The Stable Core and Dynamic Periphery in Top Management Teams

This study explores how top management teams make strategic decisions. The findings indicate that the top management team performs a variety of monitoring and control functions within most firms, but that a single team with stable composition does not make strategic choices in most organizations. Instead, different groups, with members from multiple organizational levels, form to make various strategic decisions. A stable subset of the top team forms the core of each of these multiple decision‐making bodies. The findings offer a possible explanation for inconsistent findings in the top management team literature, and suggest several new directions for future senior team research

Gravitational entropy of cosmic expansion

We apply a recent proposal to define "gravitational entropy" to the expansion of cosmic voids within the framework of non-perturbative General Relativity. By considering CDM void configurations compatible with basic observational constraints, we show that this entropy grows from post-inflationary conditions towards a final asymptotic value in a late time fully non-linear regime described by the Lemaitre-Tolman-Bondi (LTB) dust models. A qualitatively analogous behavior occurs if we assume a positive cosmological constant consistent with a $\Lambda$-CDM background model. However, the $\Lambda$ term introduces a significant suppression of entropy growth with the terminal equilibrium value reached at a much faster rate.Comment: 5 Pages, 2 figures, AN style. Contribution to Proceedings of the Second Caribbean Symposium on Nuclear and Astroparticle Physics (STARS 2013), La Habana, Cuba, 5-9 May 201

Why Catastrophic Organizational Failures Happen

Excerpt from the introduction: The purpose of this chapter is to examine the major streams of research about catastrophic failures, describing what we have learned about why these failures occur as well as how they can be prevented. The chapter begins by describing the most prominent sociological school of thought with regard to catastrophic failures, namely normal accident theory. That body of thought examines the structure of organizational systems that are most susceptible to catastrophic failures. Then, we turn to several behavioral perspectives on catastrophic failures, assessing a stream of research that has attempted to understand the cognitive, group and organizational processes that develop and unfold over time, leading ultimately to a catastrophic failure. For an understanding of how to prevent such failures, we then assess the literature on high reliability organizations (HRO). These scholars have examined why some complex organizations operating in extremely hazardous conditions manage to remain nearly error free. The chapter closes by assessing how scholars are trying to extend the HRO literature to develop more extensive prescriptions for managers trying to avoid catastrophic failures

Quasi-local variables and scalar averaging in LTB dust models

We introduce quasi--local (QL) scalar variables in spherically symmetric LTB models. If the QL scalars are defined as functionals, they become weighed averages that generalize the standard proper volume averages on space slices orthogonal to the 4-velocity. We examine the connection between QL functions and functionals and the "back-reaction" term $Q$ in the context of Buchert's scalar averaging formalism. With the help of the QL scalars we provide rigorous proof that back--reaction is positive for (i) all LTB models with negative and asymptotically negative spatial curvature, and (ii) models with positive curvature decaying to zero asymptotically in the radial direction. We show by means of qualitative, but robust, arguments that generic LTB models exist, either with clump or void profiles, for which an "effective" acceleration associated with Buchert's formalism can mimic the effects of dark energy.Comment: Submitted contribution for the proceedings of the "Invisible Universe Internationale Confernce", Palais de L'UNESCO, Paris, France, June 29-July 3, 2009. Jean-Michel ALIMI, editor. 10 pages, 2 figures. AIP macros: layoutstyle 8x11singl

Cosmic rays of leptons from Pulsars and Supernova Remnants

The latest results from PAMELA and FERMI experiments confirm the necessity to improve theoretical models of production and propagation of galactic electrons and positrons. There are many possible explanations for the positron excess observed at energies larger than 10 GeV and for some features around 1 TeV in the total flux of electrons and positrons. Supernovae are astrophysical objects with the potential to explain these observations. In this work, we present an updated study of the astrophysical sources of lepton cosmic rays and the possible and the possible explanation of the anomalies in terms of astrophysical sources.Comment: 6 pages, 1 figures, Proceeding for the Conference on Cosmic Rays for Particle and Astroparticle Physics, CRICATPP 2010, Como, Ital