Phenolic compounds in water and the implications for rapid detection of indicator micro-organisms using ß-D-Galactosidase and ß-D-Glucuronidase
- Authors: Abboo, Sagaran
- Date: 2009
- Subjects: Water -- Purification -- Biological treatment , Pollutants -- Biodegradation , Phenol , Organic water pollutants , Water quality biological assessment , Water -- Pollution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3978 , http://hdl.handle.net/10962/d1004037 , Water -- Purification -- Biological treatment , Pollutants -- Biodegradation , Phenol , Organic water pollutants , Water quality biological assessment , Water -- Pollution
- Description: Faecal contamination in water is detected using appropriate microbial models such as total coliforms, faecal coliforms and E. coli. Βeta-D-Galactosidase (β-GAL) and Beta-D-glucuronidase (β-GUD) are two marker enzymes that are used to test for the presence of total coliforms and E. coli in water samples, respectively. Various assay methods have been developed using chromogenic and fluorogenic substrates. In this study, the chromogenic substrates chlorophenol red β-D-galactopyranoside (CPRG) for β-GAL and p-nitrophenyl-β-D-galactopyranoside (PNPG) for β-GUD were used. Potential problems associated with this approach include interference from other organisms present in the environment (e.g. plants, algae and other bacteria), as well as the presence of certain chemicals, such as phenolic compounds in water. Phenolic compounds are present in the aquatic environment due to their extensive industrial applications. The USA Enviromental Protection Agency (EPA) lists 11 Priority Pollutant Phenols (PPP) due to their high level of toxicity. This study investigated the interfering effects of the eleven PPP found in water on the enzyme activities of both the β-GAL and β-GUD enzyme assays. The presence of these PPP in the β-GAL and β-GUD enzyme assays showed that over and underestimation of activity may occur due to inhibition or activation of these enzymes. Three types of inhibition to enzyme activities were identified from double reciprocal Lineweaver-Burk plots. The inhibition constants (Ki) were determined for all inhibitory phenolic compounds from appropriate secondary plots. Furthermore, this study presented a validated reverse phase high performance liquid chromatography (RP-HPLC) method, developed for the simultaneous detection, separation and determination of all eleven phenolic compounds found in the environment. This method demonstrated good linearity, reproducibility, accuracy and sensitivity. Environmental water samples were collected from rivers, streams, industrial sites and wastewater treatment plant effluent. These samples were extracted and concentrated using a solid phase extraction (SPE) procedure prior to analysis employing the newly developed HPLC method in this study. Seasonal variations on the presence of the PPP in the environment were observed at certain collection sites. The concentrations found were between 0.033 μg/ml for 2,4-dinitrophenol in a running stream to 0.890 mg/ml for pentachlorophenol from an tannery industrial site. These concentrations of phenolic compounds found in these environments were able to interfere with the β-GAL and β-GUD enzyme assays.
- Full Text:
- Date Issued: 2009
- Authors: Abboo, Sagaran
- Date: 2009
- Subjects: Water -- Purification -- Biological treatment , Pollutants -- Biodegradation , Phenol , Organic water pollutants , Water quality biological assessment , Water -- Pollution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3978 , http://hdl.handle.net/10962/d1004037 , Water -- Purification -- Biological treatment , Pollutants -- Biodegradation , Phenol , Organic water pollutants , Water quality biological assessment , Water -- Pollution
- Description: Faecal contamination in water is detected using appropriate microbial models such as total coliforms, faecal coliforms and E. coli. Βeta-D-Galactosidase (β-GAL) and Beta-D-glucuronidase (β-GUD) are two marker enzymes that are used to test for the presence of total coliforms and E. coli in water samples, respectively. Various assay methods have been developed using chromogenic and fluorogenic substrates. In this study, the chromogenic substrates chlorophenol red β-D-galactopyranoside (CPRG) for β-GAL and p-nitrophenyl-β-D-galactopyranoside (PNPG) for β-GUD were used. Potential problems associated with this approach include interference from other organisms present in the environment (e.g. plants, algae and other bacteria), as well as the presence of certain chemicals, such as phenolic compounds in water. Phenolic compounds are present in the aquatic environment due to their extensive industrial applications. The USA Enviromental Protection Agency (EPA) lists 11 Priority Pollutant Phenols (PPP) due to their high level of toxicity. This study investigated the interfering effects of the eleven PPP found in water on the enzyme activities of both the β-GAL and β-GUD enzyme assays. The presence of these PPP in the β-GAL and β-GUD enzyme assays showed that over and underestimation of activity may occur due to inhibition or activation of these enzymes. Three types of inhibition to enzyme activities were identified from double reciprocal Lineweaver-Burk plots. The inhibition constants (Ki) were determined for all inhibitory phenolic compounds from appropriate secondary plots. Furthermore, this study presented a validated reverse phase high performance liquid chromatography (RP-HPLC) method, developed for the simultaneous detection, separation and determination of all eleven phenolic compounds found in the environment. This method demonstrated good linearity, reproducibility, accuracy and sensitivity. Environmental water samples were collected from rivers, streams, industrial sites and wastewater treatment plant effluent. These samples were extracted and concentrated using a solid phase extraction (SPE) procedure prior to analysis employing the newly developed HPLC method in this study. Seasonal variations on the presence of the PPP in the environment were observed at certain collection sites. The concentrations found were between 0.033 μg/ml for 2,4-dinitrophenol in a running stream to 0.890 mg/ml for pentachlorophenol from an tannery industrial site. These concentrations of phenolic compounds found in these environments were able to interfere with the β-GAL and β-GUD enzyme assays.
- Full Text:
- Date Issued: 2009
Effect of processing on the efficacy and safety of Solanum Aculeastrum Dunal berries
- Authors: Aboyade, Oluwaseyi Mayode
- Date: 2009
- Subjects: Medicinal plants -- South Africa -- Eastern Cape , Plant extracts , Drugs -- Effectiveness , Berries , Solanum , Solanum Aculeastrum -- Effectiveness
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11302 , http://hdl.handle.net/10353/d1001051 , Medicinal plants -- South Africa -- Eastern Cape , Plant extracts , Drugs -- Effectiveness , Berries , Solanum , Solanum Aculeastrum -- Effectiveness
- Description: General Abstract There has been a steady increase in the use of medicinal plants in the last two decades in both developed and developing countries for prevention, management and treatment of diseases. This increase has been due to reasons such as ease of access, better cultural acceptability and compatibility, cost effectiveness and also the bid to “go natural”. Unfortunately, the notion that herbal medicines are relatively safe because they are natural has led to serious and potentially fatal consequences in phytotherapy. The lack of rigorous research to prove the effectiveness and safety of many medicinal plants is of great concern to the health care system. This thesis therefore addresses not just the efficacy, but also the safety of the extracts of the berry of Solanum aculeastrum - a medicinal plant used, among other things, for the treatment of breast cancer in the Eastern Cape Province of South Africa. Particular attention was paid to the possible effect of different processing methods of the berry extracts on inflammation, cytotoxicity, and toxicity. In studying the comparative effects of various processing methods, four different preparations of the extracts were investigated. These include fresh, dried, boiled fresh, and boiled dried berries. While the effect of processing on the anti-inflammatory properties of the extracts was not dose dependent, the percentage reduction in inflammation was highly significant and more prominent in both concentrations of the boiled fresh berries than the reference drug, indomethacin. Furthermore, the four extracts varied in their ability to act either centrally or peripherally in their effect on pain. Assessment of the analgesic response using the formalin test showed that, at both concentrations tested, none of the extracts inhibited the first phase of the formalin test. Furthermore, it was observed that boiling had differing results on the activity of the iii fresh and dried extracts. While boiling of the dried berries reduced pain in the rats, the opposite trend was observed with the boiled fresh berries. Results of the influence of processing of the berries on cytotoxicity indicated that the extracts are potent inhibitors of human breast, cervical and colonic carcinoma cells and the non-cancerous cells (both the actively dividing and confluent Chang liver cells). Although, in terms of relative potency, the fresh berries appeared to be the most active of the extracts, processing of the berries caused an increase in apoptotic cells and a subsequent decrease in the necrotic cells. The effect of processing on the safety of the berry of S. aculeastrum on the rats fed for 28 days was also investigated. The various doses (1, 10 and 25 mg/kg body weight) of all the four extracts did not alter the activity and the weight of the animals throughout the period of treatment. A reduction in organ to body weight ratio of the heart, kidney, liver and spleen was observed in all the extracts. Regarding the haematological parameters, different patterns of effect were observed between the extracts and within the treated doses. The observed alterations in the biochemical parameters by the various extract of Solanum aculeastrum berries at all the doses may have consequential effects on the normal functioning of these organs. In conclusion, this study has shown that there is some justification for the traditional use of the berries of Solanum aculeastrum in the treatment of inflammation related ailments and cancer. However, the medicinal use of the plant also poses considerable health risks. Investigation conducted into the plant’s safety revealed that the berry extracts were nephrotoxic, hepatotoxic, haematotoxic and at higher doses, fatal. Another concern with regard to the plant’s safety is the non-selectivity of its extracts in the inhibition of carcinoma, actively dividing and un-dividing cells. Assessment of the effect of the processing on the berry’s efficacy and safety as herbal iv remedy produced mixed results. On the one hand, processing seemed to improve the extract’s anti-inflammatory and analgesic activity, while reducing its cytotoxic potential. On the other hand, a reduction in the toxicity was observed on the processed extracts compared to the fresh ones. This may be an indication that processing has an overall beneficial effect on the medicinal properties of the plant and should thus be considered as a method of making the berries of Solanum aculeastrum safer for use as a herbal remedy.
- Full Text:
- Date Issued: 2009
- Authors: Aboyade, Oluwaseyi Mayode
- Date: 2009
- Subjects: Medicinal plants -- South Africa -- Eastern Cape , Plant extracts , Drugs -- Effectiveness , Berries , Solanum , Solanum Aculeastrum -- Effectiveness
- Language: English
- Type: Thesis , Doctoral , PhD (Botany)
- Identifier: vital:11302 , http://hdl.handle.net/10353/d1001051 , Medicinal plants -- South Africa -- Eastern Cape , Plant extracts , Drugs -- Effectiveness , Berries , Solanum , Solanum Aculeastrum -- Effectiveness
- Description: General Abstract There has been a steady increase in the use of medicinal plants in the last two decades in both developed and developing countries for prevention, management and treatment of diseases. This increase has been due to reasons such as ease of access, better cultural acceptability and compatibility, cost effectiveness and also the bid to “go natural”. Unfortunately, the notion that herbal medicines are relatively safe because they are natural has led to serious and potentially fatal consequences in phytotherapy. The lack of rigorous research to prove the effectiveness and safety of many medicinal plants is of great concern to the health care system. This thesis therefore addresses not just the efficacy, but also the safety of the extracts of the berry of Solanum aculeastrum - a medicinal plant used, among other things, for the treatment of breast cancer in the Eastern Cape Province of South Africa. Particular attention was paid to the possible effect of different processing methods of the berry extracts on inflammation, cytotoxicity, and toxicity. In studying the comparative effects of various processing methods, four different preparations of the extracts were investigated. These include fresh, dried, boiled fresh, and boiled dried berries. While the effect of processing on the anti-inflammatory properties of the extracts was not dose dependent, the percentage reduction in inflammation was highly significant and more prominent in both concentrations of the boiled fresh berries than the reference drug, indomethacin. Furthermore, the four extracts varied in their ability to act either centrally or peripherally in their effect on pain. Assessment of the analgesic response using the formalin test showed that, at both concentrations tested, none of the extracts inhibited the first phase of the formalin test. Furthermore, it was observed that boiling had differing results on the activity of the iii fresh and dried extracts. While boiling of the dried berries reduced pain in the rats, the opposite trend was observed with the boiled fresh berries. Results of the influence of processing of the berries on cytotoxicity indicated that the extracts are potent inhibitors of human breast, cervical and colonic carcinoma cells and the non-cancerous cells (both the actively dividing and confluent Chang liver cells). Although, in terms of relative potency, the fresh berries appeared to be the most active of the extracts, processing of the berries caused an increase in apoptotic cells and a subsequent decrease in the necrotic cells. The effect of processing on the safety of the berry of S. aculeastrum on the rats fed for 28 days was also investigated. The various doses (1, 10 and 25 mg/kg body weight) of all the four extracts did not alter the activity and the weight of the animals throughout the period of treatment. A reduction in organ to body weight ratio of the heart, kidney, liver and spleen was observed in all the extracts. Regarding the haematological parameters, different patterns of effect were observed between the extracts and within the treated doses. The observed alterations in the biochemical parameters by the various extract of Solanum aculeastrum berries at all the doses may have consequential effects on the normal functioning of these organs. In conclusion, this study has shown that there is some justification for the traditional use of the berries of Solanum aculeastrum in the treatment of inflammation related ailments and cancer. However, the medicinal use of the plant also poses considerable health risks. Investigation conducted into the plant’s safety revealed that the berry extracts were nephrotoxic, hepatotoxic, haematotoxic and at higher doses, fatal. Another concern with regard to the plant’s safety is the non-selectivity of its extracts in the inhibition of carcinoma, actively dividing and un-dividing cells. Assessment of the effect of the processing on the berry’s efficacy and safety as herbal iv remedy produced mixed results. On the one hand, processing seemed to improve the extract’s anti-inflammatory and analgesic activity, while reducing its cytotoxic potential. On the other hand, a reduction in the toxicity was observed on the processed extracts compared to the fresh ones. This may be an indication that processing has an overall beneficial effect on the medicinal properties of the plant and should thus be considered as a method of making the berries of Solanum aculeastrum safer for use as a herbal remedy.
