Natural language processing as a foundation of the semantic Web

The main argument of this paper is that Natural Language Processing (NLP) does, and will continue to, underlie the Semantic Web (SW), including its initial construction from unstructured sources like the World Wide Web (WWW), whether its advocates realise this or not. Chiefly, we argue, such NLP activity is the only way up to a defensible notion of meaning at conceptual levels (in the original SW diagram) based on lower level empirical computations over usage. Our aim is definitely not to claim logic-bad, NLP-good in any simple-minded way, but to argue that the SW will be a fascinating interaction of these two methodologies, again like the WWW (which has been basically a field for statistical NLP research) but with deeper content. Only NLP technologies (and chiefly information extraction) will be able to provide the requisite RDF knowledge stores for the SW from existing unstructured text databases in the WWW, and in the vast quantities needed. There is no alternative at this point, since a wholly or mostly hand-crafted SW is also unthinkable, as is a SW built from scratch and without reference to the WWW. We also assume that, whatever the limitations on current SW representational power we have drawn attention to here, the SW will continue to grow in a distributed manner so as to serve the needs of scientists, even if it is not perfect. The WWW has already shown how an imperfect artefact can become indispensable.

Patients and doctors working together in partnership:Birch v UCL Hospital NHS Foundation Trust [2008] EWHC 2237 (QB)

Of the myriad of pressing topics current in medical law and ethics, the issue of informed consent appears to be the ‘plainer sibling’. The decision by Cranston J in Birch v UCL Hospital NHS Foundation Trust in 2008 has brought into sharp relief that which many commentators already held to be true. Far from being the ‘plainer sibling’ when weighed against other prominent issues in medical law and ethics, the doctrine of informed consent, is one of the most significant principles to emerge in recent years.

Introduction to the theory and application of data envelopment analysis:a foundation text with integrated software

The book aims to introduce the reader to DEA in the most accessible manner possible. It is specifically aimed at those who have had no prior exposure to DEA and wish to learn its essentials, how it works, its key uses, and the mechanics of using it. The latter will include using DEA software. Students on degree or training courses will find the book especially helpful. The same is true of practitioners engaging in comparative efficiency assessments and performance management within their organisation. Examples are used throughout the book to help the reader consolidate the concepts covered. Table of content: List of Tables. List of Figures. Preface. Abbreviations. 1. Introduction to Performance Measurement. 2. Definitions of Efficiency and Related Measures. 3. Data Envelopment Analysis Under Constant Returns to Scale: Basic Principles. 4. Data Envelopment Analysis under Constant Returns to Scale: General Models. 5. Using Data Envelopment Analysis in Practice. 6. Data Envelopment Analysis under Variable Returns to Scale. 7. Assessing Policy Effectiveness and Productivity Change Using DEA. 8. Incorporating Value Judgements in DEA Assessments. 9. Extensions to Basic DEA Models. 10. A Limited User Guide for Warwick DEA Software. Author Index. Topic Index. References.

Nonlinearity in all-night sleep EEG recorded with foramen ovale electrodes in a patient with temporal lobe epilepsy

Objective: It is investigated to which extent measures of nonlinearity derived from surrogate data analysis are capable to quantify the changes of epileptic activity related to varying vigilance levels. Methods: Surface and intracranial EEG from foramen ovale (FO-)electrodes was recorded from a patient with temporal lobe epilepsy under presurgical evaluation over one night. Different measures of nonlinearity were estimated for non-overlapping 30-s segments for selected channels from surface and intracranial EEG. Additionally spectral measures were calculated. Sleep stages were scored according to Rechtschaffen/Kales and epileptic transients were counted and classified by visual inspection. Results: In the intracranial recordings stronger nonlinearity was found ipsilateral to the epileptogenic focus, more pronounced in NREM sleep, weaker in REM sleep. The dynamics within the NREM episodes varied with the different nonlinearity measures. Some nonlinearity measures showed variations with the sleep cycle also in the intracranial recordings contralateral to the epileptic focus and in the surface EEG. It is shown that the nonlinearity is correlated with short-term fluctuations of the delta power. The higher frequency of occurrence of clinical relevant epileptic spikes in the first NREM episode was not clearly reflected in the nonlinearity measures. Conclusions: It was confirmed that epileptic activity renders the EEG nonlinear. However, it was shown that the sleep dynamics itself also effects the nonlinearity measures. Therefore, at the present stage it is not possible to establish a unique connection between the studied nonlinearity measures and specific types of epileptic activity in sleep EEG recordings.

Widening access to Higher Education:an evaluative case study of a foundation year alternative to access

Universities are encouraged to widen access to a broad range of applicants, including mature students taking Access qualifications. Admissions tutors can find it difficult to compare and choose between Access and A-level applications, and Access applicants for popular courses may be disadvantaged relative to students with good A-levels. In this evaluative case study a foundation year designed to avoid Access selection problems and widen participation in psychology, biology, optometry and pharmacy is reviewed. Progression and success rates are compared to national averages for Access courses and issues in Foundation Year management considered. The Foundation Year is rejected as unsatisfactory and it is concluded that widening participation for mature students can be achieved through Access courses. Difficulties in achieving this for high-demand courses in leading universities are discussed.

