A comparative evaluation of term recognition algorithms

Automatic Term Recognition (ATR) is a fundamental processing step preceding more complex tasks such as semantic search and ontology learning. From a large number of methodologies available in the literature only a few are able to handle both single and multi-word terms. In this paper we present a comparison of five such algorithms and propose a combined approach using a voting mechanism. We evaluated the six approaches using two different corpora and show how the voting algorithm performs best on one corpus (a collection of texts from Wikipedia) and less well using the Genia corpus (a standard life science corpus). This indicates that choice and design of corpus has a major impact on the evaluation of term recognition algorithms. Our experiments also showed that single-word terms can be equally important and occupy a fairly large proportion in certain domains. As a result, algorithms that ignore single-word terms may cause problems to tasks built on top of ATR. Effective ATR systems also need to take into account both the unstructured text and the structured aspects and this means information extraction techniques need to be integrated into the term recognition process.

Political representation in France: a crisis of democracy?

The past two decades have witnessed growing political disaffection and a widening mass/elite disjuncture in France, reflected in opinion polls, rising abstentionism, electoral volatility and fragmentation, with sustained voting against incumbent governments. Though the electoral system has preserved the duopoly of the mainstream coalitions, they have suffered loss of public confidence and swings in electoral support. Stable parliamentary majorities conceal a political landscape of assorted anti-system parties and growing support for far right and far left. The picture is paradoxical: the French express alienation from political parties yet relate positively to their political institutions; they berate national politicians but retain strong bonds with those elected locally; they appear increasingly disengaged from politics yet forms of ‘direct democracy’ are finding new vigour. While the electoral, attitudinal and systemic factors reviewed here may not signal a crisis of democracy, they point to serious problems of political representation in contemporary France.

Patients’ and physicians’ experiences of atrial fibrillation and anticoagulation therapy:a qualitative journey

Background: Oral anticoagulation (OAC) reduces stroke risk in patients with atrial fibrillation (AF) however it is often underutilized and sometimes refused by patients. This programme of work included a meta-synthesis and two inter-linking studies aiming to explore patients’ and physicians’ experiences of AF and OAC. Methods: A meta-synthesis of qualitative evidence was conducted which informed the empirical work. Semi-structured individual interviews were utilised. Study 1: Three AF patient sub-groups were interviewed; accepted (n=4), refused (n=4), or discontinued (n=3) warfarin. Study 2: Four physician sub-groups (n=4 each group) prescribing OAC to AF patients were interviewed: consultant cardiologists, consultant general physicians, general practitioners and cardiology registrars. Data was analysed using interpretative phenomenological analysis. Results: Study 1: Three over-arching themes comprised patients’ experiences: (1) the initial consultation, (2) life after the consultation, and (3) patients’ reflections. Patients commented on the relief and reassurance experienced during the consultation but they perceived the decision making process mostly led by the physician. Lack of education and take-home materials distributed during the initial consultation was highlighted. Patients who had experienced stroke themselves or were caregivers, were more receptive to education aimed towards stroke risk reduction rather than bleeding risk. Warfarin monitoring was challenging for patients, however some patients perceived it as beneficial as it served to enhance patient-physician relationship. Study 2: Two over-arching themes emerged from physicians’ experiences: (1) communicating information and (2) challenges with OAC prescription for AF. Physicians’ approach to the consultation style shifted through a continuum of compliance-adherence-concordance during the consultation. They aimed for concordance, however challenges such as time and the perceived patient trust in them as the expert, led to physicians adopting a paternalistic approach. Physicians also pointed out challenges associated with guideline adherence and the need to adopt a multi-disciplinary approach, where other health professionals could provide on-going education. Conclusion: This programme of work has illustrated the benefit of taking an in depth phenomenological approach to understanding the lived experience of the physician-patient consultation. Together with the meta-synthesis, this work has strengthened the evidence base and demonstrated that there is a need to target patients' and physicians' ability to communicate with each other in a comprehensible way.

Aggregating preference ranking with fuzzy Data Envelopment Analysis

Selecting the best alternative in a group decision making is a subject of many recent studies. The most popular method proposed for ranking the alternatives is based on the distance of each alternative to the ideal alternative. The ideal alternative may never exist; hence the ranking results are biased to the ideal point. The main aim in this study is to calculate a fuzzy ideal point that is more realistic to the crisp ideal point. On the other hand, recently Data Envelopment Analysis (DEA) is used to find the optimum weights for ranking the alternatives. This paper proposes a four stage approach based on DEA in the Fuzzy environment to aggregate preference rankings. An application of preferential voting system shows how the new model can be applied to rank a set of alternatives. Other two examples indicate the priority of the proposed method compared to the some other suggested methods.

