How Bob Laughlin Tamed the Giant Graviton from Taub-NUT space

In this paper we show how two dimensional electron systems can be modeled by strings interacting with D-branes. The dualities of string theory allow several descriptions of the system. These include descriptions in terms of solitons in the near horizon D6-brane theory, non-commutative gauge theory on a D2-brane, the Matrix Theory of D0-branes and finally as a giant graviton in M-theory. The soliton can be described as a D2-brane with an incompressible fluid of D0-branes and charged string-ends moving on it. Including an NS5 brane in the system allows for the existence of an edge with the characteristic massless chiral edge states of the Quantum Hall system.Comment: 26 pages, 4 figures, discussions adde

Near-IR Spectroscopy of a Young Super-Star Cluster in NGC 6946: Chemical Abundances and Abundance Patterns

Using the NIRSPEC spectrograph at Keck II, we have obtained H and K-band echelle spectra for a young (10-15 Myr), luminous (MV=-13.2) super-star cluster in the nearby spiral galaxy NGC 6946. From spectral synthesis and equivalent width measurements we obtain for the first time accurate abundances and abundance patterns in an extragalactic super-star cluster. We find [Fe/H]=-0.45+/-0.08 dex, an average alpha-enhancement of +0.22+/-0.1 dex, and a relatively low 12C/13C~ 8+/-2 isotopic ratio. We also measure a velocity dispersion of ~9.1 km/s, in agreement with previous estimates. We conclude that integrated high-dispersion spectroscopy of massive star clusters is a promising alternative to other methods for abundance analysis in extragalactic young stellar populations.Comment: 5 pages, incl. 2 figures. Accepted for publication in MNRAS Letters. The definitive version will be available at http://www.blackwell-synergy.co

Towards a general framework for evaluating intelligent environments methodologies

Recent studies reveal that there are different methodologies for developing Intelligent Environments. Thus, it has become essential to scrutinize and evaluate the methodologies to increase our understanding of their strengths, weaknesses and features. However, these concerns have not been the target of recent research efforts. This paper presents an evaluation framework for qualitative evaluation of Intelligent Environment methodologies. It is a step towards standardization of current Intelligent Environments methodologies. The framework has been defined through studying, abstracting and unifying best practices from systems engineering. It is based on a generic life cycle model. As an initial validation, we evaluated the User Centred Intelligent Environment Development Process against the proposed framework. We note that this methodology at its current state presents some limitations which will be addressed in future works

Requirements engineering for intelligent environments

The field of Intelligent Environments (IE) is maturing to a level at which a range of sophisticated applications are emerging. Such systems aim to be context-aware, especially being adaptable to possibly unpredictable circumstances. An area of significant potential is that of ‘ambient assisted living’, with significant advances in fields such as smart spaces, classrooms, and assisted living space for the elderly or people with disabilities. In recent years, however, it has been recognised that numerous IE systems have been developed without adopting best practises from software engineering. The work presented here focuses on the requirements engineering stage and presents a framework for IE systems in which an intrinsic component is context-awareness. Whilst the framework is intended as a general IE model, we are currently applying it to the specific area of ambient assisted living and it is being employed on the POSEIDON project. It is anticipated that such real world application of the model will help endorse its conception and facilitate further refinement of the framework

Towards engineering higher quality intelligent environments: a multi case study approach

This study addresses the need to enhance the quality of Intelligent Environments, recognizing their unique characteristics and the absence of adequate guidance on quality management during development. It pursues three primary objectives: proposing a novel quality-in-use model, presenting an enhanced version of the User-Centered Intelligent Environment Development Process, and reporting on the application of these approaches through a multiple case study. To embed quality into systems, we advocate for the integration of quality characteristics from ISO/IEC 25000 standards with functional requirements. Stakeholders collaboratively define targets using measures from quality standards, and metrics enable early problem detection and resolution during development. The proposed quality-in-use model provides an insightful and objective perspective on system capabilities, guiding development and ensuring stakeholder involvement. However, challenges such as shortening development cycles for early and regular stakeholder feedback and managing an increased number of system tests were noted. Our study makes a significant contribution to the field of Intelligent Environments by providing a structured approach to embedding and managing quality throughout the development lifecycle. The multiple case study offers empirical evidence of the effectiveness of the proposed approaches, with ongoing considerations for challenges in the development process

Quality traceability for user-centric context-aware systems in intelligent environments

Context-awareness is an important component of modern software systems. For example, in Ambient Assisted Living (AAL), the concept of context-awareness empowers users by reducing their dependence on others. Due to this role in healthcare, such systems need to be reliable and usable by their intended users. Our research addresses the development, testing and validation of context-aware systems in an emerging field which currently lacks sufficient systems engineering processes and disciplines. One specific issue being that developers often focus on delivering a system that works at some level, rather than engineering a system that meets a specified set of system requirements and their corresponding qualities. Our research aims to contribute towards improving the delivery of system quality by tracing, developing and linking systems development data for requirements, contexts including sensors, test cases and their results, and user validation tests and their results. We refer to this approach as the “quality traceability of context-aware systems”. In order to support the developer, the quality traceability of context-aware systems introduces a systems development approach tailored to context-aware systems in intelligent environments, an automated system testing tool and system validation process. We have implemented a case study to inform the research. The case study is in healthcare and based on an AAL system used to remotely monitor and manage, in real time, an individual prone to depressive symptoms

Proceedings of a seminar on Future Directions for New Zealand Lamb Marketing

A seminar on lamb marketing was organised to provide a forum for discussion of this important issue, as New Zealand faces significant changes in the lamb marketing environment. The increasing importance of new lamb markets, especially in the Middle East, the importance of the North American market and the increasing fragility of the United Kingdom lamb market, make such discussion very timely. In addition, the market requirement for lambs with a lower fat content has meant that lamb grading standards have been more rigorously set and substantial price schedule penalties have been imposed for over fatness. Increasing production, processing and transportation costs have meant that the farmers share, of the market price for lamb, has fallen. This means that it has become even more important to achieve the maximum possible market return. The achievement of this target must depend on the markets available, the type of marketing activity undertaken in those markets and the structure of the industry supporting the marketing effort. The optimum results may not be available based on the present industry structure and approach and it was therefore considered appropriate that alternatives be reviewed and examined with a view to the future. Includes full text of the papers: Hilgendorf, C. New Zealand lamb marketing: the past and present; Cullwick, T.D.C. The need for a global marketing strategy for lamb and lamb products

Phylogenetic conservation of soil bacterial responses to simulated global changes.

Soil bacterial communities are altered by anthropogenic drivers such as climate change-related warming and fertilization. However, we lack a predictive understanding of how bacterial communities respond to such global changes. Here, we tested whether phylogenetic information might be more predictive of the response of bacterial taxa to some forms of global change than others. We analysed the composition of soil bacterial communities from perturbation experiments that simulated warming, drought, elevated CO2 concentration and phosphorus (P) addition. Bacterial responses were phylogenetically conserved to all perturbations. The phylogenetic depth of these responses varied minimally among the types of perturbations and was similar when merging data across locations, implying that the context of particular locations did not affect the phylogenetic pattern of response. We further identified taxonomic groups that responded consistently to each type of perturbation. These patterns revealed that, at the level of family and above, most groups responded consistently to only one or two types of perturbations, suggesting that traits with different patterns of phylogenetic conservation underlie the responses to different perturbations. We conclude that a phylogenetic approach may be useful in predicting how soil bacterial communities respond to a variety of global changes. This article is part of the theme issue 'Conceptual challenges in microbial community ecology'