Please read the abstract in the section 00front of this document / Dissertation (MSc (Chemical Pathology))--University of Pretoria, 2005. / Chemical Pathology / unrestricted

Endometrial carcinoma, which is preceded by non-malignant hyperplasia, is the fifth most common cancer in women worldwide. Various genetic alterations appear to be early events in the pathogenesis of endometrial cancer. The PTEN/MMAC1/TEP1 gene is most commonly mutated in endometrioid adenocarcinoma. This gene, on chromosome 10q23, codes for a tumour suppressor protein which displays lipid and dual-specific protein phosphatase activity. It has been implicated in several signal transduction pathways and seems to be involved in the negative regulation of the PI3K-, the MAPK- and the FAK pathways. Studies have shown that caucasian Americans have a 4-fold higher frequency of PTEN mutations than African Americans. An association of PTEN mutation status with clinical outcome has been found, where patients with PTEN mutation-positive endometrial carcinoma had a better prognosis than those without PTEN mutations. It has been hypothesized that the molecular pathogenesis of endometrial carcinoma within Caucasians and Black African groups may be different. The present study aimed to investigate the PTEN gene in caucasians and Black South African women with endometrial hyperplasia and carcinoma. The correlation between the frequency and type of mutations and the pathological features of the cancers (stage and grade) were also assessed. Paraffin¬embedded tissue samples from patients with endometrial hyperplasia [n=10] and cancer [n=47] were analysed for PTEN mutations using exon-by-exon PCR-SSCP. Thirty-two mutations were detected of which 24 were pathogenic (23 in the adenocarcinomas, one in the hyperplasias). These included 10 frameshift, 7 nonsense, 4 missense and 3 splice site mutations. Pathogenic mutations were located throughout the gene with the highest frequency observed in exon 5 (39.1%; 9/23), followed by exons 1 and 8 (both 17.4%; 4/23). This data does not differ significantly from published findings (P>0.05; x2-test). Pathogenic mutations were present in 54% (20/37) of the endometrioid adenocarcinomas and 10% (1/10) of the hyperplasias. No mutations were detected in the serous papillary cancers and poorly differentiated carcinomas. Fifty-five % (6/11) of tumours from Caucasians and 52% (13/25) of the tumours from Black South Africans had genetic alterations. When comparing the African and caucasian groups there were no significant differences with regards to PTEN mutation frequency (P>0.05; x2-test). Mutations occurred in early and advanced stage endometrial carcinomas, although the majority of the samples were stage 1 endometrioid adenocarcinomas. In the present study no association between the frequency of PTEN mutations and the grade and stage of the endometrial cancer were found (P>0.05; x2-test). To validate these observations, however, a larger sample size representative of all the grades and stages of endometrial carcinoma needs to be analyzed. / Dissertation (MSc (Human Genetics))--University of Pretoria, 2006. / Genetics / unrestricted

Colorectal cancer (CRC) is one of the most common forms of cancer in Western nations, it is however uncommon in sub-Saharan Africa. In South Africa there is an approximate ten-fold lower incidence of CRC in black patients compared to Caucasian patients. This could be due to differences in lifestyles and environment that exist between the various population groups. Underlying molecular events could also account for the difference in susceptibility to colorectal cancer. Mutations in the Peutz-Jeghers syndrome (PJS) gene, STK11, predispose to amongst others colorectal cancer. To examine the role of this gene in South African patients with CRC, DNA from 208 tumours (104 black patients, 104 Caucasian patients) was screened for STK11 mutations via PCR-SSCP analysis. In total 8 novel missense mutations, one of which was germline, were identified in seven tumours (~3.4% 7/208) from 5 black and two Caucasian patients. One tumour from a Caucasian patient was found to be a compound heterozygote. Peutz-Jeghers syndrome was thus diagnosed in 0.96% (1/104) of black patients via a germ line mutation. Thus 4.8% (5/104) of tumours from black patients and 1.9% (2/104) of tumours from Caucasian patients harbour STK11 missense mutations. In addition, 3 synonymous and 5 intronic mutations were detected in a further 73 tumours from black patients, whereas only 3 synonymous and 5 intronic mutations were detected in 25 tumours from Caucasian patients. The present study is the sixth to suggest that somatic mutation of the STK11 gene in sporadic colorectal cancer of Caucasians is an infrequent event. However, this is only the second study of a non-Western population to show somatic mutations in sporadic cases of CRC. Furthermore with regard to the anatomic site of tumours with somatic missense mutations, the present study found that for black patients 7.69% (2/26) of the left-sided tumours, 2% (1/50) of rectal tumours and 4.54% (1/22) of right-sided tumours harboured mutations. Thus the frequency of missense mutations of left-sided CRC tumours compared to right-sided tumours was not significantly elevated (÷2-test, 1df, p = 0.881) in the black population. This study represents the first investigation into the role of the STK11 gene in putative sporadic cases of CRC from both black and Caucasian South African patients. The observed mutations clearly show that mutations of the STK11 gene are infrequent in the CRCs of the South African Caucasian population, and more frequent in the South African black population. This may be a reflection of the differences in lifestyle and incidence of CRC in the different populations. / Dissertation (MSc (Human Genetics))--University of Pretoria, 2006. / Genetics / unrestricted

