Economic change in town and countryside in the former Transkei : land use, livelihoods and market linkages in Ngcobo, Eastern Cape, South Africa
- Authors: Nikelo, Nqaba Benedictor
- Date: 2018
- Subjects: Homelands (South Africa) Homelands (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/10768 , vital:35757
- Description: In 1913 in South Africa the natives of land act during apartheid resulted to the separation of South Africa. South Africa was divided into two areas where they were black and white areas. This act had a rule that said the black people can only move out of their lands only if employed as labourers by the whites. The white population was one-fifth of the population and was given 92.5 percent of the land while the rest of the population were blacks and they were restricted to stay on the 7.5 percent of land. In the Eastern Cape, two homelands were created: the Transkei (in 1951) and the Ciskei (in 1961). In 1963 the Transkei became the first homeland to be granted the status of 'self-governing territory within the Republic of South Africa’, with the Ciskei following suit in 1972. The apartheid policies caused economic failure and corruption because very little economic and infrastructural development took place in the homelands. According to the ‘legacy perspective’: the former homelands are historically-determined structural poverty traps. The objective of the study is to describe the extent and change of economic function/role of Ngcobo town and linkages with its surrounding villages. Availability or convenient sampling and random sampling techniques were used to collect primary data from farmers and surrounding villages. Descriptive statistics was used to profile farmers as well as the participants in the surrounding villages. Descriptive statistics was used to describe the change in the economy of Ngcobo town and the change in the economy of the surrounding rural areas. Households in the former homelands devote a large share of their total expenditure to food and beverages, and yet it would appear that a relatively small share of this food originates from these same rural areas. The point of departure of this report is the observation that rural areas are diverse, whereby some areas within the former homeland areas in particular exhibit signs of dynamism which are not understandable in terms of the ‘legacy perspective’.
- Full Text:
- Date Issued: 2018
- Authors: Nikelo, Nqaba Benedictor
- Date: 2018
- Subjects: Homelands (South Africa) Homelands (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/10768 , vital:35757
- Description: In 1913 in South Africa the natives of land act during apartheid resulted to the separation of South Africa. South Africa was divided into two areas where they were black and white areas. This act had a rule that said the black people can only move out of their lands only if employed as labourers by the whites. The white population was one-fifth of the population and was given 92.5 percent of the land while the rest of the population were blacks and they were restricted to stay on the 7.5 percent of land. In the Eastern Cape, two homelands were created: the Transkei (in 1951) and the Ciskei (in 1961). In 1963 the Transkei became the first homeland to be granted the status of 'self-governing territory within the Republic of South Africa’, with the Ciskei following suit in 1972. The apartheid policies caused economic failure and corruption because very little economic and infrastructural development took place in the homelands. According to the ‘legacy perspective’: the former homelands are historically-determined structural poverty traps. The objective of the study is to describe the extent and change of economic function/role of Ngcobo town and linkages with its surrounding villages. Availability or convenient sampling and random sampling techniques were used to collect primary data from farmers and surrounding villages. Descriptive statistics was used to profile farmers as well as the participants in the surrounding villages. Descriptive statistics was used to describe the change in the economy of Ngcobo town and the change in the economy of the surrounding rural areas. Households in the former homelands devote a large share of their total expenditure to food and beverages, and yet it would appear that a relatively small share of this food originates from these same rural areas. The point of departure of this report is the observation that rural areas are diverse, whereby some areas within the former homeland areas in particular exhibit signs of dynamism which are not understandable in terms of the ‘legacy perspective’.
- Full Text:
- Date Issued: 2018
Effects of production systems and canola meal supplementation on carcass and meat quality characteristics of spent laying hens
- Authors: Semwogerere, Farouk
- Date: 2018
- Subjects: Broilers (Chickens) -- Feeding and feeds Chickens -- Feeding and feeds Chicken industry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9242 , vital:34309
- Description: This study evaluated the carcass and meat quality traits of spent laying hens as influenced by production systems (conventional cages and free range) and the inclusion/exclusion of canola meal in their diets. A total of 30 free range and 60 battery cage reared Lohmann Brown-Elite spent laying hens were obtained from a commercial egg producer. The 30 free range hens (53 weeks of age) and 30 of the caged hens (40 weeks of age) were fed a conventional diet, while the remaining 30 caged hens (48 weeks of age) were fed a diet supplemented with canola meal (20 percent). Carcass, portion and organ weights were determined. Physical attributes and proximate composition were analyzed for, with additional fatty acids and sensory profiles being determined for the effects of canola meal inclusion in the diet. Caged hens had heavier (P ≤ 0.05) warm and cold carcasses, thigh, wing and feet compared to free range hens. The percentages of the breast (26.1 ± 0.51 vs. 28.3 ± 0.28), drum, breast bones, breast thaw and cooking losses and thigh cooking loss were lower (P ≤ 0.05) for caged hens than for free range hens. Free range hens had heavier (P ≤ 0.05) gizzards (33.9 ± 1.04 vs. 30.5 ± 0.73) and bones and a lower (P ≤ 0.05) breast meat percentage (47.3 ± 0.94 vs. 51.7 ± 1.35). Meat redness (a*) (0.54 ± 0.222 vs. 1.40 ± 0.135) and hue angle value, skin redness (a*), breast and thigh, Warner-Bratzler shear force (WBSF) values (breast: 12.37 ± 0.411 vs. 17.10 ± 0.751, thigh: 29.68 ± 0.306 vs. 39.75 ± 0.826), breast moisture and thigh ash content were lower (P ≤ 0.05) for caged hens than free range hens. Caged hens had higher (P ≤ 0.05) thigh thaw loss and breast ash content than free range hens. Canola-fed hens had higher (P ≤ 0.05) drum percentages, breast bone weights and percentages, with lower (P ≤ 0.05) thigh and breast meat percentages. Canola-fed hens had lower (P ≤ 0.05) thaw losses, skin yellowness (b*) and Chroma values, breast fat content with higher cooking losses, skin redness (a*) and hue angle value, as well as breast WBSF (12.37 ± 0.411 vs. 15.43 ± 0.600). Palmitic acid, stearic acid, heneicosanoic acid acid, palmitoleic acid, saturated fatty acids (SFA) (34.0 ± 0.56 vs. 38.7 ± 0.71), n-6:n-3 polyunsaturated fatty acids (PUFA) ratio (5.5 ± 0.13 vs. 7.2 ± 0.28), atherogenic index (IA), thrombogenic index (IT), delta-5 desaturase (D5D, elongase index and thiosterase index were lower (P ≤ 0.05) for canola-fed hen breast meat. Breast meat from conventionally fed hens had lower (P ≤ 0.05) myristic acid, lignoceric acid, nervonic acid, alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), PUFA:SFA ratio (0.7 ± 0.05 vs. 0.9 ± 0.02), n-3 PUFA (3.4 ± 0.31 vs. 5.1 ± 0.17), hypocholesterolemic:Hypercholesterolaemic (h/H), stearoyl-CoA desaturase 16 (SCD16) and stearoyl-CoA desaturase 18 (SCD18). The breast meat from conventionally fed hens had lower (P ≤ 0.05) metallic flavor than that from canola-fed hens. Strong positive correlations were observed for overall aroma with chicken (r = 0.965, P < 0.001) and brothy aroma (r = 0.827, P < 0.001); overall aroma with overall flavor (r = 0.680, P < 0.001), chicken flavor (r = 0.668, P < 0.001) and brothy flavor (r = 0.548, P = 0.006); initial juiciness with sustained juiciness (r = 0.771, P < 0.001) and tenderness (r = 0.537, P = 0.007); sustained juiciness with tenderness (r = 0.790, P < 0.001) and chewiness with residue (r = 0.783, P < 0.001). Whilst strong negative correlations were observed for: sustained juiciness with chewiness (r = -0.655, P = 0.001) and residue (r = 0.783, P < 0.001) and for tenderness with chewiness (r = 0.845, P < 0.001) and residue (r = -0.855, P < 0.001). Results of this study highlight that a free range production system when compared to a conventional cage system increased undesirable carcass and physical meat traits of spent laying hens. On the other hand, canola meal inclusion incorporates beneficial health aspects without affecting the sensory profile of meat derived from spent laying hens, both groups of hens being reared in battery cage system. Spent laying hen breasts can be consumed as a functional food (especially canolafed) since the fat content and composition was observed to be close to that which is recommended for a healthy diet.
- Full Text:
- Date Issued: 2018
- Authors: Semwogerere, Farouk
- Date: 2018
- Subjects: Broilers (Chickens) -- Feeding and feeds Chickens -- Feeding and feeds Chicken industry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9242 , vital:34309
- Description: This study evaluated the carcass and meat quality traits of spent laying hens as influenced by production systems (conventional cages and free range) and the inclusion/exclusion of canola meal in their diets. A total of 30 free range and 60 battery cage reared Lohmann Brown-Elite spent laying hens were obtained from a commercial egg producer. The 30 free range hens (53 weeks of age) and 30 of the caged hens (40 weeks of age) were fed a conventional diet, while the remaining 30 caged hens (48 weeks of age) were fed a diet supplemented with canola meal (20 percent). Carcass, portion and organ weights were determined. Physical attributes and proximate composition were analyzed for, with additional fatty acids and sensory profiles being determined for the effects of canola meal inclusion in the diet. Caged hens had heavier (P ≤ 0.05) warm and cold carcasses, thigh, wing and feet compared to free range hens. The percentages of the breast (26.1 ± 0.51 vs. 28.3 ± 0.28), drum, breast bones, breast thaw and cooking losses and thigh cooking loss were lower (P ≤ 0.05) for caged hens than for free range hens. Free range hens had heavier (P ≤ 0.05) gizzards (33.9 ± 1.04 vs. 30.5 ± 0.73) and bones and a lower (P ≤ 0.05) breast meat percentage (47.3 ± 0.94 vs. 51.7 ± 1.35). Meat redness (a*) (0.54 ± 0.222 vs. 1.40 ± 0.135) and hue angle value, skin redness (a*), breast and thigh, Warner-Bratzler shear force (WBSF) values (breast: 12.37 ± 0.411 vs. 17.10 ± 0.751, thigh: 29.68 ± 0.306 vs. 39.75 ± 0.826), breast moisture and thigh ash content were lower (P ≤ 0.05) for caged hens than free range hens. Caged hens had higher (P ≤ 0.05) thigh thaw loss and breast ash content than free range hens. Canola-fed hens had higher (P ≤ 0.05) drum percentages, breast bone weights and percentages, with lower (P ≤ 0.05) thigh and breast meat percentages. Canola-fed hens had lower (P ≤ 0.05) thaw losses, skin yellowness (b*) and Chroma values, breast fat content with higher cooking losses, skin redness (a*) and hue angle value, as well as breast WBSF (12.37 ± 0.411 vs. 15.43 ± 0.600). Palmitic acid, stearic acid, heneicosanoic acid acid, palmitoleic acid, saturated fatty acids (SFA) (34.0 ± 0.56 vs. 38.7 ± 0.71), n-6:n-3 polyunsaturated fatty acids (PUFA) ratio (5.5 ± 0.13 vs. 7.2 ± 0.28), atherogenic index (IA), thrombogenic index (IT), delta-5 desaturase (D5D, elongase index and thiosterase index were lower (P ≤ 0.05) for canola-fed hen breast meat. Breast meat from conventionally fed hens had lower (P ≤ 0.05) myristic acid, lignoceric acid, nervonic acid, alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), PUFA:SFA ratio (0.7 ± 0.05 vs. 0.9 ± 0.02), n-3 PUFA (3.4 ± 0.31 vs. 5.1 ± 0.17), hypocholesterolemic:Hypercholesterolaemic (h/H), stearoyl-CoA desaturase 16 (SCD16) and stearoyl-CoA desaturase 18 (SCD18). The breast meat from conventionally fed hens had lower (P ≤ 0.05) metallic flavor than that from canola-fed hens. Strong positive correlations were observed for overall aroma with chicken (r = 0.965, P < 0.001) and brothy aroma (r = 0.827, P < 0.001); overall aroma with overall flavor (r = 0.680, P < 0.001), chicken flavor (r = 0.668, P < 0.001) and brothy flavor (r = 0.548, P = 0.006); initial juiciness with sustained juiciness (r = 0.771, P < 0.001) and tenderness (r = 0.537, P = 0.007); sustained juiciness with tenderness (r = 0.790, P < 0.001) and chewiness with residue (r = 0.783, P < 0.001). Whilst strong negative correlations were observed for: sustained juiciness with chewiness (r = -0.655, P = 0.001) and residue (r = 0.783, P < 0.001) and for tenderness with chewiness (r = 0.845, P < 0.001) and residue (r = -0.855, P < 0.001). Results of this study highlight that a free range production system when compared to a conventional cage system increased undesirable carcass and physical meat traits of spent laying hens. On the other hand, canola meal inclusion incorporates beneficial health aspects without affecting the sensory profile of meat derived from spent laying hens, both groups of hens being reared in battery cage system. Spent laying hen breasts can be consumed as a functional food (especially canolafed) since the fat content and composition was observed to be close to that which is recommended for a healthy diet.
