Dortmund, Universiẗat, Diss., 2001.

Heidelberg, Universiẗat, Diss., 2001.

Heidelberg, Universiẗat, Diss., 2001.

Siegen, Universiẗat, Diss., 2001.

Proefschrift Erasmus Universiteit Rotterdam. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

No description available.

Background: Hepatitis B Virus (HBV) and Human Immunodeficiency Virus (HIV) co-infection in South Africa is estimated between 5-17%; however research determining this prevalence is lacking. With co-infection there is increased risk of liver cirrhosis, end stage liver disease, death as well as higher rates of chronic Hepatitis B infection. Chronic HBV develops in 20% of HIV positive individuals when compared to less than 5% in HIV negative individuals. This also further complicates Highly Active AntiRetroviral Treatment (HAART). Methods: A retrospective observational quantitative, cross-sectional, analytical study was done at the TC Newman Antiretroviral (ARV) centre in Paarl. All adult HIV positive patients that were started on antiretroviral therapy for the time period the new protocol was implemented were analyzed according to their Hepatitis B Antigen (HBsAg) result as well as for any association with gender, CD4 and age. The new protocol stated that all patients who were to start ARV’s had to be tested for Hepatitis B by testing their HBsAg. Results: A total of 498 participants were identified of which 40% were male and 60% were female. The HBsAg positivity rate was established at 7.6%. A higher prevalence was found among men as well as in the age group 50-59 years and those with a CD4 of 50/μL and less. Conclusions: With a prevalence of almost 8% there should definitely be a recommendation towards routine testing of HIV positive patients for Hepatitis B. If not before commencing ART then at least when switching from a regimen containing Lamivudine (3TC) or Tenofovir (TDF) to a regimen not containing these drugs in order to prevent acute flare ups of hepatitis.

The literature on the synthesis of tremorgenic indoles is reviewed in Chapter 1. These compounds are of great importance to agriculture, especially in New Zealand and the United States of America, as they affect the central nervous system of livestock grazing infected pastures. The research centres on the synthesis of lolitrem B, a ten ring structure containing a central indole moiety. The central indole moiety is common for all of the tremorgenic indoles. To this end, studies on the preparation of a trans-fused hydrindane system and its incorporation into the central indole moiety are discussed in Chapter 2. Chapter 3 details investigations into the preparation of a pyrrole from a model used for the hydrindane system. Once obtained, the pyrrole is modified to give the pyranopyrrole, which, in turn, is reacted with dienophiles in Diels-Alder cycloadditions to give substituted indoles. Utilising the model for the hydrindane, studies on the Fischer indole reaction were undertaken to give substituted indoles. Modification of these led to the synthesis of the left-hand side of paspalitrem B. This work is discussed in Chapter 4. Preparation of the tetrahydrofuran portion of lolitrem B and incorporation onto the central indole moiety is detailed in Chapters 3 and 4.

Age stereotypes are the different and often negative expectations and attitudes held by individuals about a given age group. Not only can age stereotyping lead to the unequal treatment of older people through differences in affective (age prejudice) and behavioural responses (age discrimination) toward them, but older people's own reactions to these stereotypes can have negative and damaging consequences. This thesis addresses the extent to which older adults' responses to negative age stereotypes impact on their performance on tests, and their health and well-being, further increasing age-based inequalities. Chapters 1 to 4, the introduction and theoretical chapters, introduce the thesis and the background for the subsequent studies. Areas reviewed include that of age stereotyping, how this may reflect negatively upon older adults' social identities, 'stereotype threat' as a specific response to this and evidence that perceiving ageism is associated with worse health and well-being in later life. Having identified research gaps, Chapter 5 then presents Study 1 (N = 105) which addresses the question of whether people are conscious of being judged negatively because of their age, what age stereotypes they are most conscious of and in what settings they believe they are applied. Findings confirmed that adults (particularly those aged 18-69) have a strong awareness of age-based judgement and that adults aged 60+ in particular are concerned about negative stereotypes of their competencies in a range of domains. Chapters 6 to 8 present studies 2, 3 and 4 which aimed to extend 'stereotype threat' research (Steele & Aronson, 1995). Stereotype threat theory posits that stigmatised individuals may fear confirming negative stereotypes about their social group. This negative experience ironically disrupts performance making it more likely that they act in line with negative stereotypes. Study 2, a meta-analysis including 82 effect sizes (N = 3882) split into multiple analyses, confirmed that age stereotypes have the potential to negatively impact older adults' memory and cognitive performance through age-based stereotype threat (ABST). Building on the findings from the meta-analysis, Study 3 experimentally tested whether uncertainty surrounding stereotype-based judgement explains why more subtle stereotype-based cues to stereotype threat have a greater impact on performance than fact-based cues, as was found in Study 2. Further, Study 4 examined whether the presence of a young observer or the giving of help to older participants might cue ABST and negatively impact maths performance. Although the hypotheses derived from stereotype threat theory were not supported by studies 3 and 4, these studies contribute to the stereotype threat literature by examining the potential everyday cues to ABST and the mechanisms through which it occurs. Finally, Chapter 9 presents Study 5 which uses survey data to examine different reactions-threat or challenge responses-to perceived ageism and whether these responses are associated with better or worse subjective health and well-being. Findings suggest that challenge responses may be a more adaptive reaction to ageism, with potential benefits for health and well-being in later life. Overall, the thesis highlights the damaging effects of older adults' threat responses to negative attitudes to ageing. Both negative societal attitudes and the way older people respond to and cope with negative stereotyping need to be addressed.

Gang membership is a global phenomenon and a problem affecting a multitude of official and unofficial agencies, often reported by the media and causing overwhelming financial strain, as well as increasing fear of crime in communities. Whilst research on gangs has enjoyed popularity for almost a century now, this was mostly based on a criminological perspective, which did not provide a holistic picture for practitioners. Specifically, little is known about the psychology of gang membership, as such research is still in its infancy. Moreover, calls for understanding the social psychological motives for gang membership - such as gang members' perceptions of group processes, and how these influence individuals - have been present for the last 50 years but development in the area has been limited. The aim of this thesis was to address some of this crucial gap in our knowledge of gang membership, to help enrich theoretical understanding, as well as prevention and rehabilitation strategies, so that these can be appropriately developed. In order for this to happen, it is key to understand which group processes lie behind gang membership based on gang members' subjective experiences, in different types of gang members, and how these relate to members' decisions to join and remain with a gang. The core assumption of gangs - that they are groups - has been largely neglected by research. The studies in this thesis provide the first holistic picture of the relevance of group processes in gang membership. The first, qualitative study, identified that group processes regularly manifesting in groups do, indeed, also manifest in gangs. It was also found that such group processes are understood by gang members in a manner specific to them. Further, the perceived group processes manifested differently at different stages of membership - when joining a gang and when remaining in a gang. The large quantitative studies that follow revealed that gangs differ from non-gang delinquent groups, and that different types of gang members differ in their perception of how group processes manifest. It was found that different types of groups and gangs were characterised by a specific set of perceived group processes. Further, these group process clusters differed, based on the stage of an individual's membership. This thesis therefore uncovered that the area of social cognition based on group processes is important. The main conclusions drawn from the studies presented in this PhD are: 1) Group processes manifest in gangs and are perceived in a specific manner. 2) The perception of group processes differ in gangs and other delinquent groups, and between different types of gang members. 3) There are specific clusters of perceived group processes which characterise specific types of groups and at different stages of membership - group processes should not be dealt with in isolation. 4) The findings show that how gang members perceive group processes should be a key consideration in future research and any intervention strategies designed for gang members.