Khoekhoe lexical borrowing in Namaqualand Afrikaans
- Authors: Christie, Camilla Rose
- Date: 2020
- Subjects: Code switching (Linguistics) , Afrikaans language -- Foreign elements -- Nama , Nama language -- Foreign elements -- Afrikaans , Afrikaans language -- Phonology , Nama language -- Phonology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/168385 , vital:41576
- Description: Although several languages in the Khoekhoe branch were historically spoken alongside Afrikaans in bilingual speech communities throughout the Western and Northern Cape, the last century has seen abrupt and catastrophic language loss, resulting in a shift from a bilingual to a monolingual paradigm. However, a number of ethnobotanical surveys conducted in the Namaqualand region of the Northern Cape over the last forty years have recorded the retention of Khoekhoe-branch plant names by monolingual Afrikaans speakers. Such surveys make no attempt to source these loanwords to their Khoekhoe-branch targets, do not make use of the standardised Namibian Khoekhoe orthography, and often resort to transcribing loaned click consonants using only ‘t’. This study undertakes a sociohistorical linguistic investigation into the etymological origins and contemporary usage of these loaned plant names in order to develop a clearer understanding of language contact and lexical borrowing in the Namaqualand region. Following the lexicographical compilation of a representative corpus of loanwords, this study conducts a series of semi-structured interviews with monolingual speakers of Namaqualand Afrikaans. Qualitative sociolinguistic analysis of these interviews reveals that, although loanwords are perceived to be of Nama origin, they are semantically opaque beyond pragmatic reference. Preliminary phonological observations identify a loss of phonemic contrastivity in loaned clicks coupled with a high incidence of variability, and suggest epenthetic stop insertion and epenthetic nasalisation as two possible strategies facilitating click loan. Synthesising these ob servations, this study speculates that the use of loanwords hosting clicks may enjoy a degree of covert prestige in Namaqualand Afrikaans, which may in turn shed light on historical sociolinguistic processes of click diffusion. It recommends that urgent and immediate attention be focused on the usage, sociolinguistic status, and regional variation of Nama within the Northern Cape, and advocates strongly for cooperation and improved communication between linguists and ethnobotanists.
- Full Text:
- Authors: Christie, Camilla Rose
- Date: 2020
- Subjects: Code switching (Linguistics) , Afrikaans language -- Foreign elements -- Nama , Nama language -- Foreign elements -- Afrikaans , Afrikaans language -- Phonology , Nama language -- Phonology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/168385 , vital:41576
- Description: Although several languages in the Khoekhoe branch were historically spoken alongside Afrikaans in bilingual speech communities throughout the Western and Northern Cape, the last century has seen abrupt and catastrophic language loss, resulting in a shift from a bilingual to a monolingual paradigm. However, a number of ethnobotanical surveys conducted in the Namaqualand region of the Northern Cape over the last forty years have recorded the retention of Khoekhoe-branch plant names by monolingual Afrikaans speakers. Such surveys make no attempt to source these loanwords to their Khoekhoe-branch targets, do not make use of the standardised Namibian Khoekhoe orthography, and often resort to transcribing loaned click consonants using only ‘t’. This study undertakes a sociohistorical linguistic investigation into the etymological origins and contemporary usage of these loaned plant names in order to develop a clearer understanding of language contact and lexical borrowing in the Namaqualand region. Following the lexicographical compilation of a representative corpus of loanwords, this study conducts a series of semi-structured interviews with monolingual speakers of Namaqualand Afrikaans. Qualitative sociolinguistic analysis of these interviews reveals that, although loanwords are perceived to be of Nama origin, they are semantically opaque beyond pragmatic reference. Preliminary phonological observations identify a loss of phonemic contrastivity in loaned clicks coupled with a high incidence of variability, and suggest epenthetic stop insertion and epenthetic nasalisation as two possible strategies facilitating click loan. Synthesising these ob servations, this study speculates that the use of loanwords hosting clicks may enjoy a degree of covert prestige in Namaqualand Afrikaans, which may in turn shed light on historical sociolinguistic processes of click diffusion. It recommends that urgent and immediate attention be focused on the usage, sociolinguistic status, and regional variation of Nama within the Northern Cape, and advocates strongly for cooperation and improved communication between linguists and ethnobotanists.
- Full Text:
Kwakhe kwanje phi na?
- Authors: Qwesha, Mziwonke
- Date: 2020
- Subjects: South African drama (Xhosa) -- 21st century , Xhosa drama -- 21st century
- Language: Xhosa
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/144476 , vital:38349
- Description: Creative work portfolio - drama in isiXhosa.
- Full Text:
- Authors: Qwesha, Mziwonke
- Date: 2020
- Subjects: South African drama (Xhosa) -- 21st century , Xhosa drama -- 21st century
- Language: Xhosa
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/144476 , vital:38349
- Description: Creative work portfolio - drama in isiXhosa.
- Full Text:
Learning about volunteering: an exploration of literacy volunteers' experiences
- Authors: Yendall, Kaitlin Amy
- Date: 2020
- Subjects: Literacy -- Study and teaching -- South Africa , Literacy programs -- South Africa , Voluntarism -- South Africa , Volunteer workers in community development -- Training of , Service learning , Language and education -- South Africa , Language arts (Primary) , English language -- Study and teaching (Elementary) , Volunteer workers in Education -- Training of
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/138336 , vital:37623
- Description: After almost 25 years of democracy in South Africa, not everyone has access to the same quality education. The responsibility of creating a literate society however cannot rely on the national government and schools alone, but instead needs to fall on the shoulders of various stakeholders. Volunteers in particular have an important role to play in remedying the current literacy crisis experienced in South Africa. This study takes the form of a case study approach and examines the experiences of Project Read literacy volunteers. A telephonic survey and two focus group discussions were conducted in order to determine who it is that volunteers for the programme; what prompts these particular individuals to volunteer; the perceived benefits of volunteering; and how volunteers report on their volunteering experiences. Although the Project Read programme is focused on the early literacy development of learners, volunteers seemed to undergo a developmental process themselves – something they had not anticipated at the start of their volunteering journey. This study illustrates the power of meaningful relationships in breaking down artificial categories and in bringing about important change with regards to the perceptions and attitudes of individuals towards community engagement. It is hoped that the data generated through this study will assist in recruiting and retaining more literacy volunteers through feedback to the NGO. In this way more children will be assisted to enhance their literacy competencies, from which they can build and achieve.
- Full Text:
- Authors: Yendall, Kaitlin Amy
- Date: 2020
- Subjects: Literacy -- Study and teaching -- South Africa , Literacy programs -- South Africa , Voluntarism -- South Africa , Volunteer workers in community development -- Training of , Service learning , Language and education -- South Africa , Language arts (Primary) , English language -- Study and teaching (Elementary) , Volunteer workers in Education -- Training of
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/138336 , vital:37623
- Description: After almost 25 years of democracy in South Africa, not everyone has access to the same quality education. The responsibility of creating a literate society however cannot rely on the national government and schools alone, but instead needs to fall on the shoulders of various stakeholders. Volunteers in particular have an important role to play in remedying the current literacy crisis experienced in South Africa. This study takes the form of a case study approach and examines the experiences of Project Read literacy volunteers. A telephonic survey and two focus group discussions were conducted in order to determine who it is that volunteers for the programme; what prompts these particular individuals to volunteer; the perceived benefits of volunteering; and how volunteers report on their volunteering experiences. Although the Project Read programme is focused on the early literacy development of learners, volunteers seemed to undergo a developmental process themselves – something they had not anticipated at the start of their volunteering journey. This study illustrates the power of meaningful relationships in breaking down artificial categories and in bringing about important change with regards to the perceptions and attitudes of individuals towards community engagement. It is hoped that the data generated through this study will assist in recruiting and retaining more literacy volunteers through feedback to the NGO. In this way more children will be assisted to enhance their literacy competencies, from which they can build and achieve.
