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Sexual attraction and mating compatibility between Thaumatotibia leucotreta populations and implications for semiochemical dependent technologies

  • Authors: Upfold, Jennifer Kate
  • Date: 2020
  • Subjects: Cryptophlebia leucotreta -- South Africa , Cryptophlebia leucotreta -- Reproduction , Citrus -- Disease and pests -- Control -- South Africa , Insect sterilization -- South Africa , Pheromones , Pheromone traps
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/148526 , vital:38747
  • Description: False codling moth (FCM), Thaumatotibia leucotreta (Meyrick), is the most important pest for the cultivation of citrus in South Africa. False codling moth is indigenous to southern Africa and is a regulated pest of many international markets for phytosanitary concerns. Considerable research efforts have been invested in the past decades to develop semiochemcial technologies, such as monitoring with sex pheromones, attract-and-kill, mating disruption and the sterile insect technique. One of the potential obstacles identified with semiochemical control is the differences in the ratio of the compounds comprising the sex pheromone at different geographical locations, resulting in what is known as regional attraction. This has been identified in FCM populations from three different countries, however, regional attraction within South African FCM populations was unknown. Therefore, the study assessed the genetic integrity of five laboratory-reared FCM populations originating from geographically isolated populations in South Africa using the AFLP technique in order to assess regional attractiveness within the country. The results found isolated populations from Addo, Citrusdal, Marble Hall, Nelspruit and a fifth group found to be closely related to Addo and Citrusdal called the ‘Old’ colony. These five genetically isolated populations as well as a population from Xsit (Pty) Ltd, used for the sterile insect technique (SIT), were used in regional attractiveness trials. Males were significantly (P = <0.05) more attracted to females originating from the same population. No significant attraction could be determined from the sterile males, as the recapture rates in the trap were too low. Furthermore, regional attractiveness was assessed through choice/ no-choice mating compatibility trials. Significant sexual isolation (ISI) occurred between mating combinations Addo × Nelspruit (ISI = 0,13; t2 = 6.23; p = 0.02), Addo × Marble Hall (ISI = 0,11; t2 = 4.72; p = 0.04), Citrusdal × Nelspruit (ISI = 0,11; t2 = 4.95; p = 0.04), and Citrusdal × Marble Hall (ISI = 0,12; t2 = 4.31; p = 0.04). In these combinations, Addo and Citrusdal males were found to have outcompeted Nelspruit and Marble Hall males for more mating events. Significant sexual isolation was also recorded for Sterile × Marble Hall (ISI = 0.12; t2 = 4.98; p =0.01) and Sterile × Citrusdal (ISI = 0.13; t2 = 3.96; p = 0.01) populations. The male relative performance index was significant in both combinations, indicating that non-sterile laboratory males outcompeted the sterile males in these two combinations. When given no choice, evaluated as spermatophore transfer/ female/ 48h, all males (including sterile) were successful in transferring spermatophores to all FCM populations, with no significant differences. These results indicate that there may be incipient pre-isolation mechanisms affected by local natural selection, resulting in localised sexual attraction via differences in the sex pheromone ratios. These findings provide important information for semiochemical technologies and the implication of these results with regard to monitoring with sex pheromones, attract-and-kill, mating disruption and sterile insect technique are discussed.
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  • Date Issued: 2020

Social media and brand image: a longitudinal study of Eastern Cape universities

  • Authors: Mnqeta, Lusanda
  • Date: 2020
  • Subjects: Multivariate analysis -- Graphic methods , Branding (Marketing) -- South Africa , Chernoff faces , Social media -- South Africa , Universities and colleges -- South Africa -- Marketing , Universities and colleges -- South Africa -- Marketing -- Case studies
  • Language: English
  • Type: text , Thesis , Masters , MBA
  • Identifier: http://hdl.handle.net/10962/143959 , vital:38298
  • Description: It is important for Higher Education Institutions to have marketing strategies that focus on understanding the customer needs in the 21st century. The rapid growth of the internet and the Web 2.0 have led individuals and organisations into applying social media as a branding and communication tool. Hence this study focused on comparing the influence of social media on four Eastern Cape universities in relation to social media metrics and visually demonstrated through the computer-generated human face, the Chernoff faces. Using diary and literature study, the study adopted a case study research design. The researcher sampled four universities using a purposeful sampling technique. Chernoff faces were used to enhance the ability of the reader to immediately understand significant occurrences based on social media metric indicators. To demonstrate multivariate data, the faces brought an original method of expressing complex data as opposed to traditional methods. The study found that Brand management and Resource-Based Theory (RBT) plays a pivotal role in social media marketing as this can lead to organisations having a competitive advantage. The study recommended that strategies to utilise social media as a resource should be put in place to lead to competitive advantage, as suggested by the Resource-based theory. The study concluded that various social media factors can influence the brand image of universities, positively (going to buy) and negatively (never going to buy). Both positive and negative purchase intent are found to be an influential indicator on the brand as they are affected by customer satisfaction.
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  • Date Issued: 2020

Temporal patterns and seasonal variation in microplastic loads in the water column and in the tissues of consumers along the southern and south-eastern coasts of South Africa

