Magnetic properties of as-made and heat-treated ribbons were measured by magnetometry. The as-made amorphous samples showed a crystallization to the 2: 14: 1 hard magnetic phase at T-1 similar to 350 degrees C. Doping with Nb results in an increase of T1, and addition of Cu lowers T1. This behavior is explained in terms of an inhibition of grain growth by Nb and a nucleation enhancement by Cu additions. During the crystallization process, a secondary phase (identified as a bcc-Fe-rich phase) is formed. The amount of such a phase increases with the annealing temperature. Coercivity increases upon annealing reaching maxima at 700-750 degrees C. This can be explained in terms of competition between the two phases formed: the 2: 14: 1 hard phase and the soft bcc-Fe-rich phase. The highest coercivity of the Nd-lean samples is observed when the microstructure is appropriate and both phases are exchange-coupled.This work has received funding from the DOE BES-DE-FG02-90ER45413 and the European Union MSCA grant agreement No 691235 (INAPEM). Technical and human support provided by SGIker (UPV/EHU, GV/EJ and ESF) is gratefully acknowledged

    Recensiones [Revista de Historia Económica Año XI Invierno 1993 n. 1 pp. 209-243]

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    Editada en la Universidad Carlos IIILutgardo García Fuentes. Sevilla, los vascos y América. (Las exportaciones de hierro, manufacturas metálicas en los siglos XVI, XVII y XVIII) (Por Rafael Uñarte Ayo).-- Enrique Tandeter. Coacción y mercado. La minería de la plata en el Potosí Colonial 1692-1826 (Por Zacarías Moutoukias).-- Manuel Miño Grijalva. Obrajes y tejedores en Hueva España (1700-1810) (Por Pedro Pérez Herrero).-- Luis Perdices Blas.Pablo de Olavide (1725-1803), el Ilustrado (Por Victoriano Martin Martín).-- Daniel Peribáñez Caveda. Comunicaciones y comercio marítimo en la Asturias preindustrial (1750-1850) (Por José Ramón García López).-- Vicent Llombart.Campomanes, economista y político de Carlos III (Por Luis Perdices Blas).-- M. Teresa Pérez Picazo.El mayorazgo en la historia económica de la región murciana, expansión, crisis y abolición (siglos XVIII-XIX) (Por Juan Antonio Carmona Pidal).-- Nelson Lourenço. Familia rural e industria. Mudanga social na regido de Leiria (Por Carmen Sarasúa García).-- Blanca Sánchez Alonso.La inmigración española en Argentina, siglos XIX y XX (Por José Moya).-- Gianni Toniolo.An Economic History qf Liberal Italy, 1859-1918 (Por Francesco L. Galassi).-- Albert Carreras. Estadísticas históricas de España. Siglos XIX-XX (Por Sebastian Coll Martín)Publicad

    Existence of naked singularities in Brans-Dicke theory of gravitation. An analytical and numerical study

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    Within the framework of the scalar-tensor models of gravitation and by relying on analytical and numerical techniques, we establish the existence of a class of spherically symmetric spacetimes containing a naked singularity. Our result relies on and extends a work by Christodoulou on the existence of naked singularities for the Einstein-scalar field equations. We establish that a key parameter in Christodoulou's construction couples to the Brans-Dicke field and becomes a dynamical variable, which enlarges and modifies the phase space of solutions. We recover analytically many properties first identified by Christodoulou, in particular the loss of regularity (especially at the center), and then investigate numerically the properties of these spacetimes.Comment: 26 pages, PACS numbers: 04.20.Dw, 04.25.dc, 04.50.K

    Resonant radiation pressure on neutral particles in a waveguide

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    A theoretical analysis of electromagnetic forces on neutral particles in an hollow waveguide is presented. We show that the effective scattering cross section of a very small (Rayleigh) particle can be strongly modified inside a waveguide. The coupling of the scattered dipolar field with the waveguide modes induce a resonant enhanced backscattering state of the scatterer-guide system close to the onset of new modes. The particle effective cross section can then be as large as the wavelength even far from any transition resonance. As we will show, a small particle can be strongly accelerated along the guide axis while being highly confined in a narrow zone of the cross section of the guide.Comment: RevTeX,4 pages,3 PS figure

