Assessment of antibiotic production by some marine actinomycetes belonging to the genera norcadia, saccharopolyspora and kibdellosporangium.
- Koba, Siziwe (https://orcid.org/0000-0002-6761-6403)
- Authors: Koba, Siziwe (https://orcid.org/0000-0002-6761-6403)
- Date: 2010
- Subjects: Actinobacteria , Bacteria , Actinomycetales
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/25811 , vital:64488
- Description: Antibacterial potency of the extracts of the three marine actinomycetes strains which were isolated in the Nahoon Beach and tentatively identified as the genera Norcadia, Kibdellosporingium and Saccharopolyspora were investigated in this study against a panel of referenced, environmental and clinical bacterial strains. The ethyl acetate extracts of these marine actinomycetes were screened for activity against 32 bacterial isolates. Out of the 32 organisms, 10 were susceptible to one or all the extracts used. Antibacterial activity was mainly observed against Gram-negative organisms with Minimum inhibitory concentration (MIC) values ranging from 0.078 mg/ml to >10mg/ml. The killing rates of the active extracts were also elucidated using standard procedures. The two extracts NO64 and NO53 showed rapid bactericidal activity against B. pumilus ATCC 14884 and Serratia marcens with a 3Log10 reduction in counts within 6 hours at 3.75 mg/ml and 5 mg/ml respectively. In conclusion, the ethyl acetate extract of these marine actinomycetes strains possess strong bactericidal and bacteriostatic activities against Gram negative organisms and can be therapeutically useful in the treatment of bacterial infections which are mainly caused by Gram negative bacteria. , Thesis (MA) -- Faculty of Science and Agriculture, 2010
- Full Text:
- Date Issued: 2010
- Authors: Koba, Siziwe (https://orcid.org/0000-0002-6761-6403)
- Date: 2010
- Subjects: Actinobacteria , Bacteria , Actinomycetales
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/25811 , vital:64488
- Description: Antibacterial potency of the extracts of the three marine actinomycetes strains which were isolated in the Nahoon Beach and tentatively identified as the genera Norcadia, Kibdellosporingium and Saccharopolyspora were investigated in this study against a panel of referenced, environmental and clinical bacterial strains. The ethyl acetate extracts of these marine actinomycetes were screened for activity against 32 bacterial isolates. Out of the 32 organisms, 10 were susceptible to one or all the extracts used. Antibacterial activity was mainly observed against Gram-negative organisms with Minimum inhibitory concentration (MIC) values ranging from 0.078 mg/ml to >10mg/ml. The killing rates of the active extracts were also elucidated using standard procedures. The two extracts NO64 and NO53 showed rapid bactericidal activity against B. pumilus ATCC 14884 and Serratia marcens with a 3Log10 reduction in counts within 6 hours at 3.75 mg/ml and 5 mg/ml respectively. In conclusion, the ethyl acetate extract of these marine actinomycetes strains possess strong bactericidal and bacteriostatic activities against Gram negative organisms and can be therapeutically useful in the treatment of bacterial infections which are mainly caused by Gram negative bacteria. , Thesis (MA) -- Faculty of Science and Agriculture, 2010
- Full Text:
- Date Issued: 2010
Assessment of antibiotic production by some marine Streptomyces isolated from the Nahoon Beach
- Ogunmwonyi, Isoken Nekpen Henrietta
- Authors: Ogunmwonyi, Isoken Nekpen Henrietta
- Date: 2010
- Subjects: Streptomyces , Actinobacteria , Gram-positive bacteria , Antibiotics , Antibiotics -- Testing , Drug resistance in microorganisms
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11243 , http://hdl.handle.net/10353/264 , Streptomyces , Actinobacteria , Gram-positive bacteria , Antibiotics , Antibiotics -- Testing , Drug resistance in microorganisms
- Description: Rapidly emerging strains of bacteria resistant to most advanced antibiotics have become issues of very important public health concern. Research currently directed towards marine actinomycetes presents a vast potential for new compounds that could be able to safely and effectively target resistant species. In this regard, ten putative Streptomyces strains isolated from the Nahoon beach were selected and assessed for antibiotic production and activity against a wide range of bacteria including reference strains, environmental strain and clinical isolates. The ethyl acetate extracts of the putative Streptomyces isolates showed activities against at least 6 and up to 26 of the 32 test bacteria. Inhibition zones were found to range between 9-32 mm diameters at a concentration of 10 mg/ml. The minimum inhibitory concentrations (MICs) of the crude extracts ranged from 0.039 - 10 mg/ml and the least minimum bactericidal concentration (MBC) demonstrated was 0.625 mg/ml against a reference strain Staphylococcus aureus ATCC 6538. Time kill kinetics of all extracts revealed bacteristatic and bactericidal activities. Average Log reductions in viable cell counts for all the extracts ranged from 0.86 Log10 and 3.99 Log10 cfu/ml after 3 h interaction and 0.01 Log10 and 4.86 Log10 after 6 h interaction at MIC, 2 × MIC, 3 × MIC and 4 × MIC concentrations. Most of the extracts were speedily bactericidal at 3 × MIC and 4 × MIC resulting in over 50 % elimination of most of the test bacteria within 3 h and 6 h interaction. The partial characterization of the crude extracts by IR spectral analysis revealed possibility of terpenoid, long chain fatty acids and secondary amine derivatives compounds in the extracts. It is therefore recommended that further investigation should address the relationship between the structure of the active component of the extracts and the broad spectrum activity, as well as a rapid method for large scale production and purification and whether this group of antibiotics has any application in managing human infectious disease.
- Full Text:
- Date Issued: 2010
- Authors: Ogunmwonyi, Isoken Nekpen Henrietta
- Date: 2010
- Subjects: Streptomyces , Actinobacteria , Gram-positive bacteria , Antibiotics , Antibiotics -- Testing , Drug resistance in microorganisms
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11243 , http://hdl.handle.net/10353/264 , Streptomyces , Actinobacteria , Gram-positive bacteria , Antibiotics , Antibiotics -- Testing , Drug resistance in microorganisms
- Description: Rapidly emerging strains of bacteria resistant to most advanced antibiotics have become issues of very important public health concern. Research currently directed towards marine actinomycetes presents a vast potential for new compounds that could be able to safely and effectively target resistant species. In this regard, ten putative Streptomyces strains isolated from the Nahoon beach were selected and assessed for antibiotic production and activity against a wide range of bacteria including reference strains, environmental strain and clinical isolates. The ethyl acetate extracts of the putative Streptomyces isolates showed activities against at least 6 and up to 26 of the 32 test bacteria. Inhibition zones were found to range between 9-32 mm diameters at a concentration of 10 mg/ml. The minimum inhibitory concentrations (MICs) of the crude extracts ranged from 0.039 - 10 mg/ml and the least minimum bactericidal concentration (MBC) demonstrated was 0.625 mg/ml against a reference strain Staphylococcus aureus ATCC 6538. Time kill kinetics of all extracts revealed bacteristatic and bactericidal activities. Average Log reductions in viable cell counts for all the extracts ranged from 0.86 Log10 and 3.99 Log10 cfu/ml after 3 h interaction and 0.01 Log10 and 4.86 Log10 after 6 h interaction at MIC, 2 × MIC, 3 × MIC and 4 × MIC concentrations. Most of the extracts were speedily bactericidal at 3 × MIC and 4 × MIC resulting in over 50 % elimination of most of the test bacteria within 3 h and 6 h interaction. The partial characterization of the crude extracts by IR spectral analysis revealed possibility of terpenoid, long chain fatty acids and secondary amine derivatives compounds in the extracts. It is therefore recommended that further investigation should address the relationship between the structure of the active component of the extracts and the broad spectrum activity, as well as a rapid method for large scale production and purification and whether this group of antibiotics has any application in managing human infectious disease.
