Determinants of director compensation in two-tier systems: evidence from German panel data

Building on a unique panel data set of German Prime Standard companies for the period 2005-2008, this paper investigates the influencing factors of both director compensation levels and structure, i.e. the probability of performance-based compensation. Drawing on agency theory arguments and previous literature, we analyze a comprehensive group of determinants, including detailed corporate performance, ownership and board characteristics. While controlling for unobserved heterogeneity, we find director compensation to be set in ways consistent with optimal contracting theory. I.e. compensation is systematically structured to mitigate agency conflicts and to encourage effective monitoring. Thus, our results indicate that similar types of agency conflicts exist in the German two-tier setting. --Director Compensation,Corporate Governance,Outside Directors,Two-tier System,Agency Costs

X-Ray Eclipse Timing in the LMXB EXO0748-676

Orbital period changes are an important diagnostic for understanding low mass X-ray binary (LMXB) accretion-induced angular momentum exchange and overall system evolution. We present our most recent results for the eclipse timing of the LMXB EXO0748-676. Since its discovery in 1985 it has apparently undergone three distinct orbital period "epochs", each characterized by a different orbital period than the previous epoch. We outline the orbital period behavior for EXO0748-676 over the past 18 years and discuss the implications of this behavior in light of current theoretical ideas for LMXB evolution.Comment: 4 Pages, 3 Figures, Submitted to the X-Ray Timing 2003: Rossi and Beyond conference, November 200

Aprender ciencias en y para la comunidad

Durante algún tiempo, he afirmado que la educación científica necesita ser desinstitucionalizada para superar la profunda crisis que atraviesa actualmente. En este artículo describo formas en las cuales se puede pensar y poner en práctica esta desinstitucionalización en la enseñanza de las ciencias y en la práctica del diseño del currículo de ciencias. Se propone la teoría de la actividad como marco para conceptualizar diferentes sistemas de actividad y sus contradicciones. Proporciono ejemplos prácticos de mi actividad de enseñanza de una unidad de activismo ambiental y de mi diseño de un currículo apropiado para pueblos aborígenes a fin de mostrar una educación científica que se sitúa en el mundo diario de la comunidad.For some time now, I have argued that science education needs to be deinstitutionalized to overcome the deep crisis in which it currently finds itself. In the present paper, I outline ways in which such deinstitutionalization may be thought and enacted in science teaching and science curriculum design practice. Activity theory is proposed as a framework to conceptualize different activity systems and their contradictions. Practical examples from my own teaching of an environmental activist unit and designing a curriculum appropriate for indigenous peoples are provided to show a science education that situates itself in the everyday world of the community

Forming the Dusty Ring in HR 4796A

We describe planetesimal accretion calculations for the dusty ring observed in the nearby A0 star HR 4796A. Models with initial masses of 10-20 times the minimum mass solar nebula produce a ring of width 7-15 AU and height 0.3-0.6 AU at 70 AU in roughly 10 Myr. The ring has a radial optical depth of 1. These results agree with limits derived from infrared images and from the excess infrared luminosity.Comment: 6 pages, including 2 figures and 1 table; ApJ Letters, in pres

A Strong X-Ray Burst from the Low Mass X-Ray Binary EXO0748-676

We have observed an unusually strong X-ray burst as a part of our regular eclipse timing observations of the low mass binary system EXO0748-676. The burst peak flux was 5.2x10^-8 ergs cm^-2 s^-1, approximately five times the normal peak X-ray burst flux observed from this source by RXTE. Spectral fits to the data strongly suggest that photospheric radius expansion occurred during the burst. In this Letter we examine the properties of this X-ray burst, which is the first example of a radius expansion burst from EXO0748-676 observed by RXTE. We find no evidence for coherent burst oscillations. Assuming that the peak burst luminosity is the Eddington luminosity for a 1.4 solar mass neutron star we derive a distance to EXO0748-676 of 7.7 kpc for a helium-dominated burst photosphere and 5.9 kpc for a hydrogen-dominated burst photosphere.Comment: 15 pages including 2 figures and 1 table. Accepted for publication in the Astrophysical Journa