Synthesis, characterization and photodynamic therapy properties of an octa-4-tert-butylphenoxy-substituted phosphorus (V) triazatetrabenzcorrole
- Shi, Maohu, Tian, Jiangwei, Mkhize, Colin, Kubheka, Gugu, Zhou, Jinfeng, Mack, John, Nyokong, Tebello, Shen, Zhen
- Authors: Shi, Maohu , Tian, Jiangwei , Mkhize, Colin , Kubheka, Gugu , Zhou, Jinfeng , Mack, John , Nyokong, Tebello , Shen, Zhen
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241494 , vital:50944 , xlink:href="https://doi.org/10.1142/S1088424614500436"
- Description: A novel octa-4-tert-butylphenoxy-substituted phosphorus(V) triazatetrabenzcorrole (PVTBC), has been synthesized and characterized by MALDI-TOF MS and NMR, FT-IR and MCD spectroscopy. The fluorescence emission spectrum was used to determine the fluorescence quantum yield and the quantum yield for singlet oxygen generation was calculated by using 1,3-diphenylisobenzofuran as a scavenger. The photocytoxicity against U87MG cells was measured. The results indicated that PVTBC is potentially useful as an NIR region photosensitizer for photodynamic therapy (PDT).
- Full Text:
- Date Issued: 2014
- Authors: Shi, Maohu , Tian, Jiangwei , Mkhize, Colin , Kubheka, Gugu , Zhou, Jinfeng , Mack, John , Nyokong, Tebello , Shen, Zhen
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241494 , vital:50944 , xlink:href="https://doi.org/10.1142/S1088424614500436"
- Description: A novel octa-4-tert-butylphenoxy-substituted phosphorus(V) triazatetrabenzcorrole (PVTBC), has been synthesized and characterized by MALDI-TOF MS and NMR, FT-IR and MCD spectroscopy. The fluorescence emission spectrum was used to determine the fluorescence quantum yield and the quantum yield for singlet oxygen generation was calculated by using 1,3-diphenylisobenzofuran as a scavenger. The photocytoxicity against U87MG cells was measured. The results indicated that PVTBC is potentially useful as an NIR region photosensitizer for photodynamic therapy (PDT).
- Full Text:
- Date Issued: 2014
Synthesis, characterization, and biological studies of pyrazolone Schiff bases and their transition metal complexes
- Authors: Idemudia, Omoruyi Gold
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11340 , http://hdl.handle.net/10353/d1016068
- Description: Some new acylpyrazolone Schiff bases have been synthesized from the condensation reaction of two acylpyrazolone diketone precursors with phenylhydrazine, 2,4-dinitrophenylhydrazine and sulfanilamide. They have been fully characterized by elemental analysis and spectroscopic techniques (IR,1H and 13C NMR, and mass-spectra). The single crystal structure of the benzoyl derivative acylpyrazolone Schiff bases have been obtained and analyzed by X-ray crystallography technique. Solid state X-ray diffraction revealed a keto tautomer Schiff base in solid state. Mn(II), Co(II), Ni(II) and Cu(II) complexes with the Schiff bases have been synthesized and characterized by elemental analysis, IR and UV-VIS spectroscopy, magnetic susceptibility measurements, and thermal studies (TGA and DTG). An octahedral geometry around the transition metal ion, consisting of two bidentate Schiff base ligands bonding through the azometine nitrogen and ketonic oxygen have been proposed based on careful interpretation of available analytical and spectroscopic characterization results. Two water molecules as ligands complete the octahedral geometry in all cases. Using the invitro disc diffusion method for screening synthesized compounds against selected gram positive and gram negative bacterial at 40 mg/mL, and the DPPH free radical scavenging methods at 0.50, 0.25 and 0.13 mg/mL, the synthesized Schiff base and metal complexes showed varying biological activities. 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one sul29 fanilamide showed more activity generally, exhibiting a broad spectrum activity against all selected bacterial in some cases. Mn(II), Co(II) and Ni(II) complexes of sulfanilamide Schiff base with the acetylpyrazolone derivative 4-acetyl-3-methyl-1-phenyl-2-pyrazolin-5-one sulfanilamide, exhibited a stronger and very good DPPH radical scavenging activity as good as ascorbic acid on comparing, but not with Cu(II). As such they could be important antitumour candidates.
- Full Text:
- Date Issued: 2014
- Authors: Idemudia, Omoruyi Gold
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11340 , http://hdl.handle.net/10353/d1016068
- Description: Some new acylpyrazolone Schiff bases have been synthesized from the condensation reaction of two acylpyrazolone diketone precursors with phenylhydrazine, 2,4-dinitrophenylhydrazine and sulfanilamide. They have been fully characterized by elemental analysis and spectroscopic techniques (IR,1H and 13C NMR, and mass-spectra). The single crystal structure of the benzoyl derivative acylpyrazolone Schiff bases have been obtained and analyzed by X-ray crystallography technique. Solid state X-ray diffraction revealed a keto tautomer Schiff base in solid state. Mn(II), Co(II), Ni(II) and Cu(II) complexes with the Schiff bases have been synthesized and characterized by elemental analysis, IR and UV-VIS spectroscopy, magnetic susceptibility measurements, and thermal studies (TGA and DTG). An octahedral geometry around the transition metal ion, consisting of two bidentate Schiff base ligands bonding through the azometine nitrogen and ketonic oxygen have been proposed based on careful interpretation of available analytical and spectroscopic characterization results. Two water molecules as ligands complete the octahedral geometry in all cases. Using the invitro disc diffusion method for screening synthesized compounds against selected gram positive and gram negative bacterial at 40 mg/mL, and the DPPH free radical scavenging methods at 0.50, 0.25 and 0.13 mg/mL, the synthesized Schiff base and metal complexes showed varying biological activities. 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one sul29 fanilamide showed more activity generally, exhibiting a broad spectrum activity against all selected bacterial in some cases. Mn(II), Co(II) and Ni(II) complexes of sulfanilamide Schiff base with the acetylpyrazolone derivative 4-acetyl-3-methyl-1-phenyl-2-pyrazolin-5-one sulfanilamide, exhibited a stronger and very good DPPH radical scavenging activity as good as ascorbic acid on comparing, but not with Cu(II). As such they could be important antitumour candidates.
- Full Text:
- Date Issued: 2014
Synthesis, photophysicochemical properties and TD-DFT calculations of tetrakis (2-benzoyl-4-chlorophenoxy) phthalocyanines
- Yilmaz, Yusuf, Mack, John, Sener, M Kasim, Sönmez, Mehmet, Nyokong, Tebello
- Authors: Yilmaz, Yusuf , Mack, John , Sener, M Kasim , Sönmez, Mehmet , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241538 , vital:50948 , xlink:href="https://doi.org/10.1142/S1088424614500047"
- Description: The synthesis of metal free, magnesium and zinc tetrakis(2-benzoyl-4-chlorophenoxy) phthalocyanine derivatives (2–4) is described along with their characterization by elemental analysis, IR, UV-visible absorption, and 1H NMR spectroscopy and mass spectrometry. Trends observed in the fluorescence, triplet state, singlet oxygen and photodegradation quantum yields and the triplet state lifetimes are also analyzed. The compounds exhibit high solubility in a wide range of organic solvents and no evidence of aggregation was observed over a wide concentration range. The Zn(II) complex (4) was found to have a very high singlet oxygen quantum yield (ΦΔ = 0.78) in dimethylsulfoxide (DMSO) and a reasonably large triplet state quantum yield (ΦT = 0.82). The photophysical and photochemical properties clearly demonstrate that these compounds could prove useful in singlet oxygen applications such as photodynamic therapy (PDT). DFT and TD-DFT calculations were used to assess the impact of the positional isomerism of the 2-benzoyl-4-chlorophenoxy substituents on the electronic structures and optical spectroscopy.
- Full Text:
- Date Issued: 2014
- Authors: Yilmaz, Yusuf , Mack, John , Sener, M Kasim , Sönmez, Mehmet , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241538 , vital:50948 , xlink:href="https://doi.org/10.1142/S1088424614500047"
- Description: The synthesis of metal free, magnesium and zinc tetrakis(2-benzoyl-4-chlorophenoxy) phthalocyanine derivatives (2–4) is described along with their characterization by elemental analysis, IR, UV-visible absorption, and 1H NMR spectroscopy and mass spectrometry. Trends observed in the fluorescence, triplet state, singlet oxygen and photodegradation quantum yields and the triplet state lifetimes are also analyzed. The compounds exhibit high solubility in a wide range of organic solvents and no evidence of aggregation was observed over a wide concentration range. The Zn(II) complex (4) was found to have a very high singlet oxygen quantum yield (ΦΔ = 0.78) in dimethylsulfoxide (DMSO) and a reasonably large triplet state quantum yield (ΦT = 0.82). The photophysical and photochemical properties clearly demonstrate that these compounds could prove useful in singlet oxygen applications such as photodynamic therapy (PDT). DFT and TD-DFT calculations were used to assess the impact of the positional isomerism of the 2-benzoyl-4-chlorophenoxy substituents on the electronic structures and optical spectroscopy.