- Full Text:
- Date Issued: 2010
Assessment of bioflocculant production by some marine bacteria isolated from the bottom sediment of Algoa Bay
- Authors: Cosa, Sekelwa
- Date: 2010
- Subjects: Flocculants , Bacteria -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11244 , http://hdl.handle.net/10353/404 , Flocculants , Bacteria -- South Africa -- Algoa Bay
- Description: Several problems concerning the use of conventional synthetic flocculants has necessitated the need for alternative cost effective, safe and efficient bioflocculants from microorganisms inhabiting many environments, particularly those from unusual environments. Hence, this study assessed bioflocculant production by three marine bacteria isolated from the bottom sediment of Algoa Bay in the Eastern Cape Province of South Africa. Analysis of the 16S rDNA sequences led to their identification as Halobacillus sp. Mvuyo, Virgibacillus sp. Rob and Oceanobacillus sp. Pinky. Several factors affecting the production and activity of the bioflocculant(s) were studied. Halobacillus sp. Mvuyo produced bioflocculant optimally with glucose (76%) and ammonium chloride (93%) as sole carbon and nitrogen sources, respectively and at neutral pH and in the presence of Ca2+. On the other hand, Virgibacillus sp. Rob preferred glucose (70.4 %) and iron sulphate (74%) as carbon and nitrogen source respectively; an alkaline pH (12.0) and Fe2+. Oceanobacillus sp. Pinky produced bioflocculant optimally when sucrose (80%) and peptone (72.4 %) were used as carbon and nitrogen source respectively, at neutral pH, and in the presence of Ca2+ cation. The chemical analyses of the partially purified bioflocculants revealed that the bioflocculants produced by Halobacillus sp. Mvuyo and Oceanobacillus sp. Pinky were glycoproteins, while that produced by Virgibacillus sp. Rob was a polysaccharide. We thus conclude that Halobacillus sp. Mvuyo, Virgibacillus sp. Rob and Oceanobacillus sp. Pinky hold promise as producers of new and efficient bioflocculant(s). We recommended development of process conditions for large scale production of the bioflocculants followed by their detailed characterization, as well as pilot scale assessment of the applicability of the purified bioflocculant in water/wastewater treatment and other industrial uses
- Full Text:
- Date Issued: 2010
- Authors: Cosa, Sekelwa
- Date: 2010
- Subjects: Flocculants , Bacteria -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11244 , http://hdl.handle.net/10353/404 , Flocculants , Bacteria -- South Africa -- Algoa Bay
- Description: Several problems concerning the use of conventional synthetic flocculants has necessitated the need for alternative cost effective, safe and efficient bioflocculants from microorganisms inhabiting many environments, particularly those from unusual environments. Hence, this study assessed bioflocculant production by three marine bacteria isolated from the bottom sediment of Algoa Bay in the Eastern Cape Province of South Africa. Analysis of the 16S rDNA sequences led to their identification as Halobacillus sp. Mvuyo, Virgibacillus sp. Rob and Oceanobacillus sp. Pinky. Several factors affecting the production and activity of the bioflocculant(s) were studied. Halobacillus sp. Mvuyo produced bioflocculant optimally with glucose (76%) and ammonium chloride (93%) as sole carbon and nitrogen sources, respectively and at neutral pH and in the presence of Ca2+. On the other hand, Virgibacillus sp. Rob preferred glucose (70.4 %) and iron sulphate (74%) as carbon and nitrogen source respectively; an alkaline pH (12.0) and Fe2+. Oceanobacillus sp. Pinky produced bioflocculant optimally when sucrose (80%) and peptone (72.4 %) were used as carbon and nitrogen source respectively, at neutral pH, and in the presence of Ca2+ cation. The chemical analyses of the partially purified bioflocculants revealed that the bioflocculants produced by Halobacillus sp. Mvuyo and Oceanobacillus sp. Pinky were glycoproteins, while that produced by Virgibacillus sp. Rob was a polysaccharide. We thus conclude that Halobacillus sp. Mvuyo, Virgibacillus sp. Rob and Oceanobacillus sp. Pinky hold promise as producers of new and efficient bioflocculant(s). We recommended development of process conditions for large scale production of the bioflocculants followed by their detailed characterization, as well as pilot scale assessment of the applicability of the purified bioflocculant in water/wastewater treatment and other industrial uses
- Full Text:
- Date Issued: 2010
Assessment of the environmental condition, Ecosystem service provision and sustainability of use of two wetlands in the Kamiesberg uplands:
- Kotze, Donovan C, Malan, H, Ellery, William F N, Samuals, I, Saul, L
- Authors: Kotze, Donovan C , Malan, H , Ellery, William F N , Samuals, I , Saul, L
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157135 , vital:40089 , http://www.wrc.org.za/wp-content/uploads/mdocs/TT439-09 Conservation of Water Ecosystems.pdf
- Description: This report is one of the outputs of the Wetland Health and Importance (WHI) research programme which was funded by the Water Research Commission. The WHI represents Phase II of the National Wetlands Research Programme and was formerly known as “Wetland Health and Integrity”. Phase I, under the leadership of Professor Ellery, resulted in the “WET-Management” series of publications. Phase II, the WHI programme, was broadly aimed at assessing wetland environmental condition and socio-economic importance.
- Full Text:
- Date Issued: 2010
- Authors: Kotze, Donovan C , Malan, H , Ellery, William F N , Samuals, I , Saul, L
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157135 , vital:40089 , http://www.wrc.org.za/wp-content/uploads/mdocs/TT439-09 Conservation of Water Ecosystems.pdf
- Description: This report is one of the outputs of the Wetland Health and Importance (WHI) research programme which was funded by the Water Research Commission. The WHI represents Phase II of the National Wetlands Research Programme and was formerly known as “Wetland Health and Integrity”. Phase I, under the leadership of Professor Ellery, resulted in the “WET-Management” series of publications. Phase II, the WHI programme, was broadly aimed at assessing wetland environmental condition and socio-economic importance.
- Full Text:
- Date Issued: 2010
Assessment of the impact of intergovernmental relations (IGR) on service delivery in the Department of Cooperative Governance and Traditional Affairs (COGTA) in the Eastern Cape province (1994-2009)
- Authors: Feni, Dumisani Wiseman
- Date: 2010
- Subjects: Intergovernmental fiscal relations -- South Africa -- Eastern Cape , Intergovernmental cooperation -- South Africa -- Eastern Cape , Human services -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Admin
- Identifier: vital:11622 , http://hdl.handle.net/10353/529 , Intergovernmental fiscal relations -- South Africa -- Eastern Cape , Intergovernmental cooperation -- South Africa -- Eastern Cape , Human services -- South Africa -- Eastern Cape
- Description: The Constitution Act, 108 of 1996 declares that: 'in the Republic, government is constituted as national, provincial and local spheres of government that are distinctive, interdependent and interrelated". Section 41(1)of the above Constitution further states that there shall be cooperation, mutual trust and good faith between these three spheres. They should inform and consult one another on matters of common interest, co-ordinate their legislation, and adhere to agreed procedures. In addition, it is expected that acts of Parliament should establish structures and institutions to promote and facilitate intergovernmental relations, and provide mechanism and procedures to facilitate settlement of intergovernmental disputes. In view of the above, it is evident that co-operative government can be regarded as one of the cornerstones of the new constitutional dispensation in South Africa and intergovernmental relations can be regarded as practical instrument for ensuring co-operative government in the delivery of services by the three spheres of government. The study therefore seeks to assess the impact of intergovernmental relations on service delivery in the Department of Cooperative Governance and Traditional Affairs in Eastern Cape Province from the year 1994-2009. It also attempts to show the importance of intergovernmental relations to service delivery especially in integrated development planning, co-operation and co-operation and co-ordination of policies and plans. "The assessment of the impact of intergovernmental relations on service delivey in the Department of Co-operative Governance and Traditional Affairs in the Eastern Cape Province (1994-2009)".
- Full Text: false
- Date Issued: 2010
- Authors: Feni, Dumisani Wiseman
- Date: 2010
- Subjects: Intergovernmental fiscal relations -- South Africa -- Eastern Cape , Intergovernmental cooperation -- South Africa -- Eastern Cape , Human services -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Admin
- Identifier: vital:11622 , http://hdl.handle.net/10353/529 , Intergovernmental fiscal relations -- South Africa -- Eastern Cape , Intergovernmental cooperation -- South Africa -- Eastern Cape , Human services -- South Africa -- Eastern Cape
- Description: The Constitution Act, 108 of 1996 declares that: 'in the Republic, government is constituted as national, provincial and local spheres of government that are distinctive, interdependent and interrelated". Section 41(1)of the above Constitution further states that there shall be cooperation, mutual trust and good faith between these three spheres. They should inform and consult one another on matters of common interest, co-ordinate their legislation, and adhere to agreed procedures. In addition, it is expected that acts of Parliament should establish structures and institutions to promote and facilitate intergovernmental relations, and provide mechanism and procedures to facilitate settlement of intergovernmental disputes. In view of the above, it is evident that co-operative government can be regarded as one of the cornerstones of the new constitutional dispensation in South Africa and intergovernmental relations can be regarded as practical instrument for ensuring co-operative government in the delivery of services by the three spheres of government. The study therefore seeks to assess the impact of intergovernmental relations on service delivery in the Department of Cooperative Governance and Traditional Affairs in Eastern Cape Province from the year 1994-2009. It also attempts to show the importance of intergovernmental relations to service delivery especially in integrated development planning, co-operation and co-operation and co-ordination of policies and plans. "The assessment of the impact of intergovernmental relations on service delivey in the Department of Co-operative Governance and Traditional Affairs in the Eastern Cape Province (1994-2009)".
- Full Text: false
- Date Issued: 2010
Assessment of the monkfish Lophius vomerinus resource off Namibia
- Maartens, Lima, Booth, Anthony J
- Authors: Maartens, Lima , Booth, Anthony J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123863 , vital:35509 , https://doi.10.2989/025776101784528926
- Description: Monkfish (Lophius vomerinus and L. vaillanti) constitute a commercially important resource off Namibia. During 1998, the Lophius resource was the fourth most important commercial resource in terms of landed mass (c. 17 000 tons) and the fifth most important commercial resource in terms of export value (U$19.8 million) of the Namibian fishing sector (Ministry of Fisheries and Marine Resources, Namibia, unpublished data). Historically, monkfish constituted an important bycatch in the trawl fishery directed at hake (Merluccius spp.), but due to increasing market demand since the early 1990s, a fishery directed at monkfish and sole (Austroglossus microlepis) has developed. The Namibian Ministry of Fisheries and Marine Resources has identified the need to develop a management plan to ensure the resource’s medium and longterm sustainability (Maartens et al. 1999). Long-term resource management plans include the identification of an assessment model to represent reality so that the implications of managing the resource in future under a range of assumptions about its present status and its future dynamics (Cochrane et al. 1998) can be examined. The aim of this study was, therefore, to assess the status of at least part of the monkfish resource using a length-based cohort assessment (Jones 1979, 1984, Sparre and Venema 1998) and an age structured production model (Punt 1994, Punt and Japp 1994, Booth and Punt 1998).
