My research questions pertain to (1) how Black undergraduate studentsâwho were interested in STEM at college entranceâperceive influences on their choice of a STEM or non-STEM major and (2) to how studentsâ lived experiences in STEM appear to have challenged their success in their intended postsecondary STEM pathways. In exploring the answers to these questions, I focused on students in two different contextsâa historically Black college (HBCU) and a predominantly White institution (PWI). In addition, I traced out the racialized nature of studentsâ experiences and uncovered ways that STEM structures (e.g., instructional practices) seemed to be impacting their academic choice processes. Using qualitative interview methodology, I uncovered several findings. STEM structures formed barriers to the expression of certain studentsâ values that, in turn, dissuaded them from persisting in STEM. Introductory course expectations appeared to reify racialized inequalities in pre-college educational access. Some studentsâ lack of access to effective college STEM supports in the areas of instruction and academic advising was compounded by unequal access to compensatory, informal, STEM supports which were dispensed along racial lines. Microaggressions in STEM spaces were evident on both PWI and HBCU campuses, though HBCU students more frequently revealed how their STEM professors at times marginalized them because of their gender, nationality, and assumed class identities. Based on these findings, I offer a series of recommendations for how undergraduate STEM programs might be more supportive of equity and diversity with respect to Black undergraduate students.

The purpose of this research was to study the relationship between diversity climate perceptions and turnover intention among knowledge workers in the South African nuclear industry. The researcher hypothesised that race will moderate the above-mentioned relationship (Hypothesis 1), and organisational commitment will mediate the same relationship (Hypothesis 2). The research problem was a challenge seemingly facing South African businesses regarding Black knowledge worker retention. The research was a quantitative, cross-sectional study, and was a replication of a study conducted in the United States of America (USA). Data was collected by means of a questionnaire, which was e-mailed to subjects selected randomly from strata of Black and White knowledge workers. In total, 128 questionnaires were e-mailed to subjects, out of a population of 143. Multiple regression methods for testing moderator and mediator effects were used to test the hypotheses. The response rate was 56% (N=72). From the data collected, there was sufficient evidence in support of hypothesis 1. The null hypothesis was therefore rejected. Data collected did not support hypothesis 2 for the two race groups analysed together. However, when race was controlled for, mediation of the above-mentioned relationship was found among Whites. There was no evidence for mediation among Blacks. Copyright / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

The aim of this research was to determine whether or not if levels of employee engagement is affected by their organisation’s diversity targeting programs, and whether this could be a possible reason for the perceived high turnover of certain classes of employees. The research was conducted using a structured survey sent out via email with the results being analysed quantitatively. The research was limited to engineering graduates working at Sasol. A secondary aim was to explore if there were any differences in motivation between the engineers of various race groups, ages and sexes. Finally the research aimed to rank factors known to affect employee engagement to assist organisations in developing their retention strategies. The most significant finding of the research done, was that the aggressive diversity targeting program within Sasol has not had a significant effect on the employee engagement of white engineers or for that matter on any of the racial groups, ages or sexes investigated. The results from this study supported the findings from various other studies in terms of which factors are perceived as the most important in terms of employee motivation. From the results a two stage employee engagement maturity model was developed which is presented. / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

South African businesses are faced with the immense challenge of transforming themselves so as to reflect post-apartheid South Africa, while at the same time remaining competitive within a globalised market. This research project set out to establish how organisations could effectively channel the potential of an increasingly diverse workforce to derive positive outcomes for the individual and the organisation. To this end, the organisational approach to diversity and its ability to influence the extent of knowledge transfer has been examined.In fully exploring this relationship, four research propositions were developed. A quantitative approach in the form of a survey was utilised to ascertain the perceptions of employees within the banking sector in South Africa. The qualitative phase of the research entailed in-depth interviews with subject matter experts within the industry. This was primarily used to corroborate the survey responses, and to document original thought within the scope of this research. The data obtained through these research instruments was analysed to ascertain the strength of the diversity climate and knowledge transfer as business enablers.The results revealed that a positive diversity climate yields greater levels of knowledge sharing, which consequently results in positive career outcomes for the employee. These factors in aggregate produce both tangible and intangible benefits for the organisation. A conceptual framework has been proposed that depicts the key linkages established through the research findings. / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

Please read the abstract in the section 00front of this document / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

