A comparison of the views of South African and American photojournalists to the digital manipulation of news photographs
- Authors: Cass, Taryn May
- Date: 1999
- Subjects: Photojournalists , Photojournalism , Digital media -- Management , Photography -- Digital techniques , Digital media , Photojournalism -- Moral and ethical aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3420 , http://hdl.handle.net/10962/d1002873 , Photojournalists , Photojournalism , Digital media -- Management , Photography -- Digital techniques , Digital media , Photojournalism -- Moral and ethical aspects
- Description: Digital technology has now become pervasive at most publications in South Africa and in America. Pictures are routinely digitised by publications for ease of handling in the layout process, and this makes it relatively easy to alter or manipulate the pictures using computer software programmes. This thesis attempts to gauge the views of South African photojournalists about the digital manipulation of news photographs, and compare these to the views of American photojournalists. It is based on the hypothesis that South African and American photojournalists have different views of what is acceptable manipulation of news photographs, and that their reasons for this will also be different. This thesis also suggests that the manipulation of news photographs is ethically problematic and can damage the credibility of both the photojournalist and the publication in which the photographs appear. The study involves a comparison of the results from a questionnaire given to South African photojournalists and a similar questionnaire given to American photojournalists. The questionnaires were then supplemented by interviews with six South African photojournalists. The thesis then draws conclusions from the responses to the questionnaires and interviews. These conclusions partially support the initial hypothesis, in that there are some differences between the views of South African and American photojournalists, but, on the whole, these are remarkably similar. Photojournalists do seem to find the manipulation of news photographs to be ethically problematic, but they may find the manipulation of other kinds of images (eg fashion or soft news) to be acceptable. South African photographers also find the manipulation of images by other means (eg different lenses or darkroom techniques) to be more acceptable than Americans do. Although the underlying reasons for these views may differ, maintaining the credibility of the photographer and the publication does seem to be the major issue for avoiding digital manipulation. South African photographers seemed to think that if the photographer had done his or her job well, there would be no need for manipulation, and both groups (but especially the Americans) felt that manipulation could often be equated to lying to the reader, and that this might damage their reputation, and that of their publications.
- Full Text:
- Date Issued: 1999
A participant-focused sociological analysis of Beedz, a Grahamstown skills training project for women
- Authors: Bobo, Azola Benita Dorothea
- Date: 2017
- Subjects: Beedz (Makhanda, South Africa) , Feminist theory -- Developing countries , Training -- South Africa -- Makhanda , Occupational training -- South Africa -- Makhanda , Women -- South Africa -- Makhanda -- Social conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/5686 , vital:20964
- Description: This research looked at a participant-focused sociological analysis of Beedz, a Grahamstown skills training project for women. Beedz is run by the River of Life Church and aims to equip women with the necessary skills to participate in the economy, either as entrepreneurs or as employees. Using third world feminist theory, this research explored the experiences of women who have participated in the Beedz programme, what they went through, and whether the programme benefited them or not. In particular, this research explored how the participants experienced Beedz as a programme for women without an exclusive focus on traditional feminist issues. This research was qualitative in nature; with in-depth, semi-structured interviews being used as a means of data collection. Data was analysed using key themes emerging from the interviews. The key findings of this research were that it is important to include women in training projects, as by including them you create spaces and enabling environments for women to empower themselves. Secondly, although Beedz does not deliberately work from the third world feminist theory, it could be argued that it fits in this framework as this programme facilitates skills training through looking at women as a whole, taking into account not only their gender, but also their class and race. Recommendations were made on how the Beedz programme may be improved, based on the information gathered from the participants from the interviews conducted during the research, with the key recommendation being that the organisers of the programme need to create a space for the participants’ voice to be heard, so that the programme can be relevant and beneficial to them.