- Full Text:
- Date Issued: 2010
- Authors: Maartens, Lima , Booth, Anthony J
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123863 , vital:35509 , https://doi.10.2989/025776101784528926
- Description: Monkfish (Lophius vomerinus and L. vaillanti) constitute a commercially important resource off Namibia. During 1998, the Lophius resource was the fourth most important commercial resource in terms of landed mass (c. 17 000 tons) and the fifth most important commercial resource in terms of export value (U$19.8 million) of the Namibian fishing sector (Ministry of Fisheries and Marine Resources, Namibia, unpublished data). Historically, monkfish constituted an important bycatch in the trawl fishery directed at hake (Merluccius spp.), but due to increasing market demand since the early 1990s, a fishery directed at monkfish and sole (Austroglossus microlepis) has developed. The Namibian Ministry of Fisheries and Marine Resources has identified the need to develop a management plan to ensure the resource’s medium and longterm sustainability (Maartens et al. 1999). Long-term resource management plans include the identification of an assessment model to represent reality so that the implications of managing the resource in future under a range of assumptions about its present status and its future dynamics (Cochrane et al. 1998) can be examined. The aim of this study was, therefore, to assess the status of at least part of the monkfish resource using a length-based cohort assessment (Jones 1979, 1984, Sparre and Venema 1998) and an age structured production model (Punt 1994, Punt and Japp 1994, Booth and Punt 1998).
- Full Text:
- Date Issued: 2010
Assessment of the prevalence of virulent Eschericia coli strains in the final effluents of wastewater treatment plants in the Eastern Cape Province of South Africa
- Authors: Osode, Augustina Nwabuje
- Date: 2010
- Subjects: Escherichia coli , Escherichia coli -- Genetics , Effluent quality -- Testing , Water -- Purification , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Whole effluent toxicity testing
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11246 , http://hdl.handle.net/10353/d1001062 , Escherichia coli , Escherichia coli -- Genetics , Effluent quality -- Testing , Water -- Purification , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Whole effluent toxicity testing
- Description: Escherichia coli (E. coli) is a common inhabitant of surface waters in the developed and developing worlds. The majority of E. coli cells present in water are not particularly pathogenic to humans; however, there are some present in small proportion that possess virulence genes that allow them to colonize the digestive tract. Pathogenic E. coli causes acute and chronic diarrheal diseases, especially among children in developing countries and in travelers in these locales. The present study, conducted between August 2007 and July 2008, investigated the prevalence and distribution of virulent E. coli strains as either free or attached cells in the final effluents of three wastewater treatment plants located in the Eastern Cape Province of South Africa and its impact on the physico-chemical quality of the receiving water body. The wastewater treatment plants are located in urban (East Bank Reclamation Works, East London), peri-urban (Dimbaza Sewage Treatment Works) and in rural area (Alice Sewage Treatment Works). The effluent quality of the treatment plants were acceptable with respect to pH (6.9-7.8), temperature (13.8-22.0 °C), dissolved oxygen (DO) (4.9-7.8 mg/L), salinity (0.12-0.17 psu), total dissolved solids (TDS) (119-162 mg/ L) and nitrite concentration (0.1-0.4 mg/l). The other xii physicochemical parameters that did not comply with regulated standards include the following: phosphate (0.1-4.0 mg/L); chemical oxygen demand (COD) (5-211 mg/L); electrical conductivity (EC) (237-325 μS/cm) and Turbidity (7.7-62.7 NTU). Results suggest that eutrophication is intensified in the vicinity of the effluent discharge points, where phosphate and nitrate were found in high concentrations. Presumptive E. coli was isolated from the effluent samples by culture-based methods and confirmed using Polymerase Chain Reaction (PCR) techniques. Antibiogram assay was also carried out using standard in vitro methods on Mueller Hinton agar. The viable counts of presumptive E. coli for the effluent samples associated with 180 μm plankton size ranged between 0 – 4.30 × 101 cfu/ml in Dimbaza, 0 – 3.88 × 101 cfu/ml in Alice and 0 – 8.00 × 101 cfu/ml in East London. In the 60 μm plankton size category E. coli densities ranged between 0 and 4.2 × 101 cfu/ml in Dimbaza, 0 and 2.13 × 101 cfu/ml in Alice and 0 and 8.75 × 101 cfu/ml in East London. Whereas in the 20 μm plankton size category presumptive E. coli density varied from 0 to 5.0 × 101 cfu/ml in Dimbaza, 0 to 3.75 × 101 cfu/ml in Alice and 0 to 9.0 × 101 cfu/ml in East London. The free-living presumptive E. coli density ranged between 0 and 3.13 × 101 cfu/ml in Dimbaza, between 0 and 8.0 × 101 cfu/ml in Alice and between 0 and 9.5 × 101 cfu/ml in East London. Molecular analysis successfully amplified target genes (fliCH7, rfbEO157, ial and aap) which are characteristic of pathogenic E. coli strains. The PCR assays using uidA-specific primer confirmed that a genetic region homologous in size to the E. coli uidA structural gene, including the regulatory region, was present in 3 of the E. coli isolates from Alice, 10 from Dimbaza and 8 from East London. Of the 3 E. coli isolates from Alice, 1 (33.3%) was positive for the fliCH7 genes and 3 was positive for rfbEO157 genes. Out of the 10 isolates from Dimbaza, 4 were xiii positive for fliCH7 genes, 6 were positive for the rfbEO157 genes and 1 was positive for the aap genes; and of the 8 isolates from East London, 1 was positive for fliCH7 genes, 2 were for the rfbEO157 genes, 6 were positive for the ial genes. Antimicrobial susceptibility profile revealed that all of the E. coli strains isolated from the effluent water samples were resistant (R) to linezolid, polymyxin B, penicillin G and sulfamethoxazole. The E. coli isolates from Dimbaza (9/10) and East London (8/8) respectively were resistant to erythromycin. All the isolates were found to be susceptible (S) to amikacin, ceftazidime, ciprofloxacin, colistin sulphate, ceftriaxone, cefotaxime, cefuroxime, ertapenem, gatifloxacin, gentamycin, imidazole, kanamycin, meropenem, moxifloxacin, neomycin, netilmicin, norfloxacin and tobramycin. The findings of this study revealed that the Alice wastewater treatment plant was the most efficient as it produced the final effluent with the least pathogenic E. coli followed by the Dimbaza wastewater treatment plant. In addition, the findings showed that the wastewater treatment plant effluents are a veritable source of pathogenic E. coli in the Eastern Cape Province watershed. We suggest that to maximize public health protection, treated wastewater effluent quality should be diligently monitored pursuant to ensuring high quality of final effluents.
- Full Text:
- Date Issued: 2010
- Authors: Osode, Augustina Nwabuje
- Date: 2010
- Subjects: Escherichia coli , Escherichia coli -- Genetics , Effluent quality -- Testing , Water -- Purification , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Whole effluent toxicity testing
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11246 , http://hdl.handle.net/10353/d1001062 , Escherichia coli , Escherichia coli -- Genetics , Effluent quality -- Testing , Water -- Purification , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Whole effluent toxicity testing
- Description: Escherichia coli (E. coli) is a common inhabitant of surface waters in the developed and developing worlds. The majority of E. coli cells present in water are not particularly pathogenic to humans; however, there are some present in small proportion that possess virulence genes that allow them to colonize the digestive tract. Pathogenic E. coli causes acute and chronic diarrheal diseases, especially among children in developing countries and in travelers in these locales. The present study, conducted between August 2007 and July 2008, investigated the prevalence and distribution of virulent E. coli strains as either free or attached cells in the final effluents of three wastewater treatment plants located in the Eastern Cape Province of South Africa and its impact on the physico-chemical quality of the receiving water body. The wastewater treatment plants are located in urban (East Bank Reclamation Works, East London), peri-urban (Dimbaza Sewage Treatment Works) and in rural area (Alice Sewage Treatment Works). The effluent quality of the treatment plants were acceptable with respect to pH (6.9-7.8), temperature (13.8-22.0 °C), dissolved oxygen (DO) (4.9-7.8 mg/L), salinity (0.12-0.17 psu), total dissolved solids (TDS) (119-162 mg/ L) and nitrite concentration (0.1-0.4 mg/l). The other xii physicochemical parameters that did not comply with regulated standards include the following: phosphate (0.1-4.0 mg/L); chemical oxygen demand (COD) (5-211 mg/L); electrical conductivity (EC) (237-325 μS/cm) and Turbidity (7.7-62.7 NTU). Results suggest that eutrophication is intensified in the vicinity of the effluent discharge points, where phosphate and nitrate were found in high concentrations. Presumptive E. coli was isolated from the effluent samples by culture-based methods and confirmed using Polymerase Chain Reaction (PCR) techniques. Antibiogram assay was also carried out using standard in vitro methods on Mueller Hinton agar. The viable counts of presumptive E. coli for the effluent samples associated with 180 μm plankton size ranged between 0 – 4.30 × 101 cfu/ml in Dimbaza, 0 – 3.88 × 101 cfu/ml in Alice and 0 – 8.00 × 101 cfu/ml in East London. In the 60 μm plankton size category E. coli densities ranged between 0 and 4.2 × 101 cfu/ml in Dimbaza, 0 and 2.13 × 101 cfu/ml in Alice and 0 and 8.75 × 101 cfu/ml in East London. Whereas in the 20 μm plankton size category presumptive E. coli density varied from 0 to 5.0 × 101 cfu/ml in Dimbaza, 0 to 3.75 × 101 cfu/ml in Alice and 0 to 9.0 × 101 cfu/ml in East London. The free-living presumptive E. coli density ranged between 0 and 3.13 × 101 cfu/ml in Dimbaza, between 0 and 8.0 × 101 cfu/ml in Alice and between 0 and 9.5 × 101 cfu/ml in East London. Molecular analysis successfully amplified target genes (fliCH7, rfbEO157, ial and aap) which are characteristic of pathogenic E. coli strains. The PCR assays using uidA-specific primer confirmed that a genetic region homologous in size to the E. coli uidA structural gene, including the regulatory region, was present in 3 of the E. coli isolates from Alice, 10 from Dimbaza and 8 from East London. Of the 3 E. coli isolates from Alice, 1 (33.3%) was positive for the fliCH7 genes and 3 was positive for rfbEO157 genes. Out of the 10 isolates from Dimbaza, 4 were xiii positive for fliCH7 genes, 6 were positive for the rfbEO157 genes and 1 was positive for the aap genes; and of the 8 isolates from East London, 1 was positive for fliCH7 genes, 2 were for the rfbEO157 genes, 6 were positive for the ial genes. Antimicrobial susceptibility profile revealed that all of the E. coli strains isolated from the effluent water samples were resistant (R) to linezolid, polymyxin B, penicillin G and sulfamethoxazole. The E. coli isolates from Dimbaza (9/10) and East London (8/8) respectively were resistant to erythromycin. All the isolates were found to be susceptible (S) to amikacin, ceftazidime, ciprofloxacin, colistin sulphate, ceftriaxone, cefotaxime, cefuroxime, ertapenem, gatifloxacin, gentamycin, imidazole, kanamycin, meropenem, moxifloxacin, neomycin, netilmicin, norfloxacin and tobramycin. The findings of this study revealed that the Alice wastewater treatment plant was the most efficient as it produced the final effluent with the least pathogenic E. coli followed by the Dimbaza wastewater treatment plant. In addition, the findings showed that the wastewater treatment plant effluents are a veritable source of pathogenic E. coli in the Eastern Cape Province watershed. We suggest that to maximize public health protection, treated wastewater effluent quality should be diligently monitored pursuant to ensuring high quality of final effluents.
