A Bayesian Filtering Algorithm for Gaussian Mixture Models

A Bayesian filtering algorithm is developed for a class of state-space systems that can be modelled via Gaussian mixtures. In general, the exact solution to this filtering problem involves an exponential growth in the number of mixture terms and this is handled here by utilising a Gaussian mixture reduction step after both the time and measurement updates. In addition, a square-root implementation of the unified algorithm is presented and this algorithm is profiled on several simulated systems. This includes the state estimation for two non-linear systems that are strictly outside the class considered in this paper

Significant therapy events with clients with intellectual disabilities

© 2018, Emerald Publishing Limited. Purpose: The purpose of this paper is to explore significant events in psychotherapy with clients with intellectual disabilities (IDs). Design/methodology/approach: Four therapy dyads, each consisting of one client and one therapist, were recruited. Following the brief structured recall procedure (Elliott and Shapiro, 1988), semi-structured interviews focused on helpful events in psychotherapy, using video of particular sessions as a stimulus to help prompt recall of that session. Findings: Using interpretative phenomenological analysis, five super-ordinate themes were identified: “The Uniqueness of the Therapeutic Relationship”; “Using adaptations to Express Emotions”; “Client Behaviour/Therapist Behaviour”; “Hope and Paternalism”; and “Meaning-Making”. The results provide additional evidence that significant therapy events occur for clients with IDs. Furthermore, the research enabled insights to be gained about the process of therapy for this client group and for exploration of therapeutic factors that may be involved in facilitating a significant therapy event. Research limitations/implications: This study highlights the need for therapists to work in such a way as to facilitate significant events in therapy. Whilst this study was a necessary first step, owing to the non-existence of research in this area, the sample size and qualitative design may limit any wider generalisation of the findings. Originality/value: Significant events have not previously been explored in psychotherapy with clients with IDs. This research could therefore make an important contribution to our understanding of the process of psychotherapy for this client group

Identifying genetic biomarkers of survival for colorectal cancer

Background Clinical stage is the only routinely used marker of survival from colorectal cancer (CRC). Other factors thought to influence prognosis include the location of the primary tumour and the patient’s germline and the tumour’s somatic genetic profile. Aims of my thesis To examine inherited variation as a determinant of patient outcome with further analyses stratified by primary tumour site and mitogen-activated protein kinase (MAPK) activation status. To consider whether known somatic prognostic mutations might mask novel candidate loci. Materials and Methods I performed a genome-wide association study (GWAS), gene and gene-set analyses for survival in 1,926 patients with advanced CRC from the COIN and COIN-B clinical trials with replication in 5,675 patients from the Study of Colorectal Cancer in Scotland (SOCCS), 16,964 patients from the International Survival Analysis in Colorectal cancer Consortium and 5,078 patients with CRC from the UK Biobank. To understand underlying mechanism(s), I performed expression analyses both by variant and transcriptome-wide, and investigated the relationship between expression in colorectal tumours and survival in patients from The Human Protein Atlas. Results In COIN and COIN-B, the most significant SNP associated with survival was rs79612564 in ERBB4 (hazard ratio [HR]=1.24, 95% confidence interval [CI]=1.16–1.32, P=1.9x10−7) which was replicated in stage-IV patients from SOCCS (P=2.1x10−2); mechanistically, patients with high ERBB4 expression in their colon adenocarcinomas had worse survival (HR=1.50, 95% CI=1.1–1.9, P=4.6x10−2). When stratifying by primary tumour location, rs76011559 replicated in patients with proximal tumours (COIN, COIN-B and UK Biobank combined HR=1.53, 95% CI=1.19-1.86, P=7.5x10-7) and rs12273047 replicated in patients with rectal tumours (HR=1.27, 95% CI=1.09-1.46, P=4.1x10-7). PI4K2B associated with survival in patients with distal cancers (P=2.1x10-6) and increased PI4K2B expression in colorectal tumours was associated with improved survival (P=9.6x10-5). RASAL2, encoding a RAS GTPase-activating protein, was the most significant gene associated with survival in patients with MAPK-activated CRCs (P=2.0x10−5) with further analyses revealing pathway specificity. Finally, rs11062901 in PARP11 was a novel biomarker of survival when unmasked from known somatic prognostic factors (HR=1.99, 95% CI=1.5-2.5, P=4.5x10-8) and supported by gene (P=1.4x10-6) and transcriptome-wide (P=1.1x10-5) analyses. Conclusions My data identify novel loci potentially associated with survival from CRC, together with mechanistic insights, many of which were mediated by changes in gene expression

Towards a sustainable airline business model : addressing the forces impacting on European based airlines

Since the year 2000 the existing business model of many European airlines has come under extreme financial pressure from a weak and volatile economy, the threat of international conflict, terrorism and pandemics, as well as a high dependence on the supply and price of fossil fuels. Oil based transport is becoming a major sustainability issue due to price and supply fluctuations, geopolitics, and burgeoning environmental concerns. This thesis examines the role of business model innovation in supporting a sustainability transition in the European airline sector. To achieve this aim, I develop a novel framework that links the Multi-Level Perspective (MLP), the STOF model and business model innovation to understand the drivers affecting the European airline industry. I adopt a four-stage mixed-method approach consisting of a quantitative study of published European airline results, a grey literature review, forty structured interviews and a final triangulation. The findings pinpoint the failings of the industry and detail the major issues concerning its sustainability transition to a low carbon industry. A fragmentation towards four business model groups is identified. The results of the research indicate that changes to airline business models are reactions to forces arising from the MLP and do not lead industry transition. The study indicates that a long incremental sustainability transition in an internationally regulated industry using evolving complex technologies is difficult to capture by reworking airline business models, but that the adoption of new technology can advance system transition. The separation of these technologies into operating ´parcels´ could offer a valuable understanding of their contribution to the business model construct. A sequenced framework for industry transition is proposed. The thesis contributes to the limited literature on the role of business model innovation in shaping sustainability transitions and highlights critical issues and challenges facing the airline sector in Europe

Mapping the e-Learning Assessment Domain: Concept Maps for Orientation and Navigation

Concept or Topic Maps have long been used as a method of categorizing and organizing information about a domain. Building them can help people conceptualize an area and spot trends or gaps, and as a presentation method they quickly provide an overview and general impression of a space. We are currently constructing a Reference Model of the Assessment Domain that takes the form of a highly interlinked dynamic website. This represents the assessment domain via the software, projects, standards and use cases of which it is composed. In this paper we present our efforts to create complimentary concept maps of the assessment domain, not as an overview, but for navigation and orientation within the domain. These concept maps, which model resources and activities independently, have been corroborated with practitioners in the e-learning community