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Optimal designs of mean-covariance models for longitudinal data
No full textLongitudinal data analysis has been very common in various fields. It is important in longitudinal studies to choose appropriate numbers of subjects and repeated measurements and allocation of time points as well. Therefore, existing studies proposed many criteria to select the optimal designs. However, most of them focused on the precision of the mean estimation based on some specific models and certain structures of the covariance matrix. In this paper, we focus on both the mean and the marginal covariance matrix. Based on the mean-covariance models, it is shown that the trick of symmetrization can generate better designs under a Bayesian D-optimality criterion over a given prior parameter space. Then, we propose a novel criterion to select the optimal designs. The goal of the proposed criterion is to make the estimates of both the mean vector and the covariance matrix more accurate and the total cost is as low as possible. Further, we develop an algorithm to solve the corresponding optimization problem. Based on the algorithm, the criterion is illustrated by an application to a real data set and some simulation studies. We show the superiority of the symmetric optimal design and the symmetrized optimal design in terms of the relative efficiency and parameter estimation. Moreover, we also demonstrate that the proposed criterion is more effective than the previous criteria and it is suitable for both maximum likelihood estimation and restricted maximum likelihood estimation procedures
Rituximab versus Tocilizumab in anti-TNF inadequate responder patients with Rheumatoid Arthritis (R4RA): a stratified, biopsy-driven, multi-centre, randomised, open label, controlled clinical trial – 16 week outcomes
No full textLiking That It Hurts: The Case of the Masochist and Second-Order Desire Accounts of Pain’s Unpleasantness
No full textRecent work on pain focuses on the question ‘what makes pains unpleasant’. SOD views claim that the unpleasantness of pain consists in a second-order intrinsic desire that the pain experience itself cease or stop. This paper considers a significant objection to SOD views by considering the case of the masochist. It is argued that various ways in which the SOD view might try to account for the case of the masochist encounter problems. The conclusion is that until we have a convincing explanation of how SOD views can handle masochistic psychology, then we should look elsewhere for an account of pains unpleasantness
A Robot that Counts Like a Child:A Developmental Model of Counting and Pointing
No full textIn this paper, a novel neuro-robotics model capable of countingreal items is introduced. The model allows us to investigate the interactionbetween embodiment and numerical cognition. This is composed of a deepneural network capable of image processing and sequential tasks performance,and a robotic platform providing the embodiment - the iCub humanoid robot.The network is trained using images from the robot's cameras and proprioceptive signals from its joints. The trained model is able to count a set ofitems and at the same time points to them. We investigate the inuence of pointing on the counting process and compare our results with those from studies with children. Several training approaches are presented in this paper all of them uses pre-training routine allowing the network to gain the ability of pointing and number recitation (from 1 to 10) prior to counting training. The impact of the counted set size and distance to the objects are investigated. The obtained results on counting performance show similarities with those from human studies
A Set of Batched Basic Linear Algebra Subprograms and LAPACK Routines
No full textThis paper describes a standard API for a set of Batched Basic Linear Algebra Subprograms (Batched BLAS or BBLAS). The focus is on many independent BLAS operations on small matrices that are grouped together and processed by a single routine, called a Batched BLAS routine. The matrices are grouped together in uniformly sized groups, with just one group if all the matrices are of equal size. The aim is to provide more efficient, but portable, implementations of algorithms on high-performance many-core platforms. These include multicore and many-core CPU processors, GPUs and coprocessors, and other hardware accelerators with floating-point compute facility. As well as the standard types of single and double precision, we also include half and quadruple precision in the standard. In particular half precision is used in many very large scale applications, such as those associated with machine learning
Hydrogen and methane breath test results are negatively associated with IBS and may reflect transit time in post-surgical patients.