- Full Text:
- Date Issued: 2010
at the conference in munich
- Authors: Krueger, Anton
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229774 , vital:49709 , xlink:href="https://hdl.handle.net/10520/EJC47821"
- Full Text:
- Date Issued: 2010
- Authors: Krueger, Anton
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229774 , vital:49709 , xlink:href="https://hdl.handle.net/10520/EJC47821"
- Full Text:
- Date Issued: 2010
Attitudes towards hunting amongst the economically active public in Port Elizabeth
- Coetzer, Wentzel Christoffel
- Authors: Coetzer, Wentzel Christoffel
- Date: 2010
- Subjects: Hunting -- South Africa -- Port Elizabeth , Wildlife management -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10746 , http://hdl.handle.net/10948/1507 , Hunting -- South Africa -- Port Elizabeth , Wildlife management -- South Africa -- Port Elizabeth
- Description: Wildlife ranching is recognized as one of the important agricultural industries in South Africa, with hunting being the primary segment of the game industry. Hunting is an essential part of wildlife management and it contributes significantly to the conservation of biodiversity and to the economy. Despite this, the social acceptability of hunting is often questioned and negative attitudes towards hunting within the larger society may become a potential threat to the hunting industry. This may jeopardize the effective management of game and have a negative impact on conservation and the economy. This study is an empirical investigation of the attitudes of the economically active public in Port Elizabeth towards hunting. The objectives of this study are to investigate the nature and extent of the public's attitudes towards hunting, as well as to identify factors influencing the public's attitudes towards hunting. The study commenced with the establishment of a theoretical framework, based on a literature study on the psychology of human perceptions and attitudes towards hunting. The theoretical framework was then used to develop the empirical component of the study. A survey was conducted amongst a statistically representative sample of the economically active public in Port Elizabeth during 2009. The data was collected by means of personal interviews and self-administered questionnaires were used as the survey instrument. The study found that the economically active public in Port Elizabeth generally holds favourable attitudes towards hunting, with only a small proportion of the population wanting to ban hunting. The belief that hunting endangers wildlife was the most prominent reason for opposing hunting. Negative attitudes towards hunting were largely based on incorrect beliefs regarding hunting. The extent of a person's knowledge of hunting and exposure to hunting, as well as a person's social ties had a significant influence on their attitudes towards hunting.
- Full Text:
- Date Issued: 2010
- Authors: Coetzer, Wentzel Christoffel
- Date: 2010
- Subjects: Hunting -- South Africa -- Port Elizabeth , Wildlife management -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10746 , http://hdl.handle.net/10948/1507 , Hunting -- South Africa -- Port Elizabeth , Wildlife management -- South Africa -- Port Elizabeth
- Description: Wildlife ranching is recognized as one of the important agricultural industries in South Africa, with hunting being the primary segment of the game industry. Hunting is an essential part of wildlife management and it contributes significantly to the conservation of biodiversity and to the economy. Despite this, the social acceptability of hunting is often questioned and negative attitudes towards hunting within the larger society may become a potential threat to the hunting industry. This may jeopardize the effective management of game and have a negative impact on conservation and the economy. This study is an empirical investigation of the attitudes of the economically active public in Port Elizabeth towards hunting. The objectives of this study are to investigate the nature and extent of the public's attitudes towards hunting, as well as to identify factors influencing the public's attitudes towards hunting. The study commenced with the establishment of a theoretical framework, based on a literature study on the psychology of human perceptions and attitudes towards hunting. The theoretical framework was then used to develop the empirical component of the study. A survey was conducted amongst a statistically representative sample of the economically active public in Port Elizabeth during 2009. The data was collected by means of personal interviews and self-administered questionnaires were used as the survey instrument. The study found that the economically active public in Port Elizabeth generally holds favourable attitudes towards hunting, with only a small proportion of the population wanting to ban hunting. The belief that hunting endangers wildlife was the most prominent reason for opposing hunting. Negative attitudes towards hunting were largely based on incorrect beliefs regarding hunting. The extent of a person's knowledge of hunting and exposure to hunting, as well as a person's social ties had a significant influence on their attitudes towards hunting.
- Full Text:
- Date Issued: 2010
Attracting and retaining customers in South Adrica's banking sector
- Authors: Anani, Ajibola Plakunle
- Date: 2010
- Subjects: Banks and banking -- Customer services -- South Africa -- Port Elizabeth , Customer relations -- Management , Consumer satisfaction -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8575 , http://hdl.handle.net/10948/1532 , Banks and banking -- Customer services -- South Africa -- Port Elizabeth , Customer relations -- Management , Consumer satisfaction -- South Africa -- Port Elizabeth
- Description: The business environment and the economy of the society today are continuously witnessing the impact of globalisation. Telecommunication advancement and transportation has greatly made the impact of globalisation to be felt. Globalisation though argued to have its merits and its demerits have resulted in fierce competition amongst businesses. The banking industry is not isolated from these competitions. Any business wishing to survive and stay profitable in the recent world must be able to compete in the global economy. Hence, for any bank to sustain itself and remain profitable it must be able to withstand the competition in the environment it operates. To be able to compete in the banking industry means delivering better services to customers than competitors. This study presents how the South African banks can satisfy their customers and remain profitable in the face of competition. The South African banking industry consists of local and foreign banks and these banks compete for customers in the environment in which they are located. Increase in different branches by different banks has made the competition even fierce. In other to suggest recommendations for the South African banks to satisfy their customers and become profitable, the researcher identified some problem areas that need to be improved upon. These include customer loyalty, relationship banking and electronic banking. These variables were researched to understand how they affect the banks and the customers and where tested using both a qualitative and a quantitative analysis to ascertain if the customers were satisfied with the banks‟ approach of managing these variables. The results indicated that the customers were satisfied to a lesser extent. Any bank wishing to satisfy its customers and remain profitable in other to compete in the industry needs to satisfy the customer to a large extent. Therefore, recommendations where suggested based on the empirical results to help improve the banking industry‟s ways of attracting and retaining customers. The former will lead to customer satisfaction which again will lead to increased profitability.
- Full Text:
- Date Issued: 2010
- Authors: Anani, Ajibola Plakunle
- Date: 2010
- Subjects: Banks and banking -- Customer services -- South Africa -- Port Elizabeth , Customer relations -- Management , Consumer satisfaction -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8575 , http://hdl.handle.net/10948/1532 , Banks and banking -- Customer services -- South Africa -- Port Elizabeth , Customer relations -- Management , Consumer satisfaction -- South Africa -- Port Elizabeth
- Description: The business environment and the economy of the society today are continuously witnessing the impact of globalisation. Telecommunication advancement and transportation has greatly made the impact of globalisation to be felt. Globalisation though argued to have its merits and its demerits have resulted in fierce competition amongst businesses. The banking industry is not isolated from these competitions. Any business wishing to survive and stay profitable in the recent world must be able to compete in the global economy. Hence, for any bank to sustain itself and remain profitable it must be able to withstand the competition in the environment it operates. To be able to compete in the banking industry means delivering better services to customers than competitors. This study presents how the South African banks can satisfy their customers and remain profitable in the face of competition. The South African banking industry consists of local and foreign banks and these banks compete for customers in the environment in which they are located. Increase in different branches by different banks has made the competition even fierce. In other to suggest recommendations for the South African banks to satisfy their customers and become profitable, the researcher identified some problem areas that need to be improved upon. These include customer loyalty, relationship banking and electronic banking. These variables were researched to understand how they affect the banks and the customers and where tested using both a qualitative and a quantitative analysis to ascertain if the customers were satisfied with the banks‟ approach of managing these variables. The results indicated that the customers were satisfied to a lesser extent. Any bank wishing to satisfy its customers and remain profitable in other to compete in the industry needs to satisfy the customer to a large extent. Therefore, recommendations where suggested based on the empirical results to help improve the banking industry‟s ways of attracting and retaining customers. The former will lead to customer satisfaction which again will lead to increased profitability.
