Variability and polarization in the inner jet of 3C395

We present new results on the parsec-scale jet of the quasar 3C395, derived from VLBI polarization sensitive observations made in 1995.91 and 1998.50 at 8.4, 15.4 and 22.2 GHz. The observations show a complex one-sided jet extending up to 20 mas, with a projected magnetic field essentially aligned with the radio jet. The emission is strongly dominated, in total intensity and polarization, by the core and the inner jet region (of ~3 mas length). We have studied the details of this dominant region finding clear structural variations during this ~2.5 years period, in contrast with the apparent quietness of the jet structure inferred from lower resolution VLBI observations. We observe the ejection of a new component from the core and variations in the degree of polarization of the inner jet components. We estimate a high Faraday Rotation Measure close to the core, with a strong decrease along the inner jet.Comment: 7 pages, 4 figures, A&A in pres

THE PROBLEM OF SOVEREIGNTY, INTERNATIONAL LAW, AND INTELLECTUAL CONSCIENCE

The concept of sovereignty is a recurring and controversial theme in international law, and it has a long history in western philosophy. The traditionally favored concept of sovereignty proves problematic in the context of international law. International law’s own claims to sovereignty, which are premised on traditional concept of sovereignty, undermine individual nations’ claims to sovereignty. These problems are attributable to deep-seated flaws in the traditional concept of sovereignty. A viable alternative concept of sovereignty can be derived from key concepts in Friedrich Nietzsche’s views on human reason and epistemology. The essay begins by considering the problem of sovereignty from the ancient philosophical perspective inherent in the fundamental assumptions and ideas of Plato’s political philosophy and epistemology. It then considers the contemporary problem of sovereignty in the context of international law by examining Louis Henkin’s formulation of and approach to it in his essay That S-Word: Sovereignty, and Globalization, and Human Rights, Etc. Finally, the essay articulates Nietzsche’s views on intellectual conscience, discusses their merits and advantages when used in dealing the problem of sovereignty in the context of international law, and proposes a solution to this problem that draws on the philosophies of Nietzsche, Novalis, Kant and Plato. The essay illustrates the relevance and advantages of this solution by examining the issue of states’ reservations to international treaties and conventions

High-energy emission from Gamma-Ray Bursts

The number of Gamma-Ray Bursts (GRBs) detected at high energies ($\sim\,0.1-100$ GeV) has seen a rapid increase over the last decade, thanks to observations from the Fermi-Large Area Telescope. The improved statistics and quality of data resulted in a better characterisation of the high-energy emission properties and in stronger constraints on theoretical models. In spite of the many achievements and progresses, several observational properties still represent a challenge for theoretical models, revealing how our understanding is far from being complete. This paper reviews the main spectral and temporal properties of $\sim\,0.1-100$ GeV emission from GRBs and summarises the most promising theoretical models proposed to interpret the observations. Since a boost for the understanding of GeV radiation might come from observations at even higher energies, the present status and future prospects for observations at very-high energies (above $\sim$ 100 GeV) are also discussed. The improved sensitivity of upcoming facilities, coupled to theoretical predictions, supports the concrete possibility for future ground GRB detections in the high/very-high energy domain.Comment: Invited review article, IJMPD (in press

Influences of Accent and Ethnic Background on Perceptions of Eyewitness Testimony

The purpose of the present work was to investigate the effect two eyewitness factors, accent and ethnic background, have on the perceived favorability of eyewitness testimony and case disposition in criminal trials. Six variations of testimony were created and videotaped. The videotapes varied by accent and ethnic background of the eyewitness; the testimony text was identical. Four eyewitness favorability variables, a) credibility, b) judgment of accuracy, c) deceptiveness, and d) prestige, as well as their relationship to case disposition, were measured. One hundred seventy-four undergraduate participants viewed one of the six videotapes. Results indicate that there was a significant main effect of accent for the four eyewitness favorability variables. Accent by ethnic background interactions also yielded significant findings for the four variables as well as for the defendant’s degree of guilt. Results were interpreted using the Elaboration Likelihood Model. The potential importance of these results for judicial settings is discussed