Laser-driven proton scaling laws and new paths towards energy increase

The past few years have seen remarkable progress in the development of laser-based particle accelerators. The ability to produce ultrabright beams of multi-megaelectronvolt protons routinely has many potential uses from engineering to medicine, but for this potential to be realized substantial improvements in the performances of these devices must be made. Here we show that in the laser-driven accelerator that has been demonstrated experimentally to produce the highest energy protons, scaling laws derived from fluid models and supported by numerical simulations can be used to accurately describe the acceleration of proton beams for a large range of laser and target parameters. This enables us to evaluate the laser parameters needed to produce high-energy and high-quality proton beams of interest for radiography of dense objects or proton therapy of deep-seated tumours.

Shaping the Future of Mental Health Policy and Legislation in Northern Ireland: The Impact of Service User and Professional Social Work Discourses

This paper explores the complex interrelationship between service user and professional social work discourses and provides a critical commentary on their respective contributions to the recent review of mental health policy and legislation in Northern Ireland. The analysis indicates that dominant trends in mental health care, as mediated through service structures and institutional identities, have tended to prioritize the more coercive aspects of the social work role and reinforce existing power inequalities with service users. It is argued that such developments underline the need for a ‘refocusing’ debate in mental health social work to consider how a more appropriate balance can be achieved between its participatory/empowering and regulatory/coercive functions. Whilst highlighting both congruence and dissonance between respective discourses, the paper concludes that opportunities exist within the current change process for service users and social workers to build closer alliances in working together to reconstruct practice, safeguard human rights and develop innovative alternatives to a traditional bio-medical model of treatment.

Area laws and entanglement distillability of thermal states

We study the entanglement distillability properties of thermal states of many-body systems Following the ideas presented in [6, A Ferraro et al., Phys. Rev Lett 100, 080502 (2008)], we first discuss the appearance of bound entanglement in those systems satisfying an entanglement area law Then, we extend these results to other topologies, not necessarily satisfying an entanglement area law We also study whether bound entanglement survives in the macroscopic limit of an infinite number of particles.

Massive MIMO with Non-Ideal Arbitrary Arrays: Hardware Scaling Laws and Circuit-Aware Design

Massive multiple-input multiple-output (MIMO) systems are cellular networks where the base stations (BSs) are equipped with unconventionally many antennas, deployed on colocated or distributed arrays. Huge spatial degrees-of-freedom are achieved by coherent processing over these massive arrays, which provide strong signal gains, resilience to imperfect channel knowledge, and low interference. This comes at the price of more infrastructure; the hardware cost and circuit power consumption scale linearly/affinely with the number of BS antennas N. Hence, the key to cost-efficient deployment of large arrays is low-cost antenna branches with low circuit power, in contrast to today’s conventional expensive and power-hungry BS antenna branches. Such low-cost transceivers are prone to hardware imperfections, but it has been conjectured that the huge degrees-of-freedom would bring robustness to such imperfections. We prove this claim for a generalized uplink system with multiplicative phasedrifts, additive distortion noise, and noise amplification. Specifically, we derive closed-form expressions for the user rates and a scaling law that shows how fast the hardware imperfections can increase with N while maintaining high rates. The connection between this scaling law and the power consumption of different transceiver circuits is rigorously exemplified. This reveals that one can make the circuit power increase as p N, instead of linearly, by careful circuit-aware system design.

Changing policy and legislation in special and inclusive education: a perspective from Northern Ireland

It is now 15 years since the signing of the 1998 Belfast (or ‘Good Friday’) Peace Agreement which committed all participants to exclusively democratic and peaceful means of resolving differences, and towards a shared and inclusive society defined by the principles of respect for diversity, equality and the interdependence of people. In particular, it committed participants to the protection and vindication of the human rights of all. This is, therefore, a precipitous time to undertake a probing analysis of educational reforms in Northern Ireland associated with provision in the areas of inclusion and special needs education. Consequently, by drawing upon analytical tools and perspectives derived from critical policy analysis, this article, by Ron Smith from the School of Education, Queen’s University Belfast, discusses the policy cycle associated with the proposed legislation entitled Every School a Good School: the way forward for special educational needs and inclusion. It examines how this policy text structures key concepts such as ‘inclusion’, ‘additional educational needs’ and ‘barriers to learning’, and how the proposals attempt to resolve the dilemma of commonality and difference. Conceived under direct rule from Westminster (April 2006), issued for consultation when devolved powers to a Northern Ireland Assembly had been restored, and with the final proposals yet to be made public, this targeted educational strategy tells a fascinating story of the past, present and likely future of special needs education in Northern Ireland. Before offering an account of this work, it is placed within some broader ecological frameworks.

Terrorism Laws and Legal Accountability

This chapter explores the extent to which courts can contribute to the countering of terrorism. It suggests that the contribution will depend on the type of actor the courts are attempting to hold to account as well as on the powers that are conferred on courts by national and international legal regimes. It concludes that courts are most legitimate and effective in relation to terrorist suspects and law enforcers, but less so in relation to counter-terrorism operatives and law-makers.

Agriculture, settlement and society in Early Medieval Ireland

During the early medieval period, Ireland was politically organised into a large number of very small kingdoms. Unlike much of Western Europe, it had not been incorporated into the Roman Empire, and as a consequence, settlement remained exclusively rural in character until the Viking period. Extensive documentary, archaeological, zooarchaeological and macro-plant evidence provides a detailed reconstruction of the livestock and arable economy of the period. Cattle ownership formed the basis of wealth as well as being an indicator of status in society, and this is reflected in its clear dominance of the livestock economy during this period. From the eighth century onwards, however, cereal production appears to grow in importance as subsistence farming gave way to the production of agricultural surplus. This is reflected in cereal diversification and in the construction of watermills and more efficient grain-drying kilns. At the same time, settlement underwent significant changes and the relative importance of cattle in some areas began to decline.