Determining feature relevance for the grouping of motor unit action potentials through generative topographic mapping

The study of motor unit action potential (MUAP) activity from electrornyographic signals is an important stage on neurological investigations that aim to understand the state of the neuromuscular system. In this context, the identification and clustering of MUAPs that exhibit common characteristics, and the assessment of which data features are most relevant for the definition of such cluster structure are central issues. In this paper, we propose the application of an unsupervised Feature Relevance Determination (FRD) method to the analysis of experimental MUAPs obtained from healthy human subjects. In contrast to approaches that require the knowledge of a priori information from the data, this FRD method is embedded on a constrained mixture model, known as Generative Topographic Mapping, which simultaneously performs clustering and visualization of MUAPs. The experimental results of the analysis of a data set consisting of MUAPs measured from the surface of the First Dorsal Interosseous, a hand muscle, indicate that the MUAP features corresponding to the hyperpolarization period in the physisiological process of generation of muscle fibre action potentials are consistently estimated as the most relevant and, therefore, as those that should be paid preferential attention for the interpretation of the MUAP groupings.

Generative topographic mapping applied to clustering and visualization of motor unit action potentials

The identification and visualization of clusters formed by motor unit action potentials (MUAPs) is an essential step in investigations seeking to explain the control of the neuromuscular system. This work introduces the generative topographic mapping (GTM), a novel machine learning tool, for clustering of MUAPs, and also it extends the GTM technique to provide a way of visualizing MUAPs. The performance of GTM was compared to that of three other clustering methods: the self-organizing map (SOM), a Gaussian mixture model (GMM), and the neural-gas network (NGN). The results, based on the study of experimental MUAPs, showed that the rate of success of both GTM and SOM outperformed that of GMM and NGN, and also that GTM may in practice be used as a principled alternative to the SOM in the study of MUAPs. A visualization tool, which we called GTM grid, was devised for visualization of MUAPs lying in a high-dimensional space. The visualization provided by the GTM grid was compared to that obtained from principal component analysis (PCA). (c) 2005 Elsevier Ireland Ltd. All rights reserved.

Emotion processing in infancy: specificity in risk for social anxiety and associations with two year outcomes

The current study examined the specificity of patterns of responding to high and low intensity negative emotional expressions of infants of mothers with social phobia, and their association with child outcomes at two years of age. Infants of mothers with social phobia, generalised anxiety disorder (GAD) or no history of anxiety were shown pairs of angry and fearful emotional expressions at 10 weeks of age. Symptoms of social withdrawal, anxiety and sleep problems were assessed at two years of age. Only infants of mothers with social phobia showed a tendency to look away from high intensity fear faces; however infants of mothers with both social phobia and GAD showed a bias towards high intensity angry faces. Among the offspring of mothers with social phobia, anxiety symptoms at two years of age were associated with a preference for high intensity fear faces in infancy. The reverse pattern was found amongst the offspring of non-anxious mothers. These findings suggest a possible specific response to emotional expressions among the children of mothers with social phobia.

CPD records for revalidation: assessing fitness-to-practise using ‘revalidation standards’ and an Outcomes Framework