- Full Text:
- Date Issued: 2009
The coordination chemistry of Rhenium(V) with multidentate no-donor ligands
- Authors: Abrahams, Abubak'r
- Date: 2009
- Subjects: Rhenium , Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10370 , http://hdl.handle.net/10948/912 , Rhenium , Ligands
- Description: The neutral distorted octahedral complexes [ReOCl(L)] {H2L = N,N-bis(2- hydroxybenzyl)-2-(2-aminoethyl)dimethylamine (H2had), N,N-bis(2-hydroxybenzyl) aminomethylpyridine (H2hap); N,N-bis(2-hydroxybenzyl)-2-(2-aminoethyl)pyridine (H2hae)} were prepared by the reaction of trans-[ReOCl3(PPh3)2] with a twofold molar excess of H2L in ethanol. The X-ray structure determinations of [ReOCl(had)] and [ReOCl(hap)] were performed, and in both complexes the chloride is coordinated trans to the tripodal tertiary amino nitrogen, with a phenolate oxygen trans to the oxo oxygen. Treatment of trans-[ReO2(py)4]I with two equivalents and one equivalent each of H2had in acetone afforded the iodide salts of the oxypyridinium-ammonium zwitterions N1-(2-hydroxybenzyl)-N2,N2- dimethyl-N1-((2-oxypyridinium)-1-methyl)ethane-1,2-diamine [Hhpd]+ and N2,N2- dimethyl-N1-bis((2-oxypyridinium)-1-methyl)ethane-1,2-diamine [dod]+ respectively. In [Hhpd]I, one of the 2-hydroxyphenyl groups of H2had is substituted by an oxypyridinium group, and in [dod]I, both 2-hydroxyphenyl groups are converted. The X-ray crystal structure determination of the starting material H2had, [Hhpd]I and [dod]I reveals trigonal pyramidal geometries around the central amino nitrogen. The complex salt [ReO(bsa)]PF6 (H2bsa=bis(N-methylsalicylicylideneiminopropyl) amine) was prepared from the reaction of cis-[ReO2I(PPh3)2] with H2bsa in toluene. The dianionic pentadentate ligand bsa is coordinated to the ReO3+ moiety via one secondary amino and two imino nitrogens, and two anionic phenolate oxygens. The complex was characterized by spectroscopy and analytical data, and the structure has been determined by single-crystal X-ray diffraction analysis. The complex exhibits a distorted octahedral geometry around the central rhenium(V) ion, with the basal plane being defined by a phenolate oxygen, two imino nitrogens and the secondary amino. ix A. Abrahams Nelson Mandela Metropolitan University The reaction of a two-fold molar excess of the potentially NN-donor ligand 2,2’- dipyridylamine (dpa) with trans-[ReO(OEt)Cl2(PPh3)2] in ethanol led to the isolation of [ReOCl2(OEt)(dpa)]. The X-ray crystal structure shows that the NN-chelated dpa is coordinated in the equatorial plane cis to the oxo and ethoxo groups, which are in trans positions relative to each other. The treatment of trans- [ReOCl3(PPh3)2] with a tenfold molar excess of dpa in ethanol at the refluxing temperature yielded the trans-dioxo complex [ReO2(dpa)2]Cl, but with a twofold molar excess only (μ-O)[{ReOCl2(dpa)}2] was isolated. Repeating the latter reaction with (n-Bu4N)[ReOCl4] as starting material in ethanol at room temperature a dark green product, also with the formulation (μ-O)[{ReOCl2(dpa)}2], was isolated. The reaction of equimolar quantities of bis(pyridin-2-yl)methyl)amine (HBPA) with (n-Bu4N)[ReOCl4] in acetone at room temperature led to the isolation of the sixcoordinate rhenium(V) complex [ReOCl(H2O)(BPA)]Cl. IR, NMR and X-ray crystallographic results indicate that BPA is coordinated as a tridentate uninegative chelate, with deprotonation of the amine nitrogen. The water molecule is coordinated trans to the oxo group, with the Re=O and Re-OH2 bond distances equal to 1.663(9) and 2.21(1) Å respectively. Complexes of the general formula [ReOX2{(C5H4N)CH(O)CH2(C5H4N)}] (X = Cl, I) were prepared by the reactions of trans-[ReOCl3(PPh3)2] and trans- [ReOI2(OEt)(PPh3)2] with cis-1,2-di-(2-pyridyl)ethylene (DPE) in ethanol and benzene in air. Experimental evidence shows that the coordinated DPE ligand has undergone addition of water at the ethylenic carbons, and that the (C5H4N)CH(O)CH2(C5H4N) moiety acts as a uninegative tridentate NON-donor ligand. The X-ray crystal structures of both complexes show a distorted octahedral geometry around the rhenium(V) centre. The treatment of trans-[ReOCl3(PPh3)2] with H2dbd in a 2:1 molar ratio in acetonitrile led to the isolation of the ligand-bridged dimer (μ-dbd)[ReOCl2(PPh3)]2. The X-ray crystal structure of the complex reveals a dinuclear structure in which two rhenium(V) ions are bridged by the dbd ligand. Each rhenium ion is in a x A. Abrahams Nelson Mandela Metropolitan University distorted octahedral geometry. The basal plane is defined by a phosphorus atom of the PPh3 group, two chlorides cis to each other, and a pyridyl nitrogen atom of dbd. The oxo group and alcoholate oxygen of dbd lie in trans axial positions. The complexes cis-[ReOX2(msa)(PPh3)] (X = Cl, Br, I) were prepared from trans- [ReOCl3(PPh3)2], trans-[ReOBr3(PPh3)2] or trans-[ReOI2(OEt)(PPh3)2] with 2-(1- iminoethyl)phenol (Hmsa) in acetonitrile. An X-ray crystallographic study shows that the bonding distances and angles in the comlexes are nearly identical, and that the two halides in each complex are coordinated cis to each other in the equatorial plane cis to the oxo group. The oxo-bridged dinuclear rhenium(V) complex [(μ-O){ReOCl(amp)}2] was prepared by the reaction of trans-[ReOCl3(PPh3)2] and 6-amino-3-methyl-1-phenyl- 4-azahept-2-ene-1-one (Hamp) in acetone. The characterization of the complex by elemental analysis, infrared and 1H NMR spectroscopy and X-ray crystallography shows that amp is coordinated as a monoanionic NNO-donor chelate as an amino-amido ketone. However, the reaction of the similar ligand 7- amino-4,7-dimethyl-5-aza-3-octen-2-one (Hada) with [Re(CO)5Br] produced the product fac-[Re(CO)3Br(Hada)], with Hada coordinated as a neutral NN-donor amino-imino-ketone.
- Full Text:
- Date Issued: 2009
- Authors: Abrahams, Abubak'r
- Date: 2009
- Subjects: Rhenium , Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10370 , http://hdl.handle.net/10948/912 , Rhenium , Ligands
- Description: The neutral distorted octahedral complexes [ReOCl(L)] {H2L = N,N-bis(2- hydroxybenzyl)-2-(2-aminoethyl)dimethylamine (H2had), N,N-bis(2-hydroxybenzyl) aminomethylpyridine (H2hap); N,N-bis(2-hydroxybenzyl)-2-(2-aminoethyl)pyridine (H2hae)} were prepared by the reaction of trans-[ReOCl3(PPh3)2] with a twofold molar excess of H2L in ethanol. The X-ray structure determinations of [ReOCl(had)] and [ReOCl(hap)] were performed, and in both complexes the chloride is coordinated trans to the tripodal tertiary amino nitrogen, with a phenolate oxygen trans to the oxo oxygen. Treatment of trans-[ReO2(py)4]I with two equivalents and one equivalent each of H2had in acetone afforded the iodide salts of the oxypyridinium-ammonium zwitterions N1-(2-hydroxybenzyl)-N2,N2- dimethyl-N1-((2-oxypyridinium)-1-methyl)ethane-1,2-diamine [Hhpd]+ and N2,N2- dimethyl-N1-bis((2-oxypyridinium)-1-methyl)ethane-1,2-diamine [dod]+ respectively. In [Hhpd]I, one of the 2-hydroxyphenyl groups of H2had is substituted by an oxypyridinium group, and in [dod]I, both 2-hydroxyphenyl groups are converted. The X-ray crystal structure determination of the starting material H2had, [Hhpd]I and [dod]I reveals trigonal pyramidal geometries around the central amino nitrogen. The complex salt [ReO(bsa)]PF6 (H2bsa=bis(N-methylsalicylicylideneiminopropyl) amine) was prepared from the reaction of cis-[ReO2I(PPh3)2] with H2bsa in toluene. The dianionic pentadentate ligand bsa is coordinated to the ReO3+ moiety via one secondary amino and two imino nitrogens, and two anionic phenolate oxygens. The complex was characterized by spectroscopy and analytical data, and the structure has been determined by single-crystal X-ray diffraction analysis. The complex exhibits a distorted octahedral geometry around the central rhenium(V) ion, with the basal plane being defined by a phenolate oxygen, two imino nitrogens and the secondary amino. ix A. Abrahams Nelson Mandela Metropolitan University The reaction of a two-fold molar excess of the potentially NN-donor ligand 2,2’- dipyridylamine (dpa) with trans-[ReO(OEt)Cl2(PPh3)2] in ethanol led to the isolation of [ReOCl2(OEt)(dpa)]. The X-ray crystal structure shows that the NN-chelated dpa is coordinated in the equatorial plane cis to the oxo and ethoxo groups, which are in trans positions relative to each other. The treatment of trans- [ReOCl3(PPh3)2] with a tenfold molar excess of dpa in ethanol at the refluxing temperature yielded the trans-dioxo complex [ReO2(dpa)2]Cl, but with a twofold molar excess only (μ-O)[{ReOCl2(dpa)}2] was isolated. Repeating the latter reaction with (n-Bu4N)[ReOCl4] as starting material in ethanol at room temperature a dark green product, also with the formulation (μ-O)[{ReOCl2(dpa)}2], was isolated. The reaction of equimolar quantities of bis(pyridin-2-yl)methyl)amine (HBPA) with (n-Bu4N)[ReOCl4] in acetone at room temperature led to the isolation of the sixcoordinate rhenium(V) complex [ReOCl(H2O)(BPA)]Cl. IR, NMR and X-ray crystallographic results indicate that BPA is coordinated as a tridentate uninegative chelate, with deprotonation of the amine nitrogen. The water molecule is coordinated trans to the oxo group, with the Re=O and Re-OH2 bond distances equal to 1.663(9) and 2.21(1) Å respectively. Complexes of the general formula [ReOX2{(C5H4N)CH(O)CH2(C5H4N)}] (X = Cl, I) were prepared by the reactions of trans-[ReOCl3(PPh3)2] and trans- [ReOI2(OEt)(PPh3)2] with cis-1,2-di-(2-pyridyl)ethylene (DPE) in ethanol and benzene in air. Experimental evidence shows that the coordinated DPE ligand has undergone addition of water at the ethylenic carbons, and that the (C5H4N)CH(O)CH2(C5H4N) moiety acts as a uninegative tridentate NON-donor ligand. The X-ray crystal structures of both complexes show a distorted octahedral geometry around the rhenium(V) centre. The treatment of trans-[ReOCl3(PPh3)2] with H2dbd in a 2:1 molar ratio in acetonitrile led to the isolation of the ligand-bridged dimer (μ-dbd)[ReOCl2(PPh3)]2. The X-ray crystal structure of the complex reveals a dinuclear structure in which two rhenium(V) ions are bridged by the dbd ligand. Each rhenium ion is in a x A. Abrahams Nelson Mandela Metropolitan University distorted octahedral geometry. The basal plane is defined by a phosphorus atom of the PPh3 group, two chlorides cis to each other, and a pyridyl nitrogen atom of dbd. The oxo group and alcoholate oxygen of dbd lie in trans axial positions. The complexes cis-[ReOX2(msa)(PPh3)] (X = Cl, Br, I) were prepared from trans- [ReOCl3(PPh3)2], trans-[ReOBr3(PPh3)2] or trans-[ReOI2(OEt)(PPh3)2] with 2-(1- iminoethyl)phenol (Hmsa) in acetonitrile. An X-ray crystallographic study shows that the bonding distances and angles in the comlexes are nearly identical, and that the two halides in each complex are coordinated cis to each other in the equatorial plane cis to the oxo group. The oxo-bridged dinuclear rhenium(V) complex [(μ-O){ReOCl(amp)}2] was prepared by the reaction of trans-[ReOCl3(PPh3)2] and 6-amino-3-methyl-1-phenyl- 4-azahept-2-ene-1-one (Hamp) in acetone. The characterization of the complex by elemental analysis, infrared and 1H NMR spectroscopy and X-ray crystallography shows that amp is coordinated as a monoanionic NNO-donor chelate as an amino-amido ketone. However, the reaction of the similar ligand 7- amino-4,7-dimethyl-5-aza-3-octen-2-one (Hada) with [Re(CO)5Br] produced the product fac-[Re(CO)3Br(Hada)], with Hada coordinated as a neutral NN-donor amino-imino-ketone.