- Full Text:
- Date Issued: 2010
Attraction and retention of non-family business employees
- Authors: Van Zyl, Jacques
- Date: 2010
- Subjects: Family-owned business enterprises , Employee retention
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8653 , http://hdl.handle.net/10948/1365 , Family-owned business enterprises , Employee retention
- Description: The purpose of this research treatise was to identify specific aspects related to employees in a non-family owned business that can be adopted by family owned businesses in order to attract, attain and motivate non-family employees. The focus of the researched aspect was based on seven categories of business management, namely; governance, policies and procedures, direction and planning, leadership, employee development, rewards and other general related characteristics. The research commenced with a literature review, which centered on background information pertaining to family owned businesses and specific aspects related to organisation and management thereof. It was assessed that very few completed research papers exit that addressed the topic as indicated above. The research focussed on a medium sized, non-family owned business within the consulting engineering industry. The physical research consisted of a questionnaire distributed to all of the employees of the particular firm. The questionnaire was made up of two sections. The first was a typical Likert scale type and the second, open ended questions. The questions of both question sets were categorised in specific business control and management topics, namely: - Governance; - Policies and procedures; - Direction and planning; - Leadership; - Employee development; - Rewards; and, - General aspects. The primary objective of this study was to identify and explore the factors that are regarded to be important by unrelated employees in work environment, specifically focusing on attaining, retaining and motivating aspects. The study found that the average employee prefers to have desire for formal management structures and see succession planning not only as an important sustainable business strategy, but also as an underlying motivation principle. Also identified were the partialities towards formal employee management systems, employee development, and the value of monetary rewards.
- Full Text:
- Date Issued: 2010
- Authors: Van Zyl, Jacques
- Date: 2010
- Subjects: Family-owned business enterprises , Employee retention
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8653 , http://hdl.handle.net/10948/1365 , Family-owned business enterprises , Employee retention
- Description: The purpose of this research treatise was to identify specific aspects related to employees in a non-family owned business that can be adopted by family owned businesses in order to attract, attain and motivate non-family employees. The focus of the researched aspect was based on seven categories of business management, namely; governance, policies and procedures, direction and planning, leadership, employee development, rewards and other general related characteristics. The research commenced with a literature review, which centered on background information pertaining to family owned businesses and specific aspects related to organisation and management thereof. It was assessed that very few completed research papers exit that addressed the topic as indicated above. The research focussed on a medium sized, non-family owned business within the consulting engineering industry. The physical research consisted of a questionnaire distributed to all of the employees of the particular firm. The questionnaire was made up of two sections. The first was a typical Likert scale type and the second, open ended questions. The questions of both question sets were categorised in specific business control and management topics, namely: - Governance; - Policies and procedures; - Direction and planning; - Leadership; - Employee development; - Rewards; and, - General aspects. The primary objective of this study was to identify and explore the factors that are regarded to be important by unrelated employees in work environment, specifically focusing on attaining, retaining and motivating aspects. The study found that the average employee prefers to have desire for formal management structures and see succession planning not only as an important sustainable business strategy, but also as an underlying motivation principle. Also identified were the partialities towards formal employee management systems, employee development, and the value of monetary rewards.
- Full Text:
- Date Issued: 2010
Audit of community pharmacy activities
- Authors: Blignault, Suzette Martha
- Date: 2010
- Subjects: Pharmacy , Community health services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10130 , http://hdl.handle.net/10948/1533 , Pharmacy , Community health services
- Description: In South Africa the pharmacy profession has experienced a number of changes around the turn of the century such as the introduction of the National Drug Policy (NDP), pharmacy ownership and price regulation. With this the role and earnings of the pharmacy profession, as well as to what extent the pharmacist adds value to the profession and society, are being questioned. Community pharmacists are thus faced with the challenge to prove that the value that they add to society is meaningful. Therefore, the aim of the study was to document community pharmacy availability and activities in South Africa and based on this to quantify the perceived value that the community pharmacist adds to society through the delivery of pharmaceutical services and pharmaceutical care. In order to determine the pharmacist’s true value added two surveys were conducted in 2006; an original pharmacist survey and a general public survey. The results obtained were verified by a follow–up pharmacist survey in 2009 to confirm or reject the results obtained in the original survey. The study was representative of both the community pharmacies and the general public in South Africa and was primarily quantitative in design and analysis. More than half of the responding pharmacies (63.16%) were open seven days a week. The average hours of service per day ranged from 10 hours (Monday to Friday) through to 6.45 hours on Saturdays and 3 hours on Sundays. Pharmacists continuously upgraded their professional knowledge. More than three quarters of pharmacies had the necessary equipment available to perform the services investigated in the study. The general public was not aware of all the services provided by pharmacists and as a result, depending on the service, many people did not make use of these services. The general public that made use of services delivered by community pharmacies mainly perceived the services delivered to be of good quality. The main barrier to practicing pharmaceutical care was indicated by pharmacists as not receiving payment for the advice given followed by pharmaceutical care being time consuming, and that there was not enough time to talk to patients. The general public indicated that they found it difficult to ask questions in pharmacies because other patients could hear what was discussed, or other patients had to wait longer if they asked something, and pharmacy staff being too busy. The results of the original pharmacist and the general public survey were confirmed by the results of the follow-up survey with the exception of dispensing prescription medicine (8 minutes 28 seconds), OTC medicine (7 minutes 23 seconds), counselling of prescription medicine (8 minutes 51 seconds) and OTC medicine (8 minutes) which on average took longer to conduct than in the previous analysis. The study highlighted the value added to the wellness and quality of life of the community of South Africa through the delivery of pharmaceutical care and pharmaceutical services by community pharmacy staff, and proved that pharmacists are committed to the provision of pharmaceutical care and pharmaceutical services.
- Full Text:
- Date Issued: 2010
- Authors: Blignault, Suzette Martha
- Date: 2010
- Subjects: Pharmacy , Community health services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10130 , http://hdl.handle.net/10948/1533 , Pharmacy , Community health services
- Description: In South Africa the pharmacy profession has experienced a number of changes around the turn of the century such as the introduction of the National Drug Policy (NDP), pharmacy ownership and price regulation. With this the role and earnings of the pharmacy profession, as well as to what extent the pharmacist adds value to the profession and society, are being questioned. Community pharmacists are thus faced with the challenge to prove that the value that they add to society is meaningful. Therefore, the aim of the study was to document community pharmacy availability and activities in South Africa and based on this to quantify the perceived value that the community pharmacist adds to society through the delivery of pharmaceutical services and pharmaceutical care. In order to determine the pharmacist’s true value added two surveys were conducted in 2006; an original pharmacist survey and a general public survey. The results obtained were verified by a follow–up pharmacist survey in 2009 to confirm or reject the results obtained in the original survey. The study was representative of both the community pharmacies and the general public in South Africa and was primarily quantitative in design and analysis. More than half of the responding pharmacies (63.16%) were open seven days a week. The average hours of service per day ranged from 10 hours (Monday to Friday) through to 6.45 hours on Saturdays and 3 hours on Sundays. Pharmacists continuously upgraded their professional knowledge. More than three quarters of pharmacies had the necessary equipment available to perform the services investigated in the study. The general public was not aware of all the services provided by pharmacists and as a result, depending on the service, many people did not make use of these services. The general public that made use of services delivered by community pharmacies mainly perceived the services delivered to be of good quality. The main barrier to practicing pharmaceutical care was indicated by pharmacists as not receiving payment for the advice given followed by pharmaceutical care being time consuming, and that there was not enough time to talk to patients. The general public indicated that they found it difficult to ask questions in pharmacies because other patients could hear what was discussed, or other patients had to wait longer if they asked something, and pharmacy staff being too busy. The results of the original pharmacist and the general public survey were confirmed by the results of the follow-up survey with the exception of dispensing prescription medicine (8 minutes 28 seconds), OTC medicine (7 minutes 23 seconds), counselling of prescription medicine (8 minutes 51 seconds) and OTC medicine (8 minutes) which on average took longer to conduct than in the previous analysis. The study highlighted the value added to the wellness and quality of life of the community of South Africa through the delivery of pharmaceutical care and pharmaceutical services by community pharmacy staff, and proved that pharmacists are committed to the provision of pharmaceutical care and pharmaceutical services.
- Full Text:
- Date Issued: 2010
Bandwidth management and monitoring for community networks
- Irwin, Barry V W, Siebörger, Ingrid, Wells, Daniel
- Authors: Irwin, Barry V W , Siebörger, Ingrid , Wells, Daniel
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428040 , vital:72482 , https://www.researchgate.net/profile/Ingrid-Sieboerger/publication/265121154_Bandwidth_management_and_monitoring_for_community_networks/links/5e538b85458515072db7a686/Bandwidth-management-and-monitoring-for-community-networks.pdf
- Description: This paper describes a custom-built system to replace existing routing solutions within an identified community network. The community net-work in question shares a VSAT Internet connection to provide Internet access to a number of schools and their surrounding communities. This connection provides a limited resource which needs to be managed in order to ensure equitable use by members of the community. The community network originally lacked any form of bandwidth manage-ment or monitoring which often resulted in unfair use and abuse. The solution implemented is based on a client-server architecture. The Community Access Points (CAPs) are the client components which are located at each school; providing the computers and servers with ac-cess to the rest of the community network and the Internet. These nodes also perform a number of monitoring tasks for the computers at the schools. The server component is the Access Concentrator (AC) and connects the CAPs together using encrypted and authenticated PPPoE tunnels. The AC performs several additional monitoring func-tions, both on the individual links and on the upstream Internet connec-tion. The AC provides a means of effectively and centrally managing and allocating Internet bandwidth between the schools. The system that was developed has a number of features, including Quality of Service adjustments limiting network usage and fairly billing each school for their Internet use. The system provides an effective means for sharing bandwidth between users in a community network.
