ABSTRACT Trichotillomania was first defined over a hundred years ago as a self inflicted alopecia resulting from avulsion of hair. Previous Positron Emission Tomography (PET) studies have shown increased count density in the right superior parietal region of patients suffering from trichotillomania. It is unclear if this increase in count density might be a state or trait related marker of the disease. Research has indicated that Cognitive Behaviour Therapy can systematically modify cerebral metabolic activity which is significantly related to clinical outcome. In the case of Obsessive Compulsive Disorder (OCD), a decrease of metabolic activity has been demonstrated using Pet. The present study was undertaken to investigate whether similar metabolic changes as indicated by Single Beam Positron Emission Computerised Tomography. (SPECT), will be found in trichotillomania after Cognitive Behaviour Therapy. Twelve patients diagnosed as suffering from trichotillomania, using DSM-IV criteria, underwent brain SPECT scanning using 99mTc-HMPAO. Scanning was performed before and after Cognitive Behaviour Therapy intervention. The psychotherapy was conducted in 12-16 sessions. The response to Cognitive Behaviour Therapy was assessed using the Psychiatric Institute Trichotillomania Scale and the Hamilton Anxiety Rating Scale. Ratings were completed at the beginning and end of the trial. The analysis of the scan data was done by comparing the left to the right superior parietal region. For each patient the region of interest was applied on the superior transaxial brain slices where the cingulate gyrus fully appeared. Each region of interest had the average number of counts normalised to the maximal cerebellar uptake. Baseline studies showed a significant increased count of 99mTc-HMPAO in the right superior parietal areas compared to the same areas on the left (p<0.0003). This pattern normalised after Cognitive Behaviour Therapy, such that there was no significant difference between the right and left superior parietal areas in those patients who responded (n=9) to therapy. In the non-responder group (n=3), the pattern remained unchanged. Using SPECT this study confirms previous reports of increased density in the right superior parietal lobe. In addition, it suggests that the increased count of 99mTc-HMPAO in the right parietal area is a state related disturbance in neurophysiology in this disorder, as it resolves with successful treatment. Of substantial importance is the fact that this study demonstrates a neurophysiological substrate and impact of psychotherapy. In conclusion this data suggests that the increased count density in the right superior parietal area is a state related marker of trichotillomania. 99mTc-HMPAO brain SPECT can therefore be used to monitor therapy of patients suffering from this disease.

MMed, Epidemiology and Biostatistics,University of the Witwatersrand, 2009 / Background: South Africa is one of the countries with the highest Human Immunodeficiency Virus (HIV) prevalence in the world. The main mode of transmission in South Africa is via heterosexual intercourse. Thus there is the need to identify factors associated with HIV high risk sexual behaviour to inform future intervention programmes. Objective: To determine the association between alcohol consumption and high risk sexual behaviour in South African adults in 2006. Methods: Secondary data analysis of cross sectional study involving 1544 adult males and females, between 16-65 years interviewed in the Soul City National Survey. A multi-stage, stratified and clustered probability sampling technique was used. Univariate and multivariate analysis was done using student t test, chi square test and logistic regression models. Results: The prevalence of alcohol consumption in the week prior to the survey was 24.4% (95%CI: 22.2-26.6). The prevalence of heavy episodic drinking in last one month was 17.5% (95%CI: 15.5-19.4). There was an association between broad socioeconomic conditions and sexual behaviour particularly age, sex and race (P<0.05). The mean age at sexual debut was 17.13 (SD 2.61) years in the males and 17.91 (2.45 SD) years in females (P<0.001). Of the sexually active respondents, 12.7% and 4.2% of the men and women respectively had multiple partners currently (P<0.001). Generally consistent condom use was more in men although, only 10.3% of the men and 5.6% of the women used the condoms consistently with their casual partners (P=0.28). Multivariate regression showed that alcohol use predicted having multiple partners (AOR 2.37; 95%CI 1.19-4.69 and AOR 4.15; 95%CI 1.37-11.97) for moderate and problem drinkers respectively. Also, heavy episodic drinking predicted having multiple partners by three times (AOR 3.21; 95%CI 1.69-6.39). There was a significant dose response relationship for having multiple partners (P<0.05). As regards unprotected sexual intercourse, although not significant, female drinkers were found to be protected from inconsistent condom use with a casual partner. Male drinkers on the other hand, were found to be at a higher risk of having unprotected sex with casual partners. Perceptions of susceptibility to HIV (AOR 0.31; 95%CI 0.17-0.56), and alcohol related harm (AOR 0.17; 95%CI; 0.22-0.71) influenced consistent condom use with casual partners. Also regards gender differences, women who drank alcohol (AOR 9.68; 95%CI 1.31-17.45 vs. 1.17; 0.28-4.89) or were heavy episodic drinkers (AOR 4.45; 95%CI 1.46-3.55 vs. 2.43; 1.03-5.92) had a higher probability of having multiple partners than men. Conclusion: There is a strong association between risky alcohol use and high risk sexual behaviours. HIV prevention programmes need to address reduction in alcohol intake and changes in drinking pattern. Further research to disentangle the relationship between condom use and alcohol use is needed.

