Towards development of a malaria diagnostic: Generation, screening and validation of novel aptamers recognising Plasmodium falciparum lactate dehydrogenase
- Authors: Frith, Kelly-Anne
- Date: 2020
- Subjects: Plasmodium falciparum , Malaria -- Chemotherapy , Oligonucleotides , Lactate dehydrogenase , Biochemical markers , Systematic evolution of ligands through exponential enrichment (SELEX)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142247 , vital:38062
- Description: Malaria, caused by infection with the Plasmodium parasite, is one of the leading causes of death in under-developed countries. Early detection is crucial for the effective treatment of malaria, particularly in cases where infection is due to Plasmodium falciparum. There is, therefore, an enduring need for portable, sensitive, reliable, accurate, durable, self-validating and cost-effective techniques for the rapid detection of malaria. Moreover, there is a demand to distinguish between various infectious species causing malaria. Research in the area of malarial biomarkers has identified a unique, species-specific, epitope of P. falciparum lactate dehydrogenase (PfLDH), enhancing prospects for the development of diagnostics capable of identifying the species causing malarial infection. In recent years, improvements have been made towards the development of rapid diagnostic tests for detecting malarial biomarkers. Owing to their low cost, ease of labeling, and high thermal stability (relative to antibodies), the development and synthesis of aptamers that target the malarial lactate dehydrogenase represents one of the key innovations in the field of rapid diagnostics for malaria. This study explored the generation of aptamers that specifically target P. falciparum. Two sets of aptamers with diagnostically-supportive functions were generated independently, through parallel SELEX of recombinantly-expressed, full-length Plasmodium falciparum lactate dehydrogenase (rPfLDH), and an oligopeptide comprising the P. falciparum-specific epitope on lactate dehydrogenase (LDHp). The latter offers a promising solution for generating aptamers capable of binding with high specificity to P. falciparum. In this work, an rLDH class of aptamers was generated when SELEX was performed using the full-length rPfLDH protein as the target and the LDHp class of aptamers was generated when SELEX was performed using the oligopeptide LDHp as a target. Aptamers were successfully generated through the process of SELEX (systematic evolution of ligands through exponential enrichment) following the study and application of several optimisation steps, particularly during the amplification stage of SELEX. Optimisation steps included the study of improvements in PCR conditions; role of surfactants (Triton-X), modifying the PCR clean-up protocol; and agarose gel excision. Structurally-relevant moieties with particular consensus sequences (GGTAG and GGCG) were found in aptamers both reported here and previously published, confirming their importance in recognition of the target. Novel moieties particular to this work (ATTAT and poly-A stretches) were identified. Clades of consensus sequences were identified in both the rLDH and LDHp groups of aptamers, where sequences in the rLDH clade did not show preferential binding to rPfLDH while those in the LDHp clade (particularly LDHp 3 and 18) were able to recognise and bind only LDHp. Of the 19 sequences returned from the parallel SELEX procedures for rPfLDH (11 sequences) and LDHp (8 sequences), six rPfLDH and all eight LDHp sequences underwent preliminary screening and those with low responses eliminated. Of the eight LDHp-targeting aptamer sequences, five were preliminarily shown to bind to LDHp, whereas only two rPfLDH-targeting sequences were shown to bind to the target (rLDH 4 and 7). To this small selection of rPfLDH oligonucleotide sequences, two more (rLDH 1 and 15) were chosen for further study based on their sequences, secondary and predicted tertiary conformations. Sequences chosen for further study were therefore: rLDH 1, 4, 7 and 15 in the rLDH class, and LDHp 1, 3, 11, 14 and 18 in the LDHp class. Binding properties of the aptamers towards their targets were investigated using enzyme-linked oligonucleotide assays (ELONA), fluorophore-linked oligonucleotide assays (FLONA), electromobility shift assays (EMSA), surface plasmon resonance (SPR), and GelRed dissociation assays, while applications towards aptasensors were explored using electrochemical impedance spectroscopy (EIS) and fluorescent microscopy. Some inconsistencies were seen for specific aptamer to target binding interactions using specific techniques; however, generally, binding to the targets was observed across the techniques assessed. These varied responses demonstrate the need to screen and validate aptamers using a variety of techniques and platforms not necessarily specific for the proposed application. From the aptamer binding screening studies using ELONA, the most promising aptamers generated were identified as LDHp 11, rLDH 4, rLDH 7 and rLDH 15. Aptamer rLDH 4, which was generated against rPfLDH, exhibited preferential and specific binding to the lactate dehydrogenase from P. falciparum, over the recombinantly-expressed lactate dehydrogenase from Plasmodium vivax (rPvLDH), albeit with lowered responses compared to LDHp 11 in ELONA and EMSA studies. However, in kinetic ELONA studies rLDH 4 showed binding to both rPfLDH and rPvLDH. Aptamer rLDH 7 showed high affinity for rPfLDH and rPvLDH in kinetic studies using ELONA. However, screening studies with ELONA indicates that aptamer rLDH 7 may not be suitable for diagnostic tests in serum samples given its non-specific binding to human serum albumin (HSA). Aptamer rLDH 15 exhibited species specificity for rPfLDH in screening studies using ELONA but showed affinity towards rPvLDH (albeit lower relative to its affinity for rPfLDH) in kinetic studies using ELONA. LDHp 11, generated against the PfLDH peptide, showed a clear preference for rPfLDH when compared to rPvLDH and other control proteins, in both sets of ELONA studies conducted, as well as EMSA, thus possessing a strong ability to identify the presence of Plasmodium falciparum owing to its generation against the species-specific epitope. While LDHp 1 demonstrated binding to plasmodial LDH in a flow-through system (SPR), so reiterating ELONA responses, it did not perform well in the remaining methodologies. Aptamers rLDH 1 and 15 and LDHp 3, 14 and 18 exhibited a mixed set of results throughout the target protein screening analyses and were, thus, not considered for selective binding in P. falciparum parasite bodies. In studies aimed at exploring biosensor assemblies utilising the developed aptamers, both rLDH 4 and LDHp 11, along with rLDH 7, LDHp 1 and pL1, demonstrated in situ binding to the native PfLDH in fluorescent microscopy. LDHp 11 exhibited FITC-based fluorescence equivalent to the anti-rPfLDHp IgY antibody in confocal fluorescent microscopy indicating superior binding to the native PfLDH compared to the remaining aptamers. An examination of electrochemical impedance as a platform for a biosensor assembly did not, in these studies, exhibit the required sensitivity using physiologically relevant concentrations of analyte expected for pLDH following infection with Plasmodium spp. Malstat/LDH activity was explored for application in a colorimetric aptasensor. A decrease in both rPfLDH and rPvLDH activity was observed following incubation with the tested aptamers, but rLDH 1, rLDH 7 and LDHp 14 did not exhibit similar decreases in rPvLDH activity. Aptamers rLDH 1, 4 and 7 and LDHp 11 and 14 were, therefore, not selected as candidates for LDH capture in LDH activity-based diagnostic devices for P. falciparum. The decreases in pLDH activity in the presence of aptamers could hold promise as direct or antagonistic malaria therapeutic agents. Preliminary studies on the application of aptamers as malaria therapeutic agents, while of interest, should be viewed with due caution given the challenges of aptamers reaching the intracellular native plasmodial LDH hosted within the red blood cells. In conclusion, this work has shown the ability of the LDHp 11 aptamer, generated in these studies, to selectively bind rPfLDH over rPvLDH, and to bind to the native PfLDH in fluorescent microscopy, indicating that this aptamer holds promise as a biorecognition element in malaria biosensors and other diagnostic devices for the detection, and differentiation, of P. falciparum and P. vivax. The use of a species-specific epitope of P. falciparum as a target in aptamer generation paves the way for similar such studies aimed at generating aptamers with species selectivity for other Plasmodium species.
- Full Text:
- Date Issued: 2020
- Authors: Frith, Kelly-Anne
- Date: 2020
- Subjects: Plasmodium falciparum , Malaria -- Chemotherapy , Oligonucleotides , Lactate dehydrogenase , Biochemical markers , Systematic evolution of ligands through exponential enrichment (SELEX)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142247 , vital:38062
- Description: Malaria, caused by infection with the Plasmodium parasite, is one of the leading causes of death in under-developed countries. Early detection is crucial for the effective treatment of malaria, particularly in cases where infection is due to Plasmodium falciparum. There is, therefore, an enduring need for portable, sensitive, reliable, accurate, durable, self-validating and cost-effective techniques for the rapid detection of malaria. Moreover, there is a demand to distinguish between various infectious species causing malaria. Research in the area of malarial biomarkers has identified a unique, species-specific, epitope of P. falciparum lactate dehydrogenase (PfLDH), enhancing prospects for the development of diagnostics capable of identifying the species causing malarial infection. In recent years, improvements have been made towards the development of rapid diagnostic tests for detecting malarial biomarkers. Owing to their low cost, ease of labeling, and high thermal stability (relative to antibodies), the development and synthesis of aptamers that target the malarial lactate dehydrogenase represents one of the key innovations in the field of rapid diagnostics for malaria. This study explored the generation of aptamers that specifically target P. falciparum. Two sets of aptamers with diagnostically-supportive functions were generated independently, through parallel SELEX of recombinantly-expressed, full-length Plasmodium falciparum lactate dehydrogenase (rPfLDH), and an oligopeptide comprising the P. falciparum-specific epitope on lactate dehydrogenase (LDHp). The latter offers a promising solution for generating aptamers capable of binding with high specificity to P. falciparum. In this work, an rLDH class of aptamers was generated when SELEX was performed using the full-length rPfLDH protein as the target and the LDHp class of aptamers was generated when SELEX was performed using the oligopeptide LDHp as a target. Aptamers were successfully generated through the process of SELEX (systematic evolution of ligands through exponential enrichment) following the study and application of several optimisation steps, particularly during the amplification stage of SELEX. Optimisation steps included the study of improvements in PCR conditions; role of surfactants (Triton-X), modifying the PCR clean-up protocol; and agarose gel excision. Structurally-relevant moieties with particular consensus sequences (GGTAG and GGCG) were found in aptamers both reported here and previously published, confirming their importance in recognition of the target. Novel moieties particular to this work (ATTAT and poly-A stretches) were identified. Clades of consensus sequences were identified in both the rLDH and LDHp groups of aptamers, where sequences in the rLDH clade did not show preferential binding to rPfLDH while those in the LDHp clade (particularly LDHp 3 and 18) were able to recognise and bind only LDHp. Of the 19 sequences returned from the parallel SELEX procedures for rPfLDH (11 sequences) and LDHp (8 sequences), six rPfLDH and all eight LDHp sequences underwent preliminary screening and those with low responses eliminated. Of the eight LDHp-targeting aptamer sequences, five were preliminarily shown to bind to LDHp, whereas only two rPfLDH-targeting sequences were shown to bind to the target (rLDH 4 and 7). To this small selection of rPfLDH oligonucleotide sequences, two more (rLDH 1 and 15) were chosen for further study based on their sequences, secondary and predicted tertiary conformations. Sequences chosen for further study were therefore: rLDH 1, 4, 7 and 15 in the rLDH class, and LDHp 1, 3, 11, 14 and 18 in the LDHp class. Binding properties of the aptamers towards their targets were investigated using enzyme-linked oligonucleotide assays (ELONA), fluorophore-linked oligonucleotide assays (FLONA), electromobility shift assays (EMSA), surface plasmon resonance (SPR), and GelRed dissociation assays, while applications towards aptasensors were explored using electrochemical impedance spectroscopy (EIS) and fluorescent microscopy. Some inconsistencies were seen for specific aptamer to target binding interactions