- Full Text:
Life after training: professional experiences of recently qualified clinical and counselling psychologists in South Africa
- Authors: Haine, Phillipa
- Date: 2020
- Subjects: Clinical psychologists – South Africa , Counseling psychologists – South Africa , Psychologists -- Job stress -- South Africa , Psychologists -- Employment -- South Africa , Career development -- South Africa , Psychologists -- Training of -- South Africa , Life change events , Qualitative research
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/142421 , vital:38078
- Description: Professional psychology in South Africa has experienced numerous transformations since its tainted historical affiliation with the apartheid regime. However, despite the profession’s attempts to respond to the burgeoning mental health needs of the country, psychologists in South Africa continue to be confronted by a number of challenges within the professional field. International research suggests that early career psychologists, in particular, experience further challenges in adjusting to new professional careers. Considering the dearth of research on this topic within local literature, the aim of this study was to gain an in-depth understanding of the lived professional experiences of recently qualified clinical and counselling psychologists in South Africa, following training. An interpretive phenomenological method was employed to investigate the fundamental early career professional experiences of participants, as well as the meanings participants attributed to these experiences. Four participants were recruited using purposive sampling. Data was collected through the use of semi-structured, one-on-one, Skype interviews, and the interview data were analysed using interpretative phenomenological analysis. The study revealed four super-ordinate themes, including: (i) Training as a ‘rite of passage’; (ii) Expectations for a professional future; (iii) Professional psychology: Entering the work space; and (iv) Future directions. The findings suggest that clinical and counselling psychologists’ experiences as recently qualified professionals in South Africa are both positive and negative, with the overall experience being positive. Emerging themes suggest that early career psychologists are faced by a number of personal and professional challenges on entering the work place. Furthermore, findings suggest that the early career experiences of recently qualified clinical and counselling psychologists in South Africa might not necessarily be due to personal choice, but rather due to greater systemic factors, such as limited available posts, maladministration, the devalued status of mental healthcare in comparison to other healthcare concerns in the country, an unresponsive marketplace and limited efforts by government to accommodate psychologists in different contexts
- Full Text:
- Authors: Haine, Phillipa
- Date: 2020
- Subjects: Clinical psychologists – South Africa , Counseling psychologists – South Africa , Psychologists -- Job stress -- South Africa , Psychologists -- Employment -- South Africa , Career development -- South Africa , Psychologists -- Training of -- South Africa , Life change events , Qualitative research
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/142421 , vital:38078
- Description: Professional psychology in South Africa has experienced numerous transformations since its tainted historical affiliation with the apartheid regime. However, despite the profession’s attempts to respond to the burgeoning mental health needs of the country, psychologists in South Africa continue to be confronted by a number of challenges within the professional field. International research suggests that early career psychologists, in particular, experience further challenges in adjusting to new professional careers. Considering the dearth of research on this topic within local literature, the aim of this study was to gain an in-depth understanding of the lived professional experiences of recently qualified clinical and counselling psychologists in South Africa, following training. An interpretive phenomenological method was employed to investigate the fundamental early career professional experiences of participants, as well as the meanings participants attributed to these experiences. Four participants were recruited using purposive sampling. Data was collected through the use of semi-structured, one-on-one, Skype interviews, and the interview data were analysed using interpretative phenomenological analysis. The study revealed four super-ordinate themes, including: (i) Training as a ‘rite of passage’; (ii) Expectations for a professional future; (iii) Professional psychology: Entering the work space; and (iv) Future directions. The findings suggest that clinical and counselling psychologists’ experiences as recently qualified professionals in South Africa are both positive and negative, with the overall experience being positive. Emerging themes suggest that early career psychologists are faced by a number of personal and professional challenges on entering the work place. Furthermore, findings suggest that the early career experiences of recently qualified clinical and counselling psychologists in South Africa might not necessarily be due to personal choice, but rather due to greater systemic factors, such as limited available posts, maladministration, the devalued status of mental healthcare in comparison to other healthcare concerns in the country, an unresponsive marketplace and limited efforts by government to accommodate psychologists in different contexts
- Full Text:
Macro-locational determinants and motive of Chinese foreign direct investment in Cameroon
- Authors: Andangnui, Quintabella
- Date: 2020
- Subjects: Investments, Foreign -- Cameroon , Investments, Chinese -- Cameroon , Corporations, Foreign -- Cameroon , Industrial location -- Cameroon
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/163157 , vital:41014
- Description: This research falls under the general themes of macro-locational determinants and motives of Foreign Direct Investment (FDI) and the challenges faced by FDIs. Specifically, the research focuses on macro-locational determinants of FDI and the motives of Chinese FDI in Cameroon, and the challenges faced by Chinese FDI in Cameroon. This research is motivated by China’s interest in African countries as well as the reciprocal interest in Chinese FDI by African countries, especially Cameroon. While various FDI theories and previous empirical studies indicate that macro-locational determinants of FDI constitute a country’s principal comparative advantage to attract FDI, there is still no universally acceptable set of macro-locational determinants of FDI. Furthermore, some empirical studies assert that Chinese FDI does not follow conventional FDI theories or western approaches to FDI, especially when investing in African countries. It is suggested that some widely accepted macro-locational determinants of FDI are frequently ignored by Chinese FDI. While FDI theories identify four motives for FDI (resource-, market-, efficiency-, and strategic asset-seeking) as the main motives for investing in a foreign country, the motives for Chinese FDI, especially in Africa, have been questioned by some scholars, the media and politicians, due to the significant but seemingly counterintuitive investments made by Chinese state-owned FDI in politically unstable resource-rich African countries. Furthermore, differences in the motives of Chinese privately owned and state-owned firms identified in previous empirical studies have raised concerns, particularly regarding the motives of state-owned Chinese firms in Africa which suggest a stance of neo-colonialism by Chinese state-owned FDI. The research aims to identify the significant macro-locational determinants of Chinese FDI in Cameroon, to provide clarity on the motives of Chinese FDI and to identify the challenges faced by Chinese FDI in Cameroon. To achieve the aim of this research, hypothetical relationships based on FDI theory and previous empirical research were formulated between Chinese FDI and the proposed macro-locational determinants of FDI and the four identified motives of FDI. In this research, a positivist research paradigm using quantitative methods was followed. Accordingly, the research design and methodology was underpinned by the positivist paradigm. A descriptive and analytical survey methodology was utilised, using both primary and secondary data sources. Secondary data was collected from reliable and credible databases for the period 2004 to 2018 to generate a time series to test the hypothetical relationships pertaining to the macro-locational determinants of Chinese FDI in Cameroon. To test the hypothetical relationships pertaining to the motives of Chinese FDI and to identify the challenges of Chinese FDI in Cameroon, primary data was collected by means of a questionnaire using convenience and snowball sampling techniques. The validity of the findings on the macro-locational determinants of FDI was confirmed through unit root and cointegration tests. Confirmatory Factor Analysis (CFA) and Cronbach’s alpha coefficients were used to ensure the validity and reliability of the findings on the motives of FDI. To assess the hypothetical relationships on the motives for Chinese FDI, the hypothetical relationship on the macro-locational determinants of FDI was determined using Ordinary Least Square (OLS) regression, t-tests, one-way ANOVA, descriptive statistics and logistic regression. In addition, descriptive statistics were used to analyse the data on the challenges of Chinese FDI. The findings indicated that the main macro-locational determinants of Chinese FDI in Cameroon included market size, political risk, limited trade openness, real effective exchange rate, interest rate and human capital. The findings also indicated that market-seeking constitutes the main motive of privately owned Chinese FDI in Cameroon. The findings also indicated that the top four challenges faced by Chinese FDI in Cameroon include corruption, the ambiguity of the legal system of Cameroon, the difficulty to negotiate with government and privatisation officials and high levels of taxes. The findings of this research serve as a test of theory, given that they determine whether the macro-locational determinants identified from FDI theories are also significant macro-locational determinants of Chinese FDI. Furthermore, the findings have the potential to assist in policy formulation aimed at encouraging Chinese FDI into Cameroon. The findings could also assist the Cameroonian government to allocate national resources efficiently by prioritising identified macro-locational determinants. The findings provide clarity on the motives of Chinese FDI in Cameroon and could assist the government to negotiate better deals that may enable Cameroon to benefit optimally from Chinese FDI.
- Full Text:
- Authors: Andangnui, Quintabella
- Date: 2020
- Subjects: Investments, Foreign -- Cameroon , Investments, Chinese -- Cameroon , Corporations, Foreign -- Cameroon , Industrial location -- Cameroon
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/163157 , vital:41014
- Description: This research falls under the general themes of macro-locational determinants and motives of Foreign Direct Investment (FDI) and the challenges faced by FDIs. Specifically, the research focuses on macro-locational determinants of FDI and the motives of Chinese FDI in Cameroon, and the challenges faced by Chinese FDI in Cameroon. This research is motivated by China’s interest in African countries as well as the reciprocal interest in Chinese FDI by African countries, especially Cameroon. While various FDI theories and previous empirical studies indicate that macro-locational determinants of FDI constitute a country’s principal comparative advantage to attract FDI, there is still no universally acceptable set of macro-locational determinants of FDI. Furthermore, some empirical studies assert that Chinese FDI does not follow conventional FDI theories or western approaches to FDI, especially when investing in African countries. It is suggested that some widely accepted macro-locational determinants of FDI are frequently ignored by Chinese FDI. While FDI theories identify four motives for FDI (resource-, market-, efficiency-, and strategic asset-seeking) as the main motives for investing in a foreign country, the motives for Chinese FDI, especially in Africa, have been questioned by some scholars, the media and politicians, due to the significant but seemingly counterintuitive investments made by Chinese state-owned FDI in politically unstable resource-rich African countries. Furthermore, differences in the motives of Chinese privately owned and state-owned firms identified in previous empirical studies have raised concerns, particularly regarding the motives of state-owned Chinese firms in Africa which suggest a stance of neo-colonialism by Chinese state-owned FDI. The research aims to identify the significant macro-locational determinants of Chinese FDI in Cameroon, to provide clarity on the motives of Chinese FDI and to identify the challenges faced by Chinese FDI in Cameroon. To achieve the aim of this research, hypothetical relationships based on FDI theory and previous empirical research were formulated between Chinese FDI and the proposed macro-locational determinants of FDI and the four identified motives of FDI. In this research, a positivist research paradigm using quantitative methods was followed. Accordingly, the research design and methodology was underpinned by the positivist paradigm. A descriptive and analytical survey methodology was utilised, using both primary and secondary data sources. Secondary data was collected from reliable and credible databases for the period 2004 to 2018 to generate a time series to test the hypothetical relationships pertaining to the macro-locational determinants of Chinese FDI in Cameroon. To test the hypothetical relationships pertaining to the motives of Chinese FDI and to identify the challenges of Chinese FDI in Cameroon, primary data was collected by means of a questionnaire using convenience and snowball sampling techniques. The validity of the findings on the macro-locational determinants of FDI was confirmed through unit root and cointegration tests. Confirmatory Factor Analysis (CFA) and Cronbach’s alpha coefficients were used to ensure the validity and reliability of the findings on the motives of FDI. To assess the hypothetical relationships on the motives for Chinese FDI, the hypothetical relationship on the macro-locational determinants of FDI was determined using Ordinary Least Square (OLS) regression, t-tests, one-way ANOVA, descriptive statistics and logistic regression. In addition, descriptive statistics were used to analyse the data on the challenges of Chinese FDI. The findings indicated that the main macro-locational determinants of Chinese FDI in Cameroon included market size, political risk, limited trade openness, real effective exchange rate, interest rate and human capital. The findings also indicated that market-seeking constitutes the main motive of privately owned Chinese FDI in Cameroon. The findings also indicated that the top four challenges faced by Chinese FDI in Cameroon include corruption, the ambiguity of the legal system of Cameroon, the difficulty to negotiate with government and privatisation officials and high levels of taxes. The findings of this research serve as a test of theory, given that they determine whether the macro-locational determinants identified from FDI theories are also significant macro-locational determinants of Chinese FDI. Furthermore, the findings have the potential to assist in policy formulation aimed at encouraging Chinese FDI into Cameroon. The findings could also assist the Cameroonian government to allocate national resources efficiently by prioritising identified macro-locational determinants. The findings provide clarity on the motives of Chinese FDI in Cameroon and could assist the government to negotiate better deals that may enable Cameroon to benefit optimally from Chinese FDI.