- Full Text:
- Date Issued: 2014
Synthetic analogues of marine bisindole alkaloids as potent selective inhibitors of MRSA pyruvate kinase
- Veale, Clinton Gareth Lancaster
- Authors: Veale, Clinton Gareth Lancaster
- Date: 2014 , 2014-04-02
- Subjects: Alkaloids , Pyruvate kinase , Staphylococcus aureus , Antibiotics , Sponges -- South Africa , Imidazoles , Biological assay , Antibacterial agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4563 , http://hdl.handle.net/10962/d1020893
- Description: Globally, methicillin resistant Staphylococcus aureus (MRSA) has become increasingly difficult to manage in the clinic and new antibiotics are required. The structure activity relationship (SAR) study presented in this thesis forms part of an international collaborative effort to identify potent and selective inhibitors of an MRSA pyruvate kinase (PK) enzyme target. In earlier work the known marine natural product bromodeoxytopsentin (1.6), isolated from a South African marine sponge Topsentia pachastrelloides, exhibited selective and significant inhibition of MRSA PK (IC₅₀ 60 nM). Accordingly bromodeoxytopsentin provided the initial chemical scaffold around which our SAR study was developed. Following a comprehensive introduction, providing the necessary background to the research described in subsequent Chapters, this thesis has been divided into three major parts. Part one (Chapter 2) documents the synthesis of two natural imidazole containing topsentin analogues 1.40, 1.46, five new synthetic analogues 1.58—1.61, 2.104. In the process we developed a new method for the synthesis of topsentin derivatives via selenium dioxide mediated oxidation of N-Boc protected 3-acetylindoles to yield glyoxal intermediates which were subsequently cyclized and deprotected to yield the desired products. Interestingly we were able to demonstrate a delicate relationship between the relative equivalents of selenium dioxide and water used during the oxidation step, careful manipulation of which was required to prevent the uncontrolled formation of side products. Synthetic compounds 1.40, 1.46, 1.58—1.61 were found to be potent inhibitors of MRSA PK (IC₅₀ 238, 2.1, 23, 1.4, 6.3 and 3.2 nM respectively) with 1000-10000 fold selectivity for MRSA PK over four human orthologs. In the second part of this thesis (Chapter 3) we report the successful synthesis of a cohort of previously unknown thiazole containing bisindole topsentin analogues 1.62—1.68 via a Hantzsch thiazole synthesis. Bioassay results revealed that these compounds were only moderate inhibitors of MRSA PK (IC₅₀ 5.1—20 μM) which suggested that inhibitory activity was significantly reduced upon substitution of the central imidazole ring of topsentin type analogues with a thiazole type ring. In addition in Chapter 3 we describe unsuccessful attempts to regiospecifically synthesize oxazole and imidazole topsentin analogues through a similar Hantzsch method. As a consequence of our efforts in this regard we investigated three key reactions in depth, namely the synthesis of 2.2, 3.38, 3.40, 3.41 via α-bromination of 3-acetylindole and the synthesis of indolyl-3-carbonylnitriles 2.13, 3.45—3.47 and α-oxo-1H-indole-3-thioacetamides 3.48—3.51. The investigation of the latter led to the isolation and elucidation of two anomalous N,N-dimethyl-1H-indole-3-carboxamides 3.52 and 3.53. Finally the third part of this thesis (Chapter 4) deals with in silico assessment of the binding of both the imidazole and thiazole containing bisindole alkaloids to the MRSA PK protein which initially guided our SAR studies. In this chapter we reveal that there appears to be no correlation between in silico binding predictions and in vitro MRSA PK inhibitory bioassay data. Superficially it seems that binding energy as determined by the docking program used for these studies correlated with the size of the indole substituents and did not reflect IC₅₀ MRSA PK inhibitory data. Although this led us to computationally explore possible alternative binding sites no clear alternative has been identified.
- Full Text:
- Date Issued: 2014
- Authors: Veale, Clinton Gareth Lancaster
- Date: 2014 , 2014-04-02
- Subjects: Alkaloids , Pyruvate kinase , Staphylococcus aureus , Antibiotics , Sponges -- South Africa , Imidazoles , Biological assay , Antibacterial agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4563 , http://hdl.handle.net/10962/d1020893
- Description: Globally, methicillin resistant Staphylococcus aureus (MRSA) has become increasingly difficult to manage in the clinic and new antibiotics are required. The structure activity relationship (SAR) study presented in this thesis forms part of an international collaborative effort to identify potent and selective inhibitors of an MRSA pyruvate kinase (PK) enzyme target. In earlier work the known marine natural product bromodeoxytopsentin (1.6), isolated from a South African marine sponge Topsentia pachastrelloides, exhibited selective and significant inhibition of MRSA PK (IC₅₀ 60 nM). Accordingly bromodeoxytopsentin provided the initial chemical scaffold around which our SAR study was developed. Following a comprehensive introduction, providing the necessary background to the research described in subsequent Chapters, this thesis has been divided into three major parts. Part one (Chapter 2) documents the synthesis of two natural imidazole containing topsentin analogues 1.40, 1.46, five new synthetic analogues 1.58—1.61, 2.104. In the process we developed a new method for the synthesis of topsentin derivatives via selenium dioxide mediated oxidation of N-Boc protected 3-acetylindoles to yield glyoxal intermediates which were subsequently cyclized and deprotected to yield the desired products. Interestingly we were able to demonstrate a delicate relationship between the relative equivalents of selenium dioxide and water used during the oxidation step, careful manipulation of which was required to prevent the uncontrolled formation of side products. Synthetic compounds 1.40, 1.46, 1.58—1.61 were found to be potent inhibitors of MRSA PK (IC₅₀ 238, 2.1, 23, 1.4, 6.3 and 3.2 nM respectively) with 1000-10000 fold selectivity for MRSA PK over four human orthologs. In the second part of this thesis (Chapter 3) we report the successful synthesis of a cohort of previously unknown thiazole containing bisindole topsentin analogues 1.62—1.68 via a Hantzsch thiazole synthesis. Bioassay results revealed that these compounds were only moderate inhibitors of MRSA PK (IC₅₀ 5.1—20 μM) which suggested that inhibitory activity was significantly reduced upon substitution of the central imidazole ring of topsentin type analogues with a thiazole type ring. In addition in Chapter 3 we describe unsuccessful attempts to regiospecifically synthesize oxazole and imidazole topsentin analogues through a similar Hantzsch method. As a consequence of our efforts in this regard we investigated three key reactions in depth, namely the synthesis of 2.2, 3.38, 3.40, 3.41 via α-bromination of 3-acetylindole and the synthesis of indolyl-3-carbonylnitriles 2.13, 3.45—3.47 and α-oxo-1H-indole-3-thioacetamides 3.48—3.51. The investigation of the latter led to the isolation and elucidation of two anomalous N,N-dimethyl-1H-indole-3-carboxamides 3.52 and 3.53. Finally the third part of this thesis (Chapter 4) deals with in silico assessment of the binding of both the imidazole and thiazole containing bisindole alkaloids to the MRSA PK protein which initially guided our SAR studies. In this chapter we reveal that there appears to be no correlation between in silico binding predictions and in vitro MRSA PK inhibitory bioassay data. Superficially it seems that binding energy as determined by the docking program used for these studies correlated with the size of the indole substituents and did not reflect IC₅₀ MRSA PK inhibitory data. Although this led us to computationally explore possible alternative binding sites no clear alternative has been identified.
- Full Text:
- Date Issued: 2014
Talent management as a strategy to promote succession of junior managers at Edgars
- Authors: Walters, Charles
- Date: 2014
- Subjects: Organizational effectiveness , Occupation , Career development , Success in business
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/47837 , vital:40385
- Description: Talent Management has become one of the biggest challenges facing businesses today. With the skill shortage and the influx of clothing retailers into South Africa in the past two years, the war on talent has intensified. With this in mind the objective of the study was to investigate if Edgars had a successful talent management strategy to promote junior managers through succession. Talent management has different parts including recruitment, learning and development, performance management, reward, leadership, employee value proposition, retention and succession. This study unpacks the literature on talent management and its components and takes a deeper look at the strategy adopted by Edgars. The study highlights the importance of talent management and that there should be clear strategies for every part that makes up the talent management framework. Empirical studies are done on the different sub sections of talent management, findings and recommendations are reported in the final chapters. The target population for this study consisted of junior managers at Edgars, where the majority of key value roles critical for development and store manager succession are. A sample of forty respondents was randomly selected from the total junior management population at Edgars. The findings suggested that when an organisation has effective talent management strategy, it is more likely to create a compelling employee value proposition that is conducive to sustain succession of great talent. Furthermore, the findings revealed that Edgars is effective in applying certain talent strategies while other areas required more attention and focus.
- Full Text:
- Date Issued: 2014
- Authors: Walters, Charles
- Date: 2014
- Subjects: Organizational effectiveness , Occupation , Career development , Success in business
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/47837 , vital:40385
- Description: Talent Management has become one of the biggest challenges facing businesses today. With the skill shortage and the influx of clothing retailers into South Africa in the past two years, the war on talent has intensified. With this in mind the objective of the study was to investigate if Edgars had a successful talent management strategy to promote junior managers through succession. Talent management has different parts including recruitment, learning and development, performance management, reward, leadership, employee value proposition, retention and succession. This study unpacks the literature on talent management and its components and takes a deeper look at the strategy adopted by Edgars. The study highlights the importance of talent management and that there should be clear strategies for every part that makes up the talent management framework. Empirical studies are done on the different sub sections of talent management, findings and recommendations are reported in the final chapters. The target population for this study consisted of junior managers at Edgars, where the majority of key value roles critical for development and store manager succession are. A sample of forty respondents was randomly selected from the total junior management population at Edgars. The findings suggested that when an organisation has effective talent management strategy, it is more likely to create a compelling employee value proposition that is conducive to sustain succession of great talent. Furthermore, the findings revealed that Edgars is effective in applying certain talent strategies while other areas required more attention and focus.
- Full Text:
- Date Issued: 2014
Tapping into the World of Terpenoids
- Authors: Oyedeji, A O
- Date: 2014
- Subjects: Terpenoids , Terpenes , Medicinal plants -- Analysis
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1111 , vital:30607
- Description: Terpenes are a class of secondary metabolites found in plants and insects (such as termites or swallowtail butterflies). Terpenes are strong-smelling aromatic hydrocarbon which are used by plants/ insects to protect themselves by deterring parasites. They are secondary metabolites synthesized in plants. When a hydrogen or atoms of hydrogen, are replaced by other atoms such as oxygen, in a terpene compound, the terpene becomes a terpenoid (also known as isoprenoids). Terpenoids are a large and diverse class of naturally occurring organic chemicals, derived from five-carbon isoprene units assembled and modified in thousands of ways. They are multicyclic structures that differ from one another not only in functional group but also in their basic carbon skeletons. Terpenoids are found in all classes of living things, and are the largest group of natural products.
- Full Text:
- Date Issued: 2014
- Authors: Oyedeji, A O
- Date: 2014
- Subjects: Terpenoids , Terpenes , Medicinal plants -- Analysis
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1111 , vital:30607
- Description: Terpenes are a class of secondary metabolites found in plants and insects (such as termites or swallowtail butterflies). Terpenes are strong-smelling aromatic hydrocarbon which are used by plants/ insects to protect themselves by deterring parasites. They are secondary metabolites synthesized in plants. When a hydrogen or atoms of hydrogen, are replaced by other atoms such as oxygen, in a terpene compound, the terpene becomes a terpenoid (also known as isoprenoids). Terpenoids are a large and diverse class of naturally occurring organic chemicals, derived from five-carbon isoprene units assembled and modified in thousands of ways. They are multicyclic structures that differ from one another not only in functional group but also in their basic carbon skeletons. Terpenoids are found in all classes of living things, and are the largest group of natural products.