using specific techniques; however, generally, binding to the targets was observed across the techniques assessed. These varied responses demonstrate the need to screen and validate aptamers using a variety of techniques and platforms not necessarily specific for the proposed application. From the aptamer binding screening studies using ELONA, the most promising aptamers generated were identified as LDHp 11, rLDH 4, rLDH 7 and rLDH 15. Aptamer rLDH 4, which was generated against rPfLDH, exhibited preferential and specific binding to the lactate dehydrogenase from P. falciparum, over the recombinantly-expressed lactate dehydrogenase from Plasmodium vivax (rPvLDH), albeit with lowered responses compared to LDHp 11 in ELONA and EMSA studies. However, in kinetic ELONA studies rLDH 4 showed binding to both rPfLDH and rPvLDH. Aptamer rLDH 7 showed high affinity for rPfLDH and rPvLDH in kinetic studies using ELONA. However, screening studies with ELONA indicates that aptamer rLDH 7 may not be suitable for diagnostic tests in serum samples given its non-specific binding to human serum albumin (HSA). Aptamer rLDH 15 exhibited species specificity for rPfLDH in screening studies using ELONA but showed affinity towards rPvLDH (albeit lower relative to its affinity for rPfLDH) in kinetic studies using ELONA. LDHp 11, generated against the PfLDH peptide, showed a clear preference for rPfLDH when compared to rPvLDH and other control proteins, in both sets of ELONA studies conducted, as well as EMSA, thus possessing a strong ability to identify the presence of Plasmodium falciparum owing to its generation against the species-specific epitope. While LDHp 1 demonstrated binding to plasmodial LDH in a flow-through system (SPR), so reiterating ELONA responses, it did not perform well in the remaining methodologies. Aptamers rLDH 1 and 15 and LDHp 3, 14 and 18 exhibited a mixed set of results throughout the target protein screening analyses and were, thus, not considered for selective binding in P. falciparum parasite bodies. In studies aimed at exploring biosensor assemblies utilising the developed aptamers, both rLDH 4 and LDHp 11, along with rLDH 7, LDHp 1 and pL1, demonstrated in situ binding to the native PfLDH in fluorescent microscopy. LDHp 11 exhibited FITC-based fluorescence equivalent to the anti-rPfLDHp IgY antibody in confocal fluorescent microscopy indicating superior binding to the native PfLDH compared to the remaining aptamers. An examination of electrochemical impedance as a platform for a biosensor assembly did not, in these studies, exhibit the required sensitivity using physiologically relevant concentrations of analyte expected for pLDH following infection with Plasmodium spp. Malstat/LDH activity was explored for application in a colorimetric aptasensor. A decrease in both rPfLDH and rPvLDH activity was observed following incubation with the tested aptamers, but rLDH 1, rLDH 7 and LDHp 14 did not exhibit similar decreases in rPvLDH activity. Aptamers rLDH 1, 4 and 7 and LDHp 11 and 14 were, therefore, not selected as candidates for LDH capture in LDH activity-based diagnostic devices for P. falciparum. The decreases in pLDH activity in the presence of aptamers could hold promise as direct or antagonistic malaria therapeutic agents. Preliminary studies on the application of aptamers as malaria therapeutic agents, while of interest, should be viewed with due caution given the challenges of aptamers reaching the intracellular native plasmodial LDH hosted within the red blood cells. In conclusion, this work has shown the ability of the LDHp 11 aptamer, generated in these studies, to selectively bind rPfLDH over rPvLDH, and to bind to the native PfLDH in fluorescent microscopy, indicating that this aptamer holds promise as a biorecognition element in malaria biosensors and other diagnostic devices for the detection, and differentiation, of P. falciparum and P. vivax. The use of a species-specific epitope of P. falciparum as a target in aptamer generation paves the way for similar such studies aimed at generating aptamers with species selectivity for other Plasmodium species.
- Full Text:
- Date Issued: 2020
Introduction to Cecil Rhodes commemoration lecture 1981
- Authors: Henderson, Derek Scott
- Date: 1981-07-29
- Language: English
- Type: Text
- Identifier: vital:7435 , http://hdl.handle.net/10962/d1018312
- Full Text:
- Date Issued: 1981-07-29
- Authors: Henderson, Derek Scott
- Date: 1981-07-29
- Language: English
- Type: Text
- Identifier: vital:7435 , http://hdl.handle.net/10962/d1018312
- Full Text:
- Date Issued: 1981-07-29
A social and cultural history of Grahamstown, 1812 to c1845
- Authors: Marshall, Richard Graham
- Date: 2009
- Subjects: Cities and towns -- Growth -- South Africa -- Eastern Cape Community development, Urban -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- History -- 19th Century Grahamstown (South Africa) -- History -- 19th Century Grahamstown (South Africa) -- History -- Social aspects -- 19th Century Grahamstown (South Africa) -- Social conditions -- 19th Century Grahamstown (South Africa) -- Economic conditions -- 19th Century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2549 , http://hdl.handle.net/10962/d1002401
- Description: This thesis examines the development of Grahamstown from its inception in 1812 to the mid-1840s, paying particular attention to the social and cultural life of the town. It traces the economic development of the town from a military outpost to a thriving commercial settlement, noting the essential factor of the town's proximity to the Cape frontier in this process. The economic interaction between diverse groups in the town mirrors the social and cultural interaction which occurred between British settlers, Khoekhoe and Africans. The result of these interactions was the creation of a new, distinctively South African urban society and culture, despite the desire of the white settlers to reproduce a “typical” English environment in their new home. The conflict between attempts to anglicise the urban environment and the realities of Grahamstown's situation on a colonial frontier was reflected in the architecture and layout of the town. Attempts to recreate an English social environment also failed. New classes arose in the town in response to the economic opportunities available on the frontier. Although some settlers prospered, many did not, and the presence of an impoverished white working class undermines settler historians' picture of settler success and affluence. The poorest people in the town, though, were the increasing numbers of Khoekhoe and Africans who migrated from the surrounding countryside, and who were unequally incorporated into the urban community as a colonial labouring class. In response to these unique circumstances, white settlers in Grahamstown developed a powerful political and propaganda machine, which helped lay the foundations of a distinct settler identity in the eastern Cape.
- Full Text:
- Date Issued: 2009
- Authors: Marshall, Richard Graham
- Date: 2009
- Subjects: Cities and towns -- Growth -- South Africa -- Eastern Cape Community development, Urban -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- History -- 19th Century Grahamstown (South Africa) -- History -- 19th Century Grahamstown (South Africa) -- History -- Social aspects -- 19th Century Grahamstown (South Africa) -- Social conditions -- 19th Century Grahamstown (South Africa) -- Economic conditions -- 19th Century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2549 , http://hdl.handle.net/10962/d1002401
- Description: This thesis examines the development of Grahamstown from its inception in 1812 to the mid-1840s, paying particular attention to the social and cultural life of the town. It traces the economic development of the town from a military outpost to a thriving commercial settlement, noting the essential factor of the town's proximity to the Cape frontier in this process. The economic interaction between diverse groups in the town mirrors the social and cultural interaction which occurred between British settlers, Khoekhoe and Africans. The result of these interactions was the creation of a new, distinctively South African urban society and culture, despite the desire of the white settlers to reproduce a “typical” English environment in their new home. The conflict between attempts to anglicise the urban environment and the realities of Grahamstown's situation on a colonial frontier was reflected in the architecture and layout of the town. Attempts to recreate an English social environment also failed. New classes arose in the town in response to the economic opportunities available on the frontier. Although some settlers prospered, many did not, and the presence of an impoverished white working class undermines settler historians' picture of settler success and affluence. The poorest people in the town, though, were the increasing numbers of Khoekhoe and Africans who migrated from the surrounding countryside, and who were unequally incorporated into the urban community as a colonial labouring class. In response to these unique circumstances, white settlers in Grahamstown developed a powerful political and propaganda machine, which helped lay the foundations of a distinct settler identity in the eastern Cape.
- Full Text:
- Date Issued: 2009
An investigation into the relationship between adolescent parasuicide, depressive illness and associated risk factors
- Authors: Read, Gary Frank Hoyland
- Date: 1996
- Subjects: Youth -- Suicidal behavior , Depression in adolescence
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3116 , http://hdl.handle.net/10962/d1004615 , Youth -- Suicidal behavior , Depression in adolescence
- Description: This study aimed at investigating the relationship between adolescent parasuicide, depressive illness and associated risk factors. Reports worldwide indicate that suicidal behaviour in this age group has risen 150% over the past 20 years, whilst the rate for suicide in adults and the elderly has remained the same (Deykin et al, 1985; Neiger & Hopkins, 1988; Sudak, Ford & Rushforth, 1984a). In South Africa statistics confirm similar trends with regard to attempted and completed suicide. Statistics reveal that a high local incidence of adolescent suicide attempters are seen at psychiatric units. One pilot study recorded 187 adolescent suicide attempters during a three month period. This study was based on the hypothesis that the incidence of depressive illness in adolescent suicide attempters is higher than is generally accepted and that this condition often goes unrecognised and is misdiagnosed because it manifests differently with acting out behaviour and "masked" symptomatology. A random sample of suicide attempters between the ages of 13 - 25 who presented at C23 (psychiatric emergencies) Groote Schuur Hospital following a suicide attempt were assessed. 100 subjects were seen over a period of three months. The research procedure comprised a comprehensive assessment incorporating a semi-structured interview, self-report and objective rating scales for depression as well as instruments designed to assess the general health of each subject and their level of suicide intent. The depressive inventories used have been validated for use in this age group and were designed to elicit the associated features of adolescent depression. If warranted, a clinical diagnoses was given based on DSM 1V criteria. This diagnosis was substantiated by information from the research instruments which formed part of the assessment process. A high incidence of clinical disorders was diagnosed in the sample (86%). Depressive illness was found to be a significant risk factor for suicidal behaviour with 68% of the subjects suffering from an affective disorder and 21% reporting depressive symptoms. This study shows that the correlation between parasuicide and depressive illness is high enough to suggest that all suicidal behaviour in this age group should be taken seriously as parasuicide in itself is often a reliable indicator of an underlying depressive condition. Additional risk factors for adolescent parasuicide identified in this study correlated well with the findings of similar research studies. Psychiatric co-morbidity, especially substance use (42%) and cluster B personality factors (54%), were high and served to increase an individual's vulnerability to suicide risk. Psychosocial factors such as sexual abuse (28%) and physical abuse (37%) were also identified as high risk factors for adolescent suicidal behaviour. Individuals at risk for depression and suicidal behaviour typically came from broken homes which were disrupted and unsupportive. Family members were frequently abusing alcohol and 67% of the subjects reported the presence of psychiatric illness in the family. The preferred method of suicide attempt was an overdose (90%). These attempts were generally unplanned and impulsive with no disclosure prior to the event. Intent was usually high at the time of the act. It is only through identifying the risk factors specific to the developmental concerns of this age group and acknowledging the role of depressive illness in adolescent suicidal behaviour that effective preventative measures can be devised.