- Full Text:
- Date Issued: 2009
The phenomenolgoical experience of posttraumatic growth in the context of a traumatic bereavement
- Authors: Acheson, Kerry
- Date: 2009 , 2013-07-15
- Subjects: Post-traumatic stress disorder -- Case studies Bereavement -- Psychological aspects Death -- Psychological aspects Phenomenological psychology Grief
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3102 , http://hdl.handle.net/10962/d1004456
- Description: The present study involves an exploration of the phenomenological expenence of posttraumatic growth in the context of a traumatic bereavement. An idiographic case study of a student who had witnessed her mother's death twelve years previously was conducted. Semi-structured interviews elicited data which was analysed using interpretative phenomenological analysis (IP A). Posttraumatic growth was found to have developed with regards to self-perception, relationships, and also in a broader spiritual and existential domain. The findings of this study shed light on the extant posttraumatic growth literature. In particular, findings were discussed in relation to the posttraumatic growth model as proposed by Calhoun and Tedeschi (2006). As posttraumatic growth is a relatively young concept, further research is needed in order to understand the meaning of reported growth more fully. While posttraumatic growth has been investigated in the context of bereavement, future research should distinguish more clearly between growth following traumatic and non-traumatic bereavement. Posttraumatic growth has received minimal empirical attention in South Africa, and therefore exploration of this area is suggested in the future. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2009
- Authors: Acheson, Kerry
- Date: 2009 , 2013-07-15
- Subjects: Post-traumatic stress disorder -- Case studies Bereavement -- Psychological aspects Death -- Psychological aspects Phenomenological psychology Grief
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3102 , http://hdl.handle.net/10962/d1004456
- Description: The present study involves an exploration of the phenomenological expenence of posttraumatic growth in the context of a traumatic bereavement. An idiographic case study of a student who had witnessed her mother's death twelve years previously was conducted. Semi-structured interviews elicited data which was analysed using interpretative phenomenological analysis (IP A). Posttraumatic growth was found to have developed with regards to self-perception, relationships, and also in a broader spiritual and existential domain. The findings of this study shed light on the extant posttraumatic growth literature. In particular, findings were discussed in relation to the posttraumatic growth model as proposed by Calhoun and Tedeschi (2006). As posttraumatic growth is a relatively young concept, further research is needed in order to understand the meaning of reported growth more fully. While posttraumatic growth has been investigated in the context of bereavement, future research should distinguish more clearly between growth following traumatic and non-traumatic bereavement. Posttraumatic growth has received minimal empirical attention in South Africa, and therefore exploration of this area is suggested in the future. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2009
An analysis of the reporting on poverty and foreign aid in Sub-Saharan Africa before and during the current global economic crisis, in BBC online (Texts)
- Authors: Achu, Stella
- Date: 2009
- Subjects: Economic assistance -- Africa, Sub-Saharan , Poverty -- Africa, Sub-Saharan , Financial crises , Africa, Sub-Saharan -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8371 , http://hdl.handle.net/10948/1257 , Economic assistance -- Africa, Sub-Saharan , Poverty -- Africa, Sub-Saharan , Financial crises , Africa, Sub-Saharan -- Economic conditions
- Description: Since 1929, the world economy has not encountered any financial crisis as severe as the case of the Great Depression, until 2007 when the fall of stock markets and the collapse of large financial institutions in the United States resulted in a worldwide recession. According to an IMF report, and as a result of the direct impact of the crisis, advanced economies such as those of the United States and Europe are suffering from a systemic banking crisis with economic output expected to contract by over 1 ¾ % in 2009. (Bourdin 2009:2) Although the crisis erupted in the United States, the effects quickly spread to countries worldwide. However, its effects are said to be more devastating for the poorest regions in the world including Sub-Saharan Africa. During the last few years, prior to the crisis, many Sub-Saharan African countries had enjoyed a growth rate of over 5%. This was partly as a result of sound economic policies and increased external support in the form of debt relief and higher inflows from economically powerful countries in the West. However, with the current financial crisis, wealthy nations have been forced to concentrate on sustaining their own economy. As a result, amongst changes like tighter immigration policies, skyrocketing oil prices and food prices, foreign aid is being withdrawn. (ibid 2009:3) According to foreign media reports, donor governments and the G8 are no longer as committed to aid as before the crisis. This research paper examines the evolution of aid to Africa in view of various contexts through a broad historical economic and political economy overview, and finally corroborates these observations with a discourse analysis of a sample of BBC online articles. The research project thus investigates in this last section, the BBC’s representation of poverty and aid in Sub-Saharan Africa before and during the current global economic crisis.
- Full Text:
- Date Issued: 2009
- Authors: Achu, Stella
- Date: 2009
- Subjects: Economic assistance -- Africa, Sub-Saharan , Poverty -- Africa, Sub-Saharan , Financial crises , Africa, Sub-Saharan -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8371 , http://hdl.handle.net/10948/1257 , Economic assistance -- Africa, Sub-Saharan , Poverty -- Africa, Sub-Saharan , Financial crises , Africa, Sub-Saharan -- Economic conditions
- Description: Since 1929, the world economy has not encountered any financial crisis as severe as the case of the Great Depression, until 2007 when the fall of stock markets and the collapse of large financial institutions in the United States resulted in a worldwide recession. According to an IMF report, and as a result of the direct impact of the crisis, advanced economies such as those of the United States and Europe are suffering from a systemic banking crisis with economic output expected to contract by over 1 ¾ % in 2009. (Bourdin 2009:2) Although the crisis erupted in the United States, the effects quickly spread to countries worldwide. However, its effects are said to be more devastating for the poorest regions in the world including Sub-Saharan Africa. During the last few years, prior to the crisis, many Sub-Saharan African countries had enjoyed a growth rate of over 5%. This was partly as a result of sound economic policies and increased external support in the form of debt relief and higher inflows from economically powerful countries in the West. However, with the current financial crisis, wealthy nations have been forced to concentrate on sustaining their own economy. As a result, amongst changes like tighter immigration policies, skyrocketing oil prices and food prices, foreign aid is being withdrawn. (ibid 2009:3) According to foreign media reports, donor governments and the G8 are no longer as committed to aid as before the crisis. This research paper examines the evolution of aid to Africa in view of various contexts through a broad historical economic and political economy overview, and finally corroborates these observations with a discourse analysis of a sample of BBC online articles. The research project thus investigates in this last section, the BBC’s representation of poverty and aid in Sub-Saharan Africa before and during the current global economic crisis.
- Full Text:
- Date Issued: 2009
The experiences of registered nurses' of their work environment in a critical care unit
- Authors: Adams, Bernardene Lucreshia
- Date: 2009
- Subjects: Intensive care nursing -- South Africa , Intensive care units , Nurses -- Job stress -- South Africa
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: vital:10013 , http://hdl.handle.net/10948/1057 , Intensive care nursing -- South Africa , Intensive care units , Nurses -- Job stress -- South Africa
- Description: Critical care nursing is a vital and significant part of health care provision to critically ill patients. It is a specialty area of nursing that requires registered nurses who are highly motivated, knowledgeable and skilled to provide optimal care to critically ill patients. These patients are nursed in a complex environment consisting of specialised equipment (such as ventilators, defibrillators, intravenous pumps, and cardiac monitors) that is not found in any other field of nursing. Collegial support and an adequate registered nurse: patient ratio is vital in critical care units in order to provide optimal quality care to critically ill patients. However, an understaffed work environment, the demands of critical care nursing and other work-related problems, such as conflict with physicians, inadequate remuneration packages and an increased workload can cause serious distress and dissatisfaction amongst registered nurses in this specific environment (Carayon & Gürses, 2005:287). The objectives of this study therefore are to explore and describe the experiences of registered nurses of their work environment in a critical care unit and to make recommendations that will assist registered nurses working in a critical care unit. A qualitative, explorative, descriptive and contextual research design will be utilised. Data will be collected by means of semi-structured interviews and analysed according to the framework provided by Tesch (in Cresswell, 2003:192). Purposive sampling will be used to select a sample of registered nurses working in a critical care environment. Guba’s model (in Krefting, 1991) will be utilised to verify data and to ensure trustworthiness of the study. Ethical considerations will be adhered to throughout the study. Once data has been analysed, recommendations will be made that will assist registered nurses working in a critical care unit.
- Full Text:
- Date Issued: 2009
- Authors: Adams, Bernardene Lucreshia
- Date: 2009
- Subjects: Intensive care nursing -- South Africa , Intensive care units , Nurses -- Job stress -- South Africa
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: vital:10013 , http://hdl.handle.net/10948/1057 , Intensive care nursing -- South Africa , Intensive care units , Nurses -- Job stress -- South Africa
- Description: Critical care nursing is a vital and significant part of health care provision to critically ill patients. It is a specialty area of nursing that requires registered nurses who are highly motivated, knowledgeable and skilled to provide optimal care to critically ill patients. These patients are nursed in a complex environment consisting of specialised equipment (such as ventilators, defibrillators, intravenous pumps, and cardiac monitors) that is not found in any other field of nursing. Collegial support and an adequate registered nurse: patient ratio is vital in critical care units in order to provide optimal quality care to critically ill patients. However, an understaffed work environment, the demands of critical care nursing and other work-related problems, such as conflict with physicians, inadequate remuneration packages and an increased workload can cause serious distress and dissatisfaction amongst registered nurses in this specific environment (Carayon & Gürses, 2005:287). The objectives of this study therefore are to explore and describe the experiences of registered nurses of their work environment in a critical care unit and to make recommendations that will assist registered nurses working in a critical care unit. A qualitative, explorative, descriptive and contextual research design will be utilised. Data will be collected by means of semi-structured interviews and analysed according to the framework provided by Tesch (in Cresswell, 2003:192). Purposive sampling will be used to select a sample of registered nurses working in a critical care environment. Guba’s model (in Krefting, 1991) will be utilised to verify data and to ensure trustworthiness of the study. Ethical considerations will be adhered to throughout the study. Once data has been analysed, recommendations will be made that will assist registered nurses working in a critical care unit.
