Cancer-radiotherapy equipment as a cause of soft errors in electronic equipment

The undesirable production of secondary neutrons by cancer-radiotherapy linear accelerators (linac) has been demonstrated to cause soft errors in nearby electronics through the /sup 10/B(n,a)/sup 7/Li reaction. /sup 10/B is a component in the BPSG used as a dielectric material in some integrated-circuit (IC) fabrication processes.     

Automatic diatom identification using contour analysis by morphological curvature scale spaces

A method for automatic identification of diatoms (single-celled algae with silica shells) based on extraction of features on the contour of the cells by multi-scale mathematical morphology is presented. After extracting the contour of the cell, it is smoothed adaptively, encoded using Freeman chain code, and converted into a curvature representation which is invariant under translation and scale change. A curvature scale space is built from these data, and the most important features are extracted from it by unsupervised cluster analysis. The resulting pattern vectors, which are also rotation-invariant, provide the input for automatic identification of diatoms by decision trees and k-nearest neighbor classifiers. The method is tested on two large sets of diatom images. The techniques used are applicable to other shapes besides diatoms. Andrei C. Jalba received his B.Sc. (1998) and M.Sc. (1999) in Applied Electronics and Information Engineering from “Politehnica” University of Bucharest, Romania. He recently obtained a Ph.D. degree at the Institute for Mathematics and Computing Science of the University of Groningen, where he now is a postdoctoral researcher. His research interests include computer vision, pattern recognition, image processing, and parallel computing. Michael Wilkinson obtained an M.Sc. in astronomy from the Kapteyn Laboratory, University of Groningen (RuG) in 1993, after which he worked on image analysis of intestinal bacteria at the Department of Medical Microbiology, RuG. This work formed the basis of his Ph.D. at the Institute of Mathematics and Computing Science (IWI), RuG, in 1995. He was appointed as researcher at the Centre for High Performance Computing (also RuG) working on simulating the intestinal microbial ecosystem on parallel computers. During that time he edited the book “Digital Image Analysis of Microbes” (John Wiley, UK, 1998) together with Frits Schut. After this he worked as a researcher at the IWI on image analysis of diatoms. He is currently assistant professor at the IWI. Jos B.T.M. Roerdink received his M.Sc. (1979) in theoretical physics from the University of Nijmegen, the Netherlands. Following his Ph.D. (1983) from the University of Utrecht and a 2-year position (1983--1985) as a Postdoctoral Fellow at the University of California, San Diego, both in the area of stochastic processes, he joined the Centre for Mathematics and Computer Science in Amsterdam. There he worked from 1986-1992 on image processing and tomographic reconstruction. He was appointed associate professor (1992) and full professor (2003), respectively, at the Institute for Mathematics and Computing Science of the University of Groningen, where he currently holds a chair in Scientific Visualization and Computer Graphics. His current research interests include biomedical visualization, neuroimaging and bioinformatics. Micha Bayer graduated from St. Andrews University, Scotland, with an M.Sc. in Marine Biology in 1994. He obtained his Ph.D. in Marine Biology from there in 1998, and then followed this up with two postdoctoral positions at the Royal Botanic Garden Edinburgh, Scotland, first on the ADIAC and then on the DIADIST project. In both of these projects he was responsible for establishing the collections of diatom training data to be used for the pattern recognition systems. From 2002–2003 he was enrolled for an M.Sc. in information technology at the University of Glasgow, Scotland, and is now working as a grid developer at the National e-Science Centre at Glasgow University. Stephen Juggins is a senior lecturer at the School of Geography, Politics and Sociology, University of Newcastle. His research focuses on the use of diatoms for monitoring environmental change and on the analysis of ecological and palaeoecological data. He has worked in Europe, North America and Central Asia on problems of river water quality, historical lake acidification, coastal eutrophication and Quaternary climate change.     

Liquid‐crystal displays using printed plastic TFT backplanes

Abstract— In this paper, we present results from a new liquid crystal over plastic printed thin‐film‐transistor (TFT) display. The display demonstrator shows that the processing incompatibilities between the plastic TFT backplane and the liquid‐crystal materials can be addressed to make a stable twisted‐nematic structure. New fabrication processes such as the photo‐alignment of liquid crystals have made it possible to create a new generation of displays, which pave the way towards fully integrated plastic liquid‐crystal‐display technologies.     

