Elucidating Tuta absoluta (Meyrick) invasion and enhancing its management in Eastern Africa : spread, socio-ecological impacts, and potential of a newly imported larval parasitoid for classical biological control Eastern in Africa
- Aigbedion-Atalor, Pascal Osabhahiemen
- Authors: Aigbedion-Atalor, Pascal Osabhahiemen
- Date: 2021
- Subjects: Tuta absoluta -- Biological control , Tomatoes -- Diseases and pests -- Africa, East , Braconidae , Gelechiidae -- Biological control -- Africa, East , Insects as biological pest control agents -- Africa, East
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170421 , vital:41920 , 10.21504/10962/170421
- Description: Agriculture is a fundamental source of sustainable livelihoods in sub-Saharan Africa and millions of people in the region rely solely on small-scale farming for their food security. However, the impacts of invasive alien species (IAS) on crop production are serious, and there is no sign of this abating. Among the recent IAS that have invaded Africa in the last decade, the South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has been one of the most damaging. Following its first record in the Maghreb region of Africa in 2008, T. absoluta rapidly spread throughout Africa with substantial impacts on tomato production, often causing 100% yield loss. Management options adopted against T. absoluta by tomato growers in Africa have been based on the use of synthetic insecticides. While chemical insecticide applications are an important component of an integrated pest management programme, misuse and over-reliance often exacerbates the impacts of T. absolutadue to the development of resistance to commonly used active substances, increasing the fitness of the pest. This thesis sought to understand the socio-economic impacts of the spread of T. absoluta in Eastern Africa and provide effective sustainable pest management strategies to reduce its impacts below economic thresholds. Mapping surveys of Tabsoluta were conducted in 226 tomato agro-ecosystems across four eastern countries (Kenya, Sudan, Tanzania, and Uganda) Eastern Africa from 2016 to 2018 to determine the spatiotemporal distribution of the pest. The impacts of T. absoluta on the livelihoods of tomato growers were also assessed. Here, 200 tomato growers in Kenya were interviewed using a semi-structured questionnaire. Although T. absoluta, a recent invader, was distributed at high infestation levels throughout the subregion (all four countries) and was considered as the most damaging invasive alien species of agriculturally sustainable livelihoods. The arrival of T. absoluta in the subregion has resulted in livelihood losses and increased the cost of tomato production and price of the fruit, and the frequency of pesticide applications. The impact of this pest and the and the absence of effective indigenous natural enemies of the pest in Eastern Africa, was the rationale for the importation of a larval parasitoid, Dolichogenidea gelechiidivoris Marsh Syn.: Apanteles gelechiidivoris Marsh) (Hymenoptera: Braconidae), of T. absoluta from Peru into the quarantine facility of the International Centre of Insect Physiology and ecologyz(icipe), in Kenya. Pre-release assessments on the parasitzation potential of D. gelechiidivoris, encompassing host larval preference and the host suitability, and its reproductive strategy, for classical biological control of T. absoluta in Africa were conducted. Dolichogenidea gelechiidivoris females preferentially oviposited in early (1st and 2nd) larval instars of T. absoluta but parasitized and completed development in all four instars of the host. Host instar did not affect D. gelechiidivoris sex-ratio but females reared on the first instar had significantly fewer eggs than when reared in late larval instars (3rd and 4th). Females of the parasitoid emerged with a high mature egg load which peaked 2 d post-eclosion. The females of D. gelechiidivoris survived 8.51±0.65 d and produced 103±8 offspring per female at 26±4°C (range: 24 to 29°C) and 50–70% relative humidity (RH) in the presence of males and fed honey-water (80% honey). Increasing maternal age decreased the proportion of female offspring. Under the aforementioned laboratory conditions, the Gross and Net reproductive rates were 72 and 39.5 respectively, while the mean generation time was 20 d. The estimated intrinsic rate of natural increase was 0.18. These findings indicate that D. gelechiidivorisis a potential biological control agent of T. absoluta and should be considered for augmentative/inundative release in Kenya and across Africa following host specificity testing and risk assessments. The nature of the interaction between D. gelechidivoris and the predatory mirid bug Nesidiocoris tenuis(Reuter) (Hemiptera: Miridae), an important and widespread natural enemy of T. absoluta in Africa was evaluated because N. tenuis, although being a voracious predator of T. absoluta eggs, it can also prey on the early host larval instars (1st and 2nd) which are the preferred oviposition host stages of D. gelechiidivoris. Here, the impact of N. tenuis feeding on T. absoluta and the effects on D. gelechiidivoris performance was tested. Regardless of the order of introductions (i.e. the sequence of combination with D. gelechiidivoris) and densities (i.e. number of N. tenuis combined with D. gelechiidivoris), there was no intraguild predation by N. tenuis on D. gelechiidivorisas there was little host larval feeding behaviour. Also, the presence of N. tenuis did not affect the oviposition performance of D. gelechiidivoris. Further investigations revealed that the combined efficacy of N. tenuis and D. gelechiidivorison T. absoluta population was significantly higher than either natural enemy alone, thus contributes to the data supporting the release of D. gelechiidivoris in Africa. In concluding, integrating D. gelechiidivoris and N. tenuis in the management of T. absolut could potentially reduce yield losses in tomato in Eastern Africa where the socio-economic impacts of the pest are very serious.
