Improved Sequential Stopping Rule for Monte Carlo Simulation

This paper presents an improved result on the negative-binomial Monte Carlo technique analyzed in a previous paper for the estimation of an unknown probability p. Specifically, the confidence level associated to a relative interval [p/\mu_2, p\mu_1], with \mu_1, \mu_2 > 1, is proved to exceed its asymptotic value for a broader range of intervals than that given in the referred paper, and for any value of p. This extends the applicability of the estimator, relaxing the conditions that guarantee a given confidence level.Comment: 2 figures. Paper accepted in IEEE Transactions on Communication

M&AS performance in the European financial industry

This paper looks at the performance record of M&As that took place in the European Union financial industry in the period 1998-2002. First, the paper reports evidence on shareholder returns from mergers. Merger announcements brought positive excess returns to the shareholders of the target company around the date of the announcement, with a slight positive excess return in the 3-month period prior to announcement. Returns to shareholders of the acquiring firms were essentially zero around announcement. One year after the announcement, excess returns were not significantly different from zero for either targets or acquirers. The paper also provides evidence on changes in operating performance for the subsample of mergers involving banks. M&As usually involved targets with lower-than-average operating performance for their sector. The transactions resulted in significant improvements in the target banks' performance, beginning on average two years after the transaction was completed. Return on equity of the target companies increased by an average of 7%, and the same firms also experienced efficiency improvements.mergers and acquisitions; financial industry;

Value creation in European M&As.

This paper looks at the value generated to shareholders by the announcement of mergers and acquisitions involving firms in the European Union. Target firm shareholders receive on average a statistically significant excess return of 9%. Acquirers' excess returns are null on average. Excess returns differ significantly depending on whether the merger involves two firms from the same European country or is a cross-border transaction. Cross-border transactions generate less total value than national mergers. Furthermore, when a cross-border merger occurs in an industry in which governments historically have been actively involved, the transaction results in a net destruction of value to shareholders.Cross-border mergers; shareholder returns; value creation; regulation

Integración y consolidación en el sistema financiero europeo

Este artículo ofrece un panorama de la evolución de la actividad de fusiones y adquisiciones en el sector financiero europeo en el período transcurrido desde la introducción de la moneda única y analiza sus implicaciones sobre el grado de integración del sistema financiero europeo y sobre la rentabilidad, evaluada a distintos horizontes, de las empresas involucradas en los procesos de fusión. La actividad de fusiones y adquisiciones se ha caracterizado por un claro predominio de las operaciones de consolidación de carácter nacional, de modo que, hasta fechas recientes, han sido muy escasas las grandes operaciones de reestructuración transfronteriza. El análisis de la reacción del mercado ante los anuncios de fusión no revela una generación de valor neta alrededor de los anuncios. Sí se detecta, sin embargo, una transferencia de valor desde los accionistas de las empresas compradoras a los de las empresas adquiridas. Tampoco se aprecia una diferencia significativa en la creación de valor entre operaciones nacionales e internacionales, lo que sugiere que aun cuando la existencia de diversas barreras a las operaciones de consolidación internacional ha podido disuadir de su realización en algunos casos, las que finalmente se han anunciado no han sido, en promedio, peor valoradas por el mercado que las operaciones de carácter nacional.Fusiones y adquisiciones; Sistema financiero; Operaciones transfronterizas;

Semiempirical Study of Geometries and Valence Isomerization of Pyrene-4,5-oxide and Pyrene-2,3-oxide, Their Oxepines and Related Compounds

A conformational Study of the energies and geometries of the stable compounds obtained from pyrene via enzymatic treatment with oxygen has been carried out using two semiempirical quantum mechanical methods: AM1 and MNDO. The energies of the two possible isomers are strongly dependent upon the spatial position of the oxygen of the pyrene molecule. The valence isomerization of pyrene-4,5-oxide and pyrene-2,3-oxide and their oxepine is discused and related to AM1 and MNDO calculations