The effectiveness of sandplay therapy with a Xhosa child

  • Authors: Snelgar, Orrin Glenn
  • Date: 2019
  • Subjects: Sandplay -- Therapeutic use -- Case studies -- South Africa , Play therapy -- Case studies -- South Africa , Child psychotherapy -- Case studies -- South Africa , Children, Black -- Psychology -- South Africa
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10962/179168 , vital:39876
  • Description: This case study sought to determine whether Kalffian Sandtray Therapy was effective with a Xhosa child. In the context of ongoing discussions surrounding evidence-based practice and culturally appropriate interventions, no published research has yet explored the effectiveness of this classical tool within this significant South African demographic. In an effort to address this omission, the research adopted a mixed methods approach where Kalffian analysis of the sandplay process was evaluated in conjunction with quantitative measures (the Strengths and Difficulties Questionnaire and the Young Person’s Clinical Outcomes in Routine Evaluation). The results of this triangulation revealed a complex picture of improved interpersonal functioning and stagnant (or worsened) emotional wellbeing after five sessions. Contextualised interpretations of these findings are discussed and recommendations made for future sandplay practice and research in the South African context.
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  • Date Issued: 2019

The potential significance of refugia in safeguarding Non-Timber Forest products under Harvesting

  • Authors: Mjoli, Nwabisa
  • Date: 2018
  • Subjects: Non-timber forest products -- South Africa -- Eastern Cape , Nature conservation -- South Africa -- Eastern Cape , Ecosystem management -- South Africa -- Eastern Cape
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/60596 , vital:27801
  • Description: Many rural households living in and adjacent to forests in South Africa harvest a variety of NonTimber Forest Products (NTFPs) such as wild fruits, fibre, fuelwood, seeds, medicine and bush meat for domestic use, sale and maintaining cultural values. To promote the continued availability of these NTFPs it is important that NTFPs are well maintained and that harvest offtake is sustainable, because if it is not, then the important livelihood function that they fulfil will be jeopardized over time. The role of refugia in conserving pockets of threatened species from overharvesting has rarely been considered. Building on Shackleton et al. (2015), six applications of the concept are considered: size refugia, spatial refugia, cultural/spiritual refugia and physical/habitat refugia. I examined the prevalence and type of refugia for NTFPs at three coastal sites in the Eastern Cape province of South Africa. This was done via several community focus group discussions at each site. Here I report on the role of refugia in offering some safeguard to NTFPs by assessing harvested and non-harvested sites of refugia as well as individual plant species by measuring population density, harvest damage and size class profile. Respondents from the focus group discussions perceived a general decline in the abundance of common, widely used species over the past five decades. Decreasing rainfall and distant farming activities was reported consistently by the majority of the respondents. The most common form of refugia was spatial refugia, followed by cultural/spiritual refugia and physical/habitat refugia. Only six species were identified to be in refugia, namely Cyperus congestus, Cyperus textillis, Millettia grandis, Olea europaea subsp. africana, Phoenix reclinata, and Ptaeroxylon obliquum. Population inventories revealed that regeneration and population densities of some NTFP species in the non-refuge site were adversely affected by harvesting. Populations in refuge sites generally had the largest size classes indicating a regeneration potential but likely to impact regeneration over time if pressures are maintained. Therefore, if refuge sites keep larger individuals, NTFP populations can be maintained. Few studies have critically analyzed the concept of refugia in relation to how NTFPs can be safeguarded and the practical implication of the refuge concept needs to be considered in conservation and strategies and population models.
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  • Date Issued: 2018

Habitat suitability and behaviour of springbok (Antidorcas marsupialis) at Augrabies Falls National Park, South Africa

  • Authors: Reid, Caroline
  • Date: 2005
  • Subjects: Springbok -- Habitat suitability index models -- South Africa -- Augrabies Falls National Park , Springbok -- Behavior -- South Africa -- Augrabies Falls National Park
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:11079 , http://hdl.handle.net/10948/362 , Springbok -- Habitat suitability index models -- South Africa -- Augrabies Falls National Park , Springbok -- Behavior -- South Africa -- Augrabies Falls National Park
  • Description: Habitat selection may be considered a behavioural consequence of an individual actively selecting where it lives or passively persisting in a certain habitat. There are a variety of approaches to assessing habitat selection, including relating densities to predefined habitats and the characteristics of these habitats, measuring the behaviour of animals within predefined habitats in order to assess the relative benefits to the animal and comparing these between habitats, and using optimality theory to allow the animal to provide measures of its preference for particular habitats or patches. Each approach provides different perspectives on an animal’s choice and use of habitat, with some approaches working more effectively with certain species or habitats than others. There have, however, been no attempts to apply all these approaches to a single species at a single site. The objective of this study was therefore to apply the three above-mentioned approaches to assess habitat use and quality to a single species, the springbok (Antidorcas marsupialis) at the Augrabies Falls National Park (AFNP), on the northern bank of the Orange River, in order to provide the basis for further work on comparing and integrating these approaches. The relative abundance of springbok in Augrabies Falls National park was used to develop a habitat suitability model for the park, and thus determine the habitat variables that influenced habitat suitability. Isodar analysis revealed information on the mechanisms underlying habitat preference. Behavioural models were developed to improve our understanding of how springbok behaviour changes in relation to the habitat, and incorporated the variables identified in the habitat suitability model. The different spatial and temporal scales influencing springbok habitat selection were determined using optimal foraging theory and giving-up densities. Springbok preferred open habitats providing high food quality. Springbok behaviour was related to the foraging and predation risk characteristics of the habitat, and springbok varied their temporal and spatial utilisation so as to minimise their risk of predation and maximise their food intake. The habitat suitability model, behaviour models and giving-up densities were compared for ease of use and applicability. Using giving-up densities to reveal habitat suitability had greater applicability and was both efficient and objective.
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  • Date Issued: 2005