Mechanisms of altered cortical excitability in photosensitive epilepsy

Despite the multiplicity of approaches and techniques so far applied for identifying the pathophysiological mechanisms of photosensitive epilepsy, a generally agreed explanation of the phenomenon is still lacking. The present thesis reports on three interlinked original experimental studies conducted to explore the neurophysiological correlates and the phatophysiological mechanism of photosensitive epilepsy. In the first study I assessed the role of the habituation of the Visual Evoked Response test as a possible biomarker of epileptic visual sensitivity. The two subsequent studies were designed to address specific research questions emerging from the results of the first study. The findings of the three intertwined studies performed provide experimental evidence that photosensitivity is associated with changes in a number of electrophysiological measures suggestive of altered balance between excitatory and inhibitory cortical processes. Although a strong clinical association does exist between specific epileptic syndromes and visual sensitivity, results from this research indicate that photosensitivity trait seems to be the expression of specific pathophysiological mechanisms quite distinct from the “epileptic” phenotype. The habituation of Pattern Reversal Visual Evoked Potential (PR-VEP) appears as a reliable candidate endo-phenotype of visual sensitivity. Interpreting the findings of this study in the context of the broader literature on visual habituation we can hypothesise the existence of a shared neurophysiological background between photosensitive epilepsy and migraine. Future studies to elucidate the relationship between the proposed indices of cortical excitability and specific polymorphisms of excitatroy and inhibitory neurotransmission will need to be conducted to assess their potential role as biomarkers of photosensitivity.

The effectiveness of lamotrigine in the treatment of photosensitive epilepsy

Photosensitive epilepsy and associated pattern sensitivity are more prevalent in females and are usually treated with sodium valproate. Sodium valproate has an adverse effect profile, which particularly affects females, including teratogenicity, association with the polycystic ovary syndrome and weight gain. It would be useful therefore if an alternative treatment for photosensitive epilepsy could be found. The principle aim of this study was to investigate the effectiveness of lamotrigine in the treatment of photosensitive epilepsy in adults and children. Patients were either drug-naive, commencing lamotrigine therapy or were transferring from other antiepileptic drugs to lamotrigine (primarily sodium valproate) due to lack of response, adverse effects or desired pregnancy. The photoparoxsymal response in the electroencephalograph was used as the primary measure of photo and pattern sensitivity. In addition the effects of lamotrigine on occipital spikes and normal responses in the EEG to visual stimuli were investigated. Secondary measures also included the resting EEG, seizures, body mass index, menstrual function, mood and cognitive function. The results suggest that in adult patients lamotrigine is efficacious in the treatment of photosensitive epilepsy, although it appears inferior to sodium valproate. Lamotrigine does however have a more favourable adverse effect profile than valproate. The results indicate that lamotrigine therapy is suitable for photosensitive epilepsy in women of childbearing age or in patients experiencing unacceptable adverse effects with valproate therapy. Patients are more likely to respond to lamotrigine treatment if they present with sensitivity to a limited number of frequencies. Lamotrigine does not seem to be as efficacious in the treatment of children, although against it may be considered a second line drug if the child does not respond to or will not tolerate sodium valproate.

The strength of column-to-foundation joints in reinforced concrete

This thesis is concerned with the experimental and theoretical investigation into the compression bond of column longitudinal reinforcement in the transference of axial load from a reinforced concrete column to a base. Experimental work includes twelve tests with square twisted bars and twenty four tests with ribbed bars. The effects of bar size, anchorage length in the base, plan area of the base, provision of bae tensile reinforcement, links around the column bars in the base, plan area of column and concrete compressive strength were investigated in the tests. The tests indicated that the strength of the compression anchorage of deformed reinforcing steel in the concrete was primarily dependent on the concrete strength and the resistance to bursting, which may be available within the anchorage . It was shown in the tests without concreted columns that due to a large containment over the bars in the foundation, failure occurred due to the breakdown of bond followed by the slip of the column bars along the anchorage length. The experimental work showed that the bar size , the stress in the bar, the anchorage length, provision of the transverse steel and the concrete compressive strength significantly affect the bond stress at failure. The ultimate bond stress decreases as the anchorage length is increased, while the ultimate bond stress increases with increasing each of the remainder parameters. Tests with concreted columns also indicated that a section of the column contributed to the bond length in the foundation by acting as an extra anchorage length. The theoretical work is based on the Mindlin equation( 3), an analytical method used in conjunction with finite difference calculus. The theory is used to plot the distribution of bond stress in the elastic and the elastic-plastic stage of behaviour. The theory is also used to plot the load-vertical displacement relationship of the column bars in the anchorage length, and also to determine the theoretical failure load of foundation. The theoretical solutions are in good agreement with the experimental results and the distribution of bond stress is shown to be significantly influenced by the bar stiffness factor K. A comparison of the experimental results with the current codes shows that the bond stresses currently used are low and in particular, CPIlO(56) specifies very conservative design bond stresses .

