A laboratory simulation investigating the impact of sunglass tint on the catching performance of cricket fielders
- Authors: Nellemann, Stacy Amanda
- Date: 2022-04-06
- Subjects: Sunglasses , Cricket Physiological aspects , Cricket players , Glare , Vision , Contrast sensitivity (Vision) , Fielders (Cricket)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291281 , vital:56839
- Description: Background: Sunglasses are popularly worn by outdoor athletes such as cricketers. They are primarily worn to preserve ocular health due to the length of time exposed to the sun’s glare on the field. More recently, sunglasses are now worn for their purported performance-enhancing benefits supposedly allowing athletes to “see clearly, react faster and perform with confidence”. Fielders typically wear sunglasses, but it is rare to see the bowler or the batter wearing sunglasses although they are exposed to the same conditions. If sunglasses provide visual clarity for better reaction time, it is assumed this would also be beneficial for both batsmen and bowlers alike. It is interesting that although fielding plays a key role in the winning of a match, it has received very little research in comparison to the areas of batting and bowling. Research concerning sunglasses in the past has been concerned with its effect on ocular parameters such as colour vision and contrast sensitivity, with minimal research on their effect on performance, specifically on how different colour tints may affect performance such as catching in fielding. Objective: The purpose of this study was to compare the catching performance of fielders when wearing three different colour tints of sunglasses. Methods: Thirty male cricketers currently playing for Rhodes University or country districts sides in Makhanda, South Africa, who were non-habitual sunglass wearers were recruited for this study. An optician administered a pre-screening test to ensure participants did not have any visual defects that would affect the results, determining who was eligible to continue with the research project. Twenty-five participants qualified with a further four withdrawing during the experimentation phase due to personal reasons. Eligible participants were required to complete four testing sessions on separate days thereafter in which they wore a different colour tint at each session (clear, blue, G30 and red). These tints were randomised among participants. Participants were required to catch 18 balls projected from a bowling machine in each session. The number of balls caught as well as the quality of catch was recorded. At the end of the fourth session, participants were presented with a questionnaire investigating their subjective experience of the protocol and preference for any particular colour of lens. Results: Statistically significant results were found between the different colour lenses for the ocular parameters of contrast sensitivity and stereopsis tested by the optician. The red lens was found to be the best for contrast sensitivity with the blue lens performing the worst on this test. With regard to stereopsis, the G30 lens was the worst, with the red lens performing the best. The performance measures resulted in no significant difference between the different colour lenses both concerning the total number of catches taken as well as the quality of catch taken. The same result was found irrespective of the colour of lens used in each session. Data gathered from the questionnaire regarding visual comfort and target visibility resulted in the red lens being rated statistically worse than the other three conditions. In terms of personal preference, the G30 lens was rated statistically as the best coloured lens. Conclusion: It can be concluded that objectively there is no difference in performance between the three coloured lenses. Although from an ocular perspective, the red lens was expected to perform the best in terms of catching performance, there was no difference. Subjectively there was a strong preference among the players for the G30 lens with players strongly disliking the red lens. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Authors: Nellemann, Stacy Amanda
- Date: 2022-04-06
- Subjects: Sunglasses , Cricket Physiological aspects , Cricket players , Glare , Vision , Contrast sensitivity (Vision) , Fielders (Cricket)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291281 , vital:56839
- Description: Background: Sunglasses are popularly worn by outdoor athletes such as cricketers. They are primarily worn to preserve ocular health due to the length of time exposed to the sun’s glare on the field. More recently, sunglasses are now worn for their purported performance-enhancing benefits supposedly allowing athletes to “see clearly, react faster and perform with confidence”. Fielders typically wear sunglasses, but it is rare to see the bowler or the batter wearing sunglasses although they are exposed to the same conditions. If sunglasses provide visual clarity for better reaction time, it is assumed this would also be beneficial for both batsmen and bowlers alike. It is interesting that although fielding plays a key role in the winning of a match, it has received very little research in comparison to the areas of batting and bowling. Research concerning sunglasses in the past has been concerned with its effect on ocular parameters such as colour vision and contrast sensitivity, with minimal research on their effect on performance, specifically on how different colour tints may affect performance such as catching in fielding. Objective: The purpose of this study was to compare the catching performance