- Full Text:
- Date Issued: 1996
- Authors: Read, Gary Frank Hoyland
- Date: 1996
- Subjects: Youth -- Suicidal behavior , Depression in adolescence
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3116 , http://hdl.handle.net/10962/d1004615 , Youth -- Suicidal behavior , Depression in adolescence
- Description: This study aimed at investigating the relationship between adolescent parasuicide, depressive illness and associated risk factors. Reports worldwide indicate that suicidal behaviour in this age group has risen 150% over the past 20 years, whilst the rate for suicide in adults and the elderly has remained the same (Deykin et al, 1985; Neiger & Hopkins, 1988; Sudak, Ford & Rushforth, 1984a). In South Africa statistics confirm similar trends with regard to attempted and completed suicide. Statistics reveal that a high local incidence of adolescent suicide attempters are seen at psychiatric units. One pilot study recorded 187 adolescent suicide attempters during a three month period. This study was based on the hypothesis that the incidence of depressive illness in adolescent suicide attempters is higher than is generally accepted and that this condition often goes unrecognised and is misdiagnosed because it manifests differently with acting out behaviour and "masked" symptomatology. A random sample of suicide attempters between the ages of 13 - 25 who presented at C23 (psychiatric emergencies) Groote Schuur Hospital following a suicide attempt were assessed. 100 subjects were seen over a period of three months. The research procedure comprised a comprehensive assessment incorporating a semi-structured interview, self-report and objective rating scales for depression as well as instruments designed to assess the general health of each subject and their level of suicide intent. The depressive inventories used have been validated for use in this age group and were designed to elicit the associated features of adolescent depression. If warranted, a clinical diagnoses was given based on DSM 1V criteria. This diagnosis was substantiated by information from the research instruments which formed part of the assessment process. A high incidence of clinical disorders was diagnosed in the sample (86%). Depressive illness was found to be a significant risk factor for suicidal behaviour with 68% of the subjects suffering from an affective disorder and 21% reporting depressive symptoms. This study shows that the correlation between parasuicide and depressive illness is high enough to suggest that all suicidal behaviour in this age group should be taken seriously as parasuicide in itself is often a reliable indicator of an underlying depressive condition. Additional risk factors for adolescent parasuicide identified in this study correlated well with the findings of similar research studies. Psychiatric co-morbidity, especially substance use (42%) and cluster B personality factors (54%), were high and served to increase an individual's vulnerability to suicide risk. Psychosocial factors such as sexual abuse (28%) and physical abuse (37%) were also identified as high risk factors for adolescent suicidal behaviour. Individuals at risk for depression and suicidal behaviour typically came from broken homes which were disrupted and unsupportive. Family members were frequently abusing alcohol and 67% of the subjects reported the presence of psychiatric illness in the family. The preferred method of suicide attempt was an overdose (90%). These attempts were generally unplanned and impulsive with no disclosure prior to the event. Intent was usually high at the time of the act. It is only through identifying the risk factors specific to the developmental concerns of this age group and acknowledging the role of depressive illness in adolescent suicidal behaviour that effective preventative measures can be devised.
- Full Text:
- Date Issued: 1996
Overview and comparison of Besshi-type deposits ancient and recent
- Authors: Schoeman, Philo
- Date: 1996
- Subjects: Ore deposits -- Japan , Ore deposits -- Canada , Ore deposits -- Namibia , Ore deposits -- South Africa , Ore deposits
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4983 , http://hdl.handle.net/10962/d1005595 , Ore deposits -- Japan , Ore deposits -- Canada , Ore deposits -- Namibia , Ore deposits -- South Africa , Ore deposits
- Description: Besshi-type deposits range in age from early Proterozoic to early Tertiary, of which the largest number are late Proterozoic, early Palaeozoic or Mesozoic in age. No Archaean examples of Besshi-type deposits are known, probably due to insufficient availability of sialic crust for erosion and clastic marine sedimentation before the start of the Proterozoic. All Besshi-type deposits are contained within sequences of clastic sedimentary rock and intercalated basalts in a marine environment. The basalts and amphibolites are principally tholeiitic in composition. Besshi-type deposits characteristically form stratiform 1enses and sheet-like accumulations of semi-massive to massive sulphide. The main ore assemblage consists dominantly of pyrite and/or pyrrhotite with variable amounts of chalcopyrite, sphalerite and trace galena, arsenopyrite, gold and e1ectrum, barite being absent in general. The median Besshi-type deposit (n=75) contains 1.3 million tonnes (Mt) of massive sulphide with a Cu grade running at 1.43%. It is suggested that Besshi-type deposits form by both exhalative and synsedimentary replacement processes when considering geological features and comparisons with modern analogues in the Guaymas Basin, Middle Valley and Escanaba Trough. The currently forming metalliferous sediments in the Red Sea provide for a brine pool model explaining the lack of footwall feeder zones below sheet-like deposits. Where thick sulphide lenses are contained in some Besshi-type deposits, combinations of exhalative precipitation and sub-sea-floor replacement of permeable sediments and/or volcanic rocks, take place in the upper parts of submarine hydrothermal systems.
- Full Text:
- Date Issued: 1996
- Authors: Schoeman, Philo
- Date: 1996
- Subjects: Ore deposits -- Japan , Ore deposits -- Canada , Ore deposits -- Namibia , Ore deposits -- South Africa , Ore deposits
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4983 , http://hdl.handle.net/10962/d1005595 , Ore deposits -- Japan , Ore deposits -- Canada , Ore deposits -- Namibia , Ore deposits -- South Africa , Ore deposits
- Description: Besshi-type deposits range in age from early Proterozoic to early Tertiary, of which the largest number are late Proterozoic, early Palaeozoic or Mesozoic in age. No Archaean examples of Besshi-type deposits are known, probably due to insufficient availability of sialic crust for erosion and clastic marine sedimentation before the start of the Proterozoic. All Besshi-type deposits are contained within sequences of clastic sedimentary rock and intercalated basalts in a marine environment. The basalts and amphibolites are principally tholeiitic in composition. Besshi-type deposits characteristically form stratiform 1enses and sheet-like accumulations of semi-massive to massive sulphide. The main ore assemblage consists dominantly of pyrite and/or pyrrhotite with variable amounts of chalcopyrite, sphalerite and trace galena, arsenopyrite, gold and e1ectrum, barite being absent in general. The median Besshi-type deposit (n=75) contains 1.3 million tonnes (Mt) of massive sulphide with a Cu grade running at 1.43%. It is suggested that Besshi-type deposits form by both exhalative and synsedimentary replacement processes when considering geological features and comparisons with modern analogues in the Guaymas Basin, Middle Valley and Escanaba Trough. The currently forming metalliferous sediments in the Red Sea provide for a brine pool model explaining the lack of footwall feeder zones below sheet-like deposits. Where thick sulphide lenses are contained in some Besshi-type deposits, combinations of exhalative precipitation and sub-sea-floor replacement of permeable sediments and/or volcanic rocks, take place in the upper parts of submarine hydrothermal systems.
- Full Text:
- Date Issued: 1996
Historical perspectives and future directions for access to land, water and related ecosystem services in the Lower Sundays River Valley, South Africa: implications for human well being
- Authors: Chadzingwa, Karabo
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/442 , vital:19959
- Description: The legacy of South Africa’s history has facilitated unequal access to land and water resources. In the Lower Sundays River Valley (LSRV), a predominantly commercial farming area, differential access to land and water has impacted aspects of ecosystem service access and human well‐being for disenfranchised families over time. Despite the social, political and economic reform efforts in the past two decades, severe inertia towards efforts attempting to increase equitable access to land and water has been experienced. As a result, communities have mobilized and claimed their land from the government through the land restitution process. Based on a mixed‐methods approach, this research explores the ways in which access to land and water over time has influenced current levels of human well‐being among disenfranchised families. Provisioning and cultural ecosystem services were identified as key areas of loss as a result of forced evictions from land. Freedom of choice was a central and cross‐cutting theme regarding the ability to change levels of human well‐being. Although the loss of ecosystem services associated with land and water had an impact on households, the ecosystem services which are regarded as fundamental to human well‐being do not seem to have been lost. The study recommends the wide use of freedom of choice as an indicator for well‐being in the LSRV, as well as a consideration of subjective, objective and psychological measures of well‐being with regards to natural resources and ecosystem services access. Key agents in fostering desirable pathways toward equity and sustainability in the LSRV are identified with stakeholders as private businesses; inclusive governance; empowered and skilled individuals, as well as NGOs.
- Full Text:
- Date Issued: 2016
- Authors: Chadzingwa, Karabo
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/442 , vital:19959
- Description: The legacy of South Africa’s history has facilitated unequal access to land and water resources. In the Lower Sundays River Valley (LSRV), a predominantly commercial farming area, differential access to land and water has impacted aspects of ecosystem service access and human well‐being for disenfranchised families over time. Despite the social, political and economic reform efforts in the past two decades, severe inertia towards efforts attempting to increase equitable access to land and water has been experienced. As a result, communities have mobilized and claimed their land from the government through the land restitution process. Based on a mixed‐methods approach, this research explores the ways in which access to land and water over time has influenced current levels of human well‐being among disenfranchised families. Provisioning and cultural ecosystem services were identified as key areas of loss as a result of forced evictions from land. Freedom of choice was a central and cross‐cutting theme regarding the ability to change levels of human well‐being. Although the loss of ecosystem services associated with land and water had an impact on households, the ecosystem services which are regarded as fundamental to human well‐being do not seem to have been lost. The study recommends the wide use of freedom of choice as an indicator for well‐being in the LSRV, as well as a consideration of subjective, objective and psychological measures of well‐being with regards to natural resources and ecosystem services access. Key agents in fostering desirable pathways toward equity and sustainability in the LSRV are identified with stakeholders as private businesses; inclusive governance; empowered and skilled individuals, as well as NGOs.
- Full Text:
- Date Issued: 2016
Inflation threshold and nonlinearity: implications for inflation targeting in South Africa
- Authors: Morar, Derwina
- Date: 2011
- Subjects: Inflation targeting -- South Africa Interest rates -- Effect of inflation on -- South Africa Monetary policy -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:984 , http://hdl.handle.net/10962/d1002718
- Description: Following many other central banks around the world, the South African Reserve Bank has adopted inflation targeting as its monetary policy framework. The aim of this is to achieve low levels of inflation in order to attain price stability thereby promoting growth. In South Africa, the chosen band to target is 3%–6%. This has been criticised by many trade unions who are calling for the abandonment of inflation targeting. Despite targeting 3%–6%, it is not known whether this is the optimal inflation range for South Africa. Therefore, the aim of this study is to determine the inflation threshold level for South Africa using quarterly data for the period 1983 to 2010. The first section determines whether or not there is a long-run relationship between inflation and growth using the Johansen cointegration method. Exogeneity tests determine the causality between these variables. Vector error correction models are estimated if cointegration is found. The second part determines the threshold level of inflation using the method of conditional least squares. The inflation level that maximises the R-squared value and minimises the residual sum of squares gives an indication of the threshold level. The third part of the study determines whether or not inflation volatility has a significant impact on growth. The first part established that there is long-run comovement between inflation and growth.The causality is bidirectional with both variables being endogenous.Findings regarding the threshold level show that the current inflation targeting band of 3%–6% may be extended up to 9.5%. In addition, the range of inflation from 5.5% to 6.5% promotes economic growth in South Africa. Finally, the evidence suggests that inflation volatility does not have a significant impact on economic growth and the focus of policy should be directed towards the level of inflation as has been the case.
- Full Text:
- Date Issued: 2011
- Authors: Morar, Derwina
- Date: 2011
- Subjects: Inflation targeting -- South Africa Interest rates -- Effect of inflation on -- South Africa Monetary policy -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:984 , http://hdl.handle.net/10962/d1002718
- Description: Following many other central banks around the world, the South African Reserve Bank has adopted inflation targeting as its monetary policy framework. The aim of this is to achieve low levels of inflation in order to attain price stability thereby promoting growth. In South Africa, the chosen band to target is 3%–6%. This has been criticised by many trade unions who are calling for the abandonment of inflation targeting. Despite targeting 3%–6%, it is not known whether this is the optimal inflation range for South Africa. Therefore, the aim of this study is to determine the inflation threshold level for South Africa using quarterly data for the period 1983 to 2010. The first section determines whether or not there is a long-run relationship between inflation and growth using the Johansen cointegration method. Exogeneity tests determine the causality between these variables. Vector error correction models are estimated if cointegration is found. The second part determines the threshold level of inflation using the method of conditional least squares. The inflation level that maximises the R-squared value and minimises the residual sum of squares gives an indication of the threshold level. The third part of the study determines whether or not inflation volatility has a significant impact on growth. The first part established that there is long-run comovement between inflation and growth.The causality is bidirectional with both variables being endogenous.Findings regarding the threshold level show that the current inflation targeting band of 3%–6% may be extended up to 9.5%. In addition, the range of inflation from 5.5% to 6.5% promotes economic growth in South Africa. Finally, the evidence suggests that inflation volatility does not have a significant impact on economic growth and the focus of policy should be directed towards the level of inflation as has been the case.