The in-migration of relatively affluent households into disinvested central city neighborhoodsâcommonly referred to as gentrificationâis increasingly common across the United States. There is limited quantitative evidence, however, as to how gentrification relates to the structure and function of neighborhood schools. The purpose of this dissertation is to provide an introductory picture of how a shifting landscape of urban inequality brought about by patterns of gentrification relates to urban schooling in the contemporary U.S. city. In the first section, new statistics are presented on the incidence and distribution of gentrification occurring around public schools in the United States as a whole. Of the roughly 10 percent of urban schools that were located in neighborhoods categorized as disinvested in the year 2000, roughly one in four experienced gentrification in the subsequent decade. However, there exists considerable heterogeneity in the prevalence of gentrification across U.S. metropolitan areas. For example, the share of urban schools located in disinvested neighborhoods in 2000 that subsequently gentrified was over 40 percent in Washington, DC, but effectively zero in Memphis, TN. The second section explores factors correlated with whether gentrification occurs around public schools. Among the population of schools located in gentrifiable neighborhoods at baseline, gentrification was more likely to occur around schools with fewer non-white students, fewer students per teacher, and fewer students overall, controlling for observable differences. School neighborhoods were also more likely to gentrify if the neighborhoods themselves had fewer non-white residents and if schools were located in cities with less racial residential segregation. The third part of this dissertation estimates whether gentrification is associated with changes in disciplinary patterns at neighborhood schools. Evidence is found that gentrification is associated with increased rates of suspension for black students at local high schools, especially in schools wherein black students comprise a minority of the student population.

The recent public availability of large-scale datasets, also known as big data, and digital visualization tools has ushered in new ways of telling stories about the social world. The three papers that comprise this dissertation collectively explore how both youth and young adults learn to engage in the interdisciplinary, representational practices that support becoming modelers, storytellers, and consumers of stories told with big data. The first paper is a literature review that introduces storytelling and modeling with big data as a new cultural activity and a rich design space for learning. The second and third papers draw on a corpus of observational studies and design studies of experimental teaching and dive deeply into interaction in each setting to understand participantsâ comparative, representational practices for assembling models with big data and dynamic visualization tools. The second paper compares three case studies of storytelling and modeling with big data: a professional big data storyteller from the public media and two groups of newcomersâmathematics and social studies preservice teachers in our design-based research studiesâperforming stories about global development trends with an interactive, big data visualization tool. The analysis of video records across cases found that getting personal with big dataâconnecting personal experiences to aggregate trends described in the modelâcan support telling stories about society that counter, challenge, or critique dominant or conventional social narratives. This work motivated the design study iteration reported in the third paper, which examined storytelling and modeling with big data in a personal context: Teenage youth in the public library were invited to create family data storylines about personal family mobility in relation to national census data trends. The third paper found that scaling personal histories to socioeconomic and historical issues represented by big data entails serious data wrangling to align the family story with the data and supports meaningful forms of learning about oneself, oneâs family, and society. Furthermore, locating a population that one identifies with or finding places of meaning in models is an important first step for engagement with big data interfaces.

This study explores the necessity and validity of including cultural competence as a dimension of the construct of quality teaching and classroom community. Through an analysis of existing measures, cultural competence was found to be missing across widely-adopted measures of teacher quality; in contrast, the literature on cultural competence in education, as well studies documenting the importance and validity of including cultural competence in measures of quality medical education, point to the importance of expanding the dominant construct of teacher quality to include aspects of cultural competence. In response to this need, this dissertation analyzes a new observation rubric, the Vision for Student Learning (VfSL). The VfSL is not a traditional, evaluative measure of teacher quality; instead, it is a formative measure of classroom community that scores classrooms based on student actions, rather than teacher actions. The VfSL is grouped into three dimensions: Safe, Brave, and Equitable Classrooms; Rigorous and Culturally Relevant Learning; and Perseverance to Goals. Using exploratory factor analysis and item response theory (IRT) models, this dissertation demonstrates that the VfSL is both reliable and valid as a measure of classroom community, providing initial evidence that inclusion of cultural competence in observation rubrics is both possible and desirable when used strictly to provide formative feedback. Furthermore, the factor structure of the VfSL empirically affirms the theoretically-driven design of the first two dimensions of the measurement instrument and provides evidence that the skills of building classroom culture and enacting rigorous instruction are distinct skill sets that should be targeted to improve classroom community. Revisions to the design of the instrument are suggested based on findings from the factor and IRT analyses. Additionally, while the VfSL shows sensitivity across various demographic groups, researchers and practitioners utilizing the VfSL should be cautious to ensure that any observed differences in classroom community across lines of race and gender are not a function of rater or item bias.