Tests of the fidelity of lake sediment core records of mercury deposition to known histories of mercury contamination

There has been recent controversy over the discrimination between natural and anthropogenic loadings of mercury to lakes. Sediment core profiles have been interpreted as evidence that inputs to lakes have increased. Some investigators have argued, however, that mercury may be sufficiently mobile in sediments to generate profiles that are misinterpreted as historical records. This argument can be tested where the histories of inputs of mercury are known independently from other kinds of information. We have such cases in Canadian lakes and we have been able to assemble sediment core records for comparison with known source histories. Three cases are represented by Clay Lake in Ontario where the source was a chlor-alkali plant with a known history of mercury discharges, Giauque Lake in the Northwest Territories where mercury was used at a gold mine to extract gold from ore, and Stuart Lake in British Columbia where a mercury mine operated for a known period at Pinchi Lake, the lake immediately upstream from Stuart Lake. In these cases lake sediment cores were dated using lead-210 and cesium-137 and then slices were analysed for mercury. The histories of mercury deposition derived from the cores agreed well with the known histories of inputs.     

Horse Chestnut - Aesculus Hippocastanum: Potential Applications in Cosmetic Skin-care Products

In addition to the well reported beneficial effects of horse chestnut (Aesculus hippocastanum) extracts on venous insufficiency and associated conditions, such preparations also have many potential positive pharmacological effects on the skin. Extracts from this species, and in particular, those based on horse chestnut seeds, contain saponins, known collectively as 'aescin', which have a gentle soapy feel, and are potent anti-inflammatory compounds. Saponins, such as escin, also reduce capillary fragility, and therefore help to prevent leakage of fluids into surrounding tissues, which can cause swelling. An extract of horse chestnut has recently been shown to have one of the highest 'active-oxygen' scavenging abilities of 65 different plant extracts tested. Such extracts are more powerful anti-oxidants than vitamin E, and also exhibit potent cell-protective effects, which are linked to the well-known anti-ageing properties of anti-oxidants. The extract is also rich in a number of flavonoids, such as derivatives of quercetin and kaempferol. Flavonoids also have protective effects on blood vessels, and are well-known, powerful anti-oxidants.     

New Materials and Processes for Integrated Optics

Materials and processes for integrated optics are faced with increasing demands from telecommunications and instrumentation applications. Progress in three aspects of novel materials and processes are described: titanium-diffused sapphire waveguides and lasers, interferometric excimer laser ablation of waveguide gratings, and surface studies by waveguide surface plasmon resonance.     

Evidence that trypanothione reductase is an essential enzyme in Leishmania by targeted replacement of the tryA gene locus

Trypanothione reductase (TR), a flavoprotein oxidoreductase central to the unique thiol-redox system that operates in trypanosomatid protozoa, has been proposed as a potential target for the chemotherapy of trypanosomatid infections. In this study, targeted gene replacement was used to obtain evidence that TR is an essential cellular component and that its physiological function is crucial for parasite survival. Precise replacement of the Leishmania donovani tryA gene encoding TR was only possible upon simultaneous expression of the tryA coding region from an episome; in its absence, attempted removal of the last tryA allele invariably led to the generation of an extra copy of tryA, seemingly as a result of selective chromosomal polysomy. Partial replacement mutants were drastically affected in their ability to survive inside cytokine-activated macrophages in a murine model of Leishmania infection. As no compensatory mechanism for the partial loss of TR activity was observed in these mutants and as it was not possible to obtain viable Leishmania devoid of TR catalytic activity, specific inhibitors of this enzyme are likely to be useful anti-leishmanial agents for chemotherapeutic use.     

S-fluoxetine in the prophylaxis of migraine: a phase II double-blind randomized placebo-controlled study

A tubular bioassay was used to measure analytically the local production and concentration of the antifungal Trichoderma secondary metabolite 6-n-pentyl-2H-pyran-2-one (6PAP) at the Trichoderma antagonist/pathogen interface. 6PAP levels significantly increased in the presence of the pathogen Botrytis cinerea, typically 300-700%, and were highest near the pathogen source. The level of response for a particular Trichoderma isolate was found to vary with the test organism used. Two products produced by biotransformation of 6PAP by B. cinerea in response to the interaction were also detected.     

Cholesterol, endothelial function and cardiovascular disease

Poster presentations have proved to be a popular method of displaying information at conferences, and are being used increasingly as a teaching method. Innovative strategies for teaching and assessing research need to facilitate students' achievement of research skills required for practice. These are outlined by the Department of Health, and emphasize the development of research literacy. Using the poster presentation as a teaching and assessing strategy on diploma level courses (Project 2000 and ENB 870 introduction to the Understanding and Application of Research) has proved to be valuable in developing vital research awareness skills and in harnessing enthusiasm for research. Students imply a sense of achievement gained through the process of developing the poster and the production of the poster itself. Herein lies the value of the poster presentation, for it allows the development of crucial research literacy skills which can be widely used in professional practice and future professional education.     

New endeavors and innovative programs in end of life care

This paper presents summaries of initiatives and demonstration programs developed by professional and patient care organizations to improve care at the end of life.