Biomedical subjects

Gordon Mitchell

Publications and source records attributed to Gordon Mitchell.

4 recordsLinked to original sources

PubMed2006

Perceptual grouping in disorganized schizophrenia.

This study evaluated visual perceptual grouping in schizophrenia to test the hypothesis that the disorganization syndrome in schizophrenia is related to a deficit in cognitive coordination. Perceptual grouping was examined with three psychophysically well-controlled tasks in patients with disorganized schizophrenia (n=11), non-disorganized schizophrenia (n=24), psychotic disorders other than schizophrenia (n=31) and non-psychotic psychiatric disorders (n=35). These measures assessed processing of both concurrent and preceding stimulus context. Deficits in perceptual grouping were observed on all three tasks in disorganized schizophrenia patients. Dysfunctional perceptual grouping mechanisms produced both enhanced and impaired task performance suggesting that the pattern of performance observed was the result of a specific deficit in the grouping of stimulus elements. We interpret these data as further support for the hypothesis that the disorganization syndrome in schizophrenia reflects a widespread deficit in the cognitive coordination of contextually related stimuli, leading to dysfunctional grouping of stimulus features in vision, thought and language.

Adult↗

PubMed2005

Forecasting environmental equity: air quality responses to road user charging in Leeds, UK.

Sustainable development requires that the goals of economic development, environmental protection and social justice are considered collectively when formulating development strategies. In the context of planning sustainable transport systems, trade-offs between the economy and the environment, and between the economy and social justice have received considerable attention. In contrast, much less attention has been paid to environmental equity, the trade-off between environmental and social justice goals, a significant omission given the growing attention to environmental justice by policy makers in the EU and elsewhere. In many countries, considerable effort has been made to develop clean transport systems by using, for example, technical, economic and planning instruments. However, little effort has been made to understand the distributive and environmental justice implications of these measures. This paper investigates the relationship between urban air quality (as NO2) and social deprivation for the city of Leeds, UK. Through application of a series of linked dynamic models of traffic simulation and assignment, vehicle emission, and pollutant dispersion, the environmental equity implications of a series of urban transport strategies, including road user cordon and distance-based charging, road network development, and emission control are assessed. Results indicate a significant degree of environmental inequity exists in Leeds. Analysis of the transport strategies indicates that this inequity will be reduced through natural fleet renewal, and, perhaps contrary to expectations, road user charging is also capable of promoting environmental equity. The environmental equity response is, however, sensitive to road pricing scheme design.

Air Pollution↗

PubMed2005

Mapping hazard from urban non-point pollution: a screening model to support sustainable urban drainage planning.

Non-point sources of pollution are difficult to identify and control, and are one of the main reasons that urban rivers fail to reach the water quality objectives set for them. Whilst sustainable drainage systems (SuDS) are available to help combat this diffuse pollution, they are mostly installed in areas of new urban development. However, SuDS must also be installed in existing built areas if diffuse loadings are to be reduced. Advice on where best to locate SuDS within existing built areas is limited, hence a semi-distributed stochastic GIS-model was developed to map small-area basin-wide loadings of 18 key stormwater pollutants. Load maps are combined with information on surface water quality objectives to permit mapping of diffuse pollution hazard to beneficial uses of receiving waters. The model thus aids SuDS planning and strategic management of urban diffuse pollution. The identification of diffuse emission 'hot spots' within a water quality objectives framework is consistent with the 'combined' (risk assessment) approach to pollution control advocated by the EU Water Framework Directive.

Cities↗

PubMed2004

Concept mapping in pulmonary physiology using pathfinder scaling.

This three-part article begins with a brief presentation of a framework that describes different approaches to conduct and report research on expert knowledge. The framework contrasts direct vs. indirect approaches and provides examples of each. Second, the article gives a detailed description of the methods and results of three concept mapping studies in pulmonary physiology that employ Pathfinder scaling, an indirect approach. The studies derive concepts maps for a variety of faculty experts individually and in groups. Two of the studies focus on changes in students' concept maps of the pulmonary physiology concepts as a result of instruction. Changes are gauged in terms of the degree to which students' concept maps approximate instructors' concept maps due to educational interventions. An index of student-instructor concept map similarity is also correlated with student performance on final examinations. The article concludes by articulating several "next steps" in the Feinberg Northwestern and Wisconsin program of health sciences education research on concept mapping using Pathfinder scaling.

Adult↗