- Full Text:
- Date Issued: 2021
- Authors: Aigbedion-Atalor, Pascal Osabhahiemen
- Date: 2021
- Subjects: Tuta absoluta -- Biological control , Tomatoes -- Diseases and pests -- Africa, East , Braconidae , Gelechiidae -- Biological control -- Africa, East , Insects as biological pest control agents -- Africa, East
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170421 , vital:41920 , 10.21504/10962/170421
- Description: Agriculture is a fundamental source of sustainable livelihoods in sub-Saharan Africa and millions of people in the region rely solely on small-scale farming for their food security. However, the impacts of invasive alien species (IAS) on crop production are serious, and there is no sign of this abating. Among the recent IAS that have invaded Africa in the last decade, the South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has been one of the most damaging. Following its first record in the Maghreb region of Africa in 2008, T. absoluta rapidly spread throughout Africa with substantial impacts on tomato production, often causing 100% yield loss. Management options adopted against T. absoluta by tomato growers in Africa have been based on the use of synthetic insecticides. While chemical insecticide applications are an important component of an integrated pest management programme, misuse and over-reliance often exacerbates the impacts of T. absolutadue to the development of resistance to commonly used active substances, increasing the fitness of the pest. This thesis sought to understand the socio-economic impacts of the spread of T. absoluta in Eastern Africa and provide effective sustainable pest management strategies to reduce its impacts below economic thresholds. Mapping surveys of Tabsoluta were conducted in 226 tomato agro-ecosystems across four eastern countries (Kenya, Sudan, Tanzania, and Uganda) Eastern Africa from 2016 to 2018 to determine the spatiotemporal distribution of the pest. The impacts of T. absoluta on the livelihoods of tomato growers were also assessed. Here, 200 tomato growers in Kenya were interviewed using a semi-structured questionnaire. Although T. absoluta, a recent invader, was distributed at high infestation levels throughout the subregion (all four countries) and was considered as the most damaging invasive alien species of agriculturally sustainable livelihoods. The arrival of T. absoluta in the subregion has resulted in livelihood losses and increased the cost of tomato production and price of the fruit, and the frequency of pesticide applications. The impact of this pest and the and the absence of effective indigenous natural enemies of the pest in Eastern Africa, was the rationale for the importation of a larval parasitoid, Dolichogenidea gelechiidivoris Marsh Syn.: Apanteles gelechiidivoris Marsh) (Hymenoptera: Braconidae), of T. absoluta from Peru into the quarantine facility of the International Centre of Insect Physiology and ecologyz(icipe), in Kenya. Pre-release assessments on the parasitzation potential of D. gelechiidivoris, encompassing host larval preference and the host suitability, and its reproductive strategy, for classical biological control of T. absoluta in Africa were conducted. Dolichogenidea gelechiidivoris females preferentially oviposited in early (1st and 2nd) larval instars of T. absoluta but parasitized and completed development in all four instars of the host. Host instar did not affect D. gelechiidivoris sex-ratio but females reared on the first instar had significantly fewer eggs than when reared in late larval instars (3rd and 4th). Females of the parasitoid emerged with a high mature egg load which peaked 2 d post-eclosion. The females of D. gelechiidivoris survived 8.51±0.65 d and produced 103±8 offspring per female at 26±4°C (range: 24 to 29°C) and 50–70% relative humidity (RH) in the presence of males and fed honey-water (80% honey). Increasing maternal age decreased the proportion of female offspring. Under the aforementioned laboratory conditions, the Gross and Net reproductive rates were 72 and 39.5 respectively, while the mean generation time was 20 d. The estimated intrinsic rate of natural increase was 0.18. These findings indicate that D. gelechiidivorisis a potential biological control agent of T. absoluta and should be considered for augmentative/inundative release in Kenya and across Africa following host specificity testing and risk assessments. The nature of the interaction between D. gelechidivoris and the predatory mirid bug Nesidiocoris tenuis(Reuter) (Hemiptera: Miridae), an important and widespread natural enemy of T. absoluta in Africa was evaluated because N. tenuis, although being a voracious predator of T. absoluta eggs, it can also prey on the early host larval instars (1st and 2nd) which are the preferred oviposition host stages of D. gelechiidivoris. Here, the impact of N. tenuis feeding on T. absoluta and the effects on D. gelechiidivoris performance was tested. Regardless of the order of introductions (i.e. the sequence of combination with D. gelechiidivoris) and densities (i.e. number of N. tenuis combined with D. gelechiidivoris), there was no intraguild predation by N. tenuis on D. gelechiidivorisas there was little host larval feeding behaviour. Also, the presence of N. tenuis did not affect the oviposition performance of D. gelechiidivoris. Further investigations revealed that the combined efficacy of N. tenuis and D. gelechiidivorison T. absoluta population was significantly higher than either natural enemy alone, thus contributes to the data supporting the release of D. gelechiidivoris in Africa. In concluding, integrating D. gelechiidivoris and N. tenuis in the management of T. absolut could potentially reduce yield losses in tomato in Eastern Africa where the socio-economic impacts of the pest are very serious.
- Full Text:
- Date Issued: 2021
Get sleep or get stumped: sleep behaviour in elite South African cricket players during competition
- Authors: McEwan, Kayla
- Date: 2020
- Subjects: Sleep -- Physiological aspects , Cricket players -- Health and hygiene , Cricket players -- South Africa -- Health and hygiene , Cricket -- Health aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/147950 , vital:38696
- Description: Introduction: Good sleep behaviour is associated with achieving optimal athletic performance and reducing the risk of injury. Elite cricket players have unique physical and cognitive demands, and must accommodate for congested competition and travel schedules (all of which increase the risk of disruptive sleep). Further, the political pressures and socioeconomic barriers in South African cricket could affect the sleep of the country’s elite players. Previous research in cricket has focussed on the impact that nutrition, equipment specifications, movement physiology and psychology could elicit on performance (where many professional teams hire support staff to supervise these disciplines); however, there is limited empirical application of sleep research in elite cricket players. Therefore, this study aimed to characterise the sleep behaviours of elite South African cricket players during periods of competition and investigate the relationship between pre-match sleep and cricket performance. Methods: A longitudinal field-based investigation was implemented to monitor the sleep behaviour of 26 elite South African cricket players (age: 28.6 ± 4.0 years; height: 1.8 ± 0.1 m; weight: 85.7 ± 10.8 kg; elite experience: 3.7 ± 4.0 years) during home and away competitive tours. The Morningness-Eveningness Questionnaire and Athlete Sleep Behaviour Questionnaire were administered to identify chronotype and poor sleep behaviours. Players completed an altered version of the Core Consensus Sleep Diary every morning post-travel, pre-match and post-match. Linear mixed model regression was used to compare differences in sleep variables between time-periods, match venues, player roles, match formats, sleep medication and racial groups. Spearman’s correlation (rs) was used to assess the relationship of substance use (alcohol and caffeine), age, elite experience and match performance with selected sleep indices. Statistical significance for all measures was accepted at p < 0.05. Hedge’s (g) were used as the measure of effect size. Results: Light-emitting technology use, effects of travel, late evening alcohol consumption and muscle soreness were the main factors that impacted sleep. Post-match total sleep time (06:31 ± 01:09) was significantly (p < 0.05) shorter compared to post-travel (07:53 ± 01:07; g = 1.19 [0.81;1.57]) and pre-match (08:43 ± 01:03; g = 1.97 [1.55;2.39]) total sleep time. Post-travel sleep onset latency and sleep efficiency were significantly (p < 0.05) shorter (g = 0.74 [0.29;1.29]) and higher (g = 1.35 [0.76;1.94]) at home than away. Although not significant (p > 0.05), allrounders took longer to fall asleep (g = 0.90 [0.23;1.57]), obtained less total sleep (0.76 [0.29;1.42]) and had lower morning freshness scores (g = 1.10 [0.42;1.78]) the night before a match compared to batsmen. Wake after sleep onset and get up time were moderately longer (g = 0.61 [0.22;1.26]) and later (g = 0.62 [0.27;1.17]) before. Twenty20 matches compared to One-Day International matches respectively. Further, sleep duration significantly declined from pre-match to post-match during the multi-day Test format (p = 0.04, g= 0.75 [0.40;1.12]). Late alcohol consumption was significantly (p < 0.05) correlated with a decrease in total sleep time, regardless of match venue (home: rs (49) = -0.69; away: rs (27) = -0.57). During the away condition, an increase in age was significantly associated with longer wake after sleep onset durations (rs (13) = 0.52, p = 0.0003), while greater elite experience was significantly associated with longer total sleep time (rs (72) = 0.36, p = 0.02). The non-sleep medication group took significantly longer to fall asleep compared to the sleep medication group during the first week of the away condition (p = 0.02, g = 0.75 [0.25;1.26]) particularly on nights following transmeridian travel. Although not significant ( p > 0.05), Asian/Indian players had moderately longer sleep onset latencies (g = 1.07 [0.66;1.47]), wake after sleep onset durations (g = 0.86 [0.42;1.29]), and lower subjective sleep quality (g = 0.86 [0.46;1.26]) and morning freshness scores (g = 0.89 [0.47;1.27]) compared to Whites. Similarly, Black Africans had moderately lower subjective sleep quality scores compared to Whites (g = 0.71 [0.43;0.97]). Longer sleep onset latencies and shorter total sleep times were significantly (p < 0.05) associated with poorer One-Day International (rs (28) = -0.57) and Test (rs (12) = 0.59) batting performances respectively. Higher subjective sleep quality scores were significantly associated with better Twenty20 bowling economies (rs (8) = -0.52). Discussion: There was no evidence of poor pre-match sleep behaviour, irrespective of venue; however, the most apparent disruption to sleep occurred post-match (similar to that found in other team-sports). Most disparities in sleep between match venues existed post-travel, with better sleep behaviour observed during the home condition. The differences in sleep patterns found in all three match formats were expected given the variations in format scheduling and duration. Although sleep medication was shown to promote better sleep, its long-term effectiveness was limited. The results promote the implementation of practical strategies aimed to reduce bedtime light-emitting technology use, late evening alcohol consumption and muscle pain. Inter-individual sleep behaviour was found between player roles, age, experience level and race. Moderate associations existed between sleep and markers of batting performance, specifically for the longer, strategic formats of the game. Conclusion: The current study provided new insight of the sleep behaviour in elite South African cricket players during competition. Individualized sleep monitoring practices are encouraged, with specific supervision over older, less experienced players as well as the racial minorities and allrounders of the team. The poor post-match sleep behaviour, together with the sleep and performance correlations, provide ideal opportunities for future interventions to focus on match recovery and the use sleep monitoring as a competitive advantage.