- Full Text:
- Date Issued: 2018
Evaluation and identification of microbial contaminants in polyherbal medicines used for the treatment of tuberculosis in Amathole District Municipality, Eastern Cape Province, South Africa
- Authors: Famewo, Elizabeth Bosede
- Date: 2018
- Subjects: Tuberculosis -- Treatment -- South Africa Mycobacterial diseases -- South Africa -- Eastern Cape Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9680 , vital:34818
- Description: Tuberculosis is caused by Mycobacterium tuberculosis. The emergence of drug-resistant strains of this organism has become a global public health problem. In the continuing search for effective treatment, polyherbal medicines offer a great hope in the development of alternative drugs for the treatment of tuberculosis. The use of herbal formulations for therapeutic purposes has significantly increased in the developed and developing countries because of their curative property, less toxicity and minimal side effects. However, there is little information on their safety and effectiveness in the literature. To address this, polyherbal medicines used for the treatment of tuberculosis in the Eastern Cape Province of South Africa were evaluated. Ethno-medicinal survey was conducted through semi-structured questionnaires coupled with informal conversations with the herbal sellers in five communities in the study area. Bacterial and fungal DNA was extracted from the polyherbal medicines purchased. A fragment of the bacterial 16S rRNA gene and internal transcribed spacer region of the fungal rRNA operon were amplified with universal primers 27F and 518R, and ITS1 and ITS4 respectively. Following standard procedures, the amplicons were finally run on Illumina’s MiSeq platform. Furthermore, the remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. Agar dilution method was used to determine the minimum inhibitory concentration (MIC) of the remedies against eight bacteria and three fungi isolates. The herbal preparations were assayed for their toxicity using hatchability success and larval mortality of Artemia salina Leach. Finally, their nutritive properties were analysed using an inductively coupled plasma optical emission spectrometer for mineral analysis while the vitamins were determined using standardized methods A total of nine polyherbal preparations were collected. The herbs used for the preparation of these remedies belong to 20 families. Apiaceae [5(25 percent)] was the most prominent plant family used, followed by Liliaceae [4(20 percent)], Strychnaceae [4(20 percent)], Rutaceae [4(20 percent)] and Hypoxidaceae [3(15 percent)]. The two most frequently used plants were Allium sativum L. (Liliaceae) and Strychnos decussata (Pappe) Gilg. (Strychnaceae). Rhizomes was the most common parts used, followed by the roots and barks. The herbal medicines were prepared mainly by infusion and decoction. The presences of pathogenic and non-pathogenic bacteria were identified in the polyherbal medicines. Generally, the most common bacteria identified from the samples were Bacillus sp., Enterobacter sp., Klebsiella sp., Rahnella sp., Paenibacillus sp., Clostridium sp. and Pantoea sp. The predominant mycoflora obtained belongs to different genera or species of fungi; these include Alternaria, Candida, Ramularia, Cladosporium, Penicillium, Aspergillus and Malassezia. The susceptibility testing revealed that all the remedies contain anti-tubercular activity against M. tuberculosis H37Rv at concentrations below 50 ug/ml. Seven of the polyherbal preparations showed activity at concentrations below 25 ug/ml. The MIC values exhibited inhibitory activity at 1.562 μg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 μg/ml when compared to the polyherbal remedies. The inhibitory activity of the polyherbal medicines based on the overall MIC revealed that Hogsback first site (HBfs) and Fort Beaufort (FB) remedies were the most active remedies against the bacterial isolates at the concentration of 2.5 mg/mL. Among the nine herbal formulations, only King Williams Town site A (KWTa) remedy showed activity against Aspergillus niger and Aspergillus fumigatus with the MIC valve of 2.5 mg/mL. While King Williams Town site C (KWTc) and Hogsback third site (HBts) had the highest activity at 1.25 mg/mL against Candida albicans, the remaining remedies were active at 2.5 mg/mL. The percentage hatchability of 44.42 percent, 42.96 percent and 39.70 percent were observed in A. salina cysts incubated with herbal preparations from KWTa, HBfs and HBts respectively. The hatching success of the cysts in these remedies was significantly higher than the positive control (nystatin) and the negative control (sea water) at p < 0.05. The mortality of A. salina nauplii incubated in Alice (AL), King Williams Town site B (KWTb) and KWTc remedies were significantly higher than when larvae were incubated in both controls. Based on Meyer’s index, the LD50 of each polyherbal medicine was between 2.9 and 4.0 mg/ml, the LD50 values greater than 1 mg/ml, an indication that they are not toxic. The polyherbal preparations were found to be rich in vitamins and mineral nutrients. Calcium was the highest macronutrient detected while the lowest nutrient was phosphorus. Iron was the highest micronutrient in the majority of the polyherbal preparations while the lowest value was recorded for copper. Vitamin C was absent in the herbal preparations while vitamin A and E were detected. This study provides significant ethno-medicinal information on polyherbal medicines used for the treatment of TB in the study area. The presence of the identified bacteria and fungi in the herbal formulations is a cause for concern. However, the ability of the remedies to possess activity against Mycobacterium tuberculosis and other pathogenic microorganisms associated with tuberculosis infection makes them potential sources of new antimycobacterial agents. Also, they are rich sources of mineral nutrients, and are as well non-toxic, thus, they are safe for consumption. In view of their anti-tubercular properties, this study has provided a better understanding of the reasons why TB-patients make use of these polyherbal formulations. Also, the study supports the folkloric use of polyherbal medicines in the treatment of tuberculosis in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Famewo, Elizabeth Bosede
- Date: 2018
- Subjects: Tuberculosis -- Treatment -- South Africa Mycobacterial diseases -- South Africa -- Eastern Cape Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9680 , vital:34818
- Description: Tuberculosis is caused by Mycobacterium tuberculosis. The emergence of drug-resistant strains of this organism has become a global public health problem. In the continuing search for effective treatment, polyherbal medicines offer a great hope in the development of alternative drugs for the treatment of tuberculosis. The use of herbal formulations for therapeutic purposes has significantly increased in the developed and developing countries because of their curative property, less toxicity and minimal side effects. However, there is little information on their safety and effectiveness in the literature. To address this, polyherbal medicines used for the treatment of tuberculosis in the Eastern Cape Province of South Africa were evaluated. Ethno-medicinal survey was conducted through semi-structured questionnaires coupled with informal conversations with the herbal sellers in five communities in the study area. Bacterial and fungal DNA was extracted from the polyherbal medicines purchased. A fragment of the bacterial 16S rRNA gene and internal transcribed spacer region of the fungal rRNA operon were amplified with universal primers 27F and 518R, and ITS1 and ITS4 respectively. Following standard procedures, the amplicons were finally run on Illumina’s MiSeq platform. Furthermore, the remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. Agar dilution method was used to determine the minimum inhibitory concentration (MIC) of the remedies against eight bacteria and three fungi isolates. The herbal preparations were assayed for their toxicity using hatchability success and larval mortality of Artemia salina Leach. Finally, their nutritive properties were analysed using an inductively coupled plasma optical emission spectrometer for mineral analysis while the vitamins were determined using standardized methods A total of nine polyherbal preparations were collected. The herbs used for the preparation of these remedies belong to 20 families. Apiaceae [5(25 percent)] was the most prominent plant family used, followed by Liliaceae [4(20 percent)], Strychnaceae [4(20 percent)], Rutaceae [4(20 percent)] and Hypoxidaceae [3(15 percent)]. The two most frequently used plants were Allium sativum L. (Liliaceae) and Strychnos decussata (Pappe) Gilg. (Strychnaceae). Rhizomes was the most common parts used, followed by the roots and barks. The herbal medicines were prepared mainly by infusion and decoction. The presences of pathogenic and non-pathogenic bacteria were identified in the polyherbal medicines. Generally, the most common bacteria identified from the samples were Bacillus sp., Enterobacter sp., Klebsiella sp., Rahnella sp., Paenibacillus sp., Clostridium sp. and Pantoea sp. The predominant mycoflora obtained belongs to different genera or species of fungi; these include Alternaria, Candida, Ramularia, Cladosporium, Penicillium, Aspergillus and Malassezia. The susceptibility testing revealed that all the remedies contain anti-tubercular activity against M. tuberculosis H37Rv at concentrations below 50 ug/ml. Seven of the polyherbal preparations showed activity at concentrations below 25 ug/ml. The MIC values exhibited inhibitory activity at 1.562 μg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 μg/ml when compared to the polyherbal remedies. The inhibitory activity of the polyherbal medicines based on the overall MIC revealed that Hogsback first site (HBfs) and Fort Beaufort (FB) remedies were the most active remedies against the bacterial isolates at the concentration of 2.5 mg/mL. Among the nine herbal formulations, only King Williams Town site A (KWTa) remedy showed activity against Aspergillus niger and Aspergillus fumigatus with the MIC valve of 2.5 mg/mL. While King Williams Town site C (KWTc) and Hogsback third site (HBts) had the highest activity at 1.25 mg/mL against Candida albicans, the remaining remedies were active at 2.5 mg/mL. The percentage hatchability of 44.42 percent, 42.96 percent and 39.70 percent were observed in A. salina cysts incubated with herbal preparations from KWTa, HBfs and HBts respectively. The hatching success of the cysts in these remedies was significantly higher than the positive control (nystatin) and the negative control (sea water) at p < 0.05. The mortality of A. salina nauplii incubated in Alice (AL), King Williams Town site B (KWTb) and KWTc remedies were significantly higher than when larvae were incubated in both controls. Based on Meyer’s index, the LD50 of each polyherbal medicine was between 2.9 and 4.0 mg/ml, the LD50 values greater than 1 mg/ml, an indication that they are not toxic. The polyherbal preparations were found to be rich in vitamins and mineral nutrients. Calcium was the highest macronutrient detected while the lowest nutrient was phosphorus. Iron was the highest micronutrient in the majority of the polyherbal preparations while the lowest value was recorded for copper. Vitamin C was absent in the herbal preparations while vitamin A and E were detected. This study provides significant ethno-medicinal information on polyherbal medicines used for the treatment of TB in the study area. The presence of the identified bacteria and fungi in the herbal formulations is a cause for concern. However, the ability of the remedies to possess activity against Mycobacterium tuberculosis and other pathogenic microorganisms associated with tuberculosis infection makes them potential sources of new antimycobacterial agents. Also, they are rich sources of mineral nutrients, and are as well non-toxic, thus, they are safe for consumption. In view of their anti-tubercular properties, this study has provided a better understanding of the reasons why TB-patients make use of these polyherbal formulations. Also, the study supports the folkloric use of polyherbal medicines in the treatment of tuberculosis in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2018
Isolation and characterization of E. coli and Campylobacter spp. from diarrhoeal samples collected from selected hospitals in Amathole District Municipality, Eastern Cape, South Africa
- Authors: Omolajaiye, Sunday Abraham
- Date: 2018
- Subjects: Escherichia coli infections Campylobacter infections Diarrhea
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6213 , vital:29515
- Description: Approximately 2-4 billion cases of infectious diarrhoea occur every year, with the highest numbers recorded in sub-Saharan Africa. It remains the most common public health issue among children in developing nations. The purpose of this research was to unfold the prevalence of diarrhoeagenic E. coli and Campylobacter pathotypes as well as elucidate their antibiogram characteristics in diarrhoeal stool samples collected in some medical facilities in Eastern Cape Province, South Africa. Two hundred stool samples were collected from both inpatients and outpatients from male and females of all age groups attending selected medical facilities in the study area. Isolation and characterization of both organisms were done using culture based and molecular methods. Antibiotic susceptibility patterns of identified isolates were determined against a panel of 12 antimicrobial agents. One hundred and twenty presumptive E. coli isolates and 42 presumptive isolates of Campylobacter spp. Were isolated. Eighty-two percent (82 percent) of the presumptive E. coli isolates were confirmed as E. coli while 46.3 percent belonged to Campylobacter spp. Pathotyping of the diarrhoeagenic E. coli isolates by Polymerase chain reaction (PCR) showed the following prevalences: DAEC 43 (32 percent), EHEC 18 (17 percent), EIEC 11 (10 percent) and EPEC 18 (17 percent). EAEC and ETEC were not detected, while for Campylobacter spp. 37 (88 percent) were C. jejuni, and C. coli was not detected. A total of 12 (32.4 percent) of the confirmed Campylobacter jejuni isolates were found to possess the fliM gene, 9 (24.3 percent) possessed the flhA gene and only 6 (16.2 percent) harboured the gene flgE2. None were positive for the flaA, flab and flhB genes.The antibiotic resistance patterns observed among the E. coli isolates were high against ampicillin (98.1 percent), chloramphenicol (94.3 percent) and tetracycline (90.6 percent). For Campylobacter spp., resistance observed were: chloramphenicol (91.6 percent), tetracycline (25.2 percent), erythromycin (49.6 percent) and gentamycin (56.4 percent). A lesser resistance against imipenem (35.9 percent) and quinolone (ciprofloxacin) (45.5 percent) were exhibited by the E.coli isolates. 10.8 percent and 20.3 percent of the Campylobacter isolates were resistant to imipenem and ciprofloxacin respectively. The presence of chloramphenicol (CatA1) and tetracycline (tetA) resistance genes were detected in 94 percent and 89 percent of E. coli isolates respectively while 98 percent of Campylobacter spp. Harboured the catA1 resistance gene. It could be deduced from this study that E. coli and Campylobacter spp. are predomiant enteric pathogens as the etiologic agents of diarrhoea in the study community, and that their antimicrobial resistance is high in the study location. The need to develop strategies to prevent infection and control resistant organisms is evident.
- Full Text:
- Date Issued: 2018
- Authors: Omolajaiye, Sunday Abraham
- Date: 2018
- Subjects: Escherichia coli infections Campylobacter infections Diarrhea
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6213 , vital:29515
- Description: Approximately 2-4 billion cases of infectious diarrhoea occur every year, with the highest numbers recorded in sub-Saharan Africa. It remains the most common public health issue among children in developing nations. The purpose of this research was to unfold the prevalence of diarrhoeagenic E. coli and Campylobacter pathotypes as well as elucidate their antibiogram characteristics in diarrhoeal stool samples collected in some medical facilities in Eastern Cape Province, South Africa. Two hundred stool samples were collected from both inpatients and outpatients from male and females of all age groups attending selected medical facilities in the study area. Isolation and characterization of both organisms were done using culture based and molecular methods. Antibiotic susceptibility patterns of identified isolates were determined against a panel of 12 antimicrobial agents. One hundred and twenty presumptive E. coli isolates and 42 presumptive isolates of Campylobacter spp. Were isolated. Eighty-two percent (82 percent) of the presumptive E. coli isolates were confirmed as E. coli while 46.3 percent belonged to Campylobacter spp. Pathotyping of the diarrhoeagenic E. coli isolates by Polymerase chain reaction (PCR) showed the following prevalences: DAEC 43 (32 percent), EHEC 18 (17 percent), EIEC 11 (10 percent) and EPEC 18 (17 percent). EAEC and ETEC were not detected, while for Campylobacter spp. 37 (88 percent) were C. jejuni, and C. coli was not detected. A total of 12 (32.4 percent) of the confirmed Campylobacter jejuni isolates were found to possess the fliM gene, 9 (24.3 percent) possessed the flhA gene and only 6 (16.2 percent) harboured the gene flgE2. None were positive for the flaA, flab and flhB genes.The antibiotic resistance patterns observed among the E. coli isolates were high against ampicillin (98.1 percent), chloramphenicol (94.3 percent) and tetracycline (90.6 percent). For Campylobacter spp., resistance observed were: chloramphenicol (91.6 percent), tetracycline (25.2 percent), erythromycin (49.6 percent) and gentamycin (56.4 percent). A lesser resistance against imipenem (35.9 percent) and quinolone (ciprofloxacin) (45.5 percent) were exhibited by the E.coli isolates. 10.8 percent and 20.3 percent of the Campylobacter isolates were resistant to imipenem and ciprofloxacin respectively. The presence of chloramphenicol (CatA1) and tetracycline (tetA) resistance genes were detected in 94 percent and 89 percent of E. coli isolates respectively while 98 percent of Campylobacter spp. Harboured the catA1 resistance gene. It could be deduced from this study that E. coli and Campylobacter spp. are predomiant enteric pathogens as the etiologic agents of diarrhoea in the study community, and that their antimicrobial resistance is high in the study location. The need to develop strategies to prevent infection and control resistant organisms is evident.