- Full Text:
- Date Issued: 2017
An exploration of whether using a global employment company could mitigate the South African tax risks in relation to inbound expatriates in multinational companies
- Authors: Pavey, Janet Gail
- Date: 2018
- Subjects: Double taxation -- South Africa , Corporations, Foreign -- South Africa , Foreign workers -- Taxation -- South Africa , International business enterprises -- South Africa , Corporations -- Taxation -- South Africa , Value-added tax -- Law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/61368 , vital:28019
- Description: The main objective of this research paper was to explore whether a multinational company could use a global employment company to employ its expatriates to mitigate, simplify or limit the tax risk for that foreign company when sending expatriates to South Africa. To investigate this topic, an interpretive research approach was used, a doctrinal research methodology was followed, and inductive reasoning was applied. The documentary data used in this research was publicly available. Firstly, the meaning of the term “expatriate” was explored, together with the types of employment arrangements commonly used to employ this type of employee. The South African tax consequences that an inbound expatriate may create for a multinational company were then analysed. These tax consequences were applied to the common types of employment arrangements to determine what the South African tax impact of these arrangements is likely to be and which entity within a multinational group is likely to be affected. It was investigated whether using a foreign global employment company provides any tax simplification or tax mitigation strategies for the multinational company for expatriates inbound to South Africa. The primary conclusions of this research were that it was found that using a global employment company may only provide a tax benefit in South Africa in very specific circumstances: (i) where the economic employer of the expatriate is the South African entity; (ii) where flexibility is required to easily move the expatriate to other jurisdictions; and (iii) where there are multiple home-host country combinations that the multinational group needs to consider when moving its expatriates. It would appear that using a global employment company as the employment arrangement for an inbound expatriate to South Africa may have a fairly limited application if its purpose is to mitigate tax risks. In effect, a global employment company is likely to provide tax benefits only where it acts as an international labour broker for the multinational company of which it is a part.
- Full Text:
- Date Issued: 2018
Biogeomorphic aspects of lichen colonisation in part of western Dronning Maud Land, Antarctica
- Authors: Ayres, Gabrielle Alexzena
- Date: 2017
- Subjects: Lichen communities -- Queen Maud Land , Lichens -- Ecology -- Queen Maud Land , Polar regions , Ecology -- Polar regions , Antarctica , Ecology -- Antarctica
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/19713 , vital:22477
- Description: Ice-free regions in Antarctica provide natural laboratories for investigating and modelling change in landscapes and ecosystems. The terrestrial ecosystems in western Dronning Maud Land are potentially critical to improve current understanding of polar ecosystems, however, they remain poorly represented and under-protected. Lichen habitats were used to elucidate geomorphic-biological feedbacks that shape the landscape’s topography and biodiversity, which in turn promote environmental heterogeneity. Environmental parameters acting on two landforms were measured to determine the colonisation and growth of lichens in niche habitats. The habitats were identified and characterised, and topographic heterogeneity was found to control lichen colonisation. Micro-topographical niches provide the most stable environments for colonisation, and are preferred habitats. Lichen-habitat interactions were species specific, and closely related to insolation and moisture availability. The bidirectional relationships between rock weathering and lichen colonisation was ascertained. Results showed that lichens are good indicators of landform heterogeneity, but also promote landform heterogeneity. Given the habitat preferences of specific lichen species, they provide proxy to evaluating environmental responses, especially environmental change. The findings of this research are to be used as baseline data for future studies exploring ecosystem development in emerging landforms.