- Full Text:
- Date Issued: 2011
Service quality importance-performance analysis as a strategic tool for management : the exploration of key customer satisfaction drivers in a South African electricity utility
- Authors: MacColl, Barry
- Date: 2004
- Subjects: Eskom (Firm) Electric power distribution -- Customer services -- South Africa -- Eastern Cape Electric power distribution -- South Africa -- Eastern Cape -- Quality control Customer services -- Quality control Customer services -- Rating of -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:806 , http://hdl.handle.net/10962/d1006972
- Description: This research was initiated due to declining customer satisfaction indices in the Southern region of Eskom, an electricity utility in South Africa. Given the link between customer satisfaction and purchase intentions, the sustainability of the business is at stake. The validity of the current MaxiCare survey tool is questioned and explored, as is the congruence of management and customers' perceptions regarding the key service quality constructs in the industry. The study's objective was to provide management with a reliable and valid customer satisfaction survey instrument as an alternate to the existing tool and to use the knowledge gained through the research process to recommend improvement strategies aimed at closing specific satisfaction gaps identified. The research was performed in two stages; firstly, semistructured interviews with customers and management to gain an understanding of the most important satisfaction dimensions. These influenced the design of a survey instrument based largely on the SERVPERF tool with the inclusion of importance ratings per item in the second stage. The quantitative survey results were used to assess the reliability and validity of the research and to suggest areas for future work. The results show that communication, quality of supply, assurance and price are uppermost in the consumer's mind. Tangibles are not significant and the inclusion of empathy is inconclusive. Management and customer perceptions at a macro level are closely aligned, however the two populations are not in agreement as to the underlying micro considerations. Similarly, the MaxiCare instrument is found to be valid as a macro indicator but lacks sufficient detail to be useful as a strategic tool and needs to be supplemented with additional sources of market information. The survey instrument used in the second phase is both descriptive and reliable but the number of factors it measures, the mix of items and the inclusion of the 'importance' dimension need further refinement to improve its validity. Future revisions of the tool will provide management with specific information that allows them to focus improvement strategies on disgruntled customers and their key service issues.
- Full Text:
- Date Issued: 2004
- Authors: MacColl, Barry
- Date: 2004
- Subjects: Eskom (Firm) Electric power distribution -- Customer services -- South Africa -- Eastern Cape Electric power distribution -- South Africa -- Eastern Cape -- Quality control Customer services -- Quality control Customer services -- Rating of -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:806 , http://hdl.handle.net/10962/d1006972
- Description: This research was initiated due to declining customer satisfaction indices in the Southern region of Eskom, an electricity utility in South Africa. Given the link between customer satisfaction and purchase intentions, the sustainability of the business is at stake. The validity of the current MaxiCare survey tool is questioned and explored, as is the congruence of management and customers' perceptions regarding the key service quality constructs in the industry. The study's objective was to provide management with a reliable and valid customer satisfaction survey instrument as an alternate to the existing tool and to use the knowledge gained through the research process to recommend improvement strategies aimed at closing specific satisfaction gaps identified. The research was performed in two stages; firstly, semistructured interviews with customers and management to gain an understanding of the most important satisfaction dimensions. These influenced the design of a survey instrument based largely on the SERVPERF tool with the inclusion of importance ratings per item in the second stage. The quantitative survey results were used to assess the reliability and validity of the research and to suggest areas for future work. The results show that communication, quality of supply, assurance and price are uppermost in the consumer's mind. Tangibles are not significant and the inclusion of empathy is inconclusive. Management and customer perceptions at a macro level are closely aligned, however the two populations are not in agreement as to the underlying micro considerations. Similarly, the MaxiCare instrument is found to be valid as a macro indicator but lacks sufficient detail to be useful as a strategic tool and needs to be supplemented with additional sources of market information. The survey instrument used in the second phase is both descriptive and reliable but the number of factors it measures, the mix of items and the inclusion of the 'importance' dimension need further refinement to improve its validity. Future revisions of the tool will provide management with specific information that allows them to focus improvement strategies on disgruntled customers and their key service issues.
- Full Text:
- Date Issued: 2004
Distribution of iron-titanium oxides in the vanadiferous main magnetite seam of the upper zone : Northern limb, Bushveld complex
- Authors: Gwatinetsa, Demand
- Date: 2014
- Subjects: Igneous rocks -- South Africa -- Bushveld Complex , Sulfide minerals -- South Africa -- Bushveld Complex , Vanadium -- South Africa -- Bushveld Complex , Titanium dioxide -- South Africa -- Bushveld Complex , Ferric oxide -- South Africa -- Bushveld Complex , Geology -- South Africa -- Bushveld Complex , Mineralogy -- South Africa -- Bushveld Complex , Mines and mineral resources -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5063 , http://hdl.handle.net/10962/d1013281
- Description: The main magnetite seam of the Upper Zone of the Rustenburg Layered Suite (SACS, 1980) on the Bushveld Complex is known to host the world‘s largest vanadium bearing titaniferous iron ores. The vanadiferous titanomagnetites, contain vanadium in sufficient concentrations (1.2 - 2.2 per cent V₂O₅) to be considered as resources and vanadium has been mined historically by a number of companies among them Anglo-American, Highveld Steel and Vanadium and VanMag Resources as well as currently by Evraz Highveld Steel and Vanadium Limited of South Africa. The titanomagnetites contain iron ore in the form of magnetite and titanium with concentrations averaging 50-75 per cent FeO and 12-21 per cent TiO₂. The titaniferous iron ores have been historically dismissed as a source of iron and titanium, due to the known difficulties of using iron ore with high titania content in blast furnaces. The economic potential for the extractability of the titaniferous magnetites lies in the capacity of the ores to be separated into iron rich and titanium rich concentrates usually through, crushing, grinding and magnetic separation. The separatability of iron oxides and titanium oxides, is dependent on the nature in which the titanium oxide occurs, with granular ilmenite being the most favourable since it can be separated from magnetite via magnetic separation. Titanium that occurs as finely exsolved lamellae or as iron-titanium oxides with low titania content such as ulvospinel render the potential recoverability of titanium poor. The Upper Zone vanadiferous titanomagnetites contain titanium in various forms varying from discrete granular ilmenite to finely exsolved lamellae as well as occurring as part of the minerals ulvospinel (Fe₂TiO₄) and titanomagnetite (a solid solution series between ulvospinel and magnetite) . Discrete ilmenite constitutes between 3-5 per cent by volume of the massive titanomagnetite ores, and between 5-10 per cent by volume of the magnetite-plagioclase cumulates with more than 50 per cent opaque oxide minerals. The purpose of this research was to investigate the mineralogical setting and distribution of the iron and titanium oxides within the magnetitite layers from top to bottom as well as spatially along a strike length of 2 000m to determine the potential for the titanium to be extracted from the titanomagnetite ores. The titanomagnetites of the Upper Zone of the Bushveld Complex with particular reference to the Northern Limb where this research was conducted contains titanium oxides as discrete ilmenite grains but in low concentrations whose potential for separate economic extraction will be challenging. The highest concentration of titanium in the magnetite ores is not contained in the granular ilmenite, but rather in ulvospinel and titanomagnetite as illustrated by the marked higher concentration of TiO₂ in the massive ores which contain less granular ilmenite in comparison to the disseminated ores which contain 3 to 8 percentage points higher granular ilmenite than the massive ores. On the scale of the main magnetite seam, the TiO₂ content increases with increasing stratigraphic height from being completely absent in the footwall anorthosite. The V₂2O₅ content also increases with stratigraphic height except for in one of the 3 boreholes where it drops with increasing height. The decrease or increase patterns are repeated in every seam. The titanomagnetites of the main magnetite seam display a variety of textures from coarse granular magnetite and ilmenite, to trellis ilmenite lamellae, intergranular ilmenite and magnesian spinels and fine exsolution lamellae of ulvospinel and ferro-magnesian spinels parallel to the magnetite cleavage. The bottom contact of the main magnetite seam is very sharp and there is no titanium or vanadium in the footwall barely 10cm below the contact. Chromium is present in the bottom of the 4 layers that constitute the main magnetite seam and it upwards decreases rapidly. In boreholes P21 and P55, there are slight reversals in the TiO₂ and V₂O₅ content towards the top of the magnetite seams.
- Full Text:
- Date Issued: 2014
- Authors: Gwatinetsa, Demand
- Date: 2014
- Subjects: Igneous rocks -- South Africa -- Bushveld Complex , Sulfide minerals -- South Africa -- Bushveld Complex , Vanadium -- South Africa -- Bushveld Complex , Titanium dioxide -- South Africa -- Bushveld Complex , Ferric oxide -- South Africa -- Bushveld Complex , Geology -- South Africa -- Bushveld Complex , Mineralogy -- South Africa -- Bushveld Complex , Mines and mineral resources -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5063 , http://hdl.handle.net/10962/d1013281
- Description: The main magnetite seam of the Upper Zone of the Rustenburg Layered Suite (SACS, 1980) on the Bushveld Complex is known to host the world‘s largest vanadium bearing titaniferous iron ores. The vanadiferous titanomagnetites, contain vanadium in sufficient concentrations (1.2 - 2.2 per cent V₂O₅) to be considered as resources and vanadium has been mined historically by a number of companies among them Anglo-American, Highveld Steel and Vanadium and VanMag Resources as well as currently by Evraz Highveld Steel and Vanadium Limited of South Africa. The titanomagnetites contain iron ore in the form of magnetite and titanium with concentrations averaging 50-75 per cent FeO and 12-21 per cent TiO₂. The titaniferous iron ores have been historically dismissed as a source of iron and titanium, due to the known difficulties of using iron ore with high titania content in blast furnaces. The economic potential for the extractability of the titaniferous magnetites lies in the capacity of the ores to be separated into iron rich and titanium rich concentrates usually through, crushing, grinding and magnetic separation. The separatability of iron oxides and titanium oxides, is dependent on the nature in which the titanium oxide occurs, with granular ilmenite being the most favourable since it can be separated from magnetite via magnetic separation. Titanium that occurs as finely exsolved lamellae or as iron-titanium oxides with low titania content such as ulvospinel render the potential recoverability of titanium poor. The Upper Zone vanadiferous titanomagnetites contain titanium in various forms varying from discrete granular ilmenite to finely exsolved lamellae as well as occurring as part of the minerals ulvospinel (Fe₂TiO₄) and titanomagnetite (a solid solution series between ulvospinel and magnetite) . Discrete ilmenite constitutes between 3-5 per cent by volume of the massive titanomagnetite ores, and between 5-10 per cent by volume of the magnetite-plagioclase cumulates with more than 50 per cent opaque oxide minerals. The purpose of this research was to investigate the mineralogical setting and distribution of the iron and titanium oxides within the magnetitite layers from top to bottom as well as spatially along a strike length of 2 000m to determine the potential for the titanium to be extracted from the titanomagnetite ores. The titanomagnetites of the Upper Zone of the Bushveld Complex with particular reference to the Northern Limb where this research was conducted contains titanium oxides as discrete ilmenite grains but in low concentrations whose potential for separate economic extraction will be challenging. The highest concentration of titanium in the magnetite ores is not contained in the granular ilmenite, but rather in ulvospinel and titanomagnetite as illustrated by the marked higher concentration of TiO₂ in the massive ores which contain less granular ilmenite in comparison to the disseminated ores which contain 3 to 8 percentage points higher granular ilmenite than the massive ores. On the scale of the main magnetite seam, the TiO₂ content increases with increasing stratigraphic height from being completely absent in the footwall anorthosite. The V₂2O₅ content also increases with stratigraphic height except for in one of the 3 boreholes where it drops with increasing height. The decrease or increase patterns are repeated in every seam. The titanomagnetites of the main magnetite seam display a variety of textures from coarse granular magnetite and ilmenite, to trellis ilmenite lamellae, intergranular ilmenite and magnesian spinels and fine exsolution lamellae of ulvospinel and ferro-magnesian spinels parallel to the magnetite cleavage. The bottom contact of the main magnetite seam is very sharp and there is no titanium or vanadium in the footwall barely 10cm below the contact. Chromium is present in the bottom of the 4 layers that constitute the main magnetite seam and it upwards decreases rapidly. In boreholes P21 and P55, there are slight reversals in the TiO₂ and V₂O₅ content towards the top of the magnetite seams.
