Ph.D. (Biochemistry) / Genetically modified (GM) crops were first introduced in the 1980s for the production of medicinal products. Since then, areas designated to GM crops have expanded drastically, with the GM crops grown to enhance agricultural productivity, improve agricultural practices, and as a tool to address potential pressures that will be faced by the agricultural sector and to address the issue of food security. Currently, cultivated GM crops include cotton, maize, rapeseed and soybean, carrying agronomic traits such as herbicide tolerance and insect resistance. Following the genetic modification of crops, three possible outcomes can be anticipated: these outcomes include the GM crop produced being equivalent to its untransformed counterpart, the GM crop differing from its untransformed counterpart with several well-defined characteristics, and the GM crop differing from its untransformed counterpart with a multitude of complex characteristics. In cases where the GM crop is equivalent to the untransformed counterpart, no further testing is needed. In instances where several well-defined and characterised differences are found between the GM crop and the untransformed counterpart, safety assessments are performed targeting these differences. The assessments will determine the impact of these unintended and unexpected alterations of the intended enhancement of the GM crops. However, methods currently used to assess GM crops have been found to be lacking, since they only focus on environmental and product-specific risks. Further evidence is essential, as part of GM crop safety assessment, on the molecular characterisation of these crops. This evidence is based on the potential impact of the transformation event, integration of the transgene into the host plant, as well as unintended alterations such as altered gene expression that may occur to the host plant. These events may assist in the further detection of potential dangers of the GM crop. As a result of these highlighted gaps, a project was formulated to study the unintended genomic alterations that may occur during and following the production of a transgenic plant...

M.Cur. / HIV and AIDS education as a prevention strategy is priority number one in the National Strategic Plan for South Africa. Prevention of illnesses is also an integral part of primary health care (Department of Health, 2007: 10). There are different role players offering age-appropriate HIV and AIDS education to primary school learners, such as educators (within the Life Orientation programme), school health nurses (as part of health promotion) and non-governmental organisation (NGO) peer educators who visit schools per invitation or as part of their programme. Knowledge of collaboration amongst different role payers is necessary in order to pool the complementary strengths and maximise the positive impact of education on adolescents’ sexual behaviour. The design used in this research is quantitative and descriptive in nature. The respondents were clustered according to categories, namely school health nurses, primary school educators and NGO peer educators. As school health nurses (n=8) and peer educators (n=15) constituted a small population, they were all included in the study. Systematic random sampling was used to select respondents from the population of educators (N=75: n=42). A developed questionnaire was distributed to the consenting respondents who met the inclusion criteria. A checklist was also developed to review policies and guidelines used as a framework for providing HIV and AIDS education to learners by role players. A pilot study was conducted. The Statistical Package for Social Science (SPSS14.0) for Windows was used to analyse the data.

The present study sought to investigate the effects of a Standard workstation, designed for “average” users, on an anthropometrically diverse sample of computer operators, and to assess whether physical and perceptual responses, as well as performance efficiency were dependent on stature. Further investigation assessed the influence of personalised adjustments to the Standard workstation, based on the anthropometric characteristics of the subjects, as well as the introduction of a custom-designed ‘floating’ wrist support, on subject responses. All subjects (n=30) were tested in each of the three workstations: Standard, Personalised and Wrist Support. For analysis of responses in the Standard workstation, subjects were divided into three groups depending on their stature: Short (<1650mm), Medium (1650mm to 1800mm), Tall (>1800mm). The musculoskeletal responses indicated that Tall subjects were forced to adopt the most awkward general body postures as a result of the low computer screen. However, the low screen allowed for the Short subjects to adopt the most natural general body postures, although levels of muscular activity in the upper trapezius suggest that the muscular load imposed on both Short and Tall subjects was significantly greater than that imposed on the Medium subjects. In addition, the Medium subjects’ perceptions of the Standard workstation dimensions support the fact that this workstation was better suited to users with “average” morphologies. The responses elicited in the Personalised and Wrist Support workstations were improved significantly when compared to the Standard workstation. Joint angles were more natural, upper trapezius EMG was reduced, standard of performance improved and perceptual responses indicated a diminished incidence of body and visual discomfort, as well as greater perceived satisfaction with these workstation dimensions. The improved physical responses suggest a decrease in the risk of developing cumulative trauma disorders. Although subjects were unaccustomed to the wrist support device, this workstation demonstrated a further reduction in the range of wrist angles, as well as a general positive attitude towards the concept.

