University of Portsmouth

About: University of Portsmouth is a education organization based out in Portsmouth, Portsmouth, United Kingdom. It is known for research contribution in the topics: Population & Galaxy. The organization has 5452 authors who have published 14256 publications receiving 424346 citations. The organization is also known as: Portsmouth and Gosport School of Science and Art & Portsmouth and Gosport School of Science and the Arts.

A DEMATEL-based completion method for incomplete pairwise comparison matrix in AHP

Abstract: Pairwise comparison matrix (PCM) as a crucial component of Analytic Hierarchy Process (AHP) presents the preference relations among alternatives. However, in many cases, the PCM is difficult to be completed, which obstructs the subsequent operations of the classical AHP. In this paper, based on decision-making and trial evaluation laboratory (DEMATEL) method which has ability to derive the total relation matrix from direct relation matrix, a new completion method for incomplete pairwise comparison matrix (iPCM) is proposed. The proposed method provides a new perspective to estimate the missing values in iPCMs with explicit physical meaning, which is straightforward and flexible. Several experiments are implemented as well to present the completion ability of the proposed method and some insights into the proposed method and matrix consistency.

Experimental gentamicin nephrotoxicity and agents that modify it: a mini-review of recent research.

Abstract: The aminoglycoside antibiotic gentamicin (GM) is still widely used against infections by Gram-positive and Gram-negative aerobic bacteria. Its therapeutic efficacy, however, is limited by renal impairment that occurs in up to 30% of treated patients. The drug may accumulate in epithelial tubular cells causing a range of effects starting with loss of the brush border in epithelial cells and ending in overt tubular necrosis, activation of apoptosis and massive proteolysis. GM also causes cell death by generation of free radicals, phospholipidosis, extracellular calcium-sensing receptor stimulation and energetic catastrophe, reduced renal blood flow and inflammation. Many drugs have been shown to either ameliorate or potentiate GM nephrotoxicity. This article aims at updating the literature that has been published in the past decade on the effects of agents that either ameliorate or augment the nephrotoxicity of this aminoglycoside. Notable among the new ameliorating procedures are gene therapy, such as intravenous cell therapy with serum amyloid A protein-programmed cells, and the use of some novel antioxidant agents and oils of natural origin. These include, for example, green tea, garlic saffron, grape seed extracts as well as sesame and oleanolic oils. Agents that may augment GM nephrotoxicity include indomethacin, cyclosporin, uric acid and the Ca(++) -channel blocker verapamil. Most of the nephroprotective agents mentioned here have not been tested in large controlled clinical trials. Because of their relative safety and effectiveness, antioxidant agents seem to be good candidates for testing in humans.

Dimensional change in complete dentures fabricated by injection molding and microwave processing

Abstract: Statement of problem Acrylic resin complete dentures undergo dimensional changes during polymerization Techniques with injection molding and polymerization and microwave polymerization are reported to reduce these changes and thereby improve clinical fit These dimensional changes need to be quantified Purpose The purpose of this study was to compare differences in dimensional changes of simulated maxillary complete dentures during polymerization and storage in water after injection molding and conventional polymerization, or microwave polymerization against a control of conventionally packed and polymerized simulated maxillary complete dentures Material and methods Forty identical maxillary denture bases were prepared in dental wax with anatomic teeth They were invested and the wax eliminated from the molds Ten specimens each were randomly assigned to 1 of 4 groups Group 1 was compression molded and conventionally polymerized; group 2 was injection molded and conventionally polymerized (Success); group 3 was injection molded and microwave polymerized (Acron MC); and group 4 was injection molded and microwave polymerized (Microbase) Intermolar width and changes in vertical dimension of occlusion, were determined after polymerization and after storage in water for 28 days Measurements in triplicate were made between points scribed on the second molar teeth with a traveling microscope (accurate to 0005 mm) Vertical dimension of occlusion was measured between points scribed on the upper and lower members of an articulator by use of an internal micrometer (accurate to 005 mm) Data were analyzed by use of a 1-way analysis of variance with Tukey post-hoc contrasts ( P Results Polymerization contractions (intermolar widths) for each group were: group 1, −024%; group 2, −027%; group 3, −035%; and group 4, −037% The Microbase specimens had greater shrinkage than conventionally polymerized specimens, but there were no significant differences between the groups All injection methods had less postpolymerization increase in vertical dimension of occlusion (063 to 041 mm) than the conventional Trevalon control (074 mm), but only group 4 was significantly different ( P Conclusion Within the limitations of this study, injection molding resulted in a slightly less increase of vertical dimension of occlusion than conventional polymerization techniques, the difference being significant for Microbase compared with the conventional Trevalon control (J Prosthet Dent 2003;89:37-44)

Output Substitution in Multi-Species Trawl Fisheries: Implications for Quota Setting

Abstract: In most multi-species fisheries managed through output controls, total allowable catches (TACs) are set primarily on the basis of biological considerations, usually on a species by species basis. An implicit assumption of management is that fishers are able to adjust their product mix in line with these quotas. If this is not the case, then over-quota catch occurs, leading to either illegal landings or discards. In either case, the effectiveness of the TAC in conserving the resource is reduced. In this paper we show that in the case of multi-species fisheries that exhibit jointness in production, setting TACs on an individual species' basis is inappropriate. In particular, we quantify technical interactions through the estimation of a multi-output distance function for the UK North Sea beam and otter trawl fisheries, and find that in most cases, the potential of substitutability between the main and alternative species is relatively small. We argue that failure to quantify and integrate these technical interactions in the construction of management instruments for fisheries regulation, may result in increased discarding, illegal fishing and potentially lower than expected future yields.

Public attitudes towards the environmental impact of salmon aquaculture in Scotland

Abstract: This paper reports the results of a survey of public attitudes towards aquaculture, using salmon farming in Scotland as a case study. The aims have been to identify the priority that people attach to the environmental performance of the salmon aquaculture industry, relative to other objectives, and to measure the economic benefits to society from salmon farmed using methods that cause less organic pollution. The results indicate that the public attach a relatively high importance to minimizing environmental damage from aquaculture, and this has its parallel in the finding that people are willing to pay a price premium for salmon produced in a more environmentally benign way. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.