The present study experimentally examined the effect(s) of aversive racism on mock legal decisions made by university students. The experiment adopted a 3 (Evidence quality: low, ambiguous or high) x 2 (race stereotype crime: black vs. white) x 2 (Defendant race: black vs. white) between subjects design, in which 785 black, white, Indian and coloured participants were asked to judge legal cases. The legal vignettes were piloted to ensure that low, ambiguous and high evidence conditions were clearly represented, and that the white stereotype and black stereotype crimes chosen for the research were appropriate. Participants were each given two vignettes and used 10-point scales to judge a) the guilt or innocence of the defendant(s) and b) the sentence they would recommend for the defendant(s) should they be found guilty by a court of law. Our prediction that we would find evidence for the classic aversive racism effect in this sample was not supported, and no evidence of racial bias was found. Interestingly, white participants judged the guilt of defendants more leniently than all other race groups. These results are discussed and recommendations for future research are made. / Thesis (M.A.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

This thesis begins with the assumption that the theory of academic dependency provides an adequate framework within which the relationship between social science communities in the North and South can be understood. Present problems of social scientists in the South have very often been attributed to this dependence and it has been concluded that academic dependence has resulted in an uncritical and imitative approach to ideas and concepts from the West (Alatas, 2000). This dependence has also resulted in the general regression among social scientists based in the South and in a marginalisation of their works within the social science community no matter how significant and original they may be. The problematic invisibility of the works of prominent South African scholars is a dimension of a wider crisis of academic dependence, if unchecked this current trend will also reinforce academic dependence. From the nature of the problems generated by academic dependence, it is obvious that there is a need for an intellectual emancipation movement. This movement may take different forms that may range from but are not limited to a commitment to endogeneity which involves among other things, knowledge production that takes South African local conditions seriously enough to be the basis for the development of distinct conceptual ideas and theories. This requires transcending the tendency to use ‘the local’ primarily as a tool for data collection and theoretical framing done from the global north. Secondly, there is a need to take the local, indigenous, ontological narratives seriously enough to serve as source codes for works of distinct epistemological value and exemplary ideas within the global project of knowledge production. Endogeneity in the context of African knowledge production should also involve an intellectual standpoint derived from a rootedness in the African conditions; a centring of African ontological discourses and experiences as the basis of intellectual work (Adesina, 2008: 135). In this study, it is suggested that the recommendations highlighted above can only succeed if scholars make an effort to actually engage with locally produced knowledge. There is therefore a need to make greater efforts to know each other’s work on Africa. This demand is not to appease individual egos but it is essential for progress in scientific work. African communities will benefit from drawing with greater catholicity from the well–spring of knowledge about Africa generated by Africans. In the South African context, transcending academic dependence in the new generation of young academics requires engagement with the work of our local scholars who have devoted their lives to knowledge production. This thesis explores the scholarship of Professor Bernard Magubane by engaging with his works on race, class and inequality by locating his works within the wider debates on race, class and inequality in South Africa. The specific contributions of Professor Magubane to the enterprise of knowledge production are identified and discussed in relation to his critique of Western social science in its application to Africa. The making of Professor Magubane’s life, his career, scholarship and biography details are analysed with the intention of showing their influence on Magubane as a Scholar. The examination of Professor Magubane’s intellectual and biographical accounts help to explain the details, contexts and implications of his theoretical paradigm shifts. This helps prove that Professor Magubane’s experiences and theoretical positions were socially and historically constituted. The research from which this thesis derives is part of an NRF-funded project, on Endogeneity and Modern Sociology in South Africa, under the direction of Professor Jimi Adesina.