- Full Text:
- Date Issued: 2014
The gastric morphology of the white-tailed rat Mystromys Albicaudatus (A.Smith 1834) and preliminary investigation of its digestive processes
- Authors: Maddock, Anthony Hamilton
- Date: 1982
- Subjects: Rats -- Physiology Digestion
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5603 , http://hdl.handle.net/10962/d1002053
- Description: The gastric morphology of the white-tailed rat M. albicaudatus - was described in detail. The bilocular hemiglandular stomach consists of a papillated corpus, non-glandular PGP and glandular antrum. The antrum contains cardiac, fundic and PJ loric glands (suggesting limited glandular reduction during gastric evolution) while the FCE and PGP are lined with orthokeratin. The corpal papillae, which increase surface area for microbial attachment, have undergone a different type of keratinisation called physiological hyperkeratosis. Streptococci, Lactobacilli and unidentified anaerobic bacilli (which colonise papillary microhabitats) are autochthonous in the stomach of M. albicaudatus but P. vulgaris and Ps. flourescens are probably autochthonous. Early gastric development is innate but the rapid development of PB into papillae between 15 and 17 days suggests the presence of allogenic growth stimuli: possibly mechanical abrasion by solid food, low chalone concentration in the papillary basal cells and the influence of the APB. Stimulation by VFA presence, however, is unlikely due to the low concentration of these acids in the stomach (Summary, p. 225)
- Full Text:
- Date Issued: 1982
- Authors: Maddock, Anthony Hamilton
- Date: 1982
- Subjects: Rats -- Physiology Digestion
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5603 , http://hdl.handle.net/10962/d1002053
- Description: The gastric morphology of the white-tailed rat M. albicaudatus - was described in detail. The bilocular hemiglandular stomach consists of a papillated corpus, non-glandular PGP and glandular antrum. The antrum contains cardiac, fundic and PJ loric glands (suggesting limited glandular reduction during gastric evolution) while the FCE and PGP are lined with orthokeratin. The corpal papillae, which increase surface area for microbial attachment, have undergone a different type of keratinisation called physiological hyperkeratosis. Streptococci, Lactobacilli and unidentified anaerobic bacilli (which colonise papillary microhabitats) are autochthonous in the stomach of M. albicaudatus but P. vulgaris and Ps. flourescens are probably autochthonous. Early gastric development is innate but the rapid development of PB into papillae between 15 and 17 days suggests the presence of allogenic growth stimuli: possibly mechanical abrasion by solid food, low chalone concentration in the papillary basal cells and the influence of the APB. Stimulation by VFA presence, however, is unlikely due to the low concentration of these acids in the stomach (Summary, p. 225)
- Full Text:
- Date Issued: 1982
A survey of customer satisfaction, expectations and perceptions as a measure of service quality in SANBS
- Authors: Mququ, Mpumzi H
- Date: 2006
- Subjects: South African National Blood Service Consumer satisfaction Customer services -- Quality control Customer services -- Rating of Blood banks -- Quality control -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:767 , http://hdl.handle.net/10962/d1003888
- Description: The purpose of the study is to evaluate the service quality that the SANBS provides to its customers, by measuring customers’ perceptions and their expectations of service quality provided by the supplier of blood transfusion services. The organization that is used for this study is the South African National Blood Service (SANBS). Specifically the study seeks to: 1. Determine the extent to which customers are satisfied or not satisfied with the service they receive from the SANBS using the ten-dimensional format of SERVQUAL model, modified to the specific service quality requirements of the blood transfusion service industry. 2. Establish customers’ perceptions of the service they receive using a multiple-item scale (SERVQUAL) for measuring consumer perceptions of service quality. 3. Establish customers’ expectations of the service, and compare them to their perceptions of the service they currently receive. The comparison is made along each service quality dimension, across different parts of same service on a geographical basis, and across different customer groups on a customer category (or type) basis. 4. Recommend implementation of appropriate service quality performance improvement procedures where necessary. Study design and methods: The data for the study came from the SANBS’ customer perception and expectation survey conducted in 2005. Questionnaires were sent out to hospitals that use products and services provided by the SANBS in the Eastern Cape and KwaZulu-Natal Provinces of South Africa. The questionnaire was based on the multiple-item SERVQUAL model for measuring consumer perceptions of service quality, modified and tailored to specific service quality requirements of the blood transfusion service industry. Questionnaires were sent out to 113 (69.3%) hospitals out of a total of 163 blood-utilizing hospitals in the two provinces. Of the 113 hospitals, 92 (81.4%) responded, with questionnaires rendered unusable. The final sample size is 88 and is included in the final study database. The data is analyzed by comparing different parts of the service on a geographical basis namely KwaZulu-Natal and Eastern Cape zones. The data is also analyzed by comparing different customer groups namely the Rural State Hospitals, the Urban State Hospitals and Private Hospitals. Results: The result confirms the research (alternative) hypothesis (H1 : μ1 ≠ μ2), and rejects Ho. The overall expectations ratings are higher than the perceptions ratings, and the KwaZulu-Natal expectations ratings are higher than the Eastern Cape ratings. The expectations of private hospitals and rural state hospitals have a higher rating than that of urban state hospitals and the perceptions of private and urban state hospitals have a higher rating than that of rural state hospitals. The largest service quality gap is the accessibility dimension which relates specifically to approachability and ease with which customers can access staff at different levels of the organization by e-mail, and includes accessing of knowledgeable blood bank personnel and medical staff of SANBS, but may also relate to the distance of hospitals from the nearest blood bank, all of which are situated in urban state hospitals. The mean difference for accessibility is the highest followed by the understanding customer mean difference. The mean differences for the other dimension categories are significantly less than that of the largest two dimensions, but not significantly different amongst themselves. The mean difference for rural state hospitals is the largest followed by private hospitals and urban state hospitals. The mean difference for rural state hospitals is greater than that for urban state hospitals in both zones, but the mean difference for private hospitals is greater in KwaZulu-Natal than in the Eastern Cape. The dimension means of differences for rural state hospitals are greater than that for urban state hospitals. According to the correlations between expectations and perceptions for different dimensions, there is a weak or no linear relationship between expectations and perceptions. Conclusion: This empirical study supports the literature on the provision of service quality, and concludes that there is a statistically significant difference or gap between the services offered by the SANBS as perceived by its customers, and the expectations of its customers. The study substantiates the need for management of blood transfusion services to take into account customer perceptions of service quality and their expectations, and upon identification of gaps, to implement appropriate service quality improvement processes, rather than take a one sided view of their (SANBS’) own perception of service quality.
- Full Text:
- Date Issued: 2006
- Authors: Mququ, Mpumzi H
- Date: 2006
- Subjects: South African National Blood Service Consumer satisfaction Customer services -- Quality control Customer services -- Rating of Blood banks -- Quality control -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:767 , http://hdl.handle.net/10962/d1003888
- Description: The purpose of the study is to evaluate the service quality that the SANBS provides to its customers, by measuring customers’ perceptions and their expectations of service quality provided by the supplier of blood transfusion services. The organization that is used for this study is the South African National Blood Service (SANBS). Specifically the study seeks to: 1. Determine the extent to which customers are satisfied or not satisfied with the service they receive from the SANBS using the ten-dimensional format of SERVQUAL model, modified to the specific service quality requirements of the blood transfusion service industry. 2. Establish customers’ perceptions of the service they receive using a multiple-item scale (SERVQUAL) for measuring consumer perceptions of service quality. 3. Establish customers’ expectations of the service, and compare them to their perceptions of the service they currently receive. The comparison is made along each service quality dimension, across different parts of same service on a geographical basis, and across different customer groups on a customer category (or type) basis. 4. Recommend implementation of appropriate service quality performance improvement procedures where necessary. Study design and methods: The data for the study came from the SANBS’ customer perception and expectation survey conducted in 2005. Questionnaires were sent out to hospitals that use products and services provided by the SANBS in the Eastern Cape and KwaZulu-Natal Provinces of South Africa. The questionnaire was based on the multiple-item SERVQUAL model for measuring consumer perceptions of service quality, modified and tailored to specific service quality requirements of the blood transfusion service industry. Questionnaires were sent out to 113 (69.3%) hospitals out of a total of 163 blood-utilizing hospitals in the two provinces. Of the 113 hospitals, 92 (81.4%) responded, with questionnaires rendered unusable. The final sample size is 88 and is included in the final study database. The data is analyzed by comparing different parts of the service on a geographical basis namely KwaZulu-Natal and Eastern Cape zones. The data is also analyzed by comparing different customer groups namely the Rural State Hospitals, the Urban State Hospitals and Private Hospitals. Results: The result confirms the research (alternative) hypothesis (H1 : μ1 ≠ μ2), and rejects Ho. The overall expectations ratings are higher than the perceptions ratings, and the KwaZulu-Natal expectations ratings are higher than the Eastern Cape ratings. The expectations of private hospitals and rural state hospitals have a higher rating than that of urban state hospitals and the perceptions of private and urban state hospitals have a higher rating than that of rural state hospitals. The largest service quality gap is the accessibility dimension which relates specifically to approachability and ease with which customers can access staff at different levels of the organization by e-mail, and includes accessing of knowledgeable blood bank personnel and medical staff of SANBS, but may also relate to the distance of hospitals from the nearest blood bank, all of which are situated in urban state hospitals. The mean difference for accessibility is the highest followed by the understanding customer mean difference. The mean differences for the other dimension categories are significantly less than that of the largest two dimensions, but not significantly different amongst themselves. The mean difference for rural state hospitals is the largest followed by private hospitals and urban state hospitals. The mean difference for rural state hospitals is greater than that for urban state hospitals in both zones, but the mean difference for private hospitals is greater in KwaZulu-Natal than in the Eastern Cape. The dimension means of differences for rural state hospitals are greater than that for urban state hospitals. According to the correlations between expectations and perceptions for different dimensions, there is a weak or no linear relationship between expectations and perceptions. Conclusion: This empirical study supports the literature on the provision of service quality, and concludes that there is a statistically significant difference or gap between the services offered by the SANBS as perceived by its customers, and the expectations of its customers. The study substantiates the need for management of blood transfusion services to take into account customer perceptions of service quality and their expectations, and upon identification of gaps, to implement appropriate service quality improvement processes, rather than take a one sided view of their (SANBS’) own perception of service quality.