- Full Text:
- Date Issued: 2020
- Authors: McEwan, Kayla
- Date: 2020
- Subjects: Sleep -- Physiological aspects , Cricket players -- Health and hygiene , Cricket players -- South Africa -- Health and hygiene , Cricket -- Health aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/147950 , vital:38696
- Description: Introduction: Good sleep behaviour is associated with achieving optimal athletic performance and reducing the risk of injury. Elite cricket players have unique physical and cognitive demands, and must accommodate for congested competition and travel schedules (all of which increase the risk of disruptive sleep). Further, the political pressures and socioeconomic barriers in South African cricket could affect the sleep of the country’s elite players. Previous research in cricket has focussed on the impact that nutrition, equipment specifications, movement physiology and psychology could elicit on performance (where many professional teams hire support staff to supervise these disciplines); however, there is limited empirical application of sleep research in elite cricket players. Therefore, this study aimed to characterise the sleep behaviours of elite South African cricket players during periods of competition and investigate the relationship between pre-match sleep and cricket performance. Methods: A longitudinal field-based investigation was implemented to monitor the sleep behaviour of 26 elite South African cricket players (age: 28.6 ± 4.0 years; height: 1.8 ± 0.1 m; weight: 85.7 ± 10.8 kg; elite experience: 3.7 ± 4.0 years) during home and away competitive tours. The Morningness-Eveningness Questionnaire and Athlete Sleep Behaviour Questionnaire were administered to identify chronotype and poor sleep behaviours. Players completed an altered version of the Core Consensus Sleep Diary every morning post-travel, pre-match and post-match. Linear mixed model regression was used to compare differences in sleep variables between time-periods, match venues, player roles, match formats, sleep medication and racial groups. Spearman’s correlation (rs) was used to assess the relationship of substance use (alcohol and caffeine), age, elite experience and match performance with selected sleep indices. Statistical significance for all measures was accepted at p < 0.05. Hedge’s (g) were used as the measure of effect size. Results: Light-emitting technology use, effects of travel, late evening alcohol consumption and muscle soreness were the main factors that impacted sleep. Post-match total sleep time (06:31 ± 01:09) was significantly (p < 0.05) shorter compared to post-travel (07:53 ± 01:07; g = 1.19 [0.81;1.57]) and pre-match (08:43 ± 01:03; g = 1.97 [1.55;2.39]) total sleep time. Post-travel sleep onset latency and sleep efficiency were significantly (p < 0.05) shorter (g = 0.74 [0.29;1.29]) and higher (g = 1.35 [0.76;1.94]) at home than away. Although not significant (p > 0.05), allrounders took longer to fall asleep (g = 0.90 [0.23;1.57]), obtained less total sleep (0.76 [0.29;1.42]) and had lower morning freshness scores (g = 1.10 [0.42;1.78]) the night before a match compared to batsmen. Wake after sleep onset and get up time were moderately longer (g = 0.61 [0.22;1.26]) and later (g = 0.62 [0.27;1.17]) before. Twenty20 matches compared to One-Day International matches respectively. Further, sleep duration significantly declined from pre-match to post-match during the multi-day Test format (p = 0.04, g= 0.75 [0.40;1.12]). Late alcohol consumption was significantly (p < 0.05) correlated with a decrease in total sleep time, regardless of match venue (home: rs (49) = -0.69; away: rs (27) = -0.57). During the away condition, an increase in age was significantly associated with longer wake after sleep onset durations (rs (13) = 0.52, p = 0.0003), while greater elite experience was significantly associated with longer total sleep time (rs (72) = 0.36, p = 0.02). The non-sleep medication group took significantly longer to fall asleep compared to the sleep medication group during the first week of the away condition (p = 0.02, g = 0.75 [0.25;1.26]) particularly on nights following transmeridian travel. Although not significant ( p > 0.05), Asian/Indian players had moderately longer sleep onset latencies (g = 1.07 [0.66;1.47]), wake after sleep onset durations (g = 0.86 [0.42;1.29]), and lower subjective sleep quality (g = 0.86 [0.46;1.26]) and morning freshness scores (g = 0.89 [0.47;1.27]) compared to Whites. Similarly, Black Africans had moderately lower subjective sleep quality scores compared to Whites (g = 0.71 [0.43;0.97]). Longer sleep onset latencies and shorter total sleep times were significantly (p < 0.05) associated with poorer One-Day International (rs (28) = -0.57) and Test (rs (12) = 0.59) batting performances respectively. Higher subjective sleep quality scores were significantly associated with better Twenty20 bowling economies (rs (8) = -0.52). Discussion: There was no evidence of poor pre-match sleep behaviour, irrespective of venue; however, the most apparent disruption to sleep occurred post-match (similar to that found in other team-sports). Most disparities in sleep between match venues existed post-travel, with better sleep behaviour observed during the home condition. The differences in sleep patterns found in all three match formats were expected given the variations in format scheduling and duration. Although sleep medication was shown to promote better sleep, its long-term effectiveness was limited. The results promote the implementation of practical strategies aimed to reduce bedtime light-emitting technology use, late evening alcohol consumption and muscle pain. Inter-individual sleep behaviour was found between player roles, age, experience level and race. Moderate associations existed between sleep and markers of batting performance, specifically for the longer, strategic formats of the game. Conclusion: The current study provided new insight of the sleep behaviour in elite South African cricket players during competition. Individualized sleep monitoring practices are encouraged, with specific supervision over older, less experienced players as well as the racial minorities and allrounders of the team. The poor post-match sleep behaviour, together with the sleep and performance correlations, provide ideal opportunities for future interventions to focus on match recovery and the use sleep monitoring as a competitive advantage.