- Full Text:
- Date Issued: 2017
Disturbing the neighbours: an investigation into the relationship between psychopathology and social formations
- Authors: Collins, Anthony
- Date: 1995
- Subjects: Freud, Sigmund, 1856-1939 , Winnicott, D. W. (Donald Woods), 1896-1971 , Social psychiatry , Social psychology , Psychology, Pathological , Frankfurt school of sociology , Political psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2953 , http://hdl.handle.net/10962/d1002462 , Freud, Sigmund, 1856-1939 , Winnicott, D. W. (Donald Woods), 1896-1971 , Social psychiatry , Social psychology , Psychology, Pathological , Frankfurt school of sociology , Political psychology
- Description: This work attempts to confront certain political problems created by the individualistic bias in psychoanalytic thinking, and the resulting failure to adequately theorise the importance of social processes. The thesis traces the origins of intrapsychic thinking to Freud's initial move from the seduction theory to the Oedipal theory. This development is offered as a prototype for the debates between conceptualisations of childhood traumatisation as a social problem of actual abuse occurring within dermed power relations, and theories which locate pathology purely within internal conflicts occurring inside the individual. Several criticisms of this shift are offered, and it s impact on later theory is considered. Here a contrast is offered between the theoretical approaches of Melanie Klein and Donald Winnicott, arguing for the usefulness of Winnicott's emphasis on environmental factors within psychodynamic theory. The impact of these theoretical approaches is illustrated through a critical evaluation of Freud's case study of Judge Schreber. Additional historical material is brought in to show the importance of environmental considerations ignored by Freud, and contrasting psychodynamic readings of the case are offered. As an alternative to purely intrapsychic approaches, a reinterpretation of certain strands of Critical Theory is then presented. Adorno's theory of the Authoritarian Personality and Marcuse' s concept of One-Dimensional Man are extended using Winnicott's formulations concerning psychological development. This leads to an examination of the question of the relationship between social structure and individual consciousness. Post-structuralist accounts of language and the construction of identity are explored. These are then developed drawing on theories of ideology, language and consciousness, integrating these with Winnicott's developmental theory to offer an alternative psychodynamic understanding of the relationship between social process and psychopathology. An attempt is made to reformulate - the notions of consciousness and the unconscious in terms of the possibilities and difficulties of representation within available social symbolic codes. In conclusion the it is argued that psychology needs to integrate critical social theory and contemporary understandings of the social construction of consciousness in order to become a meaning force in positive social transformation.
- Full Text:
- Date Issued: 1995
Exploring the meaning of informal social alcohol consumption rituals in performing masculinity amongst male university students
- Authors: Makgale, Obakeng
- Date: 2019
- Subjects: College students -- Alcohol use , Drinking of alcoholic beverages -- South Africa , College students -- Conduct of life -- South Africa , Male college students -- Conduct of life -- South Africa , Masculinity
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96680 , vital:31308
- Description: Alcohol use amongst university students has received a significant amount of attention in different countries across the world (Dempster, 2011; Kobin, 2013; Maphisa & Young, 2018). The purpose of this study is to explore the meaning of informal social alcohol drinking rituals in performing masculinity amongst male university students. This study used a Social Constructionist approach to gender as theoretical framework. Thus, gender is understood as constructed through social interactions, where a person performs their masculinity before an approving audience (Butler, 2009; Sallee, 2011). This research employed a qualitative research approach. Four participants were selected for in-depth interviews which were analysed using Thematic Network Analysis (Attride-Sterling, 2001). Two global themes emerged from the data set. The first global theme focused on “Men and Alcohol” and concerns the facilitative role that alcohol use and tolerance plays in masculine performance, exploring how masculinities compete for the hegemonic position through excessive alcohol use. The second global theme concerns the “Wolf Pack” and focuses on how peer groups engage in informal social drinking rituals and how these rituals function within the group dynamic. Informal social drinking rituals appear to play a significant role in successful display of hegemonic forms of masculinity in this context, and also play a significant role in expanding one’s social network. However, the consequences associated with this social practice places one in the position of having to maintain participation in heavy drinking in order to feel secure, leaving one vulnerable to negative consequences associated with excessive drinking.
