Sure Start Widnes Children’s Centres: An evaluation of a new programme

This project reports evaluates the publicity material created and used by Sure Start Widnes Children's Centres

Gradient-based quantitative image reconstruction in ultrasound-modulated optical tomography: first harmonic measurement type in a linearised diffusion formulation

Ultrasound-modulated optical tomography is an emerging biomedical imaging modality which uses the spatially localised acoustically-driven modulation of coherent light as a probe of the structure and optical properties of biological tissues. In this work we begin by providing an overview of forward modelling methods, before deriving a linearised diffusion-style model which calculates the first-harmonic modulated flux measured on the boundary of a given domain. We derive and examine the correlation measurement density functions of the model which describe the sensitivity of the modality to perturbations in the optical parameters of interest. Finally, we employ said functions in the development of an adjoint-assisted gradient based image reconstruction method, which ameliorates the computational burden and memory requirements of a traditional Newton-based optimisation approach. We validate our work by performing reconstructions of optical absorption and scattering in two- and three-dimensions using simulated measurements with 1% proportional Gaussian noise, and demonstrate the successful recovery of the parameters to within +/-5% of their true values when the resolution of the ultrasound raster probing the domain is sufficient to delineate perturbing inclusions.Comment: 12 pages, 6 figure

Surrogate Accelerated Bayesian Inversion for the Determination of the Thermal Diffusivity of a Material

Determination of the thermal properties of a material is an important task in many scientific and engineering applications. How a material behaves when subjected to high or fluctuating temperatures can be critical to the safety and longevity of a system's essential components. The laser flash experiment is a well-established technique for indirectly measuring the thermal diffusivity, and hence the thermal conductivity, of a material. In previous works, optimization schemes have been used to find estimates of the thermal conductivity and other quantities of interest which best fit a given model to experimental data. Adopting a Bayesian approach allows for prior beliefs about uncertain model inputs to be conditioned on experimental data to determine a posterior distribution, but probing this distribution using sampling techniques such as Markov chain Monte Carlo methods can be incredibly computationally intensive. This difficulty is especially true for forward models consisting of time-dependent partial differential equations. We pose the problem of determining the thermal conductivity of a material via the laser flash experiment as a Bayesian inverse problem in which the laser intensity is also treated as uncertain. We introduce a parametric surrogate model that takes the form of a stochastic Galerkin finite element approximation, also known as a generalized polynomial chaos expansion, and show how it can be used to sample efficiently from the approximate posterior distribution. This approach gives access not only to the sought-after estimate of the thermal conductivity but also important information about its relationship to the laser intensity, and information for uncertainty quantification. We also investigate the effects of the spatial profile of the laser on the estimated posterior distribution for the thermal conductivity

Exploring the value of the capability approach for vocational education and training evaluation: reflections from South Africa

In the late 1990s, South Africa was faced with the triple challenge of reforming the Apartheid divided institutional landscape of vocational education and training (VET) institutions; addressing equitable access to skills; and reorienting its skills development system to the nation’s insertion into the global economy. A wave of institutional reforms was enacted and a large programme of evaluative research followed in its wake. Whilst this body of work was both valuable and necessary, as significant practitioners in this programme we can see several of its limitations. Thus, we counterpose an alternative approach to evaluation that draws on the insights of the capabilities approach. By putting the needs of people first – rather than the needs of the economy – the capability approach brings to the forefront of VET evaluation the importance of social justice, human rights, and poverty alleviation. Such an approach pays better attention to what individuals and institutions value and are seeking to do, whilst retaining the economic rationale as an important part of such analysis; and insisting on the continued salience of evaluation for the improvement of delivery and outcomes

Advancing life projects: South African students explain why they come to FET colleges

VET policy in South Africa is based on a set of assumptions regarding the identity of learners and why learners are in public further education and training (FET) colleges. These assumptions reflect an international orthodoxy about the centrality of employability that is located within what Giddens (1994) has described as “productivism”, a view that reduces the lifeworld to the economic sphere. Through exploring the stories of a group of South African public FET college learners regarding their reasons for choosing FET colleges, this paper shows that VET is valued by these students for a range of reasons. These include preparation for the world of work, but also a desire to improve their ability to contribute to their communities and their families; raise their self-esteem; and expand their future life possibilities. Thus, the paper advances the largely hitherto theoretical critique of productivist VET accounts by offering empirical evidence of counter-narratives