- Full Text:
- Date Issued: 2018
Extraction and characterization of antimicrobial compounds from selected marine invertebrates collected from Phillip's Reef, Port Elizabeth in the Eastern Cape province of South Africa
- Authors: Kibungu, Cuthbert Wasswa
- Date: 2018
- Subjects: Invertebrates Bioactive compounds Anti-infective agents
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/11751 , vital:39103
- Description: Introduction: The marine environment is rich in the biodiversity of medically significant invertebrate species such as sponges, ascidians, molluscs and bryozoans. Such a diverse environment is a potential source of a great variety of secondary metabolite production. Research in marine natural product discovery is gaining ground with the development of new therapeutic drugs of antimicrobial potential. Aim: This study seeks to evaluate, and identify bioactive compounds obtained from marine invertebrates collected from Phillip’s Reef in Algoa Bay. Methodology: Marine invertebrates were collected from the Phillip’s Reef in Algoa Bay, Port Elizabeth, at a depth of 12 m and the physichochemical parameters at the site of sample collection were recorded onsite. Sampling was done once over the four seasons in South Africa. Sections of each specimen were sent for identification, and extraction of compounds was done using organic solvents [methanol (95percent), hexane (95percent), petroleum ether (95percent), chloroform (95percent) and ethyl acetate (95percent)]. A ratio of 95percent the respective solvents was achieved by the following (1:19), organic solvent combinations [dichloromethane: methanol (1:1), hexane: chloroform: methanol (1:2:1)] and aqueous solution of water. Solvent optimization was done by measuring the absorbance of S. aureus (ATCC 49476) in Mueller Hinton Broth containing crude extracts at 600 nm. The appropriate solvent was then selected for further extraction of bioactive compounds from the specimens. Antimicrobial activity of the crude extracts was evaluated using the standard agar well diffusion method on test pathogens, namely, methicillin-resistant Staphylococcus aureus (ATCC 49476), clostridium difficile (ATCC 9689), Pseudomonas aeruginosa (ATCC 10145), Candida albicans (ATCC 10231) and Aspergillus fumigatus (ATCC 204305). Different concentrations of the crude extracts were used [100percent, 80percent, 60percent, 40percent and 30percent (v:v)] and the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined. Selected bioactive crude extracts were further evaluated for phytochemicals before being purified by subjecting them to Sephadex-G75 column chromatography, using 75percent ethyl acetate as the mobile phase. Bioactive crude extracts fractions obtained following column chromatography were subjected to Electron Spray Ionization Time of Flight (ESI-TOF) analysis using The Bruker Daltonics maXis compact ESI Quadrupole TOF instrument to detect and identify compounds present. Peak identification was done using the blast software contained in Open Chrom Community Edition (Alder), open source software for chromatography and mass spectrometry spectrum analysis. Results: Sixty-seven different marine invertebrate species were collected over the 4 seasons. A mean temperature of 17.35oC ± 2.06 was recorded over all four seasons with the Autumn exhibiting the highest temperature (20oC). Salinity readings obtained ranged between 35.12 psu and 35.27 psu. A stable mean pH range of 8.08–8.78 was also recorded across all four seasons. Salinity and pH readings conformed to the standards set by the South African Water Quality Guidelines. The Spring season exhibited the highest turbidity of 2.97 NTU compared to other seasons. Ethyl acetate and dichloromethane: methanol (1:1) extracts yielded the best inhibitory results. Approximately 60percent (4/67) of the marine invertebrate specimens showed bioactivity against some of the test pathogens. Both ethyl acetate and dichloromethane methanol crude extracts of S14 and S34 showed a broad spectrum of antimicrobial activity against both bacteria and fungi. The C6 ethyl acetate crude extracts were highly active against MRSA, as inhibition zones of 45 mm were observed. MIC at 30percent concentrations was observed for very few crude extracts against the five pathogens. Sixty-three ethyl acetate crude extracts contained phytochemicals while only 35 dichloromethane: methanol crude extracts contained phytochemicals. Neither ethyl acetate and dichloromethane: methanol crude extracts of S34 (Psammopsinia sp. 1) that were biologically active had any phytochemicals. Canadine, Ginkolide A, Apigenin, Amygdalin, 10-hydroxy-Camptothecin, Catechin, Beta-Peltatin and 6 Ethoxy-3(4'-hydroxyphenyl)-4-methylcoumarin were identified in the crude extracts. Conclusion: Marine invertebrate species located at Phillip’s Reef produce compounds with antimicrobial potential. These compounds are biologically active against human pathogenic microorganisms. The best solvent to use for the extraction of these biologically significant metabolites is ethyl acetate, as this study achieved outstanding results from ethyl acetate crude extracts in the form of high zones of inhibition, for example the sponge Ectyonopsis flabellate, which exhibited mean inhibition zones of 45 mm against Aspergillus fumigatus. Similar bioactivity was also observed with Tedania (Tedania) Stylonychaeta against Methicillin Resistant Staphylococcus aureus. This is the first study done on some of the marine sponges and ascidians in the Phillip’s Reef, and therefore further evaluation of the purified compounds is necessary in order to obtain the identity of the pure compounds and possibly determine the mechanism of action, and synthesize structural analogues for further studies.
- Full Text:
- Date Issued: 2018
- Authors: Kibungu, Cuthbert Wasswa
- Date: 2018
- Subjects: Invertebrates Bioactive compounds Anti-infective agents
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/11751 , vital:39103
- Description: Introduction: The marine environment is rich in the biodiversity of medically significant invertebrate species such as sponges, ascidians, molluscs and bryozoans. Such a diverse environment is a potential source of a great variety of secondary metabolite production. Research in marine natural product discovery is gaining ground with the development of new therapeutic drugs of antimicrobial potential. Aim: This study seeks to evaluate, and identify bioactive compounds obtained from marine invertebrates collected from Phillip’s Reef in Algoa Bay. Methodology: Marine invertebrates were collected from the Phillip’s Reef in Algoa Bay, Port Elizabeth, at a depth of 12 m and the physichochemical parameters at the site of sample collection were recorded onsite. Sampling was done once over the four seasons in South Africa. Sections of each specimen were sent for identification, and extraction of compounds was done using organic solvents [methanol (95percent), hexane (95percent), petroleum ether (95percent), chloroform (95percent) and ethyl acetate (95percent)]. A ratio of 95percent the respective solvents was achieved by the following (1:19), organic solvent combinations [dichloromethane: methanol (1:1), hexane: chloroform: methanol (1:2:1)] and aqueous solution of water. Solvent optimization was done by measuring the absorbance of S. aureus (ATCC 49476) in Mueller Hinton Broth containing crude extracts at 600 nm. The appropriate solvent was then selected for further extraction of bioactive compounds from the specimens. Antimicrobial activity of the crude extracts was evaluated using the standard agar well diffusion method on test pathogens, namely, methicillin-resistant Staphylococcus aureus (ATCC 49476), clostridium difficile (ATCC 9689), Pseudomonas aeruginosa (ATCC 10145), Candida albicans (ATCC 10231) and Aspergillus fumigatus (ATCC 204305). Different concentrations of the crude extracts were used [100percent, 80percent, 60percent, 40percent and 30percent (v:v)] and the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined. Selected bioactive crude extracts were further evaluated for phytochemicals before being purified by subjecting them to Sephadex-G75 column chromatography, using 75percent ethyl acetate as the mobile phase. Bioactive crude extracts fractions obtained following column chromatography were subjected to Electron Spray Ionization Time of Flight (ESI-TOF) analysis using The Bruker Daltonics maXis compact ESI Quadrupole TOF instrument to detect and identify compounds present. Peak identification was done using the blast software contained in Open Chrom Community Edition (Alder), open source software for chromatography and mass spectrometry spectrum analysis. Results: Sixty-seven different marine invertebrate species were collected over the 4 seasons. A mean temperature of 17.35oC ± 2.06 was recorded over all four seasons with the Autumn exhibiting the highest temperature (20oC). Salinity readings obtained ranged between 35.12 psu and 35.27 psu. A stable mean pH range of 8.08–8.78 was also recorded across all four seasons. Salinity and pH readings conformed to the standards set by the South African Water Quality Guidelines. The Spring season exhibited the highest turbidity of 2.97 NTU compared to other seasons. Ethyl acetate and dichloromethane: methanol (1:1) extracts yielded the best inhibitory results. Approximately 60percent (4/67) of the marine invertebrate specimens showed bioactivity against some of the test pathogens. Both ethyl acetate and dichloromethane methanol crude extracts of S14 and S34 showed a broad spectrum of antimicrobial activity against both bacteria and fungi. The C6 ethyl acetate crude extracts were highly active against MRSA, as inhibition zones of 45 mm were observed. MIC at 30percent concentrations was observed for very few crude extracts against the five pathogens. Sixty-three ethyl acetate crude extracts contained phytochemicals while only 35 dichloromethane: methanol crude extracts contained phytochemicals. Neither ethyl acetate and dichloromethane: methanol crude extracts of S34 (Psammopsinia sp. 1) that were biologically active had any phytochemicals. Canadine, Ginkolide A, Apigenin, Amygdalin, 10-hydroxy-Camptothecin, Catechin, Beta-Peltatin and 6 Ethoxy-3(4'-hydroxyphenyl)-4-methylcoumarin were identified in the crude extracts. Conclusion: Marine invertebrate species located at Phillip’s Reef produce compounds with antimicrobial potential. These compounds are biologically active against human pathogenic microorganisms. The best solvent to use for the extraction of these biologically significant metabolites is ethyl acetate, as this study achieved outstanding results from ethyl acetate crude extracts in the form of high zones of inhibition, for example the sponge Ectyonopsis flabellate, which exhibited mean inhibition zones of 45 mm against Aspergillus fumigatus. Similar bioactivity was also observed with Tedania (Tedania) Stylonychaeta against Methicillin Resistant Staphylococcus aureus. This is the first study done on some of the marine sponges and ascidians in the Phillip’s Reef, and therefore further evaluation of the purified compounds is necessary in order to obtain the identity of the pure compounds and possibly determine the mechanism of action, and synthesize structural analogues for further studies.
- Full Text:
- Date Issued: 2018
Factors influencing the hygienic quality of milk yield from smallholder dairy herds in the Eastern Cape Province, South Africa
- Authors: Dube, Hlengani Paul
- Date: 2018
- Subjects: Milk hygiene
- Language: English
- Type: Thesis , Masters , Animal Science
- Identifier: http://hdl.handle.net/10353/10790 , vital:35761
- Description: The objective of the study was to identify factors influencing the hygienic quality of milk of smallholder dairy herds in the Eastern Cape Province of South Africa. Three smallholder herds participating in the National Animal recording scheme and located in Alexandria and East London District Municipalities were used. 90 dairy animals from 3 farms were used, each farm consisting of 30 animals. Three breeds of ten animals were randomly chosen from each farm, the three breeds include, (Holstein, Jersey and Crosses), and four seasons, (autumn, winter, spring and summer) were used to determine the effects of breed and season on the hygienic quality of milk. Milk components included fat percentage, protein percentage, lactose percentage, milk urea nitrogen, milk yield and somatic cell counts (SCC). A total of 1080 milk samples were collected in the afternoon after milking. Procedure of general linear model of SAS was used to determine the effects of breed, season and farm of the milk quality parameters. Means were separated by PDIFF test (α = 0.05). Fixed effects of season, breed and farm, along with 2 way interactions of season and farm and breed and farm were determined. An evaluation template was used to identify the factors affecting hygienic quality of milk. Descriptive statistics (frequencies and percentages) were used. In order to investigate associations between variables of interest, a Pearson Chi-square test was done. The Chi-square test was also used to determine significantly independent findings at a P < 0.10 level of confidence. Cross tabulations were done to establish a basis for comparison and to find out if there is a relationship between two or more variables. The breeds kept within the smallholder dairy herds include Holstein, Jersey, Ayrshire, Guernsey and their Crosses. All farmers’practised pasture based dairy farming system, which includes exclusive dairy production and dairy with other animals like poultry and pigs. 33.33 percent of the smallholder herds use the machine milking method, while 66.67 percent use both the machine and hand milking methods. Milking time is uniform throughout the farms, with milking being done twice a day, in the morning and afternoon. The hygiene practices of the farms were largely similar from farm to farm. Before milking, the udders and teats of animals are washed with clean running water. After milking, the teats of the animals are dipped in teat dip to prevent mastitis. All the farmers’ dairy milking facilities have a permanent water source with continuous supply throughout the year. The water sources vary according to farms, with 33.33% use boreholes, while 66.67 percent utilise rivers and springs. Farmers face numerous challenges such as ageing and dilapidated equipment and infrastructure, limited capital that reduces the number of employees on farm and the purchase of feed inputs to support the milking procedure. Effect of season on milk quality, were significantly (P <0.001) different in milk yield, lactose, and somatic cell counts, and significant different at (P < 0.05) for milk urea nitrogen. High milk yields are observed in spring, and winter, while low milk yields are observed in autumn. High values for fat and protein content were observed in winter. High somatic cell counts were observed in autumn than in spring summer and winter. Effects of farm, on milk quality were significantly (P < 0.001) different on milk yield, fat, protein, lactose, and milk urea nitrogen, and significantly different (P < 0.01) for somatic cell counts. Milk yields varied from 14.03kg/day, 15.51kg/day, and 20.12kg/day, fat percentage varied from 4.52 percent, 4.36 percent, and 4.18 percent, protein percentages of 3.55 percent, 3.44 percent, and 3.47 percent, lactose percentage of 4.47 percent, 4.65 percent, and 4.69 percent, somatic cell counts of 588.42cells/ml, 308.90cells/ml, and 437.43cells/ml, and milk urea nitrogen of 9.84mg/100ml, 10.03mg/100ml, and 10.91mg/100ml for High heaven, Soqhayisa and Matshibele farms respectively. Effect of breed on milk quality, were significantly (P < 0.001) different for milk yield, fat and protein percentage. Milk yields amongst breeds varied at 15.57kg/day, 17.92kg/day, and 16.18kg/day, fat percentages of 4.51 percent, 4.18 percent, and 4.37 percent, protein percentages of 3.55 percent, 3.39 percent, and 3.52 percent, for Jersey, Holstein Cross bred breeds respectively. There were no differences in lactose percentage, somatic cell counts, and milk urea nitrogen amongst breeds. The interaction between farm and season had an effect on milk yield (P < 0.0004), lactose (P < 0.0001), somatic cell counts (P < 0.0001), milk urea nitrogen (P < 0.0019). Milk fat and protein had no effect of farm and season. The interaction between farm and breed had an effect on milk yield (P < 0.0018), fat (P < 0.0001), protein (P < 0.0001), lactose (P < 0.0227), milk urea nitrogen (P < 0.0373). Farm and breed had no effect onsomatic cell counts. The effect of the farm had a greater detrimental effect on the variations in milk composition within the season and the breed. Milk quality is mainly affected by the farm management practices which at times are affected by the farmer’s resources to achieve the basic routine activities for clean milk. Improving the hygienic practises such as udder cleaning, removal of feed from the troughs, and environmental sanitation will increase milk quality in smallholder herds. Smallholder dairy herds were able to meet the milk quality standards of low somatic cell counts that are acceptable as grade A milk.
