Passive tracers in a general circulation model of the Southern Ocean

Passive tracers are used in an o?-line version of the United Kingdom Fine Resolution Antarctic Model (FRAM) to highlight features of the circulation and provide information on the inter-ocean exchange of water masses. The use of passive tracers allows a picture to be built up of the deep circulation which is not readily apparent from examination of the velocity or density ®elds. Comparison of observations with FRAM results gives good agreement for many features of the Southern Ocean circulation. Tracer distributions are consistent with the concept of a global ``conveyor belt'' with a return path via the Agulhas retro¯ection region for the replenishment of North Atlantic Deep Water

The dominant X-ray wind in massive star binaries

We investigate which shocked wind is responsible for the majority of the X-ray emission in colliding wind binaries, an issue where there is some confusion in the literature, and which we show is more complicated than has been assumed. We find that where both winds rapidly cool (typically close binaries), the ratio of the wind speeds is often more important than the momentum ratio, because it controls the energy flux ratio, and the faster wind is generally the dominant emitter. When both winds are largely adiabatic (typically long-period binaries), the slower and denser wind will cool faster and the stronger wind generally dominates the X-ray luminosity.Comment: 4 pages, 1 figure, accepted by A&A Letter

Semisimple characters for p-adic classical groups

Let G be a unitary, symplectic, or orthogonal group over a non-Archimedean local field of residual characteristic different from 2, considered as the fixed-point subgroup in a general linear group of an involution. Following previous work of Bushnell and Kutzko, and of the author, we generalize the notion of a semisimple character for and for G. In particular, following the formalism of Bushnell and Henniart, we show that these semisimple characters have certain functorial properties. Finally, we show that any positive level supercuspidal representation of G contains a semisimple character

Higher cotangent cohomology of rational surface singularities

The cotangent cohomology groups T^1 and T^2 play an important role in deformation theory, the first as space of infinitesimal deformations, while the obstructions land in the second. Much work has been done to compute their dimension for rational surface singularities. For such singularities we give explicit dimension formulas for the groups T^i with i>2.Comment: 15 page

In Whitehall, academic research is far more likely to be used if it fits with the story already being told

After a six-month spell as a Whitehall policy adviser, Professor Alex Stevens finds there is plenty of evidence on which to base policy – but this does not make for ‘evidence-based’ policy

Are women the key to sustainable development?

This repository item contains a single issue of Sustainable Development Insights, a series of short policy essays that began publishing in 2008 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future. The series seeks to promote a broad interdisciplinary dialogue on how to accelerate sustainable development at all levels.This issue explores the possible link between advances in achieving gender equality and advances in achieving sustainable development goals. The paper concludes, “As indicated by both theory and evidence, the lack of progress on gender equality may be at the heart of the failure to advance on sustainable development. If women were in more productive and decision-making roles, we could be moving faster and more assuredly towards sustainability in the economic, social and environmental sense. Sustainable development is a political concept because it is about good governance, which will be hard to achieve until we get closer to gender parity. Research is needed to test the hypothesis that women are more risk-averse than men and that women leaders would be more apt to follow sustainable development pathways. Given the importance of gender to sustainability, these issues should feature more prominently in sustainable development discussions and be highlighted in a 2012 UN Conference on Sustainable Development.