- Full Text:
- Date Issued: 2014
Targeting and characterizing potentially high yield aquifers in the neotectonic zones in the Eastern Cape Province in South Africa
- Authors: Madi, Kakaba
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: vital:11530 , http://hdl.handle.net/10353/d1021270
- Description: The Eastern Cape Province has, besides the three known neotectonic belts (southern, eastern and northern) a fourth zone, which is inactive. This inactive zone is located almost in its central part north of the southern neotectonic zone, and south of the northern neotectonic belt. The three above mentioned neotectonic belts (southern, eastern and northern) were chosen for this study, each one with its own characteristics. This study aims at characterizing and targeting potentially high yield aquifers in the neotectonic zones in the Eastern Cape Province. The methods used in this study include: 1) A comprehensive literature review on neotectonics in South Africa in general and in the Eastern Cape Province in particular; 2) Extraction of lineaments through remote sensing and examination of digital elevation models; 3) Examination of seismic data for the subsurface visualization onshore and offshore; 4) Study on the genesis of the Grahamstown kaolin deposits through the structural component; and 5) Acquisition and interpretation of magnetic, electromagnetic and radiometric data from three of the hot springs in the northern neotectonic belt. The results indicate the following: 1) Old map of seismic epicentres in South Africa need to be reviewed continually. The Eastern Cape was regarded as quiescent in terms of seismicity. However, the investigation from recent seismic epicenters downloadable from the IRIS website has shown that recent seismic events occurred in the Eastern Cape Province especially in the northern and southern neotectonic belts. The central part located north of the southern neotectonic belt and south of the northern neotectonic belt is inactive. This inactive zone can be considered for the storage of nuclear wastes. 2) The eastern neotectonic belt has, like the northern neotectonic belt, a higher density of lineaments oriented northwest-southeast, which makes it the second important neotectonic belt. These lineaments correlate with the normalized difference vegetation index indicative of a good circulation of groundwater. In the south, the Eastern Cape great lineament oriented east-west is now considered a neotectonic domain because many seismic epicentres occur therein. Its geomorphologic shape in graben type form is a favourable structure for groundwater catchment. The surface topography is not uniform and high elevations in the east are related to the uplift that took place in the Quaternary. Most vector gradients are oriented east-west, a fact to be reckon with in the study of surface water flow and aquifers characterization. 3) Offshore along the east coast, the subsurface is affected by neotectonic faults, which are probably splays of the Agulhas Falkland Fractured Zone (AFFZ). The folds that occur are related to the regional compressional stress known as the Wegener Stress Anomaly (WSM). On land, straight lines from seismic profiles indicate that weathering occurs in consolidated materials probably along faults or fractures, unconsolidated sediments always have wavy profiles. On the other hand, field observations in King Williams Town have clearly shown that a tectonic uplift took place on a dolerite sill overlain by mudstones and sandstones. The uplift is possibly related to the Amatole-Swaziland event that occurred in the last five millions years. The escarpment along this dolerite sill overlain by sedimentary rocks is a meso-scale fault with a dip-slip component. Healthy vegetation and a river flowing parallel to the cliff indicate groundwater flow in the zone of weakness. 4) In the southern neotectonic belt there is a clear northwest-southeast horizontal compression and a southwest-northeast vertical to sub-vertical extension. Enrichment of granitic breccias and feldspar in the Grahamstown Dwyka tillite is the source for the formation of kaolin deposits. The weathering starts in the granitic breccias through their extensional fractures and then extends in the matrix, which has micro-fractures that are only visible with the transmitted microscope. Combined extensional strike-slip and dip-slip faulting is responsible for the earthquakes in the region of Grahamstown where the kaolin is formed. There is also an unreported thermal (quartz veins) and neotectonic event identified in this region. 5) The hot springs in the northern neotectonic belt are connected by a regional neotectonic fault. The use of magnetic and electromagnetic methods helped to decipher the occurrence of faults, fractures, dolerite dykes, and variable degree of weathering. Uranium/potassium ratios derived from radiometric surveys show that areas around some hot springs are characterized by enrichment in uranium. High concentrations of thorium are related to its low capacity of being easily dissolved in water. It can be concluded that seismicity, hot springs and accordingly deep groundwater circulation, high density of lineaments, quaternary tectonic uplift, are the predominate characteristics of the three neotectonic zones. Furthermore, on the environmental point of view, thorium concentration is higher than that of either uranium or potassium. Although it is nonetheless below the world average threshold of 7.4 ppm according to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), it may be a source of radiation hazard to humans and animals if they are subjected to prolonged exposure. All the neotectonic zones in the Eastern Cape Province present potentials to host good and important aquifers. It is suggested that the Eastern Cape great lineament in the southern neotectonic belt and the Kokstad-Koffiefontein seismic belt in the northern neotectonic belt, be monitored for future research regarding, neotectonics, seismic risk assessment and hydrogeology.
- Full Text:
- Date Issued: 2014
- Authors: Madi, Kakaba
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: vital:11530 , http://hdl.handle.net/10353/d1021270
- Description: The Eastern Cape Province has, besides the three known neotectonic belts (southern, eastern and northern) a fourth zone, which is inactive. This inactive zone is located almost in its central part north of the southern neotectonic zone, and south of the northern neotectonic belt. The three above mentioned neotectonic belts (southern, eastern and northern) were chosen for this study, each one with its own characteristics. This study aims at characterizing and targeting potentially high yield aquifers in the neotectonic zones in the Eastern Cape Province. The methods used in this study include: 1) A comprehensive literature review on neotectonics in South Africa in general and in the Eastern Cape Province in particular; 2) Extraction of lineaments through remote sensing and examination of digital elevation models; 3) Examination of seismic data for the subsurface visualization onshore and offshore; 4) Study on the genesis of the Grahamstown kaolin deposits through the structural component; and 5) Acquisition and interpretation of magnetic, electromagnetic and radiometric data from three of the hot springs in the northern neotectonic belt. The results indicate the following: 1) Old map of seismic epicentres in South Africa need to be reviewed continually. The Eastern Cape was regarded as quiescent in terms of seismicity. However, the investigation from recent seismic epicenters downloadable from the IRIS website has shown that recent seismic events occurred in the Eastern Cape Province especially in the northern and southern neotectonic belts. The central part located north of the southern neotectonic belt and south of the northern neotectonic belt is inactive. This inactive zone can be considered for the storage of nuclear wastes. 2) The eastern neotectonic belt has, like the northern neotectonic belt, a higher density of lineaments oriented northwest-southeast, which makes it the second important neotectonic belt. These lineaments correlate with the normalized difference vegetation index indicative of a good circulation of groundwater. In the south, the Eastern Cape great lineament oriented east-west is now considered a neotectonic domain because many seismic epicentres occur therein. Its geomorphologic shape in graben type form is a favourable structure for groundwater catchment. The surface topography is not uniform and high elevations in the east are related to the uplift that took place in the Quaternary. Most vector gradients are oriented east-west, a fact to be reckon with in the study of surface water flow and aquifers characterization. 3) Offshore along the east coast, the subsurface is affected by neotectonic faults, which are probably splays of the Agulhas Falkland Fractured Zone (AFFZ). The folds that occur are related to the regional compressional stress known as the Wegener Stress Anomaly (WSM). On land, straight lines from seismic profiles indicate that weathering occurs in consolidated materials probably along faults or fractures, unconsolidated sediments always have wavy profiles. On the other hand, field observations in King Williams Town have clearly shown that a tectonic uplift took place on a dolerite sill overlain by mudstones and sandstones. The uplift is possibly related to the Amatole-Swaziland event that occurred in the last five millions years. The escarpment along this dolerite sill overlain by sedimentary rocks is a meso-scale fault with a dip-slip component. Healthy vegetation and a river flowing parallel to the cliff indicate groundwater flow in the zone of weakness. 4) In the southern neotectonic belt there is a clear northwest-southeast horizontal compression and a southwest-northeast vertical to sub-vertical extension. Enrichment of granitic breccias and feldspar in the Grahamstown Dwyka tillite is the source for the formation of kaolin deposits. The weathering starts in the granitic breccias through their extensional fractures and then extends in the matrix, which has micro-fractures that are only visible with the transmitted microscope. Combined extensional strike-slip and dip-slip faulting is responsible for the earthquakes in the region of Grahamstown where the kaolin is formed. There is also an unreported thermal (quartz veins) and neotectonic event identified in this region. 5) The hot springs in the northern neotectonic belt are connected by a regional neotectonic fault. The use of magnetic and electromagnetic methods helped to decipher the occurrence of faults, fractures, dolerite dykes, and variable degree of weathering. Uranium/potassium ratios derived from radiometric surveys show that areas around some hot springs are characterized by enrichment in uranium. High concentrations of thorium are related to its low capacity of being easily dissolved in water. It can be concluded that seismicity, hot springs and accordingly deep groundwater circulation, high density of lineaments, quaternary tectonic uplift, are the predominate characteristics of the three neotectonic zones. Furthermore, on the environmental point of view, thorium concentration is higher than that of either uranium or potassium. Although it is nonetheless below the world average threshold of 7.4 ppm according to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), it may be a source of radiation hazard to humans and animals if they are subjected to prolonged exposure. All the neotectonic zones in the Eastern Cape Province present potentials to host good and important aquifers. It is suggested that the Eastern Cape great lineament in the southern neotectonic belt and the Kokstad-Koffiefontein seismic belt in the northern neotectonic belt, be monitored for future research regarding, neotectonics, seismic risk assessment and hydrogeology.
- Full Text:
- Date Issued: 2014
Taxonomy and life history of the zebra seabream, Diplodus cervinus (Perciformes: Sparidae), in southern Angola
- Authors: Winkler, Alexander Claus
- Date: 2014
- Subjects: Diplodus -- Classification Fish populations -- Angola Diplodus -- Angola Diplodus -- South Africa Diplodus -- Morphology Fisheries -- Angola Sparidae
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5361 , http://hdl.handle.net/10962/d1012062
- Description: The zebra sea bream, Diplodus cervinus (Sparidae) is an inshore fish comprised of two boreal subspecies from the Gulf of Oman and the Mediterranean / north eastern Atlantic and one austral subspecies from South Africa and southern Angola. The assumption of a single austral subspecies has, however, been questioned due to mounting molecular and morphological evidence suggesting that the cool Benguela current is a vicariant barrier that has separated many synonymous inshore fish species between South Africa and southern Angola. The aims of this thesis are to conduct a comparative morphological analysis of Diplodus cervinus in southern Angola and South Africa in order to classify the southern Angolan population and then to conduct a life history assessment to assess the life history impact of allopatry on this species between the two regions. Results of the morphological findings of the present study (ANOSIM, p < 0.05, Rmeristic = 0.42) and (Rmorphometric = 0.30) along with a concurrent molecular study (FST = 0.4 – 0.6), identified significant divergence between specimens from South Africa (n = 25) and southern Angola (n = 37) and supported stock separation and possibly sub-speciation, depending on the classification criteria utilised. While samples from the two boreal subspecies were not available for the comparative morphological or molecular analysis, comparisons of the colouration patterns between the three subspecies, suggested similarity between the southern Angola and the northern Atlantic / Mediterranean populations. In contrast, the colouration patterns between the southern Angolan and South African specimens differed substantially, further supporting the morphological and molecular results. The distinct morphological divergence between the southern Angolan and South African populations was not reflected within the life history traits of both populations. A combination of methods, including length/age frequency analyses, adult sex ratios and histological analysis was used to determine that this species is a rudimentary hermaphrodite in southern Angola. Peak spawning season was observed between June and July. The overall sex ratio (M: F) was 1:1.52 with females dominating smaller younger size classes and 50% maturity was attained at 210 mm FL and 4.6 years. Females [L(t) = 287.5(1-e⁻°·¹⁸⁽t⁻²·⁸⁴⁾)] grew significantly faster (LRT, p < 0.05) than males [L(t) = 380.19(1-e⁻°·°⁶⁽t⁻⁷·¹²⁾)]. The higher maximum age of the southern Angolan population of D. cervinus (43 years) was older than that of South African individuals sampled in the tsitsikamma national park. The similarities in the life history of the two austral populations are probably a consequence of similar selective pressures in the similar warmtemperate habitats. Evidence to support the above comments was found in the feeding study which showed that the South African and Angolan populations were almost identical, with both populations feeding primarily on amphipods and polychaete worms throughout ontogeny. In contrast, the diet of their boreal conspecifics from the Mediterranean was different, where larger individuals tended to select larger, and more robust, prey items. The life history differences observed between the boreal and austral populations can be attributed to either sampling bias or environmental factors. Sampling biases included the use of different age and growth estimation techniques, while the environmental factors would include differential selective pressures most likely driven by different resource availability and exploitation. The present study provides crucial baseline life history information of a potentially exploitable species off southern Angola as well as information on the life history plasticity of the species. Unfortunately, the current lack of uniformity in the methods used to estimate life history parameters between studies conducted on the boreal and austral populations have complicated our understanding of the evolution of various life history trends in sparid fish. From a management perspective however, the results from the present study can be used to propose management strategies for an emerging trap fishery in southern Angola. Using a balanced exploitation fishery approach (harvesting up to the size-at-100% maturity), the size of the fish traps entrance was calculated based the morphological information from this and other small sparid species that are targeted and was estimated to be 62 mm.