- Full Text:
- Date Issued: 2018
- Authors: Dube, Hlengani Paul
- Date: 2018
- Subjects: Milk hygiene
- Language: English
- Type: Thesis , Masters , Animal Science
- Identifier: http://hdl.handle.net/10353/10790 , vital:35761
- Description: The objective of the study was to identify factors influencing the hygienic quality of milk of smallholder dairy herds in the Eastern Cape Province of South Africa. Three smallholder herds participating in the National Animal recording scheme and located in Alexandria and East London District Municipalities were used. 90 dairy animals from 3 farms were used, each farm consisting of 30 animals. Three breeds of ten animals were randomly chosen from each farm, the three breeds include, (Holstein, Jersey and Crosses), and four seasons, (autumn, winter, spring and summer) were used to determine the effects of breed and season on the hygienic quality of milk. Milk components included fat percentage, protein percentage, lactose percentage, milk urea nitrogen, milk yield and somatic cell counts (SCC). A total of 1080 milk samples were collected in the afternoon after milking. Procedure of general linear model of SAS was used to determine the effects of breed, season and farm of the milk quality parameters. Means were separated by PDIFF test (α = 0.05). Fixed effects of season, breed and farm, along with 2 way interactions of season and farm and breed and farm were determined. An evaluation template was used to identify the factors affecting hygienic quality of milk. Descriptive statistics (frequencies and percentages) were used. In order to investigate associations between variables of interest, a Pearson Chi-square test was done. The Chi-square test was also used to determine significantly independent findings at a P < 0.10 level of confidence. Cross tabulations were done to establish a basis for comparison and to find out if there is a relationship between two or more variables. The breeds kept within the smallholder dairy herds include Holstein, Jersey, Ayrshire, Guernsey and their Crosses. All farmers’practised pasture based dairy farming system, which includes exclusive dairy production and dairy with other animals like poultry and pigs. 33.33 percent of the smallholder herds use the machine milking method, while 66.67 percent use both the machine and hand milking methods. Milking time is uniform throughout the farms, with milking being done twice a day, in the morning and afternoon. The hygiene practices of the farms were largely similar from farm to farm. Before milking, the udders and teats of animals are washed with clean running water. After milking, the teats of the animals are dipped in teat dip to prevent mastitis. All the farmers’ dairy milking facilities have a permanent water source with continuous supply throughout the year. The water sources vary according to farms, with 33.33% use boreholes, while 66.67 percent utilise rivers and springs. Farmers face numerous challenges such as ageing and dilapidated equipment and infrastructure, limited capital that reduces the number of employees on farm and the purchase of feed inputs to support the milking procedure. Effect of season on milk quality, were significantly (P <0.001) different in milk yield, lactose, and somatic cell counts, and significant different at (P < 0.05) for milk urea nitrogen. High milk yields are observed in spring, and winter, while low milk yields are observed in autumn. High values for fat and protein content were observed in winter. High somatic cell counts were observed in autumn than in spring summer and winter. Effects of farm, on milk quality were significantly (P < 0.001) different on milk yield, fat, protein, lactose, and milk urea nitrogen, and significantly different (P < 0.01) for somatic cell counts. Milk yields varied from 14.03kg/day, 15.51kg/day, and 20.12kg/day, fat percentage varied from 4.52 percent, 4.36 percent, and 4.18 percent, protein percentages of 3.55 percent, 3.44 percent, and 3.47 percent, lactose percentage of 4.47 percent, 4.65 percent, and 4.69 percent, somatic cell counts of 588.42cells/ml, 308.90cells/ml, and 437.43cells/ml, and milk urea nitrogen of 9.84mg/100ml, 10.03mg/100ml, and 10.91mg/100ml for High heaven, Soqhayisa and Matshibele farms respectively. Effect of breed on milk quality, were significantly (P < 0.001) different for milk yield, fat and protein percentage. Milk yields amongst breeds varied at 15.57kg/day, 17.92kg/day, and 16.18kg/day, fat percentages of 4.51 percent, 4.18 percent, and 4.37 percent, protein percentages of 3.55 percent, 3.39 percent, and 3.52 percent, for Jersey, Holstein Cross bred breeds respectively. There were no differences in lactose percentage, somatic cell counts, and milk urea nitrogen amongst breeds. The interaction between farm and season had an effect on milk yield (P < 0.0004), lactose (P < 0.0001), somatic cell counts (P < 0.0001), milk urea nitrogen (P < 0.0019). Milk fat and protein had no effect of farm and season. The interaction between farm and breed had an effect on milk yield (P < 0.0018), fat (P < 0.0001), protein (P < 0.0001), lactose (P < 0.0227), milk urea nitrogen (P < 0.0373). Farm and breed had no effect onsomatic cell counts. The effect of the farm had a greater detrimental effect on the variations in milk composition within the season and the breed. Milk quality is mainly affected by the farm management practices which at times are affected by the farmer’s resources to achieve the basic routine activities for clean milk. Improving the hygienic practises such as udder cleaning, removal of feed from the troughs, and environmental sanitation will increase milk quality in smallholder herds. Smallholder dairy herds were able to meet the milk quality standards of low somatic cell counts that are acceptable as grade A milk.
- Full Text:
- Date Issued: 2018
Chemical transformation and phytochemical studies of bioactive constituents from extract of callistemon citrinus (curtis) skeels
- Authors: Larayetan, Rotimi Abisoye
- Date: 2018
- Subjects: Callistemon Wild flowers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9122 , vital:34272
- Description: Callistemon citrinus belongs to the family Myrtaceae and exhibits therapeutic activities. The aerial parts of this plant are used to treat different ailments, among them are parasitic infections. The leaves, flowers and stems of Callistemon citrinus were subjected to hydrodistillation. The oils collected were studied by GC-MS analysis for the essential constituents. The overall phenolic content of the leaves oil, radical scavenging, antibacterial action and antioxidant activities of the essential oils of Callistemon citrinus were determined using standard methods, with free radical DPPH or ABTS as reference antioxidants. Chemical transformation of the components was examined for a whole year. A relationship between the chemical change in the volatile oil constituents, antioxidant capacity, percentage yield of the oil of Callistemon citrinus and fluctuation in season has been established. Active phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus were determined spectrophotometrically. The antimicrobial properties, time of kill, and antioxidant activity of the extracts were explored. The bioactive components were characterized by high level of fatty acids. Squalene, a triterpenoid synthesized in human liver was obtained in the two extracts at varying amounts. The ethyl acetate extract demonstrated strong activity against P. aeruginosa ACC (28.7 ± 1.2 mm), Listeria ACC (26.0 ± 2.0 mm) and Escherichia coli ATCC 35150 (24.0 ± 3.5 mm). Qualitative phytochemical screening revealed the presence of alkaloids, glycosides, saponins, steroids and triterpenoids, fats and oils, flavonoids, phenols and tannins in them. In the quantitative phytochemical determination (total tannin, total flavonoids and flavonols, total phenolic and total antioxidant capacity) were carried out. The minimum time needed to kill the tested bacterial strains totally ranged from 15 to 24 hours. The aqueous extracts used for biosynthesis of nanoparticles were obtained from the fresh aerial parts of the plant. The biosynthesized gold and silver nanoparticles (AuNPs and AgNPs) of the aqueous extracts of the seed, flower and leaf of the plant, which are active as reducing and capping agents, were characterized using UV-VIS spectrophotometry, XRD, SEM, EDS, TEM, and FT IR. The XRD analysis revealed that the AgNPs were crystalline and the TEM showed that the shapes were spherical with an average size of 29 nm. For AuNPs, an average particle size of about 37 nm was confirmed by the TEM while the morphology and composition of the AuNPs were ascertained by SEM and EDS micrographs; uneven spherical shaped nanoparticles were established by the SEM. Both SEM and EDS demonstrated triangular shaped materials made up of silver and oxygen only. Absorption spectra confirmed by UV-VIS signify the dispersed nature of the synthesized nanoparticles with absorption band observed at 280 nm for the leaf AgNPs. FT IR had absorption bands at about 1700 cm-1 establishing the C=O stretching due to the amide bond while the FT IR for the AuNPs showed an absorption peak at 230 cm-1 confirming the presence of gold nanoparticles. The phytochemical investigation, isolation and characterization of the bioactive compounds of various organic crude extracts like hexane, dichloromethane, methanol and ethyl acetate were as well carried out, and the compounds responsible for their medicinal actions were determined. The results from different experiments revealed that the leaves and flowers of Callistemon citrinus possessed phenolic compounds and cyclic ethers with a variety of pharmacological action. The ethyl acetate and methanol crude extracts were found to possess broad spectrum of antimicrobial activities and pharmaceutically essential bioactive components with striking antioxidant capacities that may be used in the synthesis of novel drugs for the management of different ailments. The AuNPs and AgNPs synthesized from the seed, flower and leaf extracts of Callistemon citrinus where found to have prominent antimalarial, antiplasmodial, and antibacterial activities. The biosynthesized nanoparticles inhibit all the bacterial strains used and they were not cytotoxic to Hela cells, confirming their prospect for use as an excellent source for naturally occurring drugs against malaria, cell cytotoxicity, trypanosomes, and microbial infection. Similarly the crude organic extracts and the fractions derived from them exhibited high antimalarial and antitrypanosomal activities, but they were toxic to Hela cells. This is an indication that they will not be safe for use as targeted drugs for mammalian organism.
- Full Text:
- Date Issued: 2018
- Authors: Larayetan, Rotimi Abisoye
- Date: 2018
- Subjects: Callistemon Wild flowers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9122 , vital:34272
- Description: Callistemon citrinus belongs to the family Myrtaceae and exhibits therapeutic activities. The aerial parts of this plant are used to treat different ailments, among them are parasitic infections. The leaves, flowers and stems of Callistemon citrinus were subjected to hydrodistillation. The oils collected were studied by GC-MS analysis for the essential constituents. The overall phenolic content of the leaves oil, radical scavenging, antibacterial action and antioxidant activities of the essential oils of Callistemon citrinus were determined using standard methods, with free radical DPPH or ABTS as reference antioxidants. Chemical transformation of the components was examined for a whole year. A relationship between the chemical change in the volatile oil constituents, antioxidant capacity, percentage yield of the oil of Callistemon citrinus and fluctuation in season has been established. Active phytochemicals present in both ethyl acetate and methanolic extracts of Callistemon citrinus were determined spectrophotometrically. The antimicrobial properties, time of kill, and antioxidant activity of the extracts were explored. The bioactive components were characterized by high level of fatty acids. Squalene, a triterpenoid synthesized in human liver was obtained in the two extracts at varying amounts. The ethyl acetate extract demonstrated strong activity against P. aeruginosa ACC (28.7 ± 1.2 mm), Listeria ACC (26.0 ± 2.0 mm) and Escherichia coli ATCC 35150 (24.0 ± 3.5 mm). Qualitative phytochemical screening revealed the presence of alkaloids, glycosides, saponins, steroids and triterpenoids, fats and oils, flavonoids, phenols and tannins in them. In the quantitative phytochemical determination (total tannin, total flavonoids and flavonols, total phenolic and total antioxidant capacity) were carried out. The minimum time needed to kill the tested bacterial strains totally ranged from 15 to 24 hours. The aqueous extracts used for biosynthesis of nanoparticles were obtained from the fresh aerial parts of the plant. The biosynthesized gold and silver nanoparticles (AuNPs and AgNPs) of the aqueous extracts of the seed, flower and leaf of the plant, which are active as reducing and capping agents, were characterized using UV-VIS spectrophotometry, XRD, SEM, EDS, TEM, and FT IR. The XRD analysis revealed that the AgNPs were crystalline and the TEM showed that the shapes were spherical with an average size of 29 nm. For AuNPs, an average particle size of about 37 nm was confirmed by the TEM while the morphology and composition of the AuNPs were ascertained by SEM and EDS micrographs; uneven spherical shaped nanoparticles were established by the SEM. Both SEM and EDS demonstrated triangular shaped materials made up of silver and oxygen only. Absorption spectra confirmed by UV-VIS signify the dispersed nature of the synthesized nanoparticles with absorption band observed at 280 nm for the leaf AgNPs. FT IR had absorption bands at about 1700 cm-1 establishing the C=O stretching due to the amide bond while the FT IR for the AuNPs showed an absorption peak at 230 cm-1 confirming the presence of gold nanoparticles. The phytochemical investigation, isolation and characterization of the bioactive compounds of various organic crude extracts like hexane, dichloromethane, methanol and ethyl acetate were as well carried out, and the compounds responsible for their medicinal actions were determined. The results from different experiments revealed that the leaves and flowers of Callistemon citrinus possessed phenolic compounds and cyclic ethers with a variety of pharmacological action. The ethyl acetate and methanol crude extracts were found to possess broad spectrum of antimicrobial activities and pharmaceutically essential bioactive components with striking antioxidant capacities that may be used in the synthesis of novel drugs for the management of different ailments. The AuNPs and AgNPs synthesized from the seed, flower and leaf extracts of Callistemon citrinus where found to have prominent antimalarial, antiplasmodial, and antibacterial activities. The biosynthesized nanoparticles inhibit all the bacterial strains used and they were not cytotoxic to Hela cells, confirming their prospect for use as an excellent source for naturally occurring drugs against malaria, cell cytotoxicity, trypanosomes, and microbial infection. Similarly the crude organic extracts and the fractions derived from them exhibited high antimalarial and antitrypanosomal activities, but they were toxic to Hela cells. This is an indication that they will not be safe for use as targeted drugs for mammalian organism.