- Full Text:
- Date Issued: 2009
The cultural determinants of success in Indian owned family businesses
- Authors: Adams, Leigh Christie
- Date: 2009
- Subjects: Family-owned business enterprises -- Management , Indian business enterprises , Small business -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8543 , http://hdl.handle.net/10948/1258 , Family-owned business enterprises -- Management , Indian business enterprises , Small business -- Management
- Description: Family owned businesses play a vital role in the economy of a country, therefore their sustainability and succession is a topic that requires adequate research and analysis. This is required to determine the impact and contribution at a socioeconomic level and future development of the family owned business. Within the Nelson Mandela Metropolitan area previous research has been conducted analysing the above with regard to Greek family businesses. There is a little evidence to suggest similar studies have been conducted on Indian owned family businesses, specifically businesses operating at a third generation level. This research will therefore analyse Indian owned family businesses that are at a minimum level of third generation within the Nelson Mandela Metropolitan area. The purpose is to investigate whether there is any specific cultural attributes of the Indian culture which have contributed to their success.
- Full Text:
- Date Issued: 2009
- Authors: Adams, Leigh Christie
- Date: 2009
- Subjects: Family-owned business enterprises -- Management , Indian business enterprises , Small business -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8543 , http://hdl.handle.net/10948/1258 , Family-owned business enterprises -- Management , Indian business enterprises , Small business -- Management
- Description: Family owned businesses play a vital role in the economy of a country, therefore their sustainability and succession is a topic that requires adequate research and analysis. This is required to determine the impact and contribution at a socioeconomic level and future development of the family owned business. Within the Nelson Mandela Metropolitan area previous research has been conducted analysing the above with regard to Greek family businesses. There is a little evidence to suggest similar studies have been conducted on Indian owned family businesses, specifically businesses operating at a third generation level. This research will therefore analyse Indian owned family businesses that are at a minimum level of third generation within the Nelson Mandela Metropolitan area. The purpose is to investigate whether there is any specific cultural attributes of the Indian culture which have contributed to their success.
- Full Text:
- Date Issued: 2009
Evaluation of the effect of Pelargonium reniforme Curtis extract on alcohol induced liver damage in Nkonkobe Municipality Eastern Cape Province South Africa
- Authors: Adewusi, Emmanuel Adekanmi
- Date: 2009
- Subjects: Plants -- Therapeutic use , Alcoholism -- South Africa -- Eastern Cape , Hepatolenticular degeneration , Pelargoniums , Plant extracts , Plant bioassay , Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Ethnobotany)
- Identifier: vital:11883 , http://hdl.handle.net/10353/263 , Plants -- Therapeutic use , Alcoholism -- South Africa -- Eastern Cape , Hepatolenticular degeneration , Pelargoniums , Plant extracts , Plant bioassay , Medicinal plants -- South Africa -- Eastern Cape
- Description: Alcohol abuse is a very common practice (just like in many other parts of the world) in Nkonkobe Municipality, Eastern Cape Province, South Africa. This is associated with liver disease. An ethnobotanical survey of plants used for the treatment of alcohol-induced liver damage in Nkonkobe Municipality was conducted. During the survey and also from information gathered in the literature, Pelargonium reniforme Curtis, was prominently mentioned, among other plants, as the species used generally for the treatment of alcohol-induced liver damage. This project was designed to evaluate the effects of the plant on alcohol-induced liver damage, including its antioxidant and antimicrobial properties. It also involves safety evaluation studies to determine if the plant is safe for consumption. Studies using rats of the Wistar strain were carried out to determine the protective and curative effects of P. reniforme on alcohol-induced liver damage. Results obtained showed that the plant extract can protect the liver cells as well as enhance recovery from tissue damage. The plant also showed good antimicrobial and antioxidant activity and this further validates its use in the treatment of liver diseases. Safety evaluation studies of the extract were carried out by investigating the effects of the oral administration on some haematological and biochemical parameters in male Wistar rats. The results obtained from the study suggest that the plant extract is not toxic at the doses used and is therefore safe for medicinal uses. The results of the various bioassays carried out in this project have justified the traditional uses of P. reniforme for the treatment of alcohol-induced liver damage.
- Full Text:
- Date Issued: 2009
- Authors: Adewusi, Emmanuel Adekanmi
- Date: 2009
- Subjects: Plants -- Therapeutic use , Alcoholism -- South Africa -- Eastern Cape , Hepatolenticular degeneration , Pelargoniums , Plant extracts , Plant bioassay , Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Ethnobotany)
- Identifier: vital:11883 , http://hdl.handle.net/10353/263 , Plants -- Therapeutic use , Alcoholism -- South Africa -- Eastern Cape , Hepatolenticular degeneration , Pelargoniums , Plant extracts , Plant bioassay , Medicinal plants -- South Africa -- Eastern Cape
- Description: Alcohol abuse is a very common practice (just like in many other parts of the world) in Nkonkobe Municipality, Eastern Cape Province, South Africa. This is associated with liver disease. An ethnobotanical survey of plants used for the treatment of alcohol-induced liver damage in Nkonkobe Municipality was conducted. During the survey and also from information gathered in the literature, Pelargonium reniforme Curtis, was prominently mentioned, among other plants, as the species used generally for the treatment of alcohol-induced liver damage. This project was designed to evaluate the effects of the plant on alcohol-induced liver damage, including its antioxidant and antimicrobial properties. It also involves safety evaluation studies to determine if the plant is safe for consumption. Studies using rats of the Wistar strain were carried out to determine the protective and curative effects of P. reniforme on alcohol-induced liver damage. Results obtained showed that the plant extract can protect the liver cells as well as enhance recovery from tissue damage. The plant also showed good antimicrobial and antioxidant activity and this further validates its use in the treatment of liver diseases. Safety evaluation studies of the extract were carried out by investigating the effects of the oral administration on some haematological and biochemical parameters in male Wistar rats. The results obtained from the study suggest that the plant extract is not toxic at the doses used and is therefore safe for medicinal uses. The results of the various bioassays carried out in this project have justified the traditional uses of P. reniforme for the treatment of alcohol-induced liver damage.
- Full Text:
- Date Issued: 2009
Valuing preferences for freshwater inflows into selected Western and Southern Cape estuaries
- Authors: Akoto, William
- Date: 2009
- Subjects: Estuarine ecology -- South Africa , Freshwater ecology -- South Africa , Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8992 , http://hdl.handle.net/10948/915 , Estuarine ecology -- South Africa , Freshwater ecology -- South Africa , Estuaries -- South Africa
- Description: An estuary is the last stage of a river. It is where the river meets the sea. Estuaries are one of the most significant features of the South African coastline. In recent years, South Africa has witnessed an increase in the demand for freshwater for both industrial and domestic purposes. At the same time, there has been a gradual deterioration of river systems and their catchments. To add to this, there has been a gradual reduction in the amount of recorded rainfall, which is the primary source of freshwater for rivers. This has resulted in decreased freshwater inflow into estuaries, a situation which poses a serious threat to the biological functioning of these estuaries and the services rendered to its recreational users. A deterioration of estuary services reduces the yield for subsistence households and their appeal for recration. This study uses the contingent valuation method as its primary methodology to elicit users' willingness-to-pay to reduce the negative impacts of reduced freshwater inflow into selected western and southern Cape estuaries. Eight estuaries were selected for this study; the Breede, Duiwenhoks, Great Berg, Kleinemond West, Mhlathuze, Swartvlei and Olifants estuaries. The contingent valuation (CV) method is widely used for studies of this nature because of its ability to capture active, passive and non-use values. The CV method involves directly asking people how much they would be willing to pay for specific environmental services. In this case, users were asked what they would be willing to pay to sustain freshwater inflows into selected estuaries in order to prevent the negative impacts of reduced inflows. The travel cost method (TCM) was uesed to generate an alternative comparative set of values for the purposes of convergence testing. This is because convergence testing is highly desirable as a validity test for CV estimates.
- Full Text:
- Date Issued: 2009
- Authors: Akoto, William
- Date: 2009
- Subjects: Estuarine ecology -- South Africa , Freshwater ecology -- South Africa , Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8992 , http://hdl.handle.net/10948/915 , Estuarine ecology -- South Africa , Freshwater ecology -- South Africa , Estuaries -- South Africa
- Description: An estuary is the last stage of a river. It is where the river meets the sea. Estuaries are one of the most significant features of the South African coastline. In recent years, South Africa has witnessed an increase in the demand for freshwater for both industrial and domestic purposes. At the same time, there has been a gradual deterioration of river systems and their catchments. To add to this, there has been a gradual reduction in the amount of recorded rainfall, which is the primary source of freshwater for rivers. This has resulted in decreased freshwater inflow into estuaries, a situation which poses a serious threat to the biological functioning of these estuaries and the services rendered to its recreational users. A deterioration of estuary services reduces the yield for subsistence households and their appeal for recration. This study uses the contingent valuation method as its primary methodology to elicit users' willingness-to-pay to reduce the negative impacts of reduced freshwater inflow into selected western and southern Cape estuaries. Eight estuaries were selected for this study; the Breede, Duiwenhoks, Great Berg, Kleinemond West, Mhlathuze, Swartvlei and Olifants estuaries. The contingent valuation (CV) method is widely used for studies of this nature because of its ability to capture active, passive and non-use values. The CV method involves directly asking people how much they would be willing to pay for specific environmental services. In this case, users were asked what they would be willing to pay to sustain freshwater inflows into selected estuaries in order to prevent the negative impacts of reduced inflows. The travel cost method (TCM) was uesed to generate an alternative comparative set of values for the purposes of convergence testing. This is because convergence testing is highly desirable as a validity test for CV estimates.
- Full Text:
- Date Issued: 2009
Investigation of the effects of 2000 & 2007 flooding on food security in two East African countries
- Authors: Albertsen, Jo-Anne Rose
- Date: 2009
- Subjects: Food security -- Environmental aspects -- Africa, Eastern , Floods -- Africa, Eastern , Agriculture -- Economic aspects -- Africa, Eastern
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9035 , http://hdl.handle.net/10948/916 , Food security -- Environmental aspects -- Africa, Eastern , Floods -- Africa, Eastern , Agriculture -- Economic aspects -- Africa, Eastern
- Description: Flooding has been identified as the predominant, environmental generator of food emergencies. Climate change and climate variability have been blamed for these extreme weather events, which are envisioned to affect the future food security and nutritional status of populations across the African continent. It is thus expected that these weather phenomena will continue to increase in frequency and intensity as climate change progresses. Already, climate change has had a dramatic effect on the natural world with increased desertification, warming oceans, rising temperatures and changing weather patterns. In turn, this has affected agriculture and fishing, which subsequently determines the availability of food. On the contrary, weather alone, is not the sole contributing factor to problems that are associated with food security/insecurity. Elements embedded within a political, social, economical, and/or other, context also serve to contribute to how a population or individual experiences food security. It is therefore imperative that these aspects from the social or developmental arena are considered in conjunction with aspects from the natural or environmental sciences. Such a holistic approach to subjects relating to climate change and development will eventually lead to the realisation of sustainable development, which in turn serves to protect human security in the long-term. The research was primarily directed at examining how flooding affects food security and what can be done to avoid, or cope with, a potential food crisis. The above-mentioned social and developmental features shaped the scope of this research, giving rise to an investigation which transcended the confines of flooding as an independent cause and consequence of food insecurity. With East Africa as a focal point, Mozambique and Zambia emerged as the most affected countries with millions of people affected by these devastating waters in 2000 and 2007, respectively. Due to the past nature of the events, it was most appropriate to utilise statistics from sources such as existing databases, reports and articles. Some of the topics that were included in the investigation examined the causes and consequences of the flooding and the management of these disasters. These topics were scrutinised using both qualitative and quantitative dimensions of research, so that an interesting and viable study could be undertaken. ii The research found that frequent and severe flood disasters increase a population‟s vulnerability to food insecurity, as a wide variety of assets, structures and infrastructures are destroyed. However, with careful management, planning and adaptation, many of these unwanted consequences can be avoided or swiftly overcome. Both Mozambique and Zambia were found to be countries that were determined to overcome the barriers associated with climate change and its subsequent extreme weather events. This positively indicated that they were committed to the development process and the wellbeing of their populations. Apart from introducing the topic surrounding the influence of flooding on food security in East Africa, one of the main goals of this research was to gather recommendations and suggestions for avoiding or managing issues that could hamper food security. This ultimately forms an important source of reference for governmental and non-governmental institutions dealing with flooding and food security. Even though Mozambique and Zambia were chosen as the cases for investigation, many of the recommendations can be adapted and applied to countries world-wide.