- Full Text:
- Date Issued: 2006
Obedient daughter, silenced witch: the hysteric in Freudian psychoanalysis
- Authors: Roux, Catharina
- Date: 1989
- Subjects: Freud, Sigmund, 1856-1939 -- Criticism and interpretation , Hysteria , Psychoanalysis , Seduction
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3117 , http://hdl.handle.net/10962/d1004637 , Freud, Sigmund, 1856-1939 -- Criticism and interpretation , Hysteria , Psychoanalysis , Seduction
- Description: This study explores the theoretical consequences of Freud's renunciation of the seduction theory. The dissertation defends the thesis that the seduction theory was shaped as much by Freud's adherence to the nomonological model as by the empirical evidence of child sexual abuse. A renunciation of the seduction theory was inevitable, not because the accounts of the daughters were lies, but because the methodology was inappropriate. The nomonological model obscured the emotional structure of the nuclear family in which the structure itself, through which sexuality emerged, directed the girl's entrance into womanhood and caused the woman's dis-ease. Freud's methodology forced him to isolate an event as cause of an illness and to attribute the event to an agent. The universal perversity of the Victorian father thus became the central theme around which an explanation of a female disease was built. When this theme became theoretically untenable, Freud renounced the seduction theory and, still using the nomonological model, built up the construct of the Oedipus complex in which the father was vindicated. In order to exonerate the father, the transactions through which the child's libido developed were represented as originating in inherent tendencies. As a result, the hierarchical nature of the interaction between parent and child was distorted, and this led to the formulation of the distinction between real events and fantasies as a basic premise on which the difference between the pleasure principle and the reality principle rests. This formulation gave rise to the sharp duality between fantasy and reality which eventually compelled him to separate psychic reality and social reality. The theoretical structure built on this duality could not but fuse hysteria, masochism and "normal" femininity into an explanation of the female state, and obscure the essential social relations between men and women which were structured in terms of dominance and submission. The thesis traces the journey from the perverted father as cause of a female disease, hysteria, to the theoretical conjunction of masochism and hysteria. It comes to the conclusion that Freud's model is unable to explain the self-mutilation of the hysteric; nor is it capable of explaining the hysteric's refusal to participate in the circuit of symbolic exchanges which constituted Victorian society. The study further attempts to understand hysteria in terms of the complex interlacing of fact and fantasy and tries to show that fantasy was rooted in the facts of Victorian culture.
- Full Text:
- Date Issued: 1989
- Authors: Roux, Catharina
- Date: 1989
- Subjects: Freud, Sigmund, 1856-1939 -- Criticism and interpretation , Hysteria , Psychoanalysis , Seduction
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3117 , http://hdl.handle.net/10962/d1004637 , Freud, Sigmund, 1856-1939 -- Criticism and interpretation , Hysteria , Psychoanalysis , Seduction
- Description: This study explores the theoretical consequences of Freud's renunciation of the seduction theory. The dissertation defends the thesis that the seduction theory was shaped as much by Freud's adherence to the nomonological model as by the empirical evidence of child sexual abuse. A renunciation of the seduction theory was inevitable, not because the accounts of the daughters were lies, but because the methodology was inappropriate. The nomonological model obscured the emotional structure of the nuclear family in which the structure itself, through which sexuality emerged, directed the girl's entrance into womanhood and caused the woman's dis-ease. Freud's methodology forced him to isolate an event as cause of an illness and to attribute the event to an agent. The universal perversity of the Victorian father thus became the central theme around which an explanation of a female disease was built. When this theme became theoretically untenable, Freud renounced the seduction theory and, still using the nomonological model, built up the construct of the Oedipus complex in which the father was vindicated. In order to exonerate the father, the transactions through which the child's libido developed were represented as originating in inherent tendencies. As a result, the hierarchical nature of the interaction between parent and child was distorted, and this led to the formulation of the distinction between real events and fantasies as a basic premise on which the difference between the pleasure principle and the reality principle rests. This formulation gave rise to the sharp duality between fantasy and reality which eventually compelled him to separate psychic reality and social reality. The theoretical structure built on this duality could not but fuse hysteria, masochism and "normal" femininity into an explanation of the female state, and obscure the essential social relations between men and women which were structured in terms of dominance and submission. The thesis traces the journey from the perverted father as cause of a female disease, hysteria, to the theoretical conjunction of masochism and hysteria. It comes to the conclusion that Freud's model is unable to explain the self-mutilation of the hysteric; nor is it capable of explaining the hysteric's refusal to participate in the circuit of symbolic exchanges which constituted Victorian society. The study further attempts to understand hysteria in terms of the complex interlacing of fact and fantasy and tries to show that fantasy was rooted in the facts of Victorian culture.
- Full Text:
- Date Issued: 1989
An investigation into the nature and extent of erosion and sedimentation in the Maqalika Dam catchment, Maseru
- Authors: Ntsaba, 'Mankone 'Mabataung
- Date: 1990
- Subjects: Erosion -- Lesotho Sedimentation and deposition -- Lesotho Land use -- Lesotho -- History River sediments -- Lesotho
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4799 , http://hdl.handle.net/10962/d1001899
- Description: The study investigates the nature and extent of erosion and deposition in the Maqalika catchment, Maseru. Components of the study include (i) the re-construction of erosion and land use history in the catchment from 1961 to 1985, (li) determination of dominant factors or combinations of factors responsible for the observed erosion distribution at each date, (iii) the identification and evaluation of erosion and deposition features, and their spatial and temporal variations, and (iv) identification of socia-economic problems associated with observed erosion and deposition. Methods employed for the re-construction of erosion and land use history include the use of sequential aerial photography of 1961, 1979 and 1985, orthophoto maps and review of literature from past studies. It has been possible to map erosion and land use for the three time periods pinpointing areas of major change. Results are presented in map form showing the spatial distribution of each erosion class and each land use category. It was however not possible to derive any meaningful relationship between erosion distribution and land use, on the aforementioned maps. The only observation made from the comparison of the maps is that erosion degree and distribution sometimes changes with land use, while land use sometimes changes in response to erosion. Major land use changes are the conversion of agricultural land to urban land use, and grazing land. Due to the mnlti-dimensional nature of soil erosion, hand 'actor analysis was employed to determine which factors or combinations of factors were dominant at each date. Despite the extensive research on the various factors affecting erosion such as those used for the USLE and SLEMSA there is a growing uncertainty as to which factors are more important to erosion. Soil erodibility has been found to be a component of the major controlling factor combinations in all three periods under study. At each date erodibility combined with a number of other factors determined the observed erosion distribution. As suggested by Mosley (1980), Cambell (1985) and Coleman and Scatena (1986) sediment from a catchment is derived principally from spatially limited portions of the catchment. Likewise eroded sediment becomes deposited in spatially limited areas with special characteristics which encourage deposition. Aerial photographic survey aided by ground survey and oblique photographs were employed to identify sediment sources and sinks within the catchment. Some sediment sources are fIxed such as gully floors and sides, while some change location from time to time such as construction sites. An evaluation of portions of the catchment for their ability to supply and deliver sediment has shown that the most eroded areas are not the most active sediment sources. Sediment yield is limited by either supply or transport. Sediment yield was estimated using reservoir survey data which indicate that there is a high rate of soil loss from the catchment. One flaw of this method as a measure of soil loss is that it treats the measured sediment yield as if it were contributed uniformly from the basin. This method however affords the researcher to estimate minimum erosion rates, taking into account that large amounts of sediment are stored at various places within the catchment. The possible socio-economic consequences of erosion and deposition have been identified. These include loss of cropland, destruction of roads and building sites which require methods of reclamation, sedimentation of small reservoirs and ponds, and the formation of gully bottom fills which are potential sediment sources. Conservation measures presently applied in the catchment are assessed and found to be irrelavant to the present erosion problem. Data from the reservoir survey revealed that the estimated rate of soil loss is more important to on-site erosion damage than to off-site damage in the form of the sedimentation of Maqalika reservoir. Appropriate conservation measures such as those suggested by Amimoto (1981) would be relevant to the study area, however the main constraint in their implementation would be lack of legislation and the absence of a sound land use policy. It is therefore concluded that the present land use situation which does not take into consideration the physical constraints of the catchment is partly responsible for accelarated erosion in the catchment.
- Full Text:
- Date Issued: 1990
- Authors: Ntsaba, 'Mankone 'Mabataung
- Date: 1990
- Subjects: Erosion -- Lesotho Sedimentation and deposition -- Lesotho Land use -- Lesotho -- History River sediments -- Lesotho
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4799 , http://hdl.handle.net/10962/d1001899
- Description: The study investigates the nature and extent of erosion and deposition in the Maqalika catchment, Maseru. Components of the study include (i) the re-construction of erosion and land use history in the catchment from 1961 to 1985, (li) determination of dominant factors or combinations of factors responsible for the observed erosion distribution at each date, (iii) the identification and evaluation of erosion and deposition features, and their spatial and temporal variations, and (iv) identification of socia-economic problems associated with observed erosion and deposition. Methods employed for the re-construction of erosion and land use history include the use of sequential aerial photography of 1961, 1979 and 1985, orthophoto maps and review of literature from past studies. It has been possible to map erosion and land use for the three time periods pinpointing areas of major change. Results are presented in map form showing the spatial distribution of each erosion class and each land use category. It was however not possible to derive any meaningful relationship between erosion distribution and land use, on the aforementioned maps. The only observation made from the comparison of the maps is that erosion degree and distribution sometimes changes with land use, while land use sometimes changes in response to erosion. Major land use changes are the conversion of agricultural land to urban land use, and grazing land. Due to the mnlti-dimensional nature of soil erosion, hand 'actor analysis was employed to determine which factors or combinations of factors were dominant at each date. Despite the extensive research on the various factors affecting erosion such as those used for the USLE and SLEMSA there is a growing uncertainty as to which factors are more important to erosion. Soil erodibility has been found to be a component of the major controlling factor combinations in all three periods under study. At each date erodibility combined with a number of other factors determined the observed erosion distribution. As suggested by Mosley (1980), Cambell (1985) and Coleman and Scatena (1986) sediment from a catchment is derived principally from spatially limited portions of the catchment. Likewise eroded sediment becomes deposited in spatially limited areas with special characteristics which encourage deposition. Aerial photographic survey aided by ground survey and oblique photographs were employed to identify sediment sources and sinks within the catchment. Some sediment sources are fIxed such as gully floors and sides, while some change location from time to time such as construction sites. An evaluation of portions of the catchment for their ability to supply and deliver sediment has shown that the most eroded areas are not the most active sediment sources. Sediment yield is limited by either supply or transport. Sediment yield was estimated using reservoir survey data which indicate that there is a high rate of soil loss from the catchment. One flaw of this method as a measure of soil loss is that it treats the measured sediment yield as if it were contributed uniformly from the basin. This method however affords the researcher to estimate minimum erosion rates, taking into account that large amounts of sediment are stored at various places within the catchment. The possible socio-economic consequences of erosion and deposition have been identified. These include loss of cropland, destruction of roads and building sites which require methods of reclamation, sedimentation of small reservoirs and ponds, and the formation of gully bottom fills which are potential sediment sources. Conservation measures presently applied in the catchment are assessed and found to be irrelavant to the present erosion problem. Data from the reservoir survey revealed that the estimated rate of soil loss is more important to on-site erosion damage than to off-site damage in the form of the sedimentation of Maqalika reservoir. Appropriate conservation measures such as those suggested by Amimoto (1981) would be relevant to the study area, however the main constraint in their implementation would be lack of legislation and the absence of a sound land use policy. It is therefore concluded that the present land use situation which does not take into consideration the physical constraints of the catchment is partly responsible for accelarated erosion in the catchment.