How weak categorizers based upon different principles strengthen performance

Combining the results of classifiers has shown much promise in machine learning generally. However, published work on combining text categorizers suggests that, for this particular application, improvements in performance are hard to attain. Explorative research using a simple voting system is presented and discussed in the light of a probabilistic model that was originally developed for safety critical software. It was found that typical categorization approaches produce predictions which are too similar for combining them to be effective since they tend to fail on the same records. Further experiments using two less orthodox categorizers are also presented which suggest that combining text categorizers can be successful, provided the essential element of ‘difference’ is considered.

Subject identification via ECG fiducial-based systems:influence of the type of QT interval correction

Electrocardiography (ECG) has been recently proposed as biometric trait for identification purposes. Intra-individual variations of ECG might affect identification performance. These variations are mainly due to Heart Rate Variability (HRV). In particular, HRV causes changes in the QT intervals along the ECG waveforms. This work is aimed at analysing the influence of seven QT interval correction methods (based on population models) on the performance of ECG-fiducial-based identification systems. In addition, we have also considered the influence of training set size, classifier, classifier ensemble as well as the number of consecutive heartbeats in a majority voting scheme. The ECG signals used in this study were collected from thirty-nine subjects within the Physionet open access database. Public domain software was used for fiducial points detection. Results suggested that QT correction is indeed required to improve the performance. However, there is no clear choice among the seven explored approaches for QT correction (identification rate between 0.97 and 0.99). MultiLayer Perceptron and Support Vector Machine seemed to have better generalization capabilities, in terms of classification performance, with respect to Decision Tree-based classifiers. No such strong influence of the training-set size and the number of consecutive heartbeats has been observed on the majority voting scheme.

Patients' and physicians' experiences of atrial fibrillation consultations and anticoagulation decision-making:a multi-perspective IPA design

OBJECTIVE: To explore patients' and physicians' experiences of atrial fibrillation consultations and oral anticoagulation decision-making. DESIGN: Multi-perspective interpretative phenomenological analyses. METHODS: Participants included small homogeneous subgroups: AF patients who accepted (n=4), refused (n=4), or discontinued (n=3) warfarin, and four physician subgroups (n=4 each group): consultant cardiologists, consultant general physicians, general practitioners and cardiology registrars. Semi-structured interviews were conducted. Transcripts were analysed using multi-perspective IPA analyses to attend to individuals within subgroups and making comparisons within and between groups. RESULTS: Three themes represented patients' experiences: Positioning within the physician-patient dyad, Health-life balance, and Drug myths and fear of stroke. Physicians' accounts generated three themes: Mechanised metaphors and probabilities, Navigating toward the 'right' decision, and Negotiating systemic factors. CONCLUSIONS: This multi-perspective IPA design facilitated an understanding of the diagnostic consultation and treatment decision-making which foregrounded patients' and physicians' experiences. We drew on Habermas' theory of communicative action to recommend broadening the content within consultations and shifting the focus to patients' life contexts. Interventions including specialist multidisciplinary teams, flexible management in primary care, and multifaceted interventions for information provision may enable the creation of an environment that supports genuine patient involvement and participatory decision-making.

Departmental elections and the changing landscape of French politics

The departmental elections of March 2015 redrew the French political landscape, setting the new terms of electoral competition in advance of the regional elections of December 2015 and, more critically, the presidential election of April–May 2017. These elections saw the far-right National Front (FN) come top in both rounds only to be outmanoeuvred by the mainstream parties and prevented from winning a single department. As a case study in vote–seat distortion, the elections highlighted a voting system effective in keeping the FN out of executive power but deficient in terms of democratic representation and inadequate as a response to the new tripartite realities of France's changing political landscape.

The experiences of con sultations on oral anticoagula-tion for AF:the importance of qualitative research incardiovascular sciences