- Full Text:
- Date Issued: 2019
Integrating local knowledge when mediating learning of food preservation in a Namibian multicultural Grade 6 class
- Authors: Shetunyenga, Shetunyenga Fillipus
- Date: 2020
- Subjects: Food -- Preservation -- Study and teaching (Elementary) -- Namibia , Ethnoscience -- Study and teaching (Elementary) -- Namibia , Ethnoscience -- Namibia , Education, Elementary -- Namibia , Multicultural education -- Namibia
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/163602 , vital:41052
- Description: The challenge posed by multicultural classrooms has been acknowledged in many studies. Some scholars believe that the knowledge learners bring to school from their homes or community forms a basis for the knowledge to be acquired at school. That is, if learners’ cultural experiences and/or indigenous knowledge are integrated into teaching of science, learners might make good sense of science. Even though the Namibian National Curriculum has responded well to the calls of recognising and integrating indigeno us knowledge during teaching and learning, it has failed to provide guidance on how this should be done. Therefore, there is a need to minimise the gap between the intention of the National Curriculum and the implementation of this intended curriculum at classroom level. It is against this background that this study sought to investigate whether or not learners’ conceptions and attitudes are influenced by integrating local or indigenous knowledge when teaching food preservation in a Namibian multicultural classroom context. Underpinned by an interpretive paradigm, the study took the form of a mixed-method case study approach. It was conducted at an urban combined school in the Oshana region, Namibia. The sample consisted of 29 Grade 6 learners doing Agricultural Science, the grade 6 Agricultural Science teacher and four community members from different cultural groups. The community members were invited to demonstrate how they culturally preserve mahangu (wheat), fish, milk, and meat in their respective cultures. Data were generated using the pre-and post-intervention questionnaires, a group activity, observations (videotaped lessons) and learners’ journal reflections. Quantitative data from the pre- and post-intervention questionnaires were analysed deductively and presented in tables and graphs. On the other hand, a thematic approach was used to inductively analyse qualitative data, where Vygotsky’s (1978) socio-cultural theory was used as a theoretical lens focusing on culture, mediation, and social interactions. The findings of this study revealed that learners’ conceptions, attitudes, and interest shifted positively as a result of the integration of local or indigenous knowledge on food preservation. Additionally, during the presentations by the community members, learners were actively engaged, asking questions and showing interest in learning about other cultures. The study thus recommends that Agricultural Science or science teachers should, where possible, make efforts to integrate local or indigenous knowledge in their multicultural classrooms.
- Full Text:
- Date Issued: 2020
Ionospheric total electron content variability and its influence in radio astronomy
- Authors: Botai, Ondego Joel
- Date: 2006
- Subjects: Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5473 , http://hdl.handle.net/10962/d1005258 , Electrons , Global Positioning System , Global Positioning System -- Data processing , Ionosphere , Ionospheric radio wave propagation
- Description: Ionospheric phase delays of radio signals from Global Positioning System (GPS) satellites have been used to compute ionospheric Total Electron Content (TEC). An extended Chapman profle model is used to estimate the electron density profles and TEC. The Chapman profle that can be used to predict TEC over the mid-latitudes only applies during day time. To model night time TEC variability, a polynomial function is fitted to the night time peak electron density profles derived from the online International Reference Ionosphere (IRI) 2001. The observed and predicted TEC and its variability have been used to study ionospheric in°uence on Radio Astronomy in South Africa region. Di®erential phase delays of the radio signals from Radio Astronomy sources have been simulated using TEC. Using the simulated phase delays, the azimuth and declination o®sets of the radio sources have been estimated. Results indicate that, pointing errors of the order of miliarcseconds (mas) are likely if the ionospheric phase delays are not corrected for. These delays are not uniform and vary over a broad spectrum of timescales. This implies that fast frequency (referencing) switching, closure phases and fringe ¯tting schemes for ionospheric correction in astrometry are not the best option as they do not capture the real state of the ionosphere especially if the switching time is greater than the ionospheric TEC variability. However, advantage can be taken of the GPS satellite data available at intervals of a second from the GPS receiver network in South Africa to derive parameters which could be used to correct for the ionospheric delays. Furthermore GPS data can also be used to monitor the occurrence of scintillations, (which might corrupt radio signals) especially for the proposed, Square Kilometer Array (SKA) stations closer to the equatorial belt during magnetic storms and sub-storms. A 10 minute snapshot of GPS data recorded with the Hermanus [34:420 S, 19:220 E ] dual frequency receiver on 2003-04-11 did not show the occurrence of scintillations. This time scale is however too short and cannot be representative. Longer time scales; hours, days, seasons are needed to monitor the occurrence of scintillations.
