Coventry University

About: Coventry University is a education organization based out in Coventry, United Kingdom. It is known for research contribution in the topics: Context (language use) & Population. The organization has 4964 authors who have published 12700 publications receiving 255898 citations. The organization is also known as: Lanchester Polytechnic & Coventry Polytechnic.

Assessing lake eutrophication using chironomids: understanding the nature of community response in different lake types

Abstract: 1. Total phosphorus (TP) and chlorophyll a (Chl a) chironomid inference models (Brodersen & Lindegaard, 1999; Brooks, Bennion & Birks, 2001) were used in an attempt to reconstruct changes in nutrients from three very different lake types. Both training sets were expanded, particularly at the low end of the nutrient gradient, using contemporary chironomid assemblages and environmental parameters from 12 British lakes, although this had little improvement on the model performances. 2. Dissimilarity analyses showed that the historic chironomid assemblages did not have good analogues in the original calibration or extended datasets. However, since the transfer functions are based on weighted averages of the trophic optima for the taxa present and not on community similarities, reasonable downcore inferences were produced. Ordination analyses also showed that the lakes retain their 'identity' over time, as the sample dissimilarities within lakes were less than the dissimilarities between lakes. 3. Analysis of the three historic lake profiles showed a range of chironomid community responses to lake development. Chironomids from a shallow lake, Slapton Ley, responded indirectly to nutrient enrichment (TP), probably through altered substrate, macrophyte and fish conditions, rather than directly to primary productivity (Chl a). A stratified lake, Old Mill Reservoir, showed a loss of the profundal chironomid fauna due to increasing primary productivity (Chl a) coupled with increasing hypoxia. A response to nutrients (TP or total nitrogen (TN)) at this site is also indirect, and the TP reconstruction therefore cannot be reliably interpreted. The third lake, March Ghyll Reservoir has little change in historic chironomid communities, suggesting that this well mixed, relatively unproductive lake has changed less than the other lakes. 4. Using chironomids to reconstruct nutrient histories does not follow a simple scheme. The response to changes in nutrients may be direct, but mediated through other ecosystem components. As alternative stable states are possible at a given level of TP it is also likely that alternative chironomid communities exist under similar nutrient conditions. Changes in biological communities can thus occur over thresholds, and it is only biological proxies that can reflect such ecosystem switches within palaeoenvironmental investigations.

Hybrid genetic algorithms for bin-packing and related problems

Abstract: The genetic algorithm (GA) paradigm has attracted considerable attention as a promising heuristic approach for solving optimization problems. Much of the development has related to problems of optimizing functions of continuous variables, but recently there have been several applications to problems of a combinatorial nature. What is often found is that GAs have fairly poor performance for combinatorial problems if implemented in a naive way, and most reported work has involved somewhat ad hoc adjustments to the basic method. In this paper, we will describe a general approach which promises good performance for a fairly extensive class of problems by hybridizing the GA with existing simple heuristics. The procedure will be illustrated mainly in relation to the problem ofbin-packing, but it could be extended to other problems such asgraph partitioning, parallel-machine scheduling andgeneralized assignment. The method is further extended by usingproblem size reduction hybrids. Some results of numerical experiments will be presented which attempt to identify those circumstances in which these heuristics will perform well relative to exact methods. Finally, we discuss some general issues involving hybridization: in particular, we raise the possibility of blending GAs with orthodox mathematical programming procedures.

Association between radiographic joint space narrowing, function, pain and muscle power in severe osteoarthritis of the knee

Abstract: Objective: To examine the association between radiographic classification of severe knee osteoarthritis and measurements of function, pain and power.Design: Cross-sectional study.Setting: Specialist orthopaedic hospital.Subjects: One hundred and twenty-three patients on the waiting list for elective knee arthroplasty.Outcome measures: Weight-bearing antero-posterior radiographs scored for severity of osteoarthritis using the Kellgren and Lawrence scale. Function measured using the function subscale of the WOMAC (Western Ontario and McMaster Universities) index, timed tests of walking speed and sit-to-stand. Pain measured using the pain subscale of the WOMAC index and a visual analogue scale. Extensor strength of the lower limb measured with the leg extensor power rig.Results: Within any radiographic grade there was considerable variation in function: WOMAC function for patients with grade 2 mean 64 (47 / 86), grade 3 mean 47 (12 / 89) grade 4 mean 45 (2 / 92). There was poor correlation between radiograph...

A fuzzy logic based-method for prognostic decision making in breast and prostate cancers

Abstract: Accurate and reliable decision making in oncological prognosis can help in the planning of suitable surgery and therapy, and generally, improve patient management through the different stages of the disease. In recent years, several prognostic markers have been used as indicators of disease progression in oncology. However, the rapid increase in the discovery of novel prognostic markers resulting from the development in medical technology, has dictated the need for developing reliable methods for extracting clinically significant markers where complex and nonlinear interactions between these markers naturally exist. The aim of this paper is to investigate the fuzzy k-nearest neighbor (FK-NN) classifier as a fuzzy logic method that provides a certainty degree for prognostic decision and assessment of the markers, and to compare it with: 1) logistic regression as a statistical method and 2) multilayer feedforward backpropagation neural networks an artificial neural-network tool, the latter two techniques having been widely used for oncological prognosis. In order to achieve this aim, breast and prostate cancer data sets are considered as benchmarks for this analysis. The overall results obtained indicate that the FK-NN-based method yields the highest predictive accuracy, and that it has produced a more reliable prognostic marker model than both the statistical and artificial neural-network-based methods.

Alienation, agency and authenticity: a synthesis of the literature on student engagement

Abstract: In recent years, a number of authors have undertaken extensive reviews of the international research literature to investigate student engagement in higher education. This article presents the findings of a study that synthesised the qualitative research literature systematically, through the use of qualitative research synthesis. The purpose of the article was not only to synthesise the literature, but also to examine and present the concepts and themes that recurred across the student engagement literature in terms of students' conceptions of engagement. The implications for enhancing student engagement practices are also considered in relation to pedagogical design decisions.