783 research outputs found

    OWL-Miner: Concept Induction in OWL Knowledge Bases

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    The Resource Description Framework (RDF) and Web Ontology Language (OWL) have been widely used in recent years, and automated methods for the analysis of data and knowledge directly within these formalisms are of current interest. Concept induction is a technique for discovering descriptions of data, such as inducing OWL class expressions to describe RDF data. These class expressions capture patterns in the data which can be used to characterise interesting clusters or to act as classifica- tion rules over unseen data. The semantics of OWL is underpinned by Description Logics (DLs), a family of expressive and decidable fragments of first-order logic. Recently, methods of concept induction which are well studied in the field of Inductive Logic Programming have been applied to the related formalism of DLs. These methods have been developed for a number of purposes including unsuper- vised clustering and supervised classification. Refinement-based search is a concept induction technique which structures the search space of DL concept/OWL class expressions and progressively generalises or specialises candidate concepts to cover example data as guided by quality criteria such as accuracy. However, the current state-of-the-art in this area is limited in that such methods: were not primarily de- signed to scale over large RDF/OWL knowledge bases; do not support class lan- guages as expressive as OWL2-DL; or, are limited to one purpose, such as learning OWL classes for integration into ontologies. Our work addresses these limitations by increasing the efficiency of these learning methods whilst permitting a concept language up to the expressivity of OWL2-DL classes. We describe methods which support both classification (predictive induction) and subgroup discovery (descrip- tive induction), which, in this context, are fundamentally related. We have implemented our methods as the system called OWL-Miner and show by evaluation that our methods outperform state-of-the-art systems for DL learning in both the quality of solutions found and the speed in which they are computed. Furthermore, we achieve the best ever ten-fold cross validation accuracy results on the long-standing benchmark problem of carcinogenesis. Finally, we present a case study on ongoing work in the application of OWL-Miner to a real-world problem directed at improving the efficiency of biological macromolecular crystallisation

    Understanding Diffraction in Volume Gratings and Holograms

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    Restorative practice and behaviour management in schools: discipline meets care.

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    The history of restorative practices in New Zealand schools is directly related to projects such as the Suspension Reduction Initiative (SRI) and the more recent Student Engagement Initiative (SEI); thus the origins of restorative practices in schools are linked with behaviour management and school discipline. During the same period, teachers' work has become more complex: They are working with an increasingly diverse range of students, which in turn requires epistemologically diverse teaching and relationship-building approaches to ensure maximum participation for all. Teachers are looking for new and better ways to interact with students in their classrooms, and those responsible for disciplinary systems are looking to restorative practice for new ways to resolve the increasing range and number of difficulties between teachers and students, students and other students, and between the school and parents. Restorative practices (RP) are currently seen as a way of achieving all this, so they carry a huge burden of hope. Relationship skills are a key competency in the new curriculum, and the philosophy of restoration offers both a basis for understanding and a process for putting this agenda into practice. In effect, it means educating for citizenship in a diverse world, including teaching the skills of conflict resolution. If we accept this philosophy, the curriculum for teacher education will require significant changes in what students are taught about behaviour and classroom management

    Orienting asymmetries in dogs’ responses to different communicatory components of human speech

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    It is well established that in human speech perception the left hemisphere (LH) of the brain is specialized for processing intelligible phonemic (segmental) content (e.g., [1–3]), whereas the right hemisphere (RH) is more sensitive to pro- sodic (suprasegmental) cues [4, 5]. Despite evidence that a range of mammal species show LH specialization when pro- cessing conspecific vocalizations [6], the presence of hemi- spheric biases in domesticated animals’ responses to the communicative components of human speech has never been investigated. Human speech is familiar and relevant to domestic dogs (Canis familiaris), who are known to perceive both segmental phonemic cues [7–10] and supra- segmental speaker-related [11, 12] and emotional [13] proso- dic cues. Using the head-orienting paradigm, we presented dogs with manipulated speech and tones differing in segmental or suprasegmental content and recorded their orienting responses. We found that dogs showed a sig- nificant LH bias when presented with a familiar spoken command in which the salience of meaningful phonemic (segmental) cues was artificially increased but a significant RH bias in response to commands in which the salience of intonational or speaker-related (suprasegmental) vocal cues was increased. Our results provide insights into mech- anisms of interspecific vocal perception in a domesticated mammal and suggest that dogs may share ancestral or convergent hemispheric specializations for processing the different functional communicative components of speech with human listeners