- Full Text:
- Date Issued: 2014
- Authors: Winkler, Alexander Claus
- Date: 2014
- Subjects: Diplodus -- Classification Fish populations -- Angola Diplodus -- Angola Diplodus -- South Africa Diplodus -- Morphology Fisheries -- Angola Sparidae
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5361 , http://hdl.handle.net/10962/d1012062
- Description: The zebra sea bream, Diplodus cervinus (Sparidae) is an inshore fish comprised of two boreal subspecies from the Gulf of Oman and the Mediterranean / north eastern Atlantic and one austral subspecies from South Africa and southern Angola. The assumption of a single austral subspecies has, however, been questioned due to mounting molecular and morphological evidence suggesting that the cool Benguela current is a vicariant barrier that has separated many synonymous inshore fish species between South Africa and southern Angola. The aims of this thesis are to conduct a comparative morphological analysis of Diplodus cervinus in southern Angola and South Africa in order to classify the southern Angolan population and then to conduct a life history assessment to assess the life history impact of allopatry on this species between the two regions. Results of the morphological findings of the present study (ANOSIM, p < 0.05, Rmeristic = 0.42) and (Rmorphometric = 0.30) along with a concurrent molecular study (FST = 0.4 – 0.6), identified significant divergence between specimens from South Africa (n = 25) and southern Angola (n = 37) and supported stock separation and possibly sub-speciation, depending on the classification criteria utilised. While samples from the two boreal subspecies were not available for the comparative morphological or molecular analysis, comparisons of the colouration patterns between the three subspecies, suggested similarity between the southern Angola and the northern Atlantic / Mediterranean populations. In contrast, the colouration patterns between the southern Angolan and South African specimens differed substantially, further supporting the morphological and molecular results. The distinct morphological divergence between the southern Angolan and South African populations was not reflected within the life history traits of both populations. A combination of methods, including length/age frequency analyses, adult sex ratios and histological analysis was used to determine that this species is a rudimentary hermaphrodite in southern Angola. Peak spawning season was observed between June and July. The overall sex ratio (M: F) was 1:1.52 with females dominating smaller younger size classes and 50% maturity was attained at 210 mm FL and 4.6 years. Females [L(t) = 287.5(1-e⁻°·¹⁸⁽t⁻²·⁸⁴⁾)] grew significantly faster (LRT, p < 0.05) than males [L(t) = 380.19(1-e⁻°·°⁶⁽t⁻⁷·¹²⁾)]. The higher maximum age of the southern Angolan population of D. cervinus (43 years) was older than that of South African individuals sampled in the tsitsikamma national park. The similarities in the life history of the two austral populations are probably a consequence of similar selective pressures in the similar warmtemperate habitats. Evidence to support the above comments was found in the feeding study which showed that the South African and Angolan populations were almost identical, with both populations feeding primarily on amphipods and polychaete worms throughout ontogeny. In contrast, the diet of their boreal conspecifics from the Mediterranean was different, where larger individuals tended to select larger, and more robust, prey items. The life history differences observed between the boreal and austral populations can be attributed to either sampling bias or environmental factors. Sampling biases included the use of different age and growth estimation techniques, while the environmental factors would include differential selective pressures most likely driven by different resource availability and exploitation. The present study provides crucial baseline life history information of a potentially exploitable species off southern Angola as well as information on the life history plasticity of the species. Unfortunately, the current lack of uniformity in the methods used to estimate life history parameters between studies conducted on the boreal and austral populations have complicated our understanding of the evolution of various life history trends in sparid fish. From a management perspective however, the results from the present study can be used to propose management strategies for an emerging trap fishery in southern Angola. Using a balanced exploitation fishery approach (harvesting up to the size-at-100% maturity), the size of the fish traps entrance was calculated based the morphological information from this and other small sparid species that are targeted and was estimated to be 62 mm.
- Full Text:
- Date Issued: 2014
Teacher conversations : what happens when teachers talk
- Authors: Klitsie, Clara
- Date: 2014
- Subjects: Communication in education , Interaction analysis in education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9457 , http://hdl.handle.net/10948/d1020081
- Description: Teaching has a primary focus on engagement with students, but paradoxically, it can be experienced as lonely, private work, in classrooms behind closed doors, with an accompanying sense of deep disconnection from peers. When six experienced teachers sought to counteract this isolation, they formed a group which embarked on a shared journey of reflection and conversation, with the purpose of increasing selfknowledge, clarifying a sense of self as teacher, extending understanding of the selfhood of other teachers, and exposing the deeper sources of meaning underlying the vocation of teacher. This study sought to describe the information, opinions and beliefs which were exchanged among participants within the group and to describe the dynamics within the group. Furthermore, it sought to identify and describe the self-perceived impact of the experience of such a group, on the vocational vitality of each of the participants. Within an interpretivist epistemology a qualitative phenomenological research approach was adopted for the study. Data were obtained from two sources, consisting of transcripts of conversations from the meetings of a collaborative reflective group and from semi-structured individual interviews with group participants. These were analysed using an inductive approach with the aid of qualitative data analysis software: Atlas ti®. Findings from the study show that a high level of trust and a sense of safety were created through the use of guiding principles for meetings. Content chosen for reflective conversations and the general experience of meetings was perceived as providing a rare opportunity for participants to discover their selfhood as teachers. They reported that this understanding was further broadened by exposure to the selfhood of other teachers. Furthermore, members of the talk group reported that participation had resulted in a lowering of their sense of professional isolation and a renewal of vitality in their teaching. It is hoped that the findings from the study will inform an understanding of the experience of dialogue in a reflective, peer group where teachers focus on exploring together “who they are” as teachers. It provides valuable insights of the personal and professional transformations which can take place for teachers participating in conversations which focus on their inner landscape. Furthermore, the study has the potential to inform South African teacher professional development programmes with approaches which focus on teacher vocational renewal and vitality.
- Full Text:
- Date Issued: 2014
- Authors: Klitsie, Clara
- Date: 2014
- Subjects: Communication in education , Interaction analysis in education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9457 , http://hdl.handle.net/10948/d1020081
- Description: Teaching has a primary focus on engagement with students, but paradoxically, it can be experienced as lonely, private work, in classrooms behind closed doors, with an accompanying sense of deep disconnection from peers. When six experienced teachers sought to counteract this isolation, they formed a group which embarked on a shared journey of reflection and conversation, with the purpose of increasing selfknowledge, clarifying a sense of self as teacher, extending understanding of the selfhood of other teachers, and exposing the deeper sources of meaning underlying the vocation of teacher. This study sought to describe the information, opinions and beliefs which were exchanged among participants within the group and to describe the dynamics within the group. Furthermore, it sought to identify and describe the self-perceived impact of the experience of such a group, on the vocational vitality of each of the participants. Within an interpretivist epistemology a qualitative phenomenological research approach was adopted for the study. Data were obtained from two sources, consisting of transcripts of conversations from the meetings of a collaborative reflective group and from semi-structured individual interviews with group participants. These were analysed using an inductive approach with the aid of qualitative data analysis software: Atlas ti®. Findings from the study show that a high level of trust and a sense of safety were created through the use of guiding principles for meetings. Content chosen for reflective conversations and the general experience of meetings was perceived as providing a rare opportunity for participants to discover their selfhood as teachers. They reported that this understanding was further broadened by exposure to the selfhood of other teachers. Furthermore, members of the talk group reported that participation had resulted in a lowering of their sense of professional isolation and a renewal of vitality in their teaching. It is hoped that the findings from the study will inform an understanding of the experience of dialogue in a reflective, peer group where teachers focus on exploring together “who they are” as teachers. It provides valuable insights of the personal and professional transformations which can take place for teachers participating in conversations which focus on their inner landscape. Furthermore, the study has the potential to inform South African teacher professional development programmes with approaches which focus on teacher vocational renewal and vitality.
- Full Text:
- Date Issued: 2014
Teacher conversations: what happens when teachers talk
- Authors: Klitsie, Clara
- Date: 2014
- Subjects: Communication in education , Interaction analysis in education , Teachers -- Training of
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9589 , http://hdl.handle.net/10948/d1021080
- Description: Teaching has a primary focus on engagement with students, but paradoxically, it can be experienced as lonely, private work, in classrooms behind closed doors, with an accompanying sense of deep disconnection from peers. When six experienced teachers sought to counteract this isolation, they formed a group which embarked on a shared journey of reflection and conversation, with the purpose of increasing selfknowledge, clarifying a sense of self as teacher, extending understanding of the selfhood of other teachers, and exposing the deeper sources of meaning underlying the vocation of teacher. This study sought to describe the information, opinions and beliefs which were exchanged among participants within the group and to describe the dynamics within the group. Furthermore, it sought to identify and describe the self-perceived impact of the experience of such a group, on the vocational vitality of each of the participants. Within an interpretivist epistemology a qualitative phenomenological research approach was adopted for the study. Data were obtained from two sources, consisting of transcripts of conversations from the meetings of a collaborative reflective group and from semi-structured individual interviews with group participants. These were analysed using an inductive approach with the aid of qualitative data analysis software: Atlas ti®. Findings from the study show that a high level of trust and a sense of safety were created through the use of guiding principles for meetings. Content chosen for reflective conversations and the general experience of meetings was perceived as providing a rare opportunity for participants to discover their selfhood as teachers. They reported that this understanding was further broadened by exposure to the selfhood of other teachers. Furthermore, members of the talk group reported that participation had resulted in a lowering of their sense of professional isolation and a renewal of vitality in their teaching.