- Full Text:
- Date Issued: 2009
- Authors: Albertsen, Jo-Anne Rose
- Date: 2009
- Subjects: Food security -- Environmental aspects -- Africa, Eastern , Floods -- Africa, Eastern , Agriculture -- Economic aspects -- Africa, Eastern
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9035 , http://hdl.handle.net/10948/916 , Food security -- Environmental aspects -- Africa, Eastern , Floods -- Africa, Eastern , Agriculture -- Economic aspects -- Africa, Eastern
- Description: Flooding has been identified as the predominant, environmental generator of food emergencies. Climate change and climate variability have been blamed for these extreme weather events, which are envisioned to affect the future food security and nutritional status of populations across the African continent. It is thus expected that these weather phenomena will continue to increase in frequency and intensity as climate change progresses. Already, climate change has had a dramatic effect on the natural world with increased desertification, warming oceans, rising temperatures and changing weather patterns. In turn, this has affected agriculture and fishing, which subsequently determines the availability of food. On the contrary, weather alone, is not the sole contributing factor to problems that are associated with food security/insecurity. Elements embedded within a political, social, economical, and/or other, context also serve to contribute to how a population or individual experiences food security. It is therefore imperative that these aspects from the social or developmental arena are considered in conjunction with aspects from the natural or environmental sciences. Such a holistic approach to subjects relating to climate change and development will eventually lead to the realisation of sustainable development, which in turn serves to protect human security in the long-term. The research was primarily directed at examining how flooding affects food security and what can be done to avoid, or cope with, a potential food crisis. The above-mentioned social and developmental features shaped the scope of this research, giving rise to an investigation which transcended the confines of flooding as an independent cause and consequence of food insecurity. With East Africa as a focal point, Mozambique and Zambia emerged as the most affected countries with millions of people affected by these devastating waters in 2000 and 2007, respectively. Due to the past nature of the events, it was most appropriate to utilise statistics from sources such as existing databases, reports and articles. Some of the topics that were included in the investigation examined the causes and consequences of the flooding and the management of these disasters. These topics were scrutinised using both qualitative and quantitative dimensions of research, so that an interesting and viable study could be undertaken. ii The research found that frequent and severe flood disasters increase a population‟s vulnerability to food insecurity, as a wide variety of assets, structures and infrastructures are destroyed. However, with careful management, planning and adaptation, many of these unwanted consequences can be avoided or swiftly overcome. Both Mozambique and Zambia were found to be countries that were determined to overcome the barriers associated with climate change and its subsequent extreme weather events. This positively indicated that they were committed to the development process and the wellbeing of their populations. Apart from introducing the topic surrounding the influence of flooding on food security in East Africa, one of the main goals of this research was to gather recommendations and suggestions for avoiding or managing issues that could hamper food security. This ultimately forms an important source of reference for governmental and non-governmental institutions dealing with flooding and food security. Even though Mozambique and Zambia were chosen as the cases for investigation, many of the recommendations can be adapted and applied to countries world-wide.
- Full Text:
- Date Issued: 2009
A model to measure the maturuty of smartphone security at software consultancies
- Authors: Allam, Sean
- Date: 2009
- Subjects: Computer networks -- Security measures , Capability maturity model (Computer software) , Smartphones , Wireless Internet , Mobile communication systems , Mobile computing
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: vital:11135 , http://hdl.handle.net/10353/281 , Computer networks -- Security measures , Capability maturity model (Computer software) , Smartphones , Wireless Internet , Mobile communication systems , Mobile computing
- Description: Smartphones are proliferating into the workplace at an ever-increasing rate, similarly the threats that they pose is increasing. In an era of constant connectivity and availability, information is freed up of constraints of time and place. This research project delves into the risks introduced by smartphones, and through multiple cases studies, a maturity measurement model is formulated. The model is based on recommendations from two leading information security frameworks, the COBIT 4.1 framework and ISO27002 code of practice. Ultimately, a combination of smartphone specific risks are integrated with key control recommendations, in providing a set of key measurable security maturity components. The subjective opinions of case study respondents are considered a key component in achieving a solution. The solution addresses the concerns of not only policy makers, but also the employees subjected to the security policies. Nurturing security awareness into organisational culture through reinforcement and employee acceptance is highlighted in this research project. Software consultancies can use this model to mitigate risks, while harnessing the potential strategic advantages of mobile computing through smartphone devices. In addition, this research project identifies the critical components of a smartphone security solution. As a result, a model is provided for software consultancies due to the intense reliance on information within these types of organisations. The model can be effectively applied to any information intensive organisation.
- Full Text:
- Date Issued: 2009
- Authors: Allam, Sean
- Date: 2009
- Subjects: Computer networks -- Security measures , Capability maturity model (Computer software) , Smartphones , Wireless Internet , Mobile communication systems , Mobile computing
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: vital:11135 , http://hdl.handle.net/10353/281 , Computer networks -- Security measures , Capability maturity model (Computer software) , Smartphones , Wireless Internet , Mobile communication systems , Mobile computing
- Description: Smartphones are proliferating into the workplace at an ever-increasing rate, similarly the threats that they pose is increasing. In an era of constant connectivity and availability, information is freed up of constraints of time and place. This research project delves into the risks introduced by smartphones, and through multiple cases studies, a maturity measurement model is formulated. The model is based on recommendations from two leading information security frameworks, the COBIT 4.1 framework and ISO27002 code of practice. Ultimately, a combination of smartphone specific risks are integrated with key control recommendations, in providing a set of key measurable security maturity components. The subjective opinions of case study respondents are considered a key component in achieving a solution. The solution addresses the concerns of not only policy makers, but also the employees subjected to the security policies. Nurturing security awareness into organisational culture through reinforcement and employee acceptance is highlighted in this research project. Software consultancies can use this model to mitigate risks, while harnessing the potential strategic advantages of mobile computing through smartphone devices. In addition, this research project identifies the critical components of a smartphone security solution. As a result, a model is provided for software consultancies due to the intense reliance on information within these types of organisations. The model can be effectively applied to any information intensive organisation.
- Full Text:
- Date Issued: 2009
Social enterprises, social value and job creation in Cape Town
- Authors: Amm, Kathryn Leigh
- Date: 2009
- Subjects: Job creation -- South Africa -- Cape Town , Social responsibility of business -- South Africa -- Cape Town , Economic development -- Social aspects -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9036 , http://hdl.handle.net/10948/1260 , Job creation -- South Africa -- Cape Town , Social responsibility of business -- South Africa -- Cape Town , Economic development -- Social aspects -- South Africa -- Cape Town
- Description: Social enterprises are organisations which seek to meet social needs whilst generating their own financial returns. They are becoming increasingly important in South Africa as their approach is not dependent on philanthropy and is therefore largely self-sustainable. Meeting social needs can happen in many ways, but bottom up approaches, which are driven by the poor through providing access to satisifers for fundamental needs are becoming increasingly important. The impact which social enterprises have is not clearly understood and is seldom measured. There is a need to develop tools which are able to portray the social value of these impacts. This study seeks to explore the impact of three social enterprises in Cape Town. The study focuses on the social value of job creation, a pressing need across South Africa, and a social return common to all three enterprises. The study found that a primary concern for staff was job security and earning a decent wage, and without this as a starting point other social returns are minimised. Camaraderie and a sense pride are two important social returns which are also produced. The study also showed that producing social returns must be an intentional activity, and involves a process of negotiation and understanding the needs and values of different stakeholders.
- Full Text:
- Date Issued: 2009
- Authors: Amm, Kathryn Leigh
- Date: 2009
- Subjects: Job creation -- South Africa -- Cape Town , Social responsibility of business -- South Africa -- Cape Town , Economic development -- Social aspects -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9036 , http://hdl.handle.net/10948/1260 , Job creation -- South Africa -- Cape Town , Social responsibility of business -- South Africa -- Cape Town , Economic development -- Social aspects -- South Africa -- Cape Town
- Description: Social enterprises are organisations which seek to meet social needs whilst generating their own financial returns. They are becoming increasingly important in South Africa as their approach is not dependent on philanthropy and is therefore largely self-sustainable. Meeting social needs can happen in many ways, but bottom up approaches, which are driven by the poor through providing access to satisifers for fundamental needs are becoming increasingly important. The impact which social enterprises have is not clearly understood and is seldom measured. There is a need to develop tools which are able to portray the social value of these impacts. This study seeks to explore the impact of three social enterprises in Cape Town. The study focuses on the social value of job creation, a pressing need across South Africa, and a social return common to all three enterprises. The study found that a primary concern for staff was job security and earning a decent wage, and without this as a starting point other social returns are minimised. Camaraderie and a sense pride are two important social returns which are also produced. The study also showed that producing social returns must be an intentional activity, and involves a process of negotiation and understanding the needs and values of different stakeholders.
- Full Text:
- Date Issued: 2009
Lead-radium dating of two deep-water fishes from the southern hemisphere, Patagonian toothfish (Dissostichus eleginoides) and Orange Roughy (Hoplostethus atlanticus)
- Authors: Andrews, Allen Hia
- Date: 2009
- Subjects: Fishes -- Age determination , Fishes -- Southern hemisphere -- Longevity , Fishes -- Growth , Radioactive dating , Patagonian toothfish , Patagonian toothfish -- Fisheries , Orange roughy , Orange roughy -- Fisheries , Deep-sea fishes -- Southern hemisphere , Deep-sea fisheries , Deep-sea fisheries -- Southern hemisphere
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5295 , http://hdl.handle.net/10962/d1005140
- Description: Patagonian toothfish (Dissostichus eleginoides) or "Chilean sea bass" support a valuable and controversial fishery, but the life history is little known and longevity estimates range from ~20 to more than 40 or 50 yr. In this study, lead-radium dating provided validated age estimates from juveniles to older adults, supporting the use of otoliths as accurate indicators of age. The oldest age groups were near 30 yr, which provided support for age estimates exceeding 40 or 50 yr from grow zone counts in otolith sections. Hence, scale reading, which rarely exceeds 20 years, has the potential for age underestimation. Lead-radium dating revealed what may be minor differences in age interpretation between two facilities and findings may provide an age-validated opportunity for the CCAMLR Otolith Network to reassess otolith interpretations. Orange roughy (Hoplostethus atlanticus) support a major deep-sea fishery and stock assessments often depend on age analyses, but lifespan estimates range from ~20 to over 100 yr and validation of growth zone counts remained unresolved. An early application of lead-radium dating supported centenarian ages, but the findings were met with disbelief and some studies have attempted to discredit the technique and the long lifespan. In this study, an improved lead-radium dating technique used smaller samples than previously possible and circumvented assumptions that were previously necessary. Lead-radium dating of otolith cores, the first few years of growth, provided ratios that correlated well with the ingrowth curve. This provided robust support for age estimates from otolith thin sections. Use of radiometric ages as independent age estimates indicated the fish in the oldest group were at least 93 yr. Lead-radium dating has validated a centenarian lifespan for orange roughy. To date, radium-226 has been measured in otoliths of 39 fish species ranging from the northern Pacific and Atlantic Oceans to the Southern Ocean. In total, 367 reliable radium-226 measurements were made in 36 studies since the first lead-radium dating study on fish in 1982. The activity of radium-226 measurements ranged over 3 orders of magnitude (<0.001 to >1.0 dpm.g⁻¹). An analysis revealed ontogenetic differences in radium-226 uptake that may be attributed to changes in habitat or diet. Radiometric age from otolith core studies was used to describe a radium-226 uptake time-series for some species, which revealed interesting patterns over long periods. This synopsis provides information on the uptake of radium-226 to otoliths from an environmental perspective, which can be used as a basis for future studies.