Thesis (MScSportSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The purpose of this qualitative-quantitative study was to describe the exercise intensity and predictors of performance of a multi-stage mountain bike (MTB) race (2014 Absa Cape Epic) lasting 8 days. Twenty-three amateur mountain bikers (age 39 ± 9 years, height 178.8 ± 8.2 cm, body mass 74.7 ± 9.1 kg, VO2max 54 ± 7 ml.kg-1.min-1) who completed the 2014 Absa Cape Epic were involved in the study. The participants were divided into two groups according to their MTB experience. The experienced group included participants who previously completed more than three 3-day multi-stage MTB events and the novices group included those who has completed less than 3-day multi-stage MTB events. Prior to the event the participants completed a maximal aerobic cycling test and a simulated 40 km time trial (TT). The maximal aerobic test was used to determine 3 work intensity zones based on heart rate (HR) corresponding to blood lactate thresholds (LT: increase in blood lactate concentration of 1 mmol.l-1 above baseline values and the onset of blood lactate accumulation (OBLA), a fixed blood lactate concentration of 4 mmol.l-1). There were no statistically significant differences in the physical, physiological and performance variables measured in the laboratory between the two groups. The exercise intensity during the Cape Epic was measured using telemetric HR monitoring sets. RPE values were noted after each stage of the race. The mean HR was 88.1 ± 5.3% (experienced) and 84.2 ± 11.0% (novices) of maximal HR during the race or 88.9 ± 3.5% (experienced) and 85.9 ± 10.6 (novices) of laboratory determined maximum HR. More time was spent in the “low” HR zone (43.1 % vs 58.5 %, respectively), while only a small amount of time was spent in the “hard” HR zone (7.4% and 6.1%, respectively). The experienced group spent statistically significantly more time in the “moderate” HR zone compared to the novices group (49.5 % vs. 35.4 %). The experienced group performed significantly better during the event compared to the novices group in both the total event time (P = 0.004) and the general classification (P = 0.01). Relative and absolute power output (PO) at OBLA (P = 0.01 and 0.02, respectively) were statistically significant predictors of total event time, while relative peak power output was a significant predictor of general classification for the event (P = 0.02) . The total TT time was a significant predictor of average event HR (P = 0.03). This study showed that this MTB stage race is physiologically very demanding and requires cyclists to have excellent endurance capacity, as well as strength and power. The parameters from the maximal aerobic capacity test correlated better with outdoor performance than parameters from the simulated 40 km TT. Therefore the standard maximal aerobic capacity test are sufficient for testing mountain bikers and sport scientists can continue using this test to prescribe exercise intensity zones for training and events. / AFRIKAANSE OPSOMMING: Die doel van hierdie kwalitatiewe-kwantitatiewe studie was om die oefeningsintensiteit en voorspellers van prestasie tydens ‘n multi-dag bergfiets kompetisie (Absa Cape Epic) van 8 dae lank te bepaal. Drie-en-twintig bergfietsryers (ouderdom 39 ± 9 jaar, lengte 178.8 ± 8.2 cm, liggaamsmassa 74.7 ± 9.1 kg, VO2maks 54 ± 7 ml.kg-1.min-1) wat die 2014 Absa Cape Epic voltooi het, het aan die studie deelgeneem. Die deelnemers is in twee groepe verdeel volgens hulle ervaring in multi-dag bergfiets kompetisies. Die ervare groep was al die deelnemers wat meer as drie 3-dae multi-dag bergfiets kompetisies voltooi het. Die onervare groep was al die deelnemers wat minder as drie 3-dag multi-dag bergfiets kompetisies voltooi het. Voor die kompetisie het al die deelnemers ‘n maksimale aërobiese toets en ‘n gesimuleerde 40 km tydtoets in die laboratorium voltooi. Die maksimale aërobiese toets is gebruik om drie werk intensiteit sones volgens die hartspoed te bepaal, naamlik die hartspoed by die laktaatdraaipunt(‘n toename in bloed [laktaat] van 1 mmol.l-1 bo die basislynwaardes) en die hartspoed by die aanvang van bloedlaktaat akkummulasie (‘n vaste bloed [laktaat] waarde van 4 mmol.l-1). Daar was geen statisties betekenisvolle verskille in die fisiese, fisiologiese en prestasie veranderlikes tussen die twee groepe nie. Die oefeningsintensiteit tydens die Cape Epic was gemeet deur gebruik te maak van hartspoedmonitors. Die RPE waardes was aan die einde van elke skof genoteer. Die gemiddelde hartspoed was 88.1 ± 5.3 % (ervare) en 84.2 ± 11.0 % (onervare) van maksimale kompetisie hartspoed, of 88.9 ± 3.5 % (ervare) en 85.9 ± 10.6 % (onervare) van die maksimale hartspoed soos in die laboratorium gemeet. Die fietsryers het meer tyd spandeer in die “lae” hartspoed sone (43.1 % vs 58.5 %, onderskeidelik), in vergelyking met die “moeilike” hartspoed sone (7.4 % vs 6.1 %, onderskeidelik). Die ervare groep het statisties betekenisvol meer tyd in die “matige” hartspoed sone spandeer (49.5 % vs. 35.4 %) in vergelyking met die onervere groep. Die ervare groep het beter presteer tydens die kompetisie vir beide totale kompetisie tyd (P = 0.004) en algehele klassifikasie (P = 0.01). Relatiewe en absolute krag by aanvang van bloed laktaat akkumulasie was statisties betekenisvolle voorspellers van totale kompetisie tyd (P = 0.01 en 0.02, onderskeidelik), terwyl maksimale krag ‘n statisties betekenisvolle voorspeller was van algehele klassifikasie in die kompetisie (P = 0.02). Die totale tydtoets tyd was ‘n statisties betekenisvolle voorspeller van gemiddelde hartspoed tydens die kompetisie. Die studie het gewys dat hierdie multi-dag bergfiets kompetisie fisiologies baie uitdagend is en dat fietsryers uistekende uithouvermoë kapasiteit, sowel as krag en plofkrag moet besit. Die veranderlikes van die maksimale aërobiese toets het beter met prestasie in die veld gekorreleer as die veranderlikes van die gesimuleerde 40 km tydtoets. Daar word dus afgelei dat die standaard maksimale aërobiese toets voldoende is vir die toetsing van bergfietsryers en sportwetenskaplikes kan aanhou om hierdie toets te gebruik om oefeningsintensiteit sones voor te skryf vir oefensessies en kompetisies.