- Full Text:
Making sense of a scam: MMM Mutual Fund participants in Kagiso negotiate dissenting mainstream new coverage on social media
- Authors: Boqo, Bella Makhulu
- Date: 2020
- Subjects: Ponzi schemes -- South Africa , Fraud -- South Africa , Social media -- Influence -- South Africa , Mavrodi Mondial Moneybox -- In mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145771 , vital:38465
- Description: Pyramid, Ponzi and various fraudulent investment schemes are common feature in post-apartheid South Africa. The record levels of participation have generated much discussion in public discourse. Newspapers often abound with reports of participants who’ve lost large sums of money – in many instances their life savings. While on social media, thousands debate the merits and threats of new ventures as they emerge, in some instances using these platforms as the newest recruitment platforms. The sheer size and frequency of their appearance especially in post-revolutionary societies – those which experienced dramatic structural transformation following the end of the Cold War and growth of a neoliberal market economy – has drawn substantive scholarly attention. Much like media reports, however, this research often points to the morality of such practices, asking questions like what factors lead people to make the apparently irrational decision to participate in a scam? This study, however, contributes to a different body of emerging literature concerned with the larger structural contexts in which such forms of economic practice and organisation exist, and the meanings participants make of their involvement. Looking at the recently high profile of case of Mavrodi Mondial Moneybox (MMM), it employs a qualitative research methodology rooted in cultural studies to examine how participants based in the Johannesburg township of Kagiso used social media, specifically WhatsApp, to make sense of and contest the dissenting mainstream news coverage about MMM. Ultimately, it is a question of how their participation in particularly illegal pyramid or Ponzi type schemes and opposition to traditional news reports are rooted in their lived experiences, and what opportunities social media offer as alternate platforms for meaning-making, deliberation and public contestation.
- Full Text:
- Authors: Boqo, Bella Makhulu
- Date: 2020
- Subjects: Ponzi schemes -- South Africa , Fraud -- South Africa , Social media -- Influence -- South Africa , Mavrodi Mondial Moneybox -- In mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145771 , vital:38465
- Description: Pyramid, Ponzi and various fraudulent investment schemes are common feature in post-apartheid South Africa. The record levels of participation have generated much discussion in public discourse. Newspapers often abound with reports of participants who’ve lost large sums of money – in many instances their life savings. While on social media, thousands debate the merits and threats of new ventures as they emerge, in some instances using these platforms as the newest recruitment platforms. The sheer size and frequency of their appearance especially in post-revolutionary societies – those which experienced dramatic structural transformation following the end of the Cold War and growth of a neoliberal market economy – has drawn substantive scholarly attention. Much like media reports, however, this research often points to the morality of such practices, asking questions like what factors lead people to make the apparently irrational decision to participate in a scam? This study, however, contributes to a different body of emerging literature concerned with the larger structural contexts in which such forms of economic practice and organisation exist, and the meanings participants make of their involvement. Looking at the recently high profile of case of Mavrodi Mondial Moneybox (MMM), it employs a qualitative research methodology rooted in cultural studies to examine how participants based in the Johannesburg township of Kagiso used social media, specifically WhatsApp, to make sense of and contest the dissenting mainstream news coverage about MMM. Ultimately, it is a question of how their participation in particularly illegal pyramid or Ponzi type schemes and opposition to traditional news reports are rooted in their lived experiences, and what opportunities social media offer as alternate platforms for meaning-making, deliberation and public contestation.
- Full Text:
Managing the invasive aquatic plant Sagittaria platyphylla (Engelm.) J.G. Sm(Alismataceae): problems and prospects
- Ndlovu, Mpilonhle Sinothando
- Authors: Ndlovu, Mpilonhle Sinothando
- Date: 2020
- Subjects: Aquatic weeds -- Biological control -- South Africa , Sagittaria latifolia -- Biological control -- South Africa , Noxious weeds -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa , Listronotus , Insects as biological pest control agents
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167121 , vital:41439
- Description: Sagittaria platyphylla (Engelm.) J.G.Sm. (Alismataceae), commonly known as Delta arrowhead, is an invasive aquatic macrophyte native to southern United States of America (USA) that has become a serious weed in freshwater systems in South Africa, New Zealand, Australia, and recently China. In South Africa, the plant was first detected in Krantzkloof Nature Reserve, KwaZulu-Natal Province in 2008, and due to its known impact in other countries, it was listed as a Category 1a invader species under the National Environmental Management: Biodiversity Act 2004 (NEM: BA). This listing required mechanical and chemical control methods to be implemented by the South African National Biodiversity Institute’s (SANBI), Invasive Species Programme (ISP), with the aim of eradicating the weed. Despite the eradication efforts, by 2016, the weed was recognized as one of the country’s top 10 worst and fastest spreading invasive alien plants. Since its introduction in 2008, the plant has spread both within and between sites in South Africa, increasing from one site in 2008 to 72 sites by 2019. Once introduced into lotic systems, the plant spread rapidly downstream, in some cases up to 120km within six years, with an average of 10 km per year. Extirpation over the last ten years was only possible at a limited number of sites. Under the current management approach, the invasion is foreseen to spread to new sites within a 5 km radius of the current populations. Due to the failure of conventional control mechanisms, biological control is currently being considered as a potential control option. Four potential biological control agents are under investigation, but none have been released. Amongst them is the fruit and flower feeding weevil Listronotus appendiculatus Bohm. (Coleoptera: Curculionidae) which showed most potential as a suitable biological control agent. This study demonstrated that L. appendiculatus herbivory negatively influenced the overall fitness of S. platyphylla by reducing the plant’s growth rate and above ground biomass. Listronotus appendiculatus herbivory also reduced the plant’s size and the potential to kill adult plants. Most importantly, L. appendiculatus larval feeding damage significantly reduce viable-germinating seeds, the weed’s primary dispersal mechanism. Therefore, a biological control programme is advised to be integrated within the current management plan.
- Full Text:
- Authors: Ndlovu, Mpilonhle Sinothando
- Date: 2020
- Subjects: Aquatic weeds -- Biological control -- South Africa , Sagittaria latifolia -- Biological control -- South Africa , Noxious weeds -- Biological control -- South Africa , Invasive plants -- Biological control -- South Africa , Listronotus , Insects as biological pest control agents
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167121 , vital:41439
- Description: Sagittaria platyphylla (Engelm.) J.G.Sm. (Alismataceae), commonly known as Delta arrowhead, is an invasive aquatic macrophyte native to southern United States of America (USA) that has become a serious weed in freshwater systems in South Africa, New Zealand, Australia, and recently China. In South Africa, the plant was first detected in Krantzkloof Nature Reserve, KwaZulu-Natal Province in 2008, and due to its known impact in other countries, it was listed as a Category 1a invader species under the National Environmental Management: Biodiversity Act 2004 (NEM: BA). This listing required mechanical and chemical control methods to be implemented by the South African National Biodiversity Institute’s (SANBI), Invasive Species Programme (ISP), with the aim of eradicating the weed. Despite the eradication efforts, by 2016, the weed was recognized as one of the country’s top 10 worst and fastest spreading invasive alien plants. Since its introduction in 2008, the plant has spread both within and between sites in South Africa, increasing from one site in 2008 to 72 sites by 2019. Once introduced into lotic systems, the plant spread rapidly downstream, in some cases up to 120km within six years, with an average of 10 km per year. Extirpation over the last ten years was only possible at a limited number of sites. Under the current management approach, the invasion is foreseen to spread to new sites within a 5 km radius of the current populations. Due to the failure of conventional control mechanisms, biological control is currently being considered as a potential control option. Four potential biological control agents are under investigation, but none have been released. Amongst them is the fruit and flower feeding weevil Listronotus appendiculatus Bohm. (Coleoptera: Curculionidae) which showed most potential as a suitable biological control agent. This study demonstrated that L. appendiculatus herbivory negatively influenced the overall fitness of S. platyphylla by reducing the plant’s growth rate and above ground biomass. Listronotus appendiculatus herbivory also reduced the plant’s size and the potential to kill adult plants. Most importantly, L. appendiculatus larval feeding damage significantly reduce viable-germinating seeds, the weed’s primary dispersal mechanism. Therefore, a biological control programme is advised to be integrated within the current management plan.
- Full Text:
Market timing and portfolio returns: an empirical analysis of the potential profitability of buy-sell strategies, based on South African equities 2009-2018
- Authors: Mulweli, Ramulongo
- Date: 2020
- Subjects: Johannesburg Stock Exchange , Stocks -- Charts, diagrams, etc. , Investment analysis -- South Africa , Stocks -- South Africa , Stocks -- South Africa -- Cast studies
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/144487 , vital:38350
- Description: South Africa’s financial markets have become larger and more complex over recent decades. The number of market participants who are using technical analysis techniques to predict the market’s movement has been growing rapidly. This research aims to investigate if historical share prices can be used when forecasting the market’s direction and to examine the profitability of the Japanese candlestick patterns. The study is based on ten companies selected from the JSE top 40 2019 composition. These are Aspen Pharmacy Holding, Capitec Bank Holding LTD, Discovery LTD, Kumba Iron Ore LTD, Mondi PLC, Mr. Price Group LTD, MTN Group LTD, Naspers LTD, SASOL LTD, and Shoprite Holdings LTD. These were selected from the JSE top 40 based on market capitalization and sector. This research analyzes eight candlestick reversal patterns; four are bullish patterns namely: doji star, hammer, bullish engulfing and the piercing lines and the other four are bearish patterns namely: shooting star, hanging man, bearish engulfing and the dark cloud cover. The ARCH and GARCH models are used to test for correlation between past share prices and future share prices and the binomial test and the mean return calculations were used to test the profitability of candlestick patterns. The sample is from Thomson DataStream 2019 and IRESS SA 2019 and covers ten years with 2496 observations starting from 02 January 2009 to 31 December 2018. The findings from the ARCH and GARCH tests revealed that there is a serial correlation between the returns from the previous day and the returns for the current day. The results from the mean returns and the binomial tests show strong evidence that the shooting star, hanging man, bearish engulfing and the bulling engulfing are statistically significant in predicting the share price movements. On the other hand, there was no evidence that the dark cloud cover, piercing lines, and the bullish doji can predict share price movements. Additionally, further studies on this topic could be improved by adding different candlestick patterns and the total number of companies analyzed. The results could also be improved by analyzing the candlestick reversal patterns when they are used with other trading rules such as support resistance levels and oscillators.