The HIV and AIDS epidemic continues to affect communities worldwide particularly so in South Africa. Youth, also the so-called Coloured youth, continue to remain at risk of infection, in spite of having been exposed to information about HIV and AIDS. This study explores the views of Coloured secondary school youth in a rural town in the Eastern Cape, on HIV and AIDS. Fifteen secondary school learners, both boys and girls, from Grades 10 to 12 were purposively selected. This qualitative study, framed within an interpretivist paradigm, draws on a phenomenological methodology. The data was generated from using drawing and focus group interviews and analysed using thematic analysis. The research adhered to ethical principles and trustworthiness was ensured. Constructivism and Bronfenbrenner’s bio-ecological systems theory were used to frame the study and to make meaning of the findings. In response to the primary research question, What views do Coloured youth attending a secondary school in a rural town have of HIV and AIDS?, five themes emerged, namely: individuals spread HIV, impoverished family life increases youth vulnerability to HIV, youth under pressure from peers knowingly engage in risky behaviour, misconceptions fuel the epidemic, and HIV and AIDS “captures the community in its net”. Drawing on the findings and in response to the secondary research question, What guidelines can be developed to assist educators to facilitate learners taking action against the spread of HIV and AIDS?, several guidelines were developed. They suggest that teachers should use participatory pedagogies to engage secondary school learners when teaching HIV and AIDS, build self-esteem in their learners, assist learners in dealing with peer pressure, engage learners in erasing misconceptions, and enable learners to break free from being “caught in the net” of HIV and AIDS. Collectively these guidelines could enable learners to take action in protecting themselves and their community against the spread of the HI virus. The study concludes that the views that Coloured secondary school learners from a rural town have about HIV and AIDS show their awareness of the realities of the epidemic affecting the individual, the family, the school and their community. They have constructed their views of HIV and AIDS in a way which shows their understanding of the complexities of the epidemic.

Positive psychology has led a movement that concentrates on positive characteristics. The current study examined the relationship between positive emotions, negative emotions, flourishing, languishing, and cardiovascular functioning. The study uses guided imagery to help participants recall a negative emotional event and positive emotional event in a counterbalanced order. The reverse order allowed us to examine the differential contributions of stress buffering versus facilitated recovery effects to higher levels of heart rate variability (HRV). The study also examined the relationship between mental health categories and known cardiovascular disease risk. Univariate analysis of variance revealed that positive emotions can serve as a stress buffer and dampen cardiovascular responses to a negative event. Also, analysis revealed a trend for the prediction that positive emotions can facilitate cardiovascular recovery following a negative event. Exploratory analysis did not reveal differences between a facilitated recovery group and a buffering group for cardiovascular measures. Future studies should include tighter control to help compare the differential influences of stress facilitation and stress buffering on cardiovascular functioning. The results from the study indicate that it is still too early to tell whether mental health buffers those individuals from developing CVD, and to answer whether languishing increases the risk of CVD. Longitudinal studies of young individuals without a prior history of any risk of CVD and who are flourishing or languishing might help provide answers to these questions.

No description available.

The experiments reported in this dissertation explored the effects of selection for antibody response on other immunological measures and on production traits. The role of thyroid hormones in antibody response was also studied. Selection for high (HA) and low (LA) antibody response to sheep erythrocytes altered subclasses of antibodies in different ways. In line LA antibody response was primarily mercaptoethanol-susceptible (IgM), while the line HA response was primarily mercaptoethanol-resistant antibody (IgG). Sublines of HA and LA were developed with all possible combinations of major histocompatibility complex haplotypes B¹³ and B²¹. An experiment was conducted to test Marek’s disease resistance of these haplotypes in line LA. Mortality from a natural exposure was high for all three groups, and there was no difference among haplotypes. Correlated responses of growth and reproductive traits in lines HA and LA were due to genetic correlations with antibody response. These genetic correlations were generally negative and are suggestive of differential allocation of resources. Phenotypic correlations were generally very small. Changes in allelic frequencies at alloantigen systems were also observed in response to selection. Experiments designed to study the role of thyroid hormones on antibody responses showed no direct relationship. Chickens from lines HA and LA fed thiouracil exhibited hypothyroidism but did not differ from controls in antibody response. Differences in thyroid hormone concentrations between lines of dwarf and non-dwarf White Rocks selected for high and low juvenile body weight bore no relationship to differences in antibody responses. / Ph. D.

So, Chun Lung. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 178-196). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese; appendix in Chinese.

