List of Titles

An analysis of the academic support policies and strategies for underperforming students at Limpopo universities

Authors: Lavhelani, Nyawasedza Phellecy
Date: 2017
Subjects: Compensatory education--South Africa--Limpopo Universities and colleges--South Africa--Limpopo Support services (Management)--South Africa--Limpopo
Language: English
Type: Thesis , Doctoral , Public Administration
Identifier: http://hdl.handle.net/10353/11784 , vital:39106
Description: The study sought to investigate academic support policies and strategies for underperforming students at Limpopo universities. By focusing on the University of Venda and that of Limpopo (which are located in rural settings), this study will contribute to the body of knowledge addressing the learning needs of underperforming students in resource constrained universities in South Africa. Qualitative research methodology was considered most appropriate in the present study. The researcher used various research instruments as the fact finding strategies. These comprised tools for data collection. The researcher used questionnaires and the survey of secondary sources for data collection. The researcher chose these instruments because this also means discussing the advantages of using questionnaires and reading, for example gaining an in-depth perspective regarding the actual experiences of students who underperform in their studies. The study focused on first year underperforming students, academic support policies and academic support programmes. Permission was sought from the two universities’ Research Departments to conduct this study. Once permission was granted, the questionnaire was sent out to prospective participants. In addition, the researcher involved intra-group despondence analysis. Since the bulk of the data from the questionnaires was qualitative, thematic analysis was utilised. This involved identifying patterns and emerging themes out of the differences and similarities from the despondences’ views. This study was conducted in the Limpopo Province, South Africa, where the two universities are situated.The study population were students, academics, Information Management Officer, CHETL staff and relevant personnel at the Limpopo. Universities. As envisaged, a total of 136 participants were chosen to participate in the study.
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Date Issued: 2017

The growth and reproduction of the freshwater limpet Burnupia stenochorias (Pulmonata, Ancylidae), and an evaluation of its use as an ecotoxicology indicator in whole effluent testing

- Davies-Coleman, H D (Heather D)

Authors: Davies-Coleman, H D (Heather D)
Date: 2002
Subjects: Ancylidae Effluent quality Toxicity testing
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:5703 , http://hdl.handle.net/10962/d1005389
Description: For the protection of the ecological Reserve in South Africa, the proposed introduction of compulsory toxicity testing in the licensing of effluent discharges necessitates the development of whole effluent toxicity testing. The elucidation of the effects of effluent on the local indigenous populations of organisms is essential before hazard and risk assessment can be undertaken. The limpet Burnupia stenochorias, prevalent in the Eastern Cape of South Africa, was chosen to represent the freshwater molluscs as a potential toxicity indicator. Using potassium dichromate (as a reference toxicant) and a textile whole effluent, the suitability of B. stenochorias was assessed under both acute and chronic toxicity conditions in the laboratory. In support of the toxicity studies, aspects of the biology of B. stenochorias were investigated under both natural and laboratory conditions. Using Principal Component and Discriminant Function Analyses, the relative shell morphometrics of three feral populations of B. stenochorias were found to vary. Length was shown to adequately represent growth of the shell, although the inclusion of width measurements is more statistically preferable. Two of the feral populations, one in impacted water, were studied weekly for 52 weeks to assess natural population dynamics. Based on the Von Bertalanffy Growth Equation, estimates of growth and longevity were made for this species, with growth highly seasonal. Age is not easily discerned from shell size. Egg laying occurred all year round, with early summer (peak egg lay), mid summer (a second, smaller peak in egg lay), and winter (limited presence of eggs) phases. In toxicity testing, consideration is given to the choice of the test organism based on age and sexual development. Consequently, the sexual development of B. stenochorias relative to shell length was determined with the aid of histological examinations of transverse sections of limpets, of all sizes, collected over one year. Limpets less than 3mm shell length were found to be immature in the development of the oocytes and spermatozoa, and were later chosen for acute toxicity tests. A laboratory diet was developed, for both culturing and maintaining of the limpets during toxicity tests; however, the diet requires optimisation. Under laboratory conditions, growth was linear, and individual fecundity highly variable. Successful methods for the collection of limpets from naturally occurring populations, and their acclimation to the laboratory were developed. Three B. stenochorias populations, representing different hydrological and water quality conditions, were compared to a laboratory population (maintained for three years) in their responses to the textile whole effluent and potassium dichromate. Under acute conditions, variability of mortality between limpet populations and between seasons was consistent with acceptable international standards. However, seasonal differences between feral limpets were apparent, with early summer limpets significantly more susceptible to both potassium dichromate and textile effluent than winter limpets. Although mortality occurred within the effluent at all concentrations, no 96 hour LC₅₀ values were obtained. The chronic toxicity effects of the textile whole effluent were assessed over the entire life cycle of B. stenochorias, based on survival, growth and reproductive effects. Lower concentrations of effluent (# 10%) gave greater variability of responses and toxicity than higher concentrations, with a 43 day LC₅₀ of 3.9% effluent. The No Observed Effect Concentrations for survival (over 43 days) were calculated in consecutive years as 0.1% and 1% effluent. Survival is considered a useful tool for determining toxicity endpoints using B. stenochorias. Limpet growth remained linear in effluent, with an apparent stimulation of growth at the 3-10% effluent concentration, confusing the toxicity and variability assessments. The possible addition of nutrients from the effluent points to either a potential inadequacy of the food quality provided in the chronic assessment, or the presence in the effluent of growth stimulants. Growth was also found to be too variable to allow adequate statistical conclusions about the toxicity of the effluent, although it is suggested that growth may be useful in the assessment of single compounds. Despite large individual variability in fecundity, statistical differences were discernible between effluent concentrations. The application of fecundity of B. stenochorias in hazard assessment therefore warrants further investigation. It was concluded that an assessment of textile whole effluent toxicity to B. stenochorias over an entire life cycle, and an F1 generation, is unnecessary. The development of the bucket/plastic bag method for both acute and chronic toxicity assessment of B. stenochorias was useful. In the final assessment of the usefulness of B. stenochorias as a toxicity indicator, toxicity endpoints were compared with those of the standard laboratory organism Daphnia pulex. Both in acute and chronic toxicity, B. stenochorias was found to be more sensitive. B. stenochorias is therefore considered valuable as a South African freshwater molluscan ecotoxicological indicator, with a place in hazard assessment, although further development and research is necessary before the limpet can be effectively used.
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Date Issued: 2002

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