- Full Text:
- Date Issued: 1990
Observation and processing of 2.3 GHz radio astronomy survey data
- Authors: Jonas, Justin Leonard
- Date: 1983 , 2013-04-15
- Subjects: Radio astronomy , Southern sky (Astronomy)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5505 , http://hdl.handle.net/10962/d1007280 , Radio astronomy , Southern sky (Astronomy)
- Description: The results of the second part of the Rhodes University Southern Sky Survey at 2.3GHz are presented. The area surveyed extends from 12hOO to 22hOO right ascension between declinations -63º and -24º. The observation technique and data reduction processes are analyzed. Digital data processing techniques used to enhance and display the data are dicussed. The results show that the Galactic emission extends as far as 40º latitude. Filamentary and loop-like structures are found superimposed on this general emission. Many of these features are unidentified as yet. A large region of emission is found to coincide with the Sco-Cen stellar association. A lower limit for the ionizing flux from the stars in the association is derived. All of the non-confused extragalactic sources with flux densities greater than O.5Jy are listed. The flux densities of these sources have been measured and any possible extended features are noted. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1983
- Authors: Jonas, Justin Leonard
- Date: 1983 , 2013-04-15
- Subjects: Radio astronomy , Southern sky (Astronomy)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5505 , http://hdl.handle.net/10962/d1007280 , Radio astronomy , Southern sky (Astronomy)
- Description: The results of the second part of the Rhodes University Southern Sky Survey at 2.3GHz are presented. The area surveyed extends from 12hOO to 22hOO right ascension between declinations -63º and -24º. The observation technique and data reduction processes are analyzed. Digital data processing techniques used to enhance and display the data are dicussed. The results show that the Galactic emission extends as far as 40º latitude. Filamentary and loop-like structures are found superimposed on this general emission. Many of these features are unidentified as yet. A large region of emission is found to coincide with the Sco-Cen stellar association. A lower limit for the ionizing flux from the stars in the association is derived. All of the non-confused extragalactic sources with flux densities greater than O.5Jy are listed. The flux densities of these sources have been measured and any possible extended features are noted. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1983
A guide for the use of tablet PCs for teaching and learning activities for in classroom and distance learning in South African schools
- Authors: Theunissen, Kristen Emma
- Date: 2021-10-29
- Subjects: Tablet computers South Africa Makhanda , Blended learning South Africa Makhanda , Computer-assisted instruction South Africa Makhanda , Educational technology Study and teaching South Africa Makhanda , Teachers In-service training South Africa Makhanda , Pedagogical content knowledge South Africa Makhanda , Education Effect of technological innovations on South Africa Makhanda , South Africa. Department of Basic Education , TPACK (Technological Pedagogical Content Knowledge)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191920 , vital:45179
- Description: Education in South Africa is said to be in crisis in recent years as many learners cannot pass standardised tests at the correct grade level. This has encouraged the South African Government and the Department of Basic Education (DBE) to introduce technology, specifically Tablet PCs, into education to improve learning outcomes in South African government schools. Furthermore, because of the coronavirus pandemic that started in 2020, educators were increasingly expected to find alternative, digital, online methods to continue teaching learners. Thus, the need for remote or distance education suddenly became an important factor in creating a need for online, remote learning. Against this backdrop this study aimed to determine how and in what ways educators could be supported to promote effective use of Tablet PCs both in the classroom and for distance learning. This study used Action Design Research to develop a guide based on both theory and the results gathered from the educator participants at a local secondary government school in Makhanda, South Africa. The finalised guide presents recommendations to educators, principals, and the DBE to promote acceptance and adoption of technology in the classroom and for distance learning. These recommendations include the provision of data, technological training and pedagogical support, a functioning community of practice, an online learning community of practice, and support from the DBE. Other enrichment factors were also recommended. , Thesis (MCom) -- Faculty of Commerce, Information Systems, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Theunissen, Kristen Emma
- Date: 2021-10-29
- Subjects: Tablet computers South Africa Makhanda , Blended learning South Africa Makhanda , Computer-assisted instruction South Africa Makhanda , Educational technology Study and teaching South Africa Makhanda , Teachers In-service training South Africa Makhanda , Pedagogical content knowledge South Africa Makhanda , Education Effect of technological innovations on South Africa Makhanda , South Africa. Department of Basic Education , TPACK (Technological Pedagogical Content Knowledge)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191920 , vital:45179
- Description: Education in South Africa is said to be in crisis in recent years as many learners cannot pass standardised tests at the correct grade level. This has encouraged the South African Government and the Department of Basic Education (DBE) to introduce technology, specifically Tablet PCs, into education to improve learning outcomes in South African government schools. Furthermore, because of the coronavirus pandemic that started in 2020, educators were increasingly expected to find alternative, digital, online methods to continue teaching learners. Thus, the need for remote or distance education suddenly became an important factor in creating a need for online, remote learning. Against this backdrop this study aimed to determine how and in what ways educators could be supported to promote effective use of Tablet PCs both in the classroom and for distance learning. This study used Action Design Research to develop a guide based on both theory and the results gathered from the educator participants at a local secondary government school in Makhanda, South Africa. The finalised guide presents recommendations to educators, principals, and the DBE to promote acceptance and adoption of technology in the classroom and for distance learning. These recommendations include the provision of data, technological training and pedagogical support, a functioning community of practice, an online learning community of practice, and support from the DBE. Other enrichment factors were also recommended. , Thesis (MCom) -- Faculty of Commerce, Information Systems, 2021
- Full Text:
- Date Issued: 2021-10-29
Blogging, journalism and the public sphere: assessing the value of the 'blogosphere' as a new form of the public sphere : a case study of the Mail & Guardian Online's Blogmark
- Authors: Sibanda, Fortune
- Date: 2006
- Subjects: Habermas, Jürgen -- Criticism and interpretation , Mail & Guardian , Blogs -- South Africa , Online journalism -- South Africa , Electronic newspapers -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3483 , http://hdl.handle.net/10962/d1002938 , Habermas, Jürgen -- Criticism and interpretation , Mail & Guardian , Blogs -- South Africa , Online journalism -- South Africa , Electronic newspapers -- South Africa
- Description: The study seeks to investigate whether weblogs can act as virtual public spheres, where people can meet to discuss issues of interest to them. It uses the Mail & Guardian Online’s Blogmark as a case study. Weblogs – highly interactive online journals comprised of links and postings in reverse chronological order – are fast becoming an avenue of choice for many internet users wanting to share opinions and news with others online. Because of their unique read-and-write characteristics, some have equated them to the 18th century coffeehouses, around which the early forms of citizen involvement in public affairs began in early capitalist Europe. Despite their growing popularity, however, not much scholarly work has been dedicated to the practice of blogging in Africa, and particularly in South Africa. The study’s theoretical framework is drawn from Jürgen Habermas’s concept of the public sphere. While noting some of the criticisms of the Habermasian model, it is argued that the concept is instrumental in our understanding of the relationship between the media and democracy. The study, however, adopted a re-worked model of the concept of the public sphere. This model argues for the need to have a multiplicity of public sphericules (instead of one single public sphere as advocated by Habermas), around which individuals can congregate to discuss issues of common concern to them. Using a combination of qualitative content analysis, self-completion questionnaires and a semi-structured interview, the study found Blogmark to be an example of how emerging internet genres such as weblogs can be vehicles of citizen involvement in public life. A range of issues were discussed in the blog, from politics, race and ii i gender issues, to personal anecdotes, relationships, and sex. However, while some posts exhibited high levels of interactivity, with many bloggers joining in to offer their opinions, some read like online monologues. The study argues that although blogging is a practice that is still limited to a few privileged individuals, with the everrising size of the ‘blogosphere’, weblogs such as Blogmark are making a small but not insignificant contribution to the number of voices that can be heard in the public realm.
- Full Text:
- Date Issued: 2006
- Authors: Sibanda, Fortune
- Date: 2006
- Subjects: Habermas, Jürgen -- Criticism and interpretation , Mail & Guardian , Blogs -- South Africa , Online journalism -- South Africa , Electronic newspapers -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3483 , http://hdl.handle.net/10962/d1002938 , Habermas, Jürgen -- Criticism and interpretation , Mail & Guardian , Blogs -- South Africa , Online journalism -- South Africa , Electronic newspapers -- South Africa
- Description: The study seeks to investigate whether weblogs can act as virtual public spheres, where people can meet to discuss issues of interest to them. It uses the Mail & Guardian Online’s Blogmark as a case study. Weblogs – highly interactive online journals comprised of links and postings in reverse chronological order – are fast becoming an avenue of choice for many internet users wanting to share opinions and news with others online. Because of their unique read-and-write characteristics, some have equated them to the 18th century coffeehouses, around which the early forms of citizen involvement in public affairs began in early capitalist Europe. Despite their growing popularity, however, not much scholarly work has been dedicated to the practice of blogging in Africa, and particularly in South Africa. The study’s theoretical framework is drawn from Jürgen Habermas’s concept of the public sphere. While noting some of the criticisms of the Habermasian model, it is argued that the concept is instrumental in our understanding of the relationship between the media and democracy. The study, however, adopted a re-worked model of the concept of the public sphere. This model argues for the need to have a multiplicity of public sphericules (instead of one single public sphere as advocated by Habermas), around which individuals can congregate to discuss issues of common concern to them. Using a combination of qualitative content analysis, self-completion questionnaires and a semi-structured interview, the study found Blogmark to be an example of how emerging internet genres such as weblogs can be vehicles of citizen involvement in public life. A range of issues were discussed in the blog, from politics, race and ii i gender issues, to personal anecdotes, relationships, and sex. However, while some posts exhibited high levels of interactivity, with many bloggers joining in to offer their opinions, some read like online monologues. The study argues that although blogging is a practice that is still limited to a few privileged individuals, with the everrising size of the ‘blogosphere’, weblogs such as Blogmark are making a small but not insignificant contribution to the number of voices that can be heard in the public realm.
- Full Text:
- Date Issued: 2006
A holy people: a study in the ecclesiology of Andrew Murray
- Neethling, Johann Christiaan
- Authors: Neethling, Johann Christiaan
- Date: 1975
- Subjects: Murray, Andrew, 1828-1917 , Nederduitse Gereformeerde Kerk , Nederduitsch Hervormde Kerk van Afrika -- History , Nederduitse Gereformeerde Gemeente Worcester , Nederduitse Gereformeerde Gemeente Bloemfontein , Nederduitse Gereformeerde Gemeente Wellington , Theology, Doctrinal -- South Africa -- History , Church history
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1287 , http://hdl.handle.net/10962/d1013592
- Description: The thesis seeks to show Andrew Murray's growing understanding of what it meant to be the elect of God in contrast to other prevailing notions. In his confrontation with the Trekker communities, the majority of whom were rigid Calvinists, stressing a divine election based on the notions of biological and cultural identity, Murray found little of the holy behaviour which ought to characterize the people of God. The elect should be seen to be the elect by their fruits. Instead there was divisiveness, discrimination, party spirit and other forms of ungodliness. Faced with the immensity of the task in identifying the true Church and building God's people up in holiness, Murray began to sense the necessity of another 'dimension' within the Church's regular means of grace of preaching, the sacraments, and discipline. The revival of 1860, focussed Murray's attention in a new and vital way on the work of the Holy Spirit in breathing new life into the Church and in empowering believers to live lives pleasing to God. The 'indiscriminate' effects of the Holy Spirit's work convinced Murray that the Gospel and thus the Church was not the possession of the white colonist, Dutch or English, but that the black and brown man had an equal claim on the Gospel and as much right to become a member of Christ's Church. Murray's understanding of the Christian life as continual abiding in Christ by the power of the indwelling Holy Spirit meant that the believer came to have the mind of Christ and to partake of His holiness. This holiness evidenced itself in the believer having Christ's concern for the lost. Mission, therefore, became this supreme end of the Church. The struggle with the forces of liberalism raised the new issue that unbelievers could no longer be simply 'heathen blacks' or English but most of all Dutch. The support of the civil courts of those disciplined by the Church brought the whole problem of ecclesiology to the fore and led Murray to the conclusion of the necessary separation of the Church from the State. Murray's discovery that in various ages, nations and Church traditions there were those with the same passionate desire for God' s holiness, led him into an increasing awareness of the catholicity of the Church. True holiness demanded the love and unity of all God's children. Murray's ecclesiology was a biblically-based one at a time when communities were beginning to be formed by other than biblical notions and principles and by a people who were trying to pack more into the notion of a people of God than Scripture gave warrant for. The emphasis for which Murray stood made for an ecclesiology that simply could not be confined.