- Full Text:
- Date Issued: 2018
Investigation of strategies employed in rural households to improve food security in Raymond Mhlaba Local Municipality : a case of Zihlahleni Location in Middledrift, Eastern Cape Province
- Authors: Gqozo, Odwa
- Date: 2018
- Subjects: Food security -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10758 , vital:35752
- Description: Eastern Cape is one of the provinces experiencing a rapid increase in food prices while household income is increasing at a slower rate. Against this background, the main objective of this study was to investigate strategies used by rural households to improve food security in Raymond Mhlaba Local Municipality formally known as Nkonkobe in the Eastern Cape Province, South Africa. Data were collected from 100 households using a questionnaire as the main instrument by using simple random sampling. Data were analyzed by employing simple descriptive statistics to describe household food security. Results revealed that most (50.3percent) households that were interviewed were male headed and unemployment was high (73.6percent). Moreover, the average age of the interviewed household heads was 59 years. Most (68percent) of the households owned home gardens and had access to arable land which was not being cultivated. Most (87percent) households indicated that lack of capital was the main cause of food security and depended on government grants. Most (100percent) of the interviewed household heads depend mostly on food purchases rather than their own production. The recommendation is that the government should continue fostering its agenda of improving agriculture as a strategy in rural households for curbing food insecurity.
- Full Text:
- Date Issued: 2018
- Authors: Gqozo, Odwa
- Date: 2018
- Subjects: Food security -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10758 , vital:35752
- Description: Eastern Cape is one of the provinces experiencing a rapid increase in food prices while household income is increasing at a slower rate. Against this background, the main objective of this study was to investigate strategies used by rural households to improve food security in Raymond Mhlaba Local Municipality formally known as Nkonkobe in the Eastern Cape Province, South Africa. Data were collected from 100 households using a questionnaire as the main instrument by using simple random sampling. Data were analyzed by employing simple descriptive statistics to describe household food security. Results revealed that most (50.3percent) households that were interviewed were male headed and unemployment was high (73.6percent). Moreover, the average age of the interviewed household heads was 59 years. Most (68percent) of the households owned home gardens and had access to arable land which was not being cultivated. Most (87percent) households indicated that lack of capital was the main cause of food security and depended on government grants. Most (100percent) of the interviewed household heads depend mostly on food purchases rather than their own production. The recommendation is that the government should continue fostering its agenda of improving agriculture as a strategy in rural households for curbing food insecurity.
- Full Text:
- Date Issued: 2018
Ruthenium (II) complexes of mixed bipyridyl and dithiolate/thiourea ligands :|bsynthesis, characterization, photophysical and electrochemical studies
- Authors: Nkombi, Pelokazi
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds Ligands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10134 , vital:35358
- Description: Energy is one of the most important factor to influence human lives. The increased in energy demand as well as the detrimental effects posed by emission of greenhouse gases due to continue use of fossil fuels for electricity generation has led to a renewed focus on energy production using renewable energy sources which are relatively cheap, clean and environmentally sustainable. Among the various renewable energy sources used so far, the Dye Synthesized Solar Cells (DSSCs), a form of photovoltaic device is reported for their better efficiencies despite their low cost of production and ability to work relatively under low light conditions. A recent report on the solar-to-electricity conversion efficiency of a typical DSSC sensitizer made from zinc based porphyrin dye coupled with sintered titanium(IV) oxide as semiconductor was 13 percent. In this study, 2,2-bipyridyl-4,4-dicarboxylic acid (bpydc) was used as mixed ligand and four dithiolate ligands; L1 = dipotassium ethoxycarbonyl-1-cyanoethylene-2,2-dithiolate, L2 = dipotassium bis(ethoxycarbonyl)ethane-2,2-dithiolate, L3 = dipotassium cyanodithio imidocarbonate and L4 = dipotassium 2,2-dicyanoethylene-2,2-dithiolate were synthesized while four alkyl thiourea ligands, L5 = 1,3-dimethyl thiourea, L6 = 1,3-diethyl thiourea, L7 = 1,3-diisopropyl thiourea and L8 = 1-methyl thiourea were purchased and used as supplied without further purification. These ligands were used to prepare eight ruthenium(II) complexes of mixed bipyridyl/dithiolate/thiourea. The compounds were characterised by elemental analysis and spectroscopic techniques, namely: Fourier transform infrared (FTIR), Nuclear Magnetic Resonance (NMR), ultraviolet-visible and photoluminescence (PL). Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used for the electrochemical studies. Photoluminescence and UV-Vis spectroscopies were used for geometric and photophysical studies of the complexes respectively. FTIR spectra confirmed presence of functional groups in ligands and coordination of these ligands to ruthenium(II) ions to form complexes. The UV-Vis confirmed that the Ru(II) dithiolene complexes exhibited square planar geometries while the Ru(II) thiourea complexes gave octahedral geometries, this was deduced from the transitions assigned to the complexes. All the ruthenium(II) complexes synthesized showed photoluminescence properties that are suitable for light harvesting and application for dye-sensitized solar cells. Cyclic and square wave voltammetry show Ru(II) thiourea complexes have better redox properties when compared to Ru(II) dithiolate complexes which is ascribed to ligand strength field possibly due to contribution from the two bonded NCS groups.
- Full Text:
- Date Issued: 2018
- Authors: Nkombi, Pelokazi
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds Ligands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10134 , vital:35358
- Description: Energy is one of the most important factor to influence human lives. The increased in energy demand as well as the detrimental effects posed by emission of greenhouse gases due to continue use of fossil fuels for electricity generation has led to a renewed focus on energy production using renewable energy sources which are relatively cheap, clean and environmentally sustainable. Among the various renewable energy sources used so far, the Dye Synthesized Solar Cells (DSSCs), a form of photovoltaic device is reported for their better efficiencies despite their low cost of production and ability to work relatively under low light conditions. A recent report on the solar-to-electricity conversion efficiency of a typical DSSC sensitizer made from zinc based porphyrin dye coupled with sintered titanium(IV) oxide as semiconductor was 13 percent. In this study, 2,2-bipyridyl-4,4-dicarboxylic acid (bpydc) was used as mixed ligand and four dithiolate ligands; L1 = dipotassium ethoxycarbonyl-1-cyanoethylene-2,2-dithiolate, L2 = dipotassium bis(ethoxycarbonyl)ethane-2,2-dithiolate, L3 = dipotassium cyanodithio imidocarbonate and L4 = dipotassium 2,2-dicyanoethylene-2,2-dithiolate were synthesized while four alkyl thiourea ligands, L5 = 1,3-dimethyl thiourea, L6 = 1,3-diethyl thiourea, L7 = 1,3-diisopropyl thiourea and L8 = 1-methyl thiourea were purchased and used as supplied without further purification. These ligands were used to prepare eight ruthenium(II) complexes of mixed bipyridyl/dithiolate/thiourea. The compounds were characterised by elemental analysis and spectroscopic techniques, namely: Fourier transform infrared (FTIR), Nuclear Magnetic Resonance (NMR), ultraviolet-visible and photoluminescence (PL). Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used for the electrochemical studies. Photoluminescence and UV-Vis spectroscopies were used for geometric and photophysical studies of the complexes respectively. FTIR spectra confirmed presence of functional groups in ligands and coordination of these ligands to ruthenium(II) ions to form complexes. The UV-Vis confirmed that the Ru(II) dithiolene complexes exhibited square planar geometries while the Ru(II) thiourea complexes gave octahedral geometries, this was deduced from the transitions assigned to the complexes. All the ruthenium(II) complexes synthesized showed photoluminescence properties that are suitable for light harvesting and application for dye-sensitized solar cells. Cyclic and square wave voltammetry show Ru(II) thiourea complexes have better redox properties when compared to Ru(II) dithiolate complexes which is ascribed to ligand strength field possibly due to contribution from the two bonded NCS groups.
- Full Text:
- Date Issued: 2018
Assessment of the human health implications of climate variability in East London, Eastern Cape, South Africa
- Orimoloye, Israel Ropo https://orcid.org/0000-0001-5058-2799
- Authors: Orimoloye, Israel Ropo https://orcid.org/0000-0001-5058-2799
- Date: 2018
- Subjects: Climatic changes http://id.loc.gov/authorities/subjects/sh85027037
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19715 , vital:43171
- Description: Impacts associated with climate variability and extreme heat are already obvious in varying degrees and expected to be disruptive in the near future across the globe especially in the urban regions. Urban areas have distinctive features that leave their residents and properties vulnerable to extreme climate events. Global temperatures continue to change, reaching new levels almost every year for the past two decades. However, even though the causes are debated it is evident that climate variability is real. Climate variability and disaster risk are threats to human health that adversely reinforce each other. Better knowledge on the association between climate change, variability and extreme weather-related illness is needed and can aid strategies to reduce vulnerabilities. The impacts of climate variability on the health of residents in East London (EL) area in the Eastern Cape Province, South Africa were explored through four interdependent research segments. The first section examined the climate variability and urban surface thermal characteristics implication on human health using Remote Sensing (RS) and Geographic Information System (GIS) techniques. Remote sensing was used to assess the Land Surface Temperature (LST) and estimated Radiation (R) of East London area from Landsat Thematic Mapper (TM) images for 1986, 1996, 2006 as well as from Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) for 2016 spanning a period of 30 years. Rapid urbanization and land cover changes in this area have contributed significantly to this drastic change in the natural land surface characteristics (increased land surface temperature and surface solar radiation). For instance, vegetation cover declined by about 358.812km2 while built-up areas increased by 175.473km2 during this period which correlates with the area thermal characteristics changes. Radiation levels also increased over the years with values exceeding the global solar radiation index. Exposure to increased surface radiation poses risks of heat stroke, skin cancer and heart disease to the local population. Consequently, this study provides pertinent information on human health sustainability and epidemiological case management. The second part explored past temperature and humidity trends (1986-2016) and projects future trends (2017-2030). The historical data of meteorological variables were obtained from the archives of the South African Weather Service and analyzed using the ordinary least square regression model in GRETL (GNU Regression Econometric and Time-series Library) statistical software. This study discovered a local consistency between models and the observations add to existing knowledge and this is crucial in knowing the shifts in climatic change as well as recognizing variability and its conflicting effects on human health, environment, agriculture, ecological sustainability and socioeconomic status in the region. The third segment assessed the potential impacts of climate variability on health using existing heat indices during the study period. The results demonstrated that in East London from 1986 to 2016 during summer and autumn (December to May) of various years exceeded high heat index values. It is obvious that summer and autumn months are more vulnerable to heat extreme and humidex. The humidex and Heat Index (HI) increased annually by 0.03 percent and 0.9 percent respectively throughout the study period. The increment in the various indices showed highly significant ill-health and environmental impacts on humans especially with prolonged exposure. The last segment appraised the association between climatic elements and epidemiological incidences of the study area between 2012 and 2016. The epidemiology incidences data were obtained from the archives of the Cecilia Makiwane Hospital in East London area and National Tertiary Service Grant (NTSG) database for the period. The results have showed that there exists significant effects of climate variability on the health of East London residents and these have been identified to have negative impacts on health of the people in the area. This study also revealed noticeable impacts of extreme heat on human health and a positive correlation between meteorological components (HI and temperature) and epidemiological cases (cardiovascular, skin cancer and diarrhea) during the study period. , Thesis (PhD) (Geography) -- University of Fort Hare, 2018
- Full Text:
- Date Issued: 2018
- Authors: Orimoloye, Israel Ropo https://orcid.org/0000-0001-5058-2799
- Date: 2018
- Subjects: Climatic changes http://id.loc.gov/authorities/subjects/sh85027037
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19715 , vital:43171
- Description: Impacts associated with climate variability and extreme heat are already obvious in varying degrees and expected to be disruptive in the near future across the globe especially in the urban regions. Urban areas have distinctive features that leave their residents and properties vulnerable to extreme climate events. Global temperatures continue to change, reaching new levels almost every year for the past two decades. However, even though the causes are debated it is evident that climate variability is real. Climate variability and disaster risk are threats to human health that adversely reinforce each other. Better knowledge on the association between climate change, variability and extreme weather-related illness is needed and can aid strategies to reduce vulnerabilities. The impacts of climate variability on the health of residents in East London (EL) area in the Eastern Cape Province, South Africa were explored through four interdependent research segments. The first section examined the climate variability and urban surface thermal characteristics implication on human health using Remote Sensing (RS) and Geographic Information System (GIS) techniques. Remote sensing was used to assess the Land Surface Temperature (LST) and estimated Radiation (R) of East London area from Landsat Thematic Mapper (TM) images for 1986, 1996, 2006 as well as from Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) for 2016 spanning a period of 30 years. Rapid urbanization and land cover changes in this area have contributed significantly to this drastic change in the natural land surface characteristics (increased land surface temperature and surface solar radiation). For instance, vegetation cover declined by about 358.812km2 while built-up areas increased by 175.473km2 during this period which correlates with the area thermal characteristics changes. Radiation levels also increased over the years with values exceeding the global solar radiation index. Exposure to increased surface radiation poses risks of heat stroke, skin cancer and heart disease to the local population. Consequently, this study provides pertinent information on human health sustainability and epidemiological case management. The second part explored past temperature and humidity trends (1986-2016) and projects future trends (2017-2030). The historical data of meteorological variables were obtained from the archives of the South African Weather Service and analyzed using the ordinary least square regression model in GRETL (GNU Regression Econometric and Time-series Library) statistical software. This study discovered a local consistency between models and the observations add to existing knowledge and this is crucial in knowing the shifts in climatic change as well as recognizing variability and its conflicting effects on human health, environment, agriculture, ecological sustainability and socioeconomic status in the region. The third segment assessed the potential impacts of climate variability on health using existing heat indices during the study period. The results demonstrated that in East London from 1986 to 2016 during summer and autumn (December to May) of various years exceeded high heat index values. It is obvious that summer and autumn months are more vulnerable to heat extreme and humidex. The humidex and Heat Index (HI) increased annually by 0.03 percent and 0.9 percent respectively throughout the study period. The increment in the various indices showed highly significant ill-health and environmental impacts on humans especially with prolonged exposure. The last segment appraised the association between climatic elements and epidemiological incidences of the study area between 2012 and 2016. The epidemiology incidences data were obtained from the archives of the Cecilia Makiwane Hospital in East London area and National Tertiary Service Grant (NTSG) database for the period. The results have showed that there exists significant effects of climate variability on the health of East London residents and these have been identified to have negative impacts on health of the people in the area. This study also revealed noticeable impacts of extreme heat on human health and a positive correlation between meteorological components (HI and temperature) and epidemiological cases (cardiovascular, skin cancer and diarrhea) during the study period. , Thesis (PhD) (Geography) -- University of Fort Hare, 2018
- Full Text:
- Date Issued: 2018
Investigation of the subsurface geology using time domain, magnetic and electrical resistivity geophysical techniques in the Karoo basin at Beaufort west, Western Cape Province, South Africa
- Authors: Ntunja, Asanda
- Date: 2018
- Subjects: Geology Geophysics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14659 , vital:40034
- Description: Beaufort West lies in the Central Karoo Basin and is specifically situated in the Poortjie Member of the Teekloof Formation in the Beaufort Group. The Teekloof Formation was deposited in a floodplain environment and it consists of alternating bluish grey mudstone and very fine to medium grained sandstone. The sediments of the Karoo Basin were intruded by numerous dolerite sills and dykes during a period of extensive magmatic activity over the whole South African subcontinent when the break-up of Gondwanda occurred. This led to a continuous jointing of the sedimentary rocks and the jointing resulted in rocks that are prone to weathering. Weathering that occurred in Beaufort West resulted in the formation of alluvium, calcrete, scree and hard pan deposits which overlay most of the ground surface. The joints in rocks paved way for groundwater storage in the sedimentary beds as sediments of the Karoo Basin lack significant primary porosity. Geophysical surveys were done in order to determine a suitable site to locate and drill a deep borehole to the White Hill Formation in order to extract shale gas that is proposed to be present in the area, thereafter determine sites for monitoring boreholes for groundwater and also look for area where potential groundwater might be present. This then requires geophysical investigations of the surface and subsurface geology of the area prior to drilling so as to locate any features such as dolerite intrusions which may hinder the drilling process and locate shallow aquifers, which will tend to be monitored before and during fracking. Five lines of varying lengths from 2-6 km and different orientation were surveyed using geophysical techniques which included the time domain, electrical resistivity as well as the magnetic methods. The geophysical investigations were conducted in order to fulfil the main vii objectives and aims of the study. The techniques were then complemented by XRF, petrography and density analyses. The time domain method reveals that Lines 1 and Line 2 comprises of rocks with low resistivity values of less than 30 Ωm. These two lines were more conductive towards the east and northeast side of the study site and the resistivity tends to increase towards the south and west. Line 4 appeared to be more conductive towards the south-east of the line. Lines 3 and 5 showed high resistivity values with Line 5 being the most resistive suggesting that the underlying strata is consolidated, dry and hard. The resistivity in all the lines surveyed showed an increase with increasing depth. The depth of investigation was approximately up to 150 m. The electrical resistivity results were only obtained from Line 1 and Line 2. The results, which complement the time domain results, suggest that the two lines indeed comprise of rocks which exhibit low resistivity values. This then implies that the rocks in the vicinity are fractured and the fractures might be field with groundwater and possibly contain some conductive minerals such as sodium oxide (Na2O) as supported by XRF results. This method also reveals that along Line 1, there are individual bodies of high resistivity values. The probing depth of about 78 m was achieved for the electrical resistivity survey. The magnetic data indicate that the magnetic intensity does not vary much across lines 3, 4 and 5 and there is not much change in lithology with depth and lateral extent. The area covered by Lines 1 and 2, and the additional eleven fill in lines has several prominent magnetic highs that are inferred to be due to dolerite intrusions in the sandstones and these bodies may be connected at depth. One of these anomalies which trends east-west direction partially coincides with a mapped dolerite intrusion. Some areas with sandstones also exhibit high viii magnetism which is due to about 3.3% content of Fe2O3 present in the sandstones as seen from XRF. This is probably resulted from weathering of magnetite in dolerite intrusions. Petrography results obtained from samples collected in the field reveal that there is an abundance of quartz in sandstones and siltstones. Quartz arenite also contained about 50% of feldspar, containing both plagioclase and K-feldspar. The sandstones of the Teekloof Formation (Beaufort West) have undergone calcite replacement where the calcite matrix replaced most or all of the clay matrix between the mineral grains. The fractures in rocks were seen and it was inferred that they are due to the present cleavages in feldspar and weathering of feldspar in sandstones. Through X-ray Fluorescence (XRF) analysis, it was revealed that the rocks contained a high percentage of Na2O. XRF also showed that these rocks were under low chemical weathering which led to the formation of new minerals in rock as other minerals such as feldspar weather away. This resulted in quartz being the most dominant mineral present as it is not prone to chemical weathering and thus the rocks were proven to be chemically matured. Thirty one rock samples were collected from the field in order to determine the density and porosity measurements. The fine to medium grained grey sandstones show an average density of 2.597 g/cm3 and a porosity of 1.4 %. The brownish grey sandstone have an average density of 2.546 g/cm3 and porosity of 2.9 % and the brown sandstones exhibit an average of 2.584 g/cm3 and a porosity 1.46 %. Dolerite has an average density of 2.970 g/cm3 and porosity of 0.5 % and siltstones have a density of 2.595 g/cm3 and porosity of 1.38 %. The brownish grey sandstones have the highest porosity and the grey sandstone and siltstone have the least porosity after the dolerite.
- Full Text:
- Date Issued: 2018
- Authors: Ntunja, Asanda
- Date: 2018
- Subjects: Geology Geophysics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14659 , vital:40034
- Description: Beaufort West lies in the Central Karoo Basin and is specifically situated in the Poortjie Member of the Teekloof Formation in the Beaufort Group. The Teekloof Formation was deposited in a floodplain environment and it consists of alternating bluish grey mudstone and very fine to medium grained sandstone. The sediments of the Karoo Basin were intruded by numerous dolerite sills and dykes during a period of extensive magmatic activity over the whole South African subcontinent when the break-up of Gondwanda occurred. This led to a continuous jointing of the sedimentary rocks and the jointing resulted in rocks that are prone to weathering. Weathering that occurred in Beaufort West resulted in the formation of alluvium, calcrete, scree and hard pan deposits which overlay most of the ground surface. The joints in rocks paved way for groundwater storage in the sedimentary beds as sediments of the Karoo Basin lack significant primary porosity. Geophysical surveys were done in order to determine a suitable site to locate and drill a deep borehole to the White Hill Formation in order to extract shale gas that is proposed to be present in the area, thereafter determine sites for monitoring boreholes for groundwater and also look for area where potential groundwater might be present. This then requires geophysical investigations of the surface and subsurface geology of the area prior to drilling so as to locate any features such as dolerite intrusions which may hinder the drilling process and locate shallow aquifers, which will tend to be monitored before and during fracking. Five lines of varying lengths from 2-6 km and different orientation were surveyed using geophysical techniques which included the time domain, electrical resistivity as well as the magnetic methods. The geophysical investigations were conducted in order to fulfil the main vii objectives and aims of the study. The techniques were then complemented by XRF, petrography and density analyses. The time domain method reveals that Lines 1 and Line 2 comprises of rocks with low resistivity values of less than 30 Ωm. These two lines were more conductive towards the east and northeast side of the study site and the resistivity tends to increase towards the south and west. Line 4 appeared to be more conductive towards the south-east of the line. Lines 3 and 5 showed high resistivity values with Line 5 being the most resistive suggesting that the underlying strata is consolidated, dry and hard. The resistivity in all the lines surveyed showed an increase with increasing depth. The depth of investigation was approximately up to 150 m. The electrical resistivity results were only obtained from Line 1 and Line 2. The results, which complement the time domain results, suggest that the two lines indeed comprise of rocks which exhibit low resistivity values. This then implies that the rocks in the vicinity are fractured and the fractures might be field with groundwater and possibly contain some conductive minerals such as sodium oxide (Na2O) as supported by XRF results. This method also reveals that along Line 1, there are individual bodies of high resistivity values. The probing depth of about 78 m was achieved for the electrical resistivity survey. The magnetic data indicate that the magnetic intensity does not vary much across lines 3, 4 and 5 and there is not much change in lithology with depth and lateral extent. The area covered by Lines 1 and 2, and the additional eleven fill in lines has several prominent magnetic highs that are inferred to be due to dolerite intrusions in the sandstones and these bodies may be connected at depth. One of these anomalies which trends east-west direction partially coincides with a mapped dolerite intrusion. Some areas with sandstones also exhibit high viii magnetism which is due to about 3.3% content of Fe2O3 present in the sandstones as seen from XRF. This is probably resulted from weathering of magnetite in dolerite intrusions. Petrography results obtained from samples collected in the field reveal that there is an abundance of quartz in sandstones and siltstones. Quartz arenite also contained about 50% of feldspar, containing both plagioclase and K-feldspar. The sandstones of the Teekloof Formation (Beaufort West) have undergone calcite replacement where the calcite matrix replaced most or all of the clay matrix between the mineral grains. The fractures in rocks were seen and it was inferred that they are due to the present cleavages in feldspar and weathering of feldspar in sandstones. Through X-ray Fluorescence (XRF) analysis, it was revealed that the rocks contained a high percentage of Na2O. XRF also showed that these rocks were under low chemical weathering which led to the formation of new minerals in rock as other minerals such as feldspar weather away. This resulted in quartz being the most dominant mineral present as it is not prone to chemical weathering and thus the rocks were proven to be chemically matured. Thirty one rock samples were collected from the field in order to determine the density and porosity measurements. The fine to medium grained grey sandstones show an average density of 2.597 g/cm3 and a porosity of 1.4 %. The brownish grey sandstone have an average density of 2.546 g/cm3 and porosity of 2.9 % and the brown sandstones exhibit an average of 2.584 g/cm3 and a porosity 1.46 %. Dolerite has an average density of 2.970 g/cm3 and porosity of 0.5 % and siltstones have a density of 2.595 g/cm3 and porosity of 1.38 %. The brownish grey sandstones have the highest porosity and the grey sandstone and siltstone have the least porosity after the dolerite.
- Full Text:
- Date Issued: 2018
In silico analysis, isolation and kinetic characterisation of red algae (Rhodophyta) catalases
- Authors: Nodangala, Sinovuyo
- Date: 2018
- Subjects: Red algae Marine algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14626 , vital:40024
- Description: Catalase (EC: 1.11.1.6) is produced by almost all aerobic organism ranging from bacteria to human and is an essential antioxidant enzyme that catalyses the conversion of hydrogen peroxide to water and molecular oxygen, therefore neutralising hydrogen peroxide toxicity. The present study aimed to purify and characterise catalase from Pachymenia orbitosa, a marine red algae found in the Algoa Bay region of South Africa. Bioinformatics analysis was performed to confirm the presence of a catalase gene in the red algae genome. In silico analysis of the Chondrus crispus genome was performed to predict the functional and structural characterisation of the protein encoded by the gene. The Pachymenia orbitosa catalase enzyme was purified to homogeneity using 60% ammonium sulphate precipitation and Sephacryl S-200 gel filtration chromatography. InterProScan confirmed that the Chondrus crispus genome encodes a catalase protein, which is from the mono-functional and heme-dependent catalase-like superfamily. The purified Pachymenia orbitosa catalase enzyme displayed a specific activity of 23 000 units per mg of protein with a 14.94% recovery and 222.91 fold purification. Sodium dodecyl sulphatepolyacrylamide gel electrophoresis indicated a single band, with a molecular weight of around 50kDa. The catalase enzyme exhibited a maximum activity at pH 7 and a temperature of 30℃. It was stable up to 40℃ and rapidly denatured at temperatures above this. The Km and Vmax values for the purified catalase, using hydrogen peroxide as a substrate, were determined from the Lineweaver-Burk plot to be 22.22mM and 1.11x10-4mM.min-1 , respectively, while from the Hanes-Woolf plot, to be 23.4mM and 1.17x10-4mM.min-1 , respectively. The Heme catalase inhibitor (ferricyanide) inhibited the enzyme activity markedly, while sodium chloride and citric acid had only a slight inhibitory effect. Copper sulphate showed a slight stimulatory effect. The physiochemical properties suggest a good application potential in both the pharmaceutical and food industries
- Full Text:
- Date Issued: 2018
- Authors: Nodangala, Sinovuyo
- Date: 2018
- Subjects: Red algae Marine algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14626 , vital:40024
- Description: Catalase (EC: 1.11.1.6) is produced by almost all aerobic organism ranging from bacteria to human and is an essential antioxidant enzyme that catalyses the conversion of hydrogen peroxide to water and molecular oxygen, therefore neutralising hydrogen peroxide toxicity. The present study aimed to purify and characterise catalase from Pachymenia orbitosa, a marine red algae found in the Algoa Bay region of South Africa. Bioinformatics analysis was performed to confirm the presence of a catalase gene in the red algae genome. In silico analysis of the Chondrus crispus genome was performed to predict the functional and structural characterisation of the protein encoded by the gene. The Pachymenia orbitosa catalase enzyme was purified to homogeneity using 60% ammonium sulphate precipitation and Sephacryl S-200 gel filtration chromatography. InterProScan confirmed that the Chondrus crispus genome encodes a catalase protein, which is from the mono-functional and heme-dependent catalase-like superfamily. The purified Pachymenia orbitosa catalase enzyme displayed a specific activity of 23 000 units per mg of protein with a 14.94% recovery and 222.91 fold purification. Sodium dodecyl sulphatepolyacrylamide gel electrophoresis indicated a single band, with a molecular weight of around 50kDa. The catalase enzyme exhibited a maximum activity at pH 7 and a temperature of 30℃. It was stable up to 40℃ and rapidly denatured at temperatures above this. The Km and Vmax values for the purified catalase, using hydrogen peroxide as a substrate, were determined from the Lineweaver-Burk plot to be 22.22mM and 1.11x10-4mM.min-1 , respectively, while from the Hanes-Woolf plot, to be 23.4mM and 1.17x10-4mM.min-1 , respectively. The Heme catalase inhibitor (ferricyanide) inhibited the enzyme activity markedly, while sodium chloride and citric acid had only a slight inhibitory effect. Copper sulphate showed a slight stimulatory effect. The physiochemical properties suggest a good application potential in both the pharmaceutical and food industries
- Full Text:
- Date Issued: 2018
Dynamic Mathematical Modeling in Chemical Reaction Networks
- Authors: Gurajena, Simba
- Date: 2018
- Subjects: Chemical reaction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/11961 , vital:39122
- Description: Many students are familiar with the idea of ecological, financial modeling and modeling in other fields, but modeling in engineering fields is still an area to be looked at. In this discussion the researcher will deal with chemical reaction networks. This will cover areas in chemical reaction, interaction diagrams and the associated models. The discussion will also cover dynamic behaviour of reaction networks. The law of mass action and examples of simple networks will be dealt with. Differential equation models of biochemical and genetic systems are invariantly nonlinear, and as such numerical simulation is used to solve such models. The use of numerical simulation packages will be discussed and separation of timescale and model reduction will form part of the discussion.
- Full Text:
- Date Issued: 2018
- Authors: Gurajena, Simba
- Date: 2018
- Subjects: Chemical reaction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/11961 , vital:39122
- Description: Many students are familiar with the idea of ecological, financial modeling and modeling in other fields, but modeling in engineering fields is still an area to be looked at. In this discussion the researcher will deal with chemical reaction networks. This will cover areas in chemical reaction, interaction diagrams and the associated models. The discussion will also cover dynamic behaviour of reaction networks. The law of mass action and examples of simple networks will be dealt with. Differential equation models of biochemical and genetic systems are invariantly nonlinear, and as such numerical simulation is used to solve such models. The use of numerical simulation packages will be discussed and separation of timescale and model reduction will form part of the discussion.
- Full Text:
- Date Issued: 2018
Influence of family structure on food security status of farming households in Alice, South Africa
- Authors: Ijila, Olusegun Jeremiah
- Date: 2018
- Subjects: Food security Families--South Africa--Eastern Cape Farms, Small
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/11537 , vital:39081
- Description: Achieving food security in sub-Saharan Africa remains a major challenge despite efforts made by a majority of the countries to reduce abject poverty and food insecurity. Just as these countries prioritized food security under the Millennium Development Goals (MDGs), they are equally putting it on top of the agenda under the Sustainable Development Goals (SDGs). In the face of the political and economic developments seen in the country since 1994, South Africa is overwhelmed by poverty and unemployment. But efforts to address these problems have not given due recognition to the question of family structure which is complex and varied, with immense potential implications for ownership and distribution of resources and the bargaining strength that are likely to determine the food security status of various farming households. Furthermore, the contribution of households towards agricultural production differs according to the way family organizes itself. This study was carried out to determine the influence of family structures on food security status of farming households in Alice, South Africa. Data were collected from 120 farming households’ selected using purposive sampling method. To collect data, a well-structured questionnaire was administered through face-to-face interviews. Consequent to that, the data were analyzed using descriptive statistics, and binary logistic regression model. The dominant family structures are nuclear, single-parent, working parent and cohabiting. The analysis revealed that nuclear family where father, mother and their children have access to labour and financial resources could be more comfortable than single parent family. Working parents would probably be more food secure because both parents are able to combine incomes while food insecurity might exist within cohabiting families since the union is less stable because of scarce resources occasioned by their inability to combine their resources to pursue a common goal. The results further revealed that single parent family structures and socio-economic characteristics like age, marital status and year of education of the household head were significant in terms of their influence on food security. The study therefore, recommends that old people should be encouraged to participate in agricultural production due to the wealth of experience gathered over the years. It is probably safe to conclude that encouraging marriage would provide better opportunities to raise the necessary capital to support positive productivity changes that would have implications for enhanced food availability and affordability.
- Full Text:
- Date Issued: 2018
- Authors: Ijila, Olusegun Jeremiah
- Date: 2018
- Subjects: Food security Families--South Africa--Eastern Cape Farms, Small
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/11537 , vital:39081
- Description: Achieving food security in sub-Saharan Africa remains a major challenge despite efforts made by a majority of the countries to reduce abject poverty and food insecurity. Just as these countries prioritized food security under the Millennium Development Goals (MDGs), they are equally putting it on top of the agenda under the Sustainable Development Goals (SDGs). In the face of the political and economic developments seen in the country since 1994, South Africa is overwhelmed by poverty and unemployment. But efforts to address these problems have not given due recognition to the question of family structure which is complex and varied, with immense potential implications for ownership and distribution of resources and the bargaining strength that are likely to determine the food security status of various farming households. Furthermore, the contribution of households towards agricultural production differs according to the way family organizes itself. This study was carried out to determine the influence of family structures on food security status of farming households in Alice, South Africa. Data were collected from 120 farming households’ selected using purposive sampling method. To collect data, a well-structured questionnaire was administered through face-to-face interviews. Consequent to that, the data were analyzed using descriptive statistics, and binary logistic regression model. The dominant family structures are nuclear, single-parent, working parent and cohabiting. The analysis revealed that nuclear family where father, mother and their children have access to labour and financial resources could be more comfortable than single parent family. Working parents would probably be more food secure because both parents are able to combine incomes while food insecurity might exist within cohabiting families since the union is less stable because of scarce resources occasioned by their inability to combine their resources to pursue a common goal. The results further revealed that single parent family structures and socio-economic characteristics like age, marital status and year of education of the household head were significant in terms of their influence on food security. The study therefore, recommends that old people should be encouraged to participate in agricultural production due to the wealth of experience gathered over the years. It is probably safe to conclude that encouraging marriage would provide better opportunities to raise the necessary capital to support positive productivity changes that would have implications for enhanced food availability and affordability.
- Full Text:
- Date Issued: 2018
Synthesis, characterization and evaluation of photophysical and electrochemical properties of ruthenium(II) complexes for dye-sensitized solar cells
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
The classification of fuzzy groups of finite cyclic groups Zpn Zqm Zr and Zp1 Zp2 Zpn for distinct prime numbers p; q; r; p1; p2; ; pn and n;m 2 Z+
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
Appraisal of wastewater final effluents and river water as reservoirs of cholera and non-cholera causing vibrio species : case study of the Amatole and OR Tambo District Municipalities
- Authors: Nontongana, Nolonwabo
- Date: 2018
- Subjects: Vibrio -- South Africa -- Eastern Cape Vibrio cholerae Disease Reservoirs
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/9929 , vital:35146
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of inadequately treated wastewater effluents. This study was therefore designed to assess the occurrence of cholera and non-cholera causing Vibrio species in the final effluents of wastewater treatment plants and river waters in the Amatole (BT WWTP) and OR Tambo District municipalities (MT WWTP and QN River) of the Eastern Cape Province. Samples were collected monthly from December 2016 to November 2017 from the final effluent, 500 meters upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture-based and molecular techniques. Samples were collected aseptically using sterile 1L glass bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6hrs of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Antimicrobial susceptibility testing was done by the standard disc diffusion method recommended by the Clinical and Laboratory Standards Institute. The recovered Vibrio species were tested against a panel of 17 antibiotics. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chlorine (only for BT WWTP). Unacceptably high levels of the assayed parameters were observed in many cases for TDS (66 - 879 mg/l), turbidity (2.0 -722.33 NTU) and DO (2.5 – 9.7 mg/l) as well as chlorine (0.2 – 3.2 mg/L). Presumptive Vibrio densities varied from 2.91 to 3.91 log10 CFU/100 ml and 2.67 to 3.18 log CFU/100ml, for BT WWTP and MT WWTP respectively. The densities for the QN River ranged between 2.51 to 3.99 log10 CFU/100mL. Out of 720 presumptive isolates recovered, 619 (86 percent) were found to be positive for the Vibrio genus. Molecular confirmation of the presumptive Vibrio species revealed the presence of V. fluvialis (16), V. vulnificus (12), V aliginolyticus (9), V. parahaemolyticus (37) and V. cholerae (5) isolates were confirmed. The susceptibility against 17 different antibiotics by the recovered species were examined. V. cholerae was notably resistant against nalidixic acid (3) and Ampicilin (2), all the V. vulnificus isolates were resistant against ampicillin (16), V. fluvialis showed resistance against ciprofloxacin and nalidixic acid, all (9) isolates for V. alginolyticus were resistant against ampicillin. V. parahaemolyticus showed resistance against cefutoxime (16), cefuxime (8) and ampicillin (13). The recovery of Vibrio in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering that Vibrio are pathogenic bacteria. The findings of this study underline the need for constant monitoring of the physicochemical and microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works as this might pose adverse health risk to the communities which still rely heavily on these surface waters.
- Full Text:
- Date Issued: 2018
- Authors: Nontongana, Nolonwabo
- Date: 2018
- Subjects: Vibrio -- South Africa -- Eastern Cape Vibrio cholerae Disease Reservoirs
- Language: English
- Type: Thesis , Doctoral , Microbiology
- Identifier: http://hdl.handle.net/10353/9929 , vital:35146
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of inadequately treated wastewater effluents. This study was therefore designed to assess the occurrence of cholera and non-cholera causing Vibrio species in the final effluents of wastewater treatment plants and river waters in the Amatole (BT WWTP) and OR Tambo District municipalities (MT WWTP and QN River) of the Eastern Cape Province. Samples were collected monthly from December 2016 to November 2017 from the final effluent, 500 meters upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture-based and molecular techniques. Samples were collected aseptically using sterile 1L glass bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6hrs of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Antimicrobial susceptibility testing was done by the standard disc diffusion method recommended by the Clinical and Laboratory Standards Institute. The recovered Vibrio species were tested against a panel of 17 antibiotics. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chlorine (only for BT WWTP). Unacceptably high levels of the assayed parameters were observed in many cases for TDS (66 - 879 mg/l), turbidity (2.0 -722.33 NTU) and DO (2.5 – 9.7 mg/l) as well as chlorine (0.2 – 3.2 mg/L). Presumptive Vibrio densities varied from 2.91 to 3.91 log10 CFU/100 ml and 2.67 to 3.18 log CFU/100ml, for BT WWTP and MT WWTP respectively. The densities for the QN River ranged between 2.51 to 3.99 log10 CFU/100mL. Out of 720 presumptive isolates recovered, 619 (86 percent) were found to be positive for the Vibrio genus. Molecular confirmation of the presumptive Vibrio species revealed the presence of V. fluvialis (16), V. vulnificus (12), V aliginolyticus (9), V. parahaemolyticus (37) and V. cholerae (5) isolates were confirmed. The susceptibility against 17 different antibiotics by the recovered species were examined. V. cholerae was notably resistant against nalidixic acid (3) and Ampicilin (2), all the V. vulnificus isolates were resistant against ampicillin (16), V. fluvialis showed resistance against ciprofloxacin and nalidixic acid, all (9) isolates for V. alginolyticus were resistant against ampicillin. V. parahaemolyticus showed resistance against cefutoxime (16), cefuxime (8) and ampicillin (13). The recovery of Vibrio in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering that Vibrio are pathogenic bacteria. The findings of this study underline the need for constant monitoring of the physicochemical and microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works as this might pose adverse health risk to the communities which still rely heavily on these surface waters.
- Full Text:
- Date Issued: 2018
A Cost-Efficient Energy Management Model for ICT4D Platforms in Low Resource Communities
- Authors: Mbotoloshi, Dumisani
- Date: 2018
- Subjects: Information technology Communication in community development|
- Language: English
- Type: Thesis , Masters , MSc (Computer Science )
- Identifier: http://hdl.handle.net/10353/14538 , vital:39999
- Description: A couple of Information and Communication Technology (ICT) researches have been conducted in the rural communities of South Africa (SA). This has encouraged the development of ICT services such as e-government, e-commerce, e-judiciary, e-health, e-agriculture and many others. Proper ICT implementation has led to societal development, economic empowerment and sustainable communities. However, this is achieved after intensive planning and stakeholders‟ involvement. It is clear that ICTs require energy to function. Most significantly is the fact that a bulk of ICTs in low resource communities (LRC) are mainly donations and less consideration if any is made on their energy consumption. LRC are regions with minimum access to energy, clean water, educational facilities, health facilities, government facilities, technology etc. There have been debates on whether in LRC ICTs are consuming energy. Most ICTs have been deployed without much consideration on the required energy consumption. On the other hand, less research has been done on the sustainability of ICTs, especially considering that all ICT devices and related platforms rely on the availability of energy. There are a lot of possible low cost energy solutions that are available, which could be used to support ICTs in LRC. However, there are so many ICT services, devices and platforms that are lying idle and not been fully utilized in such areas due to the energy related issues. In most cases, ICT solutions in LRC are introduced mainly with Computer Science and Information Systems researchers, without including other key stakeholders like energy experts. The research presents a Cost Effecient Energy Management Model that could be used to assist ICT for Development (ICT4D) platforms or projects in LRC. Both qualitative and quantitative research methods were used within the Siyakhula Living Lab (SLL) in Eastern Cape (EC) Province of SA. Design Science theory is considered for the designing of the model. The SLL is an ICT project which is undertaken within the Dwesa, Bulembu and Alice rural communities. In this dissertation, Dwesa rural community is the chosen case. The surrounding schools in the communities have been used as the ICT point of contact. Interviews, questionnaires, literature v review, action research, focus group, experiments, formulas and evaluation were the specific methods used to conduct this research. Results show that ICTs deployed in the SLLs are mainly donations which consume much energy. The main source of energy use within the SLLs is electricity. From the three schools that were selected where ICTs have been deployed it was found that the electricity bill has increased enormously. This has caused some schools not to open the computer laboratories, which are supposed to be used by the community members. It was also found that there is no energy management plan or solution in place for the SLL resources. The findings show that ICTs within the SLL are been affected by energy related subjects, though the community has been willing to pay for electricity. The Cost Efficient Energy Management Model is proposed at the end of the dissertation. The model is targeted for ICT service providers and has five (5) main pillars i.e stakeholders‟ engagement, energy and ICT infrastructure, new business models, monitoring and evaluation, and finally awareness and training. The dissertation identified all the ICT resources and services at three selected schools within the SLL and drew up the energy consumption for each school. All schools indicated that there has been an increase in the electricity bill after the introduction of the SLL project. There was a clear indication that no energy expert was involved in the establishment of the SLLs. The dissertation indicates that there is a need for renewable source of energy for ICTs to improve service delivery in LRC. ICT service providers should consider energy subjects when planning for development of such solutions in LRC. This research focuses on designing a low cost ICT energy model to inform on ICTs energy consumption in LRC. It further outlines the possible ICT energy solutions that could be used to benefit targeted communities.
- Full Text:
- Date Issued: 2018
- Authors: Mbotoloshi, Dumisani
- Date: 2018
- Subjects: Information technology Communication in community development|
- Language: English
- Type: Thesis , Masters , MSc (Computer Science )
- Identifier: http://hdl.handle.net/10353/14538 , vital:39999
- Description: A couple of Information and Communication Technology (ICT) researches have been conducted in the rural communities of South Africa (SA). This has encouraged the development of ICT services such as e-government, e-commerce, e-judiciary, e-health, e-agriculture and many others. Proper ICT implementation has led to societal development, economic empowerment and sustainable communities. However, this is achieved after intensive planning and stakeholders‟ involvement. It is clear that ICTs require energy to function. Most significantly is the fact that a bulk of ICTs in low resource communities (LRC) are mainly donations and less consideration if any is made on their energy consumption. LRC are regions with minimum access to energy, clean water, educational facilities, health facilities, government facilities, technology etc. There have been debates on whether in LRC ICTs are consuming energy. Most ICTs have been deployed without much consideration on the required energy consumption. On the other hand, less research has been done on the sustainability of ICTs, especially considering that all ICT devices and related platforms rely on the availability of energy. There are a lot of possible low cost energy solutions that are available, which could be used to support ICTs in LRC. However, there are so many ICT services, devices and platforms that are lying idle and not been fully utilized in such areas due to the energy related issues. In most cases, ICT solutions in LRC are introduced mainly with Computer Science and Information Systems researchers, without including other key stakeholders like energy experts. The research presents a Cost Effecient Energy Management Model that could be used to assist ICT for Development (ICT4D) platforms or projects in LRC. Both qualitative and quantitative research methods were used within the Siyakhula Living Lab (SLL) in Eastern Cape (EC) Province of SA. Design Science theory is considered for the designing of the model. The SLL is an ICT project which is undertaken within the Dwesa, Bulembu and Alice rural communities. In this dissertation, Dwesa rural community is the chosen case. The surrounding schools in the communities have been used as the ICT point of contact. Interviews, questionnaires, literature v review, action research, focus group, experiments, formulas and evaluation were the specific methods used to conduct this research. Results show that ICTs deployed in the SLLs are mainly donations which consume much energy. The main source of energy use within the SLLs is electricity. From the three schools that were selected where ICTs have been deployed it was found that the electricity bill has increased enormously. This has caused some schools not to open the computer laboratories, which are supposed to be used by the community members. It was also found that there is no energy management plan or solution in place for the SLL resources. The findings show that ICTs within the SLL are been affected by energy related subjects, though the community has been willing to pay for electricity. The Cost Efficient Energy Management Model is proposed at the end of the dissertation. The model is targeted for ICT service providers and has five (5) main pillars i.e stakeholders‟ engagement, energy and ICT infrastructure, new business models, monitoring and evaluation, and finally awareness and training. The dissertation identified all the ICT resources and services at three selected schools within the SLL and drew up the energy consumption for each school. All schools indicated that there has been an increase in the electricity bill after the introduction of the SLL project. There was a clear indication that no energy expert was involved in the establishment of the SLLs. The dissertation indicates that there is a need for renewable source of energy for ICTs to improve service delivery in LRC. ICT service providers should consider energy subjects when planning for development of such solutions in LRC. This research focuses on designing a low cost ICT energy model to inform on ICTs energy consumption in LRC. It further outlines the possible ICT energy solutions that could be used to benefit targeted communities.
- Full Text:
- Date Issued: 2018
Molecular characterization of streptococcus agalactiae isolated from pregnant women in the Eastern Cape, South Africa and Windhoek, Namibia and antibacterial activities of some medicinal plant extracts on the isolates
- Authors: Mukesi, Munyaradzi
- Date: 2018
- Subjects: Streptococcus Medicinal plants Pregnant women
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13034 , vital:39437
- Description: Streptococcus agalactiae (S. agalactiae) also known as group B Streptococcus (GBS) is one of the leading causes of bacterial morbidity and mortality among neonates worldwide. It is the cause of invasive Early Onset Disease (EOD), which occurs in the first 7 days of life and characterised by sepsis, pneumonia and meningitis and Late Onset Disease (LOD) occurring between 7 and 89 days of life. Late onset disease is characterised by meningitis and long term neurological sequelae such as cerebral palsy, hearing impairment and cognitive challenges. S. agalactiae does not only infect neonates, it also infects the elderly, immunocompromised individuals and pregnant and non-pregnant women, causing invasive disease. In the world, 10-40 percent of healthy women are rectally or vaginally colonised with GBS and they face the risk of passing it to their babies during the process of childbirth. During parturition, a GBS colonized pregnant woman transfers the bacterium to her new-born as the baby passes through the ruptured membrane, thus infecting the child. However, GBS has been reported to be transferred even without rupture of membranes. Once it infects the membranes, it is transferred into the amniotic fluid and subsequently infects the baby. It can be aspirated into the lungs causing pneumonia or it can infect the blood stream and disseminated round the body causing septicaemia, meningitis and other infections. Once in the neonate’s body, the bacteria is able to evade the immune system as the host immune system is not yet fully developed. Bacterial evasion of the immune system is enhanced by its various virulence factors which are deployed to help it escape the immune system. These include the polysaccharide capsule, haemolysin and the release of complement inactivating factors such C5a peptidase. The World Health Organisation (WHO) (2010) recommends universal screening of pregnant women to identify those colonised and who are at risk of passing the bacterium to their babies during birth. WHO also recommends identification of at risk women and providing Intrapartum Antibiotic Prophylaxis (IAP) using penicillin. However, problems arise in penicillin allergic women and while alternatives for IAP include erythromycin and clindamycin, there is increasing resistance to these drugs thereby limiting therapeutic options. Antimicrobial susceptibility testing is also not always possible in most resource constrained countries due to poor infrastructure, limited access to health care and the logistical problems in implementing the WHO guidelines. Alternative therapeutic options to GBS infection include developing new and potent antibiotics, development of a vaccine, use of medicinal plants and the use of bacteriophage therapy. While these look like better alternatives there is massive scientific work to be carried out to ensure proper characterisation and efficiency of such alternatives. This process should be followed by in vitro diagnostic testing, experiments with animal models and clinical trials. The problems encountered during vaccine development to curtail GBS infection are compounded by the multiplicity of S. agalactiae capsular types which vary in different geographic locations. Medicinal plants are a cheap and convenient option since they are widely used in communities but the phytochemical components of the plants have to be identified and subjected to in vitro testing to evaluate their therapeutic efficacy as antimicrobial agents. This study therefore sought to isolate GBS from pregnant women between 35 and 37 weeks gestation in Windhoek (Namibia) and the Eastern Cape (South Africa), to determine the prevalence of GBS colonisation in the vagina and rectum of the pregnant women, characterise the isolates by molecular techniques, determine the antimicrobial resistance profiles and genes of the isolates and explore the efficacies of medicinal plant extracts as possible candidates for therapeutic options.
- Full Text:
- Date Issued: 2018
- Authors: Mukesi, Munyaradzi
- Date: 2018
- Subjects: Streptococcus Medicinal plants Pregnant women
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13034 , vital:39437
- Description: Streptococcus agalactiae (S. agalactiae) also known as group B Streptococcus (GBS) is one of the leading causes of bacterial morbidity and mortality among neonates worldwide. It is the cause of invasive Early Onset Disease (EOD), which occurs in the first 7 days of life and characterised by sepsis, pneumonia and meningitis and Late Onset Disease (LOD) occurring between 7 and 89 days of life. Late onset disease is characterised by meningitis and long term neurological sequelae such as cerebral palsy, hearing impairment and cognitive challenges. S. agalactiae does not only infect neonates, it also infects the elderly, immunocompromised individuals and pregnant and non-pregnant women, causing invasive disease. In the world, 10-40 percent of healthy women are rectally or vaginally colonised with GBS and they face the risk of passing it to their babies during the process of childbirth. During parturition, a GBS colonized pregnant woman transfers the bacterium to her new-born as the baby passes through the ruptured membrane, thus infecting the child. However, GBS has been reported to be transferred even without rupture of membranes. Once it infects the membranes, it is transferred into the amniotic fluid and subsequently infects the baby. It can be aspirated into the lungs causing pneumonia or it can infect the blood stream and disseminated round the body causing septicaemia, meningitis and other infections. Once in the neonate’s body, the bacteria is able to evade the immune system as the host immune system is not yet fully developed. Bacterial evasion of the immune system is enhanced by its various virulence factors which are deployed to help it escape the immune system. These include the polysaccharide capsule, haemolysin and the release of complement inactivating factors such C5a peptidase. The World Health Organisation (WHO) (2010) recommends universal screening of pregnant women to identify those colonised and who are at risk of passing the bacterium to their babies during birth. WHO also recommends identification of at risk women and providing Intrapartum Antibiotic Prophylaxis (IAP) using penicillin. However, problems arise in penicillin allergic women and while alternatives for IAP include erythromycin and clindamycin, there is increasing resistance to these drugs thereby limiting therapeutic options. Antimicrobial susceptibility testing is also not always possible in most resource constrained countries due to poor infrastructure, limited access to health care and the logistical problems in implementing the WHO guidelines. Alternative therapeutic options to GBS infection include developing new and potent antibiotics, development of a vaccine, use of medicinal plants and the use of bacteriophage therapy. While these look like better alternatives there is massive scientific work to be carried out to ensure proper characterisation and efficiency of such alternatives. This process should be followed by in vitro diagnostic testing, experiments with animal models and clinical trials. The problems encountered during vaccine development to curtail GBS infection are compounded by the multiplicity of S. agalactiae capsular types which vary in different geographic locations. Medicinal plants are a cheap and convenient option since they are widely used in communities but the phytochemical components of the plants have to be identified and subjected to in vitro testing to evaluate their therapeutic efficacy as antimicrobial agents. This study therefore sought to isolate GBS from pregnant women between 35 and 37 weeks gestation in Windhoek (Namibia) and the Eastern Cape (South Africa), to determine the prevalence of GBS colonisation in the vagina and rectum of the pregnant women, characterise the isolates by molecular techniques, determine the antimicrobial resistance profiles and genes of the isolates and explore the efficacies of medicinal plant extracts as possible candidates for therapeutic options.
- Full Text:
- Date Issued: 2018
Correlations between the occurence of virulent helicobacter pylori strains and chronic disease conditions in dyspeptic patients hospitalized in Chris Hani Baragwanath Hospital, Gauteng Province, South Africa
- Authors: Mzukwa, Asisipho
- Date: 2018
- Subjects: Helicobacter pylori infections Helicobacter pylori Bacterial diseases
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/10885 , vital:35905
- Description: Introduction: Individuals predisposed to different chronic disease conditions such as type 2 diabetes mellitus (T2DM), hypertension (HPT) and human immunodeficiency virus (HIV) might be susceptible to persistent H. pylori colonization, which overtime encourages infection with virulent strains. The presence of different types of H. pylori virulence factors especially cagA, dupA and various combinations of vacA subtypes (s1/m1, s2/m1 and s2m2) confer a higher risk of gastric disease development. Aim: This study seeks to recover H. pylori from gastric biopsy specimen from patients with different chronic disease conditions referred to the GIT unit at Chris Hani Baragwanath Academic Hospital, Soweto, and confirm them and further determine the presence of virulent H. pylori strains in patients with T2DM, HPT and HIV. Methods: Gastric biopsies were obtained from 101 patients with different chronic disease conditions after obtaining consent between August 2017 and February 2018. H. pylori was isolated on selective Colombia blood agar. Presumptive isolates were identified following standard microbiology and biochemical technique. These isolates were confirmed by polymerase chain reaction (PCR) targeting the glmM gene. The H. pylori positive samples were further screened for cagA, dupA and vacA genotypes. Results: H. pylori was recovered from 26 patients, of which 8 were patients with T2DM, 10 with HPT and 8 with HIV. There was no correlation between H. pylori infection and the chronic conditions, but the majority of H. pylori positive participant carried virulent H. pylori strains. The cagA and the dupA genes were more prevalent in T2DM and HPT patients, however the association between these genes and the 2 chronic conditions was not significant. The vacA subtypes common in hypertensive patients compared to the other conditions were the s1m1, s1m2, and s2m2 and the association between these vacA forms and hypertension was significant. Majority of HIV infected patients were found to carry non-virulent H. pylori strains. Conclusion: The prevalence of H. pylori among the general population of patients with T2DM, HPT and HIV was low. Although infected patients are found to be carrying virulent strains of H. pylori, there is no significant association established between the virulent strains and the chronic conditions. Furthermore, HIV-infected patients were found to be carrying non-virulent strains of H. pylori.
- Full Text:
- Date Issued: 2018
- Authors: Mzukwa, Asisipho
- Date: 2018
- Subjects: Helicobacter pylori infections Helicobacter pylori Bacterial diseases
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/10885 , vital:35905
- Description: Introduction: Individuals predisposed to different chronic disease conditions such as type 2 diabetes mellitus (T2DM), hypertension (HPT) and human immunodeficiency virus (HIV) might be susceptible to persistent H. pylori colonization, which overtime encourages infection with virulent strains. The presence of different types of H. pylori virulence factors especially cagA, dupA and various combinations of vacA subtypes (s1/m1, s2/m1 and s2m2) confer a higher risk of gastric disease development. Aim: This study seeks to recover H. pylori from gastric biopsy specimen from patients with different chronic disease conditions referred to the GIT unit at Chris Hani Baragwanath Academic Hospital, Soweto, and confirm them and further determine the presence of virulent H. pylori strains in patients with T2DM, HPT and HIV. Methods: Gastric biopsies were obtained from 101 patients with different chronic disease conditions after obtaining consent between August 2017 and February 2018. H. pylori was isolated on selective Colombia blood agar. Presumptive isolates were identified following standard microbiology and biochemical technique. These isolates were confirmed by polymerase chain reaction (PCR) targeting the glmM gene. The H. pylori positive samples were further screened for cagA, dupA and vacA genotypes. Results: H. pylori was recovered from 26 patients, of which 8 were patients with T2DM, 10 with HPT and 8 with HIV. There was no correlation between H. pylori infection and the chronic conditions, but the majority of H. pylori positive participant carried virulent H. pylori strains. The cagA and the dupA genes were more prevalent in T2DM and HPT patients, however the association between these genes and the 2 chronic conditions was not significant. The vacA subtypes common in hypertensive patients compared to the other conditions were the s1m1, s1m2, and s2m2 and the association between these vacA forms and hypertension was significant. Majority of HIV infected patients were found to carry non-virulent H. pylori strains. Conclusion: The prevalence of H. pylori among the general population of patients with T2DM, HPT and HIV was low. Although infected patients are found to be carrying virulent strains of H. pylori, there is no significant association established between the virulent strains and the chronic conditions. Furthermore, HIV-infected patients were found to be carrying non-virulent strains of H. pylori.
- Full Text:
- Date Issued: 2018