Background: Currently, all pharmacists and technicians registered with the Royal Pharmaceutical Society of Great Britain must complete a minimum of nine Continuing Professional Development (CPD) record (entries) each year. From September 2010 a new regulatory body, the General Pharmaceutical Council, will oversee the regulation (including revalidation) of all pharmacy registrants in Great Britain. CPD may provide part of the supporting evidence that a practitioner submits to the regulator as part of the revalidation process. Gaps in knowledge necessitated further research to examine the usefulness of CPD in a pharmacy revalidation Project aims: The overall aims of this project were to summarise pharmacy professionals’ past involvement in CPD, examine the usability of current CPD entries for the purpose of revalidation, and to examine the impact of ‘revalidation standards’ and a bespoke Outcomes Framework on the conduct and construction of CPD entries for future revalidation of pharmacy professionals. We completed a comprehensive review of the literature, devised, validated and tested the impact of a new CPD Outcomes Framework and related training material in an empirical investigation involving volunteer pharmacy professionals and also spoke with our participants to bring meaning and understanding to the process of CPD conduct and recording and to gain feedback on the study itself. Key findings: The comprehensive literature review identified perceived barriers to CPD and resulted in recommendations that could potentially rectify pharmacy professionals’ perceptions and facilitate participation in CPD. The CPD Outcomes Framework can be used to score CPD entries Compared to a control (CPD and ‘revalidation standards’ only), we found that training participants to apply the CPD Outcomes Framework resulted in entries that scored significantly higher in the context of a quantitative method of CPD assessment. Feedback from participants who had received the CPD Outcomes Framework was positive and a number of useful suggestions were made about improvements to the Framework and related training. Entries scored higher because participants had consciously applied concepts linked to the CPD Outcomes Framework whereas entries scored low where participants had been unable to apply the concepts of the Framework for a variety of reasons including limitations posed by the ‘Plan & Record’ template. Feedback about the nature of the ‘revalidation standards’ and their application to CPD was not positive and participants had not in the main sought to apply the standards to their CPD entries – but those in the intervention group were more likely to have referred to the revalidation standards for their CPD. As assessors, we too found the process of selecting and assigning ‘revalidation standards’ to individual CPD entries burdensome and somewhat unspecific. We believe that addressing the perceived barriers and drawing on the facilitators will help deal with the apparent lack of engagement with the revalidation standards and have been able to make a set of relevant recommendations. We devised a model to explain and tell the story of CPD behaviour. Based on the concepts of purpose, action and results, the model centres on explaining two types of CPD behaviour, one following the traditional CE pathway and the other a more genuine CPD pathway. Entries which scored higher when we applied the CPD Outcomes Framework were more likely to follow the CPD pathway in the model above. Significant to our finding is that while participants following both models of practice took part in this study, the CPD Outcomes Framework was able to change people’s CPD behaviour to make it more inline with the CPD pathway. The CPD Outcomes Framework in defining the CPD criteria, the training pack in teaching the basis and use of the Framework and the process of assessment in using the CPD Outcomes Framework, would have interacted to improve participants’ CPD through a collective process. Participants were keen to receive a curriculum against which certainly CE-type activities could be conducted and another important observation relates to whether CE has any role to play in pharmacy professionals’ revalidation. We would recommend that the CPD Outcomes Framework is used in the revalidation of pharmacy professionals in the future provided the requirement to submit 9 CPD entries per annum is re-examined and expressed more clearly in relation to what specifically participants are being asked to submit – i.e. the ratio of CE to CPD entries. We can foresee a benefit in setting more regular intervals which would act as deadlines for CPD submission in the future. On the whole, there is value in using CPD for the purpose of pharmacy professionals’ revalidation in the future.

Online customer experience in e-retailing: an empirical model of antecedents and outcomes

The theoretical understanding of online shopping behavior has received much attention. Less focus has been given to the formation of the customer experience (CE) that results from online shopper interactions with e-retailers. This study develops and empirically tests a model of the relationship between antecedents and outcomes of online customer experience (OCE) within Internet shopping websites using an international sample. The study identifies and provides operational measures of these variables plus the cognitive and affective components of OCE. The paper makes contributions towards new knowledge and understanding of how e-

Breathable roofing membranes and bats: interactions, outcomes and predictions

In order to achieve sustainability it is necessary to balance the interactions between the built and natural environment. Biodiversity plays an important part towards sustainability within the built environment, especially as the construction industry comes under increasing pressure to take ecological concerns into account. Bats constitute an important component of urban biodiversity and several species are now highly dependent on buildings, making them particularly vulnerable to anthropogenic and environmental changes. As many buildings suitable for use as bat roosts age, they often require re-roofing and traditional bituminous roofing felts are frequently being replaced with breathable roofing membranes (BRMs), which are designed to reduce condensation. Whilst the current position of bats is better in many respects than 30 years ago, new building regulations and modern materials, may substantially reduce the viability of existing roosts. At the same time building regulations require that materials be fit for purpose and with anecdotal evidence that both bats and BRMs may experience problems when the two interact, it is important to know what roost characteristics are essential for house dwelling bats and how these and BRMs may be affected. This paper reviews current literature and knowledge and considers the possible ways in which bats and BRMs may interact, how this could affect existing bat roosts within buildings and the implications for BRM service life predictions and warranties. It concludes that in order for the construction and conservation sectors to work together in solving this issue, a set of clear guidelines should be developed for use on a national level.