- Full Text:
- Date Issued: 2020
Investigating how the use of visual models can enhance the teaching of common fractions for conceptual understanding to Grade 8 learners
- Authors: Katenda, Aune Kashikuka
- Date: 2019
- Subjects: Fractions -- Study and teaching (Secondary)-- Namibia , Mathematics -- Study and teaching (Secondary)-- Namibia , Information visualization , Visual learning -- Case studies
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/96746 , vital:31314
- Description: The intention of this study was to explore how selected mathematics teachers used visual models to improve the teaching of common fractions for conceptual understanding to Grade 8 learners as a result of an intervention programme. This research study is part of the VIPROmaths project which seeks to research the effective use of visualisation processes in the mathematics classroom in South Africa, Namibia, Zambia, Switzerland and Germany. This study which adopted a case study of teachers in Khomas Region, Namibia, is informed by constructivist learning theory. The study is situated within the interpretive paradigm and a multi-phase mixed method research approach was used. It focussed on analysing the use of visual models when teaching fractions namely: area model, number line model and a set model. The data were collected through survey questionnaires, observation and recall interview. The survey was conducted with the forty three mathematics teachers, from twenty secondary schools in Khomas region. The survey gave an overview of the nature and the use of visual models in schools. Three teachers purposively selected from the survey participated in the intervention program and were observed while teaching and interviewed after their teaching. Data were qualitatively and quantitatively analysed. The findings of this study reveal that visualising fractions is one of the methods that can improve both teaching and learning by providing concrete evidence of otherwise abstract ideas and concepts. The teachers highlighted that models themselves guide learners through to the answer, as compared to working out solutions using symbols only. They further indicated that visual models improve learners’ motivation, enhances understanding of fractions and encourages full participation of learners in the lesson. The study also found that use of visual models encouraged participation and it also boosted learners thinking capability. Teachers in this study preferred to use the area model as they found this model easier and more user-friendly in comparison with the number line and the set models. Teachers did not use the set model because of its complexity. This study concludes that the use of visual models can help enhance the conceptual teaching and understanding of common fractions. It is hoped that the study contributes towards improving the quality teaching and learning of fractions in Namibia. Furthermore, it informs the teacher-training institutions in Namibia to integrate the use of visualisation in their training programmes to promote conceptual understanding of mathematics.
- Full Text:
- Date Issued: 2019
- Authors: Katenda, Aune Kashikuka
- Date: 2019
- Subjects: Fractions -- Study and teaching (Secondary)-- Namibia , Mathematics -- Study and teaching (Secondary)-- Namibia , Information visualization , Visual learning -- Case studies
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/96746 , vital:31314
- Description: The intention of this study was to explore how selected mathematics teachers used visual models to improve the teaching of common fractions for conceptual understanding to Grade 8 learners as a result of an intervention programme. This research study is part of the VIPROmaths project which seeks to research the effective use of visualisation processes in the mathematics classroom in South Africa, Namibia, Zambia, Switzerland and Germany. This study which adopted a case study of teachers in Khomas Region, Namibia, is informed by constructivist learning theory. The study is situated within the interpretive paradigm and a multi-phase mixed method research approach was used. It focussed on analysing the use of visual models when teaching fractions namely: area model, number line model and a set model. The data were collected through survey questionnaires, observation and recall interview. The survey was conducted with the forty three mathematics teachers, from twenty secondary schools in Khomas region. The survey gave an overview of the nature and the use of visual models in schools. Three teachers purposively selected from the survey participated in the intervention program and were observed while teaching and interviewed after their teaching. Data were qualitatively and quantitatively analysed. The findings of this study reveal that visualising fractions is one of the methods that can improve both teaching and learning by providing concrete evidence of otherwise abstract ideas and concepts. The teachers highlighted that models themselves guide learners through to the answer, as compared to working out solutions using symbols only. They further indicated that visual models improve learners’ motivation, enhances understanding of fractions and encourages full participation of learners in the lesson. The study also found that use of visual models encouraged participation and it also boosted learners thinking capability. Teachers in this study preferred to use the area model as they found this model easier and more user-friendly in comparison with the number line and the set models. Teachers did not use the set model because of its complexity. This study concludes that the use of visual models can help enhance the conceptual teaching and understanding of common fractions. It is hoped that the study contributes towards improving the quality teaching and learning of fractions in Namibia. Furthermore, it informs the teacher-training institutions in Namibia to integrate the use of visualisation in their training programmes to promote conceptual understanding of mathematics.
- Full Text:
- Date Issued: 2019
A comparison of exact string search algorithms for deep packet inspection
- Authors: Hunt, Kieran
- Date: 2018
- Subjects: Algorithms , Firewalls (Computer security) , Computer networks -- Security measures , Intrusion detection systems (Computer security) , Deep Packet Inspection
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/60629 , vital:27807
- Description: Every day, computer networks throughout the world face a constant onslaught of attacks. To combat these, network administrators are forced to employ a multitude of mitigating measures. Devices such as firewalls and Intrusion Detection Systems are prevalent today and employ extensive Deep Packet Inspection to scrutinise each piece of network traffic. Systems such as these usually require specialised hardware to meet the demand imposed by high throughput networks. Hardware like this is extremely expensive and singular in its function. It is with this in mind that the string search algorithms are introduced. These algorithms have been proven to perform well when searching through large volumes of text and may be able to perform equally well in the context of Deep Packet Inspection. String search algorithms are designed to match a single pattern to a substring of a given piece of text. This is not unlike the heuristics employed by traditional Deep Packet Inspection systems. This research compares the performance of a large number of string search algorithms during packet processing. Deep Packet Inspection places stringent restrictions on the reliability and speed of the algorithms due to increased performance pressures. A test system had to be designed in order to properly test the string search algorithms in the context of Deep Packet Inspection. The system allowed for precise and repeatable tests of each algorithm and then for their comparison. Of the algorithms tested, the Horspool and Quick Search algorithms posted the best results for both speed and reliability. The Not So Naive and Rabin-Karp algorithms were slowest overall.
- Full Text:
- Date Issued: 2018
- Authors: Hunt, Kieran
- Date: 2018
- Subjects: Algorithms , Firewalls (Computer security) , Computer networks -- Security measures , Intrusion detection systems (Computer security) , Deep Packet Inspection
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/60629 , vital:27807
- Description: Every day, computer networks throughout the world face a constant onslaught of attacks. To combat these, network administrators are forced to employ a multitude of mitigating measures. Devices such as firewalls and Intrusion Detection Systems are prevalent today and employ extensive Deep Packet Inspection to scrutinise each piece of network traffic. Systems such as these usually require specialised hardware to meet the demand imposed by high throughput networks. Hardware like this is extremely expensive and singular in its function. It is with this in mind that the string search algorithms are introduced. These algorithms have been proven to perform well when searching through large volumes of text and may be able to perform equally well in the context of Deep Packet Inspection. String search algorithms are designed to match a single pattern to a substring of a given piece of text. This is not unlike the heuristics employed by traditional Deep Packet Inspection systems. This research compares the performance of a large number of string search algorithms during packet processing. Deep Packet Inspection places stringent restrictions on the reliability and speed of the algorithms due to increased performance pressures. A test system had to be designed in order to properly test the string search algorithms in the context of Deep Packet Inspection. The system allowed for precise and repeatable tests of each algorithm and then for their comparison. Of the algorithms tested, the Horspool and Quick Search algorithms posted the best results for both speed and reliability. The Not So Naive and Rabin-Karp algorithms were slowest overall.
