A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279

It is widely accepted that strong and variable radiation detected over all accessible energy bands in a number of active galaxies arises from a relativistic, Doppler-boosted jet pointing close to our line of sight. The size of the emitting zone and the location of this region relative to the central supermassive black hole are, however, poorly known, with estimates ranging from light-hours to a light-year or more. Here we report the coincidence of a gamma-ray flare with a dramatic change of optical polarization angle. This provides evidence for co-spatiality of optical and gamma-ray emission regions and indicates a highly ordered jet magnetic field. The results also require a non-axisymmetric structure of the emission zone, implying a curved trajectory for the emitting material within the jet, with the dissipation region located at a considerable distance from the black hole, at about 10^5 gravitational radii.Comment: Published in Nature issued on 18 February 2010. Corresponding authors: Masaaki Hayashida and Greg Madejsk

Mobility justice in low carbon energy transitions

Mobility systems raise multiple questions of justice. Work on mobility justice and policy often treats different elements of the debate separately, for example focussing on environmental justice or accessibility. This is problematic as it can privilege policy solutions without a full view of the winners and losers and the values implicit in that. Using analysis of current policy, we investigate how mobility justice can reconcile its different components, and find two major consequences. First, is doubt about the justice of the existing policy approach which tries to tackle transport pollution primarily through a shift to low emission vehicles. This approach privileges those with access to private vehicles and further privileges certain sets of activities. Second is a need to reassess which basic normative ideas should be applied in mobility justice. Work on mobility justice has tended to appeal to conceptions of justice concerned with access to resources including resources enabling mobility. These conceptions say little about how resources should be used. We show that avoiding stark inequalities means collectively thinking about how resources are used, about how we value activities involving mobility, and about what sorts of goods and services we create

Using an Ecological Ethics Framework to Make Decisions about the Relocation of Wildlife

Relocation is an increasingly prominent conservation tool for a variety of wildlife, but the technique also is controversial, even among conservation practitioners. An organized framework for addressing the moral dilemmas often accompanying conservation actions such as relocation has been lacking. Ecological ethics may provide such a framework and appears to be an important step forward in aiding ecological researchers and biodiversity managers to make difficult moral choices. A specific application of this framework can make the reasoning process more transparent and give more emphasis to the strong sentiments about non-human organisms held by many potential users. Providing an example of the application of the framework may also increase the appeal of the reasoning process to ecological researchers and biodiversity managers. Relocation as a conservation action can be accompanied by a variety of moral dilemmas that reflect the interconnection of values, ethical positions, and conservation decisions. A model that is designed to address moral dilemmas arising from relocation of humans provides/demonstrates/illustrates a possible way to apply the ecological ethics framework and to involve practicing conservationists in the overall decision-making process

Gender Diversity in the Boardroom and Risk Management: A Case of R&D Investment

Increasing gender diversity in the boardroom has been promoted as a way to enhance corporate governance and risk management. This study empirically examines whether boards with more female directors play a role in reducing R&D risk. We first show that female directors help to reduce the positive relationship between R&D investment and future performance volatility. We then report that firms with more gender-diverse boards exhibit a lower adverse effect of R&D on the cost of debt. These results are robust to endogeneity analysis, alternative measures of gender diversity and risky investment, and other sensitivity tests. Overall, our results suggest that female directors improve board effectiveness in risk management with respect to R&D investment