Radiation-hydrodynamics simulations of surface convection in low-mass stars: connections to stellar structure and asteroseismology

Radiation-hydrodynamical simulations of surface convection in low-mass stars can be exploited to derive estimates of i) the efficiency of the convective energy transport in the stellar surface layers; ii) the convection-related photometric micro-variability. We comment on the universality of the mixing-length parameter, and point out potential pitfalls in the process of its calibration which may be in part responsible for the contradictory findings about its variability across the Hertzsprung-Russell digramme. We further comment on the modelling of the photometric micro-variability in HD49933 - one of the first main COROT targets.Comment: 6 pages, 5 figures, Proceedings paper of IAU Symposium 25

A thought model for the fracture of brittle solids

Translation of Ein Gedankenmodell für den Zerreißvorgang spröder Körper, published in Zeitschrift für angewandte Mathematik und Mechanik, 13:2, (1933), pp.129-133

Corporate Speech in Citizens United vs. Federal Election Commission

In its January 20th, 2010 decision in Citizens United vs. Federal Election Commission, the United States Supreme Court ruled that certain restrictions on independent expenditures by corporations for political advocacy violate the First Amendment of the Constitution, which provides that “Congress shall make no law […] abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.” Justice Kennedy, writing for the 5-4 majority, held that “[b]y suppressing the speech of manifold corporations, both for-profit and non-profit, the Government prevents their voices and view-points from reaching the public and advising voters on which person or entities are hostile to their interests” (Citizens United vs. Federal Election Commission 558 U.S. 38-9 (2010); emphasis added). Much of the language of the opinion, and some of its reasoning, as this passage illustrates, presupposes that corporations are agents capable of speech, and that it is (at least in part) in the light of this that limitations on political advocacy by corporations are prohibited by the Constitution. While there are other strands in the argument, they are interwoven with the conception of the corporation as agent and speaker, with its voice and its viewpoints. The dissenters on the court objected on precisely this point (among others). Justice Stevens wrote sarcastically in his dissent, joined by Justices Ginsburg, Breyer, and Sotomayor, that “[u]nder the majority’s view, I suppose it may be a First Amendment problem that corporations are not permitted to vote, given that voting is, among other things, a form of speech” (558 U.S. 33 (2010)). Justice Sotomayor suggested in oral argument that the Court’s century-old practice of treating corporations as persons rests on a conceptual mistake. My concern in this essay is not with the question whether the restrictions violate the Constitution. There are many issues that bear on this which will be outside the scope of my discussion. My concern is with the proper conceptual framework for understanding the agency of corporations and corporate speech, and the role that conceptions of these play in the background of the majority’s reasoning. The issue is legal, but it also has philosophical, conceptual and semantic aspects. It will be the latter aspects, and their potential to shed light on legal reasoning, that are my main focus. An adequate framework requires saying what properly speaking the corporation is, how agency is expressed through the corporation, whose agency it is, centrally whether the corporation is an agent or person in its own right, and in what sense it can be said to be capable of speech. I draw on recent work in collective action theory, particularly with respect to the semantics of collective action sentences (Ludwig 2007) and the analysis of the proxy agency in collective action (Ludwig 2014), to show (i) that corporations are neither genuine agents nor (therefore) capable of engaging in genuine speech, (ii) that consequently the First Amendment does not apply to corporations per se, and (iii) that a better understanding of the mechanisms of corporate agency casts doubt on more indirect arguments for extending the First Amendment to “corporate speech” as well

A Model for Managing Crime Scene Examiners

Police forces in the UK employ specially trained Crime Scene Examiners (CSEs) to provide forensic science support to the investigation of crime. Previous research (Bradbury and Feist 2005; Williams 2004) has shown wide variations in the management, deployment, and performance of this staff group and, as such, there is a need to develop performance indicators as a measure of effectiveness. This paper looks at the performance and management of CSEs in Durham Constabulary and discusses a model which focuses on the quality of the work of CSEs rather than the quantity of scenes visited, fingermarks lifted or DNA samples collected. Durham Constabulary focus on three main areas of performance to manage their crime scene examiners: level of activity, quality of materials collected, and the conversion of forensic materials into intelligence matches. In this paper we explore a model of performance management which demonstrates how activity measures and review processes can be implemented and utilised to provide insight into the effectiveness of forensic science. Performance management data collected from 24 CSEs over a one-year period (January to December 2011) is used to discuss the role of forensic performance measures in a scientific support unit, reflecting on the strengths and weaknesses of the measures collected

On the incomputability of computable dimension

Using an iterative tree construction we show that for simple computable subsets of the Cantor space Hausdorff, constructive and computable dimensions might be incomputable

Proxy Assertion

In proxy assertion an individual or group asserts something through a spokesperson. The chapter explains proxy assertion as resting on the assignment of a status role to a person (that of spokesperson) whose utterances acts in virtue of that role have the status function of signaling that the principal is committed in a way analogous to an individual asserting that in his own voice. The chapter briefly explains how status functions and status roles are grounded and then treats, in turn, the case of a spokesperson for an individual and a group and the differences in the significance of what the spokesperson does in each case. Finally, it reviews complications introduced by spokesperson autonomy, where the spokesperson is given leave to represent her principal’s views or positions in her own words and to respond to questions on his behalf