    Effectiveness of sacubitril–valsartan in cancer patients with heart failure

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    Aims Current guidelines recommend sacubitril/valsartan for patients with heart failure and reduced left ventricular ejection fraction (LVEF), but there is lack of evidence of its efficacy and safety in cancer therapy-related cardiac dysfunction (CTRCD). Our aim was to analyse the potential benefit of sacubitril/valsartan in patients with CTRCD. Methods and results We performed a retrospective multicentre registry (HF-COH) in six Spanish hospitals with cardiooncology clinics including all patients treated with sacubitril/valsartan. Demographic and clinical characteristics and laboratory and echocardiographic data were collected. Median follow-up was 4.6 [1; 11] months. Sixty-seven patients were included (median age was 63 ± 14 years; 64% were female, 87% had at least one cardiovascular risk factor). Median time from anti-cancer therapy to CTRD was 41 [10; 141] months. Breast cancer (45%) and lymphoma (39%) were the most frequent neoplasm, 31% had metastatic disease, and all patients were treated with combination antitumor therapy (70% with anthracyclines). Thirtynine per cent of patients had received thoracic radiotherapy. Baseline median LVEF was 33 [27; 37], and 21% had atrial fibrillation. Eighty-five per cent were on beta-blocker therapy and 76% on mineralocorticoid receptor antagonists; 90% of the patients were symptomatic NYHA functional class ≥II. Maximal sacubitril/valsartan titration dose was achieved in 8% of patients (50 mg b.i.d.: 60%; 100 mg b.i.d.: 32%). Sacubitril/valsartan was discontinued in four patients (6%). Baseline Nterminal pro-B-type natriuretic peptide levels (1552 pg/mL [692; 3624] vs. 776 [339; 1458]), functional class (2.2 ± 0.6 vs. 1.6 ± 0.6), and LVEF (33% [27; 37] vs. 42 [35; 50]) improved at the end of follow-up (all P values ≤0.01). No significant statistical differences were found in creatinine (0.9 mg/dL [0.7; 1.1] vs. 0.9 [0.7; 1.1]; P = 0.055) or potassium serum levels (4.5 mg/dL [4.1; 4.8] vs. 4.5 [4.2; 4.8]; P = 0.5). Clinical, echocardiographic, and biochemical improvements were found regardless of the achieved sacubitril–valsartan dose (low or medium/high doses). Conclusions Our experience suggests that sacubitril/valsartan is well tolerated and improves echocardiographic functional and structural parameters, N-terminal pro-B-type natriuretic peptide levels, and symptomatic status in patients with CTRCD.This study was funded by the Instituto de Salud Carlos III, Ministerio de Ciencia, Innovación y Universidades, Spain, and the EU—European Regional Development Fund, by means of a competitive call for excellence in research projects (PIE14/00066) as well as by the Spanish Cardiovascular Network (CIBERCV)

    The informational role of thin options markets: Empirical evidence from the Spanish case

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    This study investigates the informational role of thin options markets, specifically the Spanish options market. Firstly, we examine the effect of options markets by analysing stock market reaction to earnings news, conditional on the availability of options markets. Secondly, we examine options trading activity before the release of earnings news (including the announcement period). The results show that the impact on prices before the earnings release is significantly bigger when options trading is available. Moreover, the dissemination of earnings news is associated with significant unusual activity in the options market due to informed trading, especially when the earnings surprise is highly good

    Circular dichrosim in photoionization of H2 and D2

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    ABSTRACT: In this work, circular dichroism in H2 (D2) photoionization is studied in detail. We have selected several photon energies for a case study: 19 eV for which only direct ionization to the 1s_g ionization channel is present, 27 eV where autoionization of Q1 doubly excited states takes place, and 32.5 eV for which autoionization from Q1 and doubly excited states and direct ionization to 1s_g and 2p_u channels strongly interfere. The latter case shows clear evidence of different behavior of the photoionization against radiation helicity

    Circular dichroism in photoionization of H2

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    ABSTRACT: Circular dichroism is a consequence of chirality. However, nonchiral molecules can also exhibit it when the measurement itself introduces chirality, e.g., when measuring molecular-frame photoelectron angular distributions. The few such experiments performed on homonuclear diatomic molecules show that, as expected, circular dichroism vanishes when the molecular-frame photoelectron angular distributions are integrated over the polar electron emission angle. Here we show that this is not the case in resonant dissociative ionization of H2 for photons of 30–35 eV, which is the consequence of the delayed ionization from molecular doubly excited states into ionic states of different inversion symmetry
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