Optimizing Echo State Networks for Static Pattern Recognition

Static pattern recognition requires a machine to classify an object on the basis of a combination of attributes and is typically performed using machine learning techniques such as support vector machines and multilayer perceptrons. Unusually, in this study, we applied a successful time-series processing neural network architecture, the echo state network (ESN), to a static pattern recognition task. The networks were presented with clamped input data patterns, but in this work, they were allowed to run until their output units delivered a stable set of output activations, in a similar fashion to previous work that focused on the behaviour of ESN reservoir units. Our aim was to see if the short-term memory developed by the reservoir and the clamped inputs could deliver improved overall classification accuracy. The study utilized a challenging, high dimensional, real-world plant species spectroradiometry classification dataset with the objective of accurately detecting one of the world’s top 100 invasive plant species. Surprisingly, the ESNs performed equally well with both unsettled and settled reservoirs. Delivering a classification accuracy of 96.60%, the clamped ESNs outperformed three widely used machine learning techniques, namely support vector machines, extreme learning machines and multilayer perceptrons. Contrary to past work, where inputs were clamped until reservoir stabilization, it was found that it was possible to obtain similar classification accuracy (96.49%) by clamping the input patterns for just two repeats. The chief contribution of this work is that a recurrent architecture can get good classification accuracy, even while the reservoir is still in an unstable state

One hundred ten consecutive primary orthotopic liver transplants under FK 506 in adults.

An account is given of the 6- to 12-month survival, and causes of failure in 110 consecutive patients who underwent primary liver transplantation under treatment from the outset with FK 506 and steroids. The patient survival is 92.7%, and the first graft survival is 87.3%. At a very high frequency, the patients achieved good graft function, and they had a relatively low morbidity that was partially ascribable to minimal use and early discontinuance (in 60% of cases) of steroids. Renal dysfunction and other adverse findings were largely confined to patients with poor initial graft function and consequent apparent alteration of the kinetics of FK 506 elimination, causing functional overdosage. Results compare very favorably with our past record using conventional immunosuppression, and support the belief that FK 506 is a superior immunosuppressive agent which is suitable for chronic administration

A Comparison of Human Neutrophils Acquired from Four Experimental Models of Inflammation

Defects in neutrophil function have been implicated in a wide spectrum of clinical conditions. Several models are employed to study activated human neutrophils akin to those found at a site of inflammation. These include whole blood (WB) ex vivo stimulation with lipopolysaccharide (LPS) and in vivo techniques: cantharidin blister, skin windows and intra-dermal injection of UV-killed E.coli (UVKEc). Neutrophils obtained from these have never been compared. We compared the activation status of neutrophils from each technique in order to inform the optimal model for use in human studies. Healthy male volunteers were randomised to undergo one of the four techniques (n = 5/group). LPS: WB stimulated with 1ng/ml of LPS for 4 hours. Cantharidin: 12.5μl of 0.1% cantharidin elicited a single blister, aspirated at 24 hours. Skin windows: four 6mm mechanical-suction blisters created, de-roofed and an exudate-collection chamber placed over the windows for 4 hours before aspiration. UVKEc: 1.5 x 107 UVKEc injected intra-dermally. A single 10mm mechanical-suction blister formed and aspirated at 4 hours. Unstimulated WB used as the control. Flow cytometry was used to determine activation status using CD16, CD11b, CD54, CD62L and CD88. Functional status was assessed with a phagocytosis assay. The pattern of neutrophil activation was similar in all models. Neutrophil CD11b was elevated in all models, most markedly in UVKEc (p<0.0001), and CD54 was also elevated but only significant in the LPS model (p = 0.001). CD62L was significantly reduced in all 4 models (p<0.0001) and CD88 was also suppressed in all. There were no changes in CD16 in any model, neither was there any significant difference in the phagocytic capacity of the neutrophils. In summary, there are no significant differences in activation marker expression or phagocytic capacity in the neutrophils obtained from each technique. Therefore we believe whole blood stimulation is the best model in experimentally challenging inpatient populations

The effect of fission-energy Xe ion irradiation on the structural integrity and dissolution of the CeO2_2 matrix

© 2016 The Authors.This work considers the effect of fission fragment damage on the structural integrity and dissolution of the CeO₂ matrix in water, as a simulant for the UO₂ matrix of spent nuclear fuel. For this purpose, thin films of CeO₂ on Si substrates were produced and irradiated by 92 MeV 129Xe23+ ions to a fluence of 4.8 × 1015 ions/cm2 to simulate fission damage that occurs within nuclear fuels along with bulk CeO₂ samples. The irradiated and unirradiated samples were characterised and a static batch dissolution experiment was conducted to study the effect of the induced irradiation damage on dissolution of the CeO₂ matrix. Complex restructuring took place in the irradiated films and the irradiated samples showed an increase in the amount of dissolved cerium, as compared to the corresponding unirradiated samples. Secondary phases were also observed on the surface of the irradiated CeO₂ films after the dissolution experiment.The irradiation experiment was performed at the Grand Accélérateur National d’Ions Lourds (GANIL) Caen, France, and supported by the French Network EMIR. The support in planning and execution of the experiment by the CIMAP-CIRIL and the GANIL staff, especially, I. Monnet, C. Grygiel, T. Madi and F. Durantel is much appreciated. Thanks are given to I. Buisman and M. Walker from the Department of Earth Sciences, University of Cambridge for help in conducting electron probe microanalysis and polishing the samples, respectively. A.J. Popel acknowledges funding from the UK EPSRC (grant EP/I036400/1 and EP/L018616/1) and Radioactive Waste Management Ltd (formerly the Radioactive Waste Management Directorate of the UK Nuclear Decommissioning Authority, contract NPO004411A-EPS02)

Challenges of Incorporating Digital Health Technology Outcomes in a Clinical Trial: Experiences from PD STAT.