- Full Text:
- Date Issued: 2006
NUMSA - Motor industry participants workbook
- Authors: NUMSA
- Date: July 1998
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/117852 , vital:34564
- Description: Industrial Councils were established in terms of the 1924 Industrial Conciliation Act (ICA). Even with the ICA giving way to the LRA of 1956, Industrial Councils remained the central forums for collective bargaining. Because African workers were excluded from the definition of an "employee" both in the ICA & LRA of 1956, African workers and their unions did not participate in Industrial Councils. As a result of this the.Councils were then used by white unions to promote the interests of skilled white workers. This situation only partially changed in 1979 when the LRA was changed to give African workers bargaining rights. From then on African workers and their unions could participate in Industrial Councils.
- Full Text:
- Date Issued: July 1998
On the characterisation of copper indium diselenide based photovoltaic devices
- Authors: Thantsha, Nicolas Matome
- Date: 2006
- Subjects: Photovoltaic cells
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10536 , http://hdl.handle.net/10948/443 , Photovoltaic cells
- Description: Photovoltaic (PV) modules based on thin film systems of CuInSe2 (CIS) and its alloys on low cost substrates are promising candidates to meet the long term efficiency, reliability and manufacturing cost goals. The attention to the CIS solar cell technology is because of the high absorption coefficient of the solar cell absorber layer. Solar cells and PV modules are conventionally assessed by measuring the currentvoltage characteristic of the device. This thesis presents an assessment procedure developed capable of assessing the device parameters with reference to I-V measurements. This thesis then characterizes the performance of the CIS based solar cells and modules in conjunction with other PV modules of different technologies such as crystalline Silicon modules by analyzing the light and dark I-V measurements of the devices. The light and dark I-V characteristics of PV devices were investigated and device parameters were extracted from the I-V data. The extraction and interpretation of these device parameters has a variety of important applications. It has been proven that the device parameters can be used for quality control during production and to provide insights into the operation of the PV devices, thereby improving the efficiency of the devices. The assessment comprises light I-V measurements at standard test conditions (STC), irradiance dependence measurements, parasitic series and shunt resistances measurements and the dark I-V measurements of the PV devices. The PV modules assessed comprise different technologies, namely, thin film based modules (CIS and a-Si) and multicrystalline Si and Edged-defined Film-fed Growth Si (EFG-Si). The dark I-V measurements results showed that the EFG-Si module has acceptable shunt (900 W) and series (0.4 W) resistances, thereby leading to the higher power output depicted from the light I-V measurements. The low quality cells of a-Si module were so low that the fill factor was the smallest (43%). In addition, the dark I-V measurements results revealed that CIS modules are less dependent to temperature at high voltages.