- Full Text:
- Date Issued: 2014
- Authors: Klitsie, Clara
- Date: 2014
- Subjects: Communication in education , Interaction analysis in education , Teachers -- Training of
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9589 , http://hdl.handle.net/10948/d1021080
- Description: Teaching has a primary focus on engagement with students, but paradoxically, it can be experienced as lonely, private work, in classrooms behind closed doors, with an accompanying sense of deep disconnection from peers. When six experienced teachers sought to counteract this isolation, they formed a group which embarked on a shared journey of reflection and conversation, with the purpose of increasing selfknowledge, clarifying a sense of self as teacher, extending understanding of the selfhood of other teachers, and exposing the deeper sources of meaning underlying the vocation of teacher. This study sought to describe the information, opinions and beliefs which were exchanged among participants within the group and to describe the dynamics within the group. Furthermore, it sought to identify and describe the self-perceived impact of the experience of such a group, on the vocational vitality of each of the participants. Within an interpretivist epistemology a qualitative phenomenological research approach was adopted for the study. Data were obtained from two sources, consisting of transcripts of conversations from the meetings of a collaborative reflective group and from semi-structured individual interviews with group participants. These were analysed using an inductive approach with the aid of qualitative data analysis software: Atlas ti®. Findings from the study show that a high level of trust and a sense of safety were created through the use of guiding principles for meetings. Content chosen for reflective conversations and the general experience of meetings was perceived as providing a rare opportunity for participants to discover their selfhood as teachers. They reported that this understanding was further broadened by exposure to the selfhood of other teachers. Furthermore, members of the talk group reported that participation had resulted in a lowering of their sense of professional isolation and a renewal of vitality in their teaching.
- Full Text:
- Date Issued: 2014
Teachers' perceptions of behavioural problems manifested by Grade 11 and 12 learners in three Namibian schools
- Authors: Akawa, Ester Anna Nelago
- Date: 2014
- Subjects: Education, Secondary -- Namibia School children -- Namibia -- Attitudes Learning disabilities -- Social aspects Behavior disorders in children -- Education (Secondary) -- Namibia Children with social disabilities -- Education (Secondary) -- Namibia Emotional problems of children -- Education (Secondary) -- Namibia Teachers -- Job stress -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1962 , http://hdl.handle.net/10962/d1010868
- Description: In Namibia today few learners with behavioural and learning problems are within special schools as most are placed within the mainstream school system. Placing these learners within the mainstream system is part of the policy of Inclusive Education (IE) because it argues that this would benefit these learners and also save resources. IE is concerned with addressing barriers to learning and behavioural problems are regarded as one of these barriers. IE argues for a series of new approaches to the diagnosis and response to learners with behavioural problems. This poses challenges for teachers in mainstream schools. Teachers are at the forefront of this situation as they are usually the first to observe and experience the behavioural problems in the schools and are expected to respond appropriately. They find this situation both challenging and problematic. This research explores a sample of teachers’ perceptions of learners’ behavioural problems. To collect in-depth information, this study followed a qualitative approach with a case study design. The data were collected through semi-structured interviews, supplemented with observation and document analysis. The study consisted of fifteen respondents: three principals, three teacher counsellors and nine teachers from the three selected schools. This study illuminates the types of behaviour that teachers encounter, the impact of these behaviours, the factors seen as contributing to these behaviours, and how teachers and the school system deal with these behaviours. In addition the study applies Bronfenbrenner’s bioecological model (1992) to explain how the behaviours manifested by Grade 11 and 12 learners, and identified as problematic by teachers, are part of an interconnected nested social system. The results from the study indicate the manifestation of behavioural problems to be common occurrences in secondary schools are evident, amongst others, through fighting, bullying, substance abuse, truancy, and disrespect of teachers and authority. The teachers pointed to the prevalence of these problems as well as the serious impact such problems have on these learners, their fellow learners, and on the teachers. The teachers identified a complex array of what they saw as contributing factors located within the school, peer groups, family and home circumstances, the local community, as well within the national education policy, the economy and society. The study points to some specific, as well as broader, lessons and opportunities for action both for those managing the education system at the national level and for schools and teachers.
- Full Text:
- Date Issued: 2014
- Authors: Akawa, Ester Anna Nelago
- Date: 2014
- Subjects: Education, Secondary -- Namibia School children -- Namibia -- Attitudes Learning disabilities -- Social aspects Behavior disorders in children -- Education (Secondary) -- Namibia Children with social disabilities -- Education (Secondary) -- Namibia Emotional problems of children -- Education (Secondary) -- Namibia Teachers -- Job stress -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1962 , http://hdl.handle.net/10962/d1010868
- Description: In Namibia today few learners with behavioural and learning problems are within special schools as most are placed within the mainstream school system. Placing these learners within the mainstream system is part of the policy of Inclusive Education (IE) because it argues that this would benefit these learners and also save resources. IE is concerned with addressing barriers to learning and behavioural problems are regarded as one of these barriers. IE argues for a series of new approaches to the diagnosis and response to learners with behavioural problems. This poses challenges for teachers in mainstream schools. Teachers are at the forefront of this situation as they are usually the first to observe and experience the behavioural problems in the schools and are expected to respond appropriately. They find this situation both challenging and problematic. This research explores a sample of teachers’ perceptions of learners’ behavioural problems. To collect in-depth information, this study followed a qualitative approach with a case study design. The data were collected through semi-structured interviews, supplemented with observation and document analysis. The study consisted of fifteen respondents: three principals, three teacher counsellors and nine teachers from the three selected schools. This study illuminates the types of behaviour that teachers encounter, the impact of these behaviours, the factors seen as contributing to these behaviours, and how teachers and the school system deal with these behaviours. In addition the study applies Bronfenbrenner’s bioecological model (1992) to explain how the behaviours manifested by Grade 11 and 12 learners, and identified as problematic by teachers, are part of an interconnected nested social system. The results from the study indicate the manifestation of behavioural problems to be common occurrences in secondary schools are evident, amongst others, through fighting, bullying, substance abuse, truancy, and disrespect of teachers and authority. The teachers pointed to the prevalence of these problems as well as the serious impact such problems have on these learners, their fellow learners, and on the teachers. The teachers identified a complex array of what they saw as contributing factors located within the school, peer groups, family and home circumstances, the local community, as well within the national education policy, the economy and society. The study points to some specific, as well as broader, lessons and opportunities for action both for those managing the education system at the national level and for schools and teachers.
- Full Text:
- Date Issued: 2014
Teachers’ experiences of change : a case study analysis of a school-based intervention in rural Kwazulu-Natal
- Authors: James, Sally Jane
- Date: 2014
- Subjects: David Rattray Foundation , Educational change -- South Africa -- KwaZulu-Natal -- Case studies , Rural schools -- South Africa -- KwaZulu-Natal , Teachers -- Training of -- South Africa -- KwaZulu-Natal , Community and school -- South Africa -- KwaZulu-Natal , KwaZulu-Natal (South Africa) -- Social conditions , KwaZulu-Natal (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1980 , http://hdl.handle.net/10962/d1013118
- Description: The research presented in this thesis is a case study analysis of the school-based intervention initiated by the David Rattray Foundation [DRF]. David Rattray, a South African historian well known for his contribution to the 1879-1896 Anglo-Zulu War heritage, was murdered in January 2007. In response to his untimely death, the DRF was established by family and friends with the hope of improving education within the Umzinyathi rural municipal district of KwaZulu-Natal. This study consisted of three phases: Phase I (May-December 2011); Phase II (January-December 2012), and Phase III (December 2012-October 2013). During Phase I, the focus was on describing the broader context in which the case is located. It resulted in a narrative account of the emergence of the DRF as a non-governmental organisation [NGO] working towards change within the local rural school community. During Phase II the focus shifted from the broader socio-political and economic context to the human dimension which included teachers, principals, volunteer workers and a district official working in the schools. During Phase II the approach to change adopted by the DRF was critically analysed in relation to models of change described in the literature. Teachers’ experiences of change were also examined. Phase III was a synthesis of the findings from the first two research phases. By drawing on systems and complexity theory perspectives, insights were gained enabling a deep understanding of the DRF’s school-based intervention as a whole. This research is a qualitative study that seeks to understand individual teachers’ experiences and participation in a process of change that reaches beyond the individual and his/her immediate context. The adoption of a realist ontology (Maxwell, 2012) and application of an explanatory heuristic based on the critical realist philosophy of Bhaskar (1979, 1980, 2011) enabled the layered analysis and in-depth interpretation that characterises the study. The findings of the study reveal a complex and ongoing process of change within a rural school context. The results illuminate the efficacy of a collaborative partnership between civil society (the DRF), the local community, under the leadership of a tribal authority, and the local government (KwaZulu-Natal Provincial Department of Education). It also reveals how teachers within this particular context do not have a strong voice in the change process and hence participate only superficially in the school-based intervention. It is probable that the constraining mechanisms revealed through this research are not exclusive to this particular case study, but are common across the South African rural school context. The main contention of this thesis is that these mechanisms need further interrogation in order to enable further change and permit the active participation of teachers in the process.While the study illuminates many of the tensions and problems faced by the schools and the community in which they are located, it also highlights the achievements and selfless attitude of many people working towards change and improvement within the schools. This case study thus provides an example to all South Africans of what can be achieved with commitment and effort.