- Full Text:
- Date Issued: 2009
- Authors: Andrews, Allen Hia
- Date: 2009
- Subjects: Fishes -- Age determination , Fishes -- Southern hemisphere -- Longevity , Fishes -- Growth , Radioactive dating , Patagonian toothfish , Patagonian toothfish -- Fisheries , Orange roughy , Orange roughy -- Fisheries , Deep-sea fishes -- Southern hemisphere , Deep-sea fisheries , Deep-sea fisheries -- Southern hemisphere
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5295 , http://hdl.handle.net/10962/d1005140
- Description: Patagonian toothfish (Dissostichus eleginoides) or "Chilean sea bass" support a valuable and controversial fishery, but the life history is little known and longevity estimates range from ~20 to more than 40 or 50 yr. In this study, lead-radium dating provided validated age estimates from juveniles to older adults, supporting the use of otoliths as accurate indicators of age. The oldest age groups were near 30 yr, which provided support for age estimates exceeding 40 or 50 yr from grow zone counts in otolith sections. Hence, scale reading, which rarely exceeds 20 years, has the potential for age underestimation. Lead-radium dating revealed what may be minor differences in age interpretation between two facilities and findings may provide an age-validated opportunity for the CCAMLR Otolith Network to reassess otolith interpretations. Orange roughy (Hoplostethus atlanticus) support a major deep-sea fishery and stock assessments often depend on age analyses, but lifespan estimates range from ~20 to over 100 yr and validation of growth zone counts remained unresolved. An early application of lead-radium dating supported centenarian ages, but the findings were met with disbelief and some studies have attempted to discredit the technique and the long lifespan. In this study, an improved lead-radium dating technique used smaller samples than previously possible and circumvented assumptions that were previously necessary. Lead-radium dating of otolith cores, the first few years of growth, provided ratios that correlated well with the ingrowth curve. This provided robust support for age estimates from otolith thin sections. Use of radiometric ages as independent age estimates indicated the fish in the oldest group were at least 93 yr. Lead-radium dating has validated a centenarian lifespan for orange roughy. To date, radium-226 has been measured in otoliths of 39 fish species ranging from the northern Pacific and Atlantic Oceans to the Southern Ocean. In total, 367 reliable radium-226 measurements were made in 36 studies since the first lead-radium dating study on fish in 1982. The activity of radium-226 measurements ranged over 3 orders of magnitude (<0.001 to >1.0 dpm.g⁻¹). An analysis revealed ontogenetic differences in radium-226 uptake that may be attributed to changes in habitat or diet. Radiometric age from otolith core studies was used to describe a radium-226 uptake time-series for some species, which revealed interesting patterns over long periods. This synopsis provides information on the uptake of radium-226 to otoliths from an environmental perspective, which can be used as a basis for future studies.
- Full Text:
- Date Issued: 2009
The implementation of project work by selected grade 10 life science teachers in Namibia
- Authors: Angula, Alina Hambelela
- Date: 2009
- Subjects: Education -- Namibia Life sciences -- Study and teaching (Secondary) -- Namibia Project method in teaching -- Namibia School improvement programs -- Namibia Teachers -- Training of -- Namibia Curriculum planning -- Namibia Educational change -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1567 , http://hdl.handle.net/10962/d1003449
- Description: Prior to independence in Namibia in 1990 the education system of the day did not encourage the majority of Namibian learners to explore and investigate the wonder of the natural and physical world. The post independence education system has nurtured the study of the sciences and has emphasized participation, problem solving and independent studies. The inclusion of projects and other independent studies has been regarded as a key vehicle to develop scientific understanding and competencies related to this understanding. However, very few studies have hitherto investigated the teachers’ understanding and implementation of projects in the Namibian context. This study investigates how Grade 10 Life Science teachers understand and implement projects in selected schools in Namibia. The study focused on two teachers in two schools, a combined and a senior secondary school in the Oshikoto educational region of Namibia. The research was conducted through an interpretive case study aiming to gain a better understanding about the implementation of projects in schools. Data were collected through semi-structured interviews, classroom observation and document analysis. The findings indicate that despite the focus on projects in the Life Science syllabus and broad curriculum, policy documents do not give detailed guidelines on how projects should be planned, organized and assessed. The results revealed that knowledge about projects and their implementation is primarily informed by practical activities rather than the critical enquiries or investigations required by the Life Science curriculum policy. The study also revealed that despite the in-service training received by the two teachers participating in this study on syllabus interpretation, it is apparent from the findings that project work in these in-service programmes was neglected. This has further hampered teachers’ understanding and implementation of projects. The findings of this study point to a need for project guidelines as well as in-service programmes in this area if the stated nature and role of projects in the context of Namibian education policy is to be achieved.
- Full Text:
- Date Issued: 2009
- Authors: Angula, Alina Hambelela
- Date: 2009
- Subjects: Education -- Namibia Life sciences -- Study and teaching (Secondary) -- Namibia Project method in teaching -- Namibia School improvement programs -- Namibia Teachers -- Training of -- Namibia Curriculum planning -- Namibia Educational change -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1567 , http://hdl.handle.net/10962/d1003449
- Description: Prior to independence in Namibia in 1990 the education system of the day did not encourage the majority of Namibian learners to explore and investigate the wonder of the natural and physical world. The post independence education system has nurtured the study of the sciences and has emphasized participation, problem solving and independent studies. The inclusion of projects and other independent studies has been regarded as a key vehicle to develop scientific understanding and competencies related to this understanding. However, very few studies have hitherto investigated the teachers’ understanding and implementation of projects in the Namibian context. This study investigates how Grade 10 Life Science teachers understand and implement projects in selected schools in Namibia. The study focused on two teachers in two schools, a combined and a senior secondary school in the Oshikoto educational region of Namibia. The research was conducted through an interpretive case study aiming to gain a better understanding about the implementation of projects in schools. Data were collected through semi-structured interviews, classroom observation and document analysis. The findings indicate that despite the focus on projects in the Life Science syllabus and broad curriculum, policy documents do not give detailed guidelines on how projects should be planned, organized and assessed. The results revealed that knowledge about projects and their implementation is primarily informed by practical activities rather than the critical enquiries or investigations required by the Life Science curriculum policy. The study also revealed that despite the in-service training received by the two teachers participating in this study on syllabus interpretation, it is apparent from the findings that project work in these in-service programmes was neglected. This has further hampered teachers’ understanding and implementation of projects. The findings of this study point to a need for project guidelines as well as in-service programmes in this area if the stated nature and role of projects in the context of Namibian education policy is to be achieved.
- Full Text:
- Date Issued: 2009
An exploratory study of employee responses to the implementation of SAP R/3 and connected application portfolios (CAPs) at an energy company
- Authors: Anthony, Lizel Angelique
- Date: 2009
- Subjects: SAP R/3 , Organizational change -- South Africa , Personnel management -- South Africa , Business planning -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:16137 , http://hdl.handle.net/10948/1415 , SAP R/3 , Organizational change -- South Africa , Personnel management -- South Africa , Business planning -- South Africa
- Description: The aim of this research was to explore employee responses to the implementation of SAP R/3 and Connected Application Portfolios (CAPs) in Shell South Africa (Pty) Ltd. Downstream-One (DS-1) Business/Lubricants (B2B/Lubes) Project Implementation Programme. It assessed whether employees accepted or rejected change prior to the implementation of SAP R/3 and CAP’s. In 2005 globally Shell launched its Enterprise Resource Planning (ERP) implementation. Its 16th implementation was conducted in Shell South Africa (Pty) Ltd. (Shell SA) in 2008. This research was conducted using a qualitative approach.
- Full Text:
- Date Issued: 2009
- Authors: Anthony, Lizel Angelique
- Date: 2009
- Subjects: SAP R/3 , Organizational change -- South Africa , Personnel management -- South Africa , Business planning -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:16137 , http://hdl.handle.net/10948/1415 , SAP R/3 , Organizational change -- South Africa , Personnel management -- South Africa , Business planning -- South Africa
- Description: The aim of this research was to explore employee responses to the implementation of SAP R/3 and Connected Application Portfolios (CAPs) in Shell South Africa (Pty) Ltd. Downstream-One (DS-1) Business/Lubricants (B2B/Lubes) Project Implementation Programme. It assessed whether employees accepted or rejected change prior to the implementation of SAP R/3 and CAP’s. In 2005 globally Shell launched its Enterprise Resource Planning (ERP) implementation. Its 16th implementation was conducted in Shell South Africa (Pty) Ltd. (Shell SA) in 2008. This research was conducted using a qualitative approach.
- Full Text:
- Date Issued: 2009
Unearthed : personifications of widowhood and acts of memory : volume 1 and 2
- Authors: Arbi, Linda Margaret
- Date: 2009
- Subjects: Widowhood -- Social aspects -- South Africa Widowhood -- Social aspects -- Cape of Good Hope (South Africa) Widows in art -- South Africa Widows in art -- Cape of Good Hope (South Africa) Memory in art -- South Africa Memory in art -- Cape of Good Hope (South Africa)
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2428 , http://hdl.handle.net/10962/d1002225
- Description: By researching visual traditions of representing widows in relation to a social role, I explore how these may be related to processes of mourning and memory. My study begins with an historical reading and, along with an analysis of Renaissance widow portraiture, I trace the experiences of widows in the Cape of Good Hope. For the purposes of this thesis, I have selected images of widows to investigate memory-work particularly when speaking of loss. I re-view these memory processes through recent historical and art historical discourse with reference to contemporary South African artworks in order to understand how public memory is formed by way of visual documentation. These narratives around widowhood have informed the subject matter for my Master’s exhibition and shed light on my own experience as a widow. The interaction between objects and memory are of particular interest and manifest in my studio art practice.
- Full Text:
- Date Issued: 2009
- Authors: Arbi, Linda Margaret
- Date: 2009
- Subjects: Widowhood -- Social aspects -- South Africa Widowhood -- Social aspects -- Cape of Good Hope (South Africa) Widows in art -- South Africa Widows in art -- Cape of Good Hope (South Africa) Memory in art -- South Africa Memory in art -- Cape of Good Hope (South Africa)
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2428 , http://hdl.handle.net/10962/d1002225
- Description: By researching visual traditions of representing widows in relation to a social role, I explore how these may be related to processes of mourning and memory. My study begins with an historical reading and, along with an analysis of Renaissance widow portraiture, I trace the experiences of widows in the Cape of Good Hope. For the purposes of this thesis, I have selected images of widows to investigate memory-work particularly when speaking of loss. I re-view these memory processes through recent historical and art historical discourse with reference to contemporary South African artworks in order to understand how public memory is formed by way of visual documentation. These narratives around widowhood have informed the subject matter for my Master’s exhibition and shed light on my own experience as a widow. The interaction between objects and memory are of particular interest and manifest in my studio art practice.