    Magnetic fluctuations in the reversed field pinch

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    Arrays of edge magnetic coils and an insertable magnetic probe have been used to study the behaviour of the magnetic fluctuations in the HBTX1A Reversed Field Pinch. EDGE COILS: In the sustainment phase of the discharge poloidal arrays of edge coils show that the superficially random fluctuations can be attributed almost entirely to global modes of poloidal mode number m &ap; 0 and 1 provided account is taken of the toroidal distortion of these instabilities. A toroidal array of edge coils discloses a broad spectrum of toroidal mode numbers with a peak at |n| &ap; 10 and significant variation with time and frequency. Cross correlation between signals from poloidal and toroidal edge coil arrays establishes that the |n| &ap; 10 is m = 1, a set of helical modes resonant inside the reversal surface and also shows the presence of m = 0, |n| &ap; 0. Timescales of the measured fluctuations indicate that the instabilities are probably resistive in character and mode amplitudes are such that island overlap and magnetic field ergodization should occur. The energy confinement time due to stochastic transport, estimated directly from the measured fluctuations, is consistent with that experimentally observed. Studies of the edge magnetic fluctuations have been applied to discharges of differing conditions and in the termination and current set-up phases. Results show that, although systematic trends in the amplitude of the fluctuations occur, mode numbers and frequencies appear invarient with respect to changes in plasma current and filling pressure. At high values of [theta] an |n| &ap; 3 mode becomes of equal significance to the m = 1, |n| &ap; 10 modes. Estimates of the safety factor indicate that, although the observed timescale of this mode would label it resistive, it is not resonant. The structure of the global fluctuations in the current set-up phase appears very similar to that during sustainment, although the amplitude is higher. In the termination phase the fluctuations show several differences in the frequency and mode numbers. However, after reversal is lost, the observed frequencies correspond to resistive timescales rather than the Alfven timescale expected for ideal modes. INSERTABLE PROBE: A statistical method for determining the radial amplitude distributions of instabilities is presented. This is used to analyse probe data from which it is possible to distinguish three types of instability. At low frequencies (4 20 kHz) the dominant internal fluctuations are to be associated with the global m = 1, |n| &ap; 10 resistive modes seen by the edge coils. These modes possess a radial structure in agreement with that predicted by a linear tearing mode stability analysis of the measured equilibrium. At similar amplitudes to these modes there is also a short correlation component ([lambda]r = 3 cm) which is peaked in the central regions of the discharge. At high frequencies (>30 kHz) this local turbulence dominates over the global modes. Finally, at about the peak power of the dominant global modes and with a similar frequency dependence, an m = 1 mode with some ideal characteristics is observed. Stability calculations show that ideal modes that are either destabilised by a resistive shell or whose growth rates are reduced by a resistive liner would have the same radial structure and timescales as this mode.<p

    Short term doxycycline treatment induces sustained improvement in myocardial infarction border zone contractility.

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    Decreased contractility in the non-ischemic border zone surrounding a MI is in part due to degradation of cardiomyocyte sarcomeric components by intracellular matrix metalloproteinase-2 (MMP-2). We recently reported that MMP-2 levels were increased in the border zone after a MI and that treatment with doxycycline for two weeks after MI was associated with normalization of MMP-2 levels and improvement in ex-vivo contractile protein developed force in the myocardial border zone. The purpose of the current study was to determine if there is a sustained effect of short term treatment with doxycycline (Dox) on border zone function in a large animal model of antero-apical myocardial infarction (MI). Antero-apical MI was created in 14 sheep. Seven sheep received doxycycline 0.8 mg/kg/hr IV for two weeks. Cardiac MRI was performed two weeks before, and then two and six weeks after MI. Two sheep died prior to MRI at six weeks from surgical/anesthesia-related causes. The remaining 12 sheep completed the protocol. Doxycycline induced a sustained reduction in intracellular MMP-2 by Western blot (3649±643 MI+Dox vs 9236±114 MI relative intensity; p = 0.0009), an improvement in ex-vivo contractility (65.3±2.0 MI+Dox vs 39.7±0.8 MI mN/mm2; p&lt;0.0001) and an increase in ventricular wall thickness at end-systole 1.0 cm from the infarct edge (12.4±0.6 MI+Dox vs 10.0±0.5 MI mm; p = 0.0095). Administration of doxycycline for a limited two week period is associated with a sustained improvement in ex-vivo contractility and an increase in wall thickness at end-systole in the border zone six weeks after MI. These findings were associated with a reduction in intracellular MMP-2 activity

    Urban places, urban pleasures: the cultural use of civic space

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    Humanities Research Group Working Papers 10https://scholar.uwindsor.ca/hrg-working-papers/1009/thumbnail.jp

    Development and validation of a preference based measure derived from the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) for use in cost utility analyses

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    <p>Abstract</p> <p>Background</p> <p>Pulmonary Hypertension is a severe and incurable disease with poor prognosis. A suite of new disease-specific measures – the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) – was recently developed for use in this condition. The purpose of this study was to develop and validate a preference based measure from the CAMPHOR that could be used in cost-utility analyses.</p> <p>Methods</p> <p>Items were selected that covered major issues covered by the CAMPHOR QoL scale (activities, travelling, dependence and communication). These were used to create 36 health states that were valued by 249 people representative of the UK adult population, using the time trade-off (TTO) technique. Data from the TTO interviews were analysed using both aggregate and individual level modelling. Finally, the original CAMPHOR validation data were used to validate the new preference based model.</p> <p>Results</p> <p>The predicted health state values ranged from 0.962 to 0.136. The mean level model selected for analyzing the data had good explanatory power (0.936), did not systematically over- or underestimate the observed mean health state values and showed no evidence of auto correlation in the prediction errors. The value of less than 1 reflects a background level of ill health in state 1111, as judged by the respondents. Scores derived from the new measure had excellent test-retest reliability (0.85) and construct validity. The CAMPHOR utility score appears better able to distinguish between WHO functional classes (II and III) than the EQ-5D and SF-6D.</p> <p>Conclusion</p> <p>The tariff derived in this study can be used to classify an individual into a health state based on their responses to the CAMPHOR. The results of this study widen the evidence base for conducting economic evaluations of interventions designed to improve QoL for patients with PH.</p
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