- Full Text:
- Date Issued: 2006
Optimisation of an in vitro model for anti-diabetic screening
- Authors: Wilson, Gayle Pamela
- Date: 2006
- Subjects: Hypoglycemic agents , Diabetes -- Treatment -- South Africa , Materia medica, Vegetable -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10308 , http://hdl.handle.net/10948/428 , Hypoglycemic agents , Diabetes -- Treatment -- South Africa , Materia medica, Vegetable -- South Africa
- Description: The need for alternative strategies for the prevention and treatment of diabetes is growing rapidly as type II diabetes is reaching epidemic status in our society. This need was the basis for the creation of this study, as it was necessary to start looking towards medicinal plants as potential antidiabetic treatment and no comprehensive in vitro model existed. In creating a model for determining the effects of alternative traditional medicines as antidiabetic potentiates, it was necessary that two metabolic pathways, namely glucose uptake and insulin secretion, which play a significant role in glucose homeostasis, be at the centre of our investigations. The objective of this project was to optimize the methodology required to screen and ultimately determine the effectiveness of the plant extracts Kankerbos and MRC2003, as antidiabetic potentiates, through observing their effects on glucose utilisation and insulin secretion. If these medicinal plants are going to make a positive contribution to the health of type II diabetic South Africans, then the determination of their efficacy is essential. The cell lines used in this study included 3T3-L1 preadipocytes, Chang liver, C2C12 muscle and INS-1 rat pancreatic cells. Each cell line represents a different in vivo organ that is known to have an influence on glucose homeostasis in our bodies, each with its own unique metabolic pathways and mechanisms of activity, thereby making each one a vital component in the study. The positive controls for the two models were insulin and metformin (glucose utilisation) and glibenclamide (insulin secretion). Insulin was shown to provide a significant increase in the amount of glucose taken up in C2C12 muscle and Chang liver cells for acute conditions. Chronic treatments with metformin provided a significant increase in glucose utilised by Chang liver cells. Glibenclamide was an effective positive control for stimulating insulin secretion by INS-1 cells under acute conditions as there was a significant increase in the amount of insulin secreted. MRC2003 did not show any significant antidiabetic activity. Sutherlandia frutescens (Kankerbos) showed biological activities comparable to some of the more recognized antidiabetic compounds throughout the study. With regards to the glucose utilisation model, Kankerbos was seen to have both acute and chronic effects in different cell lines. In the C2C12 muscle cell line, Kankerbos significantly increased glucose uptake when they were exposed to acute conditions. Kankerbos also had a significant effect on the Chang liver cells as it was observed that under both acute and chronic conditions, this plant extract induced the uptake of glucose into these cells. With respect to the insulin secretion model involving INS-1 cells, no significant effect was seen during acute exposure with Kankerbos treatment. However during chronic exposure, an increase in insulin secretion was initiated by this plant extract. Overall, the results of this study suggest that Kankerbos has a twofold mechanism of action for its glucose-lowering effects. Given that Kankerbos is widely available in South Africa, this study was valuable as it provided an indication that Kankerbos has antidiabetic activities and could possibly be used as an alternative antidiabetic medication.
- Full Text:
- Date Issued: 2006
Symmetry and asymmetry in electrocatalysis: enhancing the electrocatalytic activity of phthalocyanines through synergy with doped graphene quantum dots
- Authors: Nkhahle, Reitumetse Precious
- Date: 2020
- Subjects: Phthalocyanines , Quantum dots , Graphene
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/117585 , vital:34529
- Description: An exploration on the enhancement of the electrocatalytic activity of phthalocyanines (Pcs) through coupling with a series of graphene quantum dots (GQDs) is undertaken. The preliminary studies using symmetrical Pcs, a cobalt and an iron chloride tetra substituted diethylaminophenoxy Pc (complexes 1 and 2), for the electro-oxidation of nitrite revealed through the various sequential modifications that doped GQDs fare better than their pristine counterparts with respect to improving the electrocatalytic behaviour of Pcs, in particular, the nitrogen-doped GQDs (NGQDs). Following up on this, a series of asymmetric Pc complexes; 2,9,16-tris-(4-tert-butylphenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (3), 2,9,16-tris-(4-tert-butylphenoxy) mono aminophenoxy phthalocyanato cobalt (II) (4), 2,9,16-tris-(3-diethylamino)phenoxy) mono carboxyphenoxy phthalocyanato cobalt (II) (5) and 2,9,16-tris-(3-diethylamino)phenoxy) mono aminophenoxy phthalocyanato cobalt (II) (6) was prepared in which push-pull systems were compared to other asymmetric complexes that lack this effect towards the electrocatalytic sensing of hydrazine. All asymmetric complexes (3-6) were π-stacked to the NGQDs while those with an NH2 group (4 and 6), were also covalently linked to the NGQDs. These complexes and their corresponding conjugates were characterized accordingly and applied as electrocatalysts in the oxidation of hydrazine. The electrochemical studies revealed that π π stacking yields better responses (higher sensitivities and lower limits of detection) than covalent linking because there are less forces acting on the graphene network. Covalent linking introduces both tensile and compressive forces which in turn results in an increase in the ID/IG ratio and that is unfavourable for electrocatalysis. In comparing the electrodes composed of the π-stacked conjugates to those altered through sequential modifications, despite the conditions not being the same, it can be inferred that the magnitude of the electrostatic forces between the Pcs and the GQDs also plays a significant role in electrocatalysis. The π-stacked conjugates, owing to the manner in which they were prepared, have stronger electrostatic forces acting between the Pc and GQDs hence they were able to elicit a better electrochemical response than the sequentially modified electrodes. In addition to that, it appears that asymmetric Pcs are better electrocatalysts in comparison to the symmetric Pcs.
