Computational medicine: bioelectric field problems

Applications of large-scale computer modeling and simulation to a class of bioelectric field problems in a variety of biomedical research areas, from single cells to full human structures, are described. The authors focus on a specific subset of bioelectric field problems that have applications in electrocardiography and electroencephalography. The physics and physiology of bioelectric volume conductors are introduced. A specific computational example and the authors' view on the future direction of computational medicine are presented     

Editorial.

With this volume, the 47-year old Canadian Journal of Psychology takes a new name and makes a renewed commitment. In retitling the journal the Canadian Journal of Experimental Psychology, the intention is to reflect more clearly what has always been the major goal of the journal--to publish the best new research in experimental psychology, both Canadian and international, in both French and English. I am honoured to become the tenth editor of the major journal for experimental psychology in Canada. CJP has served the field very well; my primary goal is to ensure that CJEP continues to do so. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stable Oxygen and Carbon Isotopic Compositions of Lates stappersii Otoliths from Lake Tanganyika,East Africa

In this study, we measured growth trends in oxygen and carbon isotopic ratios in whole sagittal otoliths from three adult centropomid fish (Lates stappersii) from each of three sub-basins of Lake Tanganyika, East Africa. Sampling density was 20 to 50 samples per otolith. Both δ¹⁸O and δ¹³C values increase with age. The δ¹⁸O data suggest that otoliths were precipitated near the expected equilibrium with the ambient environment (ca. +3.5‰) and support a migration pattern from surface waters during larval stages to deeper waters (40 to 80 m) for mature fish. Relatively high δ¹⁸O values in the southern sub-basin are consistent with cooler temperatures in the region during seasonal upwelling. The δ13C increase from otolith core to edge is large (up to 4‰) and is interpreted as due to ontogenetic changes in diet and contributions from a decrease in the proportion of respired CO₂ incorporated into otolith carbonate as metabolic rates of the fish dropped with maturity. The data seem to successfully reveal life strategy and migration patterns of L. stappersii, document regional differences in lake conditions, and provide a record of temperature within the water column during which the fish lived. Higher resolution studies and analyses of historical samples could be used to constrain modern and past growth patterns, and to reconstruct past temperature gradients and productivity patterns in the lake.     

éditorial.

This issue begins with an invited paper by Ronald Melzack, continuing the "Distinguished Contribution Series" begun in 1990 by my predecessor, Gordon Winocur. Professor Melzack is known world-wide for his research on pain. In 1965, together with Patrick Wall, he proposed the gate control theory, an entirely new conception of pain. For the first time, there was an explicit physiological model emphasizing the role played by the brain as well as by the spinal cord, leading to a new integration of psychological and physiological contributions to pain, as well as to new avenues for the control of pain. This theory has been highly influential, as a quick look in virtually any textbook in biology or medicine will confirm. Professor Melzack's continuing development of his ideas is presented with remarkable clarity in his books and in his many journal articles. It is, therefore, especially exciting for CJEP to be the first to publish a sketch of his new neuromatrix theory. When the book developing this theory is published, it too will no doubt have an immediate and major impact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Training for an agricultural discrimination task

Skeleton weed, centaurea juncea, is a declared weed in Western Australia because it competes with grain crops for nutrients and moisture. When it is found during harvesting, mechanised teams search and eradicate it. In an earlier report of field trials (Hartley et al, 1989) it was reported that search teams' detection rate was poor and since search teams had usually never seen skeleton weeds, visual discrimination learning was to be expected and observed during searches. The present study investigated the nature of this discrimination learning in a laboratory by developing a training programme of colour photographic slides of weeds in stubble. Subjects receiving specific training with feedback on their performance compared with those receiving pseudo-training showed a significant improvement in detections. Subsequently the benefit of the programme was validated in a field trial.     

Incremental Evolution in ANNs: Neural Nets which Grow

This paper explains the optimisation of neuralnetwork topology using Incremental Evolution;that is, by allowing the network to expand byadding to its structure. This method allows anetwork to grow from a simple to a complexstructure until it is capable of fulfilling itsintended function. The approach is somewhatanalogous to the growth of an embryo or theevolution of a fossil line through time, it istherefore sometimes referred to as anembryology or embryological algorithm. Thepaper begins with a general introduction,comparing this method to other competingtechniques such as The Genetic Algorithm, otherEvolutionary Algorithms and SimulatedAnnealing. A literature survey of previous workis included, followed by an extensive newframework for application of the technique.Finally, examples of applications and a generaldiscussion are presented.     

Introduction

The Internet is no longer ‘new technology’ to many charities, both in the UK and beyond. Some campaigning charities, members of the Association for Progressive Communications, have been using the Internet since the mid‐1980s to co‐ordinate activity internationally. For many international aid and development charities, e‐mail has long been a reliable method of communicating with partner organisations overseas in countries which have poor telecommunications infrastructures. Yet there remains considerable debate amongst UK charities about just what the Internet can offer. Many charities seem to believe that it will indeed offer opportunities and advantages, but that these will not become evident for a period of several years. Others are talcing a less conservative attitude and are deliberately testing the various opportunities they can see. This paper summarises UK charities’ efforts at using the Internet to raise funds. It explains the significance of the Internet to charities, arguing that charities should already have begun to test its use in some ways. It summarises the use of the Internet in the UK, demonstrating that it is a significant medium, used by many different people, that charities can no longer ignore. It lists the various methods of fundraising used by UK charities, and it looks at some of the threats that it represents to charities.     

Plant health and food security,linking science,economics, policy and industry

Protecting plant resources from harmful organisms that can spread internationally is a major challenge for plant protection organisations. Natural scientists and economists have methods that contribute to informing and supporting government decision makers in plant health authorities, who also need to account for stakeholders’ views when developing policy and regulations to mitigate plant pest risks. Increasingly plant protection authorities seek to develop integrated decision making through economists and scientists working within an interdisciplinary framework. In this special section of Food Security we introduce a series of papers presented at an international conference that brought together natural scientists, economists, industry representatives and plant health policy makers to report the state of the art and explore the direction and future research needs for such interdisciplinary working to deliver rational plant protection policy and improved food security for the 21st Century. The collection of papers combine contributions from leading academics and influential policy makers and provides cohesive international perspectives on the use of science and economics, as well as their integration, to progress the development of integrated multi-disciplinary plant health policy making around the world. Using a modified version of the world café method during a conference workshop activity, participants identified greater international co-operation as a key mechanism that would reduce international plant health risks. Specifically, co-operation over analysis among stakeholders and along supply chains were seen as key issues.