- Full Text:
- Authors: Mulweli, Ramulongo
- Date: 2020
- Subjects: Johannesburg Stock Exchange , Stocks -- Charts, diagrams, etc. , Investment analysis -- South Africa , Stocks -- South Africa , Stocks -- South Africa -- Cast studies
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/144487 , vital:38350
- Description: South Africa’s financial markets have become larger and more complex over recent decades. The number of market participants who are using technical analysis techniques to predict the market’s movement has been growing rapidly. This research aims to investigate if historical share prices can be used when forecasting the market’s direction and to examine the profitability of the Japanese candlestick patterns. The study is based on ten companies selected from the JSE top 40 2019 composition. These are Aspen Pharmacy Holding, Capitec Bank Holding LTD, Discovery LTD, Kumba Iron Ore LTD, Mondi PLC, Mr. Price Group LTD, MTN Group LTD, Naspers LTD, SASOL LTD, and Shoprite Holdings LTD. These were selected from the JSE top 40 based on market capitalization and sector. This research analyzes eight candlestick reversal patterns; four are bullish patterns namely: doji star, hammer, bullish engulfing and the piercing lines and the other four are bearish patterns namely: shooting star, hanging man, bearish engulfing and the dark cloud cover. The ARCH and GARCH models are used to test for correlation between past share prices and future share prices and the binomial test and the mean return calculations were used to test the profitability of candlestick patterns. The sample is from Thomson DataStream 2019 and IRESS SA 2019 and covers ten years with 2496 observations starting from 02 January 2009 to 31 December 2018. The findings from the ARCH and GARCH tests revealed that there is a serial correlation between the returns from the previous day and the returns for the current day. The results from the mean returns and the binomial tests show strong evidence that the shooting star, hanging man, bearish engulfing and the bulling engulfing are statistically significant in predicting the share price movements. On the other hand, there was no evidence that the dark cloud cover, piercing lines, and the bullish doji can predict share price movements. Additionally, further studies on this topic could be improved by adding different candlestick patterns and the total number of companies analyzed. The results could also be improved by analyzing the candlestick reversal patterns when they are used with other trading rules such as support resistance levels and oscillators.
- Full Text:
Metallophthalocyanines linked to metal nanoparticles and folic acid for use in photodynamic therapy of cancer and photoinactivation of bacterial microorganisms.
- Authors: Matlou, Gauta Gold
- Date: 2020
- Subjects: Cancer -- Photochemotherapy , Nanoparticles , Phthalocyanines , Anti-infective agents -- Therapeutic use , Photochemotherapy , Photochemistry
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166540 , vital:41377
- Description: This thesis presents on the synthesis and characterization of novel asymmetric and symmetrical metallophthalocyanines (MPcs) substituted with carboxylic acid functional groups and centrally metallated with zinc and indium. The MPcs are further covalently linked to cysteine capped silver nanoparticles (cys-AgNPs), amino functionalized magnetic nanoparticles (AMNPs) and folic acid (FA) through an amide bond between the carboxylic group of MPcs and the amino group of FA, cys-AgNPs or AMNPs. The covalent linkage of MPcs to FA improved the water solubility of MPcs and allowed for singlet oxygen quantum yield determination in water. Asymmetric MPcs and their conjugates were found to have improved photochemical and photophysical properties compared to symmetrical MPcs and their conjugates. The heavy atom effect of AMNPs and AgNPs improved the triplet and singlet oxygen quantum yields of MPcs. MPcs and their conjugates (MPc-FA, MPc-AMNPs, MPc-AgNPs) were found to have lower in vitro dark cytotoxicity and higher photodynamic therapy (PDT) activity on MCF-7 breast cancer cells. The water soluble MPc-FA had better PDT activity when compared to MPc-AMNPs due to the active targeting of folic acid-folate binding on cancer cell surface. MPcs and MPc-AgNPs conjugates also showed excellent in vitro cytotoxicity on S. aureus under light irradiation compared to dark cytotoxicity. The photosensitizing properties of MPcs and their conjugates are demonstrated for the first time in this thesis, both on breast cancer cells (MCF-7) through photodynamic therapy and on microorganisms (S. aureus) through photodynamic antimicrobial chemotherapy.
- Full Text:
- Authors: Matlou, Gauta Gold
- Date: 2020
- Subjects: Cancer -- Photochemotherapy , Nanoparticles , Phthalocyanines , Anti-infective agents -- Therapeutic use , Photochemotherapy , Photochemistry
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166540 , vital:41377
- Description: This thesis presents on the synthesis and characterization of novel asymmetric and symmetrical metallophthalocyanines (MPcs) substituted with carboxylic acid functional groups and centrally metallated with zinc and indium. The MPcs are further covalently linked to cysteine capped silver nanoparticles (cys-AgNPs), amino functionalized magnetic nanoparticles (AMNPs) and folic acid (FA) through an amide bond between the carboxylic group of MPcs and the amino group of FA, cys-AgNPs or AMNPs. The covalent linkage of MPcs to FA improved the water solubility of MPcs and allowed for singlet oxygen quantum yield determination in water. Asymmetric MPcs and their conjugates were found to have improved photochemical and photophysical properties compared to symmetrical MPcs and their conjugates. The heavy atom effect of AMNPs and AgNPs improved the triplet and singlet oxygen quantum yields of MPcs. MPcs and their conjugates (MPc-FA, MPc-AMNPs, MPc-AgNPs) were found to have lower in vitro dark cytotoxicity and higher photodynamic therapy (PDT) activity on MCF-7 breast cancer cells. The water soluble MPc-FA had better PDT activity when compared to MPc-AMNPs due to the active targeting of folic acid-folate binding on cancer cell surface. MPcs and MPc-AgNPs conjugates also showed excellent in vitro cytotoxicity on S. aureus under light irradiation compared to dark cytotoxicity. The photosensitizing properties of MPcs and their conjugates are demonstrated for the first time in this thesis, both on breast cancer cells (MCF-7) through photodynamic therapy and on microorganisms (S. aureus) through photodynamic antimicrobial chemotherapy.
- Full Text:
Mineralogy, geochemistry and origin of the Neoproterozoic Xaudum iron-formation in Botswana
- Authors: Ntantiso, Mawande
- Date: 2020
- Subjects: Xaudum iron-formation , Iron ores -- Botswana , Formations (Geology) -- Botswana , Mineralogy -- Botswana , Paleoclimatology -- Proterozoic
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167211 , vital:41447
- Description: Banded iron-formations (BIF) formed in three different geological periods in the Earth’s history, namely the Archean, Paleoproterozoic and Neoproterozoic. Each of these periods has a corresponding index BIF type attributed to them. The oldest is the Archean Algoma-type BIF which is typically dominated by smaller-volume BIF deposits associated with volcanic rocks and greenstone belts. The next is the volumetrically far more abundant Superior-type BIF of the Paleoproterozoic lacking any obvious volcanic relation. The youngest BIFs were deposited after a hiatus of a billion years in the Neoproterozoic and are believed to be genetically linked to Marinoan ice-age. The global re-introduction and distribution of BIF in the Neoproterozoic highlights a shift in the Earth’s tectonics, climate, biosphere and ocean chemistry from the older Archean and Paleoproterozoic counterparts. Various models have been postulated by researchers in attempts to explain how Neoproterozoic iron-formations formed. In all the available models, the Snowball Earth Hypothesis initially proposed by Kirshvink (1992) is an overarching concept. In this study, four cores from the Neoproterozoic Xaudum iron-formation (XIF) in Ngamiland, northwest of Botswana, were sampled and analysed following a partnership between Postgraduate Research in Iron and Manganese Ore Resources (PRIMOR) and Tsodilo Resources Ltd. The study sets out to explore the mineralogy and chemistry of XIF in order to determine its origin, constrain the redox conditions in the paleo-basin, assess it in the context of other Neoproterozoic iron-formations and older Archean and Paleoproterozoic iron-formations, and inform metallurgical processing. The mineralogy of XIF consists of magnetite, quartz, amphibole, garnet, biotite and chlorite in decreasing abundance. This mineral assemblage is characteristic of medium grade metamorphosed iron-formations. Algoma and Superior-type BIFs which experienced late-diagenetic and very low-grade metamorphism have a complex mineral assemblage consisting of hematite, magnetite, quartz, and several carbonate (dolomite-ankerite series and siderite) and silicate phases (greenalite, riebeckite and stilpnomelane). The geochemical results show that XIF has higher Mn3O4 and Al2O3 average contents when compared to Algoma and Superior type BIF. The detrital components in XIF correlate with High Field Strength Elements (HFSE) suggesting increased delivery of siliciclastic material during deposition. This trend is comparable to other NIF deposits suggesting a global high input of siliciclastic material into Neoproterozoic paleodepositional environments. This trend is different from Archean and Paleoproterozoic BIF deposits which are close to pure chemical sediments lacking measurable detrital contributions. In the XIF, bulk-rock Mn3O4 and Al2O3 in drillcore SW have higher averages of 2.4 and 2.6 wt. % respectively, compared to the other three cores. The Mn3O4 shows a positive statistical relationship with Co, suggesting that Neoproterozoic oceans and atmosphere were possibly more oxic than in the Archean and Paleoproterozoic. The Mn3O4 shows an antithetic relationship with Fe2O3 suggesting that the paleobasin was chemically heterogeneous in terms of redox conditions, with Fe2O3 depositing presumably in deeper parts removed from a detrital source, and Mn3O4 depositing possibly more proximal to a paleo-shoreline in a shallower setting where there was higher delivery of siliciclastic material from the continent due to correspondingly higher Al2O3 and TiO2 contents. The REE patterns of XIF show positive-sloping trends of depletion in LREE and enrichment in HREE which resemble those of seawater. However, the REE slope becomes a lot flatter and resembles closer the signature of PAAS and adjacent diamictite facies, which agrees with the idea of high siliciclastic input in the paleobasin comparable to other NIF. XIF also appears to lack clear Ce or Eu anomalies. The lack of the former points to the oceans possibly not being oxic enough to drive the fractionation of Ce into Mn oxides like in the modern oceans, or that the Ce behaviour is obscured by the high siliciclastic input in XIF. Similarly, the lack of positive Eu anomaly shows a weak to absent hydrothermal signal into to modern shallow seawater where Fe and Si were sourced, or detritally derived REE contamination. Extensive weathering under hot and humid climate during glacial retreat is shown by the low K2O/Al2O3 ratios and high CIA values ranging from 80-99. Re-glaciation signifies the return of cold and arid and it is represented by high K2O/Al2O3 ratios and low CIA values ranging from 64-78. The previous genetic models of NIF by Klein (1993), Baldwin et al. (2012) and Lechte and Wallace (2015) provide an essential foundation for the development of a XIF genetic model. The genetic model of XIF proposes deposition on an open continental shelf characterized by a steady influx of detrital material. The seawater has been anoxic since the Paleoproterozoic and further induced by basin stagnation due to the ice covering the basin. Two overlapping oxidative stages are assumed for the precipitation of Fe and Mn across lateral redox gradients in the paleobasin. The exact oxidative pathways and mechanisms for the above processes remains unconstrained.