- Full Text:
- Date Issued: 2020
The effects of elevated atmospheric CO2 on the biological control of invasive aquatic weeds in South Africa
- Authors: Baso, Nompumelelo Catherine
- Date: 2020
- Subjects: Aquatic weeds -- Biological control -- South Africa , Plants -- Effect of atmospheric carbon dioxide on , Atmospheric carbon dioxide -- Environmental aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/140772 , vital:37917
- Description: There has been a rapid increase in atmospheric CO2 concentration, from pre-industrial values of 280 ppm to more than 400 ppm currently, and this is expected to more than double by the end of the 21st century. Studies have shown that plants grown above 600 ppm tend to have an increased growth rate and invest more in carbon-based defences. This has important implications for the management of invasive alien plants, especially for the field of biological control which is mostly dependent on herbivorous insects. This is because insects reared on such plants have been shown to have reduced overall fitness. Nevertheless, most of the studies on potential changes in plant-insect interactions under elevated CO2 are based on agricultural systems, with only a limited number of these types of studies conducted on alien invasive weeds. However, climate change and invasive species are two of the most prevalent features of global environmental change. Therefore, this also warrants active research and experimental studies to better understand how these systems will be affected by future climates. Thus, the aim of this study was to investigate the effects of elevated atmospheric CO2 on the biological control of four invasive aquatic weeds (Azolla filiculoides, Salvinia molesta, Pistia stratiotes, and Myriophyllum aquaticum). These species are a threat to natural resources in South Africa but are currently under successful control by their biological control agents (Stenopelmus rufinasus, Cyrtobagous salviniae, Neohydronomus affinis, and Lysathia n. sp.). To achieve this, the selected plant species were grown in a three-factor experimental design in winter (CO2 X nutrients X herbivory), and another two-factorial design in summer (CO2 X herbivory). Atmospheric CO2 concentrations were set at ambient (400 ppm) or elevated (800 ppm), as per the predictions of the IPCC. As per my hypothesis, the results suggest that these species will become more challenging in future due to increased biomass production, asexual reproduction and a higher C: N ratio which is evident under high CO2 concentrations. Although the biological control agents were in some instances able to reduce this CO2 fertilisation effect, their efficacy was significantly reduced compared with the levels of control observed at ambient CO2. These results suggest that additional biological control agents and other management methods may be needed for continued control of these invasive macrophytes, both in South Africa and further afield where they are problematic.