MSc (Med) (Child Health Neurodevelopment), Faculty of Health Sciences, University of the Witwatersrand / Background Disruptive behaviour is the most commonly reported mental health problem in individuals with learning disability. Pharmacotherapy is part of a multidisciplinary approach to the treatment of disruptive behaviour. Risperidone, an atypical antipsychotic drug, is the most commonly used treatment for symptom improvement. It is therefore important to establish the efficacy and safety of risperidone therapy in this dependent, vulnerable and young population, given the well documented adverse effects and the potential for long term treatment. Objectives To assess the effects of risperidone for disruptive behaviour in children and adolescents with learning disability. Search strategy The following electronic databases were searched: CENTRAL (Cochrane Central Register of Controlled Trials); MEDLINE; PsycINFO; CINAHL; Clinicaltrials.gov; National Research Register (NRR). In addition, reference lists of relevant publications and narrative reviews were checked; handsearches were done; authors of published trials and pharmaceutical manufacturer of risperidone (Risperdal) were contacted. Selection criteria All randomised or quasi-randomised controlled trials of risperidone versus placebo (or no treatment) for children and adolescents (age less than 18 years) with a diagnosis of learning disability and disruptive behaviour were considered. Data collection and analysis Trial eligibility and data quality were evaluated and analysed by the author and independently verified by an additional reviewer. Unpublished data were considered for inclusion and relevant authors were contacted in the case of incomplete data. Results Four randomised controlled trials involving 279 children and adolescents were identified. The majority of the children were living at home and not institutionalised. Meta-analyses of the primary outcome scales (Nisonger Child Behaviour Rating Form, Aberrant Behaviour Checklist, Behaviour Problem Inventory) measuring several core symptoms of disruptive behaviour, namely conduct problems, self-injury, irritability, aggressive / destructive behaviours and stereotypy suggest statistically significant improvement in disruptive type behaviours in children treated with risperidone compared to placebo. Adverse event data showed that the prevalence of adverse effects viz. weight gain, sedation / somnolence and raised prolactin levels were significantly higher in the children receiving risperidone. Conclusions In the studies included in this review, risperidone treatment for disruptive behaviour in learning disabled children and adolescents appears to have a beneficial effect on certain symptoms of disruptive behaviour. However, the applicability of these findings to wider clinical practice remains unclear, due to poor methodological quality, inadequate study sample size and short duration of treatment of the included studies. Long term safety has not been established and serious adverse effects, affecting growth, are of concern. Further research is required to establish the efficacy and safety of risperidone for disruptive behaviour in learning disabled children and adolescents in clinical practice.

No description available.

In the analysis of movement patterns of animals, stochastic processes play an important role, providing us with a variety of tools to examine, model and simulate their behaviour. In this thesis we focus on the foraging of specific animals - bumblebees - and analyse experimental data to understand the influence of changes in the bumblebees’ environment on their search flights. Starting with a discussion of main classes of stochastic models useful for the description of foraging animals, we then look at a multitude of environmental factors influencing the dynamics of animals in their search for food. With this background we examine flight data of foraging bumblebees obtained from a laboratory experiment by stochastic analyses. The main point of interest of this analysis is the description, modelling and understanding of the data with respect to the influence of predatory threats on the bumblebee’s foraging search flights. After this detail-oriented view on interactions of bumblebees with food sources and predators in the experimental data, we develop a generalized reorientation model. By extracting the necessary information from the data, we arrive at a generalized correlated random walk foraging model for bumblebee flights, which we discuss and compare to the experimental data via simulations. We finish with a discussion of anomalous fluctuation relations and some results on spectral densities of autocorrelation functions. While this part is not directly related to the analysis of foraging, it concerns a closely related class of stochastic processes described by Langevin equations with non- trivial autocorrelation functions analyse experimental data to understand the influence of changes in the bumblebees’ environment on their search flights. Starting with a discussion of main classes of stochastic models useful for the description of foraging animals, we then look at a multitude of environmental factors influencing the dynamics of animals in their search for food. With this background we examine flight data of foraging bumblebees obtained from a laboratory experiment by stochastic analyses. The main point of interest of this analysis is the description, modelling and understanding of the data with respect to the influence of predatory threats on the bumblebee’s foraging search flights. After this detail-oriented view on interactions of bumblebees with food sources and predators in the experimental data, we develop a generalized reorientation model. By extracting the necessary information from the data, we arrive at a generalized correlated random walk foraging model for bumblebee flights, which we discuss and compare to the experimental data via simulations. We finish with a discussion of anomalous fluctuation relations and some results on spectral densities of autocorrelation functions. While this part is not directly related to the analysis of foraging, it concerns a closely related class of stochastic processes described by Langevin equations with nontrivial autocorrelation functions.