- Full Text:
- Authors: Ntantiso, Mawande
- Date: 2020
- Subjects: Xaudum iron-formation , Iron ores -- Botswana , Formations (Geology) -- Botswana , Mineralogy -- Botswana , Paleoclimatology -- Proterozoic
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167211 , vital:41447
- Description: Banded iron-formations (BIF) formed in three different geological periods in the Earth’s history, namely the Archean, Paleoproterozoic and Neoproterozoic. Each of these periods has a corresponding index BIF type attributed to them. The oldest is the Archean Algoma-type BIF which is typically dominated by smaller-volume BIF deposits associated with volcanic rocks and greenstone belts. The next is the volumetrically far more abundant Superior-type BIF of the Paleoproterozoic lacking any obvious volcanic relation. The youngest BIFs were deposited after a hiatus of a billion years in the Neoproterozoic and are believed to be genetically linked to Marinoan ice-age. The global re-introduction and distribution of BIF in the Neoproterozoic highlights a shift in the Earth’s tectonics, climate, biosphere and ocean chemistry from the older Archean and Paleoproterozoic counterparts. Various models have been postulated by researchers in attempts to explain how Neoproterozoic iron-formations formed. In all the available models, the Snowball Earth Hypothesis initially proposed by Kirshvink (1992) is an overarching concept. In this study, four cores from the Neoproterozoic Xaudum iron-formation (XIF) in Ngamiland, northwest of Botswana, were sampled and analysed following a partnership between Postgraduate Research in Iron and Manganese Ore Resources (PRIMOR) and Tsodilo Resources Ltd. The study sets out to explore the mineralogy and chemistry of XIF in order to determine its origin, constrain the redox conditions in the paleo-basin, assess it in the context of other Neoproterozoic iron-formations and older Archean and Paleoproterozoic iron-formations, and inform metallurgical processing. The mineralogy of XIF consists of magnetite, quartz, amphibole, garnet, biotite and chlorite in decreasing abundance. This mineral assemblage is characteristic of medium grade metamorphosed iron-formations. Algoma and Superior-type BIFs which experienced late-diagenetic and very low-grade metamorphism have a complex mineral assemblage consisting of hematite, magnetite, quartz, and several carbonate (dolomite-ankerite series and siderite) and silicate phases (greenalite, riebeckite and stilpnomelane). The geochemical results show that XIF has higher Mn3O4 and Al2O3 average contents when compared to Algoma and Superior type BIF. The detrital components in XIF correlate with High Field Strength Elements (HFSE) suggesting increased delivery of siliciclastic material during deposition. This trend is comparable to other NIF deposits suggesting a global high input of siliciclastic material into Neoproterozoic paleodepositional environments. This trend is different from Archean and Paleoproterozoic BIF deposits which are close to pure chemical sediments lacking measurable detrital contributions. In the XIF, bulk-rock Mn3O4 and Al2O3 in drillcore SW have higher averages of 2.4 and 2.6 wt. % respectively, compared to the other three cores. The Mn3O4 shows a positive statistical relationship with Co, suggesting that Neoproterozoic oceans and atmosphere were possibly more oxic than in the Archean and Paleoproterozoic. The Mn3O4 shows an antithetic relationship with Fe2O3 suggesting that the paleobasin was chemically heterogeneous in terms of redox conditions, with Fe2O3 depositing presumably in deeper parts removed from a detrital source, and Mn3O4 depositing possibly more proximal to a paleo-shoreline in a shallower setting where there was higher delivery of siliciclastic material from the continent due to correspondingly higher Al2O3 and TiO2 contents. The REE patterns of XIF show positive-sloping trends of depletion in LREE and enrichment in HREE which resemble those of seawater. However, the REE slope becomes a lot flatter and resembles closer the signature of PAAS and adjacent diamictite facies, which agrees with the idea of high siliciclastic input in the paleobasin comparable to other NIF. XIF also appears to lack clear Ce or Eu anomalies. The lack of the former points to the oceans possibly not being oxic enough to drive the fractionation of Ce into Mn oxides like in the modern oceans, or that the Ce behaviour is obscured by the high siliciclastic input in XIF. Similarly, the lack of positive Eu anomaly shows a weak to absent hydrothermal signal into to modern shallow seawater where Fe and Si were sourced, or detritally derived REE contamination. Extensive weathering under hot and humid climate during glacial retreat is shown by the low K2O/Al2O3 ratios and high CIA values ranging from 80-99. Re-glaciation signifies the return of cold and arid and it is represented by high K2O/Al2O3 ratios and low CIA values ranging from 64-78. The previous genetic models of NIF by Klein (1993), Baldwin et al. (2012) and Lechte and Wallace (2015) provide an essential foundation for the development of a XIF genetic model. The genetic model of XIF proposes deposition on an open continental shelf characterized by a steady influx of detrital material. The seawater has been anoxic since the Paleoproterozoic and further induced by basin stagnation due to the ice covering the basin. Two overlapping oxidative stages are assumed for the precipitation of Fe and Mn across lateral redox gradients in the paleobasin. The exact oxidative pathways and mechanisms for the above processes remains unconstrained.
- Full Text:
Mobilising the indigenous practice of making Oshikundu using an inquiry-based approach to support Grade 8 Life Science teachers in mediating learning of enzymes
- Shinana, Ester Ndakondja Lineekela
- Authors: Shinana, Ester Ndakondja Lineekela
- Date: 2020
- Subjects: Education, Secondary -- Namibia , Ethnoscience -- Namibia , Fermented beverages -- Namibia , Science -- Study and teaching (Secondary) -- Namibia , Enzymes -- Study and teaching (Secondary) -- Namibia , Ethnoscience -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/163615 , vital:41061
- Description: The Namibian curriculum encourages Life Science teachers to integrate indigenous knowledge into their science lessons. Additionally, it also encourages teachers to promote scientific inquiry in their science classrooms. However, it is not clear how Life Science teachers should go about doing this. As a result, science is taught in decontextualised ways and inquiry-based methods are neglected. It is against this background that this study sought to mobilise the indigenous practice of making oshikundu to mediate learning of enzymes and to promote inquiry-based methods. Essentially, an attempt was made to mediate the learning of enzymes through inquiry-based methods using, in particular, the Predict-Explain-Explore-Observe-Explain (PEEOE)approach.The approach entails learners making predictions and providing explanations for their predictions before they do their observations. The study employed a qualitative case study approach underpinned by an interpretive paradigm. It was conducted at two schools in the Omusati Region in Namibia and three Life Science teachers (two from one school and one from a different school) participated in this study.A variety of data gathering techniques such as document analysis, workshop discussions, participatory observation, and journal reflections were used to gather data and for triangulation purposes. A thematic approach to data analysis was adopted and data analysis and interpretation we redone inductively using Vygotsky’s socio-cultural theory and Shulman’s Pedagogical Content Kno Knowledge (TSPCK) model was used as the analytical framework to identify and improve the quality of Life Science teachers’ PCK in the topic of enzyme s in particular. Findings from this study revealed that some teachers had a narrow understanding of the concept of scientific inquiry, whereas some demonstrated a better understanding of the concept and how it is used in Life Science classrooms. The findings also revealed that the understanding of the teachers of an inquiry approach and how they understood science should be taught, further influenced their practice ; this was in addition to resource constraints. Furthermore, it was also established that some teachers did not include the concept of enzymes in their teaching. The workshop intervention equipped teachers with the knowledge on an inquiry approach and how to promote scientific inquiry skills in their classrooms. Likewise, the practical demonstration of making oshikundu also equipped the teachers with the knowledge of enzymes and together with the PEEOE approach, how to teach enzyme s using an inquiry approach. Teachers experienced challenges, as they had to use their creative, critical thinking and reasoning skills in order to identify the scientific concepts from the practical demonstration of oshikundu. The study suggests that there is a need for professional development programmes focusing specifically on supporting in-service science teachers’ understanding of inquiry and how to use the inquiry-based approach in their classrooms. Equally, the pre-service science teachers need such preparations during their training. Furthermore, the study also presents that there is a need to engage both pre-service and in-service teachers deeply with the new content of the Life Science syllabus.
- Full Text:
- Authors: Shinana, Ester Ndakondja Lineekela
- Date: 2020
- Subjects: Education, Secondary -- Namibia , Ethnoscience -- Namibia , Fermented beverages -- Namibia , Science -- Study and teaching (Secondary) -- Namibia , Enzymes -- Study and teaching (Secondary) -- Namibia , Ethnoscience -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/163615 , vital:41061
- Description: The Namibian curriculum encourages Life Science teachers to integrate indigenous knowledge into their science lessons. Additionally, it also encourages teachers to promote scientific inquiry in their science classrooms. However, it is not clear how Life Science teachers should go about doing this. As a result, science is taught in decontextualised ways and inquiry-based methods are neglected. It is against this background that this study sought to mobilise the indigenous practice of making oshikundu to mediate learning of enzymes and to promote inquiry-based methods. Essentially, an attempt was made to mediate the learning of enzymes through inquiry-based methods using, in particular, the Predict-Explain-Explore-Observe-Explain (PEEOE)approach.The approach entails learners making predictions and providing explanations for their predictions before they do their observations. The study employed a qualitative case study approach underpinned by an interpretive paradigm. It was conducted at two schools in the Omusati Region in Namibia and three Life Science teachers (two from one school and one from a different school) participated in this study.A variety of data gathering techniques such as document analysis, workshop discussions, participatory observation, and journal reflections were used to gather data and for triangulation purposes. A thematic approach to data analysis was adopted and data analysis and interpretation we redone inductively using Vygotsky’s socio-cultural theory and Shulman’s Pedagogical Content Kno Knowledge (TSPCK) model was used as the analytical framework to identify and improve the quality of Life Science teachers’ PCK in the topic of enzyme s in particular. Findings from this study revealed that some teachers had a narrow understanding of the concept of scientific inquiry, whereas some demonstrated a better understanding of the concept and how it is used in Life Science classrooms. The findings also revealed that the understanding of the teachers of an inquiry approach and how they understood science should be taught, further influenced their practice ; this was in addition to resource constraints. Furthermore, it was also established that some teachers did not include the concept of enzymes in their teaching. The workshop intervention equipped teachers with the knowledge on an inquiry approach and how to promote scientific inquiry skills in their classrooms. Likewise, the practical demonstration of making oshikundu also equipped the teachers with the knowledge of enzymes and together with the PEEOE approach, how to teach enzyme s using an inquiry approach. Teachers experienced challenges, as they had to use their creative, critical thinking and reasoning skills in order to identify the scientific concepts from the practical demonstration of oshikundu. The study suggests that there is a need for professional development programmes focusing specifically on supporting in-service science teachers’ understanding of inquiry and how to use the inquiry-based approach in their classrooms. Equally, the pre-service science teachers need such preparations during their training. Furthermore, the study also presents that there is a need to engage both pre-service and in-service teachers deeply with the new content of the Life Science syllabus.