- Full Text:
- Date Issued: 2020
The importance of personal and collective resources in coping with stressors related to industrial action at the Coldstream sawmill
- Authors: Besseling, Elizabeth Anne
- Date: 1999
- Subjects: Stress (Psychology) , Stress (Physiology) , Industrial relations -- South Africa -- Case studies , Coldstream (South africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2932 , http://hdl.handle.net/10962/d1002441 , Stress (Psychology) , Stress (Physiology) , Industrial relations -- South Africa -- Case studies , Coldstream (South africa)
- Description: The main purpose of the study is to investigate whether the stress response moderators served as effective variables in reducing the stress of the strike. For instance, if individuals differ in' their ability to actualise resources, does someone with a high SOC utilise friendships or supportive relationships more than someone with a low SOC? Does someone who has a high score for religious practice become less depressed when faced with a significant stressor than someone less involved in church activities?
- Full Text:
- Date Issued: 1999
The use of ritual as physical and spiritual medium and its documentation in Buhlebezwe Siwani’s contemporary visual arts performance
- Authors: Lila, Philiswa
- Date: 2020
- Subjects: Arts and religion , Ritual -- South Africa , Performance art -- Religious aspects -- South Africa , Women performance artists -- South Africa , Siwani, Buhlebezwe, 1987-
- Language: English
- Type: text , Thesis , Masters , MFA
- Identifier: http://hdl.handle.net/10962/166160 , vital:41334
- Description: This thesis is motivated by my experience of Inzilo: Ngoba ngihlala kwabafileyo, a live performance by South African visual artist Buhlebezwe Siwani. The performance took place at Michaelis Galleries, University of Cape Town (UCT), as part of a group exhibition Between Subject and Object: human remains at the interface of art and science (2014), which accompanied the Medical Humanities in Africa Conference (from 28 – 29 August 2014). As an entry into my discussion, I describe how Siwani’s performance makes use of death and burial ritual in what seems to be an intention to make art that is (re)presenting an activity of reality to invade and control the sphere of feelings, emotions and a sense of ceremony that is dependent on both ritual and rites of the performance. I grapple with the fact that I experienced a ritual performance in a gallery space. Furthermore, I question how walking out of the performance I thought of the lines between art and/or life. The role of ritual in my thesis explores the symbolic meanings, powers and intentions of ritual rites in Africa. This reflection maps out historical locations that are relevant to the major debates, definitions, themes and the experiences of ritual as part of academic research. From Siwani’s practice as an artist and isangoma to other expressions in the fields of history, sociology, religion, feminism, to mention a few, my thesis is an enquiry that engages ritual and performance art theory and scholarship. Through a qualitative analysis, my methodology rejects a chronological, thematic and discipline centered research. Rather, I use a multidisciplinary approach based on critical visual analysis as knowledge creation in the visual arts, for example archives, documentation, performance, text, video, installation, painting, sculpture, etc. The findings suggests that the role of ritual in performance art is not a singular exploration, nor is it based on separating ritual and performance art. The results further reveal that ritual in performance art is not a reenactment of patterns and human behaviours, nor is the notion of reenactment used to denote the myriad meanings and functions of re-performing historical ritual events into performance art. Throughout, my thesis provides a focus that demonstrates the significance of how ritual in performance art has a profound subjective (personal or individual) and collective holistic way of serving human and spiritual needs, and that of creating an environment that is open to the content and context of art as it relates with traditional African religious practices, beliefs and knowledges. Focus is given to three major themes that make up the three chapters of my research: firstly, I reflect on death as personified by Siwani’s performance Inzilo: Ngoba ii ngihlala kwabafileyo and her role as isangoma. Here death is used to draw specific attention to the body in process of embodied presence and absence of physical and spiritual worlds. Secondly, drawing on Siwani’s concept of secrecy and boundaries of concealing and revealing rituals meanings and powers as isangoma, I question the role of secrets, which highlights the significance of bodies (human and natural sites of ritual) in ritual performance. Finally, the idea of a trace is explored. The intersecting use of a trace as the thinking-making-doing of ritual in performance articulates a connected thread that sets in motion the trace of ritual (installation, image and marked space pf ritual) as an afterlife that offers a continued space of processual ceremony for multiple effective encounters and movements..
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- Date Issued: 2020