Unveiling the nature of bright z ~ 7 galaxies with the Hubble Space Telescope

We present new Hubble Space Telescope/Wide Field Camera 3 imaging of 25 extremely luminous (-23.2 < M_ UV < -21.2) Lyman-break galaxies (LBGs) at z ~ 7. The sample was initially selected from 1.65 deg^2 of ground-based imaging in the UltraVISTA/COSMOS and UDS/SXDS fields, and includes the extreme Lyman-alpha emitters, `Himiko' and `CR7'. A deconfusion analysis of the deep Spitzer photometry available suggests that these galaxies exhibit strong rest-frame optical nebular emission lines (EW_0(H_beta + [OIII]) > 600A). We find that irregular, multiple-component morphologies suggestive of clumpy or merging systems are common (f_multi > 0.4) in bright z ~ 7 galaxies, and ubiquitous at the very bright end (M_UV < -22.5). The galaxies have half-light radii in the range r_1/2 ~ 0.5-3 kpc. The size measurements provide the first determination of the size-luminosity relation at z ~ 7 that extends to M_UV ~ -23. We find the relation to be steep with r_1/2 ~ L^1/2. Excluding clumpy, multi-component galaxies however, we find a shallower relation that implies an increased star-formation rate surface density in bright LBGs. Using the new, independent, HST/WFC3 data we confirm that the rest-frame UV luminosity function at z ~ 7 favours a power-law decline at the bright-end, compared to an exponential Schechter function drop-off. Finally, these results have important implications for the Euclid mission, which we predict will detect > 1000 similarly bright galaxies at z ~ 7. Our new HST imaging suggests that the vast majority of these galaxies will be spatially resolved by Euclid, mitigating concerns over dwarf star contamination.Comment: 26 pages, 11 figures and 5 tables. Updated to match MNRAS accepted versio

Geometrically derived difference formulae for the numerical integration of trajectory problems

The term 'trajectory problem' is taken to include problems that can arise, for instance, in connection with contour plotting, or in the application of continuation methods, or during phase-plane analysis. Geometrical techniques are used to construct difference methods for these problems to produce in turn explicit and implicit circularly exact formulae. Based on these formulae, a predictor-corrector method is derived which, when compared with a closely related standard method, shows improved performance. It is found that this latter method produces spurious limit cycles, and this behavior is partly analyzed. Finally, a simple variable-step algorithm is constructed and tested

A feasibility study: Forest Fire Advanced System Technology (FFAST)

The National Aeronautics and Space Administration/Jet Propulsion Laboratory and the United States Department of Agriculture Forest Service completed a feasibility study that examined the potential uses of advanced technology in forest fires mapping and detection. The current and future (1990's) information needs in forest fire management were determined through interviews. Analysis shows that integrated information gathering and processing is needed. The emerging technologies that were surveyed and identified as possible candidates for use in an end to end system include ""push broom'' sensor arrays, automatic georeferencing, satellite communication links, near real or real time image processing, and data integration. Matching the user requirements and the technologies yielded a ""strawman'' system configuration. The feasibility study recommends and outlines the implementation of the next phase for this project, a two year, conceptual design phase to define a system that warrants continued development

An exploration into the client at the heart of therapy : a qualitative perspective

Over 50 years ago Eysenck challenged the existing base of research into psychotherapy. Since that time, a large number of investigations have been conducted to verify the efficacy of therapy. Recently however, an increasing number of studies have cast new doubts on this research base. Instead of therapy being a function of the therapist, it is now becoming ever more apparent that the client plays a prime role in the therapeutic process. The qualitative studies presented in this paper provide some examples of research that demonstrates that clients are actively involved in their therapy, even making counselling work despite their counsellor. These studies suggest that clients may not experience therapy as beneficially as traditional outcome studies indicate. This raises a new challenge to researchers to more fully explore the client's experience of therapy, a challenge to which qualitative methods of inquiry would appear well suited

Accelerating Positive Change In Electronic Recrds Management - An Emprical Toolkit Of Solutions