Similarities in brain size, life histories, psychology and behaviour in parrots, corvids and apes suggest that certain socio-ecological selection pressures may have driven the convergent evolution of cognition in these families. However, very little is known about parrot behaviour and cognition, outside of African greys and kea. Therefore, captive red-shouldered macaws (Diopsittaca nobilis) and black-headed caiques (Pionites melanocephala) were presented with a variety of tasks to assess their social and physical cognition and behavioural flexibility. Although these species possess many similarities in their life history and ecology, there are also substantial differences in their morphology and natural habitats that could have driven differences in their cognitive evolution. Observations of social and physical interactions in both species revealed that macaws engaged in high levels of affiliative behaviour, and object neophobia, whereas caiques displayed high levels of social play and object exploration. However, such differences did not appear to result in differences in their social or physical cognition. Macaws and caiques displayed comparable performances on Serial Reversal Learning tasks (as an index of behavioural flexibility). Both species also demonstrated similar performances on two Means-End transfer tasks and a series of innovative foraging tasks that were designed to assess their comprehension of object relationships. However, macaws and caiques appeared to solve such problems by generalising learned information across novel tasks. Overall, these findings suggest that these two species may approach certain socio-ecological problems using flexible cognition that may be generalised across different problems, supporting claims for a domain general intelligence.

The study examined the effects of lesions of the thalamic nucleus medialis dorsalis (MD) made by neurotoxin in three cohorts ofrats to help understand the contribution of this nucleus to learning and memory. The lesions typically provided comprehensive damage to . MD, while the use of an excitotoxin helped to minimise damage to fibres of passage or adjacent fibre tracts. This excluded one confounding influence that may have been present in some previous studies. Some MD lesions also affected the anterior thalamic nuclei, and this additional damage led to spatial memory impairments, helping to confirm the value of results from rats with lesions confined to MD. Whilst the groups with MD lesions were largely unimpaired on non-spatial tests of visual recognition and discrimination, they were impaired on a configural discrimination task. The MD lesions did not impair spatial nonmatching to sample in aT-maze, nor the acquisition or performance over delay conditions of the standard radial maze task. There were impairments, however, when the radial maze was rotated during the delay, requiring a strategy shift. Similar impairment was found when a matching, rather than non-matching, strategy was required on the T-maze task and also when only some arms were rewarded on the radial arm maze task for reference memory measurement. No impairment was seen when the T-maze matching task was reversed to the non-matching variant, emphasising the lesion rats' preference for preexisting rules. In addition, some evidence was found that MD lesions brought about increased activity, but had no effect on conditioned place preference. The study concludes that MD damage in rats does not directly cause memory deficits. The influence that MD damage has on memory is, however, similar to that associated with damage to prefrontal cortex causing deficits in rule-switching ability, a higher order frontal lobe function.

An independent groups comparative design was used to investigate mothers' attributions and affective-behavioural responses in relation to their pre-school child's problem behaviour. Mothers' beliefs about the age at which children develop aspects of social understanding and skills was also investigated. One group involved mothers whose pre-school child was identified as presenting with a behaviour problem, a second group involved' mothers of a 'non-problem' pre-school child. A premise of the research, however, was that all young children will at times present their parents with behaviour management problems. Participants were recruited from a number of sources, predominantly within community settings. Twenty-one participants were assigned to each group. The main findings were that groups differed significantly in terms of the extent to which participants believed their child had misbehaved in order to deliberately upset them, with problem group participants rating their child as having acted more intentionally. There was some evidence that groups also differed in relation to the extent to which they believed their cnild had control over the causes of their misbehaviour, with non-problem group participants rating their child as having more control. No group differences were found in terms of mothers' estimates of the age at which children develop a range of skills and understanding. Groups were also found to differ significantly in the number of child misbehaviour incidents they resolved and the type of behaviour response strategies used. Participants in the non-problem group were more likely to use 'co-operative' responses than those in the problem group. There was also a suggestion of some differences between groups in terms of reported affective responses to child misbehaviour. Results are discussed in relation to previous research and relevant theoretical literature. Implications for clinical practice and directions for future research are suggested.