- Full Text:
Molecular simulations of potential agents and targets of Alzheimer’s disease
- Authors: Carlisle, Tanya
- Date: 2020
- Subjects: Alzheimer's disease -- Treatment , Alzheimer's disease -- Molecular aspects , Amyloid beta-protein precurs , Amyloid beta-protein
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/140025 , vital:37825
- Description: The World Alzheimer Report statedin 2016 that approximately 46.8 million people were living with dementia and this figure is expected to triple by 2050. Alzheimer’s Disease was discovered to be a precursor to dementia in 1976 and since then efforts to understand Alzheimer’s have been prioritized. To date, there are very few effective forms of treatment for Alzheimer’s, many are known to offer only mild calming of the symptoms and have side effects such as diarrhea, nausea, loss of appetite and sleep disturbances. This has been due to lack of understanding on how Alzheimer’s is caused. With the two main hallmarks of the disease now being more understood it has opened the doorway into the discovery of new treatments for this disease. This study focuses on the hallmark involving the aggregation of the β-amyloid protein to form plaques surrounding the neurons of the brain. Copper, Zinc and Iron have also been found in high concentrations in and surrounding these plaques. This study focused on the screening of the South African Natural Compound database (SANCDB) to discover hits that have potential destabilizing action against the Beta-amyloid aggregate. If one of these compounds could prove to have destabilizing action on the aggregate it could open the doorway to new potential forms of treatment. Over 700 SANCDB compounds were docked, and the top hits were taken to molecular dynamics to further study the interactions of the compounds and the aggregate. However, the hits identified had strong binding to the aggregate causing it to become stable instead of the desired effect of destabilizing the structure. This information, however, does not rule out the possibility of these compounds preventing the formation of the aggregates. Further, interactions of copper with β-amyloid and copper were determined by solubilizing the aggregate and introducing copper ions in a dynamics simulation. Possible interactions between copper and the methionine residues were visualised.
- Full Text:
- Authors: Carlisle, Tanya
- Date: 2020
- Subjects: Alzheimer's disease -- Treatment , Alzheimer's disease -- Molecular aspects , Amyloid beta-protein precurs , Amyloid beta-protein
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/140025 , vital:37825
- Description: The World Alzheimer Report statedin 2016 that approximately 46.8 million people were living with dementia and this figure is expected to triple by 2050. Alzheimer’s Disease was discovered to be a precursor to dementia in 1976 and since then efforts to understand Alzheimer’s have been prioritized. To date, there are very few effective forms of treatment for Alzheimer’s, many are known to offer only mild calming of the symptoms and have side effects such as diarrhea, nausea, loss of appetite and sleep disturbances. This has been due to lack of understanding on how Alzheimer’s is caused. With the two main hallmarks of the disease now being more understood it has opened the doorway into the discovery of new treatments for this disease. This study focuses on the hallmark involving the aggregation of the β-amyloid protein to form plaques surrounding the neurons of the brain. Copper, Zinc and Iron have also been found in high concentrations in and surrounding these plaques. This study focused on the screening of the South African Natural Compound database (SANCDB) to discover hits that have potential destabilizing action against the Beta-amyloid aggregate. If one of these compounds could prove to have destabilizing action on the aggregate it could open the doorway to new potential forms of treatment. Over 700 SANCDB compounds were docked, and the top hits were taken to molecular dynamics to further study the interactions of the compounds and the aggregate. However, the hits identified had strong binding to the aggregate causing it to become stable instead of the desired effect of destabilizing the structure. This information, however, does not rule out the possibility of these compounds preventing the formation of the aggregates. Further, interactions of copper with β-amyloid and copper were determined by solubilizing the aggregate and introducing copper ions in a dynamics simulation. Possible interactions between copper and the methionine residues were visualised.
- Full Text:
Molecular simulations of potential agents and targets of Alzheimer’s disease
- Authors: Joli, Luxolo
- Date: 2020
- Subjects: Alzheimer's disease -- Chemotherapy , Alzheimer's disease -- Treatment , Ligands (Biochemistry) , Proteins -- Chemistry , Molecular dynamics -- Simulation methods
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146411 , vital:38523
- Description: Alzheimer's Disease (AD) is a neurodegenerative brain disorder that was first discovered in 1901 by Dr Aloïs Alzheimer and was later reported publicly in 1906. The German doctor had a 51-yearold woman patient called Auguste Deter, who was suffering from a rare brain disorder with early signs of memory loss and cognition. Alzheimer's Disease is the most common type of dementia that affects people with the age of 65 years and older. There is no single known cause of Alzheimer’s disease however, amyloid β-peptide (Aβ1–40/42) was found to be at the centre of AD pathogenesis and this connection was referred as “amyloid hypothesis”. It is suspected that an accumulation of amyloid β-peptide is a major contributor to neuronal dysfunction and degeneration. Alzheimer’s disease is complex and therefore, currently there is no medication available that treats the disease. However, there are approaches that focus on helping people maintain mental function, manage behavioral symptoms, and slow down the symptoms of disease. According to South Africa’s 2011 census, there are approximately 2.2 million people in South Africa with some form of dementia and therefore there is a need to find a treatment for the disease. This study aims to find agents and targets of Alzheimer’s Disease by using different computational techniques such as molecular modelling. The study will use compounds from the South African Compounds Database (SANCDB) and the following therapeutic targets α-, β- and γ-secretase, acetylcholinesterase, tau protein and neprilysin. A successful High-throughput Virtual Screening (HTVS) study to determine lead compounds was performed using a computational program called KNIME. Molecular docking was achieved with GLIDE as it allows for exhaustive ligand flexibility. The docking calculations were carried out using the high level of precision XP (extra precision) for enhanced docking accuracy. The binding affinities (docking scores) for the best bound ligands obtained from docking were in the order of -5 kcal/mol or less. The ligandSANC00370 was the best binding ligand against the protein 1J1C_B and had the best binding energy of -13.94 kcal/mol compared to others. The receptor-ligand complexes were analyzed using the interaction diagrams obtained from the Discovery Studio Visualizer and Maestro programs. Molecular Dynamics simulations were performed on the complexes obtained from docking to help in optimizing their interactions. The simulations were performed using the Desmond tool with the OPLS3 force field. 100 ns simulations were performed for six systems with the best docking score results epresenting each of the therapeutic targets and for the other complex systems, 50 ns simulations were performed. The Desmond simulations were analyzed using the Simulations Interaction Diagrams such as PL-RMSD, L-RMSF, P-RMSF, L-Torsions, P-SSE, LP-Contacts and L-Properties. Maestro was used to visualize the stability of the ligands in the active site during the simulation. All 13 Desmond simulations were successful however, there were 9 simulations which produced satisfactory results while the others were nsatisfactory. Based on the molecular docking and Molecular Dynamics results of this study, 9 potential targets and 6 potential agents were obtained successfully and can be studied further as therapeutics for Alzheimer’s Disease.
- Full Text:
- Authors: Joli, Luxolo
- Date: 2020
- Subjects: Alzheimer's disease -- Chemotherapy , Alzheimer's disease -- Treatment , Ligands (Biochemistry) , Proteins -- Chemistry , Molecular dynamics -- Simulation methods
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146411 , vital:38523
- Description: Alzheimer's Disease (AD) is a neurodegenerative brain disorder that was first discovered in 1901 by Dr Aloïs Alzheimer and was later reported publicly in 1906. The German doctor had a 51-yearold woman patient called Auguste Deter, who was suffering from a rare brain disorder with early signs of memory loss and cognition. Alzheimer's Disease is the most common type of dementia that affects people with the age of 65 years and older. There is no single known cause of Alzheimer’s disease however, amyloid β-peptide (Aβ1–40/42) was found to be at the centre of AD pathogenesis and this connection was referred as “amyloid hypothesis”. It is suspected that an accumulation of amyloid β-peptide is a major contributor to neuronal dysfunction and degeneration. Alzheimer’s disease is complex and therefore, currently there is no medication available that treats the disease. However, there are approaches that focus on helping people maintain mental function, manage behavioral symptoms, and slow down the symptoms of disease. According to South Africa’s 2011 census, there are approximately 2.2 million people in South Africa with some form of dementia and therefore there is a need to find a treatment for the disease. This study aims to find agents and targets of Alzheimer’s Disease by using different computational techniques such as molecular modelling. The study will use compounds from the South African Compounds Database (SANCDB) and the following therapeutic targets α-, β- and γ-secretase, acetylcholinesterase, tau protein and neprilysin. A successful High-throughput Virtual Screening (HTVS) study to determine lead compounds was performed using a computational program called KNIME. Molecular docking was achieved with GLIDE as it allows for exhaustive ligand flexibility. The docking calculations were carried out using the high level of precision XP (extra precision) for enhanced docking accuracy. The binding affinities (docking scores) for the best bound ligands obtained from docking were in the order of -5 kcal/mol or less. The ligandSANC00370 was the best binding ligand against the protein 1J1C_B and had the best binding energy of -13.94 kcal/mol compared to others. The receptor-ligand complexes were analyzed using the interaction diagrams obtained from the Discovery Studio Visualizer and Maestro programs. Molecular Dynamics simulations were performed on the complexes obtained from docking to help in optimizing their interactions. The simulations were performed using the Desmond tool with the OPLS3 force field. 100 ns simulations were performed for six systems with the best docking score results epresenting each of the therapeutic targets and for the other complex systems, 50 ns simulations were performed. The Desmond simulations were analyzed using the Simulations Interaction Diagrams such as PL-RMSD, L-RMSF, P-RMSF, L-Torsions, P-SSE, LP-Contacts and L-Properties. Maestro was used to visualize the stability of the ligands in the active site during the simulation. All 13 Desmond simulations were successful however, there were 9 simulations which produced satisfactory results while the others were nsatisfactory. Based on the molecular docking and Molecular Dynamics results of this study, 9 potential targets and 6 potential agents were obtained successfully and can be studied further as therapeutics for Alzheimer’s Disease.