- Full Text:
- Date Issued: 2018
Donor-acceptor effects on the optical limiting properties of BODIPY dyes
- Authors: Hlatshwayo, Zweli Thabiso
- Date: 2018
- Subjects: Dyes and dyeing -- Chemistry , Photosensitizing compounds -- Therapeutic use , Cancer -- Photochemotherapy , Upconversion nanoparticles (UCNPs)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63368 , vital:28397
- Description: The main objectives of the research described in this thesis were firstly to synthesize and characterize a series of structurally related BODIPY dyes that are potentially suitable for use in applications, secondly to conjugate a carboxylic acid substituted BODIPY dye to amine-functionalized upconversion nanoparticles (UCNPs) through an amide bond to enable singlet oxygen production upon irradiation at 978 nm in the biological window for tissue penetration for biomedical applications, and thirdly to compare the nonlinear optical (NLO) properties of various BODIPY dyes to determine whether push-pull effects enhance their utility for optical limiting (OL) applications. Halogenated BODIPY cores with high singlet oxygen quantum yields were prepared, which absorb in the green portion of the visible region and making it difficult to treat deeper skin tumors in the context of photodynamic therapy (PDT) applications. UCNPs generally absorb in the near-infrared (NIR) region (978 nm), and this is advantageous because, this is where absorption by water, cells and tissues is minimized. NaYF4: Yb/Er/Gd UCNPs were synthesized, amine functionalized and successfully conjugated to a halogenated carboxylic acid functionalized BODIPY. This allowed for favorable Förster resonance energy transfer (FRET) since one of the emission wavelengths of the NaYF4: Yb/Er/Gd UCNPs overlaps with the main absorption band of the BODIPY at 540 nm. The conjugate was irradiated at 978 nm, but instability of the BODIPY dye was observed, which made singlet oxygen quantum yield determination impossible. An enhanced singlet oxygen quantum yield value was observed upon irradiation of the conjugate at 540 nm, suggesting that further studies of this system are warranted. The OL properties of BODIPY cores and dyes, which are π-extended at the 3,5-positions with styryl groups, were studied in a series of different organic solvents at 532 nm by using the z-scan technique on a nanosecond timescale. Many of the dyes were used to compare the effects of introducing electron donor and acceptor groups on the OL properties of the dyes. The dipole moments of these dyes were found to correlate with the OL response. The OL results indicate that BODIPY dyes with push-pull properties, which are π-extended at the 3,5-positions with styryl groups, can be considered as viable candidates for use in OL applications. The studies sought to establish the effect of ESA in the triplet manifold as compared to the singlet manifold in as far as the OL response is concerned. The most promising dyes were embedded in polystyrene thin films, and this was found to significantly enhance their OL properties.
- Full Text:
- Date Issued: 2018
- Authors: Hlatshwayo, Zweli Thabiso
- Date: 2018
- Subjects: Dyes and dyeing -- Chemistry , Photosensitizing compounds -- Therapeutic use , Cancer -- Photochemotherapy , Upconversion nanoparticles (UCNPs)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63368 , vital:28397
- Description: The main objectives of the research described in this thesis were firstly to synthesize and characterize a series of structurally related BODIPY dyes that are potentially suitable for use in applications, secondly to conjugate a carboxylic acid substituted BODIPY dye to amine-functionalized upconversion nanoparticles (UCNPs) through an amide bond to enable singlet oxygen production upon irradiation at 978 nm in the biological window for tissue penetration for biomedical applications, and thirdly to compare the nonlinear optical (NLO) properties of various BODIPY dyes to determine whether push-pull effects enhance their utility for optical limiting (OL) applications. Halogenated BODIPY cores with high singlet oxygen quantum yields were prepared, which absorb in the green portion of the visible region and making it difficult to treat deeper skin tumors in the context of photodynamic therapy (PDT) applications. UCNPs generally absorb in the near-infrared (NIR) region (978 nm), and this is advantageous because, this is where absorption by water, cells and tissues is minimized. NaYF4: Yb/Er/Gd UCNPs were synthesized, amine functionalized and successfully conjugated to a halogenated carboxylic acid functionalized BODIPY. This allowed for favorable Förster resonance energy transfer (FRET) since one of the emission wavelengths of the NaYF4: Yb/Er/Gd UCNPs overlaps with the main absorption band of the BODIPY at 540 nm. The conjugate was irradiated at 978 nm, but instability of the BODIPY dye was observed, which made singlet oxygen quantum yield determination impossible. An enhanced singlet oxygen quantum yield value was observed upon irradiation of the conjugate at 540 nm, suggesting that further studies of this system are warranted. The OL properties of BODIPY cores and dyes, which are π-extended at the 3,5-positions with styryl groups, were studied in a series of different organic solvents at 532 nm by using the z-scan technique on a nanosecond timescale. Many of the dyes were used to compare the effects of introducing electron donor and acceptor groups on the OL properties of the dyes. The dipole moments of these dyes were found to correlate with the OL response. The OL results indicate that BODIPY dyes with push-pull properties, which are π-extended at the 3,5-positions with styryl groups, can be considered as viable candidates for use in OL applications. The studies sought to establish the effect of ESA in the triplet manifold as compared to the singlet manifold in as far as the OL response is concerned. The most promising dyes were embedded in polystyrene thin films, and this was found to significantly enhance their OL properties.
- Full Text:
- Date Issued: 2018
Periglacial landforms of the Ahlmannryggen and Jutulsessen areas of western Dronning Maud land, Antarctica
- Authors: Wilmot, Nicola Frances
- Date: 2018
- Subjects: Periglacial processes Antarctica Queen Maud Land , Geomorphology Antarctica Queen Maud Land , Permafrost Antarctica Queen Maud Land , Freezes (Meteorology) Antarctica Queen Maud Land , Thawing Antarctica Queen Maud Land
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/61535 , vital:28034
- Description: Periglacial landforms are a common occurrence in Ahlmannryggen and Jutulsessen areas of western Dronning Maud land (WDML). Classification and formation of these landforms were disputed in literature. In Antarctica information on periglacial landforms is limited or confined to a specific landform. Thus a holistic approach was taken when investigating the periglacial landforms found in WDML. An overview of the existing knowledge base on periglacial landforms in WDML was given which was coupled with the analysis of archival data. The landforms found in this area were patterned ground, openwork block deposits (OBD), rock glaciers, terraces, a pronival rampart and lake ice blisters. With patterned ground being the common periglacial landform in WDML, heave monitoring was used where time-lapse videos were used to investigate the formation processes in patterned ground. From consolidating existing knowledge as well as adding new knowledge on the formation of periglacial landforms, it is clear that the landforms in Antarctica should not be compared to other examples, especially examples from the northern hemisphere. Further research in the formation of periglacial landforms is needed and can be further enhanced with more extensive use of the heave monitoring method in future research.