Thesis (MCur)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Parents and/or caregivers all over the world are expected to comply with existing childhood immunisation programmes in order to prevent outbreaks of preventable childhood diseases. The most important justification for this study was the 2010 measles outbreak in the Western Cape province of South Africa. This outbreak correlated with the study conclusions of Corrigall, Coetzee and Cameron (2008:41) as they found the immunisation coverage in the Western Cape to be insufficient to prevent outbreaks of preventable childhood diseases. From the literature, it seemed that attitudes and factors that influence parent and/or caregiver compliance with the routine childhood immunisation schedule in the Witzenberg sub-district of the Western Cape persist. In doing this study, the researcher’s purpose was to discover what those factors were. The aim was to determine, understand and describe the attitudes and factors influencing parent and/or caregiver compliance with the routine childhood immunisation schedule, and the nature thereof. The set objectives were to gain knowledge of and insight into the factors influencing participants’ adherence with routine childhood immunisation; and participants’ feelings, attitudes, and experiences surrounding immunisation within the context of their health care environment. A quantitative research approach, with a smaller qualitative component, was selected for this study which had an exploratory descriptive design. The population targeted for data collection included parents and/or caregivers of children aged 0 to 60 months in the Witzenberg sub-district (N=8374), as well as in community health centres (CHCs) that provided immunisation and/or other primary health care services in the mentioned subdistrict (N=16). The non-probability convenience sampling of parents and/or caregivers consisted of 376 participants (n=376), while 8 CHCs (n=8) were selected through systematic sampling. The measuring instrument used as the data collection technique for this study was a selfadministered questionnaire. A pilot study was conducted to pre-test the questionnaire, and its reliability and validity were further ensured by submitting it for review to research experts in methodology and nursing. A combination of quantitative and qualitative methods was used to analyse the study data. MS Excel was used to capture the quantitative data after which it was analysed using descriptive statistics by means of STATISTICA version 9-software. Tesch’s approach to qualitative data analysis was used as a guideline with the purpose of identifying and categorising the essential qualitative data and grouping it together in one descriptive framework. The main findings were that parents and/or caregivers involved in this study were positive about immunisation and their experiences within the health service environment. They also felt that health workers were playing an important role in their decision-making process. However, their knowledge regarding the purpose of and contra-indications for immunisation were insufficient, and most parents reported that their children experienced side effects after immunisation. Key recommendations on conclusion of the study include clear, accurate and specific information to parents about the purpose of immunisation and its contra-indications and side effects. Vaccinators and managers should be informed about the persistent problem with mild vaccination side effects and refresher courses should be provided with regard to infection control, administration techniques and the reporting of adverse effects. / AFRIKAANSE OPSOMMING: Daar word van ouers en/of versorgers oor die wêreld verwag om aan bestaande kinderimmunisasieprogramme te voldoen ter voorkoming van vaksien-voorkombare siektes. Die belangrikste regverdiging vir die studie was die masel-uitbreking in die Wes-Kaapprovinsie van Suid-Afrika in 2010. Die uitbraak het die studiebevindinge ondersteun van Corrigall, Coetzee en Cameron (2008:41), wat bevind het dat immunisasiedekking in die Wes-Kaap onvoldoende was om ʼn uitbreking van voorkombare kindersiektes te verhoed. Volgens die literatuur het dit voorgekom asof die gesindhede en faktore wat ouers en/of versorgers se houding jeens die roetine- kinder-immunisasieskedule in die Witzenberg sub-distrik van die Wes-Kaap beïnvloed, voortduur. Die navorser het met hierdie studie ten doel gehad om die faktore te ontdek, ten einde die gesindhede en faktore wat ‘n invloed uitoefen te bepaal, te verstaan en te omskryf. Die doelwitte was om kennis in te win oor en insig te verkry in die faktore wat ouers en/of versorgers se aanhanklikheid met routine kinder immunisering beinbloed; en in ouers en/of versorgers se gevoelens, houdings en ondervindings ten opsigte van immunisasie in hulle gesondheidsorg-omgewing. ‘n Kwantitatiewe navorsingsbenadering met ‘n kleiner kwalitatiewe komponent is geselekteer vir die studie wat ‘n ondersoekend-beskrywende navorsingsontwerp gehad het. Die populasie wat geteiken is vir data-insameling was ouers en/of versorgers van kinders van 0 tot 60 maande in die Witzenberg sub-distrik (N=8374), asook gemeenskapsgesondheidsentrums wat immunisasie en/of ander primêre gesondheidsorgdienste in die genoemde sub-distrik aanbied (N=16). Die nie-waarskynlike gerieflikheidsteekproef van ouers en/of versorgers het uit 376 deelnemers (n=376) bestaan, terwyl 8 (n=8) gemeenskapsgesondheidsentrums deur middel van sistematiese steekproefbepaling geselekteer is. Die meetinstrument vir data-insameling in die studie was self-geadministreerde vraelyste. ‘n Loodsstudie is uitgevoer as vooraf-toetsing van die vraelys en die geldigheid en betroubaarheid daarvan is verder verseker deur die vraelys aan navorsingskenners in navorsingsmetodologie en verpleging te onderwerp. ‘n Kombinasie van kwantitatiewe en kwalitatiewe metodes is gebruik vir die analisering van die studie-data. Die kwantitatiewe data is op MS Excel ingevoer waarna beskrywende statistieke deur middel van Statistica weergawe 9-sagteware gebruik is om dit te analiseer. Tesch se benadering tot kwalitatiewe data-analise is as riglyn gebruik met die doel om belangrike data te identifiseer, te kategoriseer en in ‘n beskrywende raamwerk te groepeer. In die studie is daar hoofsaaklik bevind dat ouers en/of versorgers positief is oor immunisasie en hul ondervinding binne die gesondheidsorgomgewing, en dat gesondheidswerkers ʼn belangrike rol in hul besluitnemingsproses speel. Hul kennis aangaande die doel van en kontra-indikasies vir immunisasie was egter onvoldoende en die meeste ouers en/of versorgers het gerapporteer dat hul kinders ná immunisasie probleme met newe-effekte ondervind het. Die hoofaanbevelings wat uit die studie voortgespruit het, was dat duidelike, akkurate en spesifieke inligting aan ouers en/of versorgers verskaf moet word aangaande die doel van immunisasie en die kontra-indikasies daarvoor. Immuniseerders en bestuurders moet ook ingelig word oor die voortdurende voorkoms van newe-effekte sodat opknappingskursusse oor infeksiebeheer, korrekte toedieningstegnieke en die rapportering van newe-effekte aangebied kan word.

Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2018. / Ticks and tick-borne diseases are important limiting factors to the attainment of sustainable animal and human health, affecting livelihood of resource poor farming communities in developing countries. Rhipicephalus appendiculatus and Amblyomma variegatum (Ixodidae) are among the most troubling tick species in Africa. While ticks can be controlled by applying chemical acaricides, these chemicals are quite expensive, especially, for small-scale famers in developing countries. Hence, the quest for alternative tick control over the years have revealed that entomopathogenic fungi (EPF) and plant extracts have huge prospects as sustainable alternatives for tick control. Beauveria bassiana (Hypocreales) is a fungal entomopathogen with the ability to colonize plants endophytically and induce secondary metabolite production in plants, and it has been found to be a potential biological control agent against a wide range of arthropods. Several plant species including plant species belonging to the family Alliaceae possess anti-tick activities (repellent and toxic); therefore, integrating the two strategies by inoculating Tulbaghia violacea with B. bassiana could enhance secondary metabolite contents in extracts obtained from the plant and increase medicinal materials. The primary purpose of the present study was to evaluate the effect of indigenous endophytic entomopathogens inoculation of T. violacea on the plant growth, tissue nutrient contents and secondary metabolites, and anti-tick activities of extracts of T. violacea. The specific objectives were: (i) to carry out a study on the effects of inoculating T. violacea with fungal strains of B. bassiana and Clonostachys rosea on plant growth and tissue nutrient contents in extracts of T. violacea with the view of selecting one of the two fungi for further investigation (ii) to compare secondary metabolite profiles of extracts obtained from plants exposed to fungus (EPF) inoculum and control treatment during cultivation, and (iii) to determine whether exposure of T. violacea to an endophytic fungus (B. bassiana) during cultivation affects the repellent and acaricidal activities of extracts of T. violacea on A. variegatum and R. appendiculatus. The study had two experiments, presented in chapters two and three. In the first experiment, eight weeks old potted seedlings of T. violacea were inoculated separately with B. bassiana (strain SM3) and C. rosea (strain SM8) conidia suspended at concentrations of 1 x 106 conidia mL-1. Plant growth parameters, such as number of leaves, plant height (aerial part), fresh weights of aerial parts, and tissue nutrient contents were assessed. Results indicated that B. bassiana induced higher growth of plants than C. rosea. Inoculation with B. bassiana did not significantly (P ˃ 0.05) influence most of the growth parameters, number of leaves, fresht weight of roots and of fresh weight aerial parts (leaves) of T. violacea assessed in the current study. However, mean plant heights and root lengths were significantly (P < 0.05) higher in favour of B. bassiana treated plants compared to those in C. rosea. Fe contents in the roots (1416.3 ± 305.10 mg/kg) were found to be positively influenced (P < 0.05) by the fungal inoculation. There was a significant difference in roots (P < 0.05) on the uptake of Mn in C. rosea treated plants (243 ± 19 mg/kg) compared to the control group (169 ± 16.37 mg/kg) and B. bassiana treated roots (161.3 ± 14.44 mg/kg). Macro nutrients up take did not differ significantly among treatments on both leaves and roots (P > 0.05).