Making gains: the impact of outdoor residential experiences on students’ examination grades and self-efficacy

In this paper we explore the role of outdoor residential experiences on the sense of efficacy and examination attainment of a group of under achieving students from socially disadvantaged backgrounds. The paper reports on a three year project which focuses on two groups of year nine (age 14) to year eleven (age 16) students. The results reported here strongly suggest that the impact of these visits has been significant in terms of students’ sense of confidence and efficacy and had a statistically significant impact on formal examination results in school. We conclude by suggesting that outdoor residential experiences have real educational value for those that take part and, given the evidence provided, believe this poses an interesting question as to whether the classroom should remain the primary site of learning because of the ways it develops positive outcomes within school

An Investigation into Cultural Events and Tourism on the Isle of Man

This paper investigates the significance of cultural events for the development of tourism on the Isle of Man. Historically the Isle of Man captured tourists from areas around the Irish Sea including England, Wales, Scotland, and Northern Ireland. This was especially the case with working-class tourists from the industrial North of England, North Wales, Dublin and Belfast. These tourism markets were prominent in the late 19th, and early and mid 20th centuries. Recent tourist data shows a fall in visitor numbers to the Isle of Man which has taken effect in post war years. In order to explore this decline, and the significance of cultural events for the development of tourism in recent years, a number of research methods have been deployed involving secondary data to assess tourism development and tourism sector growth determinants. As a consequence an investigation was undertaken involving sequential parts. Part one considered trends in the 19th, 20th and early 21st centuries drawing primarily on secondary data, existing research and archival material. Part two investigated cultural events to provide findings and analysis for the tourism industry on the Island. Lastly, part three assessed the nature and importance of events according to the modern evolution of the sector. External (international) and internal (island) influences on development were considered. From the findings conclusions showing prominent issues from the trends observed have enabled consideration of the importance of cultural events for tourism development

Recombinational DNA Repair in Cancer and Normal Cells: The Challenge of Functional Analysis

A major goal of current cancer research is to understand the functional consequences of mutations in recombinational DNA repair genes. The introduction of artificial recombination substrates into living cells has evolved into a powerful tool to perform functional analysis of DNA double strand break (DSB) repair. Here, we review the principles and practice of current plasmid assays with regard to the two major DSB repair pathways, homologous recombination and nonhomologous end-joining. A spectrum of assay types is available to assess repair in a wide variety of cell lines. However, several technical challenges still need to be overcome. Understanding the alterations of DSB repair in cancers will ultimately provide a rational basis for drug design that may selectively sensitize tumor cells to ionizing radiation and chemotherapy, thereby achieving therapeutic gain

Efficient inversion strategies for estimating optical properties with Monte Carlo radiative transport models

Significance: Indirect imaging problems in biomedical optics generally require repeated evaluation of forward models of radiative transport, for which Monte Carlo is accurate yet computationally costly. We develop an approach to reduce this bottleneck, which has significant implications for quantitative tomographic imaging in a variety of medical and industrial applications.Aim: Our aim is to enable computationally efficient image reconstruction in (hybrid) diffuse optical modalities using stochastic forward models.Approach: Using Monte Carlo, we compute a fully stochastic gradient of an objective function for a given imaging problem. Leveraging techniques from the machine learning community, we then adaptively control the accuracy of this gradient throughout the iterative inversion scheme to substantially reduce computational resources at each step.Results: For example problems of quantitative photoacoustic tomography and ultrasound-modulated optical tomography, we demonstrate that solutions are attainable using a total computational expense that is comparable to (or less than) that which is required for a single high-accuracy forward run of the same Monte Carlo model.Conclusions: This approach demonstrates significant computational savings when approaching the full nonlinear inverse problem of optical property estimation using stochastic methods