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Many types of insect, in particular the nocturnal Lepidoptera, will fly towards artificial sources of illumination. Such animals are often described as being positively phototactic, but although little progress has been made towards a fundamental understanding of this phenomenon, its existence continues to be exploited with the use of light-traps. This thesis attempts to explain, in part, why certain British night-flying Lepidoptera are caught, or fly close to, light-traps. The experimentation and analysis has been structured into three separate but inter-related studies. The first is an investigation into the effects that weather factors exert on light-trap catch. Standard analytical procedures were extended to reveal that sensitivity to these factors is related to insect size and gross morphology. The second of these studies is an analysis of the types of moth flight pattern produced when these insects are exposed to various forms of illumination under field conditions. Moth tracks were recorded on video with the help of image intensification, and the frame-by-frame co-ordinates transferred to, and processed by, a microcomputer, which produced matrix maps of speeds, accelerations and time-surface densities around a light-trap. Instantaneous windspeeds were recorded. The dynamical analysis suggests that moth flight towards light arises primarily from a misinterpretation of the stimulus, competing at short distances with a strong escape response, thus evoking a profound state of disorientation. Furthermore, the data indicated that the types of pattern found were species linked. In the third study, a remotesensing technique was used to quantify moth aerial density, which was compared with simultaneous light-trap catches nearby, giving an estimate of absolute trap catching efficiency under various meteorological conditions. Because of their mode of operation, and their increasing loss of effectiveness in higher windspeeds, light-traps have only a limited capacity to reflect aerial density.

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This thesis examines the potential of the Social Representation (SR) approach as an alternative to the traditional social cognition approach adopted in the study of cancer-related thought and behaviour. The traditional approach is critically examined. The main motivation for this thesis concerned the non-compliance of cancer-related health behaviour despite the huge investment into health promotion campaigns. Given the lack of any methodological orthodoxy for the study of SRs the core aim of the thesis was to explore the methodology appropriate for SR analysis in the area of cancer. In recognition of the complex nature of SRs a multi-method approach was adopted in which four different methods were evaluated. As the basis of this research Qualitative methods (Chapter 4) were used to explore the underlying rationale of the representations of cancer, and to inform the design of more quantitative instruments. Next an idiographic approach (Multiple Card Sort Procedure) (Chapter 5) was employed to examine the cognitive component of the SRs of cancer. The affective elements making up the SRs of cancer along with the cultural elements were then explored using a Metaphor Procedure (Chapter 6). The fourth method, a self-report Questionnaire (Chapter 7) was used to examine the attitudes, knowledge and emotional cognitions making up the SRs of cancer. An attempt was also made to identify shared representations using each of the methods employed using analytic procedures consistent with the data collected. Thus a qualitative analysis was carried out on the qualitative data, a scaling analysis on the idiographic data. Both the metaphor and the questionnaire data were analysed using a cluster analytic methodology (Fife-Schaw, 1993). Each method proved to have strengths and weaknesses. The questionnaire approach for example proved to be the most useful in examining the relationship between the representations of cancer and health behaviour, but the constraints of this method were shown by the idiographic technique. This work provided a foundation for the second part of the thesis. Using a questionnaire format (Chapter 8) the measurement tool for the SRs of cancer was refined on a sample of 510 respondents. Five factors were identified, IIInesslRestriction, Challenge, Symptom Focus, Cancer Control and Emotional Aspects. When operationalised into scales these factors proved to be highly reliable with values in excess of 0.75 making them sound measurement tools. Using a cluster - discriminant technique three shared representations of cancer were identified, an Ambivalent representation, a Positive Control representation and an Illness representation which proved to be differentially related to health behaviour. The positive orientation is an interesting one because it receives less documentation within the cancer literature. The research suggests that social cognition models are failing to fully account for the variance in health behaviour for a number of reasons. Perhaps most important is the insufficient attention paid to emotionally arousing qualities of cancer and the role played by socio-cultural factors. Lifestyle approaches, experience of cancer, and dominant conceptualisations in the media seem to be influencing the representations of cancer held. The role of individual differences within the formulation of SRs was then examined (see Chapter 8). The findings suggest that SRs are a product of both the social environment and individual psychological differences. Cancer-related thought and behaviour then may vary according to the social context as well as individual traits. The implication for health educators is that they cannot rely upon a superordinate representational 'norm' but must look at the mores and mileu of the target group in question.

The alms of the current study were, firstly, to examme factors predicting nurses' perception of risk of HIV contagion at work; and secondly to investigate nurses' compliance with universal precautions, and the reasons for their compliance and noncompliance. The research was carried out in three phases. Phase I of the research used the Yates and Stone (1992) model of risk as a theoretical framework with which to examine perceived risk and also investigated reasons for non-compliance. The results suggested that perceived risk was related to fear of contagion and knowledge of non-transmission modes. Additionally four factors were produced from the investigation of reasons for non-compliance. Phase 2 utilised a qualitative analysis of semi-structured interviews designed to yield salient beliefs and issues relating to: risk perception and fear of contagion; knowledge of HIV; precautionary compliance; and the use of social comparisons when evaluating risk. The third phase of the research project was designed to combine the results of the first two phases of research with established theory in order to investigate the two main aims of the study. The Yates and Stone model of risk was again used. The Theory of Planned Behaviour (Ajzen, 1986) was used as a framework with which to examine compliance with universal precautions, and the False Consensus Effect (Ross, House and Green, 1977) was also used to examine behaviours and beliefs relating to both risk perception and precaution use. As with phase 1 this phase was questionnaire based. The relationships between descriptor and outcome variables were examined through the use of univariate, bivariate and multivariate statistical techniques. Overall it was found that fear of contagion, knowledge of HIV, previous exposure to HIV, and perceived behavioural control were all significant predictors of perceived risk of HIV contagion, results which support the Yates and Stone conceptualisation of risk. Four factors relating to precaution non-use were found and the Theory of Planned Behaviour was found to predict and explain precaution non-use accurately for 71 % of participants. Relationships amongst the variables were investigated in detail and the results were discussed in tenns of both theoretical and practical outcomes.

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