- Full Text:
- Date Issued: 1975
- Authors: Neethling, Johann Christiaan
- Date: 1975
- Subjects: Murray, Andrew, 1828-1917 , Nederduitse Gereformeerde Kerk , Nederduitsch Hervormde Kerk van Afrika -- History , Nederduitse Gereformeerde Gemeente Worcester , Nederduitse Gereformeerde Gemeente Bloemfontein , Nederduitse Gereformeerde Gemeente Wellington , Theology, Doctrinal -- South Africa -- History , Church history
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1287 , http://hdl.handle.net/10962/d1013592
- Description: The thesis seeks to show Andrew Murray's growing understanding of what it meant to be the elect of God in contrast to other prevailing notions. In his confrontation with the Trekker communities, the majority of whom were rigid Calvinists, stressing a divine election based on the notions of biological and cultural identity, Murray found little of the holy behaviour which ought to characterize the people of God. The elect should be seen to be the elect by their fruits. Instead there was divisiveness, discrimination, party spirit and other forms of ungodliness. Faced with the immensity of the task in identifying the true Church and building God's people up in holiness, Murray began to sense the necessity of another 'dimension' within the Church's regular means of grace of preaching, the sacraments, and discipline. The revival of 1860, focussed Murray's attention in a new and vital way on the work of the Holy Spirit in breathing new life into the Church and in empowering believers to live lives pleasing to God. The 'indiscriminate' effects of the Holy Spirit's work convinced Murray that the Gospel and thus the Church was not the possession of the white colonist, Dutch or English, but that the black and brown man had an equal claim on the Gospel and as much right to become a member of Christ's Church. Murray's understanding of the Christian life as continual abiding in Christ by the power of the indwelling Holy Spirit meant that the believer came to have the mind of Christ and to partake of His holiness. This holiness evidenced itself in the believer having Christ's concern for the lost. Mission, therefore, became this supreme end of the Church. The struggle with the forces of liberalism raised the new issue that unbelievers could no longer be simply 'heathen blacks' or English but most of all Dutch. The support of the civil courts of those disciplined by the Church brought the whole problem of ecclesiology to the fore and led Murray to the conclusion of the necessary separation of the Church from the State. Murray's discovery that in various ages, nations and Church traditions there were those with the same passionate desire for God' s holiness, led him into an increasing awareness of the catholicity of the Church. True holiness demanded the love and unity of all God's children. Murray's ecclesiology was a biblically-based one at a time when communities were beginning to be formed by other than biblical notions and principles and by a people who were trying to pack more into the notion of a people of God than Scripture gave warrant for. The emphasis for which Murray stood made for an ecclesiology that simply could not be confined.
- Full Text:
- Date Issued: 1975
The geology, petrology and geochemistry of the mineralization and hydrothermal alteration at Ongeama, Ongombo and Matchless West Extension, Namibia
- Authors: Moroni, Marilena
- Date: 1991
- Subjects: Geology -- Namibia , Petrology -- Namibia , Geochemistry -- Namibia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5045 , http://hdl.handle.net/10962/d1007693 , Geology -- Namibia , Petrology -- Namibia , Geochemistry -- Namibia
- Description: The Matchless Amphibolite Belt (Damara Orogen, Namibia) hosts several volcanogenic-exhalative, sediment-hosted stratiform cupriferous pyrite deposits. These are thought to be related to submarine volcanism during the early evolutionary stages of a narrow Damaran ocean, the Matchless Trough. The mineralized bodies examined (Ongeama, Ongombo and Matchless West Extension) are deformed and metamorphosed to low-medium grade (greenschist-amphibolite facies). They are associated with metapelite and amphibolite country rocks, and crop out as prominent limonite-rich gossans. The elongated shape of the sulphide bodies suggests a structural control. The mineralization normally consists of a variably developed massive sulphide portion, either quartz-, talc- or amphibole-bearing, and a stratigraphically overlying, extensive horizon of sulphide- and baryte-bearing exhalite (magnetite quartzite and less common talc- and actinolite-bearing schists). Lateral and vertical mineralogical changes within the mineralization match with significant variations in the element distribution. A metamorphosed and deformed alteration pipe, indicating the position of the fluid conduit, can be recognized in association with some ore bodies. The formation of quartz-muscovite and chlorite alteration envelopes (Ongeama, Matchless West Extension) and the presence of subtle mineralogical changes (Ongombo) in the immediate wallrocks, accompanied by extensive redistribution, leaching and introduction of elements from outside, suggest the hydrothermal metasomatic origin of the alteration zones. Element zoning within the mineralized bodies can be related to the original position of the vent, possibly coinciding with the intersection of the axis of the alteration pipe with the sulphide body. Cu, Zn, Au (pro parte) and Mo are enriched proximal to the vent, whereas Pb, Ba, Mn, Ag, Au, Sn, Bi and W enrichment characterizes the distal facies of the mineralization. In spite of the obliterating and disrupting effects of the regional dynamo-metamorphism, the element distribution within the mineralization and alteration zones examined is comparable with the geochemical trends observed in present-day mineralizing systems in early- stage oceanic environments (e.g. Guaymas Basin). During exploration for blind volcanogenic mineralization, the detection of hydrothermally altered rocks is fundamental in indicating the proximity to the mineralization. The localization of the alteration zone is also important in the interpretation of the regional geology of the explored area: in deformed terrains the assessment of the stratigraphic position of the alteration zone, relative to the mineralization, helps in establishing the polarity of the sequence.
- Full Text:
- Date Issued: 1991
- Authors: Moroni, Marilena
- Date: 1991
- Subjects: Geology -- Namibia , Petrology -- Namibia , Geochemistry -- Namibia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5045 , http://hdl.handle.net/10962/d1007693 , Geology -- Namibia , Petrology -- Namibia , Geochemistry -- Namibia
- Description: The Matchless Amphibolite Belt (Damara Orogen, Namibia) hosts several volcanogenic-exhalative, sediment-hosted stratiform cupriferous pyrite deposits. These are thought to be related to submarine volcanism during the early evolutionary stages of a narrow Damaran ocean, the Matchless Trough. The mineralized bodies examined (Ongeama, Ongombo and Matchless West Extension) are deformed and metamorphosed to low-medium grade (greenschist-amphibolite facies). They are associated with metapelite and amphibolite country rocks, and crop out as prominent limonite-rich gossans. The elongated shape of the sulphide bodies suggests a structural control. The mineralization normally consists of a variably developed massive sulphide portion, either quartz-, talc- or amphibole-bearing, and a stratigraphically overlying, extensive horizon of sulphide- and baryte-bearing exhalite (magnetite quartzite and less common talc- and actinolite-bearing schists). Lateral and vertical mineralogical changes within the mineralization match with significant variations in the element distribution. A metamorphosed and deformed alteration pipe, indicating the position of the fluid conduit, can be recognized in association with some ore bodies. The formation of quartz-muscovite and chlorite alteration envelopes (Ongeama, Matchless West Extension) and the presence of subtle mineralogical changes (Ongombo) in the immediate wallrocks, accompanied by extensive redistribution, leaching and introduction of elements from outside, suggest the hydrothermal metasomatic origin of the alteration zones. Element zoning within the mineralized bodies can be related to the original position of the vent, possibly coinciding with the intersection of the axis of the alteration pipe with the sulphide body. Cu, Zn, Au (pro parte) and Mo are enriched proximal to the vent, whereas Pb, Ba, Mn, Ag, Au, Sn, Bi and W enrichment characterizes the distal facies of the mineralization. In spite of the obliterating and disrupting effects of the regional dynamo-metamorphism, the element distribution within the mineralization and alteration zones examined is comparable with the geochemical trends observed in present-day mineralizing systems in early- stage oceanic environments (e.g. Guaymas Basin). During exploration for blind volcanogenic mineralization, the detection of hydrothermally altered rocks is fundamental in indicating the proximity to the mineralization. The localization of the alteration zone is also important in the interpretation of the regional geology of the explored area: in deformed terrains the assessment of the stratigraphic position of the alteration zone, relative to the mineralization, helps in establishing the polarity of the sequence.
- Full Text:
- Date Issued: 1991
A decade of changes Eastern Cape white commercial farmers' discourses of democracy
- Authors: Böhmke, Werner
- Date: 2005
- Subjects: Farmers -- Psychology , Agriculture -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Democracy -- South Africa -- Eastern Cape , Political culture -- South Africa -- Eastern Cape , Social psychology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2934 , http://hdl.handle.net/10962/d1002443 , Farmers -- Psychology , Agriculture -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Democracy -- South Africa -- Eastern Cape , Political culture -- South Africa -- Eastern Cape , Social psychology -- South Africa -- Eastern Cape
- Description: This paper deals with an analysis of the discursive accounts of Eastern Cape white commercial farmers on the subject of Democracy. Drawing on the theoretical perspectives of Social Constructionism and Discourse Analysis – which view individuals’ accounts of their realities as produced and informed by their particular social and historical context – the paper seeks to provide an analysis of the content of, and rhetorical strategies within the participants’ accounts and explanations. Such accounts of the social, historical and political circumstances in which Eastern Cape commercial farmers find themselves are thought to provide valuable insights into the manner in which the process of democratisation has been received by members of the agricultural sector. Data collection was conducted via brief, audio taped, semi-structured interviews. The participants were all white men and women, living in a commercial farming region of the Eastern Cape Province. Responses to the interviews were subjected to the Discourse Analytical procedure advanced by Ian Parker. Analyses reveal that participants are critical of the notion of democracy; utilize specific rhetorical and argumentation strategies; make use of notions and techniques of ‘Othering’; and subscribe to a colonial / patriarchal ideology which attempts to idealize pre-democratic South Africa. These findings illustrate what is in many ways still an ongoing political and ideological struggle in the rural regions of the country.
- Full Text:
- Date Issued: 2005
- Authors: Böhmke, Werner
- Date: 2005
- Subjects: Farmers -- Psychology , Agriculture -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Democracy -- South Africa -- Eastern Cape , Political culture -- South Africa -- Eastern Cape , Social psychology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2934 , http://hdl.handle.net/10962/d1002443 , Farmers -- Psychology , Agriculture -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Democracy -- South Africa -- Eastern Cape , Political culture -- South Africa -- Eastern Cape , Social psychology -- South Africa -- Eastern Cape
- Description: This paper deals with an analysis of the discursive accounts of Eastern Cape white commercial farmers on the subject of Democracy. Drawing on the theoretical perspectives of Social Constructionism and Discourse Analysis – which view individuals’ accounts of their realities as produced and informed by their particular social and historical context – the paper seeks to provide an analysis of the content of, and rhetorical strategies within the participants’ accounts and explanations. Such accounts of the social, historical and political circumstances in which Eastern Cape commercial farmers find themselves are thought to provide valuable insights into the manner in which the process of democratisation has been received by members of the agricultural sector. Data collection was conducted via brief, audio taped, semi-structured interviews. The participants were all white men and women, living in a commercial farming region of the Eastern Cape Province. Responses to the interviews were subjected to the Discourse Analytical procedure advanced by Ian Parker. Analyses reveal that participants are critical of the notion of democracy; utilize specific rhetorical and argumentation strategies; make use of notions and techniques of ‘Othering’; and subscribe to a colonial / patriarchal ideology which attempts to idealize pre-democratic South Africa. These findings illustrate what is in many ways still an ongoing political and ideological struggle in the rural regions of the country.
- Full Text:
- Date Issued: 2005
Rhodeo, Vol. 9, No. 2
- Date: 1946-05-26
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14424 , http://hdl.handle.net/10962/d1019296
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1946-05-26
- Date: 1946-05-26
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14424 , http://hdl.handle.net/10962/d1019296
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1946-05-26