- Full Text:
- Date Issued: 2018
- Authors: Wilmot, Nicola Frances
- Date: 2018
- Subjects: Periglacial processes Antarctica Queen Maud Land , Geomorphology Antarctica Queen Maud Land , Permafrost Antarctica Queen Maud Land , Freezes (Meteorology) Antarctica Queen Maud Land , Thawing Antarctica Queen Maud Land
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/61535 , vital:28034
- Description: Periglacial landforms are a common occurrence in Ahlmannryggen and Jutulsessen areas of western Dronning Maud land (WDML). Classification and formation of these landforms were disputed in literature. In Antarctica information on periglacial landforms is limited or confined to a specific landform. Thus a holistic approach was taken when investigating the periglacial landforms found in WDML. An overview of the existing knowledge base on periglacial landforms in WDML was given which was coupled with the analysis of archival data. The landforms found in this area were patterned ground, openwork block deposits (OBD), rock glaciers, terraces, a pronival rampart and lake ice blisters. With patterned ground being the common periglacial landform in WDML, heave monitoring was used where time-lapse videos were used to investigate the formation processes in patterned ground. From consolidating existing knowledge as well as adding new knowledge on the formation of periglacial landforms, it is clear that the landforms in Antarctica should not be compared to other examples, especially examples from the northern hemisphere. Further research in the formation of periglacial landforms is needed and can be further enhanced with more extensive use of the heave monitoring method in future research.
- Full Text:
- Date Issued: 2018
Observing and evaluating creative mathematical reasoning through selected VITALmaths video clips and collaborative argumentation
- Authors: Kellen, Matthew Earl
- Date: 2017
- Subjects: Mathematics Study and teaching (Secondary) South Africa Grahamstown , Mathematics Study and teaching (Secondary) Audio-visual aids , Reasoning , Mathematical ability
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/6107 , vital:21032
- Description: Creative mathematical reasoning is a definition that the NCS policies allude to when they indicate the necessity for students to, “identify and solve problems and make decisions using critical and creative thinking.”(NCS, 2011: 9). Silver (1997) and Lithner (2008) focus on creativity of reasoning in terms of the flexibility, fluency and novelty in which one approaches a mathematical problem. Learners who can creatively select appropriate strategies that are mathematically founded, and justify their answers use creative mathematical reasoning. This research uses Visual Technology for the Autonomous Learning of Mathematics (VITALmaths) video clips that pose mathematics problems to stimulate articulated reasoning among small multi-age, multi-ability Grade 9 peer groups. Using VITALmaths clips that pose visual and open-ended task, set the stage for collaborative argumentation between peers. This study observes creative mathematical reasoning in two ways: Firstly by observing the interaction between peers in the process of arriving at an answer, and secondly by examining the end product of the peer group’s justification of their solution. (Ball & Bass, 2003) Six grade 8 and 9 learners from no-fee public schools in the township of Grahamstown, South Africa were selected for this case study. Participants were a mixed ability, mixed gendered, sample group from an after-school programme which focused on creating a space for autonomous learning. The six participants were split into two groups and audio and video recorded as they solved selected VITALmaths tasks and presented their evidence and solutions to the tasks. Audio and video recordings and written work were used to translate, transcribe, and code participant interactions according to a framework adapted from Krummheuer (2007) and Lithner (2008) and Silver (1997) and Toulmin (1954). This constituted the analysis of the process of creative mathematical reasoning. Group presentations of evidence and solutions to the VITALmaths tasks, were used in conjunction with an evaluation framework adapted from Lithner (2008) and Campos (2010). This was the product analysis of creative mathematical reasoning. This research found that there was significant evidence of creative mathematical reasoning in the process and product evaluation of group interactions and solutions. Process analysis showed that participants were very active, engaged, and creative in their participation, but struggled to integrate and implement ideas cohesively. Product analysis similarly showed that depth and concentration of strategies implemented are key to correct and exhaustive mathematically grounded solutions.
- Full Text:
- Date Issued: 2017
- Authors: Kellen, Matthew Earl
- Date: 2017
- Subjects: Mathematics Study and teaching (Secondary) South Africa Grahamstown , Mathematics Study and teaching (Secondary) Audio-visual aids , Reasoning , Mathematical ability
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/6107 , vital:21032
- Description: Creative mathematical reasoning is a definition that the NCS policies allude to when they indicate the necessity for students to, “identify and solve problems and make decisions using critical and creative thinking.”(NCS, 2011: 9). Silver (1997) and Lithner (2008) focus on creativity of reasoning in terms of the flexibility, fluency and novelty in which one approaches a mathematical problem. Learners who can creatively select appropriate strategies that are mathematically founded, and justify their answers use creative mathematical reasoning. This research uses Visual Technology for the Autonomous Learning of Mathematics (VITALmaths) video clips that pose mathematics problems to stimulate articulated reasoning among small multi-age, multi-ability Grade 9 peer groups. Using VITALmaths clips that pose visual and open-ended task, set the stage for collaborative argumentation between peers. This study observes creative mathematical reasoning in two ways: Firstly by observing the interaction between peers in the process of arriving at an answer, and secondly by examining the end product of the peer group’s justification of their solution. (Ball & Bass, 2003) Six grade 8 and 9 learners from no-fee public schools in the township of Grahamstown, South Africa were selected for this case study. Participants were a mixed ability, mixed gendered, sample group from an after-school programme which focused on creating a space for autonomous learning. The six participants were split into two groups and audio and video recorded as they solved selected VITALmaths tasks and presented their evidence and solutions to the tasks. Audio and video recordings and written work were used to translate, transcribe, and code participant interactions according to a framework adapted from Krummheuer (2007) and Lithner (2008) and Silver (1997) and Toulmin (1954). This constituted the analysis of the process of creative mathematical reasoning. Group presentations of evidence and solutions to the VITALmaths tasks, were used in conjunction with an evaluation framework adapted from Lithner (2008) and Campos (2010). This was the product analysis of creative mathematical reasoning. This research found that there was significant evidence of creative mathematical reasoning in the process and product evaluation of group interactions and solutions. Process analysis showed that participants were very active, engaged, and creative in their participation, but struggled to integrate and implement ideas cohesively. Product analysis similarly showed that depth and concentration of strategies implemented are key to correct and exhaustive mathematically grounded solutions.
- Full Text:
- Date Issued: 2017
The design of a school model rural school for the rural Transkei, province of the Eastern Cape
- Authors: Van der Walt, Louwrens
- Date: 2016
- Subjects: School buildings -- South Africa -- Eastern Cape -- Designs and plans Elementary school buildings -- South Africa -- Transkei -- Design and construction , School buildings -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/15422 , vital:28243
- Description: This treatise investigates the issues and processes involved in the school provision systems used to provide schools in the former Transkei area of the Eastern Cape. The purpose of the treatise is to better understand the contextual, spatial, physical and theoretical nature of the rural areas at present of the Transkei and how these provision systems have responded to this. From this understanding a set of architectural issues are identified from which an appropriate building is designed, along with an appropriate provision system. Several precedents of provision systems used in the Transkei are investigated, along with several architectural precedents according to their particular responses. This is done in order to uncover the spatial relationships, material and physical aspects, as well as theoretical issues, from which an appropriate architectural language can be identified. The need for the provision systems to be investigated is established along with the identification of four sites within the Transkei area which are to be investigated. The selected site on which the design will be implemented is located on a tar road between Dutya and Willowvale as it has similar attributes to most existing school sites in the former Transkei and therefore functions as a good testing ground for developing an appropriate design that can be implemented on multiple sites. In order for the design of the provision system and building to be appropriate, an in-depth contextual analysis is done on the Transkei area as a whole from which a set of constraints and informants are derived to better guide the design.