- Full Text:
- Date Issued: 2009
Student's van Hiele levels of geometric thought and conception in plane geometry: a collective case study of Nigeria and South Africa
- Authors: Atebe, Humphrey Uyouyo
- Date: 2009
- Subjects: Geometry -- Study and teaching (Secondary) -- Nigeria -- Case studies Geometry -- Study and teaching (Secondary) -- South Africa -- Case studies Mathematics -- Study and teaching (Secondary) -- Nigeria -- Case studies Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1777 , http://hdl.handle.net/10962/d1003662
- Description: This study is inspired by and utilises the van Hiele theory of geometric thought levels, currently acclaimed as one of the best frameworks for studying teaching and learning processes in geometry. The study aims both to explore and explicate the van Hiele levels of geometric thinking of a selected group of grade 10, 11 and 12 learners in Nigerian and South African schools. The study further aims to provide a rich and indepth description of the geometry instructional practices that possibly contributed to the levels of geometric conceptualisation exhibited by this cohort of high school learners. This collective case study, presented in two volumes, is oriented within an interpretive research paradigm and characterised by both qualitative and quantitative methods. The sample for the study comprised a total of 144 mathematics learners and 6 mathematics teachers from Nigeria and South Africa. They were selected using both purposive and stratified sampling techniques. In using the van Hiele model to interrogate both learners’ levels of geometric conceptualisation and teaching methods in geometry classrooms, the study employs a qualitative and qunatitative approach to the data-collection process, involving the use of questionnaires (in the form of various pen-and-paper tests, hands-on activity-based tests), interviews and classroom videos. Although the data analysis was done largely through descriptive statistics, the whole process inevitably incorporated elements of inferential statistics (e.g. ANOVA and Tukey HSD post-hoc test) in the quest for indepth analysis and deeper interpretation of the data. Learners were assigned to various van Hiele levels, mainly according to Usiskin’s (1982) forced van Hiele level determination scheme. The whole process of analysing the classroom videos involved a consultative panel of 4 observers and 3 critical readers, using the checklist of van Hiele phase descriptors to guide the analysis process. Concerning learners’ levels of geometric conceptualisation, the results from this study reveal that the most of the learners were not yet ready for the formal deductive study of school geometry, as only 2% and 3% of them were respectively at van Hiele levels 3 and 4, while 47%, 22% and 24% were at levels 0, 1 and 2, respectively. More learners from the Nigerian subsample (53%) were at van Hiele level 0 than learners from the South African subsample (41%) at this level. No learner from the Nigerian subsample was at van Hiele level 4, while 6% of the South African learners were at level 4. In general, learners from the Nigerian subsample had a poorer knowledge of school geometry than their peers from the South African subsample, as learners from the latter subsample obtained significantly higher mean scores in the van Hiele Geometry Test (VHGT) and each of the other tests used in this study. Results relating to gender differences in performance generally favour the male learners in this study. For each of the participating schools, learners’ van Hiele levels (as determined by their scores on the VHGT) strongly correlate with their performance in geometry content tests and mathematics generally. For each of the Nigerian and South African subsamples, for n ≤ 2, learners at van Hiele level n obtained higher means on nearly all the tests administered in this study than their peers at level n–1. This finding provides support for the hierarchical property of the van Hiele levels.
- Full Text:
- Date Issued: 2009
- Authors: Atebe, Humphrey Uyouyo
- Date: 2009
- Subjects: Geometry -- Study and teaching (Secondary) -- Nigeria -- Case studies Geometry -- Study and teaching (Secondary) -- South Africa -- Case studies Mathematics -- Study and teaching (Secondary) -- Nigeria -- Case studies Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1777 , http://hdl.handle.net/10962/d1003662
- Description: This study is inspired by and utilises the van Hiele theory of geometric thought levels, currently acclaimed as one of the best frameworks for studying teaching and learning processes in geometry. The study aims both to explore and explicate the van Hiele levels of geometric thinking of a selected group of grade 10, 11 and 12 learners in Nigerian and South African schools. The study further aims to provide a rich and indepth description of the geometry instructional practices that possibly contributed to the levels of geometric conceptualisation exhibited by this cohort of high school learners. This collective case study, presented in two volumes, is oriented within an interpretive research paradigm and characterised by both qualitative and quantitative methods. The sample for the study comprised a total of 144 mathematics learners and 6 mathematics teachers from Nigeria and South Africa. They were selected using both purposive and stratified sampling techniques. In using the van Hiele model to interrogate both learners’ levels of geometric conceptualisation and teaching methods in geometry classrooms, the study employs a qualitative and qunatitative approach to the data-collection process, involving the use of questionnaires (in the form of various pen-and-paper tests, hands-on activity-based tests), interviews and classroom videos. Although the data analysis was done largely through descriptive statistics, the whole process inevitably incorporated elements of inferential statistics (e.g. ANOVA and Tukey HSD post-hoc test) in the quest for indepth analysis and deeper interpretation of the data. Learners were assigned to various van Hiele levels, mainly according to Usiskin’s (1982) forced van Hiele level determination scheme. The whole process of analysing the classroom videos involved a consultative panel of 4 observers and 3 critical readers, using the checklist of van Hiele phase descriptors to guide the analysis process. Concerning learners’ levels of geometric conceptualisation, the results from this study reveal that the most of the learners were not yet ready for the formal deductive study of school geometry, as only 2% and 3% of them were respectively at van Hiele levels 3 and 4, while 47%, 22% and 24% were at levels 0, 1 and 2, respectively. More learners from the Nigerian subsample (53%) were at van Hiele level 0 than learners from the South African subsample (41%) at this level. No learner from the Nigerian subsample was at van Hiele level 4, while 6% of the South African learners were at level 4. In general, learners from the Nigerian subsample had a poorer knowledge of school geometry than their peers from the South African subsample, as learners from the latter subsample obtained significantly higher mean scores in the van Hiele Geometry Test (VHGT) and each of the other tests used in this study. Results relating to gender differences in performance generally favour the male learners in this study. For each of the participating schools, learners’ van Hiele levels (as determined by their scores on the VHGT) strongly correlate with their performance in geometry content tests and mathematics generally. For each of the Nigerian and South African subsamples, for n ≤ 2, learners at van Hiele level n obtained higher means on nearly all the tests administered in this study than their peers at level n–1. This finding provides support for the hierarchical property of the van Hiele levels.
- Full Text:
- Date Issued: 2009
An investigation into the persistence of traditional teaching methods in grade 9 mathematics classrooms in Rundu : a case study
- Authors: Ausiku, Charity M
- Date: 2009
- Subjects: Mathematics -- Study and teaching (Secondary) -- Namibia -- Case studies Mathematics teachers -- Training of -- Namibia -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1852 , http://hdl.handle.net/10962/d1004461
- Description: I embarked upon this study to investigate mathematics teachers' practices that have led to the persistence of traditional teaching methods in grade 9 mathematics classrooms in Rundu. The study was conducted from a learner-centred (L-C) perspective or reform approach in the Namibian context. It is a qualitative study oriented in the interpretive paradigm- a paradigm that seeks to understand the meanings attached to human actions. The participants involved in this study were purposively selected and they are composed of two mathematics teachers and their grade 9 learners. This study was conducted at two schools in Rundu. One is an urban school while the other one is a rural school on the outskirts of Rundu. The research tools employed in this study are questionnaires, interviews and observations. The questionnaires were used to identify and select my participants while the observations were used to investigate the participants teaching strategies. The purpose of the interviews was mainly to investigate teachers' understanding, interpretation and implementation of learner-centre education (LCE). Amongst other findings, this study reveals that inadequate teacher-training, controversial educational policies and challenges such as overcrowdedness in mathematics classrooms, lack of teaching and learning materials, lack of cooperation among mathematics teachers and learners' negative attitude towards mathematics are some of the contributing factors to the persistence of traditional teaching methods in mathematics classrooms. Moreover, the study reveals that the persistence of traditional teaching methods in mathematics classes can no longer be attributed to the lack of understanding of LCE. The teachers in this study seem to be well acquainted with the theoretical aspect of the LCE framework while the implementation aspect seems to be a concern.
- Full Text:
- Date Issued: 2009
- Authors: Ausiku, Charity M
- Date: 2009
- Subjects: Mathematics -- Study and teaching (Secondary) -- Namibia -- Case studies Mathematics teachers -- Training of -- Namibia -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1852 , http://hdl.handle.net/10962/d1004461
- Description: I embarked upon this study to investigate mathematics teachers' practices that have led to the persistence of traditional teaching methods in grade 9 mathematics classrooms in Rundu. The study was conducted from a learner-centred (L-C) perspective or reform approach in the Namibian context. It is a qualitative study oriented in the interpretive paradigm- a paradigm that seeks to understand the meanings attached to human actions. The participants involved in this study were purposively selected and they are composed of two mathematics teachers and their grade 9 learners. This study was conducted at two schools in Rundu. One is an urban school while the other one is a rural school on the outskirts of Rundu. The research tools employed in this study are questionnaires, interviews and observations. The questionnaires were used to identify and select my participants while the observations were used to investigate the participants teaching strategies. The purpose of the interviews was mainly to investigate teachers' understanding, interpretation and implementation of learner-centre education (LCE). Amongst other findings, this study reveals that inadequate teacher-training, controversial educational policies and challenges such as overcrowdedness in mathematics classrooms, lack of teaching and learning materials, lack of cooperation among mathematics teachers and learners' negative attitude towards mathematics are some of the contributing factors to the persistence of traditional teaching methods in mathematics classrooms. Moreover, the study reveals that the persistence of traditional teaching methods in mathematics classes can no longer be attributed to the lack of understanding of LCE. The teachers in this study seem to be well acquainted with the theoretical aspect of the LCE framework while the implementation aspect seems to be a concern.
- Full Text:
- Date Issued: 2009
Grade 10 life science teachers' understanding and development of critical thinking skills in selected schools in Namibia
- Authors: Avia, Ndiyakuphi
- Date: 2009
- Subjects: Education -- Namibia Life sciences -- Study and teaching (Secondary) -- Namibia Critical thinking -- Study and teaching (Secondary) -- Namibia Education -- Curricula -- Namibia Educational change -- Namibia Teachers -- Training of -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1550 , http://hdl.handle.net/10962/d1003432
- Description: The educational reform policy in Namibia adopted the principles and practice of learner-centred education, a policy based on constructivist epistemology. This approach emphasises that learners are constructors of knowledge and that they must discover information and construct their own learning. Constructivist techniques require the use of critical thinking through learners’ active involvement in the learning process. The aim is for learners to use critical thinking to identify problems, ask questions, reason, examine and solve problems in real situations and make sound decisions. This approach provides learners with activities and experiences that stimulate them to learn to think for themselves and to ask questions. Therefore, teachers need to design activities that require learners to think critically and act independently through mastering these various modes of inquiry. The purpose of this study was to explore how the selected Grade 10 Life Science teachers understand and implement critical thinking in their teaching practice. I conducted the study in two secondary schools from the Omusati region in Namibia using a case study to gain insight into the implementation of critical thinking. Three data collection instruments: interviews, document analysis and class observations were used. The reason for conducting this study was to gain a better understanding of how teachers use various strategies to foster critical thinking skills in Life Science and the challenges they experience in teaching in secondary schools. The results of the study revealed that teachers have a theoretical understanding of what critical thinking implies and the role it plays in learning. They are also aware of the strategies used to develop critical thinking skills. However, these theoretical perspectives do not reflect in their teaching in that some of the strategies that the teachers used did not bring about meaningful learning. Learners are still required to recall factual knowledge, thus active involvement of the learners is limited. The study also revealed that there are specific issues that hamper the implementation of critical thinking, which include superficial understanding of learner-centered education, teacher-tell approach, overcrowded curriculum, inexplicit syllabus, lack of good examples from the textbooks and examinations, too short lesson periods, lack of language proficiency and lack of professional development. The findings indicate that despite the theoretical understanding of the teachers in this study, their actual practice of developing critical thinking skills is problematic. The study concludes that teachers should be encouraged to design better-structured activities in order to involve learners beyond just being listeners. In light of these findings, the study recognizes a need for ongoing in-service professional development to support teachers in modelling critical thinking to their learners and to teach them to think critically. The findings of the study will serve to inform both my and my colleague’s professional practice as advisory teachers with regard to what to focus on when advising and supporting the teachers in schools.
- Full Text:
- Date Issued: 2009
- Authors: Avia, Ndiyakuphi
- Date: 2009
- Subjects: Education -- Namibia Life sciences -- Study and teaching (Secondary) -- Namibia Critical thinking -- Study and teaching (Secondary) -- Namibia Education -- Curricula -- Namibia Educational change -- Namibia Teachers -- Training of -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1550 , http://hdl.handle.net/10962/d1003432
- Description: The educational reform policy in Namibia adopted the principles and practice of learner-centred education, a policy based on constructivist epistemology. This approach emphasises that learners are constructors of knowledge and that they must discover information and construct their own learning. Constructivist techniques require the use of critical thinking through learners’ active involvement in the learning process. The aim is for learners to use critical thinking to identify problems, ask questions, reason, examine and solve problems in real situations and make sound decisions. This approach provides learners with activities and experiences that stimulate them to learn to think for themselves and to ask questions. Therefore, teachers need to design activities that require learners to think critically and act independently through mastering these various modes of inquiry. The purpose of this study was to explore how the selected Grade 10 Life Science teachers understand and implement critical thinking in their teaching practice. I conducted the study in two secondary schools from the Omusati region in Namibia using a case study to gain insight into the implementation of critical thinking. Three data collection instruments: interviews, document analysis and class observations were used. The reason for conducting this study was to gain a better understanding of how teachers use various strategies to foster critical thinking skills in Life Science and the challenges they experience in teaching in secondary schools. The results of the study revealed that teachers have a theoretical understanding of what critical thinking implies and the role it plays in learning. They are also aware of the strategies used to develop critical thinking skills. However, these theoretical perspectives do not reflect in their teaching in that some of the strategies that the teachers used did not bring about meaningful learning. Learners are still required to recall factual knowledge, thus active involvement of the learners is limited. The study also revealed that there are specific issues that hamper the implementation of critical thinking, which include superficial understanding of learner-centered education, teacher-tell approach, overcrowded curriculum, inexplicit syllabus, lack of good examples from the textbooks and examinations, too short lesson periods, lack of language proficiency and lack of professional development. The findings indicate that despite the theoretical understanding of the teachers in this study, their actual practice of developing critical thinking skills is problematic. The study concludes that teachers should be encouraged to design better-structured activities in order to involve learners beyond just being listeners. In light of these findings, the study recognizes a need for ongoing in-service professional development to support teachers in modelling critical thinking to their learners and to teach them to think critically. The findings of the study will serve to inform both my and my colleague’s professional practice as advisory teachers with regard to what to focus on when advising and supporting the teachers in schools.
- Full Text:
- Date Issued: 2009
Access to credit and the effect of credit constraints on household welfare in the Eastern Cape province, South Africa
- Baiyegunhi, Lloyd-James Segun
- Authors: Baiyegunhi, Lloyd-James Segun
- Date: 2009
- Subjects: Rural poor -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape , Investments -- South Africa -- Eastern Cape , Finance -- South Africa -- Eastern Cape , Credit -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Agricultural Economics)
- Identifier: vital:11153 , http://hdl.handle.net/10353/d1000977 , Rural poor -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape , Investments -- South Africa -- Eastern Cape , Finance -- South Africa -- Eastern Cape , Credit -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Description: In recent years, concern about food safety linked to health issues has seen a rise in private food safety standards in addition to the regulations set by the Food and Agriculture Organisation (FAO) in collaboration with the World Health Organisation (WHO). These have presented challenges to producers and exporters of agricultural food products especially the producers of fresh fruits and vegetables. In spite of the food safety-linked challenges from the demand side, the vast range of business-environment forces pose equally formidable challenges that negatively impact on the exporting industries’ ability to maintain or improve their market shares and their ability to compete in world markets. The objective of this study was therefore to establish the competitiveness of the South African citrus industry in the international markets within this prevailing scenario. Due to the diversity of the definitions of competitiveness as a concept, this study formulated the following working definition: “the ability to create, deliver and maintain value and constant market share through strategic management of the industrial environment or competitiveness drivers”. This was based on the understanding that the international market shares of an industry are a function of forces in the business environment which range from intra-industry, external and national as well as the international elements. The unit of analysis were the citrus producers engaged in export of their products and the study made use of 151 responses by producers. The study adopted a five-step approach to the analysis of the performance of the South African citrus industry in the global markets, starting with the analysis of the Constant Market Share (CMS) of the South African citrus industry in various world markets, establishing the impact of the business environmental factors upon competitiveness, establishing the costs of compliance with private food safety standards, determining the non-price benefits of compliance with the standards, as well as highlighting the strategies for enhancing long-term competitiveness of the industry in the international markets. South Africa is one of the top three countries dominating the citrus fruit export market. Since its entry into the citrus fruit exports market in the 1900s, the industry has sustained its activity in the international market. The Constant Market Share Analysis shows that, amidst the challenges on the international market side, and the changes in the business environment, over much of which the industry has limited control and influence, the industry has maintained its competitive advantage in several markets. The CMS shows that South Africa’s lemons are competitive in America. Despite a negative trend, the South African grapefruit has been competitive in France, Greece, Italy, the Netherlands and Spain. Oranges have been competitive in the Greece, Italy, Portugal, UK, Asian and Northern Europe markets. Competitiveness in these markets has been due to the inherent competitiveness of the industry. Competitiveness in such markets as the Middle East has been attributed to the relatively rapid growth of these markets. The South African citrus industry has similarly undergone many major processes of transformation. The business environmental factors influencing its performance have ranged reform to the challenges beyond the country’s borders. These factors directly and indirectly affect the performance of the industry in the export market. They have influenced the flow of fruits into different international destinations. Of major concern are the food safety and private standards. Challenges in traditional markets as well as opportunities presented by demand from newly emerging citrus consuming nations have seen a diversification in the marketing of the South African citrus. The intensity of competition in the global market is reflected by the fluctuations in the market shares in different markets as well as the increase and fluctuations of fruit rejection rates in some lucrative markets such as America. A combination of challenging national environmental forces and stringent demand conditions negatively impact on revenues especially from markets characterised by price competitiveness. This study identified cost of production, foreign market support systems, adaptability, worker skills, challenges of management in an international environment and government policies such as labour and trade policies as some of the most influential obstacles to competitiveness. Some of the most competiveness-enhancing factors were market availability, market size, market information, market growth and the availability of research institutions. However, compliance with private standards still poses a challenge to the exporters. The different performance levels of the industry in various markets prove the dissimilarity of the demand conditions in the global market. These are supported by the negative influence associated with the foreign market support regimes as well as the challenges associated with compliance with private food safety standards. While market availability, market growth, market information and size were identified as enhancing competitiveness, the fluctuations and inconsistencies in the competitiveness of the industry in different foreign markets require more than finding markets. Resource allocation by both the government and the industry may need to take into account the off-setting of the national challenges and support of farmers faced with distorted and unfair international playing fields. Otherwise, market availability is not a challenge for the industry save meeting the specifications therewith as well as price competitiveness which is unattainable for the South African citrus producers faced with high production costs. For the purposes of further study, it is recommended that account should be taken of all the products marketed by the industry (including processed products such as fruit juices) in order to have a whole picture of the competitiveness of the industry in the international market. This study also proffers a new theoretical framework for the analysis of the business environment for the citrus industry and other agro-businesses. This framework takes into account the indispensability of the food safety standards and measures as well as the diversity of the global consumer and the non-negotiability of food trade for the sustenance of the growing population.
- Full Text:
- Date Issued: 2009
- Authors: Baiyegunhi, Lloyd-James Segun
- Date: 2009
- Subjects: Rural poor -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape , Investments -- South Africa -- Eastern Cape , Finance -- South Africa -- Eastern Cape , Credit -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Agricultural Economics)
- Identifier: vital:11153 , http://hdl.handle.net/10353/d1000977 , Rural poor -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape , Investments -- South Africa -- Eastern Cape , Finance -- South Africa -- Eastern Cape , Credit -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape
- Description: In recent years, concern about food safety linked to health issues has seen a rise in private food safety standards in addition to the regulations set by the Food and Agriculture Organisation (FAO) in collaboration with the World Health Organisation (WHO). These have presented challenges to producers and exporters of agricultural food products especially the producers of fresh fruits and vegetables. In spite of the food safety-linked challenges from the demand side, the vast range of business-environment forces pose equally formidable challenges that negatively impact on the exporting industries’ ability to maintain or improve their market shares and their ability to compete in world markets. The objective of this study was therefore to establish the competitiveness of the South African citrus industry in the international markets within this prevailing scenario. Due to the diversity of the definitions of competitiveness as a concept, this study formulated the following working definition: “the ability to create, deliver and maintain value and constant market share through strategic management of the industrial environment or competitiveness drivers”. This was based on the understanding that the international market shares of an industry are a function of forces in the business environment which range from intra-industry, external and national as well as the international elements. The unit of analysis were the citrus producers engaged in export of their products and the study made use of 151 responses by producers. The study adopted a five-step approach to the analysis of the performance of the South African citrus industry in the global markets, starting with the analysis of the Constant Market Share (CMS) of the South African citrus industry in various world markets, establishing the impact of the business environmental factors upon competitiveness, establishing the costs of compliance with private food safety standards, determining the non-price benefits of compliance with the standards, as well as highlighting the strategies for enhancing long-term competitiveness of the industry in the international markets. South Africa is one of the top three countries dominating the citrus fruit export market. Since its entry into the citrus fruit exports market in the 1900s, the industry has sustained its activity in the international market. The Constant Market Share Analysis shows that, amidst the challenges on the international market side, and the changes in the business environment, over much of which the industry has limited control and influence, the industry has maintained its competitive advantage in several markets. The CMS shows that South Africa’s lemons are competitive in America. Despite a negative trend, the South African grapefruit has been competitive in France, Greece, Italy, the Netherlands and Spain. Oranges have been competitive in the Greece, Italy, Portugal, UK, Asian and Northern Europe markets. Competitiveness in these markets has been due to the inherent competitiveness of the industry. Competitiveness in such markets as the Middle East has been attributed to the relatively rapid growth of these markets. The South African citrus industry has similarly undergone many major processes of transformation. The business environmental factors influencing its performance have ranged reform to the challenges beyond the country’s borders. These factors directly and indirectly affect the performance of the industry in the export market. They have influenced the flow of fruits into different international destinations. Of major concern are the food safety and private standards. Challenges in traditional markets as well as opportunities presented by demand from newly emerging citrus consuming nations have seen a diversification in the marketing of the South African citrus. The intensity of competition in the global market is reflected by the fluctuations in the market shares in different markets as well as the increase and fluctuations of fruit rejection rates in some lucrative markets such as America. A combination of challenging national environmental forces and stringent demand conditions negatively impact on revenues especially from markets characterised by price competitiveness. This study identified cost of production, foreign market support systems, adaptability, worker skills, challenges of management in an international environment and government policies such as labour and trade policies as some of the most influential obstacles to competitiveness. Some of the most competiveness-enhancing factors were market availability, market size, market information, market growth and the availability of research institutions. However, compliance with private standards still poses a challenge to the exporters. The different performance levels of the industry in various markets prove the dissimilarity of the demand conditions in the global market. These are supported by the negative influence associated with the foreign market support regimes as well as the challenges associated with compliance with private food safety standards. While market availability, market growth, market information and size were identified as enhancing competitiveness, the fluctuations and inconsistencies in the competitiveness of the industry in different foreign markets require more than finding markets. Resource allocation by both the government and the industry may need to take into account the off-setting of the national challenges and support of farmers faced with distorted and unfair international playing fields. Otherwise, market availability is not a challenge for the industry save meeting the specifications therewith as well as price competitiveness which is unattainable for the South African citrus producers faced with high production costs. For the purposes of further study, it is recommended that account should be taken of all the products marketed by the industry (including processed products such as fruit juices) in order to have a whole picture of the competitiveness of the industry in the international market. This study also proffers a new theoretical framework for the analysis of the business environment for the citrus industry and other agro-businesses. This framework takes into account the indispensability of the food safety standards and measures as well as the diversity of the global consumer and the non-negotiability of food trade for the sustenance of the growing population.
- Full Text:
- Date Issued: 2009