- Full Text:
- Date Issued: 2010
- Authors: Irwin, Barry V W , Siebörger, Ingrid , Wells, Daniel
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428040 , vital:72482 , https://www.researchgate.net/profile/Ingrid-Sieboerger/publication/265121154_Bandwidth_management_and_monitoring_for_community_networks/links/5e538b85458515072db7a686/Bandwidth-management-and-monitoring-for-community-networks.pdf
- Description: This paper describes a custom-built system to replace existing routing solutions within an identified community network. The community net-work in question shares a VSAT Internet connection to provide Internet access to a number of schools and their surrounding communities. This connection provides a limited resource which needs to be managed in order to ensure equitable use by members of the community. The community network originally lacked any form of bandwidth manage-ment or monitoring which often resulted in unfair use and abuse. The solution implemented is based on a client-server architecture. The Community Access Points (CAPs) are the client components which are located at each school; providing the computers and servers with ac-cess to the rest of the community network and the Internet. These nodes also perform a number of monitoring tasks for the computers at the schools. The server component is the Access Concentrator (AC) and connects the CAPs together using encrypted and authenticated PPPoE tunnels. The AC performs several additional monitoring func-tions, both on the individual links and on the upstream Internet connec-tion. The AC provides a means of effectively and centrally managing and allocating Internet bandwidth between the schools. The system that was developed has a number of features, including Quality of Service adjustments limiting network usage and fairly billing each school for their Internet use. The system provides an effective means for sharing bandwidth between users in a community network.
- Full Text:
- Date Issued: 2010
Barriers to accessing water services in the Motherwell township
- Authors: Mbashe, Mfundo
- Date: 2010
- Subjects: Water-supply -- Developing countries , Water resources development -- Developing countries , Water supply -- South Africa -- Eastern Cape -- Management , Water supply -- South Africa -- Eastern Cape -- Cost effectiveness
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9039 , http://hdl.handle.net/10948/1190 , Water-supply -- Developing countries , Water resources development -- Developing countries , Water supply -- South Africa -- Eastern Cape -- Management , Water supply -- South Africa -- Eastern Cape -- Cost effectiveness
- Description: Access to adequate water and sanitation services in South Africa still remain a pipe dream for the millions who are trapped at the bottom of the class structures in the country. The poverty stricken communities living in Townships such as Motherwell, everyday long for water services infrastructure to be built in their places of residence. The costs of accessing water services also becomes a setback for many consumers in the area, this is after the infrastructure has been installed in their areas. The high unemployment rate plays an enormous role in many consumers not affording water services. Bureaucracy between the government department of Housing and the NMMBM also impedes delivery of water services for without formal housing, water and sanitation is impossible to be accessed within the households. The study revealed from the semi-structured interviews which were held with Mayoral Council official and Ward Councillors as well as with members of the communities NU 12 and 29 that access to adequate water services was not successful and satisfactory. The findings of the research demonstrate that the Municipality has a problem with retaining staff members in the portfolio of Infrastructure, Engineering, Electricity and Energy, which is the responsible department for providing water and sanitation services to the local inhabitants. This study was conducted from April 2009 to November 2009 and it was aimed at finding the Barriers to accessing water services in the Motherwell Township.
- Full Text:
- Date Issued: 2010
- Authors: Mbashe, Mfundo
- Date: 2010
- Subjects: Water-supply -- Developing countries , Water resources development -- Developing countries , Water supply -- South Africa -- Eastern Cape -- Management , Water supply -- South Africa -- Eastern Cape -- Cost effectiveness
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9039 , http://hdl.handle.net/10948/1190 , Water-supply -- Developing countries , Water resources development -- Developing countries , Water supply -- South Africa -- Eastern Cape -- Management , Water supply -- South Africa -- Eastern Cape -- Cost effectiveness
- Description: Access to adequate water and sanitation services in South Africa still remain a pipe dream for the millions who are trapped at the bottom of the class structures in the country. The poverty stricken communities living in Townships such as Motherwell, everyday long for water services infrastructure to be built in their places of residence. The costs of accessing water services also becomes a setback for many consumers in the area, this is after the infrastructure has been installed in their areas. The high unemployment rate plays an enormous role in many consumers not affording water services. Bureaucracy between the government department of Housing and the NMMBM also impedes delivery of water services for without formal housing, water and sanitation is impossible to be accessed within the households. The study revealed from the semi-structured interviews which were held with Mayoral Council official and Ward Councillors as well as with members of the communities NU 12 and 29 that access to adequate water services was not successful and satisfactory. The findings of the research demonstrate that the Municipality has a problem with retaining staff members in the portfolio of Infrastructure, Engineering, Electricity and Energy, which is the responsible department for providing water and sanitation services to the local inhabitants. This study was conducted from April 2009 to November 2009 and it was aimed at finding the Barriers to accessing water services in the Motherwell Township.
- Full Text:
- Date Issued: 2010
Becoming a business journalist in Malawi: a case study of The Daily Times and The Nation newspapers
- Authors: Manjawira, Ellard Spencer
- Date: 2010 , 2013-07-17
- Subjects: Journalists -- Malawi Journalism -- Study and teaching -- Malawi Journalists -- Training of -- Malawi Journalists -- Education -- Malawi
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3506 , http://hdl.handle.net/10962/d1007440
- Description: In the past few decades, the proportion of business news compared to general news has increased tremendously across all media platforms in Africa. While the critical role played by business journalism is recognised, little is known about the people who write and report such news. Most studies on business reporting have tended to focus on analysing the content of business news, rather than the specific processes through which business journalists are socialized and trained. The findings of this study are drawn mainly from in-depth interviews with business reporters and editors at two leading newspapers in Malawi, The Daily Times and The Nation. Three major findings emerge trom the study data. First, business journalists vary in their educational and professional backgrounds, as well as the reasons for working on this beat. Second, the majority of them have no prerequisite formal education and training in business journalism and, therefore, have little knowledge and skills about what constitute good business journalism. Third, professionalism in the sub-field is constrained by a host of factors, influence of advertisers being the critical one. The study recommends that business reporting become an integral component of journalism education and training programmes to adequately prepare future generations of business journalists. In addition there is need for media houses to devise strategies to counter obstacles that business journalists face for them to effectively contribute to political economy debate. , KMBT_363
- Full Text:
- Date Issued: 2010
- Authors: Manjawira, Ellard Spencer
- Date: 2010 , 2013-07-17
- Subjects: Journalists -- Malawi Journalism -- Study and teaching -- Malawi Journalists -- Training of -- Malawi Journalists -- Education -- Malawi
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3506 , http://hdl.handle.net/10962/d1007440
- Description: In the past few decades, the proportion of business news compared to general news has increased tremendously across all media platforms in Africa. While the critical role played by business journalism is recognised, little is known about the people who write and report such news. Most studies on business reporting have tended to focus on analysing the content of business news, rather than the specific processes through which business journalists are socialized and trained. The findings of this study are drawn mainly from in-depth interviews with business reporters and editors at two leading newspapers in Malawi, The Daily Times and The Nation. Three major findings emerge trom the study data. First, business journalists vary in their educational and professional backgrounds, as well as the reasons for working on this beat. Second, the majority of them have no prerequisite formal education and training in business journalism and, therefore, have little knowledge and skills about what constitute good business journalism. Third, professionalism in the sub-field is constrained by a host of factors, influence of advertisers being the critical one. The study recommends that business reporting become an integral component of journalism education and training programmes to adequately prepare future generations of business journalists. In addition there is need for media houses to devise strategies to counter obstacles that business journalists face for them to effectively contribute to political economy debate. , KMBT_363
- Full Text:
- Date Issued: 2010
Beta-N-methylamino-L-alanine in South African fresh water cyanobacteria : incidence, prevalence, ecotoxicological considerations and human exposure risk
- Authors: Esterhuizen-Londt, Maranda
- Date: 2010
- Subjects: Cyanobacteria , Bioaccumulation , Chromatographic analysis , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10306 , http://hdl.handle.net/10948/1473 , Cyanobacteria , Bioaccumulation , Chromatographic analysis , Neurotoxic agents
- Description: β-N-methylamino-L-alanine (BMAA) is a non-proteinogenic amino acid associated with human neurodegenerative disease. Due to the cosmopolitan nature of cyanobacteria, detection of BMAA in cyanobacteria has caused concerns about human exposure risk. This study was therefore based on the hypothesis that BMAA poses a health risk to humans either by direct ingestion or by indirect exposure to BMAA from a cyanobacterial source via a freshwater food chain. A validated gas chromatography-mass spectrometry (GC-MS) BMAA analysis method and a confirmatory liquid chromatography-mass spectrometry (LC-MS) method, with improved sensitivity, were developed in addition to a LC-MS/MS method for analyte confirmation. These methods were used to quantify BMAA in South African cyanobacteria, isolated from various potable water reservoirs. The majority of the isolates tested, contained BMAA. Possible human exposure by direct consumption of BMAA released from cyanobacterial blooms was investigated by the development of a robust solid phase extraction (SPE) method used for BMAA concentration and quantification in raw and treated tap water. Despite the use of the SPE method that facilitated the concentration of BMAA from large quantities of water, no free dissolved BMAA was detected in raw or processed fresh water. The fate of exogenous BMAA was therefore investigated firstly by evaluating the efficacy of standard water treatment processes employed in South Africa and secondly by investigating the possibility of BMAA bioaccumulation and biomagnification in aquatic food chains. Standard water treatment processes proved highly efficient at removing free dissolved BMAA, explaining the absence of BMAA in treated tap water. However, the cause of the BMAA absence in raw potable water remained unknown. Uptake of BMAA by model aquatic organisms was investigated in controlled experiments. BMAA uptake was documented in both Ceratophyllum demersum and Daphnia magna, however, BMAA-protein association and biomagnification were not observed in D. magna. BMAA had an inhibitory effect on the oxidative stress enzyme acitivties of both organisms tested (as well as human S9 extracts), resulting in accumulation of detrimental reactive oxygen species (ROS) in the cells. Exposure of crop plants to BMAA in controlled experiments resulted in BMAA uptake, protein association, and subsequent inhibition of the antioxidative enzyme activities. However, BMAA was detected in neither free nor protein-associated form in natural crop plants irrigated with known BMAA-containing bloom water. Post-mortem liver samples of Clarias gariepinus (Catfish) and Crocodylus niloticus (Crocodile), from a natural fresh water ecosystem that experienced frequent cyanobacterial blooms, contained both free and protein-associated BMAA. Higher BMAA concentrations were found in crocodile liver samples compared to fish liver samples, strongly suggesting biomagnification from one trophic level to the next. BMAA concentrations corresponded to crocodile age. This is the first report of bioaccumulation and biomagnification in two trophic levels in a fresh water ecosystem. These findings strongly suggest possible human exposure via aquatic food chains of cyanobacterial origin. Direct BMAA exposure via drinking water is not plausible due to the efficiency of standard water treatment processes to remove BMAA. The use of raw water for agricultural and recreational use, however, remains a problem. The development of management strategies as well as daily tolerable levels for BMAA is urgently required.