Digital health technologies (DHTs) have great potential for use as clinical trial outcomes; however, practical issues need to be addressed in order to maximise their benefit. We describe our experience of incorporating two DHTs as secondary/exploratory outcome measures in PD STAT, a randomised clinical trial of simvastatin in people with Parkinson's disease. We found much higher rates of missing data in the DHTs than the traditional outcome measures, in particular due to technical and software difficulties. We discuss methods to address these obstacles in terms of protocol design, workforce training and data management

Fault Detection in Steel-Reinforced Concrete Using Echo State Networks

The cost of maintaining and repairing the world's ageing reinforced concrete infrastructure continues to increase, and is expected to cost the United States economy alone $58 billion by 2020. Consequently, the use of non-destructive testing technologies for the early identification of faults in roads and bridges is becoming increasingly important. One such technology is the Electromagnetic Anomaly Detection (EMAD) technique, which exploits non-destructive magnetic flux leakage to detect defects in steel reinforcing meshes embedded in concrete. Despite the increasing need for such techniques, the data analysis options currently in use are limited. This paper presents an application of Echo State Networks, a recurrent neural network from the field of reservoir computing that features a short-term memory, to data obtained using the EMAD technique. Having been trained to discern real defect signals from other anomalous magnetic features, the performance of the ESNs was then compared to that of an analytical data analysis technique that is currently used to process EMAD data. It was found that average ESN performance was comparable in terms of AUC, while the optimal threshold was more consistent, greatly aiding application in the `real-world'. A qualitative analysis of the output of both methods on an unseen testing dataset also demonstrated the superiority of ESNs for practical use as a real time tool for on-site inspections

Heterogeneous data fusion for the improved non-destructive detection of steel-reinforcement defects using echo state networks

The degradation of roads is an expensive problem: in the UK alone, £27 billion was spent on road repairs between 2013 and 2019. One potential cost-saver is the early, non-destructive detection of faults. There are many available techniques, each with its own benefits and drawbacks. This paper builds upon the successful processing of Magnetic Flux Leakage (MFL) data by Echo State Networks (ESNs) for damage diagnostics, by augmenting ESNs with the depth of concrete cover as part of a data fusion approach. This fusion-based ESN outperformed a number of non fusion ESN comparators and a previously used analytical technique. Additionally, the fusion ESN had an optimal threshold value whose standard deviation was three times smaller than that of the nearest alternative technique, potentially prompting a move towards automated defect detection in ‘real-world’ applications

Hearing from justice-involved, care experienced children: what are their experiences of residential care environments and regimes?

Purpose The disproportionate representation in juvenile justice systems of children who are, or have been, in the care of the state is a major cause of concern internationally. However, the experiences of this particular group are largely absent from both policy debates and the international research base. This paper aims to correct that deficit by exploring the lived experiences of residential care, justice-involved children. Design/methodology/approach An interpretivist investigation of care experienced children’s perceptions of their experiences, involving semi-structured interviews with a purposive sample of 19 children in England who were simultaneously in residential care and subject to youth justice supervision. Data were analysed using thematic content analysis. Findings Care-experienced children described how their experiences of residential care environments and regimes have undermined their sense of how they see themselves, now and looking to the future. Against this background of disrupted identity, they also reported stigmatising interactions with staff that leave them feeling labelled both as a generic “looked-after child” and as a “bad kid”. Research limitations/implications The findings are based on the perceptions of a group of children in the criminal justice system, which, although reflecting the experiences of those with negative outcomes, may not be representative of all children in residential care. Practical implications The findings have implications for those responsible for the care and development of care-experienced children, as well policymakers concerned with reducing the numbers of care-experienced children in youth justice. Those responsible for the care and development of care-experienced children should consider steps to reduce how factors outlined here disrupt a child’s sense of self and introduce criminogenic labelling and stigma. Originality/value Despite a number of studies seeking to understand why the number of care experienced children in the youth justice system is disproportionate, there is very little empirical work that seeks to understand the experiences and perceptions of children currently both in care and the criminal justice system. This paper seeks to correct this deficit, by detailing how children who are both in residential care and subject to youth justice supervision view their care experiences. The implications of this for policy, practice and further research are then explored

Challenges of Incorporating Digital Health Technology Outcomes in a Clinical Trial: Experiences from PD STAT

\ua9 2022 - The authors. Published by IOS Press.Digital health technologies (DHTs) have great potential for use as clinical trial outcomes; however, practical issues need to be addressed in order to maximise their benefit. We describe our experience of incorporating two DHTs as secondary/exploratory outcome measures in PD STAT, a randomised clinical trial of simvastatin in people with Parkinson\u27s disease. We found much higher rates of missing data in the DHTs than the traditional outcome measures, in particular due to technical and software difficulties. We discuss methods to address these obstacles in terms of protocol design, workforce training and data management