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Multilingualism, innovation, and productivity: an examination of the impact of multilingualism in the workplace, with reference to the BRICS countries
- Authors: Leyne, Breda
- Date: 2020
- Subjects: Multilingualism -- BRIC countries , Bilingual communication in organizations , Second language acquisition , Language in the workplace , Diversity in the workplace , Communication in organizations , Intercultural communication , Labor productivity , Organizational behavior , Technological innovations , BRICS countries
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/148149 , vital:38714
- Description: This study examined whether the choice of language in the workplace affects personal and workplace productivity. The study has focussed on those working in countries which come under the BRICS grouping, Brazil, Russia, India and China and South Africa, as this provided a rich comparison of historical, economic and linguistic contexts. The research undertaken sought to explore the impact of prevailing language usage amongst employees of multi-national companies operating within the BRICS countries. With the assumption that these workforces will include multilingual individuals, the study set out to ascertain whether multilingualism has been recognised as a factor that might impact upon personal productivity or progress, either in a positive or negative fashion. The study set out to consider how language use may affect economic behaviour, firstly on a personal level and then to extrapolate this more widely into organisational productivity and innovation. This was set against background research into; theoretical perspectives on the acquisition of additional language, perceived benefits of bilingualism for individuals, studies of the management of language use with multinational corporations and relationships between language and economics. The conclusion reached is that multilingualism could have a beneficial impact on wider workforce productivity, and that it is not just a ‘language problem’ as it often seems to be treated. The final conclusion is that this may be something that should be more carefully considered by organisations in an increasingly global workplace. The researcher considers that multilingualism could be better employed as a workplace productivity metric, in a way that arguably it is not at present.
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- Authors: Leyne, Breda
- Date: 2020
- Subjects: Multilingualism -- BRIC countries , Bilingual communication in organizations , Second language acquisition , Language in the workplace , Diversity in the workplace , Communication in organizations , Intercultural communication , Labor productivity , Organizational behavior , Technological innovations , BRICS countries
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/148149 , vital:38714
- Description: This study examined whether the choice of language in the workplace affects personal and workplace productivity. The study has focussed on those working in countries which come under the BRICS grouping, Brazil, Russia, India and China and South Africa, as this provided a rich comparison of historical, economic and linguistic contexts. The research undertaken sought to explore the impact of prevailing language usage amongst employees of multi-national companies operating within the BRICS countries. With the assumption that these workforces will include multilingual individuals, the study set out to ascertain whether multilingualism has been recognised as a factor that might impact upon personal productivity or progress, either in a positive or negative fashion. The study set out to consider how language use may affect economic behaviour, firstly on a personal level and then to extrapolate this more widely into organisational productivity and innovation. This was set against background research into; theoretical perspectives on the acquisition of additional language, perceived benefits of bilingualism for individuals, studies of the management of language use with multinational corporations and relationships between language and economics. The conclusion reached is that multilingualism could have a beneficial impact on wider workforce productivity, and that it is not just a ‘language problem’ as it often seems to be treated. The final conclusion is that this may be something that should be more carefully considered by organisations in an increasingly global workplace. The researcher considers that multilingualism could be better employed as a workplace productivity metric, in a way that arguably it is not at present.
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My crazy character
- Authors: Sojini, Lungile
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/148217 , vital:38720
- Description: My thesis is a metafictional novella. I am interested in fictionalising the processes that writers use when they sit down to plan, write and publish novels. Metafiction interests me because it breaks from the traditional way of writing fiction, particularly with regards to the appearance of the author in the fictional world created. Devin Gribbons’s metafictional story (titled A Short Story), in the anthology of innovative writing, 30 Under 30, was my inspiration for developing the metafictional approach to novella length. Fyodor Dostoevsky’s Notes from Underground, Chief Fagunwa’s Forest of a Thousand Daemons, and Charles Bukowski’s autobiographical Ham on Rye, have for varying reasons, all influenced this writing.
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- Authors: Sojini, Lungile
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/148217 , vital:38720
- Description: My thesis is a metafictional novella. I am interested in fictionalising the processes that writers use when they sit down to plan, write and publish novels. Metafiction interests me because it breaks from the traditional way of writing fiction, particularly with regards to the appearance of the author in the fictional world created. Devin Gribbons’s metafictional story (titled A Short Story), in the anthology of innovative writing, 30 Under 30, was my inspiration for developing the metafictional approach to novella length. Fyodor Dostoevsky’s Notes from Underground, Chief Fagunwa’s Forest of a Thousand Daemons, and Charles Bukowski’s autobiographical Ham on Rye, have for varying reasons, all influenced this writing.
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Nine stories
- Authors: Dukas, Graham
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/147124 , vital:38595
- Description: Creative work portfolio.
- Full Text:
- Authors: Dukas, Graham
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/147124 , vital:38595
- Description: Creative work portfolio.
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Now that we have the land: analysing the experiences of land reform beneficiaries in the Makana Municipal District of the Eastern Cape, South Africa
- Authors: Msuthu, Simela Thuleka
- Date: 2020
- Subjects: Land reform , Sustainable development , Land reform -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land settlement -- Government policy -- South Africa -- Eastern Cape , Restitution -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/167551 , vital:41491
- Description: The “land question” in South Africa goes back more than a century to the 1913 Natives Land Act which facilitated the dispossession of African people from fertile land to arid homelands and congested townships. This mass dispossession of Africans from their land was accompanied by an array of legislation aimed at restricting their upward mobility, thus laying the foundations of structural inequality in South Africa. The advent of democracy in 1994 brought about a number of legislative reforms aimed at addressing the injustices that were imposed by the colonial and apartheid governments on the African people. At the forefront of these legislative efforts was the restoration of land to the original inhabitants of the country. Research indicates that, since 1994, the South African government has issued out land to different individuals and communities around the country in an attempt to address structural unemployment and poverty that plague the country. Using the Sustainable Livelihoods Theoretical framework, this study sought to examine the experiences of land reform beneficiaries in the Makana Municipal district of the Eastern Cape, in order to determine the extent to which the transfer of land to landless people has met the governments’ agenda to alleviate poverty and unemployment in the rural regions of South Africa. The findings in this study show that, successful land reform in South Africa is hindered mostly by two factors. Firstly, the inability of land beneficiaries to access quality education, skills training, finances and formal agricultural value chains. Secondly, land beneficiaries are further placed at a disadvantage by the poor quality of public services in their local municipalities and inconsistent post-settlement support from the state. The conclusion made in this study, is that the government has to be cognizant of the aforementioned structural barriers, when designing and rolling out land reform projects throughout the country. Failure to address these glaring structural barriers, will result in the creation of a peasant class of people living on underutilized land.
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- Authors: Msuthu, Simela Thuleka
- Date: 2020
- Subjects: Land reform , Sustainable development , Land reform -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land settlement -- Government policy -- South Africa -- Eastern Cape , Restitution -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/167551 , vital:41491
- Description: The “land question” in South Africa goes back more than a century to the 1913 Natives Land Act which facilitated the dispossession of African people from fertile land to arid homelands and congested townships. This mass dispossession of Africans from their land was accompanied by an array of legislation aimed at restricting their upward mobility, thus laying the foundations of structural inequality in South Africa. The advent of democracy in 1994 brought about a number of legislative reforms aimed at addressing the injustices that were imposed by the colonial and apartheid governments on the African people. At the forefront of these legislative efforts was the restoration of land to the original inhabitants of the country. Research indicates that, since 1994, the South African government has issued out land to different individuals and communities around the country in an attempt to address structural unemployment and poverty that plague the country. Using the Sustainable Livelihoods Theoretical framework, this study sought to examine the experiences of land reform beneficiaries in the Makana Municipal district of the Eastern Cape, in order to determine the extent to which the transfer of land to landless people has met the governments’ agenda to alleviate poverty and unemployment in the rural regions of South Africa. The findings in this study show that, successful land reform in South Africa is hindered mostly by two factors. Firstly, the inability of land beneficiaries to access quality education, skills training, finances and formal agricultural value chains. Secondly, land beneficiaries are further placed at a disadvantage by the poor quality of public services in their local municipalities and inconsistent post-settlement support from the state. The conclusion made in this study, is that the government has to be cognizant of the aforementioned structural barriers, when designing and rolling out land reform projects throughout the country. Failure to address these glaring structural barriers, will result in the creation of a peasant class of people living on underutilized land.
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Nutrient removal and biofuel potential of MaB-floc biomass from an integrated algal pond system treating domestic sewage
- Authors: Sibelo, Linda
- Date: 2020
- Subjects: Biomass energy , Waste products as fuel , Algal biofuels , Sewage -- Purification -- Nutrient removal
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/144955 , vital:38395
- Description: Integrated algal pond systems (IAPS) are a passive water treatment technology derived from the Oswald designed advanced integrated wastewater pond systems (AIWPS®) and effect wastewater treatment based on biological activity of microorganisms within the system, solar energy and gravity. The technology consists of an advanced facultative pond (AFP), a series of interconnected high rate algal oxidation ponds (HRAOP) and algal settling ponds. The symbiotic relationship between microalgae and bacteria facilitated by paddlewheel mixing of HRAOP results in the formation of biomass aggregates known as MaB-flocs. MaB-floc formation enhances nutrient abstraction, gravitational sedimentation and separation from water hence forming two product streams; recyclable water and biomass, both with valorisation potential. This work aimed to determine the suitability of MaB-floc biomass generated in the HRAOP of an IAPS treating domestic sewage as feedstock for biofuel production based on the content of carbohydrate and lipid. Nutrient removal efficiency, biomass productivity and bulk lipid and carbohydrate concentration were monitored for two consecutive three-month periods in the winter and summer seasons of 2018/19. Maximum removal efficiencies of nitrogen and phosphorus were determined as 71% and 75% respectively, demonstrating the efficiency of IAPS as a wastewater treatment technology. MaB-floc biomass productivity in winter and summer was 9.4 g/m2/d and 16.5 g/m2/d respectively indicating the heavy influence of seasonal temperature, possibly day length, and solar irradiation on biomass productivity in the HRAOP. Summer productivity was lower than the maximum theoretical productivity of 25 g/m2/d possibly due to photoinhibition of photosynthesis as well as grazing pressures caused by the proliferation of rotifers mainly of the Brachionus genus. MaB-floc biomass consistently contained higher amounts of carbohydrate than lipid despite the changes in species dominance from Scenedesmus sp. and Desmodesmus sp. in winter to Pediastrum sp. in summer. Variations in MaB-floc biomass carbohydrate content were linked to changes in nitrogen concentration, mainly in the form of nitrates. Lower nitrogen concentration significantly increased the carbohydrate content of MaB-floc biomass from 17.5 ± 0.15% to 33.5 ± 0.3 % recorded in summer. In winter, biomass carbohydrate increased from 18.3 ± 1.2% to 35.8 ± 0.3%.To induce accumulation of carbohydrates through nitrogen starvation, isolated microalgal species native to the HRAOPs of the IAPS at Institute for Environmental Biotechnology Rhodes University(EBRU) were used. The outcome from the laboratory studies showed that carbon partitioning within isolated strains could be altered from carbohydrate to lipid which is more energy-rich. Hence, exploring the biodiesel production option using HRAOP MaB-floc biomass, which had a lipid content ranging between 12.1 ± 0.64 % and 13.9 ± 0.5 %, would require a preconditioning step in the form of nitrogen starvation to enhance its lipid content. Overall, the outcome of outdoor monitoring studies on biomass biochemical composition indicated that HRAOPs operating under natural environmental conditions preferentially generated a biomass rich in carbohydrate. Therefore, anaerobic digestion may be a more viable option for HRAOP MaB-floc biomass because of the high carbohydrate levels ranging between 24.9 ± 0.6 % and 25.6 ± 1.3 % of the dry MaB-floc biomass weight. Despite the low biomass C/N ratio (7.1 to 7.8), the MaB-floc biomass can be anaerobically co-digested with a higher C/N ratio (24) substrate such as in-pond digester sludge, to improve methane yields calculated to be between 0.31 m3 CH4/ kg MaB-floc biomass and 0.33 m3 CH4/ kg MaB-floc biomass. Anaerobic digestion of biomass also produces CO2 which can be recovered and added to HRAOPs to enhance MaB-floc biomass productivity while lowering greenhouse gas emissions from a wastewater treatment plant. The digestate from the anaerobic process, which is rich in nitrogen and phosphorus can be used as a biofertiliser. Thus, a potential MaB-floc biomass biorefinery consisting of biogas and bio-fertiliser pathways can be established using IAPS treating sewage as the platform technology. IAPS is a system designed to operate in a way that is passive and without substantial environmental impact but technological innovations and a reduction in the size of the system are required to make the technology more acceptable.