Ni-Co Alloy and Multisegmented Ni/Co Nanowire Arrays Modulated in Composition: Structural Characterization and Magnetic Properties

Design of novel multisegmented magnetic nanowires can pave the way for the next generation of data storage media and logical devices, magnonic crystals, or in magneto-plasmonics, among other energy conversion, recovery, and storage technological applications. In this work, we present a detailed study on the synthesis, morphology, structural, and magnetic properties of Ni, Co, and Ni-Co alloy and multisegmented Ni/Co nanowire

Theoretical Study of the Effect Exerted on the Periphery of 10-Annulene by Two Benzenoid Rings

A conformational Study of the energies and geometries of two di-benzo [10]-annulenes, their methylated derivatives and their corresponding bridged valence isomers has been carried out by the semiempirical molecular orbital method AM1. The relative energies of these compounds are strongly dependent on the relative positions of the two benzenoid rings. Interconversions into the corresponding dehydroannulenes were studied. The respective transformations into the corresponding polycyclic benzenoid hydrocarbons were also analyzed

Reproductive history before and after HIV diagnosis: A cross-sectional study in HIV-positive women in Spain

The aim of this study is to examine the reproductive history of human immunodeficiency virus (HIV)-positive women, before and after HIV diagnosis, to describe the characteristics of women with pregnancies after HIV diagnosis, and to assess the prevalence of mother-to-child transmission. A cross-sectional study was performed among women within reproductive ages (18–49) selected from the cohort in the Spanish AIDS Research Network (CoRIS). A descriptive analysis of the pregnancy outcomes was made according to women’s serostatus at the moment of pregnancy and association of women’s characteristics with having pregnancy after HIV diagnosis was evaluated using logistic regression models. Overall, 161 women were interviewed; of them, 86% had been pregnant at least once and 39% after HIV diagnosis. There were 347 pregnancies, 29% of them occurred after HIV diagnosis and in these, 20% were miscarriages and 29% were voluntary termination of pregnancy. There were 3 cases of mother-to-child transmission among the 56 children born from HIV-positive mothers; in these cases, women were diagnosed during delivery. Having a pregnancy after HIV diagnosis was more likely when the younger women were at the time of diagnosis: odds ratio (OR)=1.29 (95% confidence interval 0.40–4.17) for 25 to 29 years old, OR=0.59 (0.15–2.29) for 30 to 34 years old, OR=0.14 (0.03–0.74) for ≥35 years old, compared with thosediagnosis, who were diagnosed for ≥5 years (OR=5.27 [1.71–16.18]), who received antiretroviral treatment at some point (OR=9.38 [1.09–80.45]), and who received information on reproductive health (OR=4.32 [1.52–12.26]). An important number of pregnancies occurred after HIV diagnosis, reflecting a desire for motherhood in these women.Reproductive and sexual health should be tackled in medical follow-ups

Proyecto PREDIRCAM 2. Análisis preliminar de uso y valoración de la plataforma

En la actualidad, la prevalencia de las enfermedades no transmisibles (Non-communicable diseases NCD) y la cantidad de muertes causadas por éstas es muy elevada, en su mayoría, consecuencia del envejecimiento de la población, el aumento de la obesidad y los hábitos de vida sedentarios. En este trabajo se describen el funcionamiento y los resultados preliminares del proyecto Predircam 2, destinado al desarrollo y validación de una plataforma inteligente de tecnologías biomédicas para la monitorización, prevención y tratamiento personalizados del sobrepeso, la obesidad y la prevención de enfermedades asociadas como la diabetes, hipertensión arterial o alteraciones del metabolismo lipídico. El objetivo de este trabajo es presentar los resultados preliminares del análisis del uso de la plataforma, la evaluación de la usabilidad y la valoración de la atención recibida por los pacientes en relación a los profesionales sanitarios