The AC+erm project aims to investigate and critically explore issues and practical strategies for accelerating positive change in electronic records management. The project’s focus is on designing an organisational-centred architecture from three perspectives: people, process and technology. This paper introduces the project, describes the methodology (a systematic literature review, e-Delphi studies and colloquia) and presents solutions for improving ERM developed from the people and process e-Delphi responses. ERM is particularly challenging and the solutions offered by the Delphi participants are numerous, and range in scale and complexity. The only firm conclusion that one can draw is that the majority of the solutions are people-focussed ones. The Cynefin framework is introduced as one approach for providing a conceptual overview to our findings on ERM. The sample solutions presented in this paper provide a toolkit of ‘probes’ and ‘interventions’ for practical application in organisations

The development of the forms of responding to self-critical thoughts Scale (FoReST)

Background: Self-critical thoughts are a feature of many mental health problems. Adopting a psychologically flexible response to thoughts has been highlighted as a key determinant of wellbeing. But, the measurement of psychological flexibility (PF) in relation to self-critical thoughts is under-developed. This paper reports on the development of the Forms of Responding to Self-Critical Thoughts Scale (FoReST). Method: Study One involved the development and exploratory factor analysis of the FoReST in a convenience sample of 253 non-clinical adults. Study Two was a confirmatory factor analysis study of the FoReST in a sample of 110 University students. Study 3 explored the convergent and concurrent validity of the FoReST by examining associations with measures of similar constructs (PF, self-compassion, self-criticism) and relevant mental health measures (anxiety, depression, distress). Study 3 also explored the FoReST’s incremental validity for predicting depression and anxiety levels beyond an established measure of self-critical thinking. Results: In Study One, exploratory factor analysis produced a 9-item/2-factor solution (unworkable action and mindful acceptance). The measure demonstrated good internal consistency. In Study 2, the confirmatory factor analysis also indicated a 2-factor model (unworkable action and mindful acceptance) and overall internal consistency that was excellent. In Study Three, the FoReST demonstrated high convergent validity with similar measures, and good concurrent validity with mental health outcomes. Analyses also indicated good incremental validity for the FoReST for predicting HADS depression and anxiety scores. Conclusions: The FoReST appears to be a psychometrically sound measure suitable for measuring change processes in third wave therapies such as Acceptance and Commitment Therapy, Mindfulness-based Interventions and Compassion Focused therapy

Approximated maximum likelihood estimation in multifractal random walks

We present an approximated maximum likelihood method for the multifractal random walk processes of [E. Bacry et al., Phys. Rev. E 64, 026103 (2001)]. The likelihood is computed using a Laplace approximation and a truncation in the dependency structure for the latent volatility. The procedure is implemented as a package in the R computer language. Its performance is tested on synthetic data and compared to an inference approach based on the generalized method of moments. The method is applied to estimate parameters for various financial stock indices.Comment: 8 pages, 3 figures, 2 table

Migration and multiple sclerosis in immigrants to Australia from United Kingdom and Ireland: a reassessment. I. Risk of MS by age at immigration

A previous study of the prevalence of multiple sclerosis (MS) in 1981 among immigrants from the United Kingdom and Ireland to Australia found that the prevalence for those with age at immigration (AAI) under 15 years of age did not differ from the older immigrants. We have reanalysed the original materials as well as census data for 1901–1981 for UKI and other high MS risk country immigrants. There was a highly significant trend in the prevalence rates of all Australians from New South Wales (NSW) to South Australia (SA) to Western Australia (WA) to Queensland (QLD). Rates by state among the Australian-born were almost identical to these, but there was no prevalence gradient for the UKI-born. The denominator population at risk of MS by AAI was calculated from special census tables of length of residence in Australia by age 0–79 in 1981 for UKI immigrants 1947–1981. The numerator was limited to the subset of 258 MS (Group II) also immigrating in 1947 and later, and age 0–79 in 1981. The absolute risk of MS for these migrants to the four states entering at age 0–14 was 22/100,000, significantly less than for all older age groups; age 15–39 immigrants had a risk of 54/100,000. Similar risk ratios for 0–14 versus 15–39 by state were 31 versus 61 (NSW), 29 versus 44 (QLD), 11 versus 50 (SA), 15 versus 51 (WA)