- Full Text:
- Date Issued: 2014
- Authors: James, Sally Jane
- Date: 2014
- Subjects: David Rattray Foundation , Educational change -- South Africa -- KwaZulu-Natal -- Case studies , Rural schools -- South Africa -- KwaZulu-Natal , Teachers -- Training of -- South Africa -- KwaZulu-Natal , Community and school -- South Africa -- KwaZulu-Natal , KwaZulu-Natal (South Africa) -- Social conditions , KwaZulu-Natal (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1980 , http://hdl.handle.net/10962/d1013118
- Description: The research presented in this thesis is a case study analysis of the school-based intervention initiated by the David Rattray Foundation [DRF]. David Rattray, a South African historian well known for his contribution to the 1879-1896 Anglo-Zulu War heritage, was murdered in January 2007. In response to his untimely death, the DRF was established by family and friends with the hope of improving education within the Umzinyathi rural municipal district of KwaZulu-Natal. This study consisted of three phases: Phase I (May-December 2011); Phase II (January-December 2012), and Phase III (December 2012-October 2013). During Phase I, the focus was on describing the broader context in which the case is located. It resulted in a narrative account of the emergence of the DRF as a non-governmental organisation [NGO] working towards change within the local rural school community. During Phase II the focus shifted from the broader socio-political and economic context to the human dimension which included teachers, principals, volunteer workers and a district official working in the schools. During Phase II the approach to change adopted by the DRF was critically analysed in relation to models of change described in the literature. Teachers’ experiences of change were also examined. Phase III was a synthesis of the findings from the first two research phases. By drawing on systems and complexity theory perspectives, insights were gained enabling a deep understanding of the DRF’s school-based intervention as a whole. This research is a qualitative study that seeks to understand individual teachers’ experiences and participation in a process of change that reaches beyond the individual and his/her immediate context. The adoption of a realist ontology (Maxwell, 2012) and application of an explanatory heuristic based on the critical realist philosophy of Bhaskar (1979, 1980, 2011) enabled the layered analysis and in-depth interpretation that characterises the study. The findings of the study reveal a complex and ongoing process of change within a rural school context. The results illuminate the efficacy of a collaborative partnership between civil society (the DRF), the local community, under the leadership of a tribal authority, and the local government (KwaZulu-Natal Provincial Department of Education). It also reveals how teachers within this particular context do not have a strong voice in the change process and hence participate only superficially in the school-based intervention. It is probable that the constraining mechanisms revealed through this research are not exclusive to this particular case study, but are common across the South African rural school context. The main contention of this thesis is that these mechanisms need further interrogation in order to enable further change and permit the active participation of teachers in the process.While the study illuminates many of the tensions and problems faced by the schools and the community in which they are located, it also highlights the achievements and selfless attitude of many people working towards change and improvement within the schools. This case study thus provides an example to all South Africans of what can be achieved with commitment and effort.
- Full Text:
- Date Issued: 2014
Teachers’ understanding and implementation of inclusive education in an Eastern Cape primary school
- Authors: Mcconnachie, Karola
- Date: 2014
- Subjects: Inclusive education -- South Africa , Special education -- South Africa , Education (Primary) -- Government policy -- South Africa , Alcoholism -- Social aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1984 , http://hdl.handle.net/10962/d1013150
- Description: Since 2001 the South African Department of Basic Education has been working towards implementing Inclusive Education over a twenty year period. This is in accordance with international trends in education. This study set out to investigate the implementation of Inclusive Education in a South African context by conducting a case study at an Eastern Cape no‐fee‐paying primary school. It looked at how the government policy, as set out in Education White Paper 6 (EWP6) (DoE, 2001), is understood and being implemented by teachers at the Welcome Primary school. The study further investigated the introduction of the National Strategy on Screening, Identification, Assessment and Support (SIAS strategy) (DoE, 2008a) to gain insight into how teachers identify and assess barriers to learning in an ordinary primary school. In addition it looked at emerging factors that could impact on the implementation of this policy. With 16 years teaching experience in ordinary and private schools and 19 years experience in a special needs school as a teacher, head of department and then principal, I have personal experience of the crisis in the Eastern Cape Department of Basic Education. This awareness provided the impetus and interest in researching Inclusive Education policy implementation. It is my view that only when we begin to grapple with the problems right at the source of the education crisis within the majority of the no‐fee‐paying schools that informed decisions about policy and policy implementation can be made. As I am able to understand and converse in isiXhosa, I was able to observe and experience the implementation of EWP6 and the SIAS strategy in a school that is an isiXhosa‐medium ordinary primary school and similar to the majority of ordinary public schools in the district. A qualitative research approach based within an interpretive paradigm using the case study method was used for this study. Semi‐structured interviews, detailed field notes as well as documents generated by meetings and education conferences helped me to investigate and refine my research goals. The research found that the implementation of EWP6 and the SIAS strategy posed a major challenge for the Department of Basic Education, and highlighted the significant gap between ordinary primary schools and special needs schools. However, the fact that there is a partial engagement with the process of providing inclusive education, does present some measure of hope for a better future for those learners that have experienced the injustice of exclusion from education and society. The Eastern Cape Department of Basic Education will have to ‘catch up’ to other provinces in its delivery of every child’s constitutional right to education in an inclusive school environment. Factors emerged from the study that showed that the assessment of learners’ barriers to learning with the resultant support needs was a relatively new concept, as teachers tended to rely on traditional classroom tests and simple informal classroom assessments to assess the learners. Teachers expressed a good verbal knowledge of learners with support needs but found it very challenging to put this verbal knowledge into a written document. In addition there was inadequate support from the District Based Support Team to implement the SIAS strategy. This study showed that the medical model of assessment was still being adhered to in the research district with little evidence of a move to a social model of assessment in terms of the SIAS strategy. In addition, factors emerged indicating the serious impact that alcohol abuse has on children and the society in which they live. The evidence of increasing numbers of children with Fetal Alcohol Spectrum Disorder (FASD) in a single educational district is a matter of grave concern from an educational and financial perspective. It is my contention that this is a matter of national urgency and that the Department of Basic Education must confront the escalating problem of alcohol abuse and the resultant challenges of a large number of learners with serious barriers to learning that need to be included in the education system.
- Full Text:
- Date Issued: 2014
- Authors: Mcconnachie, Karola
- Date: 2014
- Subjects: Inclusive education -- South Africa , Special education -- South Africa , Education (Primary) -- Government policy -- South Africa , Alcoholism -- Social aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1984 , http://hdl.handle.net/10962/d1013150
- Description: Since 2001 the South African Department of Basic Education has been working towards implementing Inclusive Education over a twenty year period. This is in accordance with international trends in education. This study set out to investigate the implementation of Inclusive Education in a South African context by conducting a case study at an Eastern Cape no‐fee‐paying primary school. It looked at how the government policy, as set out in Education White Paper 6 (EWP6) (DoE, 2001), is understood and being implemented by teachers at the Welcome Primary school. The study further investigated the introduction of the National Strategy on Screening, Identification, Assessment and Support (SIAS strategy) (DoE, 2008a) to gain insight into how teachers identify and assess barriers to learning in an ordinary primary school. In addition it looked at emerging factors that could impact on the implementation of this policy. With 16 years teaching experience in ordinary and private schools and 19 years experience in a special needs school as a teacher, head of department and then principal, I have personal experience of the crisis in the Eastern Cape Department of Basic Education. This awareness provided the impetus and interest in researching Inclusive Education policy implementation. It is my view that only when we begin to grapple with the problems right at the source of the education crisis within the majority of the no‐fee‐paying schools that informed decisions about policy and policy implementation can be made. As I am able to understand and converse in isiXhosa, I was able to observe and experience the implementation of EWP6 and the SIAS strategy in a school that is an isiXhosa‐medium ordinary primary school and similar to the majority of ordinary public schools in the district. A qualitative research approach based within an interpretive paradigm using the case study method was used for this study. Semi‐structured interviews, detailed field notes as well as documents generated by meetings and education conferences helped me to investigate and refine my research goals. The research found that the implementation of EWP6 and the SIAS strategy posed a major challenge for the Department of Basic Education, and highlighted the significant gap between ordinary primary schools and special needs schools. However, the fact that there is a partial engagement with the process of providing inclusive education, does present some measure of hope for a better future for those learners that have experienced the injustice of exclusion from education and society. The Eastern Cape Department of Basic Education will have to ‘catch up’ to other provinces in its delivery of every child’s constitutional right to education in an inclusive school environment. Factors emerged from the study that showed that the assessment of learners’ barriers to learning with the resultant support needs was a relatively new concept, as teachers tended to rely on traditional classroom tests and simple informal classroom assessments to assess the learners. Teachers expressed a good verbal knowledge of learners with support needs but found it very challenging to put this verbal knowledge into a written document. In addition there was inadequate support from the District Based Support Team to implement the SIAS strategy. This study showed that the medical model of assessment was still being adhered to in the research district with little evidence of a move to a social model of assessment in terms of the SIAS strategy. In addition, factors emerged indicating the serious impact that alcohol abuse has on children and the society in which they live. The evidence of increasing numbers of children with Fetal Alcohol Spectrum Disorder (FASD) in a single educational district is a matter of grave concern from an educational and financial perspective. It is my contention that this is a matter of national urgency and that the Department of Basic Education must confront the escalating problem of alcohol abuse and the resultant challenges of a large number of learners with serious barriers to learning that need to be included in the education system.
- Full Text:
- Date Issued: 2014
Teaching in higher education
- Authors: Quinn, Lynn
- Date: 2014
- Language: English
- Type: text , review
- Identifier: http://hdl.handle.net/10962/66557 , vital:28963 , https://doi.org/10.1080/1360144X.2014.908094
- Description: publisher version , As Becker and Denicolo point out in their introduction, traditionally most lecturers in higher education begin teaching with little or no formal training: ‘It is assumed if you were expert in your field you would be able, by some ill-defined means, to teach others’ (p. 1). This book aims to remedy that situation and does exactly what it sets out to do: it provides a useful, step-by-step training guide for teachers in higher education. It provides much needed advice for new academics for ways in which they can successfully combine their teaching and their research roles. It is written in an accessible style, draws on the experiences of people who have taught in higher education for some time, and provides practical advice for teaching in a range of contexts and for dealing with different challenges that may arise.
- Full Text: false
- Date Issued: 2014
- Authors: Quinn, Lynn
- Date: 2014
- Language: English
- Type: text , review
- Identifier: http://hdl.handle.net/10962/66557 , vital:28963 , https://doi.org/10.1080/1360144X.2014.908094
- Description: publisher version , As Becker and Denicolo point out in their introduction, traditionally most lecturers in higher education begin teaching with little or no formal training: ‘It is assumed if you were expert in your field you would be able, by some ill-defined means, to teach others’ (p. 1). This book aims to remedy that situation and does exactly what it sets out to do: it provides a useful, step-by-step training guide for teachers in higher education. It provides much needed advice for new academics for ways in which they can successfully combine their teaching and their research roles. It is written in an accessible style, draws on the experiences of people who have taught in higher education for some time, and provides practical advice for teaching in a range of contexts and for dealing with different challenges that may arise.