- Full Text:
- Date Issued: 2010
- Authors: Esterhuizen-Londt, Maranda
- Date: 2010
- Subjects: Cyanobacteria , Bioaccumulation , Chromatographic analysis , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10306 , http://hdl.handle.net/10948/1473 , Cyanobacteria , Bioaccumulation , Chromatographic analysis , Neurotoxic agents
- Description: β-N-methylamino-L-alanine (BMAA) is a non-proteinogenic amino acid associated with human neurodegenerative disease. Due to the cosmopolitan nature of cyanobacteria, detection of BMAA in cyanobacteria has caused concerns about human exposure risk. This study was therefore based on the hypothesis that BMAA poses a health risk to humans either by direct ingestion or by indirect exposure to BMAA from a cyanobacterial source via a freshwater food chain. A validated gas chromatography-mass spectrometry (GC-MS) BMAA analysis method and a confirmatory liquid chromatography-mass spectrometry (LC-MS) method, with improved sensitivity, were developed in addition to a LC-MS/MS method for analyte confirmation. These methods were used to quantify BMAA in South African cyanobacteria, isolated from various potable water reservoirs. The majority of the isolates tested, contained BMAA. Possible human exposure by direct consumption of BMAA released from cyanobacterial blooms was investigated by the development of a robust solid phase extraction (SPE) method used for BMAA concentration and quantification in raw and treated tap water. Despite the use of the SPE method that facilitated the concentration of BMAA from large quantities of water, no free dissolved BMAA was detected in raw or processed fresh water. The fate of exogenous BMAA was therefore investigated firstly by evaluating the efficacy of standard water treatment processes employed in South Africa and secondly by investigating the possibility of BMAA bioaccumulation and biomagnification in aquatic food chains. Standard water treatment processes proved highly efficient at removing free dissolved BMAA, explaining the absence of BMAA in treated tap water. However, the cause of the BMAA absence in raw potable water remained unknown. Uptake of BMAA by model aquatic organisms was investigated in controlled experiments. BMAA uptake was documented in both Ceratophyllum demersum and Daphnia magna, however, BMAA-protein association and biomagnification were not observed in D. magna. BMAA had an inhibitory effect on the oxidative stress enzyme acitivties of both organisms tested (as well as human S9 extracts), resulting in accumulation of detrimental reactive oxygen species (ROS) in the cells. Exposure of crop plants to BMAA in controlled experiments resulted in BMAA uptake, protein association, and subsequent inhibition of the antioxidative enzyme activities. However, BMAA was detected in neither free nor protein-associated form in natural crop plants irrigated with known BMAA-containing bloom water. Post-mortem liver samples of Clarias gariepinus (Catfish) and Crocodylus niloticus (Crocodile), from a natural fresh water ecosystem that experienced frequent cyanobacterial blooms, contained both free and protein-associated BMAA. Higher BMAA concentrations were found in crocodile liver samples compared to fish liver samples, strongly suggesting biomagnification from one trophic level to the next. BMAA concentrations corresponded to crocodile age. This is the first report of bioaccumulation and biomagnification in two trophic levels in a fresh water ecosystem. These findings strongly suggest possible human exposure via aquatic food chains of cyanobacterial origin. Direct BMAA exposure via drinking water is not plausible due to the efficiency of standard water treatment processes to remove BMAA. The use of raw water for agricultural and recreational use, however, remains a problem. The development of management strategies as well as daily tolerable levels for BMAA is urgently required.
- Full Text:
- Date Issued: 2010
Beyond Afrocentricism and Orientalism contemporary representations of transnational identities in the works of Nontsikelelo "Lolo" Veleko and Tracy Payne
- Authors: Pycroft, Hayley
- Date: 2010
- Subjects: Veleko, Nontsikelelo -- Criticism and interpretation Payne, Tracy, 1965- -- Criticism and interpretation Afrocentrism Orientalism Art and race Art and society Gender identity in art Art -- Political aspects Photographers -- South Africa Painters -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2420 , http://hdl.handle.net/10962/d1002216
- Description: South African photographer Nontsikelelo “Lolo” Veleko and South African painter Tracy Payne explore different ways of communicating African realities. The visual imagery of these two artists focuses a lot on movement, challenging the rigidity of boundaries set by Western social constructs. In their work, Veleko and Payne critique the limitations of terms such as “authenticity.” It is extremely difficult to portray shifting notions of contemporary African identity in light of the stain of colonial philosophies which have, in times past, exoticised and appropriated the African body and ascribed conventions of “authenticity” to African representations. Undermining the burden of Western boundaries1, Veleko and Payne redefine what it means to operate in Africa today. Veleko seeks additional cultural realities to complicate her identity as a woman living in Africa while Payne uses concepts of movement to question the validity of structures which advocate an either/ or binary such as “East” and “West” and “masculinity” and “femininity”. By subtly merging aspects of these binaries in their representations, Veleko and Payne bring transnational possibilities to light by undermining the restrictions inscribed in the social and political history of (South) Africa with regard to collective and individual identities. Constructs of gender have contributed to a heightened sense of “African” “masculinity,” forming a stereotype of the African body which is difficult to break free from. Considering the notion of transnationalism and the issue of moving beyond boundaries, borrowing aspects of different cultures in attempt to better define a sense of self, Veleko and Payne engage in the sampling of different lifestyles and perspectives to better define their individualities. This thesis seeks to provide an analysis of the visual language used by Veleko and Payne to promote fluid “African” identities.
- Full Text:
- Date Issued: 2010
- Authors: Pycroft, Hayley
- Date: 2010
- Subjects: Veleko, Nontsikelelo -- Criticism and interpretation Payne, Tracy, 1965- -- Criticism and interpretation Afrocentrism Orientalism Art and race Art and society Gender identity in art Art -- Political aspects Photographers -- South Africa Painters -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2420 , http://hdl.handle.net/10962/d1002216
- Description: South African photographer Nontsikelelo “Lolo” Veleko and South African painter Tracy Payne explore different ways of communicating African realities. The visual imagery of these two artists focuses a lot on movement, challenging the rigidity of boundaries set by Western social constructs. In their work, Veleko and Payne critique the limitations of terms such as “authenticity.” It is extremely difficult to portray shifting notions of contemporary African identity in light of the stain of colonial philosophies which have, in times past, exoticised and appropriated the African body and ascribed conventions of “authenticity” to African representations. Undermining the burden of Western boundaries1, Veleko and Payne redefine what it means to operate in Africa today. Veleko seeks additional cultural realities to complicate her identity as a woman living in Africa while Payne uses concepts of movement to question the validity of structures which advocate an either/ or binary such as “East” and “West” and “masculinity” and “femininity”. By subtly merging aspects of these binaries in their representations, Veleko and Payne bring transnational possibilities to light by undermining the restrictions inscribed in the social and political history of (South) Africa with regard to collective and individual identities. Constructs of gender have contributed to a heightened sense of “African” “masculinity,” forming a stereotype of the African body which is difficult to break free from. Considering the notion of transnationalism and the issue of moving beyond boundaries, borrowing aspects of different cultures in attempt to better define a sense of self, Veleko and Payne engage in the sampling of different lifestyles and perspectives to better define their individualities. This thesis seeks to provide an analysis of the visual language used by Veleko and Payne to promote fluid “African” identities.
- Full Text:
- Date Issued: 2010
Beyond coming out: lesbians' stories of sexual identity in the context of a historically white university
- Authors: Gibson, Alexandra Farren
- Date: 2010
- Subjects: Lesbianism -- South Africa -- Grahamstown Homosexuality -- South Africa -- Grahamstown Coming out (Sexual orientation) -- South Africa -- Grahamstown College students -- South Africa -- Grahamstown -- Sexual behavior Rhodes University College students -- South Africa -- Grahamstown -- Attitudes College students -- South Africa -- Grahamstown -- Social conditions College students -- South Africa -- Grahamstown -- Conduct of life College students -- South Africa -- Grahamstown -- Social life and customs Homosexuality and education -- South Africa -- Grahamstown Gender identity in education -- South Africa -- Grahamstown Discourse analysis, Narrative -- Psychological aspects Discursive psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2981 , http://hdl.handle.net/10962/d1002490
- Description: Substantial contributions have been made by lesbian and gay developmental theorists in understanding the development of lesbian and gay sexual identities, or what has come to be known as the coming out process. “Coming out of the closet” has become a central metaphor, in western contexts, for the recognisable process gay men and lesbians undergo in order to claim a relatively stable and enduring sexual identity, while overcoming obstacles such as heterosexism. Lesbians’ sexual identities are examined in this thesis through a Foucauldian lens which is fused with a narrative-discursive perspective. The aim of this study is not to trace a progressive development of identity, but rather to consider how lesbians in this study are located within a specific context, namely, a historically white university in post-apartheid South Africa, and how their identities are dynamic products of ever-shifting socio-historical spaces. Eight lesbians’ stories are analysed using the narrative-discursive method, which allows for a consideration for how the construction and negotiation of identities is shaped and constrained by social and discursive conditions. The women in this study do utilise the concept of coming out to some extent in their stories, but this narrative does not entirely account for their experiences. Instead, these women’s accounts reflect the way in which they personally experience heterosexism, and how they constantly negotiate their sexual identities within certain social and geographical spaces. When the nuances of lesbians’ contexts are taken into account, it becomes clear that claiming a lesbian identity is more than just about “coming out”, and rather about an on-going process of identity management.
