Structural and Electronic Properties of the Interface between the High-k oxide LaAlO3 and Si(001)

The structural and electronic properties of the LaAlO3/Si(001) interface are determined using state-of-the-art electronic structure calculations. The atomic structure differs from previous proposals, but is reminiscent of La adsorption structures on silicon. A phase diagram of the interface stability is calculated as a function of oxygen and Al chemical potentials. We find that an electronically saturated interface is obtained only if dopant atoms segregate to the interface. These findings raise serious doubts whether LaAlO3 can be used as an epitaxial gate dielectric.Comment: 4 pages, 5 figure

Simulating a dual beam combiner at SUSI for narrow-angle astrometry

The Sydney University Stellar Interferometer (SUSI) has two beam combiners, i.e. the Precision Astronomical Visible Observations (PAVO) and the Microarcsecond University of Sydney Companion Astrometry (MUSCA). The primary beam combiner, PAVO, can be operated independently and is typically used to measure properties of binary stars of less than 50 milliarc- sec (mas) separation and the angular diameters of single stars. On the other hand, MUSCA was recently installed and must be used in tandem with the for- mer. It is dedicated for microarcsecond precision narrow-angle astrometry of close binary stars. The performance evaluation and development of the data reduction pipeline for the new setup was assisted by an in-house computer simulation tool developed for this and related purposes. This paper describes the framework of the simulation tool, simulations carried out to evaluate the performance of each beam combiner and the expected astrometric precision of the dual beam combiner setup, both at SUSI and possible future sites.Comment: 28 pages, 23 figures, accepted for publication in Experimental Astronomy. The final publication is available at http://link.springer.co

A low cost scheme for high precision dual-wavelength laser metrology

A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology which employs heterodyne detection, the method developed in this work utilizes direct detection of interference fringes of two He-Ne lasers as well as a less precise stepper motor open-loop position control system to perform its measurement. Although the method may be applicable to a variety of circumstances, the specific application where this metrology is essential is in an astrometric optical long baseline stellar interferometer dedicated to precise measurement of stellar positions. In our example application of this metrology to a narrow-angle astrometric interferometer, measurement of nanometer precision could be achieved without frequency-stabilized lasers although the use of such lasers would extend the range of optical path length the metrology can accurately measure. Implementation of the method requires very little additional optics or electronics, thus minimizing cost and effort of implementation. Furthermore, the optical path traversed by the metrology lasers is identical with that of the starlight or science beams, even down to using the same photodetectors, thereby minimizing the non-common-path between metrology and science channels.Comment: 17 pages, 4 figures, accepted for publication in Applied Optic

A signaling visualization toolkit to support rational design of combination therapies and biomarker discovery: SiViT

Targeted cancer therapy aims to disrupt aberrant cellular signalling pathways. Biomarkers are surrogates of pathway state, but there is limited success in translating candidate biomarkers to clinical practice due to the intrinsic complexity of pathway networks. Systems biology approaches afford better understanding of complex, dynamical interactions in signalling pathways targeted by anticancer drugs. However, adoption of dynamical modelling by clinicians and biologists is impeded by model inaccessibility. Drawing on computer games technology, we present a novel visualisation toolkit, SiViT, that converts systems biology models of cancer cell signalling into interactive simulations that can be used without specialist computational expertise. SiViT allows clinicians and biologists to directly introduce for example loss of function mutations and specific inhibitors. SiViT animates the effects of these introductions on pathway dynamics, suggesting further experiments and assessing candidate biomarker effectiveness. In a systems biology model of Her2 signalling we experimentally validated predictions using SiViT, revealing the dynamics of biomarkers of drug resistance and highlighting the role of pathway crosstalk. No model is ever complete: the iteration of real data and simulation facilitates continued evolution of more accurate, useful models. SiViT will make accessible libraries of models to support preclinical research, combinatorial strategy design and biomarker discovery

Positive psychology and career development

Positive psychology has been an influential movement within psychology in the early years of the 21st century. It is now timely to assess the value of its contribution to career education and guidance. This paper provides a critique of this perspective. Positive psychology can enrich approaches to career development. It can provide a fertile source of concepts and an empirical basis for some elements of practice. However the application of approaches derived from positive psychology is problematic if it neglects the socioeconomic context in which careers are lived and experienced, or if claims are made for its efficacy cannot be supported by the evidence base

Towards a capability approach to careers: Applying Amartya Sen's thinking

Amartya Sen’s capability approach characterizes an individual’s well-being in terms of what they are able to be, and what they are able to do. This framework for thinking has many commonalities with the core ideas in career guidance. Sen’s approach is abstract and not in itself a complete or explanatory theory, but a case can be made that the capability approach has something to offer career theory when combined with a life-career developmental approach. It may also suggest ways of working that are consistent with educational (human capital) approaches to development in emerging economies

Identifying and measuring capabilities for career development in NEET young people

Amartya Sen's Capability Approach offers great potential as a conceptual framework for promoting social justice and well-being through economic and educational engagement. Yet the capability approach presents researchers with formidable difficulties, not least because it is intentionally left incomplete, and little guidance is available on its application. It is therefore necessary to make choices in order to apply the approach to a specific context. This paper will introduce the issue of social justice in a career development context, and meth-odological challenges in researching capabilities. It will attempt to provide a rationale for methodological choices in four stages. Firstly, the choice of epis-temology and ontology ; secondly, choices of level of analysis and disciplinary perspective ; thirdly, the choice of research methods. An example of career development with disadvantaged NEET young people (not in employment, education or training) in the United Kingdom will be considered

Bhaskar and Sen: Two foundations on which to build a new approach to career guidance and life planning

This paper argues for a new perspective on guidance and life planning that is informed, but not dominated, by pre-existing Western conceptions of career. Two scholars are highlighted as providing potential foundations for a new approach. Firstly, the critical realism of Roy Bhaskar provides a challenge to the dominant paradigms underpinning the social sciences. Secondly, the capability approach of Amartya Sen provides an alternative to individualistic notions of employability and career management. Whilst the work of Bhaskar and Sen is very different, there are some commonalities. Both are pragmatic, concerned with justice, and allow considerable freedom in the application of their ideas to specific contexts. They have potential for stimulating new approaches to career development pertinent to the needs of rapidly developing economies

The casualties of transition: the health impact of NEET status and some approaches to managing it

Youth unemployment can be understood as a major public health risk. This paper explores the multidisciplinary literature in this field, and its relevance to support for NEET (not in education, employment or training) young people. There is reason to believe that unemployment may have a scarring effect on future labour market prospects and on health, with lifelong consequences for individuals and for society. To the extent that illness has social causation, it may potentially have social remedies. Evidence for the effectiveness of mental health prevention with young people is limited, but there is persuasive recent research suggesting that moving people on from unemployment leads to health improvements. Schools, colleges, vocational training providers, and the welfare benefits system all have a role to play in reducing the impact of unemployment. Career guidance services are particularly well placed to reach potentially vulnerable young people both before and after leaving school, to provide support, and to enable them to access opportunities

The well-being outcomes of career guidance

The potential for career guidance to impact on well-being has received insufficient attention in the UK. There are both conceptual and empirical reasons to expect that the impacts may be positive, but a lack of evidence directly testing this proposition. Career guidance has commonalities with therapeutic counsellingsuggesting analogous effects, and it promotes positive engagement in work and learning, which may be associated with health benefits. There are implications for services in reconciling health and employment objectives. However, the promotion of well-being need not imply quasi-clinical ways of working. A call is made for more research and debate in the career guidance community as to the extent and implications of the potentially important relationship between career guidance and well-being