- Full Text:
- Authors: Sibelo, Linda
- Date: 2020
- Subjects: Biomass energy , Waste products as fuel , Algal biofuels , Sewage -- Purification -- Nutrient removal
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/144955 , vital:38395
- Description: Integrated algal pond systems (IAPS) are a passive water treatment technology derived from the Oswald designed advanced integrated wastewater pond systems (AIWPS®) and effect wastewater treatment based on biological activity of microorganisms within the system, solar energy and gravity. The technology consists of an advanced facultative pond (AFP), a series of interconnected high rate algal oxidation ponds (HRAOP) and algal settling ponds. The symbiotic relationship between microalgae and bacteria facilitated by paddlewheel mixing of HRAOP results in the formation of biomass aggregates known as MaB-flocs. MaB-floc formation enhances nutrient abstraction, gravitational sedimentation and separation from water hence forming two product streams; recyclable water and biomass, both with valorisation potential. This work aimed to determine the suitability of MaB-floc biomass generated in the HRAOP of an IAPS treating domestic sewage as feedstock for biofuel production based on the content of carbohydrate and lipid. Nutrient removal efficiency, biomass productivity and bulk lipid and carbohydrate concentration were monitored for two consecutive three-month periods in the winter and summer seasons of 2018/19. Maximum removal efficiencies of nitrogen and phosphorus were determined as 71% and 75% respectively, demonstrating the efficiency of IAPS as a wastewater treatment technology. MaB-floc biomass productivity in winter and summer was 9.4 g/m2/d and 16.5 g/m2/d respectively indicating the heavy influence of seasonal temperature, possibly day length, and solar irradiation on biomass productivity in the HRAOP. Summer productivity was lower than the maximum theoretical productivity of 25 g/m2/d possibly due to photoinhibition of photosynthesis as well as grazing pressures caused by the proliferation of rotifers mainly of the Brachionus genus. MaB-floc biomass consistently contained higher amounts of carbohydrate than lipid despite the changes in species dominance from Scenedesmus sp. and Desmodesmus sp. in winter to Pediastrum sp. in summer. Variations in MaB-floc biomass carbohydrate content were linked to changes in nitrogen concentration, mainly in the form of nitrates. Lower nitrogen concentration significantly increased the carbohydrate content of MaB-floc biomass from 17.5 ± 0.15% to 33.5 ± 0.3 % recorded in summer. In winter, biomass carbohydrate increased from 18.3 ± 1.2% to 35.8 ± 0.3%.To induce accumulation of carbohydrates through nitrogen starvation, isolated microalgal species native to the HRAOPs of the IAPS at Institute for Environmental Biotechnology Rhodes University(EBRU) were used. The outcome from the laboratory studies showed that carbon partitioning within isolated strains could be altered from carbohydrate to lipid which is more energy-rich. Hence, exploring the biodiesel production option using HRAOP MaB-floc biomass, which had a lipid content ranging between 12.1 ± 0.64 % and 13.9 ± 0.5 %, would require a preconditioning step in the form of nitrogen starvation to enhance its lipid content. Overall, the outcome of outdoor monitoring studies on biomass biochemical composition indicated that HRAOPs operating under natural environmental conditions preferentially generated a biomass rich in carbohydrate. Therefore, anaerobic digestion may be a more viable option for HRAOP MaB-floc biomass because of the high carbohydrate levels ranging between 24.9 ± 0.6 % and 25.6 ± 1.3 % of the dry MaB-floc biomass weight. Despite the low biomass C/N ratio (7.1 to 7.8), the MaB-floc biomass can be anaerobically co-digested with a higher C/N ratio (24) substrate such as in-pond digester sludge, to improve methane yields calculated to be between 0.31 m3 CH4/ kg MaB-floc biomass and 0.33 m3 CH4/ kg MaB-floc biomass. Anaerobic digestion of biomass also produces CO2 which can be recovered and added to HRAOPs to enhance MaB-floc biomass productivity while lowering greenhouse gas emissions from a wastewater treatment plant. The digestate from the anaerobic process, which is rich in nitrogen and phosphorus can be used as a biofertiliser. Thus, a potential MaB-floc biomass biorefinery consisting of biogas and bio-fertiliser pathways can be established using IAPS treating sewage as the platform technology. IAPS is a system designed to operate in a way that is passive and without substantial environmental impact but technological innovations and a reduction in the size of the system are required to make the technology more acceptable.
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Observations of diffuse radio emission in the Abell 773 galaxy cluster
- Authors: Sichone, Gift L
- Date: 2020
- Subjects: Galaxies -- Clusters -- Observations , Radio astronomy -- Observations , Astrophysics -- South Africa , Westerbork Radio Telescope , A773 galaxy cluster , Astronomy -- Observations , Radio sources (Astronomy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/144945 , vital:38394
- Description: In this thesis, we present 18 and 21 cm observations of the A773 galaxy cluster observed with the Westerbork radio telescope. The final 18 and 21 cm images achieve a noise level of 0.018 mJy beam‾ 1 and 0.025 mJy beam-1 respectively. After subtracting the compact sources, the low resolution images show evidence of a radio halo at 18 cm, whereas its presence is more uncertain in the low resolution 21 cm images due the presence of residual sidelobes from bright sources. In the joint analysis of both frequencies, the radio halo has a 5.37 arcmin2 area with a 6.76 mJy flux density. Further observations and analysis are, however, required to fully characterize its properties.
- Full Text:
- Authors: Sichone, Gift L
- Date: 2020
- Subjects: Galaxies -- Clusters -- Observations , Radio astronomy -- Observations , Astrophysics -- South Africa , Westerbork Radio Telescope , A773 galaxy cluster , Astronomy -- Observations , Radio sources (Astronomy
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/144945 , vital:38394
- Description: In this thesis, we present 18 and 21 cm observations of the A773 galaxy cluster observed with the Westerbork radio telescope. The final 18 and 21 cm images achieve a noise level of 0.018 mJy beam‾ 1 and 0.025 mJy beam-1 respectively. After subtracting the compact sources, the low resolution images show evidence of a radio halo at 18 cm, whereas its presence is more uncertain in the low resolution 21 cm images due the presence of residual sidelobes from bright sources. In the joint analysis of both frequencies, the radio halo has a 5.37 arcmin2 area with a 6.76 mJy flux density. Further observations and analysis are, however, required to fully characterize its properties.
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Observations of diffuse radio emission in the Perseus Galaxy Cluster
- Authors: Mungwariri, Clemence
- Date: 2020
- Subjects: Galaxies -- Clusters , Radio sources (Astronomy) , Radio interferometers , Perseus Galaxy Cluster , Diffuse radio emission
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/143325 , vital:38233
- Description: In this thesis we analysed Westerbork observations of the Perseus Galaxy Cluster at 1380 MHz. Observations consist of two different pointings, covering a total of ∼ 0.5 square degrees, one including the known mini halo and the source 3C 84, the other centred on the source 3C 83.1 B. We obtained images with 83 μJy beam⁻¹ and 240 μJy beam⁻¹ noise rms for the two pointings respectively. We achieved a 60000 : 1 dynamic range in the image containing the bright 3C 84 source. We imaged the mini halo surrounding 3C 84 at high sensitivity, measuring its diameter to be ∼140 kpc and its power 4 x 10²⁴ W Hz⁻¹. Its morphology agrees quite well with that observed at 240 MHz (e.g. Gendron-Marsolais et al., 2017). We measured the flux density of 3C 84 to be 20.5 ± 0.4 Jy at the 2007 epoch, consistent with a factor of ∼2 increase since the 1960s.
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- Authors: Mungwariri, Clemence
- Date: 2020
- Subjects: Galaxies -- Clusters , Radio sources (Astronomy) , Radio interferometers , Perseus Galaxy Cluster , Diffuse radio emission
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/143325 , vital:38233
- Description: In this thesis we analysed Westerbork observations of the Perseus Galaxy Cluster at 1380 MHz. Observations consist of two different pointings, covering a total of ∼ 0.5 square degrees, one including the known mini halo and the source 3C 84, the other centred on the source 3C 83.1 B. We obtained images with 83 μJy beam⁻¹ and 240 μJy beam⁻¹ noise rms for the two pointings respectively. We achieved a 60000 : 1 dynamic range in the image containing the bright 3C 84 source. We imaged the mini halo surrounding 3C 84 at high sensitivity, measuring its diameter to be ∼140 kpc and its power 4 x 10²⁴ W Hz⁻¹. Its morphology agrees quite well with that observed at 240 MHz (e.g. Gendron-Marsolais et al., 2017). We measured the flux density of 3C 84 to be 20.5 ± 0.4 Jy at the 2007 epoch, consistent with a factor of ∼2 increase since the 1960s.
- Full Text: