The taxonomy of the topminnows (Teleostei: Cyprinodontiformes) (Procatopodidae: Procatopodinae) of southern Africa
- Authors: Van Zeeventer, Ryan Matthew
- Date: 2020
- Subjects: Cyprinodontiformes -- Africa, Southern , Killifishes -- Africa, Southern
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/145559 , vital:38449
- Description: Taxonomy is a tool that plays a crucial role in the implementation of effective management assessments, the ability to identify different fish species and their life stages, and create effective conservation strategies. Recent years have seen an increase in the discovery of cryptic species which could have an effect on how we implement conservation strategies, increasing the importance of accurate taxonomic assessments. The southern African topminnows of the genera Micropanchax and Lacustricola (Family Procatopodidae) include several species of egg-laying fishes that live in the marginal areas of rivers and lakes throughout the river systems of southern Africa in separated and connected populations. It was recently discovered that these populations showed subtle differences in their morphology and colouration, which led to the belief that new and cryptic species may be present. Previous studies of the Procatopodidae relied heavily on phylogenetic analyses that drew on morphological traits without reliance on molecular methods of analysis. A few of the taxonomic issues were resolved through these limited studies but ultimately the taxonomic status of the Procatopodidae remained poorly understood. Furthermore, these studies had not been updated in recent years and hence the benefits of new technology had not been brought to bear on the issues. A multi-gene analysis using standard phylogenetic methods and five molecular markers (mitochondrial cytochrome C oxidase (COI), mitochondrial cytochrome b (cytb), mitochondrial 16S ribosomal RNA (16S rRNA), nuclear 28S ribosomal RNA (28S rRNA) and mitochondrial Tyrosine Kinase (X-src) (TyrK)) allowed phylogenetic trees to be made which demonstrated clear relationships within Micropanchax and Lacustricola of southern Africa and the out-groups used in the analysis. The inference trees showed that Micropanchax johnstoni was represented by three clades and was shown to be polyphyletic while Micropanchax hutereaui, which was represented by two clades, and Micropanchax katangae, which was represented by one clade, were monophyletic. The two species of Lacustricola, L. myaposae and L. macrurus showed very close relationships to Micropanchax and it is suggested that these two species be transferred to Micropanchax, leaving Lacustricola to only be found in central Africa.
- Full Text:
- Date Issued: 2020
- Authors: Van Zeeventer, Ryan Matthew
- Date: 2020
- Subjects: Cyprinodontiformes -- Africa, Southern , Killifishes -- Africa, Southern
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/145559 , vital:38449
- Description: Taxonomy is a tool that plays a crucial role in the implementation of effective management assessments, the ability to identify different fish species and their life stages, and create effective conservation strategies. Recent years have seen an increase in the discovery of cryptic species which could have an effect on how we implement conservation strategies, increasing the importance of accurate taxonomic assessments. The southern African topminnows of the genera Micropanchax and Lacustricola (Family Procatopodidae) include several species of egg-laying fishes that live in the marginal areas of rivers and lakes throughout the river systems of southern Africa in separated and connected populations. It was recently discovered that these populations showed subtle differences in their morphology and colouration, which led to the belief that new and cryptic species may be present. Previous studies of the Procatopodidae relied heavily on phylogenetic analyses that drew on morphological traits without reliance on molecular methods of analysis. A few of the taxonomic issues were resolved through these limited studies but ultimately the taxonomic status of the Procatopodidae remained poorly understood. Furthermore, these studies had not been updated in recent years and hence the benefits of new technology had not been brought to bear on the issues. A multi-gene analysis using standard phylogenetic methods and five molecular markers (mitochondrial cytochrome C oxidase (COI), mitochondrial cytochrome b (cytb), mitochondrial 16S ribosomal RNA (16S rRNA), nuclear 28S ribosomal RNA (28S rRNA) and mitochondrial Tyrosine Kinase (X-src) (TyrK)) allowed phylogenetic trees to be made which demonstrated clear relationships within Micropanchax and Lacustricola of southern Africa and the out-groups used in the analysis. The inference trees showed that Micropanchax johnstoni was represented by three clades and was shown to be polyphyletic while Micropanchax hutereaui, which was represented by two clades, and Micropanchax katangae, which was represented by one clade, were monophyletic. The two species of Lacustricola, L. myaposae and L. macrurus showed very close relationships to Micropanchax and it is suggested that these two species be transferred to Micropanchax, leaving Lacustricola to only be found in central Africa.
- Full Text:
- Date Issued: 2020
A correlational analysis investigating relationships between gender role ideology and attitudes towards gender-based violence
- Authors: Krutani, Siposetu
- Date: 2019
- Subjects: Women -- Violence against -- South Africa , Sex role -- Psychological aspects -- South Africa , Male domination (Social structure) -- South Africa , Rhodes University -- Students -- Attitudes , Rape in universities and colleges -- South Africa , Social movements -- South Africa -- Makhanda , Women college students -- Violence against -- South Africa , Male college students -- South Africa -- Attitudes , Women college students -- Psychology -- South Africa , Male college students -- Psychology -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96658 , vital:31305
- Description: This study forms part of a larger project investigating attitudes towards intimate partner violence, dating violence and other forms of gender-based violence with the Rhodes University context. The primary purpose was to establish a baseline descriptive understanding of participants‟ attitudes towards and perceptions of gender-based violence. With the aim to generate results that would somehow inform the larger project, the current study sought to investigate whether a relationship exists between gender-role ideology and attitudes towards gender-based violence amongst a university population which was inclusive of registered students and employees of the university (n = 308). Four samples were categorised: student sample, academic staff sample, administrative support staff sample and operational support staff sample. A once-off, cross sectional survey design was used to obtain the data. The results of the study revealed that the participants in the study uphold largely non-traditional gender-role ideologies, are generally intolerant of dating violence and are rejecting of rape myths. As predicted in the literature, the study revealed that demographics such as gender, religion, age, level of education, number of years spent in the institution, race, and student accommodation have an impact on the relationship between adherence to traditional gender-role ideology and tolerance towards dating violence, as well as on the relationship between adherence to traditional gender-role ideology and rape myth acceptance and the relationship between rape myth acceptance and tolerance towards dating violence. The study contributes to the growing body of knowledge on gender-based violence in institutions of higher learning and could help improve sexual violence prevention programmes in such contexts.
- Full Text:
- Date Issued: 2019
- Authors: Krutani, Siposetu
- Date: 2019
- Subjects: Women -- Violence against -- South Africa , Sex role -- Psychological aspects -- South Africa , Male domination (Social structure) -- South Africa , Rhodes University -- Students -- Attitudes , Rape in universities and colleges -- South Africa , Social movements -- South Africa -- Makhanda , Women college students -- Violence against -- South Africa , Male college students -- South Africa -- Attitudes , Women college students -- Psychology -- South Africa , Male college students -- Psychology -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96658 , vital:31305
- Description: This study forms part of a larger project investigating attitudes towards intimate partner violence, dating violence and other forms of gender-based violence with the Rhodes University context. The primary purpose was to establish a baseline descriptive understanding of participants‟ attitudes towards and perceptions of gender-based violence. With the aim to generate results that would somehow inform the larger project, the current study sought to investigate whether a relationship exists between gender-role ideology and attitudes towards gender-based violence amongst a university population which was inclusive of registered students and employees of the university (n = 308). Four samples were categorised: student sample, academic staff sample, administrative support staff sample and operational support staff sample. A once-off, cross sectional survey design was used to obtain the data. The results of the study revealed that the participants in the study uphold largely non-traditional gender-role ideologies, are generally intolerant of dating violence and are rejecting of rape myths. As predicted in the literature, the study revealed that demographics such as gender, religion, age, level of education, number of years spent in the institution, race, and student accommodation have an impact on the relationship between adherence to traditional gender-role ideology and tolerance towards dating violence, as well as on the relationship between adherence to traditional gender-role ideology and rape myth acceptance and the relationship between rape myth acceptance and tolerance towards dating violence. The study contributes to the growing body of knowledge on gender-based violence in institutions of higher learning and could help improve sexual violence prevention programmes in such contexts.
- Full Text:
- Date Issued: 2019
The time course changes in selected fatigue indicators in moderately trained participants
- Authors: Maduna, Bongani Cyprian
- Date: 2019
- Subjects: Athletes -- Health and hygiene , Fatigue , Athletes -- Physiology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76354 , vital:30553
- Description: Background: During daily physical activities, individuals will encounter some level of fatigue. This is especially true for athletes who exert their bodies to achieve superior performance and attempt to delay the onset of fatigue as far as possible. However, fatigue is a progressive process that is part of physical exercise. It is therefore, important to understand the various factors associated with fatigue. Objective: The purpose of this research project was to observe the changes in perceptual, physiological responses, and workload while participants performed a fatiguing cycling exercise task. In order to observe the aforementioned changes, one of the three variables, either perceptual, physiological responses or workload was kept constant, while the other two were observed as dependent variables. There were three test conditions, which permitted each variable to be kept constant in at least one of the three test conditions. Methods: Thirty-six apparently healthy university students were recruited for the study. The exercise was of 35 minute duration for each condition, with the data collection for HR (physiological response), RPE (perceptual response), and power output (workload) occurring at two minute intervals from the eighth minute until the thirtieth minute. The participants were required to perform a peak-power-output test in order set the relative performance ranges for each participant in order to elicit an observable fatigue response from all the participants. The three conditions included constant HR response, constant workload, and constant RPE response where each participant performed all of the above conditions on separate days.Results: The perceptual (RPE) response increased significantly (p<0.05) over time in all three test conditions, even under the constant RPE condition where it was expected to remain unchanged throughout the test duration. The HR response only demonstrated a significant (p<0.05) increase over time under the constant workload condition. Lastly, workload remained constant in all three testing conditions. Conclusion: Participants may be able to exercise for longer periods during sub-maximal exercise if they disregard the RPE warning response. In the current study, the RPE response illustrated that participants were being exerted more over time; however, the participants still had physiological and workload capacity to continue exercising. This research project has confirmed the fact that fatigue is a multifaceted phenomenon. Furthermore, it has been illustrated that RPE response alone as an indicator of fatigue onset may be misleading as participants did not breach the HR and workload steady state during the current research. Therefore, it may be more appropriate to assess fatigue onset through the assessment of more than one fatigue variable in order to ensure increased accuracy of the participants’ fatigue state assessment.
- Full Text:
- Date Issued: 2019
- Authors: Maduna, Bongani Cyprian
- Date: 2019
- Subjects: Athletes -- Health and hygiene , Fatigue , Athletes -- Physiology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76354 , vital:30553
- Description: Background: During daily physical activities, individuals will encounter some level of fatigue. This is especially true for athletes who exert their bodies to achieve superior performance and attempt to delay the onset of fatigue as far as possible. However, fatigue is a progressive process that is part of physical exercise. It is therefore, important to understand the various factors associated with fatigue. Objective: The purpose of this research project was to observe the changes in perceptual, physiological responses, and workload while participants performed a fatiguing cycling exercise task. In order to observe the aforementioned changes, one of the three variables, either perceptual, physiological responses or workload was kept constant, while the other two were observed as dependent variables. There were three test conditions, which permitted each variable to be kept constant in at least one of the three test conditions. Methods: Thirty-six apparently healthy university students were recruited for the study. The exercise was of 35 minute duration for each condition, with the data collection for HR (physiological response), RPE (perceptual response), and power output (workload) occurring at two minute intervals from the eighth minute until the thirtieth minute. The participants were required to perform a peak-power-output test in order set the relative performance ranges for each participant in order to elicit an observable fatigue response from all the participants. The three conditions included constant HR response, constant workload, and constant RPE response where each participant performed all of the above conditions on separate days.Results: The perceptual (RPE) response increased significantly (p<0.05) over time in all three test conditions, even under the constant RPE condition where it was expected to remain unchanged throughout the test duration. The HR response only demonstrated a significant (p<0.05) increase over time under the constant workload condition. Lastly, workload remained constant in all three testing conditions. Conclusion: Participants may be able to exercise for longer periods during sub-maximal exercise if they disregard the RPE warning response. In the current study, the RPE response illustrated that participants were being exerted more over time; however, the participants still had physiological and workload capacity to continue exercising. This research project has confirmed the fact that fatigue is a multifaceted phenomenon. Furthermore, it has been illustrated that RPE response alone as an indicator of fatigue onset may be misleading as participants did not breach the HR and workload steady state during the current research. Therefore, it may be more appropriate to assess fatigue onset through the assessment of more than one fatigue variable in order to ensure increased accuracy of the participants’ fatigue state assessment.
- Full Text:
- Date Issued: 2019
In silico study of Plasmodium 1-deoxy-dxylulose 5-phosphate reductoisomerase (DXR) for identification of novel inhibitors from SANCDB
- Authors: Diallo, Bakary N'tji
- Date: 2018
- Subjects: Plasmodium 1-deoxy-dxylulose 5-phosphate reductoisomerase , Isoprenoids , Plasmodium , Antimalarials , Malaria -- Chemotherapy , Molecules -- Models , Molecular dynamics , South African Natural Compounds Database
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64012 , vital:28523
- Description: Malaria remains a major health concern with a complex parasite constantly developing resistance to the different drugs introduced to treat it, threatening the efficacy of the current ACT treatment recommended by WHO (World Health Organization). Different antimalarial compounds with different mechanisms of action are ideal as this decreases chances of resistance occurring. Inhibiting DXR and consequently the MEP pathway is a good strategy to find a new antimalarial with a novel mode of action. From literature, all the enzymes of the MEP pathway have also been shown to be indispensable for the synthesis of isoprenoids. They have been validated as drug targets and the X-ray structure of each of the enzymes has been solved. DXR is a protein which catalyses the second step of the MEP pathway. There are currently 255 DXR inhibitors in the Binding Database (accessed November 2017) generally based on the fosmidomycin structural scaffold and thus often showing poor drug likeness properties. This study aims to research new DXR inhibitors using in silico techniques. We analysed the protein sequence and built 3D models in close and open conformations for the different Plasmodium sequences. Then SANCDB compounds were screened to identify new potential DXR inhibitors with new chemical scaffolds. Finally, the identified hits were submitted to molecular dynamics studies, preceded by a parameterization of the manganese atom in the protein active site.
- Full Text:
- Date Issued: 2018
- Authors: Diallo, Bakary N'tji
- Date: 2018
- Subjects: Plasmodium 1-deoxy-dxylulose 5-phosphate reductoisomerase , Isoprenoids , Plasmodium , Antimalarials , Malaria -- Chemotherapy , Molecules -- Models , Molecular dynamics , South African Natural Compounds Database
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64012 , vital:28523
- Description: Malaria remains a major health concern with a complex parasite constantly developing resistance to the different drugs introduced to treat it, threatening the efficacy of the current ACT treatment recommended by WHO (World Health Organization). Different antimalarial compounds with different mechanisms of action are ideal as this decreases chances of resistance occurring. Inhibiting DXR and consequently the MEP pathway is a good strategy to find a new antimalarial with a novel mode of action. From literature, all the enzymes of the MEP pathway have also been shown to be indispensable for the synthesis of isoprenoids. They have been validated as drug targets and the X-ray structure of each of the enzymes has been solved. DXR is a protein which catalyses the second step of the MEP pathway. There are currently 255 DXR inhibitors in the Binding Database (accessed November 2017) generally based on the fosmidomycin structural scaffold and thus often showing poor drug likeness properties. This study aims to research new DXR inhibitors using in silico techniques. We analysed the protein sequence and built 3D models in close and open conformations for the different Plasmodium sequences. Then SANCDB compounds were screened to identify new potential DXR inhibitors with new chemical scaffolds. Finally, the identified hits were submitted to molecular dynamics studies, preceded by a parameterization of the manganese atom in the protein active site.
- Full Text:
- Date Issued: 2018
Acacia Mearnsii debarking: comparing different debarking technologies in the KwaZulu-Natal and Mpumalanga forestry regions of South Africa
- Authors: Eggers, John Rolf
- Date: 2010
- Subjects: Acacia mearnsii -- South Africa -- KwaZulu-Natal , Acacia mearnsii -- South Africa -- Mpumalanga , Wattles (Plants) -- South Africa -- KwaZulu-Natal , Wattles (Plants) -- South Africa -- Mpumalanga
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10740 , http://hdl.handle.net/10948/1456 , Acacia mearnsii -- South Africa -- KwaZulu-Natal , Acacia mearnsii -- South Africa -- Mpumalanga , Wattles (Plants) -- South Africa -- KwaZulu-Natal , Wattles (Plants) -- South Africa -- Mpumalanga
- Description: Debarking of Acacia mearnsii in South Africa has been conducted using mainly manual systems. Labour shortages and reliability of these systems has caused interest in alternative systems that might be able to debark A. mearnsii. The aim of the research is to compare three mechanised debarking technologies used to debark A. mearnsii. Research trials were conducted on the Demuth, Hyena and Hypro debarkers that would form part of semi-mechanised harvesting systems. The debarking technologies were analysed and compared in terms of productivity per productive machine hour (PMH), debarking quality, system costs and the quality of the bark that was produced. Furthermore, the effect that tree volume, strippability and form have on each of the debarking technologies was determined. The debarking technologies were affected by each of the factors researched. Decreasing tree form had a negative effect on the productivity of each of the technologies. An increase in strippability class (strengthening wood-bark bond strength) caused a decrease in the productivity of each of the machines. An increasing tree volume had a positive effect on the productivity for the three debarking technologies. After the debarking had taken place, samples of bark were analysed at a laboratory to determine if it was acceptable for the processing facilities. Each of the debarking technologies produced bark of varying dimensions, but they were all found to be acceptable. The system costs of the three debarking technologies were compared to a manual system cost at tree volumes of 0.1m³, 0.15m³ and 0.2m³. The Demuth debarker had the best system cost for a tree size of 0.1m³, while the manual system was best for tree volumes 0.15m³ and 0.2m³. The Demuth, Hyena and manual system costs were very similar for each of the tree volumes, with the Hypro being a little higher.
- Full Text:
- Date Issued: 2010
- Authors: Eggers, John Rolf
- Date: 2010
- Subjects: Acacia mearnsii -- South Africa -- KwaZulu-Natal , Acacia mearnsii -- South Africa -- Mpumalanga , Wattles (Plants) -- South Africa -- KwaZulu-Natal , Wattles (Plants) -- South Africa -- Mpumalanga
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10740 , http://hdl.handle.net/10948/1456 , Acacia mearnsii -- South Africa -- KwaZulu-Natal , Acacia mearnsii -- South Africa -- Mpumalanga , Wattles (Plants) -- South Africa -- KwaZulu-Natal , Wattles (Plants) -- South Africa -- Mpumalanga
- Description: Debarking of Acacia mearnsii in South Africa has been conducted using mainly manual systems. Labour shortages and reliability of these systems has caused interest in alternative systems that might be able to debark A. mearnsii. The aim of the research is to compare three mechanised debarking technologies used to debark A. mearnsii. Research trials were conducted on the Demuth, Hyena and Hypro debarkers that would form part of semi-mechanised harvesting systems. The debarking technologies were analysed and compared in terms of productivity per productive machine hour (PMH), debarking quality, system costs and the quality of the bark that was produced. Furthermore, the effect that tree volume, strippability and form have on each of the debarking technologies was determined. The debarking technologies were affected by each of the factors researched. Decreasing tree form had a negative effect on the productivity of each of the technologies. An increase in strippability class (strengthening wood-bark bond strength) caused a decrease in the productivity of each of the machines. An increasing tree volume had a positive effect on the productivity for the three debarking technologies. After the debarking had taken place, samples of bark were analysed at a laboratory to determine if it was acceptable for the processing facilities. Each of the debarking technologies produced bark of varying dimensions, but they were all found to be acceptable. The system costs of the three debarking technologies were compared to a manual system cost at tree volumes of 0.1m³, 0.15m³ and 0.2m³. The Demuth debarker had the best system cost for a tree size of 0.1m³, while the manual system was best for tree volumes 0.15m³ and 0.2m³. The Demuth, Hyena and manual system costs were very similar for each of the tree volumes, with the Hypro being a little higher.
- Full Text:
- Date Issued: 2010
An investigation of the role of news values in the selection of news sources in a contemporary third world newspaper: a case study of the Daily Nation newspaper
- Authors: Kisuke, Connie Syomiti
- Date: 2005
- Subjects: Daily Nation (Nairobi, Kenya) , Government and the press -- Africa , Reporters and reporting , Mass media -- Political aspects -- Africa , Newspapers -- Africa , Journalism -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3446 , http://hdl.handle.net/10962/d1002900 , Daily Nation (Nairobi, Kenya) , Government and the press -- Africa , Reporters and reporting , Mass media -- Political aspects -- Africa , Newspapers -- Africa , Journalism -- Social aspects
- Description: News in our contemporary newspapers has come to be associated more and more with what the elites do and say. Both their deeds and misdeeds are treated as newsworthy events and in the process they become newsmakers, both actors and sources of news. Even when they are not directly involved in news events they are sought out by journalists to validate those events and to interpret the social reality to the readers as news sources. This study is about the selection of news sources in the Daily Nation, a contemporary, independent newspaper based in Nairobi, Kenya. In this study, I set out to unravel the complex processes that underlie newsmaking and source selection. This study is informed by the theory of news values and the paradigm of the role of media in democracy. Based on qualitative interviews, observations and content analysis of the front-page stories, it investigates the process of news and source selection in front-page stories. Through these approaches, I established that news values are significant criteria that inform journalists in both the selection of front-page news stories and the sources of these stories. I also established that social values of the society in which this newspaper operates are heavily embedded in the news. For example, the journalists preferred male politicians as sources of news in the front-page stories to women, and the elites to ordinary people, and this reflected on the social structures and cultural norms that are prevalent in this society. This study, further, established that the news values of this newspaper share commonly with the Western news media in terms of journalistic conventions and ways of interpreting the social reality in the news. Ideally, the newspaper embraces the principles of democracy in news reporting, but in practice it does not satisfactorily adhere to the full requirements of its democratic role in terms of source selection. The democratic principles in news reporting require, among other things, that the newspaper should allow a diversity of views in the news, representing various groups that are found in real society including the elites, non-elites, women, ordinary people and minorities. In the case of the Daily Nation, a tiny group of elite male professional politicians made up the largest majority of its front-page news sources.
- Full Text:
- Date Issued: 2005
- Authors: Kisuke, Connie Syomiti
- Date: 2005
- Subjects: Daily Nation (Nairobi, Kenya) , Government and the press -- Africa , Reporters and reporting , Mass media -- Political aspects -- Africa , Newspapers -- Africa , Journalism -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3446 , http://hdl.handle.net/10962/d1002900 , Daily Nation (Nairobi, Kenya) , Government and the press -- Africa , Reporters and reporting , Mass media -- Political aspects -- Africa , Newspapers -- Africa , Journalism -- Social aspects
- Description: News in our contemporary newspapers has come to be associated more and more with what the elites do and say. Both their deeds and misdeeds are treated as newsworthy events and in the process they become newsmakers, both actors and sources of news. Even when they are not directly involved in news events they are sought out by journalists to validate those events and to interpret the social reality to the readers as news sources. This study is about the selection of news sources in the Daily Nation, a contemporary, independent newspaper based in Nairobi, Kenya. In this study, I set out to unravel the complex processes that underlie newsmaking and source selection. This study is informed by the theory of news values and the paradigm of the role of media in democracy. Based on qualitative interviews, observations and content analysis of the front-page stories, it investigates the process of news and source selection in front-page stories. Through these approaches, I established that news values are significant criteria that inform journalists in both the selection of front-page news stories and the sources of these stories. I also established that social values of the society in which this newspaper operates are heavily embedded in the news. For example, the journalists preferred male politicians as sources of news in the front-page stories to women, and the elites to ordinary people, and this reflected on the social structures and cultural norms that are prevalent in this society. This study, further, established that the news values of this newspaper share commonly with the Western news media in terms of journalistic conventions and ways of interpreting the social reality in the news. Ideally, the newspaper embraces the principles of democracy in news reporting, but in practice it does not satisfactorily adhere to the full requirements of its democratic role in terms of source selection. The democratic principles in news reporting require, among other things, that the newspaper should allow a diversity of views in the news, representing various groups that are found in real society including the elites, non-elites, women, ordinary people and minorities. In the case of the Daily Nation, a tiny group of elite male professional politicians made up the largest majority of its front-page news sources.