Objectives: Multiple-perspective qualitative designs can aid researchersto develop a more multifaceted account of a phenomenon and as aform of triangulation of data. Two interlinking studies aimed toexplore patients’ and physicians’ experiences of atrial fibrillation (AF)and warfarin.Methods: Audio-recorded semistructured individual interviews wereused. Study 1: Three AF patient subgroups were interviewed (n = 11);accepted, refused, or discontinued warfarin. Study 2: Four physiciansubgroups (n = 16): consultant cardiologists, consultant general physi-cians, general practitioners, and cardiology registrars. Data was ana-lyzed using interpretative phenomenological analysis, a qualitativemethodology.Results: Study 1: Three overarching themes comprised patients’ experi-ences: the initial consultation, life after the consultation, and patients’reflections. Patients commented on the reassurance experienced duringthe consultation, but they perceived the decision-making processmostly led by the physician. Lack of education and take-home materi-als during the initial consultation were highlighted. Patients’ uptake ofinformation was influenced by past experiences and knowledge ofstroke and/or bleeding. Study 2: Two overarching themes covered phy-sicians’ experiences: communicating information and challenges withwarfarin prescription for AF. Physicians’ approach to the consultationstyle shifted through a continuum of compliance-adherence-concor-dance during the consultation. Time and the perceived patient trust inthem as the expert led to physicians to adopt a paternalistic approach.Guideline adherence and the need to adopt a multidisciplinaryapproach were pointed out as current challenges.Conclusion: There is a need to target patients’ and physicians’ abilityto communicate with each other in a comprehensible way. This projecthas illustrated the benefit of using a qualitative approach to under-stand the lived experience of the physician–patient consultation.Disclosure of Interest: None declare

The risk of re-intervention after endovascular aortic aneurysm repair

This thesis studies survival analysis techniques dealing with censoring to produce predictive tools that predict the risk of endovascular aortic aneurysm repair (EVAR) re-intervention. Censoring indicates that some patients do not continue follow up, so their outcome class is unknown. Methods dealing with censoring have drawbacks and cannot handle the high censoring of the two EVAR datasets collected. Therefore, this thesis presents a new solution to high censoring by modifying an approach that was incapable of differentiating between risks groups of aortic complications. Feature selection (FS) becomes complicated with censoring. Most survival FS methods depends on Cox's model, however machine learning classifiers (MLC) are preferred. Few methods adopted MLC to perform survival FS, but they cannot be used with high censoring. This thesis proposes two FS methods which use MLC to evaluate features. The two FS methods use the new solution to deal with censoring. They combine factor analysis with greedy stepwise FS search which allows eliminated features to enter the FS process. The first FS method searches for the best neural networks' configuration and subset of features. The second approach combines support vector machines, neural networks, and K nearest neighbor classifiers using simple and weighted majority voting to construct a multiple classifier system (MCS) for improving the performance of individual classifiers. It presents a new hybrid FS process by using MCS as a wrapper method and merging it with the iterated feature ranking filter method to further reduce the features. The proposed techniques outperformed FS methods based on Cox's model such as; Akaike and Bayesian information criteria, and least absolute shrinkage and selector operator in the log-rank test's p-values, sensitivity, and concordance. This proves that the proposed techniques are more powerful in correctly predicting the risk of re-intervention. Consequently, they enable doctors to set patients’ appropriate future observation plan.

Oral anticoagulation in atrial fibrillation, the patients and physicians experiences of the consultation:a qualitative study

Background: Oral anticoagulation (OAC) reduces stroke risk in patients with atrial fibrillation (AF), however it is still underutilized and sometimes refused by patients. This project was divided in two inter-related studies. Study 1 explored the experiences that influence prescription of OAC by physicians. Study 2 explored the experiences which influence patients' decisions to accept, decline or discontinue OAC. Methods: Semi-structured individual interviews were conducted in both studies. In Study 1four sub-groups of physicians (n = 16) experienced with OAC in AF were interviewed: consultant cardiologists, consultant general physicians, general practitioners and cardiology registrars. In Study 2 three sub-groups of patients (n = 11) diagnosed with AF were interviewed; those who accepted, refused, and who discontinued warfarin. Results: Study 1: Two over-arching themes emerged from doctors' experiences: (1) communicating information and (2) challenges with OAC prescription for AF. Physicians still adopt a paternalistic approach to decision-making. They should instead motivate patients to take part in treatment discussions and choices should reflect the patient's needs and concerns. Physician education should focus more on communication skills, individualised care and time-management as these are critical for patient adherence. Continuous OAC education for AF should adopt a multi-disciplinary approach. Further, interpreters should also be educated on medical communication skills. Study 2: Three over-arching themes comprised patients' experiences: (1) the initial consultation, (2) life after the consultation, and (3) patients' reflections. Patient education during the initial consultation was critical in increasing patient's knowledge of OAC. On-going patient education is imperative to maintain adherence. Patients valued physicians' concern for their needs during decision-making. Patients who had experience of stroke were more receptive to education aimed towards stroke risk reduction rather than bleeding risk. Patients' perceptions of warfarin are also influenced by the media. Comment: Qualitative research is crucial in exploring barriers to treatment as it provides an excellent insight into patients' experiences of healthcare. A patient-centred approach should be adopted and incorporated into physicians' education. Education and patient involvement in the decision-making process is essential to promote treatment acceptance and long-term adherence