Creativity is widely recognised as a vital element in modern-day engineering design. It is through creative behaviour that engineering designers produce creative solutions to their problems, and through creative solutions that many companies succeed. However, research into creative behaviour within engineering design has to date focused largely on the design process in general or on early-stage design; neglecting the often complex and constrained engineering practice that occurs during later design stages. It is to this research focus that the work presented here has been completed. Defined through its production of outputs that are original, of appropriate quality, and surprising, creative design behaviour is a culmination of several aspects within the engineering process; that of a person or team; working within a specific context; actively completing a process; that will produce an output for a particular design brief. At the centre of this situation is then the designer; it is through their individual behaviours that creative outputs are formed. Due to the nature of the later stage engineering design process, the accompanying influences under which designers work, and the types of activity that they complete, it presents a very different situation to early-stage design. It is therefore not possible to assume that understanding based on study of either early-stage design or the design process in general is entirely applicable to later-stage design processes or to the type of support that designers working within may need. Thus, when linked to creative behaviour, this presents an opportunity for research; there is possibility to gain valuable understanding of the manner in which creative solutions are produced through the study of designers’ creative behaviour in later-stage design. It is to this goal that this research has been performed, namely to characterise the creative behaviour of designers within the later-stages of the engineering design process. To this end, this thesis presents a detailed review of the field of creativity, the field of engineering design, and current understanding of designer behaviour. From the understanding that each of these provides, a framework and coding scheme are then developed, which are designed to identify creative behaviour within the individual tasks of designers throughout the design process. This coding scheme is then used within three studies; one based on seven less-experienced designers working within a 22-week project, one of eighteen designers of varying experience undertaking a design brief set by the author, and one of four designers working within industry. Through analysis of the data produced by these studies, this thesis contributes several characterisations of designer behaviour within later-stage design. These include typical task-types in which all designers are creative, two distinct creative approaches that correlate with a designers personal creative style, and types of tasks to complete in order encourage streamlining of the design process; in addition to more general characterisations concerning designer focus within early and late-stage design, and differences in behaviour between expert and less-experienced designers. Through the understanding that this research has gained and presents within this thesis there are many opportunities for further work on the subject of the improvement and support of designer behaviour. Both within an academic and industrial context, detailed and specific characterisation of creative behaviour in later-stage design has the potential to provide the means to improve both the process and output of engineering design.

For many years tax competition models and empirical analysis have been showing taxation as a key variable in FDI location decisions. Countries reduce taxation to attract firms in order to create employment and economic development. Firms locate their investments where the net return on capital is higher due to a lower tax burden. But tax competition is not optimal because the lowering of the tax burden causes an inefficient allocation of capital and provision of public goods. Thus, it requires coordination of tax policies in an economic area such as the European Union (EU). <br /> Despite data not showing a complete “race to the bottom” in tax rates, the predictions of the model are widely believed by businessman and the public opinion. But tax competition has been exclusively based on neoclassical theory where imperfect decisions by managers and certain features of the decision making process such as uncertainty are assumed to be not essential. The same applies when considering incompatibility with FDI theory. <br /> A complementary approach, based on the Heiner model, underlines the central role of uncertainty and the relevance of cognitive characteristics in managers´ FDI decisions. By applying an inductive and qualitative method through questionnaires, interviews with managers and statistical tests, the reliability of the behavioural model is confirmed. Furthermore, location decisions are shown to be significantly explained by heuristics and biases arising from the uncertainty faced by managers. <br /> But the role of taxation in these decisions appears less significant than is usually considered. From a sample of 112 Portuguese FDI operations only 4 are explained by fiscal variables. Then, if managers do not rely on taxation to decide the location of their firms´ investments abroad, countries should not emphasize this variable when implementing policies to attract FDI and the main argument for corporate tax integration in the EU vanishes.