- Full Text:
- Date Issued: 2005
Methods for assessing the susceptibility of freshwater ecosystems in Southern Africa to invasion by alien aquatic animals
- Authors: De Moor, Irene J
- Date: 1994
- Subjects: Biotic communities -- South Africa , Animal introduction , Freshwater ecology -- Africa, Southern , Animal introduction -- South Africa , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5300 , http://hdl.handle.net/10962/d1005145
- Description: Two methods for predicting regions susceptible to invasion by alien aquatic animals were developed for southern Africa (excluding Zimbabwe and Mozambique). In the "traditional" (data-poor) approach, distributions of three categories of alien "indicator" species (warm mesothermal, cold stenothermal and eurytopic) were compared to seven existing biogeographical models of distribution patterns of various animals in southern Africa. On the basis of these comparisons a synthesis model was developed which divided southern Africa into seven regions characterised by their susceptibility to invasion by alien aquatic animals with particular habitat requirements. In the "data-rich," geographic information systems (GIS) approach, the distribution of trout (Oncorhynchus mykiss and Salmo trutta) in selected "sampled regions" was related to elevation (as a surrogate of water temperature) and median annual rainfall (MAR) (as a surrogate of water availability). Using concentration analysis, optimum conditions for trout were identified. Regions within a larger "predictive area" which satisfied these conditions, were plotted as a digital map using the IDRISI package. Using this method seven models of potential trout distribution were generated for the following regions: northern Natal (two); southern Natal/Lesotho/Transkei (three), eastern Cape (two) and western Cape (two). Since two of the models were used to refine the methods, only five models were considered for the final assessment. In a modification of the GIS method, another model of potential trout distribution, based on mean monthly July minimum air temperature and MAR parameters, was developed for the region bounded by 29º - 34º S and 26 º - 32°E. This model showed marked similarities to another model, developed for the region bounded by 29 º - 32°S and 26º - 32°E, which was based on elevation and MAR parameters. The validity of the models developed was assessed by independent experts. Of the six models considered, four received favourable judgements, one was equivocal and one was judged to be poor. Based on these assessments it was concluded that the GIS method has credibility and could be used to develop a "data-rich" model of the susceptibility of southern Africa to invasion by alien aquatic animals. This method represents an alternative to the bioclimatic matching approach developed by scientists in Australia. The GIS method has a number of advantages over the "traditional" method: it is more amenable to testing, has greater flexibility, stores more information, produces images of a finer resolution, and can be easily updated. The traditional method has the advantage of being less expensive and requiring a less extensive database.
- Full Text:
- Date Issued: 1994
- Authors: De Moor, Irene J
- Date: 1994
- Subjects: Biotic communities -- South Africa , Animal introduction , Freshwater ecology -- Africa, Southern , Animal introduction -- South Africa , Geographic information systems
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5300 , http://hdl.handle.net/10962/d1005145
- Description: Two methods for predicting regions susceptible to invasion by alien aquatic animals were developed for southern Africa (excluding Zimbabwe and Mozambique). In the "traditional" (data-poor) approach, distributions of three categories of alien "indicator" species (warm mesothermal, cold stenothermal and eurytopic) were compared to seven existing biogeographical models of distribution patterns of various animals in southern Africa. On the basis of these comparisons a synthesis model was developed which divided southern Africa into seven regions characterised by their susceptibility to invasion by alien aquatic animals with particular habitat requirements. In the "data-rich," geographic information systems (GIS) approach, the distribution of trout (Oncorhynchus mykiss and Salmo trutta) in selected "sampled regions" was related to elevation (as a surrogate of water temperature) and median annual rainfall (MAR) (as a surrogate of water availability). Using concentration analysis, optimum conditions for trout were identified. Regions within a larger "predictive area" which satisfied these conditions, were plotted as a digital map using the IDRISI package. Using this method seven models of potential trout distribution were generated for the following regions: northern Natal (two); southern Natal/Lesotho/Transkei (three), eastern Cape (two) and western Cape (two). Since two of the models were used to refine the methods, only five models were considered for the final assessment. In a modification of the GIS method, another model of potential trout distribution, based on mean monthly July minimum air temperature and MAR parameters, was developed for the region bounded by 29º - 34º S and 26 º - 32°E. This model showed marked similarities to another model, developed for the region bounded by 29 º - 32°S and 26º - 32°E, which was based on elevation and MAR parameters. The validity of the models developed was assessed by independent experts. Of the six models considered, four received favourable judgements, one was equivocal and one was judged to be poor. Based on these assessments it was concluded that the GIS method has credibility and could be used to develop a "data-rich" model of the susceptibility of southern Africa to invasion by alien aquatic animals. This method represents an alternative to the bioclimatic matching approach developed by scientists in Australia. The GIS method has a number of advantages over the "traditional" method: it is more amenable to testing, has greater flexibility, stores more information, produces images of a finer resolution, and can be easily updated. The traditional method has the advantage of being less expensive and requiring a less extensive database.
- Full Text:
- Date Issued: 1994
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