- Full Text:
- Date Issued: 2016
- Authors: Van der Walt, Louwrens
- Date: 2016
- Subjects: School buildings -- South Africa -- Eastern Cape -- Designs and plans Elementary school buildings -- South Africa -- Transkei -- Design and construction , School buildings -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/15422 , vital:28243
- Description: This treatise investigates the issues and processes involved in the school provision systems used to provide schools in the former Transkei area of the Eastern Cape. The purpose of the treatise is to better understand the contextual, spatial, physical and theoretical nature of the rural areas at present of the Transkei and how these provision systems have responded to this. From this understanding a set of architectural issues are identified from which an appropriate building is designed, along with an appropriate provision system. Several precedents of provision systems used in the Transkei are investigated, along with several architectural precedents according to their particular responses. This is done in order to uncover the spatial relationships, material and physical aspects, as well as theoretical issues, from which an appropriate architectural language can be identified. The need for the provision systems to be investigated is established along with the identification of four sites within the Transkei area which are to be investigated. The selected site on which the design will be implemented is located on a tar road between Dutya and Willowvale as it has similar attributes to most existing school sites in the former Transkei and therefore functions as a good testing ground for developing an appropriate design that can be implemented on multiple sites. In order for the design of the provision system and building to be appropriate, an in-depth contextual analysis is done on the Transkei area as a whole from which a set of constraints and informants are derived to better guide the design.
- Full Text:
- Date Issued: 2016
Assessment of the quality of primary health care services rendered at Moses Mabida Clinic
- Authors: Tsetswa, Mncedisi Patrick
- Date: 2009
- Subjects: Primary health care -- South Africa , Health facilities
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8727 , http://hdl.handle.net/10948/880 , Primary health care -- South Africa , Health facilities
- Description: Health is a basic human right enshrined in the South African Constitution. It is the responsibility of government to ensure that the nation is healthy because good health is a prerequisite for social and economic development as well as an outcome of that process. Special attention on the healthcare needs of rural communities should be given because these communities were the worst affected by the legacy of the apartheid regime. Moses Mabida community is no exception. Since the advent of democracy, work has been done to ensure that adequate primary health care services are delivered to previously disadvantaged communities such as Moses Mabida. To monitor progress on health care service delivery, evaluation of these services is needed. The evaluation of these services will help identify the strengths and weaknesses so as to come up with quality improvement strategies, hence this study. This study takes form of an assessment survey involving a literature review and a survey of members of the Moses Mabida community who depend on the clinic for their health care needs. The literature identified best practice models of primary health care and these were used as an analytic tool to determine to what extent the primary health care services at Moses Mabida comply with national and international standards. It has been shown that the primary health care services at Moses Mabida Clinic largely comply with national and international standards although several recommendations have been presented for consideration.
- Full Text:
- Date Issued: 2009
- Authors: Tsetswa, Mncedisi Patrick
- Date: 2009
- Subjects: Primary health care -- South Africa , Health facilities
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8727 , http://hdl.handle.net/10948/880 , Primary health care -- South Africa , Health facilities
- Description: Health is a basic human right enshrined in the South African Constitution. It is the responsibility of government to ensure that the nation is healthy because good health is a prerequisite for social and economic development as well as an outcome of that process. Special attention on the healthcare needs of rural communities should be given because these communities were the worst affected by the legacy of the apartheid regime. Moses Mabida community is no exception. Since the advent of democracy, work has been done to ensure that adequate primary health care services are delivered to previously disadvantaged communities such as Moses Mabida. To monitor progress on health care service delivery, evaluation of these services is needed. The evaluation of these services will help identify the strengths and weaknesses so as to come up with quality improvement strategies, hence this study. This study takes form of an assessment survey involving a literature review and a survey of members of the Moses Mabida community who depend on the clinic for their health care needs. The literature identified best practice models of primary health care and these were used as an analytic tool to determine to what extent the primary health care services at Moses Mabida comply with national and international standards. It has been shown that the primary health care services at Moses Mabida Clinic largely comply with national and international standards although several recommendations have been presented for consideration.
- Full Text:
- Date Issued: 2009
The perceptions of grade eight and nine learners of a life skills programme on HIV/AIDS, sexually transmitted infections, rape and child abuse
- Authors: Lambert, Tania
- Date: 2005
- Subjects: AIDS (Disease) -- Study and teaching (Elementary) -- South Africa -- Evaluation , AIDS (Disease) -- South Africa -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9854 , http://hdl.handle.net/10948/390 , http://hdl.handle.net/10948/d1005827 , AIDS (Disease) -- Study and teaching (Elementary) -- South Africa -- Evaluation , AIDS (Disease) -- South Africa -- Prevention
- Description: Worldwide millions of children are victims of neglect and physical and mental harm, including sexual abuse and exploitation. South Africa, however, is widely believed to have not only one of the highest incidences of rape in the world, but also one of the highest levels of Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) transmission. With research findings showing that HIV and other Sexually Transmitted Infections (STIs) are rapidly increasing globally, young people are, and continue to be, at the forefront of the AIDS pandemic. Therefore, it is suggested that prevention programmes should be aimed particularly at the young. Schools have specifically been recognized as the setting for preventative Life Skills Programmes, having the potential to reach billions of children worldwide. The aim of this study is to explore and describe the perceptions of grade eight and nine learners with regard to the Life Skills Programme that focuses on HIV/AIDS and STI's, rape and child abuse education in the Port Elizabeth region. In order to fulfil the above aim, a qualitative study was undertaken within an exploratory descriptive approach. A non-probability sample of four schools was selected. Focus groups, utilising an unstructured interview, were used to gather qualitative data on the learners' perceptions of the Life Skills Programme. The focus groups consisted of 10 - 12 grade eight and nine learners who were selected using simple random sampling. The data was thematically analysed using Tesch's approach. The major findings of the present study, based on the six general themes, include the following: 1. Most of the learners perceived the educators, as well as the teaching methods utilised by the educators, positively. 2. Although the learners perceived the presenters of the Life Skills Programme positively, it was suggested that teachers, health care professionals, family members and peers should be involved in presenting the Life Skills Programme. 3. Learners reported various levels of comfort discussing different topics presented in the Life Skills Programme. 4. Learners of all the schools perceived the Life Skills Programme to be very relevant. 5. Learners recommended that more children, especially children from deprived communities, should be included in the programme. In addition, learners felt that counselling services should be available in conjunction with the Life Skills Programme. 6. Differences were noted in completing the first and the second questionnaire. Learners reported that they felt more comfortable completing the second questionnaire. They perceived the interviewing process positively.