The role of the cortical occipital spike in photosensitive epilepsy

Chapters one to three are an introduction to photosensitive epilepsy, electroencephalography (EEG) and the magnocellular and parvocellular visual pathways. Photoparoxysmal response (PPR) are strongly associated with photosensitive epilepsy. Chapters four to nine investigated whether occipital spikes were associated with PPR and hence with photosensitive epilepsy. The chapters investigated whether the response types showed similar dependence on stimulus characteristics using EEG. Chapters four and five found that occipital spikes and PPR showed different dependence on colour and luminance contrast. The differences were consistent with the magnocellular pathway mediating occipital spikes and the pavocellular pathway mediating PPR. The study in chapter eight found that monocular occlusion had a significantly greater effect on PPR than on occipital spikes, which is further evidence against an association between the two types of response. Chapters six and seven showed that occipital spikes and PPR had similar optimum spatial and temporal frequencies. Chapter nine showed that both response types could be generated via stimulation of the periphery of the retina. However, these three chapters are not strong evidence of an association, as the results do not contradict the theory that the responses are generated via different pathways. The magnocellular and pavocellular pathways have similar optimum temporal and spatial frequencies and both are present in the periphery. In chapter ten, magnetoencephalography was used to estimate the source of activity underlying the components of the VEP and occipital spike. Changes in the amplitude and latency in the components of the normal VEP are associated with epilepsy. However, the source underlying the occipital spikes was not related to that underlying the components of the VEP so this is also removed as a source of evidence for an association between occipital spikes and photosensitive epilepsy.

Ambulatory EEG monitoring in the diagnosis and treatment of epilepsy and related disorders

Ambulatory EEG recording enables patients with epilepsy and related disorders to be monitored in an unrestricted environment for prolonged periods. Attacks can therefore be recorded and EEG changes at the time can aid diagnosis. The relevant Iiterature is reviewed and a study made of' 250 clinical investigations. A study was also made of the artefacts,encountered during ambulatory recording. Three quarters of referrals were for distinguishing between epileptic and non-epileptic attacks. Over 60% of patients showed no abnormality during attacks. In comparison with the basic EEG the ambulatory EEG provided about ten times as much information. A preliminary follow-up study showed that results, of ambulatory monitoring agreed with the final diagnosis in 8 of 12 patients studied. Of 10 patients referred, for monitoring the occurrence of absence seizures, 8 showed abnormality during the baslcJ EEG .and 10 during the ambulatory EEG. Other patients. were referred: for sleep recording and to clarify the seizure type. An investigation into once daily (OD) versus twice daily administration of sodium valproate in patients with absence seizures showed that an OD regime was equally as effective as a BD regime. Circadian variations in spike and wave activity in patients on and off treatment were also examined. There was significant agreement between subjects on the time of occurrence of abnormality during sleep only, This pattern was not ,affected with treatment nor was there any difference in the daily pattern of occurrence of abnormality between the two regimes. Overall findings suggested that ambulatory monitoring was a valuable tool in the diagnosis and treatment of epilepsy which with careful planning and patient selection could be used in any EEG department and would benefit a:wide range of patients.

Abnormal visual habituation in pediatric photosensitive epilepsy

Objective - To investigate visual habituation – a measure of visual cortical excitability – in photosensitive patients in pediatric age and compare the findings with a matched sample with idiopathic generalized epilepsies without photosensitivity and with normally developing children. Methods - We presented a full-field black-and-white checkerboard pattern, at 3 reversal/s with 100% contrast binocularly for 600 consecutive trials and measured the N75–P100 and P100–N145 pattern-reversal visual evoked potential inter-peak amplitudes and N75, P100, N145 latencies for the six blocks of 100 responses. As a measure of habituation we used the slope of the linear regression line of the N75–P100 and P100–N145 peak-to-peak amplitudes. The slope of the linear regression line of the N75–P100 and P100–N145 latencies was also analyzed. Results - Statistical analysis revealed significant differences between the three groups in the slope index of N75–P100 PR-VEP amplitude, with increased or constant amplitude in the PS group compare to the IGE and ND across the six blocks. Conclusions - Our results support the notion that photosensitivity is associated with altered control of excitatory and inhibitory cortical processes. The causal relationship between habituation deficit and photo-paroxysmal response needs to be further investigated with longitudinal studies. Significance This study supports the hypothesis that suppression of PR-VEP is a sensitive intermediate phenotype, which discriminates patients with photosensitivity from those with generalized epilepsies in pediatric age.