- Full Text: false
- Date Issued: 2014
Teaching strategies to improve the writing skills for grade and 9 learners in English first additional language: a case study of Forth High School in the Cradock Education district
- Authors: Kalipha, Zimkhitha
- Date: 2014
- Subjects: Teaching strategies -- writing skills , Writing skills -- Study and teaching -- South Africa , English language -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16215 , http://hdl.handle.net/10353/d1017297 , Teaching strategies -- writing skills , Writing skills -- Study and teaching -- South Africa , English language -- Study and teaching -- South Africa
- Description: Writing skills is are an essential requirement to lifelong learner success yet the way teachers teach and provide feedback to their learners on writing is quite challenging. This study sought to explore the teaching strategies to improve writing skills as an essential requirement for effective learning in schools for grade 8 and 9 learners in English First Additional Language. For people living in the townships and rural areas in South Africa, exposure to English is limited, because the majority of people communicate with each other in local languages. With teachers and learners residing in the townships where communication occurs mostly in isiXhosa, problems in language proficiency, in particular writing in English First Additional Language, are often encountered not only by the learners, but by educators as well. This was a case study of four high schools in the Cradock Education District. In-depth interviews were conducted with eight participants in the four schools. There were eight main findings, which are as follows: Lack of support for teachers, lack of a culture of learning amongst learners, and lack of competence in English for both learners and parents, which need to be addressed; and strategies proposed to improve writing skills are: the importance of creative writing; regular feedback and the importance of drafts.
- Full Text:
- Date Issued: 2014
- Authors: Kalipha, Zimkhitha
- Date: 2014
- Subjects: Teaching strategies -- writing skills , Writing skills -- Study and teaching -- South Africa , English language -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16215 , http://hdl.handle.net/10353/d1017297 , Teaching strategies -- writing skills , Writing skills -- Study and teaching -- South Africa , English language -- Study and teaching -- South Africa
- Description: Writing skills is are an essential requirement to lifelong learner success yet the way teachers teach and provide feedback to their learners on writing is quite challenging. This study sought to explore the teaching strategies to improve writing skills as an essential requirement for effective learning in schools for grade 8 and 9 learners in English First Additional Language. For people living in the townships and rural areas in South Africa, exposure to English is limited, because the majority of people communicate with each other in local languages. With teachers and learners residing in the townships where communication occurs mostly in isiXhosa, problems in language proficiency, in particular writing in English First Additional Language, are often encountered not only by the learners, but by educators as well. This was a case study of four high schools in the Cradock Education District. In-depth interviews were conducted with eight participants in the four schools. There were eight main findings, which are as follows: Lack of support for teachers, lack of a culture of learning amongst learners, and lack of competence in English for both learners and parents, which need to be addressed; and strategies proposed to improve writing skills are: the importance of creative writing; regular feedback and the importance of drafts.
- Full Text:
- Date Issued: 2014
Teaching Without Technology
- Authors: Machanick, Philip
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439238 , vital:73558 , https://homes.cs.ru.ac.za/philip/Publications/_SACLA/teachWOtech-2014.pdf
- Description: Technology is touted as a solution to problems in education. But is it? I report here on experiences with dropping use of slides in lectures and returning to working on the board. The apparent result is more interactive, engaged classes. Unfortunately there are too many other variables to make the experiences here definitive. The purpose of this paper is to provoke discussion on whether technology is overused in teaching when the goals of improving student engagement and general effectiveness of learning can be met many ways. Technology is not necessarily bad, but making it the starting point risks locking out nontechnological options.
- Full Text:
- Date Issued: 2014
- Authors: Machanick, Philip
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439238 , vital:73558 , https://homes.cs.ru.ac.za/philip/Publications/_SACLA/teachWOtech-2014.pdf
- Description: Technology is touted as a solution to problems in education. But is it? I report here on experiences with dropping use of slides in lectures and returning to working on the board. The apparent result is more interactive, engaged classes. Unfortunately there are too many other variables to make the experiences here definitive. The purpose of this paper is to provoke discussion on whether technology is overused in teaching when the goals of improving student engagement and general effectiveness of learning can be met many ways. Technology is not necessarily bad, but making it the starting point risks locking out nontechnological options.
- Full Text:
- Date Issued: 2014
Teaching writing to Grade 5 English language learners in two Grahamstown East schools, South Africa : a case study
- Authors: Julius, Lukas Homateni
- Date: 2014
- Subjects: English language -- Study and teaching (Primary) -- South Africa -- Grahamstown English language -- Written English English language -- Composition and exercises -- Study and teaching (Primary) English language -- Ability testing Teacher effectiveness -- South Africa -- Grahamstown Teachers -- Rating of -- South Africa -- Grahamstown Written communication Second language acquisition
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1971 , http://hdl.handle.net/10962/d1011989
- Description: The majority of learners in South Africa are not native speakers of English, yet English is the dominant language of learning and teaching (LoLT). South African teachers, therefore, have the challenge of ensuring that their learners' literacy skills in English are adequately developed so as to facilitate learning in other curricular areas. This study investigated the way in which two Grade 5 teachers employed at different primary schools in the Eastern Cape province of South Africa taught writing to their English first additional language (EFAL) learners. English is the LoLT at both schools. A qualitative interpretive approach was used to identify factors that shape the ways these teachers handle the teaching of writing. The theoretical framework was informed by Borg's model of teacher cognition (2003) Shulman's conception of teacher knowledge (1987). Data collection methods consisted of interviews, classroom observations and document analysis. In-depth interviews, comprising two semi-structured interviews, two post-lesson informal conversational interviews and one stimulated recall interview were conducted with each teacher. Five of each teacher's writing lessons were observed and audio and video recorded. Samples of learners' written work were also collected. Analysis of the data reveals that the two teachers' beliefs, their experiences as learners themselves and subsequently as teachers, impacted on their pedagogy, as did other contextual factors (including the support they received from subject advisors, time management, and the number and range of learners in their classrooms). It was found that both teachers focused primarily on ensuring that their learners completed their written work so that it could be marked and graded in response to demands from their superiors, rather than on engaging deeply with the processes of writing (brainstorming, drafting, revising etc). Not only does this run counter to the writing pedagogy recommended in the Curriculum and Assessment Policy Statements (CAPS), but it also denies learners the scaffolding needed to help them develop the self-regulation skills needed to become independent writers. These findings demonstrate the need for assisting teachers to shift away from focusing only on learners' performance (testing and grading) towards a stronger emphasis on the process of writing. This would require that teachers develop a deeper understanding of the process/genre approaches to teaching writing advocated by CAPS.
- Full Text:
- Date Issued: 2014
- Authors: Julius, Lukas Homateni
- Date: 2014
- Subjects: English language -- Study and teaching (Primary) -- South Africa -- Grahamstown English language -- Written English English language -- Composition and exercises -- Study and teaching (Primary) English language -- Ability testing Teacher effectiveness -- South Africa -- Grahamstown Teachers -- Rating of -- South Africa -- Grahamstown Written communication Second language acquisition
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1971 , http://hdl.handle.net/10962/d1011989
- Description: The majority of learners in South Africa are not native speakers of English, yet English is the dominant language of learning and teaching (LoLT). South African teachers, therefore, have the challenge of ensuring that their learners' literacy skills in English are adequately developed so as to facilitate learning in other curricular areas. This study investigated the way in which two Grade 5 teachers employed at different primary schools in the Eastern Cape province of South Africa taught writing to their English first additional language (EFAL) learners. English is the LoLT at both schools. A qualitative interpretive approach was used to identify factors that shape the ways these teachers handle the teaching of writing. The theoretical framework was informed by Borg's model of teacher cognition (2003) Shulman's conception of teacher knowledge (1987). Data collection methods consisted of interviews, classroom observations and document analysis. In-depth interviews, comprising two semi-structured interviews, two post-lesson informal conversational interviews and one stimulated recall interview were conducted with each teacher. Five of each teacher's writing lessons were observed and audio and video recorded. Samples of learners' written work were also collected. Analysis of the data reveals that the two teachers' beliefs, their experiences as learners themselves and subsequently as teachers, impacted on their pedagogy, as did other contextual factors (including the support they received from subject advisors, time management, and the number and range of learners in their classrooms). It was found that both teachers focused primarily on ensuring that their learners completed their written work so that it could be marked and graded in response to demands from their superiors, rather than on engaging deeply with the processes of writing (brainstorming, drafting, revising etc). Not only does this run counter to the writing pedagogy recommended in the Curriculum and Assessment Policy Statements (CAPS), but it also denies learners the scaffolding needed to help them develop the self-regulation skills needed to become independent writers. These findings demonstrate the need for assisting teachers to shift away from focusing only on learners' performance (testing and grading) towards a stronger emphasis on the process of writing. This would require that teachers develop a deeper understanding of the process/genre approaches to teaching writing advocated by CAPS.
- Full Text:
- Date Issued: 2014
Temporal and spatial variability in the abundance, biomass and distribution of Palaemon peringueyi (Decapoda: Crustacea) are influenced by biological but not physico-chemical factors in the permanently open Kariega Estuary, South Africa
- Nyalungu, Nonhlanhla P, Hodgson, Alan N, Froneman, P William, Dopolo, M, Masubelele, M
- Authors: Nyalungu, Nonhlanhla P , Hodgson, Alan N , Froneman, P William , Dopolo, M , Masubelele, M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68106 , vital:29200 , https://doi.org/10.2989/16085914.2014.960792
- Description: Publisher version , Biological and physico-chemical factors affecting abundance and biomass of shrimp Palaemon peringueyi were investigated in 2010–2011 in the lower, middle and upper reaches of the freshwater-deprived permanently open Kariega Estuary. Shrimp abundance and biomass ranged from 0 to 88 ind. m−2 and 0 to 4.4 g wwt m−2, respectively. Shrimps were most abundant in the lower reach, and highest abundances and biomasses were recorded in the lower reach in June when salinities were low. The shrimps were almost always absent in the upper reach. Juveniles were found mostly in the lower and middle reaches, whereas adults were distributed in all three reaches. Regression analyses showed no statistically significant relationship for either abundance or biomass of the shrimps with temperature, salinity and dissolved oxygen (p > 0.05). The relationship between shrimp abundance and biomass and vegetation cover was positive and statistically significant (R2 = 0.109 and 0.185, respectively; p < 0.05). Vegetation cover plays an important role in determining the presence, distribution and abundance or biomass of P. peringueyi in this estuary.
- Full Text: false
- Date Issued: 2014
- Authors: Nyalungu, Nonhlanhla P , Hodgson, Alan N , Froneman, P William , Dopolo, M , Masubelele, M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68106 , vital:29200 , https://doi.org/10.2989/16085914.2014.960792
- Description: Publisher version , Biological and physico-chemical factors affecting abundance and biomass of shrimp Palaemon peringueyi were investigated in 2010–2011 in the lower, middle and upper reaches of the freshwater-deprived permanently open Kariega Estuary. Shrimp abundance and biomass ranged from 0 to 88 ind. m−2 and 0 to 4.4 g wwt m−2, respectively. Shrimps were most abundant in the lower reach, and highest abundances and biomasses were recorded in the lower reach in June when salinities were low. The shrimps were almost always absent in the upper reach. Juveniles were found mostly in the lower and middle reaches, whereas adults were distributed in all three reaches. Regression analyses showed no statistically significant relationship for either abundance or biomass of the shrimps with temperature, salinity and dissolved oxygen (p > 0.05). The relationship between shrimp abundance and biomass and vegetation cover was positive and statistically significant (R2 = 0.109 and 0.185, respectively; p < 0.05). Vegetation cover plays an important role in determining the presence, distribution and abundance or biomass of P. peringueyi in this estuary.