- Full Text:
- Date Issued: 2005
- Authors: Lambert, Tania
- Date: 2005
- Subjects: AIDS (Disease) -- Study and teaching (Elementary) -- South Africa -- Evaluation , AIDS (Disease) -- South Africa -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9854 , http://hdl.handle.net/10948/390 , http://hdl.handle.net/10948/d1005827 , AIDS (Disease) -- Study and teaching (Elementary) -- South Africa -- Evaluation , AIDS (Disease) -- South Africa -- Prevention
- Description: Worldwide millions of children are victims of neglect and physical and mental harm, including sexual abuse and exploitation. South Africa, however, is widely believed to have not only one of the highest incidences of rape in the world, but also one of the highest levels of Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) transmission. With research findings showing that HIV and other Sexually Transmitted Infections (STIs) are rapidly increasing globally, young people are, and continue to be, at the forefront of the AIDS pandemic. Therefore, it is suggested that prevention programmes should be aimed particularly at the young. Schools have specifically been recognized as the setting for preventative Life Skills Programmes, having the potential to reach billions of children worldwide. The aim of this study is to explore and describe the perceptions of grade eight and nine learners with regard to the Life Skills Programme that focuses on HIV/AIDS and STI's, rape and child abuse education in the Port Elizabeth region. In order to fulfil the above aim, a qualitative study was undertaken within an exploratory descriptive approach. A non-probability sample of four schools was selected. Focus groups, utilising an unstructured interview, were used to gather qualitative data on the learners' perceptions of the Life Skills Programme. The focus groups consisted of 10 - 12 grade eight and nine learners who were selected using simple random sampling. The data was thematically analysed using Tesch's approach. The major findings of the present study, based on the six general themes, include the following: 1. Most of the learners perceived the educators, as well as the teaching methods utilised by the educators, positively. 2. Although the learners perceived the presenters of the Life Skills Programme positively, it was suggested that teachers, health care professionals, family members and peers should be involved in presenting the Life Skills Programme. 3. Learners reported various levels of comfort discussing different topics presented in the Life Skills Programme. 4. Learners of all the schools perceived the Life Skills Programme to be very relevant. 5. Learners recommended that more children, especially children from deprived communities, should be included in the programme. In addition, learners felt that counselling services should be available in conjunction with the Life Skills Programme. 6. Differences were noted in completing the first and the second questionnaire. Learners reported that they felt more comfortable completing the second questionnaire. They perceived the interviewing process positively.
- Full Text:
- Date Issued: 2005
Configuring convergence : southern African websites looking at American experience
- Authors: Berger, Guy
- Date: 2001
- Language: English
- Type: text
- Identifier: vital:535 , http://hdl.handle.net/10962/d1008553 , ISBN 0-86810-379-9
- Description: I want the Web to win. Africa’s news sites on the Internet need to succeed and survive. They’re a small guarantee against global marginalisation, and a critical intersection across our continent’s domestic divides. But the outlook is not good. At a conference I went to in Berkeley in April 2001, a venture capitalist had this to say: "If I were to make a speech on when there’ll be investment in new media again, it would be a rather short topic." The alarming closures and retrenchments at news websites in the USA are sending scary signals to our fledgling efforts back here. Starting and growing media enterprises of any sort in African conditions has never been easy. Long starved of investment, our cyberpublishing now faces even greater pressures as old media – newspapers, radio and TV – try to make ends meet under mounting threats. Advertising is shrinking, local costs are rising and currency falls are fuelling the price of imported production factors. Consumers have less cash to spend. Governments are giving even greater problems in some cases. Will we still be here in the morning, and in what condition? This booklet suggests the way forward is for new media to converge with selected partners, old media and new.
- Full Text:
- Date Issued: 2001
- Authors: Berger, Guy
- Date: 2001
- Language: English
- Type: text
- Identifier: vital:535 , http://hdl.handle.net/10962/d1008553 , ISBN 0-86810-379-9
- Description: I want the Web to win. Africa’s news sites on the Internet need to succeed and survive. They’re a small guarantee against global marginalisation, and a critical intersection across our continent’s domestic divides. But the outlook is not good. At a conference I went to in Berkeley in April 2001, a venture capitalist had this to say: "If I were to make a speech on when there’ll be investment in new media again, it would be a rather short topic." The alarming closures and retrenchments at news websites in the USA are sending scary signals to our fledgling efforts back here. Starting and growing media enterprises of any sort in African conditions has never been easy. Long starved of investment, our cyberpublishing now faces even greater pressures as old media – newspapers, radio and TV – try to make ends meet under mounting threats. Advertising is shrinking, local costs are rising and currency falls are fuelling the price of imported production factors. Consumers have less cash to spend. Governments are giving even greater problems in some cases. Will we still be here in the morning, and in what condition? This booklet suggests the way forward is for new media to converge with selected partners, old media and new.
- Full Text:
- Date Issued: 2001
An assessment of a new personality measure of authoritarianism in the South African context
- Authors: Léger, Paul
- Date: 1992
- Subjects: Authoritarianism (Personality trait) -- Research , Authoritarianism -- Research -- South Africa , Psychological tests -- Research , Personality tests -- Research
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3007 , http://hdl.handle.net/10962/d1002516 , Authoritarianism (Personality trait) -- Research , Authoritarianism -- Research -- South Africa , Psychological tests -- Research , Personality tests -- Research
- Description: The aim of the research was to assess the psychometric properties of Altemeyer's (1981) Right-Wing Authoritarianism scale (RWA scale)- developed in response to identified methodological weaknesses in personality measures of authoritarianism to date - within a South African setting. A modified version of the 24-item attitudinal scale, together with a demographic questionnaire was administered to a white and black sample of South African university students. Subsequent psychometric analysis of the data indicated that the scale was a significantly less powerful measure of authoritarianism in a cross-cultural context, than originally hoped for. Not only did the analysis show an absence of psychometric equivalence but revealed substantial problems within the content of the scale itself. An ensuing discussion of these findings situated the debate within a broader theoretical context. It was argued that the RWA scale, and its underpinning conceptualization, although possibly comprising a methodological refinement over existing measures of authoritarianism, did not constitute grounds for a viable approach to research on authoritarianism in the South African context. It was concluded that a model of authoritarianism resting on the assumptions of positivistic psychology, inevitably failed to account for the social and political dynamics of a changing society. As a socially relevant enterprise, it was suggested that the debate on authoritarianism be extended beyond the confines of individualistic psychology and research priority directed instead to the crucial role of societal factors giving rise to the individual manifestation of the phenomenon.
- Full Text:
- Date Issued: 1992
- Authors: Léger, Paul
- Date: 1992
- Subjects: Authoritarianism (Personality trait) -- Research , Authoritarianism -- Research -- South Africa , Psychological tests -- Research , Personality tests -- Research
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3007 , http://hdl.handle.net/10962/d1002516 , Authoritarianism (Personality trait) -- Research , Authoritarianism -- Research -- South Africa , Psychological tests -- Research , Personality tests -- Research
- Description: The aim of the research was to assess the psychometric properties of Altemeyer's (1981) Right-Wing Authoritarianism scale (RWA scale)- developed in response to identified methodological weaknesses in personality measures of authoritarianism to date - within a South African setting. A modified version of the 24-item attitudinal scale, together with a demographic questionnaire was administered to a white and black sample of South African university students. Subsequent psychometric analysis of the data indicated that the scale was a significantly less powerful measure of authoritarianism in a cross-cultural context, than originally hoped for. Not only did the analysis show an absence of psychometric equivalence but revealed substantial problems within the content of the scale itself. An ensuing discussion of these findings situated the debate within a broader theoretical context. It was argued that the RWA scale, and its underpinning conceptualization, although possibly comprising a methodological refinement over existing measures of authoritarianism, did not constitute grounds for a viable approach to research on authoritarianism in the South African context. It was concluded that a model of authoritarianism resting on the assumptions of positivistic psychology, inevitably failed to account for the social and political dynamics of a changing society. As a socially relevant enterprise, it was suggested that the debate on authoritarianism be extended beyond the confines of individualistic psychology and research priority directed instead to the crucial role of societal factors giving rise to the individual manifestation of the phenomenon.
- Full Text:
- Date Issued: 1992
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