of fielders when wearing three different colour tints of sunglasses. Methods: Thirty male cricketers currently playing for Rhodes University or country districts sides in Makhanda, South Africa, who were non-habitual sunglass wearers were recruited for this study. An optician administered a pre-screening test to ensure participants did not have any visual defects that would affect the results, determining who was eligible to continue with the research project. Twenty-five participants qualified with a further four withdrawing during the experimentation phase due to personal reasons. Eligible participants were required to complete four testing sessions on separate days thereafter in which they wore a different colour tint at each session (clear, blue, G30 and red). These tints were randomised among participants. Participants were required to catch 18 balls projected from a bowling machine in each session. The number of balls caught as well as the quality of catch was recorded. At the end of the fourth session, participants were presented with a questionnaire investigating their subjective experience of the protocol and preference for any particular colour of lens. Results: Statistically significant results were found between the different colour lenses for the ocular parameters of contrast sensitivity and stereopsis tested by the optician. The red lens was found to be the best for contrast sensitivity with the blue lens performing the worst on this test. With regard to stereopsis, the G30 lens was the worst, with the red lens performing the best. The performance measures resulted in no significant difference between the different colour lenses both concerning the total number of catches taken as well as the quality of catch taken. The same result was found irrespective of the colour of lens used in each session. Data gathered from the questionnaire regarding visual comfort and target visibility resulted in the red lens being rated statistically worse than the other three conditions. In terms of personal preference, the G30 lens was rated statistically as the best coloured lens. Conclusion: It can be concluded that objectively there is no difference in performance between the three coloured lenses. Although from an ocular perspective, the red lens was expected to perform the best in terms of catching performance, there was no difference. Subjectively there was a strong preference among the players for the G30 lens with players strongly disliking the red lens. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
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Wild Honeybush (Cyclopia intermedia) augmentation
- Authors: Michau, Paul-Luc
- Date: 2022-04-06
- Subjects: Herbal teas South Africa Joubertina , Tea trade South Africa Joubertina , Legumes Harvesting South Africa Joubertina , Legumes Planting South Africa Joubertina , Sustainable development South Africa Joubertina , Economic development Environmental aspects South Africa Joubertina , Natural resources Management South Africa Joubertina , Wild Honeybush (Cyclopia intermedia)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232635 , vital:50009
- Description: Honeybush (Cyclopia spp.) is an endemic legume to the fynbos region of South Africa, and certain species of the genus are used to make health tonics. There are growing international markets for such products and, currently, wild populations of the species Cyclopia intermedia are disproportionately relied upon to support this increase. Due to the sensitivity and ecological complexity of the resource, serious concerns about sustainability and regulation have arisen. The social landscape of the resource is equally as complex, and solutions for alleviating pressure on wild populations, such as reducing or banning harvesting, and switching to commercial cultivation are untenable in every case. A possible option, which has been used in the wildflower industry, is to augment (increase) wild populations by planting seeds or seedlings directly into the veld. The main focus of this research was to explore the viability of using augmentation to boost wild populations of C. intermedia through field trials. In support of this broad aim, research objectives addressed understanding the ecological habitat conditions of the species, quantifying the economic potential of augmentation, characterizing wild populations and conducting seed germination tests. GIS methods were used to locate sites most representative of natural conditions on different post-fire aged veld on a farm in the Kouga mountains. The study characterized habitat conditions by collecting soil and vegetation samples at plots where honeybush was present and absent within close proximity. Vegetation diversity was only slightly higher in presence plots, and no clear pattern between absence and presence plots was observed for soil properties. However, post-fire site age did significantly influence certain nutrient levels. The augmentation trial results indicate that seedlings have a much higher survival rate than seeds on average. Survival success varied unpredictably between plots where wild honeybush was already present and adjacent plots where it was absent. Post-fire site age influenced seedling growth and seed survival positively with the newly burnt plots showing the best growth rates overall. The cost-benefit analysis reveals that seeds are a better option as they require low-cost inputs and carry less risk, unlike seedlings which may have higher survival but are more expensive. The study recommends using trials to assess survival before choosing an option. Out of five natural populations of