- Full Text: false
- Date Issued: 2014
Temporal shifts in the fatty acid profiles of rocky intertidal invertebrates
- Richoux, Nicole B, Ndhlovu, Rachel T
- Authors: Richoux, Nicole B , Ndhlovu, Rachel T
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457336 , vital:75626 , xlink:href="https://doi.org/10.1007/s00227-014-2481-z"
- Description: Fatty acid profiles were determined in rocky intertidal suspension-feeders (mussels and polychaetes) and grazers (limpets and sea urchins) on a monthly basis over 1 year to assess potential dietary overlap between consumers occupying the same trophic guild, and any temporal shifts in diets. Both reproductive and non-reproductive tissues were assessed in an attempt to separate influences of food quality with those of life cycle. Relative variability in fatty acids over time could not be predicted from the feeding guild occupied by a consumer, and influential factors of the temporal shifts included both dietary and reproductive dynamics (even in muscle tissues). Species in the same trophic guild occupied separate trophic niches throughout the year, hence minimising competitive interactions regarding food acquisition. Based on overall variation in fatty acid profiles of muscle tissues, the suspension-feeders Perna perna and Gunnarea gaimardi and the grazing limpet Cymbula oculus occupied narrower feeding niches relative to the grazing sea urchin Parechinus angulosus. Our results provide compelling evidence for potentially large changes in the lipid composition of intertidal invertebrate populations over relatively small temporal scales (i.e. month to month), and these have important implications for short-term field collections intended for assessing invertebrate diets.
- Full Text:
- Date Issued: 2014
- Authors: Richoux, Nicole B , Ndhlovu, Rachel T
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457336 , vital:75626 , xlink:href="https://doi.org/10.1007/s00227-014-2481-z"
- Description: Fatty acid profiles were determined in rocky intertidal suspension-feeders (mussels and polychaetes) and grazers (limpets and sea urchins) on a monthly basis over 1 year to assess potential dietary overlap between consumers occupying the same trophic guild, and any temporal shifts in diets. Both reproductive and non-reproductive tissues were assessed in an attempt to separate influences of food quality with those of life cycle. Relative variability in fatty acids over time could not be predicted from the feeding guild occupied by a consumer, and influential factors of the temporal shifts included both dietary and reproductive dynamics (even in muscle tissues). Species in the same trophic guild occupied separate trophic niches throughout the year, hence minimising competitive interactions regarding food acquisition. Based on overall variation in fatty acid profiles of muscle tissues, the suspension-feeders Perna perna and Gunnarea gaimardi and the grazing limpet Cymbula oculus occupied narrower feeding niches relative to the grazing sea urchin Parechinus angulosus. Our results provide compelling evidence for potentially large changes in the lipid composition of intertidal invertebrate populations over relatively small temporal scales (i.e. month to month), and these have important implications for short-term field collections intended for assessing invertebrate diets.
- Full Text:
- Date Issued: 2014
Temporal variability in the fatty acid composition of suspension-feeders and grazers on a South African rocky shore
- Authors: Ndhlovu, Rachel Tintswalo
- Date: 2014
- Subjects: Lipids , Suspension feeders -- South Africa , Intertidal organisms -- South Africa , Marine invertebrates -- South Africa , Marine invertebrates -- Food -- South Africa , Marine invertebrates -- Life cycles -- South Africa , Marine invertebrates -- Reproduction , Benthos -- South Africa , Intertidal ecology -- South Africa , Fatty acids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5949 , http://hdl.handle.net/10962/d1020879
- Description: Numerous ecological studies have used lipids to determine trophic pathways in aquatic systems, as fatty acid profiles provide time-integrated information on an organism’s assimilated diet. Many of these studies have, however, been based on sample collections with a limited temporal scale. The trophic ecology of pelagic systems has been studied intensively using fatty acid analyses, but very little work has been directed toward benthic communities, with the intertidal being especially neglected. The investigation of trophic pathways within rocky shore communities will help us to better understand system responses to environmental changes. The determination of long term temporal variation of the food web within a community could reveal the type, magnitude, duration and frequency of highly seasonal productivity. Changes in fatty acid profiles through time in primary consumers of intertidal rocky shores are poorly understood, but represent an important step towards a more comprehensive understanding of rocky shore food webs, compared with those derived from snapshot or short-term studies. The aim of this thesis was to clarify the temporal variability in the diets of rocky shore intertidal suspension-feeders (the brown mussels Perna perna and the Cape reef worm, Gunnarea gaimardi) and grazers (the Cape sea urchin Parencinus angulosus and the Goat-eye limpet, Cymbulus oculus) on the south east coast of South Africa using fatty acid profiles, and to investigate the effects of life style (e.g. feeding mode) and life cycle on temporal variations in tissue fatty acid profiles. I had three hypotheses: firstly, that suspension-feeders experience high levels of variability in their diets through time because water quality has the potential to change quickly and drastically, whereas grazers experience less variability in their diets over time since their food sources are more constant. Secondly, the reproductive cycles of the suspension-feeder P. perna and the grazer P. angulosus affect the fatty acid composition of their gonads, with temporal variations in lipid composition reflecting changes in reproduction investment. Thirdly, the total amount of energetic reserves available for reproduction are different for each gender (females allocate more energy to egg production than males allocate to gamete production). To address these aims, fatty acid profiles of suspension-feeders and grazers were investigated over a period of twelve months (from July 2010 to June 2011) at a single site on the south east coast of South Africa. The results showed high variability in the fatty acid composition of both the suspension-feeders strongly related with changes in their food source (suspended particulate material). Furthermore, similar temporal changes in fatty acid profiles of the two suspension-feeders were observed over time, reflecting their common diet and life style. There were some inter-specific differences in the suspension-feeders, likely originating from differences in their particle capturing mechanisms. Grazers showed less variability through time compared with the suspension-feeders, with the limpets being more consistent than the sea urchins. The temporal variability in the sea urchin diets may have resulted from the highly diverse and heterogeneous food sources available to them, whereas limpets may be more selective and have a limited range of diet items. Differences between the two grazer species may have arose from differences in their feeding strategies and intertidal zonation. The fatty acid compositions of gonad tissues in both P. perna and P. angulosus showed temporal variability strongly related to reproductive cycle. Differences in the fatty acid values between females and males were apparent, with females richer in total and polyunsaturated fatty acids than males. Spawning and gametogenesis influenced the variability of fatty acids through time in both species, suggesting the importance of considering the reproductive cycle when studying lipids in rocky shore species. Little evidence of lipid transfer between muscles and gonads was seen, suggesting the importance of direct lipid storage into the reproductive tissues. The influence of diet and life history of intertidal consumers on the temporal variability of their fatty acid compositions is important to understand, as it provides us with a better understanding of the functioning of rocky shore systems. There is an enormous potential for future research in this field of study.
- Full Text:
- Date Issued: 2014
- Authors: Ndhlovu, Rachel Tintswalo
- Date: 2014
- Subjects: Lipids , Suspension feeders -- South Africa , Intertidal organisms -- South Africa , Marine invertebrates -- South Africa , Marine invertebrates -- Food -- South Africa , Marine invertebrates -- Life cycles -- South Africa , Marine invertebrates -- Reproduction , Benthos -- South Africa , Intertidal ecology -- South Africa , Fatty acids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5949 , http://hdl.handle.net/10962/d1020879
- Description: Numerous ecological studies have used lipids to determine trophic pathways in aquatic systems, as fatty acid profiles provide time-integrated information on an organism’s assimilated diet. Many of these studies have, however, been based on sample collections with a limited temporal scale. The trophic ecology of pelagic systems has been studied intensively using fatty acid analyses, but very little work has been directed toward benthic communities, with the intertidal being especially neglected. The investigation of trophic pathways within rocky shore communities will help us to better understand system responses to environmental changes. The determination of long term temporal variation of the food web within a community could reveal the type, magnitude, duration and frequency of highly seasonal productivity. Changes in fatty acid profiles through time in primary consumers of intertidal rocky shores are poorly understood, but represent an important step towards a more comprehensive understanding of rocky shore food webs, compared with those derived from snapshot or short-term studies. The aim of this thesis was to clarify the temporal variability in the diets of rocky shore intertidal suspension-feeders (the brown mussels Perna perna and the Cape reef worm, Gunnarea gaimardi) and grazers (the Cape sea urchin Parencinus angulosus and the Goat-eye limpet, Cymbulus oculus) on the south east coast of South Africa using fatty acid profiles, and to investigate the effects of life style (e.g. feeding mode) and life cycle on temporal variations in tissue fatty acid profiles. I had three hypotheses: firstly, that suspension-feeders experience high levels of variability in their diets through time because water quality has the potential to change quickly and drastically, whereas grazers experience less variability in their diets over time since their food sources are more constant. Secondly, the reproductive cycles of the suspension-feeder P. perna and the grazer P. angulosus affect the fatty acid composition of their gonads, with temporal variations in lipid composition reflecting changes in reproduction investment. Thirdly, the total amount of energetic reserves available for reproduction are different for each gender (females allocate more energy to egg production than males allocate to gamete production). To address these aims, fatty acid profiles of suspension-feeders and grazers were investigated over a period of twelve months (from July 2010 to June 2011) at a single site on the south east coast of South Africa. The results showed high variability in the fatty acid composition of both the suspension-feeders strongly related with changes in their food source (suspended particulate material). Furthermore, similar temporal changes in fatty acid profiles of the two suspension-feeders were observed over time, reflecting their common diet and life style. There were some inter-specific differences in the suspension-feeders, likely originating from differences in their particle capturing mechanisms. Grazers showed less variability through time compared with the suspension-feeders, with the limpets being more consistent than the sea urchins. The temporal variability in the sea urchin diets may have resulted from the highly diverse and heterogeneous food sources available to them, whereas limpets may be more selective and have a limited range of diet items. Differences between the two grazer species may have arose from differences in their feeding strategies and intertidal zonation. The fatty acid compositions of gonad tissues in both P. perna and P. angulosus showed temporal variability strongly related to reproductive cycle. Differences in the fatty acid values between females and males were apparent, with females richer in total and polyunsaturated fatty acids than males. Spawning and gametogenesis influenced the variability of fatty acids through time in both species, suggesting the importance of considering the reproductive cycle when studying lipids in rocky shore species. Little evidence of lipid transfer between muscles and gonads was seen, suggesting the importance of direct lipid storage into the reproductive tissues. The influence of diet and life history of intertidal consumers on the temporal variability of their fatty acid compositions is important to understand, as it provides us with a better understanding of the functioning of rocky shore systems. There is an enormous potential for future research in this field of study.
- Full Text:
- Date Issued: 2014