A situation analysis of sex education and communication and the implications thereof for HIV/AIDS prevention work

  • Authors: Mankayi, Andiswa
  • Date: 2003
  • Subjects: Sex instruction , Safe sex in AIDS prevention , AIDS (Disease) -- South Africa -- Eastern Cape , AIDS (Disease) -- South Africa -- Eastern Cape -- Prevention
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3147 , http://hdl.handle.net/10962/d1007447 , Sex instruction , Safe sex in AIDS prevention , AIDS (Disease) -- South Africa -- Eastern Cape , AIDS (Disease) -- South Africa -- Eastern Cape -- Prevention
  • Description: This study explores the history of sex communication and education over a period of fifty years (1950 to the present), in a deep rural area of the Eastern Cape. It describes patterns of sex communication between peers, between siblings, between children and parents and between young people and other non-familial agencies within communities. Communication trends are traced from the period before contraception was introduced, through to the introduction of female birth control methods into the HIV/AIDS era where the focus has been on attempting to introduce condoms. Twelve semi-structured interviews and two four-person focus groups were conducted to gather information on how the participants acquired information about sexuality and their responses to the same. The findings of the present study suggest that the widespread use of injectable contraceptives has had a marked effect on the sexual culture of the community under investigation. It has led to the collapse of the regulatory practices which were previously in place. This in turn has significantly affected the sexual communication and negotiation context. Furthermore, it has had a determining influence on male involvement in sexual reproductive health matters and has created a poor context for the adoption of condoms as a prophylactic. There were no major changes in the sexual communication context within families and within communities in that education has always been limited to instructions to avoid pregnancy. Of note was a culture of collusion between adults and children surrounding sexuality, which absolved the parties involved in addressing sexuality. These factors are understood have mediated response to HIV/AIDS prevention efforts, and need to be taken into consideration in the development of sex communication and education programmes.
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  • Date Issued: 2003

WISC-R coding incidental recall, digit span and supraspan test performance in children aged 6 and 7

  • Authors: Avis, Cheryl Esme
  • Date: 1995
  • Subjects: Wechsler Intelligence Scale for Children
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3155 , http://hdl.handle.net/10962/d1007506 , Wechsler Intelligence Scale for Children
  • Description: The primary aim of this study was to develop age-related normative data for the WISC-R Digits Forward, Digits Backward, Digits Difference, Digit Supraspan, and Coding Incidental Recall (Immediate and 30' Delayed) tests for a non-clinical population of South African school children aged 6 and 7. The effects of sex, English versus Xhosa language, and white versus black race groups, were additional investigations. Subjects were randomly selected from three English speaking Grahamstown schools; level of education ranged from pre-school to Sub Standard B; English speaking subjects included predominantly white children, with a small proportion of coloured, Chinese and Indian children; Xhosa speaking children were all black. Interim normative data on all tests across two age groups (6 and 7) are presented, and are considered reliable and diagnostically useful in clinical neuropsychological assessment. There were no significant effects for age, sex, English versus Xhosa language or white versus black race groups, on any of the tests with the exception of Digits Backward which yielded marginally lower scores for black Subjects. Although the mean IQ estimate based on the Draw-A-Person test was equivalent across age, sex, English versus Xhosa language and white versus black race groups, an intelligence rating of subjects by teachers revealed that black subjects were evaluated significantly lower than white subjects. This suggests the presence of prejudicial racial attitudes amongst educators in these predominantly English speaking white schools.
  • Full Text:
  • Date Issued: 1995

A critical study of assessments made during a trial interview situation

  • Authors: Pons, A L
  • Date: 1951
  • Subjects: Interviewing
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3226 , http://hdl.handle.net/10962/d1013040
  • Description: At the end of 1948 the National Institute for Personnel Research (N.I.P.R.) organised a series of testing procedures for the selection of administrative trainees for a large industrial organisation. The fruitful results obtained by the British War Office and the Civil Service selection Boards in the application of approved techniques for similar purposes supplied the basis on which the battery of tests was constructed. While having regard for this established approach as well as the controlling influence imposed by the stipulations of the contract, the N.I.P.R. was able to devise a battery which provided scope for its specific interest in research. Intro., p. 1.
  • Full Text:
  • Date Issued: 1951
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