- Full Text:
- Date Issued: 2010
- Authors: Gibson, Alexandra Farren
- Date: 2010
- Subjects: Lesbianism -- South Africa -- Grahamstown Homosexuality -- South Africa -- Grahamstown Coming out (Sexual orientation) -- South Africa -- Grahamstown College students -- South Africa -- Grahamstown -- Sexual behavior Rhodes University College students -- South Africa -- Grahamstown -- Attitudes College students -- South Africa -- Grahamstown -- Social conditions College students -- South Africa -- Grahamstown -- Conduct of life College students -- South Africa -- Grahamstown -- Social life and customs Homosexuality and education -- South Africa -- Grahamstown Gender identity in education -- South Africa -- Grahamstown Discourse analysis, Narrative -- Psychological aspects Discursive psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2981 , http://hdl.handle.net/10962/d1002490
- Description: Substantial contributions have been made by lesbian and gay developmental theorists in understanding the development of lesbian and gay sexual identities, or what has come to be known as the coming out process. “Coming out of the closet” has become a central metaphor, in western contexts, for the recognisable process gay men and lesbians undergo in order to claim a relatively stable and enduring sexual identity, while overcoming obstacles such as heterosexism. Lesbians’ sexual identities are examined in this thesis through a Foucauldian lens which is fused with a narrative-discursive perspective. The aim of this study is not to trace a progressive development of identity, but rather to consider how lesbians in this study are located within a specific context, namely, a historically white university in post-apartheid South Africa, and how their identities are dynamic products of ever-shifting socio-historical spaces. Eight lesbians’ stories are analysed using the narrative-discursive method, which allows for a consideration for how the construction and negotiation of identities is shaped and constrained by social and discursive conditions. The women in this study do utilise the concept of coming out to some extent in their stories, but this narrative does not entirely account for their experiences. Instead, these women’s accounts reflect the way in which they personally experience heterosexism, and how they constantly negotiate their sexual identities within certain social and geographical spaces. When the nuances of lesbians’ contexts are taken into account, it becomes clear that claiming a lesbian identity is more than just about “coming out”, and rather about an on-going process of identity management.
- Full Text:
- Date Issued: 2010
Beyond teaching language: towards terminological primacy in learners' geometric conceptualisation
- Atebe, Humphrey U, Schäfer, Marc
- Authors: Atebe, Humphrey U , Schäfer, Marc
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140960 , vital:37932 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC20922
- Description: This paper reports on a specific aspect of a broader geometry conceptualisation study that sought to explore and explicate learners' knowledge of basic geometric terminology in selected Nigerian and South African high schools. It is framed by the notion that students' acquisition of the correct terminology in school geometry is important for their success in the subject. The original study further aimed to determine the relationship that might exist between a learner's ability in verbal geometry terminology tasks and his/her ability in visual geometry terminology tasks. A total of 144 learners (72 each from South Africa and Nigeria) were selected for the study, using both the stratified and the fish-bowl sampling techniques. A questionnaire consisting of a sixty-item multiple-choice objective test provided the data for the study. An overall percentage mean score of 44,17% obtained in the test indicated that learners in this study had only a limited knowledge of basic geometric terminology. The Nigerian subsample in the study had a weaker understanding of basic geometric terminology than their South African counterparts. Importantly, there were high positive correlations between participants' ability in verbal geometry terminology tasks and their ability in visual geometry terminology tasks. These results are consistent with those of several earlier studies, and provide a reasonably firm basis for certain recommendations to be made.
- Full Text:
- Date Issued: 2010
- Authors: Atebe, Humphrey U , Schäfer, Marc
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140960 , vital:37932 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC20922
- Description: This paper reports on a specific aspect of a broader geometry conceptualisation study that sought to explore and explicate learners' knowledge of basic geometric terminology in selected Nigerian and South African high schools. It is framed by the notion that students' acquisition of the correct terminology in school geometry is important for their success in the subject. The original study further aimed to determine the relationship that might exist between a learner's ability in verbal geometry terminology tasks and his/her ability in visual geometry terminology tasks. A total of 144 learners (72 each from South Africa and Nigeria) were selected for the study, using both the stratified and the fish-bowl sampling techniques. A questionnaire consisting of a sixty-item multiple-choice objective test provided the data for the study. An overall percentage mean score of 44,17% obtained in the test indicated that learners in this study had only a limited knowledge of basic geometric terminology. The Nigerian subsample in the study had a weaker understanding of basic geometric terminology than their South African counterparts. Importantly, there were high positive correlations between participants' ability in verbal geometry terminology tasks and their ability in visual geometry terminology tasks. These results are consistent with those of several earlier studies, and provide a reasonably firm basis for certain recommendations to be made.
- Full Text:
- Date Issued: 2010
Bioaccumulation and ecotoxicology of b-methylamino-l-alanine (BMAA) in model crop plants
- Niyonzima, Francois Niyongabo
- Authors: Niyonzima, Francois Niyongabo
- Date: 2010
- Subjects: Cyanobacteria , Environmental toxicology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10312 , http://hdl.handle.net/10948/1475 , Cyanobacteria , Environmental toxicology
- Description: Cyanobacteria are known to produce a variety of toxic compounds. β-N-methylamino-L-alanine (BMAA) is one of the neurotoxins produced by most cyanobacteria. BMAA has been implicated in amyotrophic lateral sclerosis / Parkinsonism dementia complex (ALS / PDC) and was suggested to contribute to this pathology after biomagnification and slow release of BMAA from a protein associated form. The uptake and accumulation of BMAA by the aquatic macrophyte Ceratophyllum demersum has recently been shown, but the consumption of aquatic macrophytes by humans is not typical. The uptake by, and accumulation in, crop plants (Nasturtium officinale and Daucus carota) was therefore investigated so as to establish the existence of any risk to humans from the consumption of plants irrigated with water from dams with high cyanobacterial biomass and therefore high BMAA levels. After the exposure to the BMAA through the growth medium, BMAA had no effect on growth and development of N. officinale and D. carota. The uptake and bioaccumulation of BMAA was observed in N. officinale and D. carota, and was found to be concentration-dependent. Both free and bound cellular BMAA was detected following BMAA exposure through the growth medium. The photosynthetic apparatus of N. officinale was not significantly damaged. The uptake and accumulation of BMAA in edible terrestrial plants may constitute another route of human exposure to BMAA; it may now be prudent to avoid spray irrigation of edible plants with waters from dams with high cyanobacterial biomass and therefore high BMAA levels. After uptake by plants, the cyanotoxins may induce oxidative stress. A recent study showed that BMAA has a significant inhibitory effect on the oxidative stress enzymes in C. demersum. Therefore, the toxicological effects on selected plants were investigated by a range of biochemical enzyme assays in order to establish the plant stress response to exogenous BMAA. The inhibition of antioxidant enzymes upon exposure of N. officinale to BMAA through the growth medium was observed. The inhibition of antioxidant defence enzymes by BMAA correlated with the BMAA bioaccumulation in N. officinale. Further investigations are needed to analyze the uptake, accumulation, and ecotoxicology of BMAA in other crop plants, and to examine the fate of BMAA in these plants particularly its distribution and metabolism.
- Full Text:
- Date Issued: 2010
- Authors: Niyonzima, Francois Niyongabo
- Date: 2010
- Subjects: Cyanobacteria , Environmental toxicology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10312 , http://hdl.handle.net/10948/1475 , Cyanobacteria , Environmental toxicology
- Description: Cyanobacteria are known to produce a variety of toxic compounds. β-N-methylamino-L-alanine (BMAA) is one of the neurotoxins produced by most cyanobacteria. BMAA has been implicated in amyotrophic lateral sclerosis / Parkinsonism dementia complex (ALS / PDC) and was suggested to contribute to this pathology after biomagnification and slow release of BMAA from a protein associated form. The uptake and accumulation of BMAA by the aquatic macrophyte Ceratophyllum demersum has recently been shown, but the consumption of aquatic macrophytes by humans is not typical. The uptake by, and accumulation in, crop plants (Nasturtium officinale and Daucus carota) was therefore investigated so as to establish the existence of any risk to humans from the consumption of plants irrigated with water from dams with high cyanobacterial biomass and therefore high BMAA levels. After the exposure to the BMAA through the growth medium, BMAA had no effect on growth and development of N. officinale and D. carota. The uptake and bioaccumulation of BMAA was observed in N. officinale and D. carota, and was found to be concentration-dependent. Both free and bound cellular BMAA was detected following BMAA exposure through the growth medium. The photosynthetic apparatus of N. officinale was not significantly damaged. The uptake and accumulation of BMAA in edible terrestrial plants may constitute another route of human exposure to BMAA; it may now be prudent to avoid spray irrigation of edible plants with waters from dams with high cyanobacterial biomass and therefore high BMAA levels. After uptake by plants, the cyanotoxins may induce oxidative stress. A recent study showed that BMAA has a significant inhibitory effect on the oxidative stress enzymes in C. demersum. Therefore, the toxicological effects on selected plants were investigated by a range of biochemical enzyme assays in order to establish the plant stress response to exogenous BMAA. The inhibition of antioxidant enzymes upon exposure of N. officinale to BMAA through the growth medium was observed. The inhibition of antioxidant defence enzymes by BMAA correlated with the BMAA bioaccumulation in N. officinale. Further investigations are needed to analyze the uptake, accumulation, and ecotoxicology of BMAA in other crop plants, and to examine the fate of BMAA in these plants particularly its distribution and metabolism.
- Full Text:
- Date Issued: 2010