Private benefits extraction in closely-held corporations: The case for multiple large shareholders*

This paper investigates how multiple large shareholders share control and extract private benefits in closely-held corporations. We find that ownership structures with multiple large shareholders are common and very stable. Moreover, they seem to be, to a large extent, exogenously given. The structure of the controlling group of shareholders has a very significant impact on performance. Performance improves as the control group’s ownership stake increases and, for a given ownership stake, as the number of members increases. The economic significance of the effects indicates that minority expropriation is a very important problem in closely-held firms.

Exploring the link between employment search time and reservation wages in Southern Europe

In our piece of work we are facing a two-fold problem: on the one hand, we study the behaviour of job seekers and the extent to which reservation wages and unemployment benefits play a relevant role in the transition into working life. On the other hand, we intend to find out whether the determinants of the job search process may also affect subsequent wages.transiciones laborales, prestaciones por desempleo, salarios de reserva, ganancias,earnings, transitions into work, unemployment benefits, reservation wages.

A characterization of dual quermassintegrals and the roots of dual steiner polynomials

For any $I\subset\mathbb{R}$ finite with $0\in I$, we provide a characterization of those tuples $(\omega_i)_{i\in I}$ of positive numbers which are dual querma\ss integrals of two star bodies. It turns out that this problem is related to the moment problem. Based on this relation we also get new inequalities for the dual querma\ss integrals. Moreover, the above characterization will be the key tool in order to investigate structural properties of the set of roots of dual Steiner polynomials of star bodies

Salt effect on sensitized photooxidations. A kinetic approch to environmental decomposition of marine contaminants

The salt effect on the kinetics of singlet molecular oxygen [O2(1Δg)]-mediated photooxidations of sea water contaminants was investigated. Two families of photooxidizable compounds were employed in the study: anthracene derivatives and phenols. The presence of salt (NaCl in H2O and LiCl in MeCN, in both cases in the range 0-0.45 M) produces changes in the photooxidation rate. For solvent-polarity-dependent reactions, this behavior can be predicted, by knowing the solvent-polarity dependence of the rate constant for chemical reaction of the substrates with O2(1Δ g) in non-saline solutions (kr). For the cases of photooxidations possessing solvent-polarity-independent or scantily-dependent kr values, the photooxidation rates decrease as the salt content in the solution increases, mainly due to a predominance of the physical quenching pathway. In addition, the quantum yield for O2(1 Δg) generation (ΦΔ) was determined in a series of saline solutions, in the range of 0-0.45 M in water and MeCN solutions, in the presence of NaCl and LiCl respectively. The Δ values are independent, within the experimental error on the salt content.No disponibl

Relationship between Ocular Surface Alterations and Concentrations of Aerial Particulate Matter

Purpose: To evaluate ocular surface alterations in two populations at different exposure levels to particulate matter (PM) in their living and work environments. Methods: A cross-sectional study was conducted, including 78 volunteers from Argentina who lived and worked under different pollution levels in an urban (U; n = 44) or industrial zone (I; n = 34). Mean exposure level to PM was evaluated. Responses to the Ocular Symptom Disease Index and McMonnies questionnaire were obtained from all subjects. Subsequently, an assessment through the Schirmer I test (ST), slit lamp microscopy, vital staining, and tear breakup time was conducted. Statistical analyses with Chi-square and Bartlett’s tests, as well as Student’s t-tests and principal component analysis (PCA), were performed. Results: Particles of size < 2.5 μm (PM2.5) level was significantly higher in the I group than the U group (P = 0.04). Ocular surface parameters including bulbar redness, eyelid redness, and the degree of vital staining with fluorescein (SF) and lissamine green (SLG) exhibited difference between the groups. With regards to the tear film, statistically significant differences in the ST value and meibomian gland dysfunction between the groups were detected (P = 0.003 and P = 0.02, respectively). Conjunctival SF and SLG, and ST values were identified as factors which could distinguish groups exposed to different PM levels. Conclusion: Subjects exposed to higher levels of PM in the outdoor air presented greater ocular surface alterations. Thus, ST, SF, and SLG values could be used as convenient indicators of adverse health effects due to exposure to air pollution

Projection based ensemble learning for ordinal regression

The classification of patterns into naturally ordered labels is referred to as ordinal regression. This paper proposes an ensemble methodology specifically adapted to this type of problems, which is based on computing different classification tasks through the formulation of different order hypotheses. Every single model is trained in order to distinguish between one given class (k) and all the remaining ones, but grouping them in those classes with a rank lower than k, and those with a rank higher than k. Therefore, it can be considered as a reformulation of the well-known one-versus-all scheme. The base algorithm for the ensemble could be any threshold (or even probabilistic) method, such as the ones selected in this paper: kernel discriminant analysis, support vector machines and logistic regression (all reformulated to deal with ordinal regression problems). The method is seen to be competitive when compared with other state-of-the-art methodologies (both ordinal and nominal), by using six measures and a total of fifteen ordinal datasets. Furthermore, an additional set of experiments is used to study the potential scalability and interpretability of the proposed method when using logistic regression as base methodology for the ensemble

Borderline kernel based over-sampling

Nowadays, the imbalanced nature of some real-world data is receiving a lot of attention from the pattern recognition and machine learning communities in both theoretical and practical aspects, giving rise to di erent promising approaches to handling it. However, preprocessing methods operate in the original input space, presenting distortions when combined with kernel classi ers, that operate in the feature space induced by a kernel function. This paper explores the notion of empirical feature space (a Euclidean space which is isomorphic to the feature space and therefore preserves its structure) to derive a kernel-based synthetic over-sampling technique based on borderline instances which are considered as crucial for establishing the decision boundary. Therefore, the proposed methodology would maintain the main properties of the kernel mapping while reinforcing the decision boundaries induced by a kernel machine. The results show that the proposed method achieves better results than the same borderline over- sampling method applied in the original input spac

A Practical Environment to Apply Model-Driven Web Engineering

The application of a model-driven paradigm in the development of Web Systems has yielded very good research results. Several research groups are defining metamodels, transformations, and tools which offer a suitable environment, known as model-driven Web engineering (MDWE). However, there are very few practical experiences in real Web system developments using real development teams. This chapter presents a practical environment of MDWE based on the use of NDT (navigational development techniques) and Java Web systems, and it provides a practical evaluation of its application within a real project: specialized Diraya.Ministerio de Educación y Ciencia TIN2007-67843-C06-03Ministerio de Educación y Ciencia TIN2007-30391-

Nuevas aportaciones al estudio polínico de sedimentos del Parque Natural de los Alcornocales (Cádiz, sur de España)

Nuevas apotaciones al estudio polínico de sedimentos del Parque Natural de los Alcornocales (Cádiz, Sur de España). En este trabajo se completa el contenido polínico de una columna de sedimento de 300 cm, extraida de una zona semiturbosa de la Sierra del Aljibe en el Parque Natural de los Alcornocales (Cádiz). Se discuten las variaciones polínicas porcentuales de los taxones identificados, consideradas de nuevo aquí a la luz de los nuevos datos, fundamentalmente la datación con radiocarbono, y se interpretan los diagramas polínicos resultantes en términos paleoecológicos. Por otro lado, y en base a estudios previos en el norte de Marruecos, zona de características ecológicas e históricas similares a la zona estudiada, se concluye el uso diferente del territorio a ambos lados del estrecho