No full textBackground: Contention surrounds hydrogen and methane breath tests as putative measures of small intestinal bacterial overgrowth. We aimed to explore the clinical characteristics associated with positive and negative results to help clarify their role.Methods: 525 glucose hydrogen/methane breath tests completed over 3 years were analysed to look for positively and negatively associated predictive factors. Characteristics such as height and weight and underlying medical conditions, medications and surgical history were collated. Key results: There were 85 and 42 positive hydrogen and methane tests respectively. Patients with irritable bowel syndrome (IBS) (HR 0.17, p=0.004) and those with a higher Body Mass Index (HR 0.93, p=0.004) were significantly less likely to have a positive test. Patients who underwent the test post-surgically were significantly more likely to have a positive test (HR 2.76, p=0.001). A sub-analysis of post-surgical patients by type and region of surgical resection demonstrated that none were statistically more likely than the next to have a positive test. However, for the surgical group as a whole the number of motility depressing drugs taken (such as opioids) was associated with a significantly decreased likelihood of a positive test (HR 0.752 p=0.045).Conclusion: Our data suggest that patients with a diagnosis of IBS are statistically less likely to have a positive test and it is of limited utility in this group. Post-surgical patients are more likely to have a positive test, possibly secondary to fast transit rather than bacterial overgrowth, as suggested by a significantly negative association with motility suppressing drugs in this sub-group.<br/
Is the NHS Diabetes Prevention Programme intervention delivered as planned? An observational study of fidelity of intervention delivery
No full textBackgroundThe NHS Diabetes Prevention Programme (NHS-DPP) has been delivered by four commercial organisations across England, to prevent people with impaired glucose tolerance developing Type 2 diabetes. Evidence reviews underpinning the NHS-DPP design specification identified 19 Behaviour Change Techniques (BCTs) that are the intervention “active ingredients”. It is important to understand discrepancies between BCTs specified in design and BCTs actually delivered. PurposeTo compare observed fidelity of delivery of BCTs that were delivered to (a) the NHS-DPP design specification, and (b) the programme manuals of four provider organisations.MethodsAudio-recordings were made of complete delivery of NHS-DPP courses at eight diverse sites (two courses per provider organisation). The eight courses consisted of 111 group sessions, with 409 patients and 35 facilitators. BCT Taxonomy v1 was used to reliably code the contents of NHS-DPP design specification documents, programme manuals for each provider organisation, and observed NHS-DPP group sessions.ResultsThe NHS-DPP design specification indicated 19 BCTs that should be delivered, whereas only 7 (37%) were delivered during the programme in all eight courses. By contrast, between 70% and 89% of BCTs specified in programme manuals were delivered. There was substantial under-delivery of BCTs that were designed to improve self-regulation of behaviour, e.g. those involving problem solving and self-monitoring of behaviour.ConclusionsA lack of fidelity in delivery to the underlying evidence base was apparent, due to poor translation of design specification to programme manuals. By contrast, the fidelity of delivery to the programme manuals was relatively good. Future commissioning should focus on ensuring the evidence base is more accurately translated into the programme manual contents.<br/
Supported decision-making and mental capacity assessment in care homes: a qualitative study
No full textUp to 75% of UK care home residents may lack the mental capacity to make certain decisions (Wade, 2019). Care home staff need evidence-based tools to help them assess residents’ mental capacity and provide decision-making support (NICE, 2018). The Mental Capacity Assessment Support Toolkit (MCAST) was designed to support multidisciplinary healthcare staff to prepare, complete and document legally-compliant mental capacity assessments. MCAST has not yet been trialled in care homes. This study used a descriptive qualitative design to: i) understand the current challenges faced by care home staff when supporting residents to make decisions and participate in mental capacity assessments; ii) explore staff members’ support needs in this context; and iii) to identify if and how the toolkit could be adapted for use in care homes. A purposive sample of 29 staff working as managers (n=18), nurses (n=7) and care assistants (n=4) across five care homes in North West England participated in five semi-structured focus groups between May and July 2019. Data from the focus group transcripts were analysed thematically (Braun & Clarke, 2006). Five main themes were identified: i) involvement of residents in decision-making; ii) approaches to mental capacity assessment; iii) working with residents with communication difficulties; iv) feelings about practice; and v) responses to MCAST. Participants appeared competent and confident about supporting decision-making and assessing capacity, but recognised the complexity of this area of practice, and identified a need for further support. They reported a range of challenges, including accessing support from speech and language therapists for residents with communication needs. They responded positively to the toolkit and were keen to use it in practice. This study suggests that care home staff would benefit from, and welcome, support to develop their practice. Furthermore, MCAST appears usable in this context and formal feasibility testing is justified
Cycles of de-internationalization and re-internationalization:Towards an integrative framework
No full textInternationalization is a complex process that is neither always forward moving nor monotonic. Firms often reduce the depth and scope of their international footprint or even completely withdraw from foreign markets. Although scholars have recognized that there are cycles of de-internationalization and re-internationalization (and increasingly pressures for back-shoring), the antecedents and motivators for these internationalization pathways have received limited attention. In this study, we first review prior explanations as to why firm behaviour exhibits cycles of de-internationalization and re-internationalization. We then formulate an integrative framework and propose a comprehensive agenda for future research aimed at advancing internationalization theory.</p