An understanding of the level of both genetic and morphological diversity within a taxon and how that diversity is structured within and across habitats is important when determining the conservation value of that taxon and for successful habitat management programs to be developed. Atlin Lake is a large lake in northern British Columbia and is one of the largest lakes that contain relatively unperturbed populations of lake trout (Salvelinus namaycush). As the top aquatic predator, lake trout in Atlin Lake are a key component of the lake’s fish community and are important for local fisheries. I assayed lake trout from Atlin Lake and other western lake trout populations at eight microsatellite DNA loci and for body morphology to determine: (i) the level of genetic variation present, (ii) the level of substructure that occurs in Atlin Lake, and (iii) whether there was a relationship between the genetic and morphological variation present. STRUCTURE analysis identified five subpopulations within Atlin Lake. Morphological analysis was used to differentiate between the samples collected throughout Atlin Lake. Cluster analysis of size corrected data separated the fish into two groups making Atlin Lake the smallest lake identified to date to possess more than one morphotype. Genetic and morphological groupings were found not to be correlated with each other. Finally, I was interested in whether each of the genetic subpopulations contributed equally to the local fisheries catches. A mixed stock analysis of samples collected from the commercial fishery and recreational anglers indicated that all of the genetic subpopulations contribute to the fishery along with lake trout subpopulations in the interconnecting Tagish Lake; suggesting that no one subpopulation is being depleted by the fisheries. Continued genetic monitoring, however, is necessary to see if the trends in fishery contribution are temporally stable. Future studies should focus on understanding the source of the morphological variation and maintenance of genetic substructure. / Science, Faculty of / Zoology, Department of / Graduate

I investigated the return of plant canopy diversity to degraded spekboom thicket landscapes under restoration treatment. I attempted the reintroduction of five nursery propagated and naturally-occurring plant species in severely degraded Portulacaria afra Jacq. (spekboom) dominated thickets that have been subjected to a restoration method involving the planting of dense rows of P. afra truncheons for various time periods and also in degraded and intact thickets. I also planted nursery propagated P. afra cuttings. An average of 30 propagules of each species, were planted in each of the chosen areas in two distinct seasons that exhibited distinct rainfall peaks. Sixteen propagules of P. afra were also planted in each treatment only once. Propagules of the two thicket woody canopy species (S. longispina and P. capensis) showed a total survival of 1% and 9%, respectively. Survival of L. ferocissimum and R. obovatum was 19% and 70% and all propagules of P. afra survived. Analyses showed that survival is primarily tied to a species effect, with R. obovatum and P. afra showing significantly better survival than the other species. Within the other surviving few species a significant preference for overhanging canopy cover was observed. The results show little significance of restoration treatment for propagule survival, suggesting that a range of conditions is needed for the successful establishment of canopy species that likely involves a microclimate and suitable substrate created by canopy cover and litter fall, combined with an exceptional series of rainfall events. I found that the high costs involved with a biodiversity planting endeavour, and the low survival of propagules of thicket canopy plant species (P. afra excepted), renders the proposed biodiversity planting restoration protocol both ecologically and economically inefficient. Restoration success involves the autogenic regeneration of key species or functional groups within the degraded ecosystem. Heavily degraded spekboom-dominated thicket does not spontaneously regenerate its former canopy species composition and this state of affairs was interpreted in terms of a state-and-transition conceptual model. Floristic analyses of degraded, intact and a range of stands under restoration treatment for varying time periods at two locations in Sundays Spekboomveld revealed that the stands under restoration are progressively regenerating canopy species biodiversity with increasing restoration age, and that intact sites are still the most diverse. The high total carbon content (TCC) measured within the older restored stands Rhinosterhoek (241 t C ha-1 after 50 years at a depth of 50 cm) rivals that recorded for intact spekboom thickets, and the number of recruits found within older restored sites rivals intact sites sampled. 2 The changes recorded in the above- and belowground environments potentially identify P. afra as an ecosystem engineer within spekboom dominated thickets that facillitates the build-up of carbon above- and belowground and the accompanying changes in soil quality and the unique microclimate aboveground, which enables the hypothetical threshold of the degraded state to be transcended. This restoration methodology is accordingly considered efficient and autogenic canopy species return was found to be prominent after a period of 35-50 years of restoration treatment.