honeybush that were assessed only one showed seedling recruitment and three young plants were found between two of the other sites. Growth characteristics of populations showed expected variability based on site conditions and disturbance history. Growth appears to be rapid in the first-year post disturbance, thereafter slowing down. Average stem numbers and basal circumference increased concurrently for both harvested and unharvested populations. Due to the influence of natural conditions such as slope aspect and soil properties on plant morphology, it is best to compare harvested and unharvested individuals from the same site and preferably within close proximity to minimize such differences. Using seed sourced from the same parent population is critical to preserving genetic integrity and little is understood about germination characteristics from wild C. intermedia populations. The study tested germination rates between green and brown seed and alternative collection methods. When comparisons were done within farms on two occasions collection and seed colour did have a significant influence. Overall, the influence of which farm the seeds were collected from appeared to play the biggest role in determining germination. , Thesis (MSc) -- Faculty of Science, Geography, 2022
- Full Text:
- Authors: Michau, Paul-Luc
- Date: 2022-04-06
- Subjects: Herbal teas South Africa Joubertina , Tea trade South Africa Joubertina , Legumes Harvesting South Africa Joubertina , Legumes Planting South Africa Joubertina , Sustainable development South Africa Joubertina , Economic development Environmental aspects South Africa Joubertina , Natural resources Management South Africa Joubertina , Wild Honeybush (Cyclopia intermedia)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232635 , vital:50009
- Description: Honeybush (Cyclopia spp.) is an endemic legume to the fynbos region of South Africa, and certain species of the genus are used to make health tonics. There are growing international markets for such products and, currently, wild populations of the species Cyclopia intermedia are disproportionately relied upon to support this increase. Due to the sensitivity and ecological complexity of the resource, serious concerns about sustainability and regulation have arisen. The social landscape of the resource is equally as complex, and solutions for alleviating pressure on wild populations, such as reducing or banning harvesting, and switching to commercial cultivation are untenable in every case. A possible option, which has been used in the wildflower industry, is to augment (increase) wild populations by planting seeds or seedlings directly into the veld. The main focus of this research was to explore the viability of using augmentation to boost wild populations of C. intermedia through field trials. In support of this broad aim, research objectives addressed understanding the ecological habitat conditions of the species, quantifying the economic potential of augmentation, characterizing wild populations and conducting seed germination tests. GIS methods were used to locate sites most representative of natural conditions on different post-fire aged veld on a farm in the Kouga mountains. The study characterized habitat conditions by collecting soil and vegetation samples at plots where honeybush was present and absent within close proximity. Vegetation diversity was only slightly higher in presence plots, and no clear pattern between absence and presence plots was observed for soil properties. However, post-fire site age did significantly influence certain nutrient levels. The augmentation trial results indicate that seedlings have a much higher survival rate than seeds on average. Survival success varied unpredictably between plots where wild honeybush was already present and adjacent plots where it was absent. Post-fire site age influenced seedling growth and seed survival positively with the newly burnt plots showing the best growth rates overall. The cost-benefit analysis reveals that seeds are a better option as they require low-cost inputs and carry less risk, unlike seedlings which may have higher survival but are more expensive. The study recommends using trials to assess survival before choosing an option. Out of five natural populations of honeybush that were assessed only one showed seedling recruitment and three young plants were found between two of the other sites. Growth characteristics of populations showed expected variability based on site conditions and disturbance history. Growth appears to be rapid in the first-year post disturbance, thereafter slowing down. Average stem numbers and basal circumference increased concurrently for both harvested and unharvested populations. Due to the influence of natural conditions such as slope aspect and soil properties on plant morphology, it is best to compare harvested and unharvested individuals from the same site and preferably within close proximity to minimize such differences. Using seed sourced from the same parent population is critical to preserving genetic integrity and little is understood about germination characteristics from wild C. intermedia populations. The study tested germination rates between green and brown seed and alternative collection methods. When comparisons were done within farms on two occasions collection and seed colour did have a significant influence. Overall, the influence of which farm the seeds were collected from appeared to play the biggest role in determining germination. , Thesis